Prognostic Meteorological Discussion
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FXUS01 KWBC 250839
PMDSPD

SHORT RANGE FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
338 AM EST SUN JAN 25 2015

VALID 12Z SUN JAN 25 2015 - 12Z TUE JAN 27 2015

...A CLIPPER SYSTEM WILL EVOLVE INTO A COASTAL STORM BRINGING SNOW
FROM THE OHIO VALLEY TO THE NORTHEASTERN STATES...

...WELL ABOVE NORMAL TEMPERATURES EXPECTED OVER THE CENTRAL U.S...

...WET WEATHER IS IN THE FORECAST FOR THE DESERT SOUTHWEST...


THE AMPLIFIED PATTERN ACROSS THE NATION WILL CONTINUE WHICH
FEATURES A BROAD UPPER TROUGH EXTENDING OVER THE EASTERN HALF OF
THE U.S. MEANWHILE, A REX BLOCK IS EXPECTED ACROSS THE WEST WHICH
INDICATES A RIDGE IS BOUNDED TO THE SOUTH BY A CLOSED UPPER LOW.

THE DEEP UPPER TROUGH STRETCHING FROM THE GREAT PLAINS EASTWARD TO
THE EASTERN SEABOARD WILL ALLOW A SERIES OF DISTURBANCES TO DIG
THROUGH THE OHIO/TENNESSEE VALLEYS AND EVENTUALLY INTO THE
MID-ATLANTIC. THE INITIAL SYSTEM WHICH SPREAD WINTRY PRECIPITATION
TO SECTIONS OF THE NORTHEAST IS DEPARTING INTO THE CANADIAN
MARITIMES. WHILE SNOW HAS ENDED ACROSS NEW ENGLAND, GUSTY WINDS
CONTINUE GIVEN THE STRENGTH OF THE SURFACE CYCLONE. IN ITS WAKE, A
VERY BRIEF LULL IN THE PATTERN IS NOTED WITH THE NEXT SYSTEM
CURRENTLY ADVANCING THROUGH THE MIDDLE MISSISSIPPI VALLEY. THIS
CLIPPER SYSTEM WILL INITIALLY BE RATHER MOISTURE DEPRIVED WHICH IS
THE TYPICAL NATURE OF THESE SYSTEMS. THIS SHOULD SPREAD AN AREA OF
2 TO 6 INCHES OF SNOW TO THE OHIO VALLEY. AS THE UPPER TROUGH
AMPLIFIES ACROSS THE LOWER TENNESSEE VALLEY ON SUNDAY EVENING, A
COASTAL LOW IS FORECAST TO DEVELOP WHICH WILL SIGNIFICANTLY
INCREASE THE MOISTURE AVAILABLE TO THE STORM. THIS WILL ULTIMATELY
RAISE THE SNOWFALL TOTALS ACROSS THE MID-ATLANTIC ALONG WITH THE
SOUTHERN HALF OF NEW ENGLAND. CURRENTLY, THE WPC WINTER WEATHER
DESK IS EXPECTING 4 TO 8 INCHES OVER THE MARYLAND PANHANDLE INTO
SOUTHERN PENNSYLVANIA WHILE A SWATH OF 6 TO 12 INCHES WILL BE
POSSIBLE FROM NEW JERSEY UP TO EASTERN MASSACHUSETTS. ALL AMOUNTS
ARE THROUGH TUESDAY MORNING WITH SNOW CONTINUING TO FALL ACROSS
THE UPPER MID-ATLANTIC AND NEW ENGLAND AFTERWARD. IN ADDITION TO
THE HEAVY SNOW PROSPECTS, A TIGHTENING PRESSURE GRADIENT WILL LEAD
TO GUSTY WINDS WHICH MAY BRING BLIZZARD CONDITIONS TO SECTIONS OF
THE AFFECTED AREA.

OVER THE CENTRAL U.S., EXPECT WELL ABOVE NORMAL TEMPERATURES TO
PREVAIL ACROSS NORTHERN ROCKIES ALONG WITH THE GREAT PLAINS
REGION. THIS IS IN RESPONSE TO A PERSISTENT DOWNSLOPE FLOW WHICH
WILL SIGNIFICANT WARM THE SURFACE TEMPERATURES EAST OF THE HIGHER
TERRAIN. THE CURRENT FORECAST ANOMALIES SUGGEST READINGS OF 20 TO
30 DEGREES ABOVE NORMAL WHICH WOULD TRANSLATE TO HIGHS NEARING 70
ACROSS THE CENTRAL HIGH PLAINS ON MONDAY.

ELSEWHERE IN THE NATION, A SECONDARY CLIPPER SYSTEM IS EXPECTED TO
CROSS THE UPPER GREAT LAKES SPREADING LIGHT SNOWFALL ACCUMULATIONS
ON MONDAY. LOOKING TO THE SOUTHWESTERN STATES, THE EARLIER
MENTIONED CLOSED LOW WILL LIFT NORTHWARD FROM THE SUBTROPICAL EAST
PACIFIC. ENHANCED MOISTURE COMBINED WITH STRONG VERTICAL LIFT WILL
SPREAD A HEFTY BATCH OF RAINFALL TO THE DESERT SOUTHWEST ON MONDAY
AND TUESDAY. WIDESPREAD RAINFALL AMOUNTS OF 0.25 TO 0.50 INCHES
ARE LIKELY WITH HEAVIER AMOUNTS IN THE LOCAL TERRAIN.


RUBIN-OSTER


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




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