Wednesday, October 31, 2012

Another Nor'easter Threatens East Coast

In the wake of Sandy, another Nor'easter is projected to develop in the next 5-10 days. The above map shows 500mb winds for the time period that we are watching. The presence of such strong winds indicates that a strong low pressure system is in the area. What makes this situation even more interesting is how the system appears to be tilting to the southeast, or being negatively tilted. A negatively tilted storm typically includes more gusto in that it provides more severe weather potential in the summer, and thus heavier precipitation potential in the winter. But, will this actually put down some of the whit stuff? Let's take a look.

The precipitation forecast for the same time period as above shows pretty low amounts of precipitation across the Northeast as the system slides to the east. This isn't too interesting to me, and I can't really say I believe it. We are dealing with a strengthening storm system, this should have more precipitation than this model is showing.

This is a thickness forecast at the 1000-500mb level. This map is best used to identify the rain/snow line. Snow would be expected north of the dark blue line labelled 540 (or 5400), and rain would be located to the south of the line. If we compare the precipitation chart to this thickness chart, we see that the air mass behind the Nor'easter would appear to be favorable for some snow. However, models have been known to take a cold bias in the fall, and thus my confidence in such a favorable environment for snow deteriorates.

This will be interesting to watch, but I don't have enough confidence to make a call just yet.


Northern Hemisphere Snow Well Above Normal

Northern Hemisphere snow cover is running well above normal on this Halloween 2012, as recent building of snow across Canada and northern Russia adds to the above normal count.

You're probably thinking: Why should I care about Siberia? 

Well, studies have proven that October snowfall in Siberia correlates well with winter conditions in North America. These studies have shown that, in above normal snowfall cases in Siberia, a negative Arctic Oscillation, or AO develops. This negative AO provides a base for cold air to drop into the United States. In a positive AO, warm air holds its ground in the Lower 48. 

However, it appears that only October matters for this theory. Last year, snowfall was below normal in October yet above normal in November. As the studies indicated, warm air was then favored across the Lower 48, and this forecast did indeed verify.

Now, in October 2012, we found ourselves with the following:
-Slow start to snow cover in early October
-Gradual building of snow cover in mid October
-Burst of snowfall in late October

If we apply this to the correlation with the Arctic Oscillation, one would think that this winter will start out on the warm side, before gradually turning cooler. Late in the winter, it would be expected that a very frigid air mass would enter the United States and make for a brutal end of winter. However, because this is just one puzzle piece in an extremely complicated puzzle, this is in no way set in stone, nor is it my forecast. This is what would be expected to happen if this theory were the only factor that forecasted this winter.


Long Range Lookout: Stormy Pattern Continues in Northeast

This is the October 31, 2012 edition of Long Range Lookout.

After the devastation Superstorm Sandy caused across the Northeast, many are likely to be wary when I say that a general stormy pattern looks to take hold across the region. The ECMWF ensembles, shown above in a 500mb height anomaly chart for the next 6-10 day period, shows a ridge building across the West and a stormy signature in the East.

This is shown in model forecasts as coming in at least two systems, which could both hold the potential for some flying snowflakes, however that has yet to be nailed down as a possibility.

Something that is puzzling to me is the lack of a clear negative NAO signature, something that commonly defines a stormy Northeast period. Instead, Greenland seems to be in between a ridge in the south and a stormy pattern to the north. Additionally, other ensemble forecasts are playing out a positive PNA heading negative and a negative NAO heading positive, both of which bode well for a storm track away from the Northeast.

Despite these unknown elements, I believe that the ECMWF Ensembles are on track with this forecast, as other models are showing very similar conditions to the scenario depicted above.


Tuesday, October 30, 2012

Early Look At Summer/Fall 2013 Reveals La Nina Potential

A look at preliminary long range forecasts from several models indicate that there is indeed potential for a La Nina to develop going into the sumer and fall months. The CCA and CA models, used by the Climate Prediction Center, are forecasting similar situations for the ENSO situation in that they both have a weak La Nina ongoing in the JAS (July-August-September) to NDJ (November-December-January) and possibly beyond that.

It should be noted that these two models are practically the same and are two models of several. That said, take these two for what they're worth, which isn't much for this far out.

This is an ensemble set from the CA model that was described above. The ensembles are in color, and the CA is in black. If we see the ensembles, we can see that the ensembles are in a fair spread, with a few heading to a moderate La Nina and a few others are more in the neutral ENSO situation for fall into early winter.

If you look beyond the fall forecast, you can see that DJF (December-January-February) has all ensemble members in a La Nina, which is something you may want to keep in mind...


What Are The Models Saying This Winter? Part 2

After I saw how much you all enjoyed the first post on what the models are saying for this winter, I figure you might like another post, examining other models and what their take on winter is.

