Record setting “heat” still on track Friday, including 80+ at the ocean beaches

9:30pm…

Just a quick blog post this Thursday evening to let you know the forecast is still on track. I’ll try to keep it brief; although that’s always a problem for me.

SUMMARY

• Today was warm, 81 in Portland. We’ll add 6-10 degrees tomorrow. That puts us somewhere between 87 and 91 degrees for an afternoon high in the metro area. Yep, it’ll definitely be on the edge of “hot” from 3pm-6pm. An easterly breeze will temper that warmth a bit. Regardless, Portland will blow past it’s record high for the date of 82 degrees. There is a chance we reach the all-time April high temperature of 90 degrees tomorrow.
• There’s no need to worry about heat stroke or heat exhaustion, unless you are stuck inside a car with the windows up. It’s not like we have a 95-100 degree day on tap. Plus we start in the 40s and lower 50s. No one’s home will be “hot” tomorrow afternoon.
• Easterly wind pushes the very warm weather all the way onto the northern part of the Oregon coastline and Washington too. Tomorrow will be the one day in the 80s from about Pacific City northward.
• We drop about 10 degrees Saturday, which makes that day feel about like today. Ocean beaches drop back into the 50s!
• A major marine push of chilly ocean air surges inland Sunday; a very different day with highs in the 50s or lower 60s and cloudy skies most of the day. Quite refreshing!
• The only rain this weekend will be a few sprinkles or drizzly areas on Sunday. Much of the day will be dry in the lowlands

First, the numbers recently. One week ago most of us were looking for anything above 60 degrees. How things have changed these past two days!

(kptv)

Notice our “first 80″ seems about on schedule. Also notice the last 10 years we’ve been seeing that first 80 degree day a bit earlier than average

(kptv)

Of course the big upper level ridge is overhead right now, just as forecast over the past week. I’ve mentioned this in the past, but these warm weather/heat wave events are very well forecast by models.

(kptv)

By Sunday the ridge has weakened a bit and a cold upper-level trough is approaching. At this point a cold front is passing by at the surface too (midday Sunday)

(kptv)

Then that trough “cuts off” well to our south later Monday through Wednesday. This takes most of the showers south of us early-mid week. So we aren’t heading directly back into a cold/showery pattern. This setup on Tuesday can give us some warm and partly cloudy weather. If that low gets any closer we can get showers or thundershowers coming in from the east or southeast

(kptv)

We are all set tomorrow for record setting warm weather. The Salem sounding was +14.6 degrees at 850mb (5,000′) this afternoon. Tomorrow afternoon models are forecasting a near record high (for April) around +18 to +19. Here’s the GEM model for tomorrow at 5pm

(kptv)

The record for April is +20 in the Salem sounding record back to 1950. So we’re headed into the upper 80s or even 90. So could we break the April record high of 90 degrees in Portland? Possibly. We will see. The wind situation is critical for the coastline tomorrow. Anyone that keeps easterly wind through early afternoon will see temps jump into the 80s. Our GRAF model looks like this at 5pm. Wind arrows are surface wind (red = offshore, blue = onshore)

(kptv)

Then by Saturday afternoon a westerly wind is keeping the coastline in the 50s, and chilly marine air is pouring through the Coast Range gaps. We should be 6-10 degrees cooler in the valleys Saturday; similar to today.

(kptv)

The BIG change happens Saturday night. A major surge of marine air + cooling atmosphere overhead means we head back into spring. The cloud cover will stretch all the way up to 6,000′! That thick of a marine layer won’t go anywhere, and a mammoth west wind is blowing out at Hood River, The Dalles, and Biggs. Expect gusts 40-55 mph out there; great mileage if you are driving I-84 to Pendleton Sunday. Portland will be 30 degrees cooler Sunday than Friday. Although other than spots of drizzle, it’s not very wet.

(kptv)

So there’s something for everyone the next 3 days…

Warm and dry spell begins Tuesday, plus what we’re seeing for early May

7pm Monday…

I think just about all of us are ready for the well-advertised warmup this week. Some were doubtful after 2 aborted warming forecasts, but this time models have been in great agreement that we’ll finally see much warmer than normal temps for the first time this spring.

KEY POINTS

• We have at least 5 consecutive dry days on tap (Tuesday through Saturday). The next CHANCE for showers is Sunday
• Afternoon high temperatures climb above normal Tuesday, then soar to 15-25 degrees above normal Wednesday through Saturday
• No HOT weather is expected. Even when we hit 85+ this time of year, much of the day is spent in the 60s and 70s…it ain’t summer!
• The cooldown will be dramatic, and likely on Sunday. Temperatures drop 20-30 degrees from Friday’s high in the 80s.
• I don’t see a return to excessively wet/cool weather NEXT week. The first week of May will just feature normal temps/rain, not the really cold stuff

ALL THE DETAILS

I just checked the numbers for spring so far…generally it’s the coldest in 15 years west of the Cascades.

