136
AWUS01 KWNH 011951
FFGMPD
FLZ000-ALZ000-MSZ000-LAZ000-TXZ000-020200-
MESOSCALE PRECIPITATION DISCUSSION 0156
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
350 PM EDT FRI MAY 01 2026
AREAS AFFECTED...SOUTHEAST TX...SOUTHERN LA...COASTAL MS/AL...
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE
VALID 012000Z - 020200Z
SUMMARY...MULTIPLE ROUNDS OF ELEVATED CONVECTION CAPABLE OF
1.5"-1.75"/HR TRACKING THROUGH A FEW I-10 URBAN CENTERS MAY RESULT
IN LOCALIZED SPOTS UP TO 3" THROUGH EARLY OVERNIGHT. FLASH
FLOODING INCIDENTS REMAIN POSSIBLE.
DISCUSSION...GOES-E WV SUITE DEPICTS A POTENT SHORTWAVE EMANATING
FROM NORTHWEST MEXICO AND THE SOUTHWEST IS STARTING TO
SHEAR/ELONGATE INTO A BROADER LONG-WAVE TROF AS IT MOVES INTO
CONFLUENT FLOW DUE TO THE BROADER NORTHERN STREAM DIGGING TROUGH
SEEN IN THE MIDWEST. THIS IS HELPING TO SUPPORT A STRENGTHENING
RIGHT ENTRANCE REGION OF DOWNSTREAM ACROSS THE LOWER MISSISSIPPI
VALLEY INTO THE 130KT JET OVER THE TENNESSEE VALLEY. THE
COMBINATION OF THE BROAD DPVA AND DIVERGENCE ALOFT SUPPORTS A
BROAD SOUTHERLY FLOW OFF THE WESTERN GULF, BUT VEERING QUICKLY
THROUGH THE LOW TO MID-LEVELS FOR WEST TO EAST FAIRLY
UNIDIRECTIONAL TO SUPPORT A REPEATING ENVIRONMENT FOR ACTIVITY.
THE SURFACE FRONT/BOUNDARY HAS SHIFTED OFFSHORE FOR MOST LOCATION
ALONG THE UPPER TEXAS COAST THROUGH THE CENTRAL GULF COAST, WITH
EXCEPTION OF POSSIBLY THE BIRD'S FOOT OF SE MISSISSIPPI. SOLID
NORTHEASTERLY FLOW NORTH OF THE BOUNDARY IS HELPING TO STEEPEN THE
ISENTROPIC SLOPE AND FURTHER ENHANCED MOISTURE FLUX CONVERGENCE.
THE HIGHER THETA-E AND MODEST LAPSE RATES ALLOWS FOR 500-1000 J/KG
OF MUCAPE THAT HUGS THE COAST, SO SCATTERED ELEVATED CELLS WILL
CONTINUE TO EXIST. OVERALL MOISTURE AVAILABILITY OF .75-.9" OF
SFC TO 850MB PW IS NOTED IN CIRA LPW SUITE BUT MID-LEVEL MOISTURE
REMAINS ELEVATED AS WELL TO KEEP TPW BETWEEN 1.75-2" THROUGHOUT
THE NEXT FEW HOURS TO AID RAINFALL PRODUCTION/EFFICIENCY FOR THESE
ELEVATED CELLS. AS SUCH, INTENSE CORES FOLLOWED BY LIGHT TO
MODERATE RAIN, WITH ADDITIONAL ROUNDS ALLOW FOR SPOTTY 1-3" TOTALS
MAINLY COMING IN THOSE BURSTS. GIVEN THE NUMBER OF LARGER URBAN
CENTERS ALONG I-10, INCREASES INTERSECTION WITH IMPERMEABLE
SURFACES INCREASING RUN-OFF POTENTIAL. SO WHILE MOST OF THE
BROADER SWAMPS AND LOWER WETLANDS ARE NOT LIKELY TO BE AT RISK OF
FFG EXCEEDANCE RESULTING IN FLASH FLOODING; RAPID INUNDATION IN
URBAN CENTERS MAY RESULT IN LOCALIZED FLASH FLOODING.
IT SHOULD BE NOTED, AS THE CORE OF THE SHORTWAVE AND DIVERGENCE
ALOFT SHIFTS EASTWARD TOWARD SUNSET, THE HEIGHT-FALLS SUPPORTS A
WEAK SURFACE WAVE AND NORTHWARD ADVECTION OF THE FRONT PERHAPS
BACK INTO FAR SE LA. THIS SUGGESTS SOME SURFACE BASED CONVECTION
POTENTIAL WILL EXIST TOWARD 00-02Z, WHICH WOULD HAVE HIGHER
RAINFALL RATE POTENTIAL UP TO 2"/HR. CONFIDENCE IS NOT EXTREMELY
HIGH IN THIS EVOLUTION, BUT THERE IS AMPLE LOOSE AGREEMENT IN CAM
SOLUTION FOR SOME SLIGHTLY HIGHER CONCERN IN SE LA LATER THIS
EVENING.
GALLINA
..PLEASE SEE WWW.WPC.NCEP.NOAA.GOV FOR GRAPHIC PRODUCT
ATTN...WFO...HGX...LCH...LIX...MOB...
ATTN...RFC...ALR...FWR...ORN...NWC...
LAT...LON 31108803 30898752 30298754 30128858 29708878
29008895 28868973 28979092 29439247 29539380
29359435 29079493 28489601 28899641 29539630
30289651 30459554 30599338 30749165 30759049
30858950 30918892
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