This is the temperature (top) and precipitation (bottom) forecast from what is referred to as the 'CMC1'. This model appears to be based off the CMC model, which doesn't have the best reputation for forecasting. This particular forecast includes a cooler than normal Northwest US, but that's about it as far as below normal temperatures go. Above normal temperatures are found in the entire East US, where anomalies are as high as 3 degrees above normal. As for precipitation, the West Coast is very much below normal, indicating that the storm track wouldn't be too active if this were to verify. The Midwest, Plains and Ohio Valley would be wetter than normal, however, and the Southeast would be below normal. This makes sense, as this resembles a positive PNA scenario and would be very beneficial to the Midwest/Ohio Valley/Plains. However, because the LRC has not taken storms along this path too much, I can't say I'm too confident in it.

I don't really like this forecast because we are about to commence a West-Based El Nino as seen in today's post (click here), and in a West-Based El Nino, you find a warm West US and cool East US. However, when it comes down to it, the El Nino is one of dozens of factors for this winter.

The next forecast of precipitation (top) and temperatures (bottom) comes from the GFDL model, commonly known as one of the hurricane models. The GFDL model shows a very dry Northwest US and below normal Northeast, Great Lakes and Midwest in terms of precipitation. There is a swath of above normal precipitation in the Southeast, however. As for temperatures, a below normal swath of temperatures is found across the Northwest and Northern Plains, while a warmer than normal forecast includes the Plains and Southeast. I can't say I trust this forecast. If you see the warmer than normal water anomalies in the upper right part of the image, you are seeing a negative NAO set-up. This commonly gives the East cool weather. Considering the month of October has been in a negative NAO and Siberia is above normal in snowfall, I disagree with this forecast.

If you like these model forecasts, I will keep putting up more model forecasts when I have the time.


Monday, October 29, 2012

2 Feet of Snow Yet To Fall in WV

As Superstorm Sandy continues to barrel into the Northeast and Mid-Atlantic, West Virginia is still under the gun for over 24 inches of snow in the next 14 hours.

The HRRR, or Hi-Res Rapid Refresh model, is a short range model used for forecasting events that are in the 0-15 hour timeframe. This is the 14 hour total accumulated snow for the Northeast, and as you can see, West Virginia gets absolutely crushed with another 2 feet of snow yet to fall on top of snow that has already fallen. Should this forecast verify, some isolated locations could be flirting with the 3 foot mark- quite a way to start the winter season.

Also of note is that Ohio and Michigan could get some snow in the next 14 hours. Ohio could get 1-3 inches in the western half of the state, while eastern Michigan could get as much as 2 inches in spotty areas. This is only going to be a major event for West Virginia- all other areas should get minor accumulations.


"He's Baaaack!"; El Nino Returns

The El Nino, once thought to be gone, has made a sudden reappearance in the face of what could have been a growing threat of a La Nina.

This past week has brought a new body of warmer than normal water over the western ENSO region, and this can only mean one thing: the El Nino has returned. I declared a few months ago that the El Nino was dead, and I stand by that post. What it did was die off on the surface but remain 'dormant' underwater. It is only now that we are seeing this underwater warm pool move towards the surface, and in response we see this new El Nino-style body of water.

Remember when I started saying that there was cooling that resembled a La Nina? Well, it died off. It's still there, and you can see the blue blob off the coast of South America on the image above. However, as it began moving west, there was no sustained cooling in its original formation along the coastline. That said, this scare is over.

So, all is back to normal. The El Nino seems to have returned, and will strengthen if the underwater warm pool continues to move towards the surface. Considering it's west-based this time around, the temperature anomalies favor a warm West US and cool East US, as shown below.


What The LRC Is Saying About This Winter

The above image is of observed precipitation and storm tracks, with the strength of those storms on the bottom of the image. All you might see is lines and colors. But this actually holds the key to deciphering the LRC, or Lezak Recurring Cycle.

But before we sort this all out, what is the LRC?

The Lezak Recurring Cycle is:
•A weather pattern that sets up every year.
•This pattern is NEVER THE SAME from year to year.
•Pattern sets up in late fall-early winter.
•The LRC cycles (repeats) through the winter and spring from the original pattern in the fall.
•Each cycle is 40-60 days.

For example, if a system were to go through the Midwest in mid October and brought a lot of rain to the region, you might see the storm again in December (40-60 days later) in the Midwest again with a lot of precipitation. However, strength and track varies with each cycle.

Looking at the graphic above, we see a lot of lines going through the Plains and Midwest. This correlates well with the precipitation being centered in the southern Plains and Midwest. If we put the LRC to use in this 30 day observation, one would think that the Midwest and Plains will bear the brunt of storms this winter.

And here's the thing- I believe it.

