Prognostic Meteorological Discussion
Issued by NWS

000
FXUS01 KWBC 220842
PMDSPD

SHORT RANGE FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
442 AM EDT WED MAY 22 2013

VALID 12Z WED MAY 22 2013 - 12Z FRI MAY 24 2013

...A SLOW-MOVING COLD FRONT WILL BE THE FOCUS FOR HEAVY RAIN AND A
THREAT OF SEVERE WEATHER TODAY AND THURSDAY...

...MUCH COOLER CONDITIONS FOR THE PACIFIC NORTHWEST...WITH
SCATTERED CONVECTION AND HIGH-ELEVATION SNOWFALL POSSIBLE THROUGH
THURSDAY...

A SLOW-MOVING UPPER TROUGH AND ITS ASSOCIATED SURFACE COLD FRONT
EDGES SLOWLY EASTWARD ACROSS THE EASTERN HALF OF THE US DURING THE
NEXT FEW DAYS...REACHING THE ATLANTIC COAST ON FRIDAY MORNING.
WARM HUMID AIR AHEAD OF THE FRONT...COURTESY OF A SOUTHERLY FLOW
OFF THE GULF OF MEXICO WILL ALLOW SHOWERS AND THUNDERSTORM
DEVELOPMENT TO PRODUCE LOCALLY HEAVY RAINFALL AND THE THREAT OF
SEVERE WEATHER FOR THE OHIO VALLEY TODAY AND TONIGHT. THESE
CONDITIONS WILL TRANSLATE TO THE EAST COAST ON THURSDAY AND
THURSDAY EVENING. PLEASE REFER TO THE STORM PREDICTION CENTER FOR
THE LATEST INFORMATION AND UPDATES ON THE SEVERE WEATHER POTENTIAL
THROUGH THURSDAY NIGHT.

OUT WEST...A DEEP PACIFIC COLD FRONT WILL SLOWLY MIGRATE EASTWARD
ACROSS THE INTERMOUNTAIN WEST...WITH LOCALIZED SNOWFALL POSSIBLE
ACROSS THE WASHINGTON CASCADES AND OLYMPIC MOUNTAINS. ACROSS THE
NORTHERN ROCKIES AND LEE OF THE CASCADES...GUSTY WINDS...SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS WILL ACCOMPANY THE FRONT WHICH
SURGES TO THE CONTINENTAL DIVIDE TONIGHT AND EARLY THURSDAY. THIS
FRONT THEN STALLS ALONG THE DIVIDE UNTIL LATE THURSDAY NIGHT INTO
FRIDAY MORNING. WITH AN EASTERLY FLOW FROM THE PLAINS OVER RUNNING
THE SLOWING FRONT FROM CENTRAL MONTANA INTO SOUTHERN WYOMING...
ADDITIONAL PRECIPITATION IS EXPECTED TO DEVELOP EAST OF THE DIVIDE.

VOJTESAK

GRAPHICS AVAILABLE AT WWW.WPC.NCEP.NOAA.GOV
$$