After a very cool two weeks, the Pacific Northwest has “turned the corner” and now we’re seeing more typical April weather. In fact temperatures will be near or above normal for at least the next week. Plus, we’re headed for our first 70 degree day of 2020 tomorrow! This is the typical time of year we see our first 70 degrees.
Over the past 30 days most of the western USA has been experiencing below average temperatures. Only the yellow/orange colors on this map represent warmer than average weather:
Precipitation has been below normal as well…in this case the colors yellow/orange on the map below represent drier than typical conditions over the past month:
High pressure is building offshore and upper-level maps show that ridge cozying up to the West Coast the next two days. Right now:
But then the ridge weakens a bit and shifts a little farther west again. This is Easter Sunday. Much of the nation east of the Rockies will see some cold Easter Egg hunts.
For us? The strong ridging just west of us the next week means little or no rain. That’s the easiest part of the forecast. Then it’s a matter of how warm we get the next two days and how much cloud cover Friday/Saturday as a weak disturbance moves by.
First the warm weather. Today we’ve seen relatively strong “onshore flow”, that’s air flowing from ocean inland. But models show 2-3 millibars of easterly flow through the Gorge and over the Cascades by midday tomorrow. Easterly wind from late March to mid-October is a “warm” wind. That’s warm relative to normal. Not like that cold east wind from Halloween to St. Patrick’s Day. The WRF-GFS model from UW shows this at 2pm:
Tomorrow we add in 850 millibar temperatures (temp at 4,000′ or so) of +10-12 deg. celsius; quite a bit warmer than the +4 we saw today. Then add all-day sunshine both tomorrow and Thursday. Taking a look at my warm season “magic chart” for April, historically we have seen high temps at PDX between 72-80 degrees with this same setup. In 2009, we hit 78 at PDX on April 6th with similar conditions. Those 80 degree highs on my chart were likely later in the month. So, our forecast of 72 tomorrow and 74 Thursday seems good. It’s quite possible we hit 70 tomorrow and 76 Thursday instead. Or 73/73.
You get the idea…it’s going to feel like May for the next two days!
Onshore flow returns Friday with morning clouds, then more of that cool onshore flow might even give us a sprinkle or drizzle Saturday. This is our only chance for rain in the next 6 days.
As cold air surges south out of Canada Saturday night and Sunday, we get another round of offshore flow. Although the airmass will be cooler, this means Easter Sunday may just be sunny with temperatures in the lower 60s for your egg hunts.
THE LATEST ON WORK CONDITIONS HERE AT FOX-12
We are still doing some serious “social distancing” here at KPTV/KPDX like many of you. In the past 10 days two of our meteorologists have “left” the office. Both Brian MacMillan and Jeff Forgeron are broadcasting from home. That’s not because they/we have any virus issues, but to move us farther apart. Fewer people in one space = good.
It’s amazing; with today’s technology we are able to perform just about all tasks from home that we can do at work. 20 years ago this wouldn’t have been possible.
The rest of us are still working here. I have to admit I don’t mind working alone in this environment at all. I go most of the work day without getting physically close to coworkers as mentioned in a previous post.
Stay healthy this week and enjoy the sunshine!
Chief Meteorologist Mark Nelsen