A consistent positive Pacific-North American (PNA) phase makes for a wet and stormy Midwest and Northeast. The PNA was observed to be variable in the last month, but a consistent negative North American Oscillation (NAO) changed the jet stream to give a lot of cold to the East US. If we put these two together, we get a wet, cold East US.

Things are still developing, but this is a great sign for those wishing for a snowy winter in the Midwest and Plains.


Superstorm Sandy Closing In on Northeast

Satellite imagery indicates that Superstorm Sandy is now moving quickly west, much further west than originally forecasted. Additionally, and more importantly, Sandy appears to still have a defined center.

There is a pretty sturdy eyewall surrounding this center, and cloud tops on this infrared imagery are colder than its surrounding convection to the west.

As the storm moves further west, water is expected to rapidly move west as well, likely flooding out beaches and going inland. However, the big concern is high tide. High tide is expected to occur this evening, between the 8-9 PM hour. When this happens, it is likely that the worst flooding of this storm will occur. Storm surge as high as 12 feet, combined with high tide, extreme winds and heavy rain will lead to a perfect combination of a terrible flooding situation.

I am expecting widespread power outages across the entire Northeast and Mid-Atlantic as Sandy comes ashore. These outages are most likely along the coast, and that is where outages should be the most widespread. I feel that New York City will also bear quite a brunt, and Long Island will definitely get in the action. However, the worst power outages will be in New Jersey and the Delmarva area.

There is a less likely area of power outages to the west, where cities like Chicago, Detroit and Louisville are at risk. However, the chance of a power outage is less likely than that compared to the Delmarva area. The plain fact is, power will go down across the Northeast. This power will be out for over a day, possibly up to a week in the main impact zone, where Sandy will make landfall.

In our analysis of a threat to life and property, the coastal areas all along the Northeast and Mid Atlantic are in the red, or where Life and Property will be threatened. This threat will be maximized from Long Island to Virginia, where Sandy will make landfall and the worst winds will be found. There is a possible threat to life and property further to the west, where winds will not be as intense, but there remains potential for life and property to be at risk from this system.

As far as damaging wind potential goes, there is a chance of damaging winds in the western Ohio Valley and Kentucky into Tennessee. These are the areas where winds will be the least damaging, and should not be the biggest deal on the nation. The bigger deal is found in the Great Lakes and most of the Northeast, where damaging winds are likely. I outlined the Lake Michigan coastline, as winds over 60 MPH are likely on the water. In the Northeast, winds rivaling 75 MPH are likely, especially near the coast. For areas right along the coast, including Long island and New Jersey, I outlined an 'Extreme Winds' area, where I expect winds to flirt with 100 MPH. As outrageous as it sounds, this system has SUSTAINED winds close to 100 MPH, to gusts to the triple digit benchmark is definitely within the realm of possibility.

This is dangerous. If you haven't evacuated and you were ordered to, your life is at risk. Those who stay behind and are near the landfall zone are facing a very serious and catastrophic event, where lives are definitely under the gun.


Shelter in Place Warning - Louisville, KY



Sunday, October 28, 2012

Superstorm Sandy 9:00 PM CT Update (10/28/12)

Latest water vapor analysis of Sandy shows that an eye is still present, although sustained winds put Sandy at the bare minimum 75 MPH hurricane criteria.

The center of Sandy is pretty much on track with the NHC at this time, although I may be seeing a slight wobble to the east of that forecast point, hence the red circle to the east of the track. I don't anticipate this slight wobble to have a significant effect on eventual landfall- a few miles north might be a consequence of this wobble, but that's about it.

500mb analysis does show that Sandy may be beginning to take on a negative tilt, a consequence of Sandy merging with a second system that will provide the base for this decade's first (and hopefully last) superstorm. This will be significant and lives will be threatened. Here's some words of wisdom from the NWS Mt. Holly office:

My afternoon thoughts still stand, and here's the overall graphic from the afternoon.


Mandatory Evacuations - 10/28/12

The following areas are under Mandatory Evacuation orders:

-Islands from Sandy Hook to Cape May
-Areas east of Watson's Creek

-East Haven

-Low-lying coastal areas in the five boroughs

-Sussex county
-New Castle county
-Kent county

-Ocean City

If you are in a mandatory evacuation area, it is advised you heed these warnings and evacuate. Personally, this is ver dangerous and I would evacuate if I were in a mandatory evacuation zone.


State of Emergency Declarations - 10/28/12

The following states are under States of Emergency:

-MAINE (limited state of emergency)

If you are under a state of emergency, prepare for a weather event that could put your property or life in danger. Take all necessary precautions to ensure your safety. If evacuation is recommended, it is advised you heed all government warnings to keep yourself safe. Do not waste time or take chances- this event has the potential to damage property and threaten lives.


