Snow Totals II

February 27, 2007

Okay, this may be the last of the season…you know the rules.

Snow accumulated on the ground only in this post…no weather discussion here, do that below.

1.  Depth
2.  Location
3.  Elevation if you know it

Another Tough Forecast

February 27, 2007

Snapshot_28Once again, a break this evening as we wait for another surge of moisture to move onshore.  Today’s heavy showers were concentrated on the west side of the metro area.  I notice Council Crest at 1000′ had 2.5", but Welches at 1400′ had nothing.  If you want snow, it doesn’t help if you have cold enough air but not enough moisture.  The airmass overhead cools in the next 24 hours, but I’m a bit concerned that we may not get enough moisture for metro area snow tomorrow.  To get snow in Portland, we need to see good steady precipitation before 10-11am.  Since it’s the last day of February, temperatures rise each afternoon with the increasing insolation (warmth from the sun).  MM5 and our model here both have a nice band of snow moving over us right at daybreak.  This is what I’m pinning hopes on for tomorrow.  I think this could be our last flirtation with snow for the season.  It looks like showers taper off tomorrow evening with drier conditions Thursday morning.  The steady precipitation that arrives Thursday afternoon does so with an increasing southerly wind, so the snow level will quickly lift up to around 2000′.
Longer range maps have some ridging and drying over us this weekend.  The best chance for dry weather will be Sunday.  It is early March so 60 degree temperatures shouldn’t be hard to hit…Mark

The Morning Letdown

February 27, 2007

Models were partly right, but more important, partly wrong.  Surface low is sitting right near Tillamook/Seaside at 9am.  That’s farther north than expected, so milder southerly wind has arrive in the interior as far north as Clark County.  That boosted temperatures up after midnight.  I expected the low to track closer to Newport, keeping the south wind out of the metro area and northern Willamette Valley.  Looks like sticking snow is mainly above 500′ at this hour and probably won’t go any lower with slight daytime heating.  Precipitation forecast was about right with heavier precip holding off until 8am or so.  Atmosphere overhead is quite cold with the freezing level not much above 1000′, so a cold snow/rain day in the metro area.  Freeways and main roads below 500′ should remain clear but several inches of snow closer to 1000′ and up are likely…Mark