489
FOUS11 KWBC 202027
QPFHSD
PROBABILISTIC HEAVY SNOW AND ICING DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
327 PM EST THU FEB 20 2025
VALID 00Z FRI FEB 21 2025 - 00Z MON FEB 24 2025
..COLORADO ROCKIES AND CENTRAL HIGH PLAINS
DAY 1...
SHORTWAVE TROUGH AXIS OVER UTAH THIS AFTERNOON WILL SHIFT EAST OVER
CO TONIGHT AND INTO WESTERN KS FRIDAY MORNING. WEAK JET STREAK
ALOFT AND PVA FROM THE TROUGH WILL PRODUCE WIDESPREAD DEEP LAYER
ASCENT TO SUPPORT SNOW OVER CO TONIGHT WITH BANDING EXTENDING EAST
OVER THE PALMER DIVIDE, THROUGH EASTERN CO AND INTO WESTERN KS LATE
TONIGHT INTO FRIDAY. DAY 1 SNOW PROBS FOR >6" AFTER 00Z ARE 40-80%
IN THE I-70 CORRIDOR OF NORTH-CENTRAL CO TERRAIN AND AROUND 30% ON
THE I-25 CORRIDOR OVER THE PALMER DIVIDE NEAR CASTLE ROCK.
PROBABILITIES FOR >2" SPREAD EAST ALONG I-70 TO LIMON, BUT GIVEN
THE BANDING POTENTIAL FROM UPPER FORCING, THERE IS POTENTIAL FOR
OVER AN INCH INTO KS.
..PACIFIC NORTHWEST TO THE NORTHERN ROCKIES
DAYS 2-3...
MID-LEVEL LOW PRESSURE PUSHES ACROSS THE QUEEN CHARLOTTE SOUND
FRIDAY EVENING WITH MOISTURE ADVECTION AND RELATIVELY SHORT-LIVED
MODERATE PRECIP TO THE SOUTH OVER THE PACIFIC NORTHWEST FRIDAY
NIGHT. A BROADER TROUGH APPROACHES THE PACIFIC NORTHWEST THIS
WEEKEND WITH HEAVIER PRECIP THEN EXPECTED SATURDAY AFTERNOON
THROUGH SUNDAY.
FOR FRIDAY NIGHT EXPECT SNOW LEVELS TO GRADUALLY RISE TO 5000 FT
ALONG THE WEST SIDE OF THE WA CASCADES WITH COLD AIR ENTRENCHED ON
THE EAST SIDE KEEPING SNOW LEVELS AROUND 2000FT. DAY 2 SNOW PROBS
FOR >6" ARE 50-80% FOR ONLY THE HIGHER WA CASCADES AND FAR NORTHERN
ID TERRAIN.
THE BROADER MOISTURE SURGE SATURDAY AFTERNOON BRINGS WIDESPREAD
6000-8000 FT SNOW LEVELS, KEEPING SIGNIFICANT SNOW ACCUMULATIONS
ABOVE CASCADES PASS LEVELS, WITH 6000FT SNOW LEVELS INLAND OVER THE
NORTHERN ROCKIES. DAY 3 SNOW PROBS FOR >6" ARE 40-80% ON THE HIGHER
WA CASCADES, WESTERN SAWTOOTHS, RANGES AROUND GLACIER NP, AND THE
TETONS. MODERATE PRECIP WILL CONTINUE OVER TERRAIN INTO SUNDAY
NIGHT.
JACKSON
...COLD KEY MESSAGES ARE IN EFFECT FOR MUCH OF THE SOUTHERN U.S. AS
LINKED BELOW...
HTTPS://WWW.WPC.NCEP.NOAA.GOV/KEY_MESSAGES/LATESTKEYMESSAGE_2.PNG
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