3/4 FCST: Thursday Southern Plains

[Robert B.]

April 2, 1982

There was actually an F-5 on April 2, 1982...Broken Bow, Oklahoma. Twin supercells....debris from southern supercell lofted and deposited in damage patch of northern supercell. Amazing day.

 

[Jeff Lawson]

Good info on April 2, 1982 here. And yeah, the apparent similarities are a little unnerving.

I have tomorrow off, so I'll be on top of things. My plan right now is to probably hang here at home in the DFW area as long as possible, waiting for a particular storm to catch my attention. With the fast storm motion, intervening muck, and the potential for tornadic supercells all over the place, I don't think being out in the field right at initiation will do much good. Better to stay out ahead, keep an eye on data, and then go after the closest, best-looking storm I can get.

It'll probably make for a short chase, as I'm not going to follow anything into East Texas.

 

[Jared Mysko]

Come on guys, lets not forget that it was APRIL 2, not MARCH 4. We are one month early in the season.

I predict the first MAJOR BUST of the year! Let's not get too crazy here, remember how many tornadoes we have had in North America this week? ONE? TWO? 30 or 40 tornadoes do happen right out of the blue.

Of course, we may have to move off the continent if it does happen this early. Maybe we will see 200 tornadoes a day in May! We should ask some native elders if this ever happened before this early. This is very difficult to comprehend today when it has reached -28 C this morning in Saskatoon! I will certainly be watching Thursday afternoon from my Igloo in the Great Northern Prairies!

bored with snow in saskatoon

Jared

 

[Jeff Snyder]

Yeah, but the time of year does not matter if the synoptic setup is there. Granted, climatology does say that large outbreaks are very uncommon this early in the season, but then again, climatogology usually does not bring systems in of this caliber/type/etc until later in the season... How often do we get upper 60Tds in northerrn TX in March? Exactly...

Jeff

 

[Chris C Sanner]

Sounds like we have a jealous Canadian on our hands if you ask me :wink:

I'm going out and I'm still searching for my target. Dunno if there will be a target either. I'm probably going to find the nearest storm moving my way that looks decent and pick it up, because finding a storm tommorow will be pretty tough (similar setup to April 23 last year except for the fact storms will be racing this time)

 

[Jeff Lawson]

Come on guys, lets not forget that it was APRIL 2, not MARCH 4. We are one month early in the season.

Tornado outbreaks have occurred in this part of the country in January and February. The atmosphere doesn't keep a calendar. With a late Spring airmass in place (73/63 right now at DFW) and a big negative tilt trough crashing in, something's going to happen regardless of what month it is.

Of course, we ARE still a bit cool, so instability will be an issue - especially with clouds and precip getting in the way. But with the sort of shear and dynamics will be dealing with, any discrete storm that goes up is going to rotate. With any localized backing of the surface winds, the tornado threat is going to increase significantly. And if an area gets dryslotted during the morning and early afternoon (and it looks like just that may happen across Central TX), we may see better instabilites than anticipated.

Granted, the whole thing could go squall line right off the bat, but with such a blockbuster system crashing into such a juicy airmass with such good shear, a big event seems all the more likely.

I'm a big pessimist when it comes to these early Spring setups, but even I'm watching this one very closely.

 

[Jared Mysko]

Sounds like we have a jealous Canadian on our hands if you ask me :wink:

Correct!

I just wanted to get my 2 cents in on this! Looks like its gonna be a fun day for you guys down south, just be safe Ok?

Jared

 

[Jeff Snyder]

Just a cautionary note that was brought to my attention... ... This system is already behaving differently than the 12z ETA had forecast. It seems that there is a very large data void where the upper storm currently is located, and any analysis, much less any forecasts, seem difficult. Go read the DDC (Dodge City) Area Forecast Discussion for more info...

Jeff

 

[Matthew Hatton]

Yes be safe that's the main thing. I will be doing an armchair chase this time tomorrow although it looks like things might kick off earlier. I also notice on Weathertap that there is a decent southerly flow bringing all that juicy air up from the GOM at the moment. Is this setting the scene perhaps?

 

[John Cameron]

Very eery indeed...

Like to stay near WF but hope for some breaks in clouds...