Historic Superstorm/Sandy Full Discussion (10/28/12)

"This is unlike any storm I have witnessed in the last several years."

Hurricane Sandy is expected to merge with an incoming disturbance currently progressing east across the nation. As this merge occurs, the now-singular storm system will rapidly strengthen and pose life-threatening conditions to much of the nation's population. Let's break it down.

Model guidance suggests a consensus has formed as far as where Sandy will make landfall. The majority of models used in today's latest 12z suite are saying a landfall on the tip of south New Jersey and in the Delmarva area is likely. Considering this consensus has been holding for quite a while now, I have faith in it and believe this is a likely scenario.

Rainfall will be a big problem, especially right along the coast. In much of the northeast quadrant of the US, I am anticipating under an inch of rain with isolated spots breaking that 1 inch barrier. In the Northeast and Mid-Atlantic, however, 1-2 inches is likely. But it doesn't stop there. The Mid-Atlantic as a whole should surpass the 2 inch mark, and coastal areas in or near the Delmarva region could get as high as 8 inch totals. The real problem comes at the point of landfall, where I believe over 8 inches of rain is likely. Unfortunately, this will lead to flash flooding that will stick around for a while. Because the storm will be pushing water inland, the flooded areas will not be able to get the water out until the storm has moved further inland, a feat that should take a day or two. Then, only time will tell how long flooded neighborhoods will take to be dried out.

This event will have a snowy side as well. As this superstorm moves inland, cold air will be pulled south from Canada in response to such a strong storm. This cold air will sweep into the southwestern flank of the system and penetrate into the heaviest precipitation areas. This will lead to chances of snow across parts of the Ohio Valley and Mid-Atlantic. However, a significant snowfall is likely in the mountainous regions, where some models are showing over 2 feet of snow!! Personally, I believe snow on the order of 6-18 inches is likely, but some spots could break that 2 foot mark.

Our Exclusive Impact Map shows a High Impact event will unfold across the Mid Atlantic and coastal areas of the Northeast, as the very strong system, combined with storm surge makes for a life threatening event in the pink areas. Enhanced Impact areas have been marked across much of the Northeast and Mid-Atlantic as well, where slightly lesser effects of this superstorm will be felt. However, don't let your guard down- this is quite an unpredictable storm.

State of emergencies have been declared, and transportation systems are shutting down. You need to be evacuated if a mandatory evacuation is given. For those of you thinking 'This is just a strong Nor'easter', you are wrong. This is the closest thing to the 1991 Perfect Storm we have seen since 1991. This isn't a time to take chances. The effects will be big and bad, and lives will be at risk.


Saturday, October 27, 2012

Mandatory Evacuations - 10/27/12

The following regions are under mandatory evacuations:

Islands from Sandy Hook to Cape May
Areas east of Watson's Creek


If you are under a mandatory evacuation order, LEAVE AS SOON AS POSSIBLE! This is a serious situation at hand and will threaten lives and property.


State of Emergency Declarations - 10/27/12

The following states are under a state of emergency:

-MAINE (limited state of emergency)

If you are under a state of emergency, you are advised to prepare for a property-threatening and life-threatening event. This is SERIOUS!! Monitor all information given by your local and statewide authorities.


Hurricane Sandy Discussion (10/27/12)

Life-Threatening Storm Heading For East Coast...

Hurricane Sandy is heading for the East Coast in an event what will likely be one for the record books.

Model track guidance and intensity guidance indicate fluctuating strength in the future and a well-built consensus that landfall could occur just south of the southern New Jersey border.

Sandy is fluctuating in strength at this hour as she moves generally north towards the Mid Atlantic. As Sandy moves north, she will be sucked in to another storm system emerging from the Midwest. As these two combine, a situation scarily similar to the 1991 Perfect Storm will emerge.

The combined storms will then move onshore in a feat accomplished by a very small percentage of storms.

High storm surge and extreme rainfall will hit much of the Northeast. Model runs from today show over 2 feet of rain in VERY ISOLATED areas. Nevertheless, this storm surge and extreme rains will lead to quick and sustained flooding in many areas. Long Island could be flooded, although that is yet to be determined.

High winds, possibly exceeding hurricane force status, will bring down trees and pose a serious threat to property and life. Roof damage and overall structural damage is widely expected.

Snow, up to 12 inches, will strike the Appalachians. Higher totals would not surprise me. Because of the Austen's high winds, whiteout conditions would not surprise me.

This is it. If you live along the New Jersey/New York/Delmarva coastal regions, you need to prepare for a real threat to life and property. This isn't your usual system- this will be much worse.

Next week, I'll have an article out examining the potential for this storm to be included in the Lezak Recurring Cycle (LRC).


