SEVERE WEATHER…SLIGHT RISK…FORECAST SYNOPSIS…MAR.15, 2014…ISSUED 1:00 P.M. EDT…PHFC

Good afternoon all!

Just wanted to reiterate:

After some debate as far as a paid subscribe site, I’ve based a price for subscription to the site at $10.00 per month.  IF I have enough folks subscribe, I may be able to go lower on the price.  However, if enough of you fine folks who visit and really rely on me for my hurricane and severe weather forecasts are able to subscribe, this will be my full – time employment..daily.  I should be able to be on site no later than 9:00 a.m., and will run it until around 5:00 – 6:00 p.m. (schedule will depend on whether or not we have anything going on, how much is going on, and, will also have to work around any family crises, and family and self medical appointments).  I will pretty much then be at my desk all day, and checking on situations every 2 – 3 hours.  During Hurricane Season, this will allow me to post a morning and late afternoon, to evening synopsis.  I will also add my cell phone number as my business number, so you may call me ANYTIME within the office operating hours.  As I have said before, I REALLY hate to do this, but if I don’t do something, I will go under, and won’t be able to forecast at all.

Please let me know if $10.00 / month is reasonable for all of you.  I still have to work on getting it all setup, and will send out messages as to where it stands, and when it will switch.  I do not intend to have different prices for different portions of the page…I feel, if you’re going to be “purchasing” the site monthly, I want you to be able to access ALL the information.  I will also be cleaning up the toolbox of links that no longer work, as well as adding new links you may be interested in.  With that said:

The Storm Prediction Center (SPC) Norman, OK has issued a SLIGHT risk of Severe Thunderstorms for:  PORTIONS CENTRAL TX/ARKLATEX TO LOWER DELTA REGION AND MS COAST…

SPC DAY 1 CONVECTIVE OUTLOOK MAP


SPC DAY 1 OUTLOOK TEXT:

…SYNOPSIS…

UPPER-AIR PATTERN WILL BE DOMINATED THIS PERIOD BY HIGH-AMPLITUDE BUT PROGRESSIVE RIDGING…MOVING EWD FROM W COAST…AND LARGE CYCLONIC GYRE COVERING MUCH OF ERN CANADA AND CENTERED OVER HUDSON BAY. E OF THAT RIDGE–TWO SHORTWAVE TROUGHS WILL SERVE AS PRIMARY MID-UPPER INFLUENCES ON CONVECTIVE POTENTIAL DAY-1… 1. SRN-STREAM PERTURBATION NOW EVIDENT IN MOISTURE-CHANNEL IMAGERY OVER ERN NM…FAR W TX AND CHIHUAHUA. THIS TROUGH WILL LOSE AMPLITUDE AS EMBEDDED 500-MB VORTICITY MAX/WEAK CIRCULATION EJECTS ENEWD ACROSS N-CENTRAL TX/EXTREME S-CENTRAL OK AROUND 00Z…REACHING SERN OK/SWRN AR/NE TX BY END OF PERIOD. 2. NRN-STREAM TROUGH CURRENTLY MOVING SEWD ACROSS PORTIONS SRN MT…WRN WY AND ERN UT. THIS FEATURE WILL TURN SSEWD ACROSS SRN ROCKIES AND INTENSIFY CONSIDERABLY BY 12Z…REACHING LOWER-MIDDLE PECOS VALLEY AND PORTIONS N-CENTRAL MEX.

CYCLONIC FLOW ASSOCIATED WITH THESE FEATURES WILL BROADEN ACROSS SRN PLAINS AND NRN MEX…WITH HEIGHT FALLS INTENSIFYING AND SHIFTING SLOWLY EWD ACROSS THESE REGIONS AND NWRN GULF BY END OF PERIOD.

AT SFC…11Z ANALYSIS SHOWED WAVY/QUASISTATIONARY FRONTAL ZONE FROM MO BOOTHEEL REGION WSWWD ACROSS ERN/SWRN OK…NW TX…BETWEEN LBB-MAF…AND OVER SERN NM. WARM FRONTOGENESIS WAS EVIDENT FROM BETWEEN DYS-CDS EWD ACROSS TXK AREA AND SRN AR. BOTH OF THESE BOUNDARIES ARE EXPECTED TO BECOME ILL-DEFINED TODAY AS RETURN FLOW OCCURS AHEAD OF SEPARATE COLD FRONT MOVING SEWD ACROSS CENTRAL HIGH PLAINS…AND PERHAPS MORE IMPORTANTLY…GROWING AREAS OF CLOUDS…PRECIP AND TSTMS OVER TX AND OK RECONFIGURE BOUNDARY-LAYER BAROCLINICITY CONSIDERABLY ON MESOSCALE.

