116
FXUS01 KWBC 221946
PMDSPD
SHORT RANGE FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
345 PM EDT WED MAY 22 2013
VALID 00Z THU MAY 23 2013 - 00Z SAT MAY 25 2013
..LESS THAN A MONTH TIL SUMMER BUT
...THREAT OF SNOW CONTINUES FOR HIGH ELEVATIONS IN THE
NORTHWEST...AND EVEN A CHANCE FOR THE HIGHER ELEVATIONS OF THE
APPALACHIANS LATER FRIDAY!...
...SLOW MOVING FRONT IN THE EAST WILL SPREAD SHOWERS AND
THUNDERSHOWERS BEFORE MUCH COOLER AIR BEGINS TO MOVE SOUTH AND
EASTWARD FROM EASTERN CANADA ACROSS THE MIDWEST ACROSS THE EASTERN
US...
..VERY COOL CONDITIONS WILL REMAIN ACROSS THE PACIFIC NORTHWEST
A HIGHLY AMPLIFIED FLOW PATTERN FOR LATE MAY WILL ALLOW SNOW TO
FALL AT THE THE HIGHER ELEVATIONS OF THE NORTHWEST US OVER THE
NEXT COUPLE DAYS. A DEEP UPPER LOW WILL MOVE VERY SLOWLY EASTWARD
KEEPING VERY COOL CONDITIONS...NUMEROUS SHOWERS AND HIGHER
ELEVATION SNOW ACROSS THE NORTHWEST. WINTER WEATHER ADVISORIES ARE
CURRENTLY IN EFFECT ACROSS THE CASCADES...BLUE MOUNTAINS AND
ACROSS NW MONTANA.
ANOTHER TROUGH MOVING EASTWARD ACROSS THE MISSISSIPPI VALLEY TODAY
WILL ALSO MOVE SLOWLY EASTWARD. THIS SYSTEM WILL BE REINFORCED BY
A STRONG UPPER LEVEL TROUGH OVER EASTERN CANADA THAT WILL RESULT
IN A STRENGTHENING SYSTEM OVER THE EAST COAST BY FRIDAY. AS
COLDER AIR WORKS ITS WAY INTO THIS SYSTEM...THERE IS A CHANCE FOR
A VERY LATE SEASON SNOWFALL ACROSS THE HIGH ELEVATIONS OF WEST
VIRGINIA/WESTERN MARYLAND AND SW PENNSYLVANIA...PERHAPS ONE OF THE
LATEST OCCURRENCES ON RECORD IF IT OCCURS.
MEANWHILE...RAIN WILL FALL ACROSS THE UPPER MIDWEST OVER THE NEXT
COUPLE DAYS BEFORE COOLER DRIER AIR MOVES IN. OVER THE
SOUTHEAST...WARM HUMID AIR AND SCATTERED SHOWERS AND
THUNDERSHOWERS WILL DOMINATE THE NEXT SEVERAL DAYS. HEAVIER
SHOWERS AND THUNDERSTORMS ARE POSSIBLE LATER IN THE FORECAST OVER
THE MIDDLE ATLANTIC STATES TO NEW ENGLAND AS THE SHARPENING UPPER
TROUGH PROVIDES LIFT FOR ABUNDANT RAINFALL AND EVEN THE
POSSIBILITY OF SOME SEVERE WEATHER. SEE SPC DISCUSSIONS FOR MORE
DETAILED DISCUSSIONS OF THE THREAT FOR SEVERE WEATHER.
AS COOLER AIR MAKES ITS WAY SOUTHWARD ACROSS THE SOUTHERN
PLAINS...SOUTHEAST FLOW FROM THE GULF OF MEXICO WILL INCREASE THE
CHANCE FOR SHOWERS AND THUNDERSHOWERS ACROSS TEXAS INTO THE
SOUTHERN PLAINS ON THURSDAY INTO FRIDAY.
KOCIN
GRAPHICS AVAILABLE AT WWW.WPC.NCEP.NOAA.GOV
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page