Friday, October 26, 2012

Hurricane Sandy 11:00 PM Update (10/26/12)

Hurricane Sandy is now on track to hit just south of New Jersey in an event that will prove historic for the region.

Sandy is likely to hit early in the workweek, which may catch many people off guard. Model guidance suggests that this storm may end up lingering around the region, which would provoke sustained flash flooding in the region.

Below, you see the model consensus from the 12z model suite, as well as the 84 hour forecast on the new 0z NAM. On the bottom right, you can see total precipitation that is expressed in values surpassing 100. You can determine the inch value by multiplying the shown value by 0.01 and you can see the total inches of rainfall.

This is getting dangerous. I cannot stress this enough- PREPARE NOW AND EVACUATE IF NECESSARY!!

I will have a morning update tomorrow.


State Of Emergency Declarations - 10/26/12

The following states have declared states of emergency in advance of Hurricane Sandy's arrival:


Residents of these states are advised to prepare for a life-threatening event. Stock up and prepare now for supplies that would enable you to survive at least 3 days without any power.


Hurricane Sandy 4:45 PM Update 10/26/12

Sandy remains a hurricane at this hour, although she has weakened since yesterday. Models indicate fluctuations in strength will continue for the next several hours before a more sustained weakening of Sandy occurs.

I made a new Impact Scale below, detailing my latest thoughts. I did this scale on short notice, and had to do this away from my computer, so it does look a bit mediocre. Here's the breakdown.

Breezy conditions with precipitation possible. A nuisance event.

Windy, small twigs and unsecured objects may blow around. Heavier precipitation is observed. Situation similar to a summer thunderstorm event.

Very windy. Large branches may break off and property damage may occur. Roofing may become damaged. Unstable structures may collapse. Heavy precipitation may cause sustained minor/moderate flooding.

Extreme winds and precipitation. Sturdy structures at risk of severe damage. Entire trees at risk for severe damage. Sustained flash flooding occurs. Life and property threatened.

Models suggest that Sandy will make landfall near the coastal part of Pennsylvania. Regardless of landfall location, THIS WILL BE BIG. Be prepared for long lasting power outages and a threat to life and property. Be able to sustain yourself for at least 3 days without power.

Next update: Between 7-10 PM CT, most likely in the 8:00 PM CT hour.


Hurricane Sandy 2:00 PM Update (10/26/12)

My thoughts from yesterday afternoon still stand: Major Impact situation is unfolding across the coastal regions of the Northeast, where, depending on the strength of Sandy's landfall, winds could surpass hurricane strength.

Here's a region-by-region breakdown for the Northeast:

COASTAL REGIONS (Including Long Island and similar areas)

Winds will likely severely damage trees and property along the coast. Consistent rain will provide a base for SUSTAINED flash flooding. Because land will be covered by water, winds will be enhanced slightly, as winds go faster over water.

INLAND REGIONS (State College, PA and similar regions)

Lesser wind effects will strike, but flooding and consistent, sustained power outages will strike. Trees, houses and other property could be damaged. Life may be threatened.

If you are in the Northeast, you will want to stock up on batteries, flashlights and non-perishable foods and drinks that, if necessary, could sustain you for up to 7 days.



Hurricane Sandy 9:30 AM Update (10/26/12)

Global and regional models depicted below show that a consensus has still not yet been reached. However, the general idea of a Northeast landfall appears set in stone.

Prepare now. I expect widespread power outages, heavy thunderstorms, flash flooding, SUSTAINED flooding, and tree damage. This, in turn, will cause property damage and a serious threat to life.

-Buy batteries and a battery powered radio. This can be used to stay up to date on the latest information.
-Buy food that you can eat in a 7 day period. You will want this in the event a sustained power outage occurs.
-Keep tabs on family members, the elderly, and the disabled.

This will be a dangerous storm. Prepare now to stay as safe as possible.


Thursday, October 25, 2012

Will Sandy Be A Repeat of the 1991 'Perfect Storm'?

Many in the weather world are asking or being asked if Sandy will turn out to be a repeat of the 1991 Perfect Storm that brought chaos to the entire Northeast. Let's see what similarities they have.

SIMILARITY: Both events involve merging storms.
Both the 1991 Perfect Storm and Hurricane Sandy will/did involve the merging of storm systems. Sandy looks like it will merge with a system that is currently bringing cold air to the Midwest and Plains. This merging will bring Sandy inland.

DIFFERENCE: The number of merging storms is different.
Sandy will merge with one other system. The 1991 Perfect Storm managed to hoard two other systems for itself. In other words, Sandy will have less energy to deal with.

SIMILARITY: Both of these events will have tropical origins.
Sandy is currently a Category 2 hurricane, and will still be tropical before it merges with the other system. Hurricane Grace in 1991 was also a Category 2 hurricane in the northern Atlantic that eventually merged with two other systems.

