Long Range Snow Possibilities Arising

Models are indicating very long range snow potentials, which can be a precursor to a possible snow event in the future.

While long range forecasts rarely verify, they can offer hints on what eventually happens. For example, if a model were to show a massive hurricane devastating New York 2 weeks out, you wouldn't believe it. Neither would I. However, things like that alert forecasters to keep a general eye out on that timeframe for some form of tropical activity in the general Atlantic Ocean.

If we apply that rule to this situation, I can see the potential for a snow possibility as a massive cool down is predicted about 2 weeks out. I choose to believe the long range cool down theory as the ensembles are trending with it, something taken much more seriously than a single model's forecast.

In short, I could see some part of the nation getting a little of the white stuff. I doubt it will be significant, and probably would hit farther north. Either way, exciting times appear ahead for the central and eastern US!

Andrew

Blowing Dust Causing Problems in Kansas

A body of blowing dust is progressing across the southern Plains at this hour on the edge of a very strong extratropical system in the Midwest.

Satellite imagery shows a swath of blowing dust currently hitting the Plains states, with Kansas and Oklahoma getting the worst of the dust. Many people underestimate the issues blowing dust can cause, so let's review what problems can arise from blowing dust, as small as some may be.

•Asthma is aggravated.
•Elderly people an children's respiratory systems may struggle to handle the foreign contaminants (dust particles)
•Damage to machinery that takes in air from the atmosphere- dust can enter the machine and cause it to malfunction.

All people are advised to stay inside, no matter your presence or lack of medical conditions related to the respiratory system until this passes by, which could take several hours.

Andrew

Tropical Corner: Late Season Burst Possible In Atlantic

This is the MSLP forecast from the 6z GFS at hour 384- the longest this model goes to. That's roughly 14+ days out. What you are seeing is a pair of tropical cyclones going down two different paths. The one on the left would most likely take a path similar to Isaac, while the one on the right would go out to sea. While this forecast has the slimmest of chances to verify, the idea that this is even a possibility to the GFS is quite alarming. In today's Tropical Corner, we'll investigate why a late season tropical burst of activity is possible.

This is the 500mb height anomaly chart for hour 168, meaning this forecast is valid 168 hours from now. The GFS Ensembles that made this chart are showing a deep trough in the West and a strong ridge in the East, typical of a strong negative PNA pattern. It is common for tropical systems to gain an advantage when a pattern like this is present, as the ridge in the East diverts the jet stream north. Because the jet stream is diverted north, the upper level winds in the Atlantic are fairly low, enabling thunderstorms to strengthen and thus enhance potential for tropical cyclone formation.

I find a few problems with the GFS solution, and even the ECMWF, which is also showing tropical troubles by the end of the next 10 days. This ridge should die off by the time 8 days is up from now. After that 8 days, the negative PNA pattern will collapse and the trough will progress east into the central and eastern parts of the nation. This trough's movement east will push the jet stream south and thus drop tropical cyclone formation potential over the Caribbean and Atlantic areas. The timing is not matching up.

Climate models are projecting unfavorable conditions for tropical cyclone formation as well, with the CFS long range model hinting at strengthening upper level winds in the 10-15 day time frame, which would drastically hurt tropical cyclone formation chances.

Andrew

Cold Outbreak Rounding Out Next 10 Days; Cool Halloween Ahead?

The 12z ECMWF is slamming down on the nation with an absolutely brutal cold snap coming to the northern Plains an eventually the central and eastern parts of the nation in the next 10 days.

Above are two images dealing with the 850mb level, commonly used to identify areas of warm and cold air. The ECWMF is taking a major storm in Canada and having it sweep brutally cold sir south into the US. The bottom image is 850mb temperature anomalies, of which are bottoming out as low as 19 degrees below normal!

Many locations will be at risk for some flakes flying. If there will be any accumulation remains to be determined, but this cold snap could lead the way for a bang to start November in the East- and possibly a very chilly Halloween.

Andrew

Warming Temperatures Accompany Next Week

This temperature graph from the GFS Ensembles is showing a very defined warm up over the Plains and Midwest, among other regions, going into the beginning of the upcoming work week. Let's take a look into what this is all about.

This is a picture of the average temperature anomalies that the 12z GFS Ensembles are showing for Monday, October 22nd. The ensembles are displaying temperature anomalies as much as 12 to 15 degrees above normal- quite a feat for late fall. This warm up comes as a deep negative PNA signature takes over. When you get that cold over western Canada and the Northwest US, such a stormy and cold pattern in those regions commonly leads to a warm up in the central and eastern regions of the States.

This warm up looks to be fairly progressive, with positive temperature anomalies lasting only a few days before another big release of cold air hits the nation.

It looks like the weekend and beginning of the upcoming work week may allow the heavy jackets to go into a short hibernation!

Andrew