000
FOUS11 KWBC 160759
QPFHSD

PROBABILISTIC HEAVY SNOW AND ICING DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
359 AM EDT TUE MAR 16 2010

VALID 12Z TUE MAR 16 2010 - 12Z FRI MAR 19 2010

DAYS 1 AND 2...

THE PROBABILITY OF HVY SNOW AND/OR SIGNIFICANT ICING IS LESS THAN
10 PERCENT.

DAY 3

...NORTHERN ROCKIES...

THE MODELS HAVE COME INTO AGREEMENT ON THE IDEA THAT AN UPPER TROF
AND AN ASSOCIATED COLD FRONT WILL MAKE ITS WAY INLAND FROM THE ERN
NOPAC INTO THE NORTHWEST THURSDAY.  SNOWFALL AMOUNTS GENERALLY
APPEARS TO BE LIGHT UNTIL THE UPPER TROF REACHES THE NORTHERN
ROCKIES ON DAY 3.  AT THAT POINT...THE TROF AMPLIFIES AND INDUCES
LEE CYCLOGENESIS LATE ON DAY 3.  ONCE THIS HAPPENS...EXPECT
INCREASING COVERAGE OF SNOWFALL WITH SOME LOCALLY HEAVIER AMOUNTS.
 IT WOULD APPEAR THAT SNOWFALL AMOUNTS IN THE GFS ARE TOO HEAVY ON
DAY 3 CONSIDERING THAT PAC MOISTURE WILL BE DECREASING.
CONSEQUENTLY HPC MANUAL PROGS TENDED TO USE SNOWFALL AMOUNTS THAT
WERE CLOSER TO THE 00Z NAM WHILE ATTEMPTING TO KEEP GFS/ECMWF
POSITION AND SPEED.

THE PROBABILITY OF SIGNIFICANT ICING IS LESS THAN 10 PERCENT.

BANN
$$