Quantitative Precipitation Forecast
Issued by NWS

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000
FOUS11 KWBC 282111
QPFHSD

PROBABILISTIC HEAVY SNOW AND ICING DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
411 PM EST WED JAN 28 2015

VALID 00Z THU JAN 29 2015 - 00Z SUN FEB 01 2015


DAYS 1 THROUGH 3...

...GREAT LAKES/OH VALLEY INTO NORTHEAST...

A SHORT WAVE EMERGING OUT INTO THE CENTRAL PLAINS THIS AFTN WILL
EVENTUALLY BEGIN TO TEAM UP WITH MULTIPLE DIGGING STREAMS... UPPER
DYNAMICS FROM THE NRN AND ARCTIC JETS... TO INDUCE A COUPLE OF
SURFACE WAVES. THE MAIN WAVE WILL SWEEP FROM THE CENTRAL PLAINS TO
NRN NEW ENGLAND BEFORE RE-FORMING AND PHASING OFF THE COAST OF NEW
ENGLAND BY FRI EVENING INTO SAT. THE GUIDANCE INDICATES OVERALL
NARROW SPREAD WITH THIS FCST SCENARIO... INCLUDING THE DEEP
CYCLOGENESIS ON SAT JUST OFFSHORE OF NEW ENGLAND. A 50KT LOW LEVEL
JET AHEAD OF A PROGRESSIVE SURFACE COLD FRONT WILL FUNNEL NORTH
VERY MODEST .50 TO AOA 1 INCH PWS INTO THE OH VALLEY/GREAT LAKES
ON THURS AND NORTHEAST ON FRI. THIS SHOULD RESULT IN WARM
ADVECTION AND OVERRUNNING WITH 70 TO 90 PERCENT MEAN LAYER RH
SLIDING THROUGH THE AREA FOR LIGHT TO MDT SNOW WITH PERHAPS AT THE
START OF THURS SOME LIGHT FREEZING DRIZZLE. THE MAIN THREAT ON
THURS WILL BE 1 TO 3 INCHES OF SNOW FROM MI INTO NERN OH/WRN PA
AND WRN NY WITH LOCALLY HIGHER AMOUNTS IN NORTH CENTRAL LOWER MI
AND PERHAPS LIGHT ICING FROM SERN WI/NRN IL TO NWRN OH. THEN THE
ENTIRE PRECIP SHIELD SURGES INTO NEW ENGLAND FOR FRI WITH 2-4 INCH
AMOUNTS ANTICIPATED ACROSS MUCH OF NY STATE INTO NEW ENGLAND.
DURING THE DAY FRI... BETTER ATLANTIC MOIST INFLOW BEGINS TO FOCUS
ALONG AN INVERTED TROUGH/DRAPED FRONT OVER MAINE FOR ENHANCED
SNOWFALL AMOUNTS. THEN FINALLY ON SAT... RAPID SURFACE
CYCLOGENESIS JUST OFFSHORE OF NEW ENGLAND WILL RESULT IN A
FLOURISHING DEFORMATION ZONE IN AN AREA PRIME FOR STRONG DYNAMIC
COOLING... MEANING POSSIBLE SIGNIFICANT SNOWFALL AMOUNTS ACROSS
MAINE BACK INTO NH. WPC WENT WITH LOW AND MDT PROBS OF
4 INCHES ON THURS... 4 AND 8 INCH HVY SNOW PROBS ON FRI AND 4 TO
12 INCH PROBS ON SAT.


...SOUTHWEST/SOUTHERN ROCKIES/SOUTHERN PLAINS...

A RATHER AMPLIFIED WEAKNESS OFF THE WEST COAST... MAINLY CA...
WILL BEGIN TO ADVANCE EASTWARD TO BECOME A BIT MORE CONSOLIDATED
OVER CA ON THURS... PERHAPS CLOSE OFF A LARGE MID TO UPPER LOW
OVER SRN CA/DESERT SW COME FRI AND DRIFT DOWNSTREAM TOWARD AZ/NRN
MEXICO ON SAT. THIS WILL RESULT IN A STEADY INCREASE OF SRN STREAM
AND SUBTROPICAL MOISTURE SPREADING NORTH AND EAST OVER TIME AND BY
FRI/SAT A POTENTIALLY LARGE SYNOPTIC SCALE RAIN/MTN SNOW EVENT
BLEEDING OUT INTO THE SRN HIGH PLAINS. FOR THE MOST PART... THE
GUIDANCE SHOWS THIS SCENARIO WITH A FEW WRINKLES IN THE FCST BUT
MOST INDICATE IDEAL SWRLY UPPER DIFLUENT UPPER FLOW SETTING UP FOR
STRONG OROGRAPHICS AND HEAVY SNOWFALL FOR PARTS OF THE FOUR
CORNERS TERRAIN ON FRI. THE FOCUS POINT APPEARS AT THE MOMENT TO
BE NM INTO SWRN CO/SRN UT... AS A MAMMOTH COLD SURFACE RIDGE
DOWNSTREAM WEDGES IN FROM THE MIDWEST. ITS THIS RIDGE WHICH COULD
PRESENT PROBLEMS ON SAT... AS THE DENSE AIR MASS UNDERCUTS THE
ARRIVAL OF SOME OF THIS PAC MOISTURE FEED FOR POSSIBLE SNOW
EXTENDING OUT INTO ERN NM AND TX/OK PANHANDLES ALONG WITH A VERY
SLIGHT CHANCE ACROSS KS/NE OR ON THE VERY NRN PERIPHERY OF THE
EXPANDING PRECIP SHIELD OVER THE CENTRAL/SRN PLAINS. WPC WENT
AHEAD WITH 4 AND 8 INCH HEAVY SNOW PROBS EACH DAY BASED ON A BLEND
OF THE GUIDANCE... FOCUSING ON THE NM TERRAIN AND SAN JUANS OF
SWRN CO/SRN WASATCH OF UT ON FRI AND A CONTINUATION OF MTN SNOW
OVER NM/SWRN CO INTO THE SANGRE DE CRISTO RANGE AND DOWN THE
FOOTHILLS INTO ERN NM AND TX/OK PANHANDLES.


MUSHER



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