413
FOUS11 KWBC 051905
QPFHSD
PROBABILISTIC HEAVY SNOW AND ICING DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
205 PM EST THU MAR 5 2026
VALID 00Z FRI MAR 06 2026 - 00Z MON MAR 09 2026
..NORTHEAST
DAYS 1/2...
SHORTWAVE LOW OVER IA EARLY THIS MORNING WILL FURTHER WEAKEN INTO
A TROUGH AS IT SHIFTS TO THE EASTERN GREAT LAKES TODAY AND OVER
CENTRAL NEW ENGLAND TONIGHT. A 1040MB HIGH OVER QUEBEC RETAINS A
WEDGE OF COLD AIR OVER NEW ENGLAND THROUGH THE HUDSON VALLEY. WARM
AIR ADVECTION AHEAD OF THE LOW OVERRUNS THE COLD SETTING UP MIXED
PRECIP AND SOME ALL SNOW WELL INTO THE COLD SECTOR. SNOW PROBS ARE
QUITE LIMITED, GENERALLY AROUND 20% FOR >2" OVER SOUTHERN NH AND
FAR SOUTHERN MAINE WHICH DEPENDS ON HOW FAR PRECIP CAN SHIFT INTO
THE DRY HIGH. OTHERWISE, IT'S ICE GLAZE POTENTIAL FROM THE
CATSKILLS, BERKSHIRES INTO THE LITCHFIELD HILLS AND OVER THE
WORCESTER HILLS WHERE DAY 1 PROBS FOR >0.25" ARE 20-60%. PLENTY OF
PRECIP OCCURS WITH THIS SYSTEM, SO IT WILL COME DOWN TO SURFACE
TEMPERATURES AND EFFICIENCY OF FREEZING RAIN WITH RATE AND WIND
FACTORING IN. AS OF NOW THE POTENTIAL FOR 0.5" ICE IS LIMITED TO
THE BERKSHIRES WHERE THE PWPF IS AROUND 10%.
..CASCADES THROUGH THE ROCKIES
DAYS 1-3...
A DIGGING TROUGH OVER UTAH THIS EVENING WILL DIG DOWN TO AZ
TONIGHT AND PROMOTE LEE-SIDE SFC CYCLOGENESIS OVER EASTERN CO
TONIGHT (SEE NEXT SECTION FOR THAT PORTION OF THE SYSTEM).
CONCURRENTLY, BUILDING RIDGING IN THE NORTHEAST PACIFIC WILL FAVOR
NORTHWESTERLY FLOW INTO THE PAC NW WHICH WILL CONTINUE SOME LIGHT
TO MODEST SNOW FOR THE CASCADES EASTWARD TO ID AND WESTERN MT WHICH
WILL CONTINUE IN WAVES THROUGH SUNDAY. WPC PROBABILITIES FOR AT
LEAST 8 INCHES OF SNOW ARE >50% ABOVE ABOUT 5000FT OVER THE
CASCADES TO THE CENTRAL ID RANGES AND WESTERN/SOUTHWESTERN MONTANA.
THE UPPER TROUGH WILL FOCUS SOME LOCALLY HEAVIER SNOW (1-2"/HR
RATES) OVER THE UINTAS INTO COLORADO AS THE LOW MOVES EASTWARD
DIRECTLY OVER CENTRAL CO BEFORE WEAKENING AND STRETCHING
NORTHEASTWARD OVER THE PLAINS TOMORROW EVENING. WPC PROBABILITIES
FOR AT LEAST 8 INCHES OF SNOW ARE >50% ABOVE ABOUT 8000-9000FT. THE
HIGHEST TOTALS >12-18 INCHES ARE LIKELY IN THE SAN JUANS AND AT
ELEVATIONS > 10,000FT.
..CENTRAL/NORTHERN PLAINS AND UPPER MIDWEST
DAYS 1-2...
CONTINUATION OF THE UPPER TROUGH/LOW OVER THE ROCKIES WILL PROMOTE
LEE-SIDE SFC CYCLOGENESIS OVER EASTERN CO TONIGHT THAT TRACKS OVER
IOWA AND WISCONSIN FRIDAY AND NORTHERN MICHIGAN EARLY SATURDAY.
GUIDANCE REMAINS UNCERTAIN IN THE STRENGTH OF THIS LOW (E.G., GFS
STRONGER AND FARTHER NORTHWEST) AND ANY POTENTIAL TROWAL
DEVELOPMENT CONTINGENT UPON SAID STRENGTHENING. MIDDLE GROUND
APPROACH, FOR NOW, YIELDS GENERALLY LIGHT SNOW FOR THE NORTHERN
PLAINS TO THE UPPER MIDWEST BUT LIKELY WITH AN AREA OF HIGHER
TOTALS VIA BANDING AND ENHANCED FGEN IN THE REGION DESPITE THE
MARGINAL TEMPERATURES. INDIVIDUAL 12Z CAM GUIDANCE SHOWS SOME
SPOTTY 4-6" AMOUNTS BETWEEN NORTHERN NE THROUGH SD TO NORTHERN MN
BUT OTHERS SHOW NEXT TO NOTHING. WPC PROBABILITIES FOR AT LEAST 4
INCHES OF SNOW REMAIN LOW (10% OR LESS) BUT THE AREA BEARS
WATCHING.
MULLINAX/FRACASSO
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