DIFFERENCE: Hurricane Sandy has much lower pressure.
Hurricane Sandy has pressures as low as a major hurricane (Category 3+), while Grace was a short-lived hurricane. Sandy is stronger, Grace was technically weaker.

SIMILARITY: Both occurred in October.
As eerie as this is, yes, both Grace and Sandy are/were active in late October. What makes this story even eerier is how Sandy should make its landfall on the Northeast on October 30- the same day in 1991 that Grace was absorbed by another system, when the Perfect Storm technically began.

DIFFERENCE: Sandy originated in the Caribbean.
There's a major difference here. Hurricane Sandy originated in the heart of the Caribbean, home to moisture as abundant as water in the Pacific Ocean. Hurricane Grace began in the ocean to the far east of Florida, in waters not nearly as favorable as Sandy.

In short, Sandy and Grace were entirely different, and will end up entirely different. While both tropical and post-tropical systems have their similarities, there's a reason why it was named the Perfect Storm- because it almost never happens. Sandy will be a close rival to the Perfect Storm's make-up, but effects and overall composure of the two are pretty far apart.


Hurricane Sandy Full Discussion (10/25/12)

Hurricane Sandy is currently a Category 2 hurricane that is located to the east of Florida at this hour. Satellite imagery indicates that Sandy is a very large storm with a very packed center. However, the southern flank of the system is fairly dry, and I would want to see more enhanced convection in that area to make sure the system sustains itself.

The National Hurricane Center, or NHC, has Sandy moving on a wobbly north track with an eventual curve to the northeast. However, as Sandy moves up the coast, a disturbance located in the eastern North America will drag the system in, causing the two to merge. Because of this merge, Sandy will be directed to the northwest and retrograde (storms moving west in the Northern Hemisphere) into the East Coast, making landfall as a post tropical system.

Models remain fairly confused with this system, although there is a general consensus for Sandy to move in the direction that the National Hurricane Center has Sandy going. There is potential for post-tropical cyclone Tony to grab Sandy and pull her out to sea, but I don't think this will happen and therefore prefer to side with the model guidance of a landfall on the East Coast. Due to the spread in the models when the system makes landfall, things are still a bit unsure as far as who could get snow and who could get the worst winds, but I have put out my best guess at the end of this post.

Rainfall will be a big concern with this system. The Hydrometeorological Prediction Center, or HPC, is indicating that many areas along the East Coast could get a healthy dose of several inches of rain. The heaviest rains look to be out to sea, where amounts in excess of 7 inches are possible as indicated on the above graphic.

The areas most at risk for snowfall include the Appalachians and part of the Ohio Valley, where the latest ECMWF and GFS have indicated the best chances for snowfall are centered. This risk of snow is moreso centered over the Appalachians, with the Ohio Valley thrown in there with more uncertainty than confidence. Because of the cold air being pulled south by Sandy, the lake effect snow machine should start going over the Michigan and Indiana sides of Lake Michigan. The Upper part of Michigan will also get in on some lake effect snow action.

Winds will be howling with Sandy. As she comes ashore, windy conditions can be expected across much of the Northeast, Ohio Valley and Mid Atlantic. The trouble begins in the Northeast, where some of the larger branches may break as Sandy roars in. Coastal cities in New York and Pennsylvania will suffer the worst winds, as offshore winds come on land and worsen the wind crisis. Entire trees will be threatened by these winds.

On The Weather Centre's Exclusive Impact Scale, I believe that only the Northeast and Mid Atlantic stand a chance at some enhanced impacts or major impacts on this scale, meaning property will be at risk and travel is likely to be disrupted. In areas immediately along shore, there will be 'Major Impacts', meaning significant travel disruptions and overall service disruptions are expected. Life and property will be at risk, mainly from winds and possible severe weather.


This storm will be a doozy. If I lived in the 'Major Impacts' area, I would want to stock up at the supermarket for supplies, as power is more than likely going to fail in at least some of the 'Enhanced Impacts' zone. Also, if you have any old or ailing trees in your neighborhood, keep an eye on them. Make sure your property is not in harms way, as trees of all ages may be damaged. Keep tabs on the elderly, those with disabilities, and those who, for some reason, need electricity in their lives (i.e. medical, for pets, etc.), as these people will be most prone to bearing the brunt of the storm's effects.


Wednesday, October 24, 2012

Hurricane Sandy Staring Down East Coast

It should be noted that some information posted here is from yesterday's Sandy update. I repost it only because the information is still valid.

