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 180050
QPFERD

EXCESSIVE RAINFALL DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
850 PM EDT SUN SEP 17 2017

...VALID 01Z MON SEP 18 2017 - 12Z MON SEP 18 2017...
...REFERENCE AWIPS GRAPHIC UNDER...DAY 1 EXCESSIVE RAINFALL...


MARGINAL RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
45 SSE CDS 35 SE AMA 10 WNW BGD 45 E LBL 20 SSW HLC 10 E HSI
25 WNW FNB EMP 10 W PNC 15 WSW PWA 20 NNE PVJ 10 E MKO
25 SSW RKR 30 NE RPH 45 SSE CDS.


...SOUTHERN PLAINS...

THIS EVENING THUNDERSTORMS WERE ONGOING ALONG A SURFACE FRONTAL
BOUNDARY FROM EASTERN OKLAHOMA INTO NORTH TEXAS. SLOW CELL MOTIONS
AND SOME SOUTHWEST TO NORTHEAST TRAINING HAD ALREADY LED TO A
COUPLE OF SMALL SCALE BUT INTENSE HEAVY RAIN EVENTS IN EASTERN
OKLAHOMA AND NORTH TEXAS. AT 0030Z THESE EVENTS WERE WANING AS A
LEAD SHORTWAVE EXITED THE AREA PER WATER VAPOR IMAGERY...AND AS
LARGER SCALE HEIGHT FALLS BECAME ORGANIZED BACK TO THE WEST.

CONVECTION ROLLING OUT OF THE SOUTHERN HIGH PLAINS / SOUTHERN TX
PANHANDLE WAS IN A DRIER ENVIRONMENT...PROMOTING OUTFLOW...BUT
THERE WILL BE A BRIEF WINDOW IN WHICH MULTIPLE SWATHS OF MODERATE
RAINFALL COULD MOVE OVER THE SAME AREAS...BOOSTING EVENT TOTAL
RAINFALL TO AROUND 2 INCHES IN ISOLATED SPOTS THROUGH ABOUT 04Z.
WITH TIME...THIS ACTIVITY WILL MOVE INTO A MORE MOISTURE-RICH
ENVIRONMENT FARTHER EAST...BUT THIS WILL BE OFFSET BY A DECREASE
IN INSTABILITY OWING TO THE OVERTURNING THAT ALREADY OCCURRED IN
MUCH OF CENTRAL AND SOUTHERN OKLAHOMA.

THE MORE PRONOUNCED RISK OF NEWLY DEVELOPING HEAVY RAINFALL WILL
LIKELY OCCUR FARTHER NORTH...AS DEEP LAYER FORCING BRINGS CLUSTERS
OF THUNDERSTORMS ROLLING OFF THE COLORADO HIGH PLAINS AND
INCREASING IN COVERAGE THROUGHOUT WESTERN/CENTRAL KANSAS AND FAR
SOUTHERN NEBRASKA OVERNIGHT. WITH LOW LEVEL INFLOW INCREASING
DURING THIS TIME...SOME BETTER ORGANIZATION OF HEAVY RAIN AREAS
MAY OCCUR...WHICH SUPPORTS MAINTAINING THE MARGINAL RISK OF
EXCESSIVE RAINFALL...AND EVEN EXPANDING IT TOWARD OMAHA BASED ON
HRRR AND RAP TRENDS. PRECIPITABLE WATER VALUES...INFLOW...AND
RAINFALL EFFICIENCY...SHOULD INCREASE WITH TIME DURING THE
OVERNIGHT HOURS...AND SEVERAL HI-RES MODELS CLUSTER THEIR MODERATE
TO HEAVY RAIN SIGNAL NEAR AND NORTH OF INTERSTATE 70.

BURKE
$$




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