Quantitative Precipitation Forecast
Issued by NWS

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FOUS30 KWBC 181812
QPFERD

EXCESSIVE RAINFALL DISCUSSION...CORRECTED
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
211 PM EDT THU SEP 18 2014

...VALID 18Z THU SEP 18 2014 - 00Z SAT SEP 20 2014...
...REFERENCE AWIPS GRAPHIC UNDER...DAY 1 EXCESSIVE RAINFALL...


SLIGHT RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
10 WSW AEG LVS 35 SW DHT 25 NNW CDS 20 SSW SPS 15 SE TRL
30 NW POE 20 SW P92 10 N KVBS 25 NW KGVX 30 E KRP 10 SE LRD
20 ESE 6R6 45 SSE E38 50 SSW MRF 90 SSE MMCS 35 SW MMCS
90 ESE DUG 50 SE DUG 40 NE DUG 50 NE SAD 65 ESE SJN 10 WSW AEG.

MODERATE RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
20 ESE INK 10 SE INK 10 WSW PEQ 25 N MRF 45 WNW MRF 70 SSW GDP
25 SE MMCS 15 SSW MMCS 40 WSW MMCS 85 ESE DUG 50 ESE DUG
40 E DUG 45 WSW SVC 50 NW SVC 70 NW TCS 50 NNW TCS 35 SSW 4MY
15 ENE CQC 20 S TCC 30 N CVN 15 NNE PVW 55 SW F05 10 W SEP
40 SSW SWW 25 SE MDD 20 ESE INK.

MODERATE RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
30 SE HYI 45 SE RND 30 SSE SSF 20 SW SKF 15 SSW ERV 15 NNE T82
15 WNW AUS 30 SE HYI.

HIGH RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
30 SE CNM 35 SE GDP 45 SW GDP 40 E MMCS ELP 65 S DMN 55 SSW DMN
75 SSW DMN 50 ESE DUG 40 WSW SVC 35 NW SVC 30 N SVC TCS
35 ENE ROW 40 ENE ATS 30 SE CNM.


NM/TX BIG COUNTRY/TX BIG BEND
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
LARGE EXCESSIVE RAINFALL AREAS FOR SLIGHT AND MODERATE RISK REMAIN
FROM SOUTHERN NM INTO WEST-CENTRAL TX IN ASSOCIATION WITH THE
REMAINS OF ODILE WHICH ARE MOVING TOWARDS SOUTHWEST NM, WITH A
HIGH RISK OF EXCESSIVE RAINFALL CONTINUING FOR SOUTHERN NM.  THE
FLASH FLOOD GUIDANCE (FFGS) CONTINUES TO LOWER OVER THIS REGION
DUE TO CONTINUED WIDESPREAD RAINFALL.  THE POTENTIAL FOR AREAS OF
LONG DURATION FLOODING REMAINS A CONCERN.  THE HIGHLY ANOMALOUS PW
AVAILABILITY (3-3.5 STANDARD DEVIATIONS ABOVE NORMAL OR 1.75-2")
AND WIDESPREAD RAINFALL/HIGH AREAL-AVERAGE AMOUNTS (1-2.5") WILL
CONTINUE TO LOWER THE FFGS AND ELEVATE THE FLASH FLOODING RISK.
SINCE INSTABILITY CAUSED BY DAYTIME HEATING HAS BUILT ACROSS
PORTIONS OF CENTRAL AND WESTERN TX ALONG WITH ADJACENT PORTIONS OF
NORTHERN MEXICO -- THE MOST RECENT SPC MESOANALYSIS INDICATE CAPE
VALUES ARE IN THE 1000-2000 J/KG RANGE ACROSS TX AND SOUTHEAST NM
WHICH SHOULD ELEVATE THE FLASH FLOOD RISK THIS AFTERNOON AND
EVENING.  RECENT MESOSCALE QPF GUIDANCE INDICATES THAT LOCAL
AMOUNTS OF 3-5" ARE POSSIBLE IN THIS REGION.  SEE MPD #0389 FOR
MORE ON THE SHORT TERM FLASH FLOOD CONCERNS ACROSS FAR WESTERN TX
AND SOUTHERN NM.


TX HILL COUNTRY, PINEY WOODS, & BIG THICKET
SOUTHWEST LA EASTWARD TO THE ATCHAFALAYA
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
INSTABILITY HAS BUILT ACROSS PORTIONS OF TX, WITH RECENT SPC
MESOANALYSES INDICATING CAPE VALUES IN THE 1000-2000 J/KG RANGE
ACROSS TX.  AN AREA OF >2" PRECIPITABLE WATER VALUES AND
UPPER-LEVEL DIFFLUENCE HAVE ALLOWED A BATCH OF THUNDERSTORMS TO
CONSOLIDATE ACROSS SOUTHEAST TX EARLY THIS AFTERNOON.  TONIGHT,
STRENGTHENING LOW-LEVEL INFLOW UP THE RIO GRANDE -- ON THE ORDER
OF 25-35 KTS -- MAY INTERACT WITH OUTFLOW BOUNDARIES EMANATING
FROM THE CONVECTION IN SOUTHEAST TX AND A NEARLY FRONTAL ZONE TO
CAUSE VERY HEAVY RAINFALL ACROSS SOUTH-CENTRAL TX.  THE 12Z ARW,
NMM, SPCWRF, NAM CONEST, NSSL WRF RUNS ALONG WITH THE 16Z HRRR RUN
SHOW A STRONG SIGNAL FOR EXCESSIVE RAINFALL BETWEEN AUSTIN AND DEL
RIO TX OVERNIGHT, WITH MOST OF THE GUIDANCE INDICATING 9"+ AMOUNTS
IN THIS REGION.  CONSIDERING THE VERY LOW FFGS ACROSS THE AUSTIN
AREA DUE TO HEAVY RAINS OVERNIGHT, FELT COMPELLED TO ISSUE A
MODERATE RISK FOR AREAS NEAR AND WEST OF AUSTIN AND TO EXTEND THE
SLIGHT RISK TO THE MIDDLE RIO GRANDE VALLEY OF TX.   SEE MPD #0387
FOR MORE ON THE SHORT TERM FLASH FLOOD CONCERNS ACROSS SOUTHEAST
TX AND SOUTHWEST LA THROUGH ~20Z.


KS/OK/RED RIVER VALLEY OF THE SOUTH
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
DISORGANIZED YET BACKBUILDING THUNDERSTORM ACTIVITY REFUSES TO DIE
ACROSS EASTERN KS, WITH STORMS STREAMING SOUTHWARD TOWARDS THE OK
BORDER.  CANNOT RULE OUT LOCALIZED FLASH FLOODING HERE OVER THE
NEXT SEVERAL HOURS SINCE IT HAS BEEN TENACIOUS SO FAR.  ADDITIONAL
LOCAL AMOUNTS OF 2-4" ARE POSSIBLE WHERE CELLS CONTINUE TO MERGE
AND/OR TRAIN.

ROTH
$$




USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.