SEVERE WEATHER THREAT…MODERATE RISK ISSUED…PHFC SYNOPSIS…APR. 17, 2013…ISSUED 11:50 A.M. EDT…WIDEST DISSEMINATION REQUESTED

Good day everyone!

The Storm Prediction Center (SPC) has issued a MODERATE risk are for Severe Thunderstorms today.  From the SPC Outlook:
VALID 171630Z – 181200Z

…THERE IS A MDT RISK OF SVR TSTMS THIS AFTERNOON AND TONIGHT FROM NWRN TX THROUGH CNTRL OK INTO SERN KS AND FAR SWRN MO… 

…THERE IS A SLGT RISK OF SVR TSTMS INTO TONIGHT FROM PORTIONS OF THE SRN PLAINS INTO THE MIDWEST… 

…THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON AND EVENING OVER PARTS OF KY/TN…

FARTHER SWWD ALONG THE FRONT FROM N-CNTRL OK INTO NWRN TX…STRONGER CAPPING IS EXPECTED TO DELAY STORM INITIATION UNTIL LATER THIS AFTERNOON INTO EVENING WITH THE HIGHEST PROBABILITY OF DEVELOPMENT OCCURRING NEAR THE DRYLINE-FRONT TRIPLE POINT. DESPITE AN INITIAL WEAKNESS IN FORECAST HODOGRAPHS IN THE 2.5-4 KM AGL LAYER…THE ENVIRONMENT WILL BE VERY SUPPORTIVE OF INTENSE SUPERCELLS CAPABLE OF VERY LARGE HAIL AND TORNADOES /SOME POTENTIALLY SIGNIFICANT AND LONG-TRACKED/. AN ENHANCED TORNADO THREAT IS EXPECTED TO PERSIST INTO TONIGHT ALONG THE I-44 CORRIDOR OF OK WHERE HODOGRAPHS WILL GROW INCREASINGLY LARGE AND THE BOUNDARY LAYER WILL REMAIN VERY MOIST AND MODERATELY UNSTABLE.

SPC DAY 1 CONVECTIVE OUTLOOK

SPC TORNADO PROBABILITY MAP

Probability of a tornado within 25 miles of a point.
Hatched Area: 10% or greater probability of EF2 – EF5 tornadoes within 25 miles of a point.

SPC CONVECTIVE WATCHES DISPLAY

SPC MESOSCALE DISCUSSIONS DISPLAY

NWS HAZARDS AND WARNINGS DISPLAY

INTELLICAST NWS DOPPLER RADAR

Analysis of the Outlook indicates there could be an area of focused Tornado activity within the MODERATE risk area.  Analysis of data from F5 Data Severe Weather Software from the NAM-WRF, GFS, NAVGEM indicates the model output is pretty much in good agreement on the strength of SWEAT values, SBCAPE, and a couple of Tornado Risk parameters.  Upon analysis, a tornado threat with a very likely probability of isolated strong tornadoes (EF2-EF5) has a 50% to 70% chance, WITH NEW INFORMATION INDICATING still a possible risk of isolated strong tornadoes… however it is unknown at the moment, whether or not SPC will maintain a MODERATE risk assessment.  Based on new analysis of F5 DATA Software, (GSF, RAP, NAVGEM)  I have updated the following map, regarding the fairly moderate probability of some isolated strong tornadoes.  Bear in mind, THIS DOES NOT MEAN IT WILL HAPPEN, however most of the parameters are there, so I have elected to err on the side of caution.

day1otlk_1300TOR

Based on MLCAPE values reaching 2000-3000 j/kg, and SBCAPE at around 1500-2000, and  the MODERATE risk, this has the potential to possibly become a PDS (Particularly Dangerous Situation) in the hatched tornado probability area.

Residents, especially in the MODERATE risk area should closely monitor NOAA Weather Radio, and local NWS office statements regarding today’s severe weather risk.  As always, please check back here often, as the watches, warnings, Mesoscale maps will update automatically.

Have a safe and blessed day!

T. F. “STORM” WALSH III
GMCS, USCG (ret)
METEOROLOGIST / HURRICANE SPECIALIST
MEMBER WEST CENTRAL FL AMS 
CERTIFIED SKYWARN OFFICIAL STORM SPOTTER (advanced)
CoCoRaHS OBSERVER

Advertisements

About palmharborforecastcenter

I am a Tropical Forecast meteorologist, providing hurricane forecasts during the Atlantic Hurricane Season. I retired from the U.S. Coast Guard in July of 2001. Meteorology became my passion in high school, and I have continued my educational background in meteorology since 1996, when I undertook the study of Tropical Meteorology. While working toward my degree, I had to unexpectedly withdraw from college due to my oldest sons medical reasons. I do however, meet the educational criteria of the AMS to be recognized as a meteorologist. Studies include, but are not limited to the Navy Aerographers Mate course, Naval METOC meteorology course, Meteorology 2010 Sophomore level course while attending St. Petersburg College, Clearwater, FL., Basic Forecasting course for operational meteorologists from Rapid WX, meteorology institute, a four month meteorological internship, and extensive research on numerous meteorological topics such as the MJO, NAO, satellite imagery interpretation, etc. I have been forecasting Tropical Weather (Tropical Storms and Hurricanes) since 1996, with my main client being three different Coast Guard Commands.
This entry was posted in Severe Weather. Bookmark the permalink.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s