Long Range Maps

February 6, 2012

I’m not working today, but, well, I still look at weather maps…it’s in my genes apparently.

The LONG range pattern that’s mostly agreed upon by the GFS, GEM, and ECMWF is that the current ridge over western North America will shift to just west of the West Coast in the 8-16 day period, then possibly shift slightly farther west according to the ECMWF:

Here are the weekly ECMWF 500mb height anomalies for the next 4 weeks from last night’s run.  The first map is for days 1-7, and the last is for the first week of March.  You see the retrogression clearly:

This is a drier than normal pattern the first week or two, then probably wetter the last week of February and early March. Keep in mind we’re talking the next 30 days, but I’ve noticed the ECMWF has been showing this general progression of the pattern for the past week.

And here is the 00z 360 hour (16 days out) GFS ensemble version of the same thing:

The GFS is not run past 16 days, but notice it’s quite similar with the ridge (2+ weeks from now) centered to our west, maybe slightly closer to us than the ECMWF shows.

Based on these maps it’s reasonable to say:

-Drier than average weather will continue the next 7-10 days, but not totally dry.
-No flooding, freezing rain, or low elevation snow
-Some mountain snow will return
-Temperatures may go to cooler than average (for more than a day or two) the 2nd half of February.
-Lower elevation snow and/or much wetter weather systems COULD show up near the end of the month.

Chief Meteorologist Mark Nelsen


New Weather Podcast Posted!

February 6, 2012

Our latest episode of the Northwest Weather Podcast is up!

Check it out by clicking here!

Brian, Mark and Steph welcome back one of our favorite guests, Meteorologist Rebecca Stevenson, to talk about the recent winter storms.

Plus, they’ll talk about some extreme rules governments are putting on meteorologists in other countries, the latest on the controversial climate change meeting in Portland and more about Stephanie’s car than you’ve ever wanted to know.


Big East Wind Today

February 6, 2012

The easterly Gorge wind was a bit mellower over the weekend, but it’s roaring back this morning. 

Peak gusts are in the 40-50 mph range in Troutdale/North Gresham areas and now they have suddenly picked up the past two hours at Vista House, gusting over 70 mph (which should mean about 80-95 on “the steps”).    The easterly pressure gradient was around 6.5 mb last night at sunset, but now it’s risen to over 10 millibars.  Combine that with a mild atmosphere overhead (inversion) and today/tonight might be the strongest we’ve seen in awhile.  I noticed last night’s 4km WRF-GFS cross-section forecast had a few 50 kt. barbs on it for later today; it doesn’t get any higher than that:

And our RPM has shown a pick up in the windspeed for Monday-Tuesday AM for a couple days now:

Add in an approaching surface low and it’ll be interesting to see how high the wind goes.  During strong east wind spells, the Corbett sensor usually gets well into the 60s or even touches 70, but so far this morning it has stayed below 60.  That’ll change.

The good news?  We’re approaching the end of the east wind season…November-February is the peak, so just a few weeks left to go!  Sure it can still get windy in early March, but inversions disappear at the end of February east of the Cascades so high pressure doesn’t hold on for days and days and days…

I’m not working today and will just be puttering around outside in the sun, so if it gets really wild I might head down to Vista House later in the afternoon.

Chief Meteorologist Mark Nelsen