PNW April 2023 Weather Discussion

[TT-SEA]

Just now, Slushy Inch said:

60s in WA 80 in Portland.

ECMWF cold bias near the Puget Sound will be in full force with this pattern.   If the 500mb pattern verifies then it will be warmer up here.  

[Slushy Inch]

1 minute ago, Cascadia_Wx said:

One big story is how wet Thursday/Friday have trended on the Euro. Meanwhile the warmest stuff keeps getting pushed back to the very last day of the run.

Not surprised. Seems like any major pattern change tends to be pushed back.

[Slushy Inch]

1 minute ago, TT-SEA said:

ECMWF cold bias near the Puget Sound will be in full force with this pattern.   If the 500mb pattern verifies then it will be warmer up here.  

Oh it does? Good to know. Didn’t think it made sense to just see 60s.

[Anti Marine Layer]

1 hour ago, Thunder98 said:

Its currently 120F in LA right now! 

April fools

[TT-SEA]

GFS shows basically no rain Thursday and Friday... GEM shows very little.   But this is the second consecutive ECMWF run to show significant rain those days.   Probably best to assume the ECMWF will be right and personally that would be my preference.   But sometimes the GFS ends up being sneaky good with pattern changes.

[TT-SEA]

3 minutes ago, Slushy Inch said:

Oh it does? Good to know. Didn’t think it made sense to just see 60s.

Definitely a cold bias... most pronounced on sunny days from April-October.    We have already seen it show up on numerous sunny days in March as well. 

I think it was @bainbridgekid who joked last summer that the ECMWF seems to think the waters of the Puget Sound are in the 30s all summer.   

[Cascadia_Wx]

Moderate ice pelletey shower here and down to 42. Have only had a high of 45 so far today.

[Cascadia_Wx]

You can see that some GEFS ensemble members show the wet period Thursday Friday. Also liking the quicker breakdown of the ridge and decent agreement on the long range between the operational, control and mean. I say bring on a warm spike.

[Slushy Inch]

Puget sound action around 3pm? Let’s see how it does.

[TT-SEA]

12Z EPS definitely shows that trough on Thursday and Friday.

[T-Town]

43 at 12:30 pm. Chilly. Just catching the northern tip of a passing shower. 

[Ken in Wood Village]

A couple of lightning strikes 🌩

[Ken in Wood Village]

5 minutes ago, Ken in Wood Village said:

A couple of lightning strikes 🌩

Things are getting active 🌩

[Doinko]

3 minutes ago, Ken in Wood Village said:

Things are getting active 🌩

I would probably be able to see some lightning from home but I'm in Hillsboro right now. Hopefully some more storms can form!

[Slushy Inch]

4 minutes ago, Ken in Wood Village said:

Things are getting active 🌩

Y’all down south get way more lightning.

[T-Town]

Awesome clouds today. 

[Ken in Wood Village]

Hail 🌩 I was at the gym...lol

[NWbyNW]

Has been hailing here in Everett for about ten minutes. Big hail. 

[Slushy Inch]

4 minutes ago, NWbyNW said:

Has been hailing here in Everett for about ten minutes. Big hail. 

Not graupel?

[Slushy Inch]

5 minutes ago, NWbyNW said:

Has been hailing here in Everett for about ten minutes. Big hail. 

Looks like it may swing south.

[Slushy Inch]

Lightning! Fun spring PSCZ.

[Slushy Inch]

Also some rotation.

[Slushy Inch]

Would not be shocked to hear that a funnel or waterspout was spotted over the puget sound.

[Meatyorologist]

I'm currently running a 47/36 spread here at my house. When glancing at the 12z 3km NAM lapse rates depicted for right now, that translates to roughly 4-700j/kg of unrealized CAPE, which is on the upper end of average for these Springtime cold core convective setups. The only thing preventing any convection over the Seattle area is the northward displacement of the convergence zone. As of right now the metro area down to about Federal Way is under midlevel subsidence related to that, preventing deeper convection.

Some lift ahead of a main batch of PSCZ-related showers currently parked over the Olympic peninsula is currently spawning a low level cumulus field over Seattle with some very shallow pseudo-convective drizzle over Snohomish county; a pretty good indicator that the near surface environment is quite ripe and moist ahead of any impulses we see today. One thing to watch for is to see if this drizzle expands in coverage and disarms the environment via evaporative cooling.

