Quantitative Precipitation Forecast
Issued by NWS

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29
372
FOUS11 KWBC 110939
QPFHSD

PROBABILISTIC HEAVY SNOW AND ICING DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
438 AM EST THU FEB 11 2016

VALID 12Z THU FEB 11 2016 - 12Z SUN FEB 14 2016

...GREAT LAKES...

DEEP NORTHWESTERLY TO WEST-NORTHWESTERLY FLOW...ALONG WITH STEEP
LAPSE RATES WILL CONTINUE TO SUPPORT WIDESPREAD LAKE EFFECT SNOWS
THE NEXT SEVERAL DAYS.  INITIALLY THE HEAVIEST SNOW WILL BE ACROSS
PORTIONS OF THE EASTERN U.P. AND NORTHWESTERN LOWER PENINSULA OF
MI AND ALONG THE SOUTHEASTERN SHORES OF LAKES ERIE AND ONTARIO.
BY LATE THURSDAY INTO FRIDAY...THE MEAN FLOW IS EXPECTED TO BACK
FURTHER TO THE WEST AHEAD OF A DEEP LOW DROPPING ACROSS HUDSON
BAY...SHIFTING THE FOCUS FOR HEAVY ACCUMULATIONS FURTHER TO THE
NORTH ALONG THE EASTERN SHORES OF THE LOWER LAKES AND FURTHER TO
THE EAST ALONG THE U.P.  BY LATE FRIDAY INTO SATURDAY...THE MEAN
FLOW IS EXPECTED TO ONCE AGAIN TURN THE NORTHWEST AS A
WELL-DEFINED SHORTWAVE DIGS SOUTH OF THE UPPER LOW...PIVOTING
ACROSS THE LAKES INTO THE NORTHEAST AS MODELS SHOW THE UPPER LOW
CONTINUING ITS SOUTHEASTERLY TRACK...REACHING NORTHERN NEW ENGLAND
BY THE END OF THE PERIOD.  MINIMAL ADJUSTMENTS TO CONTINUITY.


...PACIFIC NORTHWEST/NORTHERN ROCKIES...

PERSISTENT ONSHORE FLOW AHEAD OF AN APPROACHING UPPER TROUGH WILL
FUEL WIDESPREAD PRECIPITATION ACROSS THE PACIFIC NORTHWEST AND
NORTHERN ROCKIES THIS WEEKEND.  ANOMALOUSLY WARM CONDITIONS WILL
INITIALLY KEEP ANY SNOW CONFINED TO THE HIGHEST PEAKS...BUT AS
SHORTWAVE ENERGY EMBEDDED WITHIN THE BASE OF THE TROUGH SPREADS
INLAND...SUPPRESSING THE RIDGE CURRENTLY IN PLACE AND LOWERING
SNOW LEVELS ACROSS THE WESTERN U.S....HEAVY SNOWS WILL BECOME MORE
LIKELY ACROSS THE OLYMPICS...NORTHERN CASCADES AND THE ROCKIES OF
NORTHERN ID...NORTHWESTERN MT...AND NORTHWESTERN WYOMING.


...NORTHERN HIGH PLAINS...

LOW LEVEL WARM AIR...MOISTURE ADVECTION AHEAD OF A SHORTWAVE
ENERGY EJECTING OUT INTO THE PLAINS...ALONG WITH LOW-MID LEVEL
FRONTOGENESIS SHOULD SUPPORT A SWATH OF LIGHT TO MODERATE SNOWS
ACROSS PORTIONS OF EASTERN MONTANA INTO THE DAKOTAS ON SATURDAY.


...EASTERN NORTH CAROLINA...

WEAK MID-LEVEL ENERGY ROUNDING THE BASE OF A BROAD TROUGH IN THE
EAST WILL HAVE THE POTENTIAL TO PRODUCE A WINTRY MIX OF
PRECIPITATION AS IT STREAKS OFFSHORE AND SPINS UP A SURFACE LOW
OFF THE CAROLINA COAST ON FRIDAY.  LATEST THERMAL PROFILES WOULD
SUPPORT AN AXIS OF SNOW/SLEET...AND MAYBE EVEN FREEZING
RAIN...ACROSS EASTERN NORTH CAROLINA.  HOWEVER...SPREAD IN
ENSEMBLE MEMBERS AND RUN-TO-RUN CHANGES IN DETERMINISTIC GUIDANCE
SUGGESTS THERE IS STILL A LOT OF UNCERTAINTY IN THE EXACT DETAILS
OF THE FORECAST.

...MAINE...

AN INVERTED SURFACE TROUGH EXTENDING BACK FROM A LOW LIFTING INTO
THE CANADIAN MARITIMES COULD HELP FOCUS AN AREA OF MODERATE TO
HEAVY SNOW ACROSS PORTIONS OF MAINE ON SATURDAY.  THE WPC FORECAST
STARTED WITH A NON-NAM COMPROMISE.


THE PROBABILITY OF SIGNIFICANT ICING IS LESS THAN 10 PERCENT.

GERHARDT

$$





USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.