MESOSCALE PRECIPITATION DISCUSSION 0051
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
329 PM EST WED FEB 28 2018
AREAS AFFECTED...NERN TX...ACROSS THE ARKLATEX TO THE AR/MS BORDER
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE
VALID 282029Z - 010035Z
SUMMARY...PERIODS OF TRAINING CONVECTION ARE EXPECTED OVER THE
NEXT FEW HOURS FROM PORTIONS OF NERN TX INTO AND ACROSS THE
ARKLATEX TO THE AR/MS BORDER. RAINFALL RATES OF 1-2 IN/HR WILL BE
POSSIBLE ALONG WITH FLASH FLOODING GIVEN NEAR SATURATED SOILS.
DISCUSSION...AT 20Z...VISIBLE SATELLITE IMAGERY SHOWED AN AREA OF
SOLID CLOUD COVER EXTENDING FROM THE ERN TX/OK BORDER INTO MUCH OF
AR AND TN WITH PARTLY CLOUDY TO MOSTLY CLEAR SKIES TO THE SOUTH.
TEMPERATURES HAVE RESPONDED AND SHOW A BOUNDARY ENHANCED BY
DIFFERENTIAL HEATING WITH TEMPERATURES IN THE 70S TO LOW 80S SOUTH
OF THE BOUNDARY AND 50S TO LOWER 60S TO THE NORTH OF THE BOUNDARY
ALONG WITH STRATIFORM RAIN AND EMBEDDED THUNDERSTORMS. THE LATEST
SPC MESOANALYSIS DEPICTS 500-1000 J/KG MLCAPE SOUTH OF THE
BOUNDARY FROM TEXAS INTO NRN AR.
RECENT RUNS OF THE RAP/HRRR HAVE SHOWN 850-700 MB FLOW BECOMING
BETTER FOCUSED ACROSS ERN TX/NRN LA/SRN AR/CNTRL MS FROM THE
SOUTHWEST...INCREASING INTO THE 40-45 KT RANGE THROUGH 00Z ALONG
AND SOUTH OF THE SURFACE BOUNDARY. GIVEN LARGELY UNIDIRECTIONAL
FLOW ABOVE 850 MB AND THE ELEVATED NATURE OF THE CONVECTION NORTH
OF THE BOUNDARY...TRAINING WILL BE A CONCERN. WHILE INSTABILITY IS
RATHER WEAK...PRECIPITABLE WATER VALUES ARE CURRENTLY 1.6 TO 1.7
INCHES PER RECENT GPS DATA WHICH COULD SUPPORT RAINFALL RATES OF
1-2 IN/HR.
GIVEN RAINFALL OF 1-3 INCHES ACROSS THE MPD THREAT AREA SINCE
YESTERDAY...AND AN EXTREMELY WET ONE TO TWO WEEKS...SOILS ARE
SATURATED IN MANY LOCATIONS ACROSS THE REGION WITH TRAINING OF 1-2
IN/HR RAIN RATES A CONCERN FOR FLASH FLOODING.
OTTO
ATTN...WFO...FWD...HUN...JAN...LZK...MEG...OUN...SHV...TSA...
ATTN...RFC...ABRFC...LMRFC...SERFC...WGRFC...
LAT...LON 35278865 34748809 34078886 33599090 32629500
32519689 33759701 34689442 34709226 35228993
Last Updated: 329 PM EST WED FEB 28 2018