(kptv)

It’s the 4th wettest April on record in Portland. We sure won’t make it to #1 since the only rain left will be some really light stuff on Sunday the 30th

(kptv)

So we’ve got a big change ahead. For the first time this season a strong upper-level ridge of high pressure has begun developing in the Eastern Pacific. That ridge (where the jet stream moves well north of us) sits right over us through Saturday. Here’s the view Wednesday at 18,000′

(kptv)

Now by Friday midday the ridge is directly overhead.

(kptv)

When that happens we get a low-level easterly flow over the Cascades and through the Gorge. Regular viewers/readers know that anytime we get east wind from April to early October…it’s a “warm” wind. I mean much warmer than normal. Heating is maximized in this setup, thus Friday is the warmest day in this warm stretch. If you look closely at the chart, you see a little wiggle in the flow to our west. That’s an upper-level disturbance that passes by Friday night and Saturday, flattening the ridge a bit. This is a signal that we lose the east wind Saturday, but at this point I don’t see a strong onshore flow. So I think “summer” will continue for one last day Saturday. Then a major marine push of cool air surges inland Saturday night along with a cold front. That combination will likely drop us 15-25 degrees in one day…Saturday is the warm day this weekend. By Monday, an upper-level trough has replaced the warm ridge, although it appears weak/splitty.

(kptv)

I’ve shown the ECMWF model here, but ALL models agree on the same setup the next 7 days. Note that cloud cover is minimal or non-existent from midday tomorrow through Saturday in the western valleys of NW Oregon and SW Washington.

he big question in this setup? How warm do we get in the lowlands? For that we use 850 millibar temps. That’s the temperature up around 4,000′ or so in Celsius. The highest on record (from Salem historical soundings) for the month of April is +20. That was set in 2016; read about it in this blog post from 7 years ago. Several major model (ECMWF, GEM, GFS) ensemble averages are showing: +10 to +12 Wednesday, +13 to +16 Thursday, +17 to +19 Friday, and +12 Saturday. That +18 average for Friday is right up near that historic high for April! That puts high temperatures that day between 85-90 degrees with the easterly wind and full sunshine. That’s why we’re forecasting a record high for Friday and my gut feeling is that we’re going to see spots hit 90 for one day.

(kptv)

How warm CAN it get in April? Since 1940, we’ve hit 90 once. That was the last day of April 1998. Clearly Friday will be one of the top 5 warmest days we’ve seen in April.

(kptv)

So the forecast is pretty clear cut now; enjoy the warm sunshine. My grass (up at 1,000′) has barely started growing and I haven’t even attempted to plant even the cold weather veggies. This will be a nice kick-start to warm the ground. How about that first week of May? Models are hinting that trough offshore model “pinches off” and it heads for California much of NEXT week. The 7 day rain forecast for May 1st to May 8th isn’t especially wet over the Pacific Northwest. This is the ensemble average from last night’s Euro run. It’s wet at times in California, which doesn’t leave us dry. But it’s also not a soaking wet pattern for us.

So I think the weather next week will feature pretty typical early May stuff. You can add about 5 degrees to most days of this ECMWF ensemble forecast for the next two weeks. Lots of highs in the 60s will follow this abnormally warm event. Much better than the upper 40s and 50s that have dominated most of April.

Enjoy the dry days ahead!

Finally! Confidence growing that a warm and dry stretch on tap during last week of April

9pm Thursday…

What a soaker this Thursday evening. A warm front has dropped plenty of rain this afternoon/evening. Portland is up to 4.65″ rain for the month as of 8pm this evening. That just about puts us into the “Top 5″ wettest Aprils.

(kptv)

Maybe more interesting is that last year’s wettest “ever” April followed the driest April on record in 2021

(kptv)

Tonight’s system will shift east and we’ll see very little rain tomorrow and Saturday. Most likely less than .10″ west of the Cascades. Of course it was very cold (for late April) today too…our 2nd coldest day of the month and we couldn’t even make it to 50 degrees! Our typical high is 63 this time of year

(kptv)

SUMMARY

1. This spring has been the coldest/wettest since 2017, or 2010, or 2008. The ranking depends on how you measure it.
2. This spring has not been “unusual”; it’s just that we’re getting a cold/wet spring. Every few years it happens. One could argue it’s very likely that NEXT spring will be warmer/drier than this year. Or at least warmer, or drier (maybe not both).
3. The cold/wet spring has delayed the spring melt in the mountains
4. This has likely been the toughest start to the gardening season we’ve seen since 2010/2011. Cold soil and lots of rain!