CAM's are quite trigger happy with a branch of potent showers popping up over the central Sound and swinging through the north side of the city over the coming hours. The fast cell motion and strong westerly flow should allow the environment to overcome that PSCZ-related subsidence.

[Meatyorologist]

Those are some boomers! They're perched across the Sound but those towers reach way above the horizon, and even the apartments around my house.

Clearing now, which is a good sign. Should prime the environment more

[Doinko]

Just now, Meatyorologist said:

Those are some boomers! They're perched across the Sound but those towers reach way above the horizon, and even the apartments around my house.

Clearing now, which is a good sign. Should prime the environment more

Pretty sunny now with some more showers to the west. Hoping to finally see more than some distant lightning, it's been a few years

[Meatyorologist]

Divided sky.

[SilverFallsAndrew]

Sunbreaks gonna get this thing cranking!

[Meatyorologist]

Just heard some thunder. This thing is powerful. It looks and feels the part, with how divided the sky is and the structure of the cumulonimbus towers. On radar the whole thing is bowing out, with a nice pool of cold air reinforcing on the back side. Looks like this PSCZ is taking advantage of the speed shear left in the wake of the Olympics.

Currently enjoying the sunny subsidence region to the south of the 'zone. Getting windy as we're pushing past 50F and mix some of those strong SSW'lies to the ground.

[NWbyNW]

Has been hailing for about a half an hour. Everything is white.  Has not let up. 

[T-Town]

[Meatyorologist]

I know I keep updating ever two seconds but this is evolving quickly. The good events tend to do that. Absolutely gnarly sky. Been hearing more thunder.

[NWbyNW]

Hail continues to fall.  Here are two video clips.  Temperature is 40F in Everett.  Feels much colder.  At noon the temp was 45F.

 

 

[Ken in Wood Village]

37 minutes ago, Doinko said:

I would probably be able to see some lightning from home but I'm in Hillsboro right now. Hopefully some more storms can form!

It's still early in the day. I think it's just starting. Also, we still have a chance of thunderstorms tomorrow too

[NWbyNW]

Still hailing.  Coming down hard.  This might be the longest I have ever seen hail fall and at this size.  Over a half and hour now officially. 

[Cold Snap]

Currently 47/37 for the day. Decently chilly afternoon for the 1st of April especially with there being sun breaks.

[Ken in Wood Village]

I thought I would post another radar loop. As you can see, things are getting going. I think the thunderstorms will develop fast and could be right on top of you and not know it until it hits you. 

[T-Town]

Love the hail videos. Hoping one of these showers can hit me. 

[Cold Snap]

I can see the dark clouds from the CZ to my north and west and it has started to get very windy here in the past 30 minutes.

[Cloud]

To me, it’s a bit difficult to differentiate whether the stuff up north is graupel or hail. The texture looks like it should be graupel but perhaps some hail mixed in as well. 

[Ken in Wood Village]

There is a lot of cold air out in the Pacific. All that popcorn looking clouds. With having a lot of sun breaks, that gives us a lot of instability to make those showers into thunderstorms. 

[kokaneekidz]

Hailing here. A skiff of accumulation 

[NWbyNW]

Still hailing here in Everett.  There was a short break for a few mins then it picked up again.

 

 

[Ken in Wood Village]

More lightning. These storms are moving fast. It shows them moving at 27 kts.

[T-Town]

Shower came through and dropped the temp from 47 to 41. 

[MossMan]

Most of the action has been a few miles south of me since this morning. Met up with my dog training friends east of Mt. Vernon earlier, had a few moments of hail but otherwise dry. Cold though, currently 39 at home. 

[Meatyorologist]

Nice looking cumulus. Something to know about me... I love clouds. Kind of a shocker I know but I thought coming clean would be best.

[Meatyorologist]

Turning really dark to the west despite radar remaining relatively blank. I wonder if there's a cumulus tower shooting upwards faster than KATX scans. Would make sense since the best lift is now entering north Seattle, where the environment is quite primed.

[Meatyorologist]

It's about to pop off for sure.

[SunAndSnow]

Fun weather day. Hail looked like snow on 205 about an hour ago. Now I need to get the dog out for a walk during this sun break!