ENHANCED SEVERE WEATHER RISK…POSSIBLE STRONG TORNADOES…FORECAST SYNOPSIS…ISSUED APR. 24, 2015…12:10 P.M. EDT

ALL forecasts contained on this site,  are based on my analysis and knowledge of various forecast tools, including information contained in NHC products, and are not copies from any other entity.

 You may click on the graphics for animations, close in views, and current information, as they are linked to their respective sites.

Good day everyone!

A little late due to late model updates.

The Storm Prediction Center (SPC) Norman, OK. has designated 2 separate ENHANCED risk areas of Severe Thunderstorms in the Day 1 Outlook FROM CNTRL TX ENE INTO SRN AR/NRN LA…and OVER PARTS OF CNTRL AND ERN KS…

There is a SLIGHT risk SURROUNDING THE ENHD AREA…FROM KS SSE TO THE WRN GULF CST…

There is a MARGINAL risk FROM NEB SSE TO THE WRN AND CNTRL GULF CST…

I have several graphics to post, but coincide with my analysis and forecast in combination with the SPC outlook text.

SPC DAY 1 CONVECTIVE OUTLOOK, TORNADO PROBABILITY AND HAIL PROBABILITY MAPS
day1otlk_1300

day1probotlk_1300_torn

day1probotlk_1300_hail

Based on the text information in the outlook, and graphics output from the RAP and NAM-WRF models using F5 DATA Severe Weather software, the severe weather event should initiate around early afternoon…3:00 – 4:00 p.m. CDT, and continuing into the evening hours to possibly 10:00 p.m. CDT. 

For the Central Plains area, especially KS, the strongest and best probability of severe weather should occur within the SPC outlook enhanced risk outline.  Model output does not rule out the possibility of some isolated strong tornadoes (EF3 – EF5) occurring with stronger, rotating supercells, or within stronger supercells that may lie within a QLCS.

F5 DATA NAM-WRF BEST SEVERE PROB. (in addition to SPC) day1otlk_1300_.2

Further south over the Southern Plains area, the SPC has expanded the enhanced risk area.  During my pre analysis this morning, model output suggested this.  I had even had the premise that SPC may even include a moderate risk area within the enhanced area, but forecast sounding parameters and indices had weakened somewhat during the 12Z update.  Depending on how the thermodynamics work out, I still believe a slim chance for an upgrade could occur.  This is only my opinion however.

Based on forecast sounding parameters, albeit not shown int he SPC forecast, and against my better judgment, but in line with the forecast parameters per a combination of the RAP and NAM-WRF models, as well as the NOAA SREF model output, I am extending the best severe probability a little further south over Texas. As far as tornado activity, tornadoes should occur within the SPC outlines. 

For KS., closer to the center of the 5% area, and east, some tornadoes could be on the strong and long track side.

Over the Southern Plains area, I have outlined a best tornado probability.  This outline, based on various model output regarding Significant Tornado Parameter indices, indicates some tornadoes over this area may become strong and long tracked.  For simplification, Energy Helicity Index values forecast were 3 – 6 this morning, with the STP (Significant Tornado Parameters ranging 3 – 9.  These indices alone indicate a high probability of strong, long tracked tornado activity.

F5 DATA BEST TORNADO PROB. (in addition to SPC) f5nam.day1tor7pmcdt

SIGNIFICANT TORNADO PARAMETER INDICES CENTRAL_ETA212_TORNADO-MASK_24HR CENTRAL_MESO-NAM212_ATMOS_STP_18HR CENTRAL_MESO-NAM212_ATMOS_STP-NEW_18HR

I have include the dryline forecast, as SPC mentions the dryline could play a significant part today.

DRYLINE FORECAST 4:00 P.M. CDT f5nam.4pmdryline

DRYLINE FORECAST 7:00 P.M. CDT f5nam.7pmdryline

DRYLINE FORECAST 10:00 P.M. CDT f5nam.10pmdryline

Residents in and around the ENHANCED risk areas should monitor NOAA Weather Radio, and local NWS Statements and bulletins throughout the day for any significant changes. PLEASE refer to the following, linked graphics for up to date information.  You will have to click on these for the updates, as the graphics on this page remain static.  SPC will update the DAY 1 OUTLOOK by 12:00 Noon EDT.

SPC CONVECTIVE WATCHES DISPLAY (LINKED)

SPC MESOSCALE DISCUSSIONS DISPLAY (LINKED)

INTELLICAST DOPPLER RADAR ANIMATION (LINKED)

NWS WARNINGS AND HAZARDS DISPLAY (LINKED)

Outlook-category-descriptions

SPC has also designated Severe Weather risks in the DAY2 and DAY 3 Outlooks.  I am not available on weekends until Hurricane Season begins, so please check the SPC site for information regarding severe weather this weekend.

SPC DAY 2 CONVECTIVE OUTLOOK day2probotlk_0600_any

SPC DAY 3 CONVECTIVE OUTLOOK day3prob_0730

Please check out my Preliminary Seasonal Hurricane Outlook published on Apr. 16, 2015

Have a blessed day!

T. F. “STORM” WALSH III GMCS, USCG (ret)
METEOROLOGIST / HURRICANE SPECIALIST / SEVERE WEATHER SPECIALIST MEMBER WEST CENTRAL FLORIDA AMS
CoCoRAHS OBSERVER    

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