Nerman
Member
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Pattern January 2020 - Operation Thaw Alaska
- Thread starter KyloG
- Start date
baroowoofr
Member
Where did you get the aam forecast?
It makes sense though when he was talking about the STJ collapse. If that's the case with northward momentum transport shouldn't we possibly see this at least try to go north and spike the pna/epo
Webberweather53
Meteorologist
He's talking about Global Wind Oscillation (GWO) phase space (and again the GWO is basically just AAM + the tendency of AAM).
When you're in a state of high-very high AAM which is often the case when you have central pacific-western hemisphere tropical convection, frictional torques will act to dampen the AAM anomaly, negative mountain torques will thus commence soon thereafter, and the positive angular momentum anomaly will begin to propagate and be dispersed poleward along mid-latitude wave trains. Retraction of the Pacific jet often occurs during this period of time, which can favor at least transient periods of North Pacific blocking (i.e. -EPO). This is exactly what we'd want to see to send the entire N American continent into the freezer later in February.
baroowoofr
Member
Webberweather53
Meteorologist
Thanks for the link, I occasionally use N IL University's website.
I thought that site was dead...thanks guys!
Webberweather53
Meteorologist
The GFS also has a significant -AAM bias that becomes particularly evident in the medium-extended range, this goes hand-in-hand w/ the -EPO bias we often see on a regular basis from this model because -EPOs are favored when we see a GWO orbit from high to low AAM
Nerman
Member
Big jump N with the precipitation getting into GA.
Ilovesnow28
Member
Always 300 hours out yep
Would be a pretty cold (40s) rain for @pcbjr and El Ninolike during this strong +AAM, where the coldest anomalies in the entire country are down in FL then and the next day further south with only 50s in the early afternoon with the rain then there. That's quite chilly for S FL (as much as 15-6 BN).
Nerman
Member
That area was non-existent of a storm 2 days ago. Now it's moved over 100 miles North in just 18 hours of GFS runs. The Euro made the jump too. I'm not sure if it can get far enough North to the freezing line but it's starting to get 'that look'. I'd love nothing more than to get a surprise inside 5 days during this crap cold dry/warm wet pattern we've been in.
The end of the GEFS continues to look pretty similar to most of the LR GEFS progs so far this season...some ridging along the west coast with a trough through the center/eastern part of the country and the PV sitting over Greenland. The GEPS, as has also been the case most of the season, looks a bit better. Don't have access to the 360 EPS, but I assume it probably doesn't look better.
850s through the period look average, to slightly below, depending on your model of choice. So, it's not a torch, as others have said, and it's possible to sneak an event in here somewhere. But I'm just putting lipstick on the pig by saying that. We need something to shake up the pattern before the clock runs out. In mid-December, we were looking at early Jan, which became mid-Jan, which turned into late-Jan/early Feb. Now, we're likely out to mid-Feb before a better pattern sets in, if it does.
Maybe the GWO/AAM will help force a change, at least for a while. I don't know. The ensembles at range have been fairly useless this year, IMO. I'm sure the EPS has done the best, but it's still whiffed a few times. Basically, nothing showing a cold and wintry pattern has played out. The CFS is hot garbage. The JAMSTEC is a mess. The JMA is a dumpster fire. The only thing that's been a reliable longer range predictor is persistence, once winter started.
I still think (hope) we get into a one or two week pattern where we get some blocking somewhere across the north that will provide a sustained cold air feed into the eastern US. But I'm not really sure how we get there in time, at this point.
850s through the period look average, to slightly below, depending on your model of choice. So, it's not a torch, as others have said, and it's possible to sneak an event in here somewhere. But I'm just putting lipstick on the pig by saying that. We need something to shake up the pattern before the clock runs out. In mid-December, we were looking at early Jan, which became mid-Jan, which turned into late-Jan/early Feb. Now, we're likely out to mid-Feb before a better pattern sets in, if it does.
Maybe the GWO/AAM will help force a change, at least for a while. I don't know. The ensembles at range have been fairly useless this year, IMO. I'm sure the EPS has done the best, but it's still whiffed a few times. Basically, nothing showing a cold and wintry pattern has played out. The CFS is hot garbage. The JAMSTEC is a mess. The JMA is a dumpster fire. The only thing that's been a reliable longer range predictor is persistence, once winter started.
I still think (hope) we get into a one or two week pattern where we get some blocking somewhere across the north that will provide a sustained cold air feed into the eastern US. But I'm not really sure how we get there in time, at this point.
Six Mile Wx
Member
CFSv2 For what it’s worth
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Any bets on what this looks like on verification day?
1. Based on history/analogs, I expect the SE will experience a 2-3 week long BN dominated period but patience would be required imo as I think this wouldn't be til somewhere between 2/20 and 3/20.
2. Ask and you shall receive fwiw:
A. 12Z EPS hour 360 500 mb/sfc: cold W US/warmth hanging on E US
B. 12Z EPS 2 meter temps hour 360:
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Cad Wedge NC
Member
That 500mb pattern does not match the surface temps in the least...... something is off here.
Cad Wedge NC
Member
18z GFS is coming in deeper and colder with the Friday system.
It does look strange, the 0z geps had something similar