MESOSCALE PRECIPITATION DISCUSSION 0602
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
959 PM EDT THU OCT 22 2015
 
AREAS AFFECTED...NE/N CENT TEXAS...SE OKLAHOMA 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 230158Z - 230758Z
 
SUMMARY...CONVECTIVE OVERRUNNING TO POTENTIALLY REPEAT ALONG
FRONTAL BOUNDARY...MODERATE SHIELD PRECIPITATION DOWNSTREAM OVER
NE TX/SW OK.

DISCUSSION...ALTHOUGH UPPER LEVEL SHORTWAVE CONTINUES TO LIFT
NORTHEASTWARD ACROSS CENTRAL OK...WEAKER THOUGH STILL IMPORTANT
HEIGHT FALLS ARE MOVING IN FROM THE WEST WITH CONTINUED DIFFLUENT
FLOW OVER THE DISCUSSION AREA SUPPORTING WEAK BROAD SCALE UVVS. 
IN THE LOWER LEVELS INCREASING BROAD 40-45KT 85H JET WILL CONTINUE
WITH STRONG MOISTURE FLUX...OF GREATER CONCERN IS WITH LIFTING
WAVE THE DRAPED FRONTAL ZONE AND WEAK COLD POOL IS LEFT ORIENTED
GENERALLY WEST TO EAST MAXIMIZING PERPENDICULAR FLOW TO SUPPORT
ISENTROPIC ASCENT FOR CONVECTIVE DEVELOPMENT.  RAP ANALYSIS SHOWS
1500 J/KG ALONG AND SOUTH OF THE BOUNDARY ADVECTING NORTH TO
MAINTAIN OR SLIGHTLY INCREASING MUCAPES OVER THE SURFACE COLD
POOL.  RAINFALL EFFICIENCY WILL BE INCREASED FURTHER EAST WHERE
DEEPER MOISTURE AVAILABILITY RESIDES...WITH 1.8-1.9" TPW... WHILE
WESTERN VALUES ARE IN THE 1.5" RANGE GIVEN INCREASED DRYING IN THE
MID-LEVELS.   WITH THIS RATES OF 1.0-1.25" WEST AND 1.25-1.5"/HR
EAST ALONG THE BOUNDARY ARE EXPECTED.  THE SIGNIFICANT CONCERN IS
PROBABILITY FOR REPEAT DEVELOPMENT... POTENTIALLY TO COMPOUND
RAINFALL TOTALS.   MOST 

MANY OF THE 12Z HI-RES CAMS WERE TOO SLOW WITH THE EASTWARD
PROGRESS OF THE SURFACE WAVE...AND GENERALLY TOO FAR NORTH WITH
THE HIGHEST RAINFALL TOTALS...THE 12Z NSSL-WRF HAS BEEN PERFORMING
WELL THOUGH TOO FAR NORTH...WHILE THE NEWER HRRR AND ESRL
EXPERIMENTAL HRRR ARE STARTING TO BECOME BETTER ORIENTED AND
CLOSER IN LOCATION TO THE STATIONARY FRONTAL ZONE WITH BETTER
SUPPORT FOR THE LATTER...WHICH INDICATES A BAND OF 3-4" TOTALS
OVER THE NEXT 6HRS FROM MENARD TO HILL/ELLIS COUNTIES. 

FURTHER NORTH AND EAST...THE SURFACE LOW WILL CONTINUE TO MOVE NE
ALONG THE FRONT WITH THE UPPER LEVEL S/W...A NARROW TONGUE OF
INSTABILITIES AHEAD OF THE NORTH-SOUTH ORIENTED COLD FRONT SHOULD
KEEP RATES HIGH...ONCE TRANSVERSING THE BOUNDARY...CELLS WILL
DEVOLVE INTO MODERATE TO HEAVY SHIELD PRECIPITATION ACROSS NE
TX/SE OK...WHERE FLOODING THREAT (IF ANY) WOULD BE LONGER
DURATION/COMPOUNDED TOTALS. 

HI-RES CAMS WERE TOO SLOW WITH THE EASTWARD PROGRESS OF THE
SURFACE WAVE  

GALLINA

ATTN...WFO...FWD...OUN...SHV...SJT...TSA...

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

LAT...LON   35139506 34579458 33389474 32709486 32039591 
            31669764 31399975 31390104 32669929 33139854 
            34559718