01/12/05 FCST: OK,TX,AR,LA

[Bill Schintler]

Chase target for tomorrow, Jan. 12

Sedan, KS; or about 50 mi E of I-35 at the KS/OK border. Timing: around noon. - bill

 

[Mickey Ptak]

Well according the the lastest ETA 12Z run that might be a good place to be at 18Z. It has precip starting in that area, cape around 1000J/kg and the surface low is right there in north central OK around that time frame. Unlike the last run the cap in that area, by 18Z, is almost non existing but any time before 16Z or so the cap will be very strong and that is a good thing. I think that could be a good place to start at least right now. Tomorrow morning analysis will paint the real picture.

Mick

 

[Glen Romine]

I have a hard time believing that the cold air in place right now over the suggested 'region of interest' is going to move as far north as advertised by the ETA model. I'd shift things south - relative to the suggested target of the KS/OK border. That said, I'm not sure I'd try chasing this event even if I lived in the area. Not really much to get excited about in my opinion.

Glen

 

[Mickey Ptak]

Originally posted by Glen Romine
I have a hard time believing that the cold air in place right now over the suggested 'region of interest' is going to move as far north as advertised by the ETA model.

I'm not sure I'd try chasing this event even if I lived in the area. Not really much to get excited about in my opinion.

Glen

Why do you think the cold air will not push as far north? I am just curious.

I will probably not chase myself because of work, but tomorrow morning will be the pivoting point in my decision whether I go or not.

Mick

 

[Glen Romine]

Originally posted by Mickey Ptak

Why do you think the cold air will not push as far north? I am just curious.

Models generally handle shallow cold pools very poorly. The model tendency is to mix out the cold surface air with warmer air above as the shear can be quite large across the poorly resolved boundary - and the model solution to large shear is increasing mixing to maintain stability, and this process can exceed phyisically reasonable rates. The atmosphere may well prove me wrong (sure wouldn't be the first time) - but I can recall past experiences where moist and shallow cold air just doesn't like to move, with persistent drizzle reinforcing the boundary. Just looking at the current temperatures compared with the 12Z model forecasts suggests the ETA is warming too rapidly in this region. RUC model, which has better resolution, also is slower than the ETA in bringing the warm front north.

Glen

 

[Doug Lee]

Somehow, this is starting to remind me too much of April 19, 2003. That day was cool, damp and drizzly, and the early HWO's kept calling for severe to develop. Then the 1 PM HWO mentioned the dryline was pushing east, right before the Tulsa NWS called for a Skywarn activation. A tornado hit Dewey and killed 2 or 3 people.

I'm just a great big ray of sunshine, ain't I?

 

[Robert Dewey]

Originally posted by Douglas D. Lee
... A tornado hit Dewey and killed 2 or 3 people.

I'm just a great big ray of sunshine, ain't I?

Damn, where was I? LOL

I'm still betting on a squall line... Haven't checked the latest 18Z data, but I'm sure it's very similar to the 12Z run. I would say that east central OK would be the best bet -- Right on the nose of warm air, decent instability, weak CAP, and good shear. That's where storms will likely be supercellular to begin, rapidly translating into a squall line...

 

[Jim Bishop]

The 00z Wednesday ETA run looks terrible. Vort max is very elongated. this is not the same setup I had hoped for, and the models had been slowly leaning towards this solution. Not too mention the cirrus deck that's moving into the plains and will be over the eastern half of Oklahoma. That certainly won't help the rather thick stratus deck that is currently draped across much of Oklahoma. Not to say there can't still be storms in eastern OK which are initially supercells. But they will quickly evolve into a squall line.

I can't justify the long drive up there. Looks like a no go for me. Rats.

 

[Kelley Austin]

Well, here is my shot at it. I think initation will be around 4:00 PM about the OK, AR boader. Due to a thin and broken cloud cover east into AR with daytime heating into the mid 70's and plenty juice a few sup's will get going really fast. The squall line will develop along I-30 north east into south east MO. with a few embedded tor's. Bows and wind will be more the norm for this one.

