MESOSCALE PRECIPITATION DISCUSSION 0712
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
950 AM EST SUN DEC 27 2015
 
AREAS AFFECTED...E TEXAS...E OKLAHOMA...ARKANSAS 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY 
 
VALID 271500Z - 272100Z
 
SUMMARY...VERY HEAVY RAINS EXPECTED AS CYCLONE CONTINUES TO MATURE
THIS AFTERNOON WITH AN ELEVATED RISK OF SIGNIFICANT FLASH FLOODING.

DISCUSSION...WV LOOP SHOWS WELL DEVELOPED UPPER LOW ACROSS UPPER
RIO GRANDE WITH STRONG SOUTHERLY DIVERGENT FLOW ACROSS THE
DISCUSSION REGION AS SEEN BY CLASSIC DEEP 'V' CONVECTIVE WEDGE
ACROSS E TX LIFTING INTO E OK/W ARKANSAS.  COLD FRONT IS ANALYZED
FROM A SURFACE LOW EAST OF THE DFW METRO DROPPING DUE SOUTH TO
NEAR LHB BEFORE DEFLECTING BACK WEST TOWARD ANOTHER WEAK
INFLECTION TOWARD SAT/AUS REGION.  THE NORTHERN LOW WILL CONTINUE
TO STRENGTHEN AND LIFT NORTH WITH DEEP 50-60 KT SOUTHERLY FLOW
THROUGH A TREMENDOUS DEPTH FROM BOUNDARY LAYER THROUGH 5H. THIS
WILL CONTINUE TO PUMP HIGHLY ANOMALOUS MOISTURE IN THE RANGE 1.75"
AND GREATER WITH SATURATED PROFILES STILL CAPABLE OF UP TO 1500
J/KG SBCAPES OVER THE DISCUSSION PERIOD...ALLOWING FOR HIGHLY
EFFICIENT RAINFALL PRODUCING CELLS CAPABLE OF 1.75"/HR AND HIGHER
(PARTICUARLY AS SEEN CURRENTLY OVER HENDERSON/VAN ZANDT
COUNTIES...WHERE THE CONVECTION CAN BULGE EASTWARD INTO THE DEEP
SOUTHERLY FLOW).  STRONG UPSTREAM ENERGY TRYING TO ROUND THE BASE
IN DIFFLUENT FLOW SHOULD MAINTAIN UPSTREAM CONVECTIVE DEVELOPMENT
FOR PERSISTENT TRAINING. THIS SHOULD SUPPORT A BROAD AREA OF 6HR
RAINFALL TOTALS TO 3-5" POTENTIALLY LOCALLY HIGHER...CAPABLE OF
FLASH FLOODING CONDITIONS.

FURTHER NORTH AND EAST...
A COLD FRONT TRAILING TOWARD THE SW FROM A SHORTWAVE AND
ASSOCIATED SURFACE LOW EXITING FROM THE OHIO VALLEY WILL CONTINUE
TO SAG SOUTH ACROSS ARKANSAS ALLOWING FOR THE DEEP SOUTHERLY FLOW
TO IMPACT THE ZONE NEARLY PERPENDIULAR TO THE FRONT FOR ENHANCED
MST CONVERGENCE AND CONVECTIVE INITIATION THAT WILL LIFT NORTHWARD
OVER EVENTUALLY SLOPE NORTHWARD PROVIDING MODERATE TO HIGH
RAINFALL TOTALS ACROSS MUCH OF AR/E OK...COMPOUNDING ONGOING
FLOODING CONDITIONS ARCROSS THIS REGION.  ISALLOBARIC INDUCED SSE
AND SE INFLOW FROM LA AND CENTRAL GULF SHOULD ALLOW FOR CLEANER
INFLUX OF MOISTURE NOT TO BE ROBBED BY THE COLD FRONTAL
CONVECTION.  WITH THE DEEPENING LOW...A PIVOT POINT LIKELY OVER SE
OK WILL ALLOW FOR NEARLY STATIONARY MOVEMENT OF THE WESTERN EXTENT
OF THE FRONTAL ZONE IN AR FOR HIGHEST TOTALS THERE TOWARD THE
PIVOT POINT.  SIGNIFICANT POTENTIALLY LIFE THREATING FLASH
FLOODING IS POSSIBLE ACROSS SE OK/NE TX/W AR.

GALLINA

ATTN...WFO...EWX...FWD...HGX...LCH...LZK...MEG...OUN...SHV...
TSA...

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

LAT...LON   36389435 36329164 36089107 35409085 34569143 
            33999305 33319416 32219423 31099431 30349482 
            29999656 30399698 32349643 33939646 35339678 
            36149623 
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