MESOSCALE PRECIPITATION DISCUSSION 0613...CORRECTED
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
856 AM EDT SUN OCT 25 2015
CORRECTED FOR TYPO IN GRAPHIC
AREAS AFFECTED...SOUTHEAST TX...SOUTHERN LA...SOUTHWESTERN MS
CONCERNING...HEAVY RAINFALL...FLASH FLOODING POSSIBLE
VALID 251233Z - 251533Z
SUMMARY...VERY EFFICIENT WARM RAIN PROCESSES WILL CONTINUE TO POSE
THE THREAT FOR HEAVY RAIN ALONG THE UPPER TX COAST AND SOUTHERN LA
THROUGH THE LATE MORNING HOURS.
DISCUSSION...SURFACE LOW THAT DEVELOPED LATE YESTERDAY INTO THE
OVERNIGHT HOURS OVER THE NORTHWESTERN GULF IN RESPONSE TO ENERGY
FROM PATRICIA LIFTING OUT OF NORTHERN MEXICO IS EXPECTED TO
CONTINUE TO TRACK TO THE EAST AHEAD OF A SOUTHERN STREAM TROUGH
DURING THE MORNING HOURS. 40-50 KT SOUTHEASTERLY 850 MB FLOW
AHEAD OF THE CENTER WILL CONTINUE TO SUPPORT THE ANOMALOUSLY DEEP
MOISTURE ALREADY IN PLACE. LATEST MESOANALYSIS SHOWS PWS OF
2-2.25 INCHES ACROSS THE OUTLOOK AREA. LIMITING FACTOR FOR HEAVY
RAINFALL RATES WILL CONTINUE TO BE MARGINAL TO NEGLIGIBLE
INSTABILITY...WITH THE LATEST MESOANALYSIS SHOWING MUCAPE VALUES
OF 100-500 J/KG ACROSS THE AREA. HOWEVER...THE STRENGTH OF THE LOW
LEVEL INFLOW AND ANOMALOUSLY MOIST PROFILES...WITH ABOVE FREEZING
TEMPERATURES EXTENDING UP TO 4.5-5 KM AGL...AS SHOWN BY THE 12Z
LIX SOUNDING...SUGGEST VERY EFFICIENT WARM RAIN PROCESSES...WHICH
MAY RESULT IN LOCALLY HEAVY AMOUNTS.
THE LATEST HI-RES GUIDANCE CONSENSUS CONFINES THE HEAVIEST AMOUNTS
MAINLY TO THE COASTAL AREAS...WHERE WIDESPREAD ADDITIONAL AMOUNTS
OF 1-2 INCHES AND LOCAL AMOUNTS OF 2-4 INCHES THROUGH 18Z ARE
INDICATED. ONE EXCEPTION MAY BE ACROSS SOUTHEASTERN LA...WHERE A
BAND OF TRAINING CELLS THAT ARE CURRENTLY PRODUCING RAINFALL RATES
OF 1-2 IN/HR MAY EXTEND THE HEAVY RAINFALL FURTHER INLAND INTO
SOUTHWESTERN MS. THE LATEST 3-HR FLASH FLOOD GUIDANCE SUGGESTS
THAT OUTSIDE OF THE HOUSTON-GALVESTON AREA THESE AMOUNTS ARE NOT
LIKELY TO CAUSE WIDESPREAD FLASH FLOODING CONCERNS.
PEREIRA
ATTN...WFO...HGX...JAN...LCH...LIX...
ATTN...RFC...LMRFC...WGRFC...
LAT...LON 31389117 30478975 29088935 28909046 29549284
29029493 29979439 30699279
Last Updated: 856 AM EDT SUN OCT 25 2015