Its valid for Wednesday, April 17th, at 5 PM AST. Pretty cool, huh?
Its unusual to see a strong signal 312 h from the model start time as here, but especially so as we get later into the spring when the jet stream is slowing down all over the northern hemi and the troughs in it smaller, spaced more closely together, slower moving, too. (Summer is really goofy in that regard.)
Here, both the 00 Z (yellow lines) and 12 Z (gray lines) model runs in the past 24 h are indicating a big fat trough in the Southwest, and the bunching together of the red lines suggest a lot of confidence in that forecast. It would mean another real chance for rain here near this time, plus or minus a day or so.
The weather just ahead, Monday
In the meantime, our very next big trough, cold slam, and stupefyingly large low center, one that explodes from a tiny “Tonopah Low1” early on Monday morning, to one whose circulation extends from southern California to Missouri, virtually covering the entire western US! In spite of its gigantic extent, it still looks dry here, any rain accumulation here very “iffy.”
On the other hand, a half inch of dust accumulation is quite likely since it’ll be darn windy that day, dramatically windy. Likely to see more than 40 mph here in Catalinaland and visibility noticeably reduced in dust later on Monday.
BTW, its quite normal for low centers that are weak over the ocean to erupt into deeper lows as they move inland, during the spring. Just the opposite happens during the deep winter period when ocean lows move inland and weaken or die over the cold continent because they lose the temperature contrast that drives them. In the spring, the warming continent is “food for lows”, like spinach for Popeye (you remember Popeye, don’t you?). Ok, then in more modern terms, like that Hulk guy that got so gigantic when he got mad or something. That’s what happens in the spring to little lows and their troughs when they move inland, especially into the warm Southwest from the Pac NW.
The great news here, and I am so pumped about it, is that this giant low will be a whopper in terms of precip for so many droughty areas of the mountainous West and the central and northern Plains States. Check out the Canadian model here as an example of what’s coming to the Plains States. Just what the weatherman ordered. I’m sure it will make the news.
For reference purposes, a before you, if you will, here is the awful drought situation from the drought monitor folks in Lincoln, NB, in the central and Southwest US as it stands today:
Yes, this Monday’s low will be a billion dollar baby for some. And here’s where storm chasing is truly fun because of all the happy people you’ll meet in the rainy areas, not like those storm chasers who relish seeing tornadoes and destruction, as might happen farther to the south in Texas and across the South2.
Cirrus, thickening into a dull, kind of lifeless layer of Altostratus by late afternoon and evening, the latter a deep all ice cloud; no opening in it to the west for a great big sunset, nope, just gray all the way. Staring with sunrise:
We’ll see the end of our pretty Cirrus and Altocumulus clouds that we have this morning by mid-day to early afternoon. Enjoy them now. Might get a good sunrise bloom here in a few minutes, too. Hope so.
1Usually located on top of Tonopah, Nevada
2 “Truth-in-packaging”: Mr. Cloud Maven person chased Hurricane Carla in 1961, one of the 20th century’s greatest, ended up in Seabrook, Texas, near Galveston, and let us not forget the song about Galveston (has some wind in it) as a kind of distraction, so he’s being just that tiny bit hypocritical here.