Gorge Ice Storm Update: More Damaging Ice Through Tonight

January 20, 2012

One more weather development this morning, that approaching low pressure center is pulling quite a bit of cold air through the Gorge, more than I expected. In fact it’s deepening east of the Cascade Crest.  Auspurger Mountain (~3000′), was 38 degrees at 4am but is now down to 21!  The cold air is banking up against the east side of the Cascades.  Same thing with a dropping temperature across the river at Greenpoint SNOTEL site at about the same elevation.  So the cold airmass over there is around 3,000′ thick.  With such thick cold air, temps are now at/below freezing at the west end of the Gorge above about 1,000′ with a strong east wind.  Vista House wind sensor froze up around 10am…you can see it here.  And at my home I have ice starting to form on trees, but not on the road/pavement.  Seems like it needs to be about 30 degrees with freezing rain to get ice on pavement during the day.  It’s interesting in situations like this where the temp goes from 34 to 33 to 32 etc…; it’s just raining like normal, and then all of a sudden you notice ice is forming on objects while it continues to rain at exactly the same rate.

If you’ve lived in the Columbia River Gorge long, you know that to get the cold air out, the wind needs to switch to west.   There is good and bad news on that front:

Bad:  There will be no wind switch and thus no warmup until the very early morning hoursThe Ice Storm will continue until that time.  Anything that falls will fall as freezing rain or possibly sleet (ice pellets);  more thick ice building up on all objects.   That could easily add another 1/2″ ice accumulation.  There are already trees and powerlines down all over the place out there in the Hood River Valley and east to The Dalles, Lyle etc…; it’ll get worse before it gets better.

Good:  Sometime between 4am and daybreak a good surge of 45 degree westerly wind will punch through the east end of the Gorge, aided by a much cooler airmass moving in above too (sounds strange, but this helps mix out the cooler air at the lowest elevations).  That breaks the inversion currently in place with below freezing air below but mild temps in the mountains.  So tomorrow will be MUCH warmer for storm cleanup.

By the way, if you have good ice storm pictures, send them to photos@kptv.com and we may be able to get them on-air to show others.

Chief Meteorologist Mark Nelsen

11am: Quick Update

January 20, 2012

Pretty quiet this morning with light rain picking up across the area.  Here in the Portland Metro area we have a mainly uneventful weather weekend on the way (including today):

FLOODING:  All rivers continuing to recede today since we had almost 24 hours with no rain in the central Willamette Valley.   The rain the next 3 days will be light enough that none are forecast will return to flooding. 

 ICE STORM:  The Columbia River Gorge has an Ice Storm Warning.  All of today’s rain will fall as glaze ice east of Cascade Locks.    What a mess developing in the Hood River Valley and in The Dalles too.  I see slightly colder air moved in overnight in that area.  Middle Mtn (in the MIDDLE of the Hood River Valley…hmmm…) went from low 30s last night down into the mid 20s now.  So it’s a good 2,000′ layer of chilly air stuck.  That won’t get dislodged until the wave (related to wind westside) comes through late tonight.  Could see another 1/2″ ice easily.

WIND:  Model are noticeably weaker this morning with the wave coming through tonight.  Still windy along the Coast, gusts up around 70 mph for a brief period 11pm-3am there.  But nothing too unusual.  Here in the Valley, only the MM5-NAM is holding onto a strong southerly gradient (18mb OLM-EUG).  The WRF-GFS and our RPM have 13-16mb gradient OLM-EUG.  That would be more of a “wind advisory” event with gusts around 40 mph.  Once again, nothing unusual there.  So as of now, I don’t see a windstorm overnight.  Hopefully the 00z model runs are weak as well.

And now…I…am… “checking out” of any weather activities until I get to work around 2pm…not even going to think WEATHER for the first time in a week…

Chief Meteorologist Mark Nelsen