Quantitative Precipitation Forecast
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000
FOUS30 KWBC 241336
QPFERD

EXCESSIVE RAINFALL DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
935 AM EDT WED AUG 24 2016

...VALID 15Z WED AUG 24 2016 - 12Z THU AUG 25 2016...
...REFERENCE AWIPS GRAPHIC UNDER...DAY 1 EXCESSIVE RAINFALL...


MARGINAL RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
75 NNE MMCU 40 SE GDP 55 S CVN 20 WNW AMA 35 N BGD LBL
35 WSW GCK 50 NNW GCK 35 W HLC 25 E LNK DSM 20 SSW AMN
25 WNW PHN 15 N BKL 10 N DAY FWC 20 W PPF 20 N FDR 15 ENE BPG
40 SSE MAF 125 S E38.

MARGINAL RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
40 SSE LIC 15 E LHX 15 SSW LAA 15 ENE SPD 40 W SPD 40 NW CAO
30 SW CAO 25 NNW TCC 25 SW TCC 55 ESE CQC 35 E 4CR 20 NNW ROW
30 WNW ATS 20 ENE ALM 20 N ALM 35 NNE TCS 35 E SAD 45 ENE FFZ
20 NW PRC 40G 35 WNW SOW 25 SE SJN 40 WNW 4SL 15 ENE DRO
15 NE GUC 20V 30 SSW PUM APA 40 SSE LIC.

SLIGHT RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
20 ENE AAO 10 NW P28 30 ESE DDC 20 NE DDC 30 SW HYS 15 NNW RSL
20 W CNK 15 SSE SDA 10 ESE FFL 15 E MPZ C75 20 ESE PNT 10 NE DNV
10 NE PRG 10 NE MTO 20 SW TAZ 25 SSW PPQ 25 NNW COU 30 SSE LXT
10 WSW UKL 20 ENE AAO.


15Z UPDATE...

ONLY CHANGE WAS TO ADD MARGINAL RISK AREA ACRS PARTS OF THE THE
SRN ROCKIES INTO AZ.  SEE REASONING BELOW. OTHERWISE NO OTHER
CHANGES WERE MADE TO PREVIOUS EXCESSIVE AREAS OR REASONING.

PORTIONS OF THE CENTRAL PLAINS---LOWER MO VALLEY--MID MS VALLEY
INTO THE MID WEST

A FAIRLY LARGE EXCESSIVE RAINFALL POTENTIAL REGION DEPICTED THIS
PERIOD IN THE VICINITY OF THE NEARLY STATIONARY FRONTAL BOUNDARY
EXPECTED TO LIE FROM THE CENTRAL PLAINS INTO THE LOWER MO VALLEY
AND MID MS VALLEY AREA.  MOIST WEST SOUTHWESTERLY LOW LEVEL FLOW
ALONG THIS BOUNDARY---PW VALUES 1.5 TO 2 STANDARD DEVIATIONS ABOVE
THE MEAN---ALONG WITH ENHANCED UPPER DIFFLUENCE ASSOCIATED WITH
SHORTWAVES MOVING EAST NORTHEASTWARD ACROSS THIS REGION---WILL
SUPPORT WIDESPREAD HEAVY RAINFALL POTENTIAL.  WHILE CONFIDENCE IS
FAIRLY HIGH ON THE POTENTIAL FOR ORGANIZED CONVECTION ALONG THIS
BOUNDARY FROM AROUND 0000 UTC THU TO 1200 UTC THU---THERE IS
ENOUGH UNCERTAINTIES WITH THE EXACT AXIS OF THIS MAX PRECIP TO
LOWER CONFIDENCE WITH RESPECT TO THIS AXIS.  UNFORESEEN MESOSCALE
INTERACTIONS WITH THIS EXPECTED ACTIVE CONVECTION IN THE VICINITY
OF THE FRONT MAY GREATLY AFFECT PRECIP DISTRIBUTION AWAY FROM THE
SOLUTIONS OFFERED IN THE LATEST GUIDANCE.  THE CURRENT EARLY
MORNING CONVECTION OVER PORTIONS OF THE UPPER MS VALLEY AND LOWER
MO VALLEY IS AN EXAMPLE OF THIS---WITH LAST NIGHTS GUIDANCE NOT
SHOWING GREAT SKILL WITH THE DETAILS ALTHOUGH THERE WAS AGREEMENT
ON THE OVERALL HEAVY RAINFALL POTENTIAL.  THE INCREASINGLY WEST
SOUTHWESTERLY LOW LEVEL FLOW PARALLEL TO THE BOUNDARY IN THE 0000
TO 1200 UTC THU TIME PERIOD WILL SUPPORT TRAINING POTENTIAL ALONG
THE FRONT FROM IN THE VICINITY OF CENTRAL TO NORTHEAST KS---FAR
SOUTHEAST NE---FAR SOUTHERN IA---NORTHERN MO---NORTH CENTRAL IL
INTO NORTHERN IN.  IN AREAS OF TRAINING--ISOLATED 3-5"+ AMOUNTS
POSSIBLE

SOUTHERN HIGH PLAINS

THERE IS NOT EXPECTED TO BE SIGNIFICANT CHANGES TO THE RECENT
PATTERN OVER THE SOUTHERN HIGH PLAINS.  MOIST SOUTH SOUTHWESTERLY
LOW LEVEL FLOW---WITH UVV ENHANCEMENTS IN THIS MOISTURE AXIS FROM
SHORTWAVES IN THE MID LEVEL SOUTHWEST FLOW ALOFT---WILL SUPPORT
ADDITIONAL WIDESPREAD SCATTERED CONVECTION.  DETAILS WITH THIS
EXPECTED CONVECTION REMAIN LOW---BUT GREATER FOR LOCALLY HEAVY
RAINS AND ISOLATED RUNOFF ISSUES.

SOUTHERN ROCKIES

SCTD PRIMARILY DIURNAL CONVECTION DRIVEN PRIMARILY BY S/WV TROF
MOVING EWD FROM THE 4 CORNERS REGION COULD TRIGGER SOME ISOLD
HEAVIER RAIN TOTALS OVER PORTIONS OF CO/NM/AZ THIS AFTN INTO THE
EARLY OVERNIGHT HOURS.  SOME SPOTTY SHORT TERM RAINFALL TOTALS IN
EXCESS OF 1.5 INCHES IN AN HOUR OR TWO PER LATEST HI RES GUIDANCE
COULD LEAD TO SOME RUNOFF ISSUES ESPECIALLY NEAR STEEPER TERRAIN
AND WHERE FLASH FLOOD GUIDANCE VALUES ARE RATHER LOW.

ORAVEC/SULLIVAN
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