Prognostic Meteorological Discussion
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000
FXUS01 KWBC 192002
PMDSPD

SHORT RANGE FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
402 PM EDT SAT AUG 19 2017

VALID 00Z SUN AUG 20 2017 - 00Z TUE AUG 22 2017

...HEAVY RAIN AND FLASH FLOODING POSSIBLE OVER PARTS OF THE
SOUTHWEST AND PARTS OF THE ROCKIES THIS WEEKEND...

...HEAVY RAINFALL POSSIBLE ALONG A FRONTAL BOUNDARY IN THE UPPER
MIDWEST ON SUNDAY AND INTO MONDAY...

...AFTERNOON SHOWERS AND THUNDERSTORMS MAY LINGER INTO MONDAY
ACROSS THE SOUTHEAST AND GULF COAST STATES...


AN UPPER LEVEL LOW ACROSS THE SOUTHWEST U.S. IS EXPECTED TO MOVE
VERY SLOWLY EASTWARD THROUGH THE REST OF THE WEEKEND AND INTO
EARLY NEXT WEEK. THIS WILL CONTINUE TO TRIGGER DIURNALLY DRIVEN
SHOWERS AND THUNDERSTORMS THE NEXT SEVERAL DAYS FROM THE FOUR
CORNERS REGION INTO THE CENTRAL ROCKIES, AS WELL AS BACK INTO THE
HIGHER TERRAIN OF THE CENTRAL INTERMOUNTAIN WEST AND CALIFORNIA.
HEAVY RAINFALL WILL BE POSSIBLE AND WPC HAS HIGHLIGHTED PORTIONS
OF THESE AREAS IN A MARGINAL TO SLIGHT RISK FOR FLASH FLOODING.
PLEASE REFER TO THE EXCESSIVE RAINFALL OUTLOOKS ISSUED BY WPC FOR
ADDITIONAL DETAILS.

A COLD FRONT MOVING ACROSS THE UPPER MISSISSIPPI VALLEY AND
SOUTHWARD THROUGH THE CENTRAL PLAINS TOMORROW WILL ALLOW FOR THE
DEVELOPMENT OF SHOWERS AND THUNDERSTORMS ALONG THE BOUNDARY ON
SUNDAY, MOVING INTO THE UPPER MIDWEST AND GREAT LAKES ON MONDAY.
STRONG TO LOCALLY SEVERE THUNDERSTORMS AND MODERATE TO HEAVY
RAINFALL WILL BE POSSIBLE, PARTICULARLY ACROSS PORTIONS OF THE
UPPER MIDWEST SUNDAY AND INTO MONDAY AS THE SURFACE FRONT SLOWS
AND EVENTUALLY STALLS ACROSS THIS REGION. WPC HAS HIGHLIGHTED AN
AREA ACROSS IOWA AND INTO NORTHERN MISSOURI WITH A SLIGHT RISK FOR
FLASH FLOODING BOTH SUNDAY AND MONDAY. AFTERNOON HIGH TEMPERATURES
BEHIND THE FRONT ACROSS THE NORTHERN PLAINS SHOULD COOL TO NEAR OR
SLIGHTLY BELOW NORMAL FOR THIS TIME OF THE YEAR.

ELSEWHERE, THE TAIL END OF A BOUNDARY EXITING THE NORTHEAST SHOULD
LINGER ACROSS PORTIONS OF THE SOUTHEAST SUNDAY INTO MONDAY KEEPING
SHOWERS AND THUNDERSTORMS IN THE FORECAST FROM THE SOUTHEASTERN
STATES TO THE GULF COAST. ACROSS THE NORTHEAST AND THE
NORTHWESTERN STATES, SURFACE HIGH PRESSURE SHOULD DOMINATE MUCH OF
THE SHORT RANGE PERIOD WHICH WILL ALLOW FOR MOSTLY CLEAR SKIES,
COMFORTABLE TEMPERATURES, AND LITTLE TO NO RAINFALL.


SANTORELLI

GRAPHICS AVAILABLE AT
WWW.WPC.NCEP.NOAA.GOV/BASICWX/BASICWX_NDFD.PHP
$$




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