…SRN PLAINS…MORNING THROUGH EVENING… MESSY SCENARIO EVIDENT WITH SCATTERED-NUMEROUS SHOWERS AND TSTMS EXPECTED TO DEVELOP THROUGH REMAINDER MORNING/EARLY-AFTN HOURS ACROSS PORTIONS W-CENTRAL/NW/N-CENTRAL TX AND MUCH OF OK…OFFERING MRGL WIND/HAIL RISK. ADDITIONAL TSTMS SHOULD FORM THROUGH AFTN OVER CENTRAL TX AND MOVE/SPREAD ENEWD….THESE HAVING BETTER-ORGANIZED SVR THREAT. THIS PROCESS WILL OCCUR AS LARGE-SCALE ASCENT ALOFT…IMMEDIATELY PRECEDING MID-UPPER TROUGH…BECOMES INCREASINGLY JUXTAPOSED WITH FAVORABLE LOW-LEVEL THETAE ADVECTION.

 MOISTURE TRANSPORT/ADVECTION ALREADY UNDERWAY ABOVE SFC WILL BE MANIFEST IN PRECONVECTIVE SFC ENVIRONMENT BY NWD SPREAD OF 60S F SFC DEW POINTS NOW IN CENTRAL/S TX TOWARD RED RIVER…AND 50S THAT HAVE REACHED SRN OK. THICK MIDDLE-HIGH CLOUDS WILL PRECLUDE STG SFC DIABATIC HEATING ACROSS MUCH OF THIS AREA…HOWEVER…COMBINATION OF DIFFUSE INSOLATION AND WAA WILL BOOST MLCAPE AND REDUCE MLCINH THROUGHOUT MIDDAY INTO AFTN IN PRECONVECTIVE AIR MASS. TSTM COVERAGE SHOULD EXTEND AND SHIFT EWD ACROSS NRN/CENTRAL TX THROUGH AFTN AND INTO EVE…AS INFLOW-LAYER AIR MASS MOISTENS.

BUOYANCY WILL DEPEND STRONGLY ON AVAILABILITY OF LOCALIZED POCKETS OF ENHANCED/SUSTAINED INSOLATION OVER CENTRAL TX…AND ABSENCE OF PRECIP/OUTFLOW FARTHER N…NEAR AND N OF I-20. ALTHOUGH LOW-LEVEL WINDS WILL REMAIN WEAK THROUGH MUCH OF AFTN…LIMITING HODOGRAPH SIZE…WRN RIM OF LLJ WILL ENLARGE HODOGRAPHS AROUND 00Z AND THEREAFTER FOR ANY SFC-BASED TSTMS DEVELOPING AND MOVING EWD/ENEWD FROM CENTRAL TO E-CENTRAL/NE TX. THIS CORRIDOR REPRESENTS MOST PROBABLE JUXTAPOSITION OF FAVORABLE BUOYANCY/SHEAR FROM LATE AFTN INTO EVENING. FARTHER S INTO S TX…THOUGH CAPE WILL BE GREATER…SO WILL CINH…AND FOCI FOR CONVECTIVE-SCALE LIFT BECOME MORE UNCLEAR.

…SE TX TO MS DELTA/COAST REGIONS…TONIGHT… ATTM IT STILL IS UNCERTAIN WHETHER TX CONVECTIVE REGIME WILL

1. RUN CONTINUOUSLY INTO LA/MS. SOME SWD BACKBUILDING IS PSBL INTO SE TX AND SWRN LA…THOUGH DEAMPLIFICATION OF UPPER WAVE FARTHER N AND RELATED LACK OF LARGE-SCALE ASCENT EXTENDING SWD ACROSS SABINE RIVER AREA MAY DISFAVOR THAT IDEA.