Tropical Storm Sandy has strengthened to a Category 1 hurricane as she moves a steady northbound track at this hour. Sandy has prompted hurricane warnings to be issued for much of the western Caribbean, with Florida also getting into the action. A tropical storm warning is in effect for the eastern coast of Florida, with a tropical storm watch surrounding that warning. With all the controversy swirling around Sandy, I still maintain my case that Sandy will pose a threat to the East Coast, and here's why:

The first thing we must examine is teleconnections. Above is a multi-model display of the 0z models and ensembles' predictions of the North Atlantic Oscillation. The North Atlantic Oscillation, or NAO, has two phases: positive and negative. In the negative phase, a colder and stormier pattern is encouraged over the East US as the jet stream dips south. In the positive phase, warm conditions can be found in the East.

Models are forecasting the NAO to stay well in negative territory, possibly well into November, but that's another story. The key piece is that the NAO will be extremely negative from now until October 27. Because teleconnections observations and their effects are delayed (the atmosphere doesn't work that fast), we want a good 3 day lag of negative NAO values before the storm strikes to show that the NAO would support such a possibility of an East Coast threat. Looking at the NAO forecasts, there is a good consensus on such a negative period through Halloween, which will enable the jet stream to dip in a negative NAO pattern. This provides a base for a theory on an East Coast threat.

Shown above are the ECMWF Ensembles on top and the GFS Ensembles on the bottom. Both are from today's 12z model suite. As you can see, both indicate that a strong system will hit the Mid Atlantic in the days leading up to Halloween. The two ensemble sets are pretty similar in forecasts- both have a strong storm crashing into the Mid Atlantic, and this situation would indeed pull down very cold air as the GFS ensembles depict on the lower image.

I believe that an ensemble set always triumphs over a single model. Why? Well, imagine the ECMWF model. It's a great model, very reliable, a very good model overall. Now imagine that same ECMWF model, but now there's 52 of them, combined into one overall forecast. It sounds too good to be true, almost like a sure-fire forecast (for the record, that's nearly impossible, no matter the model). That sums up what the ECMWF ensemble system is. The same goes for how the GFS Ensemble system works.

As the storm moves north (likely influenced by both the strong cyclone to the northeast and the advancing disturbance to the west), it has two options, which is the key player that is confusing the models. Here is a breakdown of each option.

Option 1: The storm moves north and is coaxed east by the strong disturbance located to the northeast in the image above. The storm keeps moving northeast and does not affect the US mainland.

Option 2: The storm moves north, but is more influenced by the disturbance in the Ohio Valley. The Fujiwhara Effect comes into play, and Sandy cycles to the west to orbit with the incoming disturbance over the Ohio Valley. This cycling persuades Sandy to move towards the US and make landfall. Personally, at this point in time, I am favoring Option 2.

I've run over the model forecasts and weather theories to give my first (but certainly not last) forecast on Sandy. Keep in mind that she will be EXTRATROPICAL (not a hurricane, but a strong coastal storm like the ones seen in winter). However, this does not mean that the tornado threat will be nil- such a post-tropical cyclone can definitely produce some tornadic activity.

DISCLAIMER: These are my own personal thoughts and are subject to major change in the next several days.
DO NOT use this information in place of official government weather information.

Model Ensembles Prefer East Coast Landfall

Above, you see the GFS Ensembles on top and the ECMWF Ensembles on bottom, forecasting MSLP values in the Atlantic. They are both valid for 7 days from now.

The ECMWF Ensembles combine to believe that a strong system will make landfall in the Mid-Atlantic, with heavy winds and rain following along. I do not doubt the presence of some snow in the Ohio Valley from this system as well if the ensembles give enough cold air to the west of the original landfall.

The GFS Ensembles are even stronger and also hit the Northeast with Sandy at a strength in the 980's, indicating that the system looks to be pretty strong. It should be noted that for both sets of ensembles, some members are stronger than this, and some members are weaker than the forecasts above. This is a mean (average) of all of the ensembles within the GFS' base or the ECMWF's base.

I show you these forecasts because the models themselves may as well be as good as a life raft in the desert- sometimes it's practical (for shelter), sometimes it's not (there are no oceans in the desert). I think it's time to take a few steps back and see what the ensembles have to offer, because they are the best bet at this long range forecasting of a tropical cyclone.


Tuesday, October 23, 2012

Long Range Lookout: ECMWF Late Fall-Early Winter 2012 Forecast

This is the ECMWF's Late Fall-Early Winter 2012 Forecast as interpreted by The Weather Centre. I will not provide the actual image out of copyright concerns.

The ECMWF's climate model is projecting a big swath of the Plains, Midwest and Rockies to be in a slightly cooler than normal state in this timeframe. No frigid temperature anomalies are expected to arise, although such a potential would be maximized in the Southwest states (New Mexico into Arizona). The Northeast and Southwest are portrayed as areas with above normal temperatures, the Northeast bearing the warmer brunt of the two.

