MESOSCALE PRECIPITATION DISCUSSION 0376
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
204 AM EDT WED JUL 22 2015
 
AREAS AFFECTED...CNTRL AND ERN OKLAHOMA TO FAR ERN ARKANSAS 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 220604Z - 221204Z
 
SUMMARY...EFFICIENT RAINFALL WITH RATES UP TO 2-3 IN/HR WILL
LIKELY CONTINUE TO TRANSLATE EAST AHEAD OF A LOW-MID LEVEL
SHORTWAVE INTO ERN OKLAHOMA AND CNTRL-NRN ARKANSAS. SLOW MOVEMENT
AND BRIEF PERIODS OF TRAINING MAY RESULT IN 6 HR RAINFALL OF 3-5
INCHES IN A FEW LOCATIONS.

DISCUSSION...A WIND SHIFT NOTED IN THE 700 MB VAD WIND PROFILE
PLOT CONFIRMED THE 04Z RAP LOCATION OF A CONVECTIVELY ENHANCED
LOW-MID LEVEL TROUGH AXIS EXTENDING FROM SERN KANSAS INTO CNTRL
OKLAHOMA AT 0530Z. PRECIPITABLE WATER IS ESTIMATED TO BE JUST OVER
2 INCHES ACROSS ERN OKLAHOMA INTO ARKANSAS AHEAD OF THIS FEATURE
BASED ON 00Z AREA SOUNDINGS AND THE LATEST BLENDED TPW PRODUCT.
850-700 MB FLOW HAS BEEN SLOWLY INCREASING OVER THE PAST COUPLE
HOURS AS ADVERTISED AHEAD OF THE UPPER TROUGH AXIS WHICH IS
HELPING TO ALLOW REPEATING CELL MOTIONS. 

AT 0530Z...RADAR SHOWED RATHER DISORGANIZED CONVECTIVE ACTIVITY
WITH THE MAIN CLUSTER OF HEAVY RAIN MOVING THROUGH E-CNTRL
OKLAHOMA AT ROUGHLY 15-20 KTS TOWARD THE ENE...WHILE A SECOND
CLUSTER WAS NOTED IN NWRN ARKANSAS MOVING AT ABOUT THE SAME SPEED.
AS LOW LEVEL WINDS CONTINUE TO INCREASE THROUGH 10Z...TO ROUGHLY
30 KTS AS FORECAST BY THE RAP AHEAD OF THE EWD MOVING TROUGH
AXIS...LINGERING INSTABILITY OF 1000 - 2000 J/KG MLCAPE WILL ALLOW
PERIODS OF TRAINING TO AFFECT LOCATIONS FROM E-CNTRL OKLAHOMA INTO
CNTRL TO NRN ARKANSAS THROUGH 12Z WITH LOCALLY VERY HEAVY RAINFALL
RATES. THIS EVOLUTION HAS BEEN WELL FORECAST BY THE LATEST HI-RES
MODELS...MOST NOTABLY WITH RECENT RUNS OF THE HRRR AND ESRL
EXPERIMENTAL HRRR...WHICH SUGGEST TWO OR THREE LOCATIONS WITHIN
THE THREAT AREA TO RECEIVE BETWEEN 4-8 INCHES BY 12Z. THESE
AMOUNTS ARE LIKELY A BIT HIGH...BUT CAN CERTAINLY SEE AN
ADDITIONAL 3-5 INCHES FOR A FEW LOCATIONS BY 12Z.


OTTO

ATTN...WFO...LZK...MEG...OUN...SGF...TSA...

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

LAT...LON   36549396 36519202 36319007 36008969 35578975 
            35219043 34719438 34089669 34099737 34239780 
            34679798 35259794 35869724 36189675 36519561