WHAT’S AHEAD

During these cool/wet springs, all of us are looking for that first warm/dry spell. You know what I mean; several days of sunshine plus a dry easterly wind, pushing temperatures up around 65-75 degrees. Glorious… In MOST years, we see that in late March or early/mid April. But in these cool/wet springs, sometimes it doesn’t happen until late April or even May!

The good news is that we finally see a significant change on the horizon and it’s just a few days away. Of course we’ve been extra wet and cool because the north Pacific jet stream has remained a bit farther south than normal. But ALL models agree the jet will shift north next week, leaving us dry beginning Tuesday and that likely continues for at least the following 5-6 days. Look at the flow up around 18,000′ for tomorrow (500 millibars). Flat flow, but we’re on the warm side of the jet stream. The result is warmer weather both tomorrow and Saturday. In fact that day should be the warmest so far this month.

(kptv)

One last cold trough swings through Sunday night and Monday morning

(kptv)

Then by mid/late next week a strong ridge forms along the West Coast. Here’s Thursday

(kptv)

That’s a pattern that gets us into the 70s or even 80s in late April. All model ensemble averages are around +10 deg (C) at 850mb next Tuesday through Thursday. Those averages, along with sunshine and weak offshore low level flow, pushes us into the 73-78 degree range. Possibly even 80. Operational model runs are as warm as +14 to +16 which would push us into the low to mid 80s! Regardless, it’s going to be quite a chance compared to upper 40s today…

Is it possible that this will be the 3rd time this month we end up far cooler than models initially showed? Yes, but this time is different because models aren’t backing off as we get closer. And there is great ensemble agreement unlike earlier in the month. Notice the Euro ensemble 24 hour rain chart for the next two weeks. The vast majority of ensemble members (horizontal lines) go dry after Monday for at least 4-7 days.

(kptv)

IF we get to 80 next week, that won’t be unusual for April. About 1/2 of recent Aprils have featured an 80 degree temperature.

(kptv)

That’s it for tonight, enjoy the (slightly) drier weather tomorrow and Saturday.

No, you aren’t crazy! First half of spring has been unusually cold & wet

9pm Friday…

This is my 32nd spring forecasting weather west of the Cascades. That means I’ve seen a bit of everything over these decades; so nothing seems too shocking/surprising when it comes to spring rain and cold. That said, maybe I’m just turning into the old guy that waves off anything dramatic with a “I’ve seen this before…it’s no big deal!”. So let’s check out the numbers and see how unusual this spring is so far.

First, meteorological spring is March 1st through May 31st. So we’ve almost reached the halfway point. March was very chilly across the entire western USA; most of Oregon was in the WELL BELOW NORMAL category.

(kptv)

That trend has continued this month with no days reaching a normal high (60-62 degrees) in Portland! These first 13 days are the coldest since 2011.

(kptv)

In fact for most western valley locations it’s the coldest early April since at least 2011. I sure notice at home (1,000′ in western Gorge) that no trees have turned green yet and my apple/pear trees aren’t even close to blooming yet. I suppose that’s good in case we get a frost again in the next week.

(kptv)

This means you can put a big checkmark beside SPRING 2023 = MUCH COLDER THAN NORMAL.

Rain? Yep…very wet in April so far. I had blocked out the fact that April 2022 was the wettest on record in Portland! But this year we are even wetter in the first 13 days than last year at this point

(kptv)

If you are a gardener like me, you know it’s been difficult to even get things started with this cold/wet combo. Unfortunately I don’t see any sign of a change for at least another 7-10 days. Of course the reason we’ve seen this pattern is because the jet stream keeps dipping down into the Pacific Northwest. Cold upper-level “troughs” in the jet drop in over our region. We are getting just a brief break today through Saturday as an upper-level ridge builds just to our east. That keeps wet Pacific weather systems away.

(kptv)

But then it’s back to cool/wet early next week. Check out the view Monday

(kptv)

Then next Wednesday, the 19th. Another cold pool of air is sitting overhead. It won’t be quite as chilly as yesterday’s that brought sticking snow close to sea level in spots. Those of you up around 1,500′ can expect at least a dusting of snow once again around Tuesday/Wednesday mornings.

(kptv)

Looking farther ahead, this general pattern with cool troughs dropping into the western USA doesn’t seem to change for at least another 10 days. That’s through at least the 23rd or 24th. The main message here is that we are stuck with this pattern through at least next week

SUMMARY

• This has been the coolest/wettest 1st half of spring we’ve seen in at least 10-12 years
• After these three mainly dry days, rain returns Sunday
• Early-mid next week features chilly temperatures and cold showers once again
• The cool/wet pattern likely continues through at least Sunday the 24th