Quantitative Precipitation Forecast
Issued by NWS

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000
FOUS30 KWBC 191807
QPFERD

EXCESSIVE RAINFALL DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
206 PM EDT FRI SEP 19 2014

...VALID 18Z FRI SEP 19 2014 - 00Z SUN SEP 21 2014...
...REFERENCE AWIPS GRAPHIC UNDER...DAY 1 EXCESSIVE RAINFALL...


SLIGHT RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
25 NW TCC 15 S BGD 35 NNE CDS 25 SSW RPH 15 ESE ACT 35 NW BPT
15 ENE BPT 10 SE 7R5 25 W KVBS 20 SW GLS 30 S PSX 15 E 2R8
30 WNW ALI 45 SSE MMPG 15 W DRT 35 SSW 6R6 65 SSW 6R6 105 SW 6R6
60 SSW MRF 65 SSW GDP 40 NE ELP 30 WNW 4CR 20 NE CQC 25 NW TCC.

MODERATE RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
15 NW CVS 25 NNE PVW 45 NE SNK 10 NNE SJT 35 WNW E29 50 S E38
30 WSW MRF 40 SW ATS 30 NW ROW 35 E 4CR 15 NW CVS.

MODERATE RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
10 WNW GLS 15 SE LBX 15 SE PSX 10 E PKV 5R5 10 W HOU 10 WNW GLS.


SOUTHEAST NM/WESTERN TEXAS
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
A DEEP MOISTURE PLUME ASSOCIATED WITH ODILE -- WITH PWS OF
1.50-1.75" -- ALONG WITH ANOTHER ANOMALOUS PW AXIS SETTING SAIL
WELL TO THE NORTH AND NORTHEAST OF T.S. POLO INTO WESTERN TX, WILL
CONTINUE TO OVERWASH A STALLED W-E STATIONARY FRONT ACROSS
SOUTH-CENTRAL AND SOUTHEAST TX THROUGH THE PERIOD. SOUTH TO
SOUTHEAST LOW-LEVEL FLOW WILL CONTINUE AHEAD OF ODILE`S
SLOW-MOVING CENTER OF CIRCULATION -- CURRENTLY VOYAGING THROUGH
SOUTH-CENTRAL NM -- WITH THE INFLOW WEAKENING DURING THE DAY TODAY
AND SATURDAY AND RESTRENGTHENING SOMEWHAT OVERNIGHT DUE TO THE
NOCTURNAL LOW-LEVEL JET.  WEAK ANTECEDENT UPPER-LEVEL FORCING
WITHIN THE BROAD UPPER RIDGE WILL GET A BOOST AHEAD OF THE
ODILE-RELATED CIRCULATION AND WITH INCREASED UPPER LEVEL
DIFFLUENCE.  SATURATED SOILS BEDEVIL THE REGION -- THEY CANNOT
STAND ANY ADDITIONAL RAINFALL FROM ANY SORT OF THUNDERSTORM,
REGARDLESS OF ITS CONVECTIVE MODE.  THUNDERSTORMS WHICH FORM
WITHIN THE REGION COULD ORGANIZE AS 0-6 KM BULK SHEAR IS NEAR 25
KTS.  CONVECTION SHOULD BECOME MORE PERIPHERAL TO THE CIRCULATION
DURING THE DAY AND CLOSER TO ITS CIRCULATION CENTER OVERNIGHT.
PER THE MOST RECENT MESOSCALE QPF GUIDANCE... LOCALIZED AMOUNTS OF
4-8 INCHES ARE POSSIBLE -- MOST LIKELY OVER THE TRANS-PECOS AND
BIG COUNTRY PORTIONS OF TX AND SOUTHEAST NM WHERE THE MODERATE
RISK FOR EXCESSIVE RAINFALL WAS PLACED -- AS THE OVERALL
MOISTURE-RICH ENVIRONMENT (WARM RAIN PROCESSES) WILL CONTINUE TO
SUPPORT RAINFALL RATES UP TO 2.5" PER HOUR.


SOUTH-CENTRAL/SOUTHEAST TX
~~~~~~~~~~~~~~~~~~~~~~~~~~
A SEA OF ANOMALOUSLY HIGH MOISTURE, IN THE 2-2.5" PW RANGE, NEAR
TO ABOVE THE 90TH PERCENTILE FOR MID-SEPTEMBER, LIES CLOSER TO THE
SURFACE BOUNDARY OVER AN INCREASINGLY SATURATED AREA.  ACROSS
SOUTH-CENTRAL TX, CONVECTIVE ORGANIZATION IS POSSIBLE CONSIDERING
25 KTS OF 0-6 KM BULK SHEAR ADVERTISED BY RECENT RAP GUIDANCE.
INSTABILITY CAUSED BY DAYTIME HEATING IN LEAGUE WITH THE AVAILABLE
MOISTURE SUPPLY SHOULD GUARANTEE THUNDERSTORM ACTIVITY WITH HEAVY
RAINFALL THIS AFTERNOON AND EVENING.  OTHER THUNDERSTORMS ARE
POSSIBLE ACROSS SOUTHEAST TX THIS AFTERNOON IF SUNNY SKIES BREAK
OUT LATER TODAY.  OVERNIGHT, ANOTHER BATCH OF THUNDERSTORMS IS
EXPECTED ACROSS THE MIDDLE AND UPPER TX COASTLINES NORTH OF THE
FRONTAL ZONE, WHICH SHOULD HAVE SOME ASSOCIATED CIN BY THAT TIME.
HOURLY RAIN RATES IN THIS MOIST ENVIRONMENT COULD REACH 3" AN
HOUR.  SOME OF THE MESOSCALE GUIDANCE INDICATED THAT LOCAL AMOUNTS
OF 3-6" ARE POSSIBLE IN THIS REGION, SO MAINTAINED A MODERATE RISK
OF EXCESSIVE RAINFALL IN THIS REGION.


ARIZONA
~~~~~~~
PRECIPITABLE WATER VALUES (PWS) OF 1.75" COMBINED WITH DAYTIME
HEATING TODAY SHOULD LEAD TO TYPICAL MONSOON-LIKE THUNDERSTORM
DEVELOPMENT THIS AFTERNOON AND TONIGHT ACROSS SOUTHEAST AZ.  THE
0-6 KM BULK SHEAR (20 KTS OR LESS) AND MAGNITUDE OF THE 700 HPA
INFLOW (10 KTS) IMPLY SINGLE CELL/PULSE CONVECTION TODAY OVER
ANYTHING ORGANIZED.  HOURLY RAIN RATES UP TO 2" ARE POSSIBLE WHERE
CELLS MERGE, WHICH COULD LEAD TO A FEW POCKETS OF FLASH FLOODING
THIS AFTERNOON AND EVENING.  LIMITED FLASH FLOODING/DEBRIS FLOWS
COULD OCCUR AGAIN TOMORROW AFTERNOON AND EVENING AS WELL ACROSS
THE MOGOLLON RIM AND SOUTHERN WASATCH AS MOISTURE RETURNS INTO THE
REGION.

ROTH
$$




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