Prognostic Meteorological Discussion
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FXUS02 KWBC 120658
PMDEPD

EXTENDED FORECAST DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
158 AM EST FRI FEB 12 2016

VALID 12Z MON FEB 15 2016 - 12Z FRI FEB 19 2016

...STORMY E-CENTRAL US FLOW EARLY NEXT WEEK SWITCHES TO THE
W-CENTRAL US LATER WEEK...

THE WPC MEDIUM RANGE PRODUCT SUITE WAS PRIMARILY DERIVED FROM A 12
UTC NAEFS/ECMWF ENSEMBLE MEANS AND CONTINUITY COMPOSITE IN LUE OF
MORE VARIED DETERMINISTIC MODELS.

IN THIS WPC BLEND...OPTED TO LEAN MORE ON THE NAEFS MEAN MON INTO
WED DURING A PERIOD OF ACTIVE CENTRAL TO ERN US WEATHER AS IT
OFFERED BETTER CONTINUITY. FORECAST CONFIDENCE IS GOOD WITH GREAT
LAKE EFFECT SNOWS WITH SYSTEM PASSAGE...BUT COMPLICATED STREAM
SEPARATION/PHASINGS AND EMBEDDED SYSTEM EMPHASIS/TIMINGS MAKE THE
LEAD ERN US FORECAST MORE TRICKY WITH AIRMASS TRANSITION.
INCREASINGLY FAVORABLE GULF OF MEXICO THEN ATLANTIC INFLOW INTO AN
AMBIENT BUT RECEDING ERN US COLD AIRMASS OFFERS AMPLE POTENTIAL
FOR A WINTERY SNOW-ICE-RAIN MESS IN A PATTERN WITH WIDESPREAD
HEAVIER PCPN.

LATER OPTED UPSTREAM TO LEAN THE WPC GUIDANCE BLEND HEAVIER ON THE
MORE AMPLIFIED ECMWF ENSEMBLE MEAN IN AN ACTIVE WEATHER FLOW FOR
THE WRN TO CENTRAL US LATER WED INTO THU/NEXT FRI CONSIDERING
SUPPORTIVE UPSTREAM FLOW AND GUIDANCE TRENDS. CLUSTERING HAS
IMPROVED OVER THE PAST FEW DAYS. THIS SOLUTION IS HIGHLIGHTED WITH
ADVANCE OF DYNAMIC MID-UPPER LEVEL TROUGHING AND LEADING SURFACE
SYSTEM/WIDESPREAD PCPN TRANSLATION ACROSS THE WEST COAST THEN
INTERMOUNTAIN WEST TO THE ROCKIES/PLAINS WED-NEXT FRI...WITH
COASTAL HEAVY RAINS AND INLAND SNOWS FURTHER ENHANCED BY FAVORED
TERRAIN.

FORECAST CONFIDENCE IS NEAR NORMAL WITH THE LARGER SCALE PATTERN
EVOLUTION ALOFT...BUT LESS THAN NORMAL WITH STREAM/EMBEDDED SYSTEM
INTERACTIONS AND THE ASSOCIATED LOWER ATMOSPHERIC RESPONSE AND
LOCAL WEATHER FOCUS DURING THE 3-7 DAY TIME FRAME.

SCHICHTEL

$$




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