Jeff

Good for you . . we aim to please :wink:

My day will begin around 2am :cry: That's why I dont get as excited about severe wx as those of you who actually get to "enjoy" it.

 

[Tim Marshall]

THURSDAY CHASE

Yes, tomorrow sure looks great on paper. There are plenty of positives like low-level moisture, tremendous lift, a great dry punch, and tremendous directional and speed shear. But are there negatives? Yes, cloud cover for one. Timing of the surface and upper air is another. Also, any storms that do form will be racing off to the northeast. It will be like trying to catch a speeding train!! I just hope that when I wake up in the morning there is not a squall line from Abilene to Del Rio. So, these are my concerns. But, I can't worry about it. The weather situation looks to good to pass up. So, I've already taken tomorrow off work and have cleaned up the cameras, and checked the batteries. I'm ready for the first chase of the year. Good luck everyone. TM

 

[Kevin Walter]

Thursday

The incoming wave certainly looks great on water vapor imagery, and it's muggy as can be down here in SE TX. Agree that the lack of real upper level data to feed into the models at this time may limit this system's predictability (but it may not even matter if we can't get model data anywhere). 00z soundins from across TX show decent lapse rates, so I'm not sure why model soundings keep tending to show horrible lapse rates (looks to be indicative of subsidence) in a layer between 500-400mb tomorrow. If that happens, we may be in for bust-city as shear rips apart CAPE-starved cu's that reach 20k' and fizzle. If the model forecast soundings are wrong, then we could be in for a show.

Either way, the A&M stormchasing team will be out in force tomorrow. We're tentatively targeting the I-35 corridor, but frankly we're just going to have to wait until morning to see. Either way, we plan on forecasting a location for initiation and then backing off of that about 60km to the NE, in hopes of picking off one of these storms before they leave us in the dust.

Good luck to everyone tomorrow.

 

[Kevin Scharfenberg]

I'm increasingly pessimistic about chasing opportunities Thursday. This system reminds me a lot of the high risk day on 6 April 2001, just displaced to the southeast.

The system is coming out very far south and with a slight negative tilt, so winds in the mid troposphere should back to nearly due south in much of the warm sector. This makes the shear profile actually quite marginal, about 40 kts of speed shear and very little directional shear in the 1 to 6 km layer.

The only area where there might be sufficient shear for significant supercells and tornadoes will be in the vicinity of the warm front, but I expect the area north of the front to be socked in with stratus and elevated thunderstorms in the morning. Given south to north storm motion, any storms that develop near or approach the warm front will quickly cross the boundary into the cold air.

I ran a Bunkers et al. storm motion estimate based on the 00Z eta for McAlester valid at 00Z tomorrow night, and right moving supercells are forecast to move out of about 210 degrees at 55 kts!! This is simply not a feasible chasing situation in such terrain. The best one can do, I think, is find a high spot and watch as a storm roars by.

I expect elevated hail-producing supercells to develop in the hill country up into southwest Oklahoma in the morning and spread northeastward. The storms developing near Midland currently should become more organized as they approach the metroplex and southern Oklahoma in the morning, eventually organizing into an intense squall line with embedded circulations.

 

[Jeff Snyder]

My concern is also the backed 500mb and above winds. The sfc to 850mb shear is awesome, but above that, the winds back with height. I'm hoping the 500mb low comes out farther north than SW TX, so as to veer mid-level winds across s. OK and n. TX... Again, though, I'm not putting toooo much faith in the models seeing how there is very little data collection near the low right now...

Jeff

P.S. -- this thing isn't going to do anything tornadic if the ETA CAPE forecast is correct... I mean, everything north of DFW has CAPE <500! Are you kidding me?! Yes, this is a dynamic system, but no way are we going to have long-lived, tornadic supercells with CAPEs ~250 J/kg... It's now a necessity that we get some clearing and sfc temps can warm up... otherwise we'll all be chasing weak, strongly forced, and strongly sheared storms moving at 70kts...

 

[Angie Norris]

Got into Norman a couple of hours ago...looks like tomorrow will be a decent day for a little field trip instead of sitting in the NSSL conference all day .
Gonig to check things out in the morning before making a final decision on a target, but the DFW area currently looks good for starters.
Good luck and safe travels to all who are chasing tomorrow!!

Angie Norris