000
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
$$
000
FXUS01 KWBC 220842
PMDSPD
SHORT RANGE FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
442 AM EDT WED MAY 22 2013
VALID 12Z WED MAY 22 2013 - 12Z FRI MAY 24 2013
...A SLOW-MOVING COLD FRONT WILL BE THE FOCUS FOR HEAVY RAIN AND A
THREAT OF SEVERE WEATHER TODAY AND THURSDAY...
...MUCH COOLER CONDITIONS FOR THE PACIFIC NORTHWEST...WITH
SCATTERED CONVECTION AND HIGH-ELEVATION SNOWFALL POSSIBLE THROUGH
THURSDAY...
A SLOW-MOVING UPPER TROUGH AND ITS ASSOCIATED SURFACE COLD FRONT
EDGES SLOWLY EASTWARD ACROSS THE EASTERN HALF OF THE US DURING THE
NEXT FEW DAYS...REACHING THE ATLANTIC COAST ON FRIDAY MORNING.
WARM HUMID AIR AHEAD OF THE FRONT...COURTESY OF A SOUTHERLY FLOW
OFF THE GULF OF MEXICO WILL ALLOW SHOWERS AND THUNDERSTORM
DEVELOPMENT TO PRODUCE LOCALLY HEAVY RAINFALL AND THE THREAT OF
SEVERE WEATHER FOR THE OHIO VALLEY TODAY AND TONIGHT. THESE
CONDITIONS WILL TRANSLATE TO THE EAST COAST ON THURSDAY AND
THURSDAY EVENING. PLEASE REFER TO THE STORM PREDICTION CENTER FOR
THE LATEST INFORMATION AND UPDATES ON THE SEVERE WEATHER POTENTIAL
THROUGH THURSDAY NIGHT.
OUT WEST...A DEEP PACIFIC COLD FRONT WILL SLOWLY MIGRATE EASTWARD
ACROSS THE INTERMOUNTAIN WEST...WITH LOCALIZED SNOWFALL POSSIBLE
ACROSS THE WASHINGTON CASCADES AND OLYMPIC MOUNTAINS. ACROSS THE
NORTHERN ROCKIES AND LEE OF THE CASCADES...GUSTY WINDS...SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS WILL ACCOMPANY THE FRONT WHICH
SURGES TO THE CONTINENTAL DIVIDE TONIGHT AND EARLY THURSDAY. THIS
FRONT THEN STALLS ALONG THE DIVIDE UNTIL LATE THURSDAY NIGHT INTO
FRIDAY MORNING. WITH AN EASTERLY FLOW FROM THE PLAINS OVER RUNNING
THE SLOWING FRONT FROM CENTRAL MONTANA INTO SOUTHERN WYOMING...
ADDITIONAL PRECIPITATION IS EXPECTED TO DEVELOP EAST OF THE DIVIDE.
VOJTESAK
GRAPHICS AVAILABLE AT WWW.WPC.NCEP.NOAA.GOV
$$
000
FXUS01 KWBC 212017
PMDSPD
SHORT RANGE FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
417 PM EDT TUE MAY 21 2013
VALID 00Z WED MAY 22 2013 - 00Z FRI MAY 24 2013
...A SLOW MOVING COLD FRONT WITH SEVERAL LOW PRESSURE SYSTEMS WILL
PRODUCE HEAVY RAIN...A THREAT OF FLASH FLOODING AND CONTINUED
SEVERE WEATHER FOR THE NEXT COUPLE DAYS...
...MUCH COOLER CONDITIONS WILL AFFECT THE NORTHWESTERN CORNER OF
THE NATION WITH SCATTERED SHOWERS AND HIGH ELEVATION SNOW THAT
WILL PERSIST INTO THURSDAY...
...A STRONG PUSH OF COOLER AIR WILL MAKE ITS WAY ACROSS THE UPPER
MISSISSIPPI VALLEY INTO THE MIDWEST AND OHIO VALLEY BY THURSDAY...
COOL WEATHER WILL CONTINUE OVER THE NATIONS MIDSECTION AS 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. WARM HUMID AIR WILL COVER THE EASTERN US AND FLOW OFF
THE GULF OF MEXICO WILL PROVIDE LOTS OF MOISTURE IN GENERATING
SHOWERS AND THUNDERSTORMS NEAR AND AHEAD OF THE FRONT. FARTHER
NORTH...CLOUDY AND COOL CONDITIONS WITH RAIN AND RAIN SHOWERS WILL
COVER MUCH OF THE UPPER MIDWEST ACROSS NORTHERN NEW ENGLAND.
HOWEVER...MOST OF THE HEAVY THUNDERSTORM AND A POSSIBILITY OF MORE
SEVERE WEATHER WILL OCCUR ALONG AND EAST OF THE ADVANCING COLD
FRONT. ORGANIZED CONVECTIVE SYSTEMS WILL LIKELY PRODUCE LOCALIZED
FLASH FLOODING WHILE SEVERE WEATHER IS A RISK THIS EVENING ACROSS
EASTERN TEXAS INTO THE LOWER MISSISSIPPI VALLEY. THESE RISKS WILL
LIKELY PUSH SLOWLY EASTWARD OVER THE NEXT COUPLE DAYS. PLEASE
REFER TO THE STORM PREDICTION CENTER FOR THE LATEST INFORMATION
AND UPDATES ON ANY TORNADO AND SEVERE WEATHER THREATS.
WITH THE EXCEPTION OF NORTHERN NEW ENGLAND WHERE CLOUDY...COOL AND
OCCASIONALLY RAINY CONDITIONS WILL OCCUR OVER THE NEXT COUPLE
DAYS...MUCH OF THE EAST AND SOUTHEAST COASTS...INCLUDING FLORIDA
WILL EXPERIENCE WARM AND HUMID CONDITIONS WITH MOSTLY SCATTERED
SHOWERS AND LOCALIZED THUNDERSTORMS ESPECIALLY IN THE LATE
AFTERNOON AND EVENING. BY THURSDAY...AS THE UPPER TROUGH/SURFACE
FRONT NEARS THE EAST COAST...A SECONDARY SURGE OF COOLER AIR WILL
BE MOVING SOUTHWARD ACROSS THE MIDWEST AND SHOULD HELP CLEAR OUT
MUCH OF THE CENTRAL AND NORTHERN PLAINS/MIDWEST AND OHIO VALLEY
BEFORE HEADING TOWARD THE EAST COAST LATE IN THE WEEK. RELATIVELY
COOL...COMFORTABLE CONDITIONS WILL FOLLOW IN THE WAKE OF THIS
SECONDARY COOL OUTBREAK.
AN IMPRESSIVE DEEP TROUGH OVER THE PACIFIC NORTHWEST WILL CONTINUE
TO PUSH A COLD FRONT SLOWLY EASTWARD ACROSS THE INTERMOUNTAIN
WEST. SNOW LEVELS WILL FALL TO ABOUT 3500 FEET ACROSS THE
WASHINGTON CASCADES AND OLYMPIC MOUNTAINS WHERE SEVERAL INCHES OF
SNOW WILL ACCUMULATE. THIS DEEP UPPER LOW WILL LIKELY REMAIN OVER
THE NORTHWEST FOR THE NEXT SEVERAL DAYS AND WILL RESULT IN
BREEZY...COOL AND SHOWERY CONDITIONS TO CONTINUE.
KOCIN
GRAPHICS AVAILABLE AT WWW.WPC.NCEP.NOAA.GOV
$$
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