Prognostic Meteorological Discussion
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000
FXUS01 KWBC 212000
PMDSPD

SHORT RANGE FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
400 PM EDT MON AUG 21 2017

VALID 00Z TUE AUG 22 2017 - 00Z THU AUG 24 2017

...FLASH FLOODING AND SEVERE WEATHER POSSIBLE FROM PORTIONS THE
UPPER/MIDDLE MISSISSIPPI VALLEY TO NEW ENGLAND THROUGH TUESDAY
MORNING...

...FLASH FLOODING AND SEVERE WEATHER POSSIBLE FROM PORTIONS OF THE
CENTRAL/SOUTHERN PLAINS TO THE MID-ATLANTIC MORNING...

...HEAVY RAINFALL WILL CONTINUE ACROSS THE SOUTHERN ROCKIES
TODAY...

A SURFACE LOW PRESSURE SYSTEM MOVING THROUGH THE CENTRAL U.S. WILL
BE THE FOCUS FOR SHOWERS AND THUNDERSTORMS OVER THE NEXT FEW DAYS.
THE LEADING AREA OF LOW PRESSURE WILL LIFT THROUGH THE UPPER
MIDWEST/GREAT LAKES INTO EASTERN CANADA BY MIDWEEK WHILE A COLD
FRONT MOVES SOUTH AND EAST THROUGH THE CENTRAL AND EASTERN U.S.
STRONG TO SEVERE THUNDERSTORMS WILL BE CAPABLE OF PRODUCING HEAVY
RAINFALL OVER PORTIONS OF THE SOUTHERN/CENTRAL PLAINS, MISSISSIPPI
VALLEY, MID-ATLANTIC AND NORTHEAST AS THE SYSTEM PASSES THROUGH.
AREAS WITH HEAVY RAINFALL WILL HAVE AN INCREASED RISK FOR FLASH
FLOODING. THE STORM PREDICTION CENTER HAS HIGHLIGHTED PARTS OF THE
NORTHERN PLAINS AND UPPER MISSISSIPPI VALLEY AS HAVING A SLIGHT
RISK FOR SEVERE WEATHER ON TUESDAY... AND FROM THE OHIO VALLEY TO
THE NORTHEAST ON WEDNESDAY. AREAS OF EXCESSIVE RAINFALL HAVE BEEN
HIGHLIGHTED BY WPC FROM NEBRASKA TO WISCONSIN ON TUESDAY... AND
OKLAHOMA AND ARKANSAS ON WEDNESDAY.

PARTS OF THE SOUTHERN ROCKIES ARE GETTING SHOWERS AND
THUNDERSTORMS THIS AFTERNOON AS AN UPPER LEVEL DISTURBANCE
INTERACTS WILL MONSOONAL MOISTURE. RAIN WILL BE HEAVY AT TIMES AND
MAY LEAD TO FLASH FLOODING.
SCATTERED TO ISOLATED SHOWERS WILL SPREAD ACROSS CALIFORNIA AND
THE GREAT BASIN REGION AS A SLOW-MOVING UPPER LOW APPROACHES THE
WEST COAST. A SLOW-MOVING UPPER LOW OFF THE CALIFORNIA COAST
SHOULD GIVE WAY TO SCATTERED TO ISOLATED SHOWER ACTIVITY ACROSS
PORTIONS OF CALIFORNIA AND THE CENTRAL GREAT BASIN EARLY THIS
WEEK. THE HIGHEST RAINFALL AMOUNTS ARE FORECAST FOR THE SIERRA
NEVADA MOUNTAIN RANGE.

AFTERNOON THUNDERSTORMS WILL DEVELOP ALONG THE CENTRAL AND EASTERN
GULF COAST OVER THE NEXT FEW DAYS. PRECIPITATION AMOUNTS ARE
EXPECTED TO INCREASE AS AN INVERTED TROUGH PUSHES EASTWARD TOWARD
THE EAST COAST OF FLORIDA. EXPECT MUCH COOLER TEMPERATURES BEHIND
THE COLD FRONT AS IT SWEEPS EASTWARD.  MEANWHILE, WARMER THAN
NORMAL TEMPERATURES WILL OCCUR IN THE PACIFIC NORTHWEST AND
NORTHERN ROCKIES.

CAMPBELL





GRAPHICS AVAILABLE AT
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