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 291831
QPFERD

EXCESSIVE RAINFALL DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
230 PM EDT SUN MAY 29 2016

...VALID 21Z SUN MAY 29 2016 - 12Z MON MAY 30 2016...
...REFERENCE AWIPS GRAPHIC UNDER...DAY 1 EXCESSIVE RAINFALL...


SLIGHT RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
45 WNW SNK 20 WNW PVW 20 NNW AMA 20 S GUY 15 S LBL 45 E LBL
25 NE WWR 20 WNW END 10 SSW OUN 15 W PVJ 10 NNW GLE NFW
20 SSE SEP 25 SSE SEP 20 W GRK 15 ESE BMQ 10 SW AUS HYI
20 SE BAZ 35 SE SSF 40 E COT 20 ESE COT 15 SSE MMPG 25 SSW DRT
30 NW DRT 40 WSW E29 55 NW E29 55 S BPG 40 NNW BPG 45 WNW SNK.

SLIGHT RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
25 ESE GRD 15 ENE JQF 10 WNW INT 15 ENE MWK MWK 15 NW MWK
15 SSE MKJ 15 SSW MKJ 10 E VJI VJI 15 S LNP 15 W LNP 20 NW LNP
30 NNW LNP 40 S HTS 20 SSE 3I2 20 S PKB 15 ESE PKB 35 S HLG
10 E HLG BVI 20 NNE BVI 20 SSE FKL 15 NNW DUJ ELZ 30 E ROC
10 SE GTB 25 W SLK 25 N SLK CMCW 10 NW CMSB CMSB 10 ESE CMGB
25 SSE CWQH 10 NE 1V4 15 SSE LEB 15 WNW BAF 10 N HPN 10 SSW EWR
15 NW MIV CGE 15 SSW MFV NTU 10 W MQI 35 WNW HSE 30 NE MRH MRH
20 ESE NCA 15 NE ILM 10 WSW ILM CRE 30 SW MYR 25 SE CHS 15 E HXD
20 E SVN 15 N LHW 20 SW TBR 25 W TBR 35 NW TBR AGS 15 NE DNL
25 ESE GRD.

MODERATE RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
25 WSW CAE 20 W CAE 25 NNW CAE 35 NNW CUB 20 SSE UZA 10 SSW VUJ
10 SE HBI 15 W TTA 10 SSE 45J UDG 20 E SSC 25 SE SSC 40 SE SSC
15 NNE CHS 15 SSW CHS 10 WNW NBC 10 NE JYL 25 WSW CAE.


1900 UTC UPDATE

THE SLIGHT RISK AREA CENTERED ALONG THE EASTERN U.S. FROM THE MID
ATLANTIC INTO EASTERN NY WAS EXPANDED WESTWARD INTO THE CENTRAL
APPALACHIANS AND THE SOUTHERN TIER OF NY.  THE SLIGHT RISK WAS
ALSO EXTENDED NORTHWARD INTO THE ADIRONDACKS OF NORTHERN NY AND
EASTWARD INTO THE WESTERN BERKSHIRES OF MA AND THROUGH THE GREEN
MTS OF VT.  THIS WAS TO COVER THE EXPANDING AREA OF CONVECTION
FORMING THIS AFTERNOON ACROSS THESE AREAS IN THE INCREASINGLY
UNSTABLE AIRMASS AHEAD OF THE COLD FRONT MOVING INTO THE GREAT
LAKES AND THE WARM FRONT RETREATING INTO NEW ENGLAND.  NO CHANGES
MADE TO THE THREAT AREAS AHEAD OF BONNIE.  GREATEST THREAT AT THE
MOMENT WILL BE FOR FLARE UPS NEAR THE SLOW MOVING CENTER OVER
SOUTHEAST SC...SUPPORTING 2"+ PER HOUR AMOUNTS.  PLEASE SEE WPC`S
MESOSCALE PRECIPITATION DISCUSSIONS #0262 AND #0263 VALID UNTIL
APPROX 0000 UTC FOR ADDITIONAL INFORMATION ACROSS NEW YORK STATE
INTO NORTHERN NEW ENGLAND AND IN THE VICINITY OF BONNIE

ACROSS THE MID SECTION OF THE NATION...THE 1200 UTC GUIDANCE
CONTINUE TO SHOW A LOT OF RUN TO RUN AND MODEL TO MODEL
VARIABILITY--LEADING TO LOW CONFIDENCE WHERE ORGANIZED CONVECTION
WILL SET UP.  SUBSEQUENTLY...NO CHANGES MADE TO THE VERY BROAD
SLIGHT AREA---WITH POTENTIAL FOR VERY HEAVY TO EXCESSIVE RAINFALL
AMOUNTS WHERE CONVECTION DOES ENHANCE.


1500 UTC UPDATE

CHANGES TO THE PREVIOUS RISK AREAS IN THE VICINITY OF BONNIE WERE
TO EXTEND THE SLIGHT RISK AREA SLIGHTLY SOUTHWARD INTO EAST
CENTRAL PORTIONS OF GEORGIA AS PER LATEST RADAR TRENDS.  THE
MODERATE RISK AREA WAS ALSO EXPANDED SLIGHTLY OVER SOUTHEAST SC TO
ACCOUNT FOR CONVECTION THAT IS FLARING NEAR THE CENTER OF BONNIE.
PLEASE SEE WPC`S MESOSCALE PRECIPITATION DISCUSSIONS #0260 AND
#0261 VALID UNTIL 1843 UTC AND 2030 UTC FOR ADDITIONAL INFORMATION
ACROSS THESE AREAS.

