11:30pm UPDATE

May 15, 2006

Last shower/thundershower seems to be heading up the Clark County foothills of the Cascades at this hour.  Shortwave passing overhead tried hard to produce some cells, but now that is passing on as well.  So it’s on to onshore flow the next few days keeping highs a bit more reasonable.  Probably not out of the lower 80’s.

Long range models are all over the place from Friday through early next week.  Amount of showers and cooling is dependent on where the trough offshore goes.  My gut feeling is it’ll move close to us (remember, it IS May!) and cool us into the 60’s…Mark Nelsen


6:30pm UPDATE

May 15, 2006

12z & 18z models definitely backed off on convection for this evening.  And I see no reason to disagree looking at the radars.  A few clumps of cells in the Central Cascades and into Deschutes County, but that’s it.  Plus the cells appear to be moving straight north, so lightning in the metro area may be a long shot for tonight.  Closest lightning to the metro area has been around Santiam Pass. 

We should get a burst of southwest wind though around 8-10pm as a shallow, but fast moving layer of marine air slides in…Mark


Monday Morning Update

May 15, 2006

An interesting weather day on tap for today, plus I’m up early for KXL radio today, so what better time for an early blog?

It’s amazing how little has changed in 3 days.  Thermal trough is at the coastline this morning, pulling easterly wind into it.  Gorge gradient is 5 millibars this morning…very strong for the warm season.  I don’t think I’ve ever seen it go above 6 mbs. between April & October.  But my favorite weather tidbit of the day is from Tillamook.  49 degrees with a calm wind at the RAWS station there at 6:10am.  At 7:10 it was 70 with an east wind gusting to 15.  Thats 21 degrees in one hour!  A very warm atmosphere over us too with Timberline near 60 degrees at daybreak.

So we’re all set for a hot day, the only thing to mess with the high is the cloud cover.  Abundant high level clouds streaming north out of California this morning; it’s quite a moisture plume.  If we don’t get at least partly cloudy skies, 90 will be tough to hit.

All the parameters (high cape, low lifted index, shortwave overhead and thermal trough below) are there for a few thunderstorms this evening.  I do think there WILL be scattered thunderstorms this evening or overnight, but of course I can’t tell you where.  East side of the valley near Cascades is almost always a better bet (Estacada, Oregon City, Gresham, Troutdale, Camas etc…), but it’s possible to see one almost anywhere.

That will be the last of the east wind this week, so since it’s May, we will stay below 90 the rest of the week.  In July/August you don’t need an east wind to get to 90….Stay cool today, Mark