Long range model speculation

[Michael O'Keeffe]

I'm not worried yet either mainly because the GFS has been ALL over the place. I think this is the worst I have ever seen it perform everyday the low is in a different spot sometimes pretty far off same with the trough. It has shifted from a classic NEward movement out of the SW, then it had it coming out of the NW, then it had it digging well into Mexico. But at this point moisture is a bit worry some but it is still over 180 hours out which is pretty far even 84 hours is pretty far out.

The ECMWF however looks pretty epic and has been almost scary consistent compared to the GFS. More times than not the more consistent model will be the more correct model and the GFS almost always falls in line eventually. I remember the May 22-23, 2008 tornado outbreak looked amazing on the GFS til about 180 hours then the models had the system sitting over the Rockies not moving over the Plains and it looked like this up until it showed up on the NAM when it finally showed what the GFS did over 200 hours out. The ECMWF was one model that stayed consistent throughout the time leading up to that outbreak unlike the GFS. Just some food for thought.

Point is it is still pretty far out and chances are based on history that the ECMWF will likely be the way things play out good or bad with the GFS falling in line closer to the event. With that said like Brett mentioned the ECMWF doesn't have that annoying low form over the Gulf which one would think allow for much better moisture advection more similar to what we were seeing on the GFS last week.

 

[Eric Bucsela]

Agree with Brett & Michael. Moisture may be lacking initially, but with the trough digging in and a strong eastern ridge building - especially as depicted by the ECMWF - the weekend of Apr ~2-4 could be very interesting.

BTW, someone should start a thread for the first couple weeks of Apr, 'cause I don't see much exciting the rest of March.

 

[Chris Wilburn]

Agree with Brett & Michael. Moisture may be lacking initially, but with the trough digging in and a strong eastern ridge building - especially as depicted by the ECMWF - the weekend of Apr ~2-4 could be very interesting.

BTW, someone should start a thread for the first couple weeks of Apr, 'cause I don't see much exciting the rest of March.

Mods if you could change the title to read first part of April or something like that would be great. When I initially started this thread I was discussing the potential for the last week of March or so. It has panned out somewhat, but on a very small scale.

 

[Gabe Garfield]

It seems like the main reason for poor moisture return on the GFS is that pesky low that forms along the central Gulf coast mid-late next week, resulting in northerly flow over the GOM leading up to the trough's arrival. The 12z ECMWF is slower to move the trough into the Rockies, and has a nice big ridge dominating the entire eastern half of the country by the time that happens, which I assume means better moisture (though we can only guess without access to the moisture variables). In fact, I dare say the 500 mb pattern for next Friday-Saturday looks *somewhat* reminiscent of a couple nice late March 2007 events on this particular run.

I quite agree, Brett. In fact, I'm getting quite excited about the prospects for severe weather (and attendant chasing) for Easter weekend -- and beyond. What I like most about the Euro is that the progressive pattern we've seen for so long is forecast to end. Moreover, at the end of the forecast period, the Euro keeps the ridge in the SE US anchored while the atmosphere reloads with strong s/w troughs in the NE Pacific. If this happens, the 1-15 April period could be *quite* interesting.

Since the Euro is almost always the better model, and given its consistent solution (as Michael O. mentioned), I'd say there's a reasonable shot of it actually verifying. Of course, there is the usual caveat of using a single run to base your forecast. However, given the Euro's consistency and the favorable signal from the GFS ensembles, I'd say that good chase opportunities are, in fact, on the horizon.

 

[Mike Hollingshead]

Seems a few runs like the pinch the trough and get southerly mid-level flow as it comes out deal. 0z GFS looks better than before on moisture but still looks like an early tease system. 1st would be the day with good shear and late moisture with no instability. 2nd would be the day with good moisture, crap full continent southerly mid-level flow shear and subsequent rain fest/no instability. I just keep getting the feeling it is going to be one of those typical early season time wasting annoying deals. Ones you stare at each run from 300 hours out only to be off where it matters on the couple day ops.

I just already feel like mother nature's bitch on this one. It'd be nicer to at least see it look a little more classic a few runs than what has been showing. Least there is time for change and decent to good moisture hope. Also what is good is when I'm honest with myself I feel it doesn't look good, and I'm pretty damn good at feeling the wrong way lol. It's bad when feeling bad makes you just about feel good, all by itself.

My biggest prayer is for that April 1st/2nd system to not plow the good moisture that will be in place by then on down to South America.

 

[cdcollura]

Good day all,

I know it may be one of the first setups, but why look at the GFS (GooFuS) so far out?

These things tend to over-estimate moisture / instability so early in the season. Hopefully this will verify somewhat, but I like looking at the GFS no more than 48-72 hours from the actual "event".

 

[Mike Smith]

Whoa!

While I agree with the above comment about the GFS that far out, this caught my eye

Both the GFS and ECMWF are indicating something major the 1st through the 5th and while I do not think the specifics will verify, I do think that there will be the first significant severe weather event during that period.

 

[Mike Hollingshead]

Good day all,

I know it may be one of the first setups, but why look at the GFS (GooFuS) so far out?

