Quantitative Precipitation Forecast
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FOUS30 KWBC 271421
QPFERD

EXCESSIVE RAINFALL DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1020 AM EDT FRI MAY 27 2016

...VALID 15Z FRI MAY 27 2016 - 12Z SAT MAY 28 2016...
...REFERENCE AWIPS GRAPHIC UNDER...DAY 1 EXCESSIVE RAINFALL...


SLIGHT RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
10 W RDK 25 WNW EOK 10 NW IJX 35 WNW SUS 15 NNW AIZ 55 ENE CNU
20 ESE EWK 20 NE HUT CNK 10 SE HJH 25 NW BIE 10 E LNK 10 W RDK.

SLIGHT RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
15 N JSO 30 NW IER 35 ENE ELD 20 E SRC 30 SE M19 10 ENE UTA
20 SW TVR 25 N LFT 15 ESE BPT 30 NW SGR 15 SE HYI 15 NNW HYI AUS
15 ESE GTU 20 ENE GTU ILE 25 N 6R9 25 SSW BWD 20 WSW BWD
25 NW 7F9 15 ENE INJ 15 N JSO.

MODERATE RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
30 SW FNB 15 S FNB 25 ESE STJ 25 NNE LXT LXT IXD 30 NE UKL
10 E EMP 20 SSW EMP 30 SW EMP 25 NE EWK 10 N EWK 25 NNW EWK
15 SE SLN 15 ENE SLN 30 ESE CNK 35 ENE CNK 40 SSE BIE 30 SW FNB.

MODERATE RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
20 WNW 05F 25 SSE 7F9 10 SSW BWD BWD 10 NNE BWD 15 S SEP
25 SE SEP 25 SW GDJ 20 WSW INJ CNW 20 WNW 05F.

MODERATE RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
20 ENE 3T5 25 W 3T5 15 WNW 62H 15 ENE CLL 20 WNW UTS 20 E UTS
30 ENE CXO 35 ESE CXO 30 ENE IAH 20 ENE 3T5.


1500 UTC UPDATE

CENTRAL TO SOUTHEAST TX INTO THE LOWER MS VALLEY

SOME SIGNIFICANT CHANGES MADE TO THE PREVIOUS EXCESSIVE RAINFALL
POTENTIAL OUTLOOK FOR THE DAY 1 TIME PERIOD.  THE BROAD RISK AREA
WAS SEPARATED INTO TWO AREAS AS PER LATEST RADAR TRENDS AND HI RES
SHORT TERM GUIDANCE.  THE SOUTHERN RISK AREA WAS EXPANDED WESTWARD
INTO CENTRAL TX TO ACCOUNT FOR CONVECTION THAT CONTINUES TO FOCUS
ALONG AND JUST NORTH OF A WELL DEFINED OUTFLOW BOUNDARY OVER
CENTRAL TO SOUTHEAST TX.  MOIST SOUTH SOUTHWESTERLY LOW LEVEL FLOW
INTO THIS BOUNDARY WILL CONTINUE TO SUPPORT POTENTIAL FOR
CONVECTION TO REFORM ON THE WESTERN PORTION OF THE OUTFLOW AND
TRAIN DOWNSTREAM.  THIS MAY LIMIT THE NORTHWARD PUSH OF
PRECIP---WITH THIS THE PRIMARY REASON THE THREAT AREA WAS SPLIT
INTO TWO AREAS.  THE HRR---HRRP AND HRRR EXPERIMENTAL SEEM TO HAVE
THE BEST HANDLE ON THIS CURRENT ACTIVITY---ALL SUGGESTING THE
HEAVY RAIN THREAT WILL CONTINUE INTO THIS AFTERNOON ALONG AND
NORTH OF THIS BOUNDARY---BUT REMAIN CENTERED FARTHER TO THE SOUTH
THAN SOME OF THE OTHER GUIDANCE IS SHOWING.  TOWARD THE END OF
THIS FORECAST PERIOD---EARLY MORNING HOURS OF
SATURDAY---CONVECTION MAY PUSH SOUTHWARD BACK INTO AREAS WHERE THE
FFG VALUES HAVE LOWERED SIGNIFICANTLY OVER SOUTHEAST TX.  FOR THIS
REASON---THE PREVIOUS MODERATE RISK AREA WAS PUSHED SOUTHWARD AND
ANOTHER MODERATE AREA WAS ADDED BETWEEN WACO AND BROWNWOOD FOR
CURRENT ACTIVITY AND LOW FFG VALUES.

OVER EASTERN KS AND NORTHERN MO...

