MESOSCALE PRECIPITATION DISCUSSION 0369
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
354 AM EDT FRI SEP 12 2014
 
AREAS AFFECTED...SOUTHEASTERN NM/WEST TX... 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 120753Z - 121153Z
 
SUMMARY...SLOW-MOVING UPSLOPE DRIVEN CONVECTION HAS PERSISTED
OVERNIGHT ACROSS SOUTHEASTERN NM INTO FAR WEST TX. NUMEROUS FLASH
FLOOD WARNINGS HAVE BEEN ISSUED FOR THIS CONVECTION WITH DOPPLER
ESTIMATES OF 3 TO 5 INCHES OF RAINFALL IN THE PAST 6 HOURS. THE
PERSISTENCE OF THE MOIST UPSLOPE FLOW WILL KEEP A THREAT FOR FLASH
FLOODING BEYOND 12Z...ESPECIALLY AS SOILS CONTINUE TO BECOME
FURTHER SATURATED.

DISCUSSION...THE 07Z SURFACE ANALYSIS SHOWED A BAROCLINIC ZONE
STRETCHING FROM SOUTH OF WACO TX SOUTHWESTWARD ALONG THE RIO
GRANDE AND INTO SOUTH-CENTRAL NM. THE POST-FRONTAL AIR MASS ACROSS
THE MPD AREA REMAINS QUITE MOIST AS LOW-LEVEL MOISTURE POOLS NORTH
OF THE FRONTAL ZONE. THE 06Z RAP SHOWED PWATS OF 1.50 TO 1.75
INCHES ENTRENCHED OVER THE REGION WITH PERSISTENT 15 TO 20 KNOT
UPSLOPE FLOW NOTED IN THE VAD WIND PROFILERS. 

THE SYNOPTIC PATTERN IN PLACE WILL REMAIN FAVORABLE FOR CONTINUED
CONVECTIVE DEVELOPMENT.  
A VERY SLOW MOVING MID-LEVEL VORTICITY CENTER WAS SEEN DRIFTING
TOWARD THE NORTHEAST WHILE UNDER THE RIGHT ENTRANCE REGION OF A
MODEST UPPER JET STREAK. THIS SETUP HAS ALLOWED THUNDERSTORM
ACTIVITY TO CONTINUALLY REGENERATE OVER SOUTHEASTERN NM WITH MUCH
OF THE CONVECTION REMAINING NEARLY QUASI-STATIONARY AGAINST THE
TERRAIN.

THERE IS A PRETTY CLEAR SIGNAL IN THE HIGH-RESOLUTION GUIDANCE
THAT HEAVY RAINFALL IS LIKELY THROUGH AT LEAST 12Z. THE 06Z HRRR
AND 00Z HRW-ARW AND GEM REGIONAL ALL DEPICT 2 TO 4 INCHES OF
RAINFALL THROUGH 12Z ACROSS THE AREA HIGHLIGHTED ON THE MPD
GRAPHIC. THIS WILL FALL ON TOP OF ALREADY SATURATED SOILS FROM
HEAVY RAINFALL EARLIER TONIGHT. THUS...FLASH FLOODING WILL BE
POSSIBLE THROUGH AT LEAST 12Z.



RUBIN-OSTER

ATTN...WFO...ABQ...LUB...MAF...SJT...

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

LAT...LON   34670140 34510094 33870037 33130017 32460016 
            31990038 31540106 31470191 31640274 31790356 
            31780436 32410462 33410393 34290275 34600195