These things tend to over-estimate moisture / instability so early in the season. Hopefully this will verify somewhat, but I like looking at the GFS no more than 48-72 hours from the actual "event".

Maybe because the pattern change was noticed out at at least 300hr on the thing? And more importantly.....why not?

How does one know the event is 48-72hr away while never bothering to look before that? Yes I know, spaghetti.

I don't think anyone on this board takes 180hr progs of moisture return as gold. More of a "hey, that'd be cool".....or bad. More than I'd wonder why one looks out far, I'd wonder why they post about it, like myself. I mean they know what is coming next lol.

 

[David Wolfson]

The 168hr system Mike shows is a bit too dynamic and moisture deficient for much rotating severe weather IMO. What it does do, however, is prime the Gulf moisture pump for the next upstream wave in the 240hr+- frame. I'd be looking at that as the kick-off of the spring season -- timing and severity TBD, given the long-range of the models.

 

[Bob Hartig]

Mike H., thanks--you've said it beautifully. I've been casting my eyes on the stuff--don't know if I can rightly call it one system--that has been showing for the first week of April. One thing that strikes me about it is, it's the first solid return of moisture that the GFS has consistently indicated this season. How it'll play out remains to be seen, but I'm hoping it'll be the thing that inspires me to make my first trip out to the plains this year.

 

[Brandon Lawson]

I think it is time to change the thread title to the ECMWF and the first 9-10 days of April

 

[Scott Sims]

How it'll play out remains to be seen, but I'm hoping it'll be the thing that inspires me to make my first trip out to the plains this year.
--Bob Hartig

As a non-Great Plains resident chaser, I agree 100% with this sentiment Bob. You and Mike have the idea right with these wishcast chart readings, why not? I want to be inspired to drive 5-15 hours just to be in place while thinking about the forecast, formulating my filming/photo goals, listening to great tunes and watching the familiar scenery of (insert your normal get there interstate routes here: 57,64,70, 55,44,40). I like the idea that i would get to stop and get the meal you want on the way out/back at the restaurant that you've ironically been to several times more in the last few years than some of those in your own town(Jack in the Box in Warrenton, MO on I-70 or Cuba, MO on I-44).
I also enjoy thinking for 7 days that I might need to be ready to go. The anticipation and minor prep is actually fun for me too anymore. I'd better get that oil change I have coming, stock up on road trip essentials, pay up my due bills and warn my ever so cooperative supervisor that my short notice time off request may be coming for any given day(s) starting with Apr 1 or so.

But, ultimately, all those that say that statistically it's a crap shoot out that far are pretty much right and I know it. So, I guess I try to look at a 100+ hour 500MB temp/wind/height contour chart like a lot of people do a good horoscope or a fortune cookie. They think: "Yeah that would be great if it happened, but I won't be holding my breath..."

However, I would strongly consider holding my breath, if I thought it would bring some deep moisture up in front of that trough!

 

[David Hoadley]

Just a reminder that a few of us, also looking at next weekend, live several days drive from the plains and MUST rely on the long range models --as well as appreciate their evaluations by the "locals." I especially look for general model consistency over several days. Of course, confidence increases with Day 2 and 1 but by then, we outliers have to already be half way across the country or it's too late. Each trip, I must decide *and* be on the road the morning of Day 3. Long odds yes, but success is all the sweeter.

 

[Mark Blue]

Well spoken thoughts David. If I'm not mistaken you live on the east coast, so to travel that far for plains chasing it must be studied and understood well in advance. I was watching the GFS runs yesterday and it appears the "pesky" low in the northern GoM may just be an anomaly as the southern most 500 mb isotach seems to be all over the place from run to run. The ECMWF doesn't appear to be having the problems the GFS is having with that aspect, so hopefully it's nothing to worry about. If we can get winds coming out of the right direction in the Gulf I'll be a happy camper and the post Gabe made stirs even more excitement that the pattern is finally changing.

I'll take a trough west / ridge in the east look any day as it signifies a fundamental shift in the overall seasonal weather pattern.

 

[Brett Roberts]

Quite the battle shaping up between the GFS and Euro tonight. The former wants to keep things more progressive, and the late-week trough becomes fairly sharp (with completely meridional upper flow over a large area ahead of the trough axis) as it moves out into the Plains early on Friday. The ECMWF, on the other hand, closes off a 500 mb low before the system even comes ashore in California, and it then lingers over the Desert SW for several days. The result appears to be a very interesting setup for Friday over W TX and possibly E NM, at least in terms of vertical shear (including directional shear, with nice 500-850 mb crossover).

Needless to say, moisture return would make or break this potential setup. As Edwards noted in last night's Day 4-8 convective outlook, having a downstream trough not too far off the east coast seems less than ideal, in addition to the weak upper low progged to sit over the Gulf next week. Even on the ECMWF, 850 mb streamlines passing through the southern High Plains on Friday look to originate from off the Mid Atlantic coast before coming across the Gulf. Of course, if the dryline sets up far enough west over high-elevation terrain, upper 50s to ~60 F surface dew points could be sufficient for a good chase day. Hopefully, after a few solid days of return flow, we can at least manage that.