Saturday, June 18, 2011

June 18- Tropical Cyclone Discussion- Evening Update, East Pacific Ocean

This is only an update.

This system has not changed in organization and retains a 60% chance for development over the next 2 days.
The only difference from this morning is a greatly increased prospect for strength into hurricane strength.

June 18- Tornado Warning: Carson, ND


THE NATIONAL WEATHER SERVICE IN BISMARCK HAS ISSUED A

* TORNADO WARNING FOR...
  NORTH CENTRAL GRANT COUNTY IN SOUTH CENTRAL NORTH DAKOTA...
  CENTRAL MORTON COUNTY IN SOUTH CENTRAL NORTH DAKOTA...

* UNTIL 630 PM CDT/530 PM MDT/

* AT 500 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO. THIS DANGEROUS
  STORM WAS LOCATED 7 MILES NORTH OF CARSON...OR 41 MILES SOUTHWEST
  OF BISMARCK...AND MOVING NORTHEAST AT 25 MPH.

* LOCATIONS IMPACTED INCLUDE...
  ALMONT.

June 18- Tornado Warning: Cheyenne Wells, CO


THE NATIONAL WEATHER SERVICE IN GOODLAND HAS ISSUED A

* TORNADO WARNING FOR...
  EASTERN CHEYENNE COUNTY IN EAST CENTRAL COLORADO...

* UNTIL 515 PM MDT

* AT 424 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO. THIS DANGEROUS
  STORM WAS LOCATED 6 MILES WEST OF FIRSTVIEW...AND WAS MOVING
  SOUTHEAST AT 35 MPH.

* LOCATIONS IMPACTED INCLUDE...
  FIRSTVIEW...CHEYENNE WELLS AND ARAPAHOE.

THIS INCLUDES HIGHWAY 385 BETWEEN MILE MARKERS 136 AND 162.

June 18- KSGF Sounding indicative of dangerous atmosphere

I'll just say this right off the bat, this is a very hard map to understand, and I will explain everything that needs to be explained.

This sounding from Springfield, Missouri indicates that the atmosphere is very unstable and dangerous right now.
CAPE levels are above 5000 j/kg. To give you a scope of how dangerously unstable that is, the threshold for severe storms begins at 2000 j/kg of CAPE. So 5000 j/kg could easily produce dangerous thunderstorms.
The lifted index is at -12, which is considered rare for atmospheric conditions. The lower the LI, the more unstable.
The SigSevere parameter, which can indicate if significant severe weather will occur (F2+ tornadoes, very large hail, extreme winds), usually begins at 20,000. Currently, Springfield, MO is reporting a SigSevere amount at 84,000 units.

Luckily, the jet stream at 300 millibars is only at 40 knots, which isn't too impressive, but is still a fair amount. The lower level jet stream is the same speed.
Hodographs (data showing the atmosphere rotating as it moves up in the atmosphere levels) are somewhat interesting at lower levels, suggesting low level rotation may be possible with storms, but upper level rotation is limited and overall not too organized.

Now, the only question is if storms will occur there.
We will see as we go on into the night.

June 18- Tornado Warning: Near Flagler, CO



* TORNADO WARNING FOR...
  NORTHWESTERN CHEYENNE COUNTY IN EAST CENTRAL COLORADO...
  SOUTHWESTERN KIT CARSON COUNTY IN EAST CENTRAL COLORADO...

* UNTIL 400 PM MDT

* AT 314 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO. THIS DANGEROUS
  STORM WAS LOCATED 11 MILES NORTH OF BOYERO...OR 16 MILES SOUTHWEST
  OF FLAGLER...AND WAS MOVING EAST AT 30 MPH.

  IN ADDITION TO THE TORNADO...THIS STORM IS CAPABLE OF PRODUCING
  DESTRUCTIVE HAIL UP TO HEN EGG SIZE.

* LOCATIONS IMPACTED INCLUDE...
  MAINLY RURAL AREAS OF NORTHWESTERN CHEYENNE AND SOUTHWESTERN KIT
  CARSON COUNTIES.

June 18- Tornado Warning: Hugo, CO


THE NATIONAL WEATHER SERVICE IN DENVER HAS ISSUED A

* TORNADO WARNING FOR...
  EAST CENTRAL LINCOLN COUNTY IN EAST CENTRAL COLORADO

* UNTIL 315 PM MDT

* AT 246 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO NEAR HUGO...OR
  15 MILES SOUTHEAST OF LIMON. THIS STORM WAS MOVING EAST AT 20 MPH.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO HUGO.

June 18- Tornado Warning (Tornado Spotted): Benton, Tennessee



...A TORNADO WARNING REMAINS IN EFFECT UNTIL 500 PM EDT FOR POLK
COUNTY...

AT 438 PM EDT...A TORNADO WAS REPORTED.  THIS TORNADO WAS LOCATED
NEAR ARCHVILLE...OR 10 MILES EAST OF BENTON...MOVING EAST AT 30 MPH.

THE TORNADO WILL BE NEAR...
  DUCKTOWN AROUND 455 PM EDT.

OTHER LOCATIONS AFFECTED BY THIS SEVERE THUNDERSTORM INCLUDE
TURTLETOWN.

June 18- Tropical Cyclone Discussion- East Pacific Ocean

There is a 60% chance for tropical cyclone formation for a system to the west of extreme south Mexico. The system in mention has not become better organized over last night. However, there remains a window of opportunity in which this system can become a tropical cyclone (depression, storm, etc.)
Infrared satellite imagery is messy right now. There is a cluster of strong storms to the west of the low pressure system. This may be interfering with development of this system. There is currently no defined center of this system, with no circulation evident.
This system may actually be overhyped, as I am not seeing this system developing with how horribly disorganized this system is right now, as well as the cluster of storms to the west of the low pressure system.
Current surface analysis by the OPC doesn't help this system's case, but it does infer that potentially the cluster of storms could be actually related to the low pressure system. However, it's really hard to see right now because of how messy the system is.
There's a tropical wave moving onshore to Central America. Showers and storms are associated with this wave, and I will check up on this wave once and a while in case it becomes eligible for development when it crosses into the East Pacific Ocean.
Models have dropped off this solution of even making this system into a tropical cyclone. Either way, the models that do participate in this run keep it very close to land, with a couple models even making a landfall. I'm not going to rely on these models closely, because the models are sending mixed messages.
Even more models dropped off the intensity forecasts than the tracks of this storm. Maximum strength reaches tropical storm status, however even that may not happen.

I will watch this situation closely and issue more forecasts as necessary.

June 18- Severe Weather Discussion

There is a slight risk of severe weather for portions of the: Central Plains, Midwest, Southeast. Mainly affected is: The Nation's Midsection.

There is currently a sector of moist and unstable atmospheric conditions in central KY east into KY/TN. However, there are several clusters of showers and storms ongoing in the areas. That will affect the atmospheric conditions into today. Those are specific details that will have to be worked out and will likely become a nowcasting event. (Nowcasting= forecasting as the event is happening)

It looks like moderate to stronger showers and storms will progress from Central Illinois into Central Indiana moving WSW.

The areas to watch for today's severe weather are:
-Central/South IL
-Central/South IN
-East half of Kentucky

This comes as a short range model projects a strong cluster of thunderstorms to come down into Kentucky after battering the first two areas mentioned.

Today's Hail Outlook

Today's Wind Outlook

Today's Tornado Outlook