Quantitative Precipitation Forecast
Issued by NWS

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QPFERD

EXCESSIVE RAINFALL DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
805 PM EDT WED AUG 24 2016

...VALID 01Z THU AUG 25 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
40G 30 S INW 30 ESE SJN 30 NNE GNT 10 E DRO 15 W MYP 25 NNE 20V
15 WSW FNL 15 SW PUB 35 SSE LHX 45 SSW CAO 30 NE ROW 35 E ALM
40 ENE TCS 25 NNE DMN 40 SW SVC 50 NNE DMA 30 WNW PRC 40G.

MARGINAL RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
75 NNE MMCU 55 NNW MRF 25 SSE CVN 35 SW EHA 55 SSW HSI
20 ENE MIW 20 WNW GRR 10 NNE MTC 15 NNW BKL 15 NW PHD LHQ
35 SSW BAK BLV 25 WNW JLN 20 N CHK 70 SW DRT.

SLIGHT RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
20 E GBD 25 SSE BIE 15 NW CNC MLI 15 ESE C75 10 SW BMI
10 SW SPI 15 N DMO 35 NE WLD 25 ESE P28 20 E GBD.


0100 UTC UPDATE...

ONLY COSMETIC CHANGES MADE TO THE DAY 1 EXCESSIVE RAINFALL OUTLOOK
BASED ON THE LATEST SATELLITE AND COMPOSITE RADAR TRENDS...ALONG
WITH THE MORE RECENT RUNS OF THE HRRR AND EXPERIMENTAL HRRR.

HURLEY


PREVIOUS DISCUSSION BELOW...


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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