THE MODERATE RISK AREA WAS EXPANDED WESTWARD INTO NORTHEAST KS TO
COVER THE LOWER FFG VALUES.  MODELS CONTINUE TO SUGGEST HEAVY RAIN
POTENTIAL LATER THIS PERIOD...AFTERNOON INTO THE OVERNIGHT HOURS
TO THE NORTHEAST OF THE EJECTING CENTRAL HIGH PLAINS CLOSED LOW.
STILL SOME UNCERTAINTIES HOW ANY ORGANIZED ACTIVITY TO THE SOUTH
WILL DISRUPT THIS POTENTIAL---BUT WITH FFG VALUES SO LOW---BELIEVE
THE RUNOFF THREAT WILL REMAIN OVER EASTERN KS INTO NORTHERN MO.

ORAVEC

PREVIOUS DISCUSSION

...ERN KS/SE NEB/MO/AR/LA/ERN TX...

A RATHER LARGE SLIGHT RISK AREA IS DEPICTED FOR DAY ONE AS ANOTHER
DAY OF ACTIVE WEATHER IS EXPECTED ACRS MUCH OF THE CNTL U.S. IN
ADVANCE OF A SLOW MOVING UPR TROF LIFTING NEWD OUT OF THE CNTL/SRN
ROCKIES.    VERY MOIST UNSTABLE AIRMASS AHEAD OF THIS FEATURE
COMBINED WITH HEIGHT FALLS AND DIFFLUENT FLOW ALOFT WILL ONCE
AHEAD LEAD TO NUMEROUS SHOWERS/TSTMS FROM THE SRN/CNTL PLAINS AND
EXTENDING EAST OF THOSE AREAS.  WHILE THE GLOBAL MODELS SHOW
REASONABLY SIMILAR HANDLING OF THE UPR LOW/TROF...MODELS CONTINUE
TO STRUGGLE SHOWING ANY CONSISTENCY/AGREEMENT WITH CONVECTIVE
DEVELOPMENT AND THIS INCLUDES MOST OF THE HI RES CONVECTIVE
ALLOWING MODELS AS WELL.  THIS LEADS TO RATHER LOW CONFIDENCE IN
TIMING/PLACEMENT OF HEAVIER PCPN...THOUGH THERMAL/MSTR
CONSIDERATIONS WITH PWS WELL IN EXCESS OF 1.75 INCHES ACRS THE SRN
PLAINS INTO THE MID MS VALLEY WOULD GENLY SUPPORT CONTINUED THREAT
OF ORGANIZED HEAVY TO EXCESSIVE RAINS..FROM PARTS OF THE MID MS
VALLEY SWD THRU ARKANSAS/WRN LA AND ERN TX.  HOW REMNANT OUTFLOW
BNDRIES FROM OVERNIGHT MCS ACTIVITY OVER SRN TX AS WELL AS CNTL KS
PLAY OUT THIS MRNG IS QUITE THE CHALLENGE AS AGAIN HI RES GUIDANCE
INCLUDING MULTIPLE HRRR RUNS HAVE NOT DONE PARTICULARLY WELL.
HOWEVER..MOST SUGGEST A SLIGHT EWD FOCUS FROM MOST OF THE GLOBAL
GUIDANCE FOR SUBSEQUENT DEVELOPMENT TODAY/TONIGHT ACRS THE SOUTH
AND THIS IDEA WAS GENLY FOLLOWED.   THE THREAT OF EXCESSIVE RAINS
WILL BE FUELED BY 40 KT SLY 85H FLOW AND GREATER THAN 1.75 INCH
PROVIDING STG MSTR FLUX WELL AHEAD OF THE UPR TROF.  EXPECT SOME
SHORT TERM RAINFALL RATES OF 1 TO 2 INCHES THRU PARTS OF ERN KS/SE
NEB AND MO PRIMARILY FRI AFTN/EVE AS MAIN HEIGHT FALLS WORK EWD
AND HELP DESTABILIZE THE REGION AHEAD OF THE ASSOCD COLD
FRONT...WHILE HEAVIER AMOUNTS ARE PSBL FARTHER SOUTH ACRS THE
ARKLATEX IN PROXIMITY TO HIER MSTR AND DEEPER LAYERED SSWLY FLOW
THAT COULD PROMOTE TRAINING.  EARLIER HEAVY RAINS HAVE LOWERED FFG
VALUES SIGNIFICANTLY ACRS PARTS OF NE KS/MO AND ERN TX SO THAT IT
WON`T TAKE MUCH ADDITIONAL RAINS ACRS THOSE AREAS TO EXACERBATE
RUNOFF PROBLEMS.


SULLIVAN
$$




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