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11/23/04 FCST: MO,AR,LA,TX


Very good map...I was waiting for this map :)

After 22th low pressure will deepen, moving rapidly toward north-est and we'll have high probability of severe thunderstorms. If there will be a good cape, shear will be favorable for producing supercells and tornadoes, considering also that there will be a good advection of cold air at midlevel that will steepen the lapse rates.

The last time to chase before Christmas?
Post your ideas and discussions
Originally posted by Andy Wehrle
The Southeast can see some major outbreaks in November. Intense <985MB cyclones aren't all that uncommon during the month. It's just a matter of if the systems have sufficient Gulf moisture/CAPE to work with. When they do, watch out!





You're right Andy. Then now I see that GFS put down the low pressure that might interest better some states like LA,AR,Misissipi and TN.
In the older runs low pressure of 995mb was centered in MO: now in Westwern OK.

Depending on the instability, I can see the potential for a weak tornado associated with some low-topped storms in northwest and north central Texas, perhaps between CDS and SPS around 22Z. I might outlook 2% near the track of the vortmax if current solutions hold.

This all based on a quick and dirty scan of today's 12Z ETA. Lots of lift ahead of the system, widespread precip, and midlevel moisture forming a conga line of problems for this setup however, in addition to dubious return progs, weak sun angle, short day, bad climo, etc etc. This is a nice bonus for chasers already in the neighborhood.
I'm focusing on the neighborhood of I-20 in LA, as that's about as far as I'm willing to go for this, and it looks like it's gonna be a big soupy mess, with the outside chance of a decent short-lived and rather fast-moving cell or two burried in the mix. Not sure those odds are worth the 1,000 mile trip. Instability and moisture should be pretty good there. The problem is that shear isn't all that great, and the proximity to the low leaves something to be desired. It looks like it will amount to a poor-visibility, needle-in-a-haystack scenario in an area that's going to already be sopping wet. Yay, fun!
Originally posted by Morgan Palmer+--><div class='quotetop'>QUOTE(Morgan Palmer)</div>
ADMIN: Moved by Morgan Palmer... first to the wrong thread. Heh.

<!--QuoteBegin-Jeff Piotrowski
Tonight’s new 0Z ETA runs looks deeper and farther south with surface low and upper low. Target for 18Z Tuesday west of Waco is where the warm front and dry line setup. Cape 2000-3000 J/KG Waco south. Temps 70-75 dew points 60-65. Storms fire on the warm front around Lampasas TX 18-20Z move ne toward Waco 0Z tornado’s are possible.

The 0 line at 850 mb plunges south after 6z Wednesday into northern Oklahoma at the same time the 700 mb low and 850 mb low tracks ne toward NW ARK/SW MO from central Okla. putting KS/OK border ne into SE KS/ WSW MO heavy snow.

This could get very interesting would not be surprised to see moderate risk on Tuesday central Texas. :D
Tuesday could be a significant severe weather event for Texas in particular, but also areas further east. The thermodynamics and dynamics appear to be coming together. I am concerned about *too much* forcing, but the shear may be good enough so that the forcing wouldn't matter, given the north-south oriented dryline/cold front.
The 54 hour progs intensify the jets quite a bit, from the 48 hour progs,
would say Louisiana be seeing some good storms overnite.


I am going to wait until the next ETA run is out before posting to much of a forecast. I do see a good chase ahead however. We are extremely slow here at work so I may very well take off tomorrow if I can find someone else to split the gas bill. At this point I'm thinking a target of Tyler TX with the heightened chance of having to go south from there.

Well, things have certainly shaped up quite a bit. The shear and low proximity I mentioned in my previous post appear to have improved pretty significantly. I would still target Shreveport, LA, with the expectation of moving south from there. But I'm gonna sit this one out, because I think it's gonna be dark before things really get cooking there.
The 18Z mesoeta has slowed the system ever so slightly so that the surface low is forecast to be ~30 mi west of Fort Worth by 00Z.

This is good news for chasers who prefer central Texas over the piney woods east of I-45. This is bad news if you're sitting in College Station with a thesis you're supposed to be writing.

The 18Z mesoeta also forecasts a very minor secondary surface low moving up from Cotulla to near Victoria by 00Z. I'm not sure how much faith I can put in that forecast, but such a feature would have to be watched as it would back the surface winds even further in the Waco/Austin/College Station area.

It's hard to be excited about instability when it's 64 and raining outside, but looking at those temps/dp's south of the boundary (79/70 and partly cloudy in Victoria), I think we've got ourselves a nice unstable airmass heading this way.

As the 850 winds pick back up during the day, bringing in moisture off the Gulf, it looks like the ETA wants to break out a bunch of junk during the morning and early afternoon across the target area which would of course be bad. Hopefully this won't be a no-cap convection fest before the main show can get here, but midlevels are supposed to dry out quite nicely so if the atmosphere can remained untouched, we will be primed and ready.

Not to be a homer but I would put my target area near or just west of College Station TX on the nose of that screaming 500 mb jet and north of that potential secondary surface low. We'll have to play the waiting game to see where surface winds can get backed enough for some pre-squall supercells.
My problem is I am stuck with work related travel tomorrow. I will be sharing a rental car driving to Houston. Chasing is one thing being stuck in a car with disinterested neophytes while driving into danger will probably provide an angst fill day. I can only hope that the system moves into Texas late and that the site meeting is short. I hear that the cold front may not move out of new mexico until mid afternoon so delays in the systems movement are optimistic. As for the site meeting being short I am not optimistic. These affairs are always long winded and repetative.
To me, this now looks like the real thing down here in Texas. We have a sfc low, a warm front, inbound vortmax, and overhead jets, with plentyashear. Problem is we have lots of flooded roads so, not sure how I can chase it. For those of you with Weathertap access take a look at the storm precipitation totals and locations: http://www.weathertap.com/protected/gen/ra...ad_grk_pt.shtml. That's a lot of water. Anything south of a AUS / CLL line is in danger of being already under water or quickly becoming that way. Even areas east of ACT have received up to 5 inches.

So the question is not will there be storms, but will you have to chase them in a boat!

Hopefully my town will still be standing when it's over.

Good luck if you go out and be careful and mindful of the flooding road situation. :iroc:

Here is a link to Tx road conditions. http://www.dot.state.tx.us/hcr/main.htm. Sometimes that graphical viewer works, but lately it is very slow and overloaded.
Ill have to drag out the chase equipment and go with just a scanner and perhaps GPS for this one. Ill be keeping an eye on it here in Wichita Falls but looks to be that most of the action will be East and South of here. Very foggy here tonight.
IMO tomorrow's potential relies on helicity, much like the Nov 10 OK event. Models don't seem to be picking up on moisture very well, as it looks rather arid through 700mb per ETA. Obviously this won't be an issue since we'll need waders to go after this stuff. I did a quick spot forecast and have come up with a DFW/Stephenville/Waco triangle for starters. I really dig the UVV spikes stacked along this region, and although the forecast helicity doesn't look very good, I'm not concerned. I don't think helicity is possible to forecast in advance this far, so I'm waiting for tomorrow morning's runs and hoping for better results.

As with all systems this time of year, it's gonna be all about dynamics. CAPE is modest, but again that's not a concern as helicity will be the make/break element tomorrow. I'll make a decision by 12z or so and if it feels like love, I'll point my arse to the best 1km helicity with a side of CAPE.