That's my 2 cents worth. We'll see. If they are out there I will be too.

 

[Glen Romine]

Originally posted by Douglas D. Lee
Somehow, this is starting to remind me too much of April 19, 2003. That day was cool, damp and drizzly, and the early HWO's kept calling for severe to develop. Then the 1 PM HWO mentioned the dryline was pushing east, right before the Tulsa NWS called for a Skywarn activation. A tornado hit Dewey and killed 2 or 3 people.

I'm just a great big ray of sunshine, ain't I?

Are you sure about the date? I did a quick search and found this site with some plots of weather conditions for that event:

http://www.hookecho.com/events/2003/04_19_...9_03/041903.asp

Scroll down the page a bit and you should find them. I really don't see many parallels at all between what is forecast for tomorrow and that event.

Tonight's ETA run suggests high to mid-level clouds will be over much of OK, a sharp front will struggle to push north of the KS state line, with a dryline dropping from the low, which may have a limited push for lack solar heating. Surface moisture forecast by the ETA to mix out strongly - with only upper 50 dewpoints reaching ne OK. If better moisture is present, then you might be able to bump CAPE forecasts up a notch, which are only in the 500-750 J/kg range right now. Surface winds actually look better this run - but the strength of the deep layer shear may be too much for the limited instability. Convection in the warm sector may not develop until the cold front starts to swing in behind the low after overcoming the dryline - near darkness - around extreme se KS to ne OK. Some severe hail reports look possible early, then as the front begins the push and upper flow becomes more perpindicular to the boundary, a squall line looks likely to develop late over western AR and could pose an increasing severe wind threat. This is how I see it at least.

Glen

 

[Bill Tabor]

Originally posted by Jim Bishop
The 00z Wednesday ETA run looks terrible. Vort max is very elongated. this is not the same setup I had hoped for, and the models had been slowly leaning towards this solution. Not too mention the cirrus deck that's moving into the plains and will be over the eastern half of Oklahoma.

I agree after the 0Z run it doesn't look as in sync between sfc and mid level plus the area seems to be pulled a bit further east with elongation. The area I mentioned in se OK may still see some action, but certainly not as good as organized of a day chase situation in chaseable landscape. Without further analysis and improvement I'll probably let this one pass unless somehow there is a tail end north and east of ACT in which case I may investigate.

 

[Bill Schintler]

Chase target for Wednesday, January 12

Chase target:
Coffeyville, KS.

Timing:
Storm initiation 11AM.

Storm type:
Isolated “low-toppedâ€￾ supercells early in storm evolution, which will track rapidly to the NE at nearly 50mph. Hail to golfball size, and a few weak (F0-F1) tornadoes will be possible. By early afternoon, storms will evolve into a squall-line with severe wind to 70mph the primary severe threat. By 00Z, this line will be approaching a Harrison, AR; to Hot Springs, AR; to Dallas line. All-in-all, not an ideal chasing day given the rapid storm speed and extensive low cloud cover that will be in place.

Discussion:
00Z analysis shows a 150kt jet streak approaching SRN CA which will round the base of the WRN US trough tomorrow. By 12Z-18Z tomorrow, the left-exit region of this streak will lift into the FA. Associated with this feature will be a 700mb-trough axis aligned along a Grand Island, NE; to Dodge City line. Surface low-pressure will track along the OK/KS border during the day along the strong temperature gradient there. The FA will remain strongly capped until mid-day as cold mid-level temperatures approach with the mid-level trough/shortwave, and 700mb temperatures drop to –0C, and 500mb temps drop to nearly –20C.

The $1,000,000 question is that of the degree of thermodynamic instability that can be achieved in the FA. The large negative factor is the shallow cold and damp airmass that is in place on all but SERN OK that will be very difficult to scrub out despite the WAA that has commenced. A strong LLJ is already in place just above the BL: 00Z 850mb analysis already shows a 40kt SWRLY LLJ transporting 16C(61F) temperatures as far north as I-40 between AMA and OUN. Even the 925mb level shows a 35kt LLJ nosing into OUN where T=10C. The OUN sounding also shows Td=10C at 