Graphic for MPD #0455

MESOSCALE PRECIPITATION DISCUSSION 0455
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1014 AM EDT SAT JUL 08 2017

AREAS AFFECTED...ERN OK INTO WRN AR

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

VALID 081413Z - 081800Z

SUMMARY...LOCALIZED FLASH FLOODING WILL BE POSSIBLE ACROSS
PORTIONS OF ERN OK INTO FAR WRN AR WITH RAINFALL RATES OF 1-2
IN/HR AND BRIEF TRAINING. THE THREAT IS EXPECTED TO END AROUND 17Z.

DISCUSSION...RADAR IMAGERY OVER THE PAST SEVERAL HOURS HAS SHOWN A
SOMEWHAT DISORGANIZED AREA OF ELEVATED SHOWERS AND THUNDERSTORMS
EVOLVING ACROSS NERN OK INTO WRN AND SRN AR. THE ACTIVITY IN SRN
AR HAS BEEN PROGRESSIVE TOWARD THE SOUTH AHEAD OF A LOW-MID LEVEL
SHORTWAVE TROUGH TRANSLATING TO THE SOUTHEAST. FARTHER WEST OVER
NORTHEAST OK AND THE CNTRL OK/AR BORDER...STORMS HAVE BEEN SLOWER
MOVING AND HAVE HAD A HISTORY OF TRAINING IN WEAK NWLY FLOW. A
RESULTANT OUTFLOW BOUNDARY WAS ANALYZED AT 14Z FROM SRN AR...NWWD
INTO E-CNTRL OK AND NOW PARALLELS STORM MOVEMENT. FLOW ALOFT IS
ALSO HIGHLY DIFFLUENT WHICH MAY BE A SIGNIFICANT FACTOR IN THE
PERSISTENCE OF THESE STORMS GIVEN THE UNFAVORABLE TIME OF DAY NEAR
SUNRISE.

GPS SITE PRECIPITABLE WATER VALUES SHOW A BIT HIGHER ACROSS ERN
OK...1.7 TO 2.1 INCHES...COMPARED TO 12Z RAOBS FROM OUN AND LZK
WHICH DISPLAYED PRECIPITABLE WATER VALUES NEAR 1.5 AND 1.6 INCHES.
WHILE MANY FACTORS POINT TO WEAKENING BY 17-18Z...NAMELY
DECREASING UPPER DIFFLUENCE AND A DISRUPTION TO THE LOW LEVEL WIND
FIELD...LOCATIONS ACROSS ERN OK INTO WRN AR HAVE RECORDED 400 TO
OVER 600 PERCENT OF NORMAL RAINFALL OVER THE PAST WEEK. THE RECENT
HEAVY RAINFALL MAY MAKE LOCATIONS ACROSS THE REGION MORE
SUSCEPTIBLE TO FLASH FLOODING AS ACTIVITY LIKELY BUILDS SOUTH OVER
THE NEXT COUPLE OF HOURS. RAINFALL RATES OF 1-2 IN/HR WITH BRIEF
TRAINING MAY CAUSE FLASH FLOODING IN ONE OR TWO LOCATIONS.

OTTO

ATTN...WFO...LZK...OUN...SHV...TSA...

ATTN...RFC...ABRFC...LMRFC...

LAT...LON   36559553 36409502 35769469 35279411 34909396
            34419396 34019458 34089536 34429597 35209627
            36279609


Last Updated: 1014 AM EDT SAT JUL 08 2017