As for precipitation, the ECMWF cites a below normal precipitation area across the meeting ground between the Northwest and Southwest. A chance of below normal precipitation is forecasted across parts of the Gulf Coast, but other than that, the ECMWF is relatively not concerned with the rest of the nation as far as precipitation anomalies go.

Keep in mind these forecasts are from one model of at least a few dozen- one fish in a never-ending sea, so to speak. So don't lose all hope just because one model says little precipitation is forecasted.


Sandy Likely To Threaten Mid Atlantic

The following is my own personal thoughts on Sandy and is provided as an advice article. I am not responsible for whatever actions you take in response to this article, and do not endorse or reject doing any activity directly in response to the following information.


I now believe Tropical Storm Sandy has real potential to affect the East Coast, whether it be from a tropical viewpoint or on the snowy side. This is indeed a pretty bold statement, so let's decipher why I think this could get serious.

The first thing we must examine is teleconnections. Above is a multi-model display of the 0z models and ensembles' predictions of the North Atlantic Oscillation. The North Atlantic Oscillation, or NAO, has two phases: positive and negative. In the negative phase, a colder and stormier pattern is encouraged over the East US as the jet stream dips south. In the positive phase, warm conditions can be found in the East.

Models are forecasting the NAO to stay well in negative territory, possibly well into November, but that's another story. The key piece is that the NAO will be extremely negative from now until October 27. Because teleconnections observations and their effects are delayed (the atmosphere doesn't work that fast), we want a good 3 day lag of negative NAO values before the storm strikes to show that the NAO would support such a possibility of an East Coast threat. Looking at the NAO forecasts, there is a good consensus on such a negative period through Halloween, which will enable the jet stream to dip in a negative NAO pattern. This provides a base for a theory on an East Coast threat.

The second item, potentially of much more importance, is something called the Fujiwhara Effect. The Fujiwhara Effect is named after Sakuhei Fujiwhara, and deals with interactions between two cyclones in close proximity. When I say 'cyclones', I mean a disturbance, tropical or non-tropical. The Fujiwhara Effect states that, when two cyclones are in close proximity, they will begin to orbit each other in a cyclonic flow (counterclockwise). To build off of this theory, let's look at the latest ECMWF forecast below.

This is the ECMWF forecast for hour 96, showing 850mb vorticity, 500mb heights, and MSLP readings. These three combine to give a fairly accurate depiction of where disturbances and high pressure systems are located. 96 hours (4 days) away from now, we see a very strong Sandy sneaking by Florida. However, notice the reds and oranges in the Ohio Valley and Northeast. That is a disturbance. We can now apply the Fujiwhara effect.

As the storm moves north (likely influenced by both the strong cyclone to the northeast and the advancing disturbance to the west), it has two options, which is the key player that is confusing the models. Here is a breakdown of each option.

Option 1: The storm moves north and is coaxed east by the strong disturbance located to the northeast in the image above. The storm keeps moving northeast and does not affect the US mainland.

Option 2: The storm moves north, but is more influenced by the disturbance in the Ohio Valley. The Fujiwhara Effect comes into play, and Sandy cycles to the west to orbit with the incoming disturbance over the Ohio Valley. This cycling persuades Sandy to move towards the US and make landfall.

If we look at the 12z ensembles forecasts for Sandy, we can see that they are showing both potential options happening. However, one can see that the edge is given to Option 2, where Sandy makes landfall on the Mid Atlantic/Northeast. Such a situation could be dangerous- similar to how Nor'easters 'bomb out' (rapidly strengthen) in the wintertime as they go up the East Coast, Sandy could very well do the same, bringing a tropical hurricane to an extratropical (not a hurricane) monster that would likely bring rain, snow, and a severe weather threat to much of the East US.

The ECMWF Ensembles (very reliable in my eyes) go as far as to say Sandy will merge with the Ohio Valley disturbance mentioned above and make landfall. Such a merge is called 'phasing', meaning two storms coming together into one. Again, the storms would be attracted to each other and Sandy would be persuaded to move west and retrograde (storms moving west in the North Hemisphere) into the US.

I honestly don't want to even discuss snowfall amounts, but here's some 'eye candy' for you winter weather lovers. This is off the 0z ECMWF and is 240 hour (10 day) snowfall total. This is from AccuWeather Pro and should be referenced as such if you are going to use this image. (Know that the data is not from Accuweather (snowfall forecast), the layout of the image is (color scheme, outline of image, etc.))

In summary: I believe that the East Coast has a threat on their hands. How great this threat actually is has yet to be determined. However, I advise all East Coast residents to keep a close eye on this system. If I lived in the Mid Atlantic, I might want to just keep an eye out at the moment, maybe make sure you have necessary supplies in the event of any evacuation at any time, not just for this event.