Quantitative Precipitation Forecast
Issued by NWS

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FOUS11 KWBC 012129
QPFHSD

PROBABILISTIC HEAVY SNOW AND ICING DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
428 PM EST SUN MAR 01 2015

VALID 00Z MON MAR 02 2015 - 00Z THU MAR 05 2015


...NORTHERN MID-ATLANTIC/NORTHEAST...

A WEAK MID-LEVEL DISTURBANCE OVER THE OH VALLEY WILL STREAM TOWARD
COASTAL NEW ENGLAND BY MON MORNING AND TEAM WITH AN AMPLIFIED BUT
PROGRESSIVE NRN STREAM TROUGH FOR RAPID CYCLOGENESIS. BEFORE
THEN... DESPITE THE RELATIVE WEAK NATURE OF THE IMPULSE... ENOUGH
MOISTURE FLUX REMAINS PRESENT FOR CONTINUED FREEZING RAIN/MIX
ACROSS THE MID-ATL REGION THIS EVENING/LATE TONIGHT WITH
WIDESPREAD MDT TO HEAVY SNOWFALL ACROSS PARTS OF NEW ENGLAND.

THE RETREATING HIGH OVER THE EAST AND NOT A VERY STRONG WARM NOSE
WITH THE FLAT SYSTEM... HAS ALLOWED ARCTIC/SHALLOW AIR MASS TO
HOLD ON VERY STRONG AND WIDESPREAD FROZEN PRECIP OVER PARTS OF THE
SOUTHEAST AND ACROSS THE ENTIRE MID-ATL REGION. THE BIGGEST
PROBLEM AREA CURRENTLY IS ACROSS THE NRN MID-ATL REGION FROM RIC
NORTHWARD. THE ERODING OF THIS SHALLOW AIR MASS SHOULD GRADUALLY
CONTINUE FROM SOUTH AND WEST TO NORTH AND EAST THROUGH THE EVENING
INTO LATE TONIGHT... AN ADDITIONAL .10 TO.20 ICE ACCRETIONS WILL
BE POSSIBLE FROM BWI NORTH AND EAST INTO SOUTHEAST PA/NJ.

MEANWHILE... POCKETS OF 4 TO 6 INCH HEAVY SNOWFALL AMOUNTS WILL BE
POSSIBLE OVERNIGHT SUN INTO MON MORNING/MIDDAY ACROSS THE FAVORED
NEW
ENGLAND TERRAIN AND POSSIBLE AXIS OF SIMILAR AMOUNTS ACROSS SRN
NEW ENGLAND FROM CT TO COASTAL MA.

...FOUR CORNERS/CENTRAL ROCKIES TO UPPER MIDWEST/OH VALLEY AND
NORTHEAST/NORTHERN MID-ATL...

A CLOSED UPPER LOW ALONG THE ACTIVE SRN BRANCH WILL DRIVE AN
ADDITIONAL TWO DAYS OF TERRAIN HEAVY SNOWFALL ACROSS THE FOUR
CORNERS REGION INTO THE CENTRAL ROCKIES BEFORE THE ENTIRE SHORT
WAVE EJECTS OUT INTO THE UPPER MIDWEST ON TUES AND NEW ENGLAND ON
WED... AHEAD OF ANOTHER DIGGING SHOT OF ARCTIC AIR... FOR
WIDESPREAD WINTER WEATHER ACROSS THE UPPER MS VALLEY/GREAT LAKES
AND OH VALLEY INTO THE NORTHEAST

THE HEAVIEST SNOWFALL ACCUMULATIONS OF THE THREE DAYS WILL OCCUR
ON MON ACROSS THE FOUR CORNERS REGION. INCREASING SWRLY UPPER
DIFLUENT 700-500MB FLOW WILL CONSUME THE FOUR STATES FOR IDEAL
OROGRAPHICS. A MOIST COMPONENT WILL RESULT IN VERY HEAVY SNOWS
FROM NWRN AZ/SRN UT WASATCH BUT ALSO HEAVY MTN SNOWS FOR WRN CO...
WHERE WPC WENT WITH PROBS OF A FOOT OR MORE.

