MESOSCALE PRECIPITATION DISCUSSION 0608
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1126 AM EDT SAT OCT 24 2015
 
AREAS AFFECTED...TEXAS 
 
CONCERNING...HEAVY RAINFALL...FLASH FLOODING LIKELY 
 
VALID 241515Z - 242115Z
 
SUMMARY...VERY EFFICIENT WARM RAIN PROCESSES ACROSS THE
HIGHLIGHTED AREA ARE EXPECTED TO EXTEND THE THREAT FOR HEAVY
RAINFALL RATES...LEADING TO ADDTIONAL FLASH FLOODING.

DISCUSSION...20-30 KT SOUTHERLY LOW LEVEL FLOW CONTINUES TO
SUPPORT AN ANOMALOUSLY MOIST AIRMASS ACROSS THE REGION.  LATEST
MESOANALYSIS SHOWS 2-2.5 INCH PWS FROM NORTHEASTERN MEX AND THE
WESTERN GULF OF MEX NORTHWARD TO ALONG A NORTHERN STREAM SURFACE
FRONT DROPPING INTO SOUTH TEXAS.  GUIDANCE SHOWS THE BOUNDARY
SLOWING WITH MOIST LOW LEVEL INFLOW PERSISTING AHEAD OF A WEAK
WAVE MOVING OUT THE RIO GRANDE VALLEY ACROSS SOUTH TX LATE THIS
MORNING INTO THE EARLY AFTERNOON.  UPPER DIVERGENCE AFFORDED BY
THE RIGHT-ENTRANCE REGION OF AN UPPER JET EXTENDING FROM THE
SOUTHERN HIGH PLAINS TO THE UPPER MIDWEST WILL CONTINUE TO PROVIDE
LARGER SCALE LIFT.  WITH THE EXCEPTION OF SOUTH TX AND THE TX
COAST...INSTABILITY IS QUITE LIMITED ACROSS MUCH OF THE
HIGHLIGHTED AREA.  HOWEVER...ANOMALOUSLY MOIST PROFILES AS
INDICATED BY MORNING SOUNDINGS FROM CRP AND BRO...WITH ABOVE
FREEZING LEVELS EXTENDING 4.5-5 KM...SUGGEST VERY EFFICIENT WARM
RAIN PROCESSES...RESULTING IN HEAVY RAINFALL RATES AND A
CONTINUATION OF THE FLASH FLOODING THREAT.

WHILE DIFFERING ON THE DETAILS...HI-RES GUIDANCE FROM
OVERNIGHT...AS WELL AS THE LATEST RUNS OF THE OPERATIONAL AND
EXPERIMENTAL HRRR SHOW WIDESPREAD ADDITIONAL TOTALS OF 2-4 INCHES
ACROSS THE HIGHLIGHTED AREA THROUGH 21Z.

PEREIRA

ATTN...WFO...BRO...CRP...EWX...FWD...HGX...

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

LAT...LON   30759650 29599439 28429590 28139651 27369711 
            25989734 26039839 26579907 27199934 27969997 
            28420044 29260005 29879829