MESOSCALE PRECIPITATION DISCUSSION 0368
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1154 PM EDT THU SEP 11 2014
 
AREAS AFFECTED...EASTERN NM/WEST TX... 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE 
 
VALID 120353Z - 120753Z
 
SUMMARY...CONVECTION HAS GROWN IN AREAL COVERAGE AS THE LOW-LEVEL
UPSLOPE FLOW HAS INCREASED IN RECENT HOURS. THE POST-FRONTAL AIR
MASS IS STILL QUITE MOIST WITH PWATS EXCEEDING 1.50 INCHES WITH
VALUES BEING MAINTAINED BY THE 850-MB SOUTHEASTERLY FLOW. EXPECT
FLASH FLOODING TO OCCUR IN SOME OF THE MORE INTENSE CELLS THROUGH
~08Z.

DISCUSSION...THE DOPPLER RADAR IMAGERY SHOWED THE LATE EVENING
CONVECTION GRADUALLY BECOMING MORE ORGANIZED ACROSS EASTERN NM/FAR
WEST TX. THIS HAS OCCURRED IN RESPONSE TO THE INCREASING UPSLOPE
FLOW WITH VAD WIND PROFILERS SUGGESTING 20 KNOTS OF 850-MB BEING
ADVECTED TOWARD THE SOUTHERN ROCKIES. THE 03Z RAP SUGGESTS THE
MAGNITUDE OF THIS FLOW SHOULD BE MAINTAINED OVERNIGHT AS PWATS OF
1.50 TO 1.75 INCH ADVANCE TOWARD THE REGION. THE 00Z RAOB FROM MAF
SHOWED A RELATIVELY MOIST SURFACE TO 450-MB PROFILE WITH DRIER AIR
CONFINED ABOVE THAT. THE LOW-LEVEL FLOW HAS DEFINITELY ENHANCED
RELATIVE TO THE 00Z SOUNDING. THE 1325 J/KG OF INSTABILITY HAS
DIMINISHED WITH THE LOSS OF SOLAR INSOLATION. HOWEVER...THE 03Z
RAP INDICATES THERE IS STILL SOME ELEVATED INSTABILITY WHICH
REMAINS WITH VALUES OF 250-750 J/KG BECOMING MORE COMMONPLACE.

THE COMBINATION OF THE MOIST UPSLOPE FLOW ALONG WITH SLOW CELL
MOTIONS SUGGESTS THE RISK FOR FLASH FLOODING DURING THE OVERNIGHT
HOURS. WHILE THE HIGH-RESOLUTION GUIDANCE ARE NOT IN COMPLETE
AGREEMENT...THERE ARE ENOUGH SOLUTIONS WHICH DEPICT A HEAVY
RAINFALL SIGNATURE ALONG THE NM/TX BORDER. IN PARTICULAR...THE 02Z
HRRR SHOWS AREAS OF 2 TO 3 INCHES THROUGH 09Z ACROSS SOUTHEASTERN
NM INTO TX.


RUBIN-OSTER

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

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

LAT...LON   34960264 34470204 33860181 33190189 32510222 
            31830231 30870229 30560292 30840385 31610420 
            32810417 34380406 34950362