THE SYSTEM BREAKS DOWN AND SHOOTS INTO THE CENTRAL PLAINS COME
TUES MORNING... AHEAD OF A DIGGING NRN STREAM TROUGH AND ARCTIC
COLD FRONT. THIS SHOULD RESULT IN A SURFACE WAVE SLIDING FROM NRN
KS/SRN NE TO LOWER MI ON TUES WHILE TAPPING INTO INCREASING
AVAILABLE GULF OF MEXICO MOISTURE FOR A FLOURISHING PRECIP
SHIELD... WHILE AN ARCTIC COLD FRONT CREEPS IN FROM THE NORTH AND
WEST. THE RESULTANT BASED ON A BLEND OF THERMAL PROFILES OF THE
GFS/ECMWF SUGGESTS HEAVY SNOWFALL POTENTIAL FROM NRN IA/SOUTH
CENTRAL MN INTO WI/MI WITH A POSSIBLE TRANSITION ZONE THROUGH THE
OH VALLEY INTO THE CENTRAL APPALACHIANS AND PERHAPS NRN MID-ATL
REGION. MEANWHILE... ON THE TAIL END OF THE ARCTIC COLD FRONT
PLUNGING DOWN THE FRONT RANGE OF THE ROCKIES... EXPECT POSSIBLE
UPSLOPE SNOWFALL FROM MT/WY INTO CO.

FINALLY THE SRN STREAM SYSTEM AND ARCTIC FRONT WILL PUSH THROUGH
THE NORTHEAST EARLY WED FOR ANOTHER ROUND OF OF HEAVY SNOW AND
POSSIBLE ICING IS ANTICIPATED.

...SOUTHERN PLAINS INTO MID TO LOWER MS VALLEY AND OH/TN VALLEYS...

A POSSIBLE SIGNIFICANT WINTER WEATHER STORM WILL BE POSSIBLE ON
WED FROM THE SRN ROCKIES/PLAINS TO THE OH/TN VALLEYS AND CENTRAL
APPALACHIANS. SPLIT UPPER LEVEL FLOW ALOFT WILL ALLOW AN
AGGRESSIVE NRN STREAM TO ADVANCE THE NEXT ARCTIC INTRUSION SOUTH
THROUGH THE PLAINS AND PARTS OF THE MS VALLEY... WHILE A DYNAMIC
SRN STREAM CLOSED LOW WILL BREAK DOWN AS AN OPEN WAVE TROUGH AND
SHEAR THROUGH THE SOUTHWEST INTO THE SRN PLAINS. A TREMENDOUS AND
ANOMALOUS AMOUNT OF MOISTURE FROM THE GULF OF MEXICO AND SRN
BRANCH WILL STREAM UP/OUT AND GET UNDERCUT BY THE SHARP ARCTIC
THERMAL ZONE FOR A POSSIBLE WIDESPREAD ZONE OF SNOW AND FREEZING
RAIN. THE GUIDANCE SHOWS CONSIDERABLE SPREAD BUT ALL SUGGEST
SIGNIFICANT QPF ANTICIPATED INVOF THE BAROCLINIC ZONE. WPC
GENERALLY FOLLOWED A BLEND OF THE ECMWF/GFS ON QPF AND THERMAL
PROFILES FOR AN EXTENSIVE ZONE OF FREEZING RAIN PROBS FROM NORTH
TX NORTH AND EAST TO EAST CENTRAL TN/NRN AL AND HEAVY SNOW PROBS
FROM OK NORTH AND EAST THROUGH SRN MO/NRN AR INTO THE LOWER
PORTION OF THE OH VALLEY INTO THE CENTRAL APPALACHIANS. THIS IS
ALL BEFORE A POSSIBLE WAVE STREAMS EASTWARD FOR THURS. THIS FCST
IS HIGHLY FLUID AND LIKELY TO CHANGE AND EVOLVE OVER THE NEXT FEW
DAYS... PLEASE STAY TUNED.


MUSHER


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