June 12, 2024

More Rain for the Northwest is Good News for Wildfires

After a very pleasant dry spell, another rainy period is ahead for the western side of the region and the Cascades on Friday and Saturday.   And there is no hint of heat waves in our future.

Today and Thursday will be partly sunny, with highs in the upper 60s to low 70s in the west, with the Columbia Basin being about 10F warmer.   Typical June weather.

But on Friday, an upper-level low-pressure area (or trough) will be moving in (see below for 8 PM Friday), bringing clouds, showers, and cooler temperatures.

Such features have been persistent this spring.

The forecast 24-h precipitation total ending 5 PM Friday shows showers in the west, with the heaviest precipitation along the coast.  Eastside dry.

The next 24-h (ending 5 PM Saturday) is quite wet in the West, particularly over the western slopes and crest of the Cascades.  

Perhaps not the best day for a Cascade hike.


As the system passes through, the region will dry out on Father's Day (Sunday), except for a band of Puget Sound from the Puget Sound convergence zone and over northeast Washington.


The predicted temperatures for Seattle (below), show a substantial cool-down over the weekend (about 10F below normal on Saturday), but warming to near-normal conditions (low 70s) next week.   Again, add about 10F for the Columbia Basin.


All the gnashing of teeth and predictions about summer drought and wildfire by certain media outlets does not appear to be well-founded.  

Below is the latest one-week predicted significant fire potential by the Northwest Interagency Coordination Center, which is responsible for region wildfire prediction.  Green indicates below-normal potential.   Looks favorable.


The most skillful extended forecast is by the European Center and their latest guidance predicts COOLER than normal conditions for the next month over most of the region (see below)


Of course, we have the challenge of July 4th, where crazy people shooting fireworks start many fires. often in dry grass.  Hopefully, the grass will be moist this year.


June 09, 2024

Lightning Returns to the Pacific Northwest

 Lots of thunderstorms, some approaching severe levels, have hit eastern Oregon and Washington during the past day.....and there are severe thunderstorm warnings out between Wenatchee and Spokane as I write this blog (see below).


The latest radar image over eastern Washington shows strong storm cells, with the red colors indicating substantial radar reflectivity.   Such high levels are either very heavy rain or hail. 


Earlier today (around 3:30 PM) similarly strong storms were moving eastward across southeast Oregon (see below)


Precipitation during the past day has been substantial over southeastern Oregon (up to 1.23 inches) and northeast Washington has also experienced some of the thunderstorm showers (see below).


This is the first major lighting event of the year for our region.    Yesterday (Saturday), there was a substantial number of lightning strikes over eastern Oregon ( see below).


The latest lightning strike map (at 7:50 PM Sunday) shows plenty of lightning, with thunderstorm cells over eastern Washington and others over southeast Oregon.


And here is the total lightning strike picture for Sunday.  Southeast Oregon and downstream are well covered by lightning, with quite a few over NE Washington.



So why so much lightning?

Today an upper-level trough moved through, as shown by the weather map at roughly 18,000 ft (500 hPa) this morning at 8 AM (the red dashed line shows the trough line).   In front (east) of the trough, there is both upward motion and the movement of warm, moist air from the south, both very favorable for generating thunderstorms.   


The atmosphere over eastern Washington and Oregon had lots of CAPE (Convective Available Potential Energy)... think of this as fuel for thunderstorms.  

To illustrate,  here is the CAPE prediction for 8 PM tonight (Sunday).  Some values getting as high at 600 (J/kg).  Decent for around here, a big yawn for those in the Midwest.


All our local thunderstorm action will be over over night as the trough moves inland and cooler marine air moves into the region.



More Rain for the Northwest is Good News for Wildfires

After a very pleasant dry spell, another rainy period is ahead for the western side of the region and the Cascades on Friday and Saturday.  ...