OVER THE SOUTHERN PLAINS...A BROAD SLIGHT RISK AREA WAS MAINTAINED
FROM CENTRAL TX INTO WESTERN OK.  STILL A LOT OF UNCERTAINTIES
WITH DETAILS OF ADDITIONAL CONVECTIVE DEVELOPMENT IN THE VICINITY
OF THE MORE WELL DEFINED OUTFLOW BOUNDARY OVER SOUTH CENTRAL TX TO
THE STATIONARY FRONTAL BOUNDARY IN THE VICINITY OF THE TX
PANHANDLE AND NORTHERN OK.  THERE IS AN OVERALL FAVORABLE PATTERN
FOR ADDITIONAL ACTIVITY TO FIRE IN THE DIFFLUENT FLOW DOWNSTREAM
OF THE SOUTHERN CALIFORNIA CLOSED LOW---BUT THE DETAILS OF HOW
CONVECTION WILL ORGANIZE WARRANTS KEEPING A BROAD SLIGHT RISK AREA.

ORAVEC

PREVIOUS DISCUSSION

...COASTAL SC/EXTREME SRN NC COAST...


HEAVY TO EXCESSIVE RAIN THREAT WILL CONTINUE TO SPREAD NWD WITH
THE SLOW NWWD PROGRESSION OF TS BONNIE INTO SC.  BONNIE REMAINS
EMBDD WITHIN A LARGE NW-SE ORIENTED UPR SHEAR AXIS/TROF TO THE
SOUTH OF AN UPPER RIDGE OFF THE MID ATLC COAST AND WHILE THE
SYSTEM ITSELF WILL WEAKEN THIS PD..DEEP TROPICAL MSTR WITHIN THE
TROF AXIS WILL CONTINUE TO STREAM RAPIDLY NNWWD THRU THE MID ATLC
TOWARD THE NE.  THE APPROACH OF AN UPR TROF OVER THE GT
LAKES/MIDWEST WILL PROVIDE INCREASINGLY CONFLUENT 85H FLOW ACRS
THE MID ATLC REGION BY SUN NIGHT WHERE A PERIOD OF HEAVY RAINS
WITH EMBDD CONVECTION WILL BE PSBL WELL TO THE NORTH OF BONNIE.
SEVERAL HI RES MODEL RUNS SUPPORT A NARROW CORRIDOR OF 1 TO 2"+
RAINS FROM CNTL VA NEWD INTO SE PA AND NRN NJ WHICH ALSO HAS THE
SUPPORT OF THE 00Z UKMET AND HWRF.   MEANWHILE...HI RES MODELS
HAVE DONE A DECENT JOB WITH THE MAINTAINING A HEAVY RAIN CORE ON
THE WRN/SWRN SIDE OF BONNIE`S CIRC AND HAVE TENDED TO FAVOR THE
DEPICTION OF HEAVY RAIN AXIS ACRS SRN SC INTO CNTL SC WITH MID
LEVEL SHEAR AXIS PROVIDING WRN EXTENT OF THE HEAVIER RAINS.
ADDITIONAL RAINS THERE OF 2 TO 4 INCHES WITH PERHAPS ISOLD AMOUNTS
UP TO 6 INCHES...COULD LEAD TO A HEIGHTENED THREAT OF RUNOFF
PROBLEMS AND HENCE HAVE INDICATED A MDT RISK FOR THAT AREA NWD
INTO SCNTL NC. SEE THE LATEST NHC ADVISORIES FOR ADDITIONAL
INFORMATION ON THIS STORM.


...SRN PLAINS...

ADDITIONAL SHORTWAVE ENERGY/JET STREAK WILL BE EJECTING OUT ACRS
NRN MEX/NEW MEXICO INTO TX ON SUN.  STRENGTHENING SLY 85H FLOW
WILL ALLOW PWS TO INCREASE NWD ACRS NRN TX/OK EARLY SUN MRNG WHERE
LEFT EXIT REGION JET WILL HELP AID CONVECTIVE DEVELOPMENT AT START
OF THE PD ALONG OLD FRONTAL BNDRY THAT WILL CONTINUE TO BECOME
MORE DIFFUSE WITH TIME. ADDITIONAL STORMS ARE LIKELY TO DVLP ALONG
AND EAST OF DRY LINE SWD TOWARD THE BIG BEND AREA AND NRN MEX
DURING AFTN HEATING AND SLOWLY PROPAGATE EWD/SEWD INTO THE DEEPER
DOWNSTREAM MSTR  WHILE MODELS SHOW AN INCREASED HEAVY RAIN THREAT
ACRS PARTS OF THE REGION...THERE CONTINUES TO BE LARGE DIFFERENCES
WITH PLACEMENT ESPECIALLY LATITUDINAL-LY HENCE A RATHER BROAD
SLIGHT RISK OF EXCESSIVE RAINS HAS BEEN DEPICTED FROM THE NW/NRN
TX AND WRN OK SWD TOWARD CNTL TX.

SULLIVAN




$$




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