2. AS MOST CONVECTION-PERMITTING HIGH-RES MODELS SUGGEST…DEVELOP AS SEPARATE AREA OF TSTMS AND BECOME SFC-BASED CLOSER TO GULF COAST OVER LA/MS. FCST SOUNDINGS SUGGEST ACCOMPANYING/WEAKLY CAPPED LOW-LEVEL WAA ZONE THAT WILL BE ACCOMPANIED BY LARGE…SUPERCELL-FAVORING LOW-LEVEL HODOGRAPHS AND STRENGTHENING DEEP SHEAR–E.G. EFFECTIVE SRH EXCEEDING 400 J/KG AND EFFECTIVE SHEAR MAGNITUDES 45-60 KT. THOUGH MID-60S DEW POINTS ARE FCST…LAPSE RATES WILL BE WEAKER THAN FARTHER W…KEEPING MLCAPE/MUCAPE AROUND 1000 J/KG OR LESS. WEAK LOW-LEVEL LAPSE RATES DURING OVERNIGHT HOURS MAY LIMIT VIGOR OF MANY UPDRAFTS…DESPITE TECHNICALLY SFC-BASED CHARACTER OF EFFECTIVE-INFLOW PARCELS IN FCST SOUNDINGS.

 …NRN OK/EXTREME SRN KS… SOME MOIST ADVECTION ALSO MAY EXTEND OUT FROM BENEATH CLOUD SHIELD AND INTO BETTER-HEATED AREAS ACROSS PORTIONS NRN OK/SRN KS…AHEAD OF HIGH-PLAINS COLD FRONT. THIS COULD FOSTER CONDITIONAL/SHORT-LIVED POTENTIAL FOR A FEW STG-MRGL SVR TSTMS IN THAT AREA. MID-UPPER SUPPORT WILL DIMINISH WITH NWD EXTENT…LOW-LEVEL FLOW/SHEAR WILL BE WEAK…AND LOW-LEVEL LIFT IS IN QUESTION GIVEN LACK OF BOUNDARIES OTHER THAN DIFFERENTIAL-HEATING ZONES AND DECAYING/DIFFUSE FRONT. STILL…STEEP DEEP-LAYER LAPSE RATES…MLCAPE 1000-1500 J/KG…AND ENOUGH HEATING TO REMOVE CINH ARE ANTICIPATED…SUGGESTING ISOLATED GUSTS/HAIL NEAR SVR LIMITS MAY OCCUR. MRGL SVR PROBABILITIES ACCORDINGLY HAVE BEEN EXTENDED NWD INTO THIS REGION. ISOLATED TSTMS NEAR SVR LEVELS ALSO MAY FORM ALONG COLD FRONT AFTER DARK AS IT ENCOUNTERS RESIDUAL/MRGLLY FAVORABLE LOW-LEVEL MOISTURE/INSTABILITY. ..EDWARDS/MOSIER.. 03/15/2014

Based on my analysis of the 12Z Upper Air Soundings from SPC, and the following Severe Weather Parameter Values from F5 DATA Severe Weather Software (SWEAT INDEX, SB CAPE, MLCAPE, LIFTED INDICES, BRN INDEX, SFC THETA -E, and 1 – 3 km SRH), based on the GFS and NAM – WRF models, the GREATEST probability for severe weather to occur within the risk area, is outlined in the following map.  The RED outline indicates initiation approximately 4:00 p.m. CST, and BLUE indicates the area between 7:00 p.m. – 10:00 p.m. CST
day1otlk_1300

Albeit the SPC has the risk area well into LA., AND, I cannot rule this out, it appears any severe weather for that area may be an overnight event.

Based on certain values analyzed, rotating supercells are very likely, however any isolated tornadic activity appears that it may occur more toward the southern portions of the TX  area, and mid to north portions of the LA. area.  However, given some subtle differences in model agreement, and some uncertainty in the SPC Outlook text, I urge ALL residents within the risk area to monitor NOAA Weather Radio, Local NWS office statements, and your local media outlets for any Severe Weather statements. ALL of the following are linked.  Click on them to keep you up to date  with real time information throughout the day.

SPC CURRENT CONVECTIVE WATCH DISPLAY

SPC CURRENT MESOSCALE DISCUSSIONS DISPLAY

NWS WATCH, WARNING, and HAZARDS DISPLAY (CLICK ON YOUR STATE)

NWS DOPPLER RADAR LOOP

INTELLICAST NWS DOPPLER RADAR LOOP

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
OFFICIAL SKYWARN SPOTTER (ADVANCED)

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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.
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One Response to SEVERE WEATHER…SLIGHT RISK…FORECAST SYNOPSIS…MAR.15, 2014…ISSUED 1:00 P.M. EDT…PHFC

  1. Monty says:

    Thanks Storm…alerted gang in DFW/IAH/SHV. I gave you a few ideas on your last post…not sure if any of them are worth a damn…just some thoughts. It looks like you have a following of fine people…let’s hope this works. All in all…we WILL find a way Senior Chief!!

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