0630 Thursday
The Snapshot: Light snow this morning
changing to mixed rain and then tapering off later today. Heavy rain and snow is expected Friday with
snow on Saturday.
The Science: A weak cold front will move
through the mountains today. This will produce light snow and rain. Warmer air advection from the SW will raise
freezing levels to near 5000’. A weak high-pressure
ridge passing to the south of Stevens Pass will break up the moisture stream
and allow more warm air to settle over the area. Freezing levels will be on the cusp of
allowing snow or rain until a stronger cold front moves through on Saturday and
then again on Sunday. The weekend storms
have a better chance of measurable snow than tomorrow’s storm.
4-7day
Long Range: More storms are
lining up to hit the PNW during the start of the week. A strong high-pressure ridge off the coast of
California will inch north during the start of next week. Models have a hard time agreeing on what
effect this will have to the PNW. So I
will leave that for the weekend forecasts.
|
24hr precipitation ending at 4am
tomorrow:
Water = .5 Snow = 1-2”
Trend and Timing:
Light snow will change to light rain this morning
with continuing showers throughout the day.
|
|
|
|
24hr temperature ending at 4am tomorrow:
Low: 30 High:
35
Freezing level: 4000 – 5000’
Freezing Level Trends and Timing
Freezing levels will rise to near 5000’
today. Cool east flow will help hold
surface temperatures to near freezing.
|
|
|
|
24hr Winds (mph) ending at 4am tomorrow:
Base: 0-5 E
Ridge Top: 0-10 E shifting W
Trend and Timing:
East flow will remain intact at pass level, while
ridge top winds shift westerly.
|
JM
No comments:
Post a Comment