Time and Day: 0830 Sunday
The Snapshot: One more dry and mild day today,
increasing clouds and heavy precipitation (snow turning to rain) Monday night.
The Science: Another dry and mild day today with a
strong inversion and cold east winds at pass level. At 8:30 it’s 12 degrees in
the base area (4,060’) and 32 at the top of Skyline (5,280’). The high pressure
ridge axis should drift over Washington during this afternoon bringing mostly
sunny skies and warm temperatures above the inversion and on the west slopes of
the Cascades.
As the high pressure moves east on Monday, warming
temperatures and increasing clouds will portend the change in synoptic pattern.
A strong SW oriented jet stream will begin to take shape and direct a plume of
moisture (Atmospheric River) into Washington State and Southern BC. Precip will
likely begin as snow Monday afternoon, but should transition to all rain by
Tuesday. These weather events are somewhat tricky with warm, moist air
overriding very cold air in place. We could see higher snow amounts before the
transition early Tuesday morning.
Tuesday looks to be a wet, warm, stormy day. Heavy
precipitation and high SW winds with high (7,000’) freezing levels will make
for sporty conditions.
The Long Range: Heavy rain and warm temperatures
continue Wednesday before a cold trough enters the region Wednesday night,
dropping freezing levels back to Pass level and returning precipitation to
snow. Total water amounts for the 72 hour period ending Wednesday night look to
be around 5-6”. When things cool off Wednesday night, a return to light to
moderate snow should finish out the week.
|
Precipitation Ending at 4am:
Today 24hr water = 0 Snow = 0
Tomorrow’s 24hr water = 1.5” Snow = 2-4”
Trend and Timing:
Precip should hold off at Stevens Pass
until the afternoon (1-4pm) on Monday. It should begin as snow, but transition
to rain all the way to ridgetops by Monday night/very early Tuesday morning.
|
|
|
|
24hr temperature
ending at 4 am tomorrow:
Low: 10 (in base area) High: 36 (on upper
mountain)
Free Air Freezing level: 6,000’ (below
freezing from mid-mountain down)
Trend and Timing:
In terrain above the inversion layer
temperatures should warm nicely during the day. Base area temperatures will
remain in the teens through Monday morning.
|
|
|
|
24hr Winds (mph) ending at 4 am tomorrow:
Base: E 5-10
Ridge Top: Variable 5-15
Trend and Timing:
Ridgetop winds have been shifting from
east to SW, along with dramatic swings in temperature. Speeds should remain
light to moderate through Monday morning.
DV
|
No comments:
Post a Comment