FCST Disc: - 3/19/05 - Days 2&3 & Future Pattern

[Karen Politte]

I didn't want to post this in Target Area as it lacks a solidified forecast date - but I do believe the overall pattern of things is something we should be watching within the 7+ days timeframe. This can also go on from Rocky's thread in here, too......as a sort of add-on......and hopefully a little bit more optimistic!

I'll say up front right now that I am no expert model analyser - and as such I take a very simple look at things that are any more than 4 or so days out - but now is the time to start speculation with a hint of factual data.

I've just been star-gazing at the GFS - that's all, really. But it DOES show somewhat of a progressive pattern, I think you call it, with what looks strongly to me like a split-flow regime persisting probably into early April. From a look at the most recent 17 Mar 12Z GFS runs, it shows the southern branch of the jet stream becoming fairly active, with many disturbances, waves and kinks moving along it. This timeframe really livens up, it would appear, by the beginning/middle of next week.

In earlier runs, the GFS was showing a few shots at SW flow aloft, but the surface was still pretty screwy with southerly winds at the surface - but the fetch for moisture was out into the Gulf and BACK on shore around Louisiana!

Well - now, looking out to the 0Z Friday 25 Mar timeframe, I'm becoming a little more optimistic for at least a shot at the beginning of chasing, and perhaps some not-too-modified Gulf air. I think a large problem is that, as each disturbance crosses the area, it ploughs a front down through the Gulf way too far than I'd like to see.

But - it's only March.

Also - anybody care to speculate on what looks like a NICE wave poised on the west coast around the 0Z Fri Mar 25th time??

KR

 

[Gabe Garfield]

The GFS has been slowing things down a bit, with the first s/w trough expected to linger until Wednesday (or thereabouts), before finally ejecting to the northeast. The chance of severe weather is still there for that particular system, but I'd like to see a bit more moisture return before I get too excited about the potential for some really nasty weather in the southeast.

As far as the next shortwave trough (s/w) is concerned, I agree that this looks to be the real beginning of the chase season for southern plains chasers. The GFS has consistently developed another s/w trough to follow on the heels of the SE US s/w. The model has slowed its approach quite significantly, so I would expect that the impact of this system will be realized next weekend (instead of the middle of next week). Gotta love weekend chases! LOL

I am a bit concerned with how much moisture will be available, but the more the 2nd system lags, the better I think it will be (because moisture will be given more time to return).

Gabe

 

[Karen Politte]

I'm surprised that nobody is really talking about the chase prospects for Sunday, March 20th and Monday, March 21st. For Monday there is a nice-looking trough coming through which might spark off supercellular and possibly tornadic storms anywhere from SErn OK to NErn OK/Bartlesville area.

I don't have time to construct a compus-mentus Target Area discussion - but I wanted to throw the bone out there. We will likely be chasing unless something drastic changes.

KR

 

[Shane Adams]

We're on yellow alert for tomorrow, and watching Monday. I glanced at the ETA for tomorrow earlier and it showed absolutely nothing wind-wise upstairs - maybe 5mph from 500mb-through 250. Perhaps the fact that I use CoD (which is notorious for being screwed up) and the fact that I was looking at the ETA has something to do with this. That's what I get for getting too far ahead of things......morning of.

I'm heading down to Lake Texoma this afternoon to see my oldest friend in the world (been four years since our last meeting) and meet his new daughter, so I'll leave the model gazing up to my coherts tonight. I'll be driving back tonight as well, to be in OUN tomorrow morning early so I can start my analysis of what ATTM looks to be nothing but a warm-up chase for us tornado chasers. But, it should be relatively close to home, which is a welcomed change from recent years. Even if it is just March.

As for Monday, I haven't looked at anything. It will have to be a pretty spectacular forecast Sunday night for us to drive 3 hours east of here to merely set-up (then continue east even further from home as the storms race away). We've got the ways and means to chase it, but from a practicality angle it doesn't make much sense to chase Monday solely "because we can." Late Sunday's forecasts and surface obs wil determine our fate for Monday.

I'm eager for the season to get underway, but I'm not going to force the issue. I'm content to play around with tomorrow, but if Monday doesn't blow my socks off early that morning, I'll stay home, bide my time, save my money, and wait.

 

[Gabe Garfield]

Monday looks like the best shot at seeing tornadoes, IMO. The ETA continues to slow the vort max down, so C. OK might be game before too long. In addition to this, each run shows more CAPE for Monday (up to 2500 j/kg max now). With helicities > 300 m2/s2, supercells seem like a no-brainer (at least early on).

Gabe

 

[George Tincher]

Karen,

I think you are definately on to something about a very active week ahead. I have been browsing through various NWS AFD's and HWO's and the Jackson, MS office is calling for supercells, strong tornadoes and very large hail Monday evening into Monday night (Mar 21st). They have used the "outbreak" word also.

In addition, they say the pattern will remain active with another severe wx episode towar d the end of the week.

I haven't had a chance to read through all of these discussions. And for some reason the rap model page is down attm. So I can't say what may happen in other areas or if it will be in chaseable terrain. But I do feel the most significant severe weather outbreak of the season may take place around the beginning of this week. The SERN US may bear the brunt of it also, so hopefully everyone down there will be on alert.

-George

 

[Craig Maire II]

Possible chase Monday

If everything continues to look favorable my girlfriend and I will be taking off early tomorrow morning and heading down to Oklahoma to get into position for a possible chase on Monday...

 

[George Tincher]

Geez, things looking even more dangerous for LA, SRN AR and MS for the evening and overnight, with a good chance for tornadic storms along the Red River in NERN TX and SERN OK.

 

[Carrie Halliday]

Monday night looks dangerous to me also. I am not in the line of fire but sure hope those in the ArkLaTex are ready. :shock: Seems like the Yazoo City, MS area is a hotbed for them this time of year too. Hope their sirens are operational. I bid a "no thanks" to night chasing, thank you very much. I respect those who do, I just am too green to even attempt it. And a little skeered too.
Anyone going out to take on these possible night spinners?

 

[Angie Norris]

I seriously dislike model-casting...give me my day one charts and data anytime...but here goes...
I've been watching this since Friday. I'm surprised at the moderate risk for the day 2...guess SPC wants to make sure everybody's got a heads up on this. I'm thinking that central OK won't be involved on this one other than maybe some overnight/morning convection tonight and tomorrow. I'm thinking all the action will be east, beginning early afternoon-ish. Things should start out with some discrete cells, but I'm thinking we'll have a squall line blasting through Arkansas, some isolated tors ahead of the line, with the majority of this stuff after dark. I'd be keeping an eye out in the Arkalatex and Louisiana for good old tail-end Charlies...playing south on this might be the best option. Mississippi should see some Monday night storms if everything holds together.
A down side may be cloud cover inhibiting instability and making for a early-spring crap-fest as far as visibility is concerned. IF there is some clearing late in the morning, it could make things quite a bit more interesting. I'm not real impressed with the upper level support...I think I saw on the 500mb model some 40KT wind that might have some positive influence, and it looked like CAPE is progged to be close to 1750-2000. Hopefully, the cap will be just weak enough and there can be some heating to get things going.
Unfortunately, I've got school and work tomorrow. If I didn't, I think I'd be starting out in McAlester with the options of either east or south from there. However, if there's still a moderate risk, I may have to get a stomach virus :wink:
Good luck, safe travels and happy hunting to all who are going out tomorrow!! 8)
Angie