MESOSCALE PRECIPITATION DISCUSSION 0124
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
631 PM EDT SUN APR 17 2016
 
AREAS AFFECTED...NWRN TEXAS INTO S-CNTRL OKLAHOMA 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 172230Z - 180300Z
 
SUMMARY...AN INCREASING COVERAGE OF THUNDERSTORMS ACROSS NWRN
TEXAS INTO SRN OKLAHOMA MAY POSE A FLASH FLOOD THREAT...FALLING
OVER AN AREA THAT RECEIVED HEAVY RAIN EARLIER THIS MORNING. AN
ADDITIONAL 2-3 INCHES OF RAINFALL WILL BE POSSIBLE ON A LOCALIZED
BASIS.

DISCUSSION...RADAR TRENDS OUR THE PAST HOUR OR TWO HAVE SHOWN
SCATTERED CONVECTION BECOMING A BIT MORE WIDESPREAD ACROSS
PORTIONS OF NWRN TEXAS...PRIMARILY NORTH OF I-20. PORTIONS OF THIS
AREA RECEIVED 4-8 INCHES OF RAIN OVER THE PAST 24
HOURS...SIGNIFICANTLY LOWERING FLASH FOOD GUIDANCE TO 1-2 INCHES
IN 3 HOURS. INSTABILITY HAS BEEN LIMITED THROUGHOUT THE
AFTERNOON...GENERALLY LESS THAN 500 J/KG...BUT SOME BREAKS IN
CLOUD COVER HAVE ALLOWED TEMPERATURES TO RISE ACROSS SWRN
OKLAHOMA. OKLAHOMA MESONET OBSERVATIONS SHOW 22Z TEMPERATURES IN
THE MID TO UPPER 60S WHICH MAY ALLOW FOR FEW POCKETS OF
INSTABILITY TO RISE INTO THE 500-1000 J/KG RANGE...AT LEAST FOR A
BRIEF TIME BEFORE SUNSET. 

GIVEN RADAR TRENDS AND STORM MOTIONS TOWARD THE NNE AT 25-30
KTS...THERE WILL LIKELY BE SOME TRAINING OF CELLS FROM SW TO NE
OVER THE NEXT FEW HOURS. LOW LEVEL MOISTURE TRANSPORT IS HIGHER
TOWARD THE I-35 CORRIDOR AND THE RIGHT ENTRANCE REGION OF AN UPPER
JET CORE CENTERED OVER THE TEXAS AND OKLAHOMA PANHANDLES MAY ALLOW
FOR SOME ADDED UPPER DIVERGENCE OVER THE REGION...COUPLED WITH
ALREADY PRESENT UPPER DIFFLUENCE. GIVEN THE POCKETS OF HIGHER
INSTABILITY INTO THE EARLY EVENING HOURS...RAINFALL RATES EXCEED 1
IN/HR...AND 3 HR FFG VALUES OF 1-2 INCHES IN 3 HOURS. TRENDS WILL
BE MONITORED INTO THE OVERNIGHT AS ADDITIONAL LOW LEVEL MOISTURE
ADVECTS INTO CNTRL OKLAHOMA AS 850 MB WINDS INCREASE TO 40-45 KTS
VIA SHORT TERM RAP FORECASTS.

OTTO

ATTN...WFO...FWD...OUN...SJT...

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

LAT...LON   35519755 34699649 33689692 32459809 31839917 
            32120002 33219947 34489870