Flash Flood Guidance
Issued by NWS

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000
AWUS01 KWNH 290130
FFGMPD
TXZ000-OKZ000-290559-

MESOSCALE PRECIPITATION DISCUSSION 0084
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
930 PM EDT TUE MAR 28 2017

AREAS AFFECTED...CENTRAL TO NORTH-CENTRAL TX/SOUTHWESTERN OK...

CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE

VALID 290129Z - 290559Z

SUMMARY...CONVECTION CONTINUES TO EXPAND IN SPATIAL COVERAGE
MOVING INTO THE EVENING HOURS. MULTIPLE ROUNDS OF HEAVY RAINFALL
WILL LEAD TO AN UPTICK IN THE FLASH FLOOD THREAT AS SOILS BEGIN TO
FURTHER SATURATE. HOURLY RATES MAY APPROACH 1.50 INCHES IN SOME OF
THE MORE ROBUST CONVECTION.

DISCUSSION...THE 01Z SURFACE ANALYSIS INDICATED A FRONTAL SYSTEM
WAS MOVING TOWARD THE RED RIVER WITH A WELL-DEFINED DRY LINE
EXTENDING DOWN THROUGH MIDLAND/ODESSA TX AND JUST EAST OF FORT
STOCKTON TX. STRONG MID/UPPER LEVEL FORCING AHEAD OF A CLOSED LOW
OVER CENTRAL NM WILL CONTINUE TO MOVE INTO AN ENVIRONMENT
CHARACTERIZED BY ABUNDANT MOISTURE AND AMPLE INSTABILITY. A
REPRESENTATIVE 00Z SOUNDING IN THE DOWNSTREAM THERMODYNAMIC
ENVIRONMENT...DALLAS/FT. WORTH...SHOWED MUCAPE VALUES APPROACHING
3000 J/KG AND PRECIPITABLE WATER VALUES AROUND 1.20 INCHES. A
MODEST TEMPERATURE INVERSION WAS NOTED AROUND 700-MB BUT THIS DOES
NOT APPEAR TO BE MUCH OF A HINDERANCE TO VERTICAL MOTIONS GIVEN
THE APPROACHING HEIGHT FALLS. ONE NOTE ABOUT THE TROPOSPHERIC WIND
PROFILE IS THE LOW-LEVEL INFLOW IS NEARLY EQUAL IN DIRECTION/SPEED
TO THAT OF THE MEAN CLOUD-BEARING FLOW SUGGESTING CORFIDI VECTORS
WILL BE NEAR ZERO. RECENT RUNS OF THE RAP DO NOT SHOW THE 850-700
MB WINDS TURNING MORE WESTERLY UNTIL AFTER 05-06Z WHICH SUGGESTS A
TRAINING THREAT WILL EXIST DURING THE NEXT 3 TO 4 HOURS.

THE CURRENT RADAR IMAGERY SHOWED THE LEAD BAND OF
CONVECTION...SOME OF IT ELEVATED IN NATURE...MOVING INTO
SOUTHWESTERN TO CENTRAL OK. RECENT MESONET DATA INDICATED SOME
1-HOUR RAINFALL AMOUNTS HAVE REACHED 1.60 INCHES ACROSS
SOUTHWESTERN OK. BACK TOWARD THE DRY LINE...STRONG CONVECTION HAS
ERUPTED WITH SOME OF THIS ACTIVITY PRIMED TO RETURN TO AREAS WHICH
JUST SAW HEAVY RAINS DURING THE PAST FEW HOURS. WHILE FFG VALUES
HAVE BEEN ON THE HIGHER SIDE GIVEN A LACK OF RECENT RAINFALL...A
LOCALIZED FLASH FLOOD THREAT MAY OCCUR WHERE CONVECTION
REPEATS/TRAINS.

CONSIDERING SOME OF THE LATEST CAMS...THE 12Z HRW-ARW/HRW-NMM-B
REMAIN TOO FAR TO THE EAST AS THEY WERE DURING MPD #0083. MAINLY
BASED ON THE FORECAST ON RECENT RUNS OF THE HRRR INCLUDED THE
HRRR-TLE WHICH INDICATED THE THREAT FOR THE HEAVIEST PRECIPITATION
WILL BE ACROSS SOUTHWESTERN TO CENTRAL OK DURING THE 01Z-05Z
TIMEFRAME.

RUBIN-OSTER

...PLEASE SEE WWW.WPC.NCEP.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...AMA...FWD...LUB...MAF...OUN...SJT...

ATTN...RFC...ABRFC...WGRFC...

LAT...LON   36389835 36179777 35779751 35049750 34219774
            33399812 32529862 31509947 30640089 30760171
            31430193 32230188 33280122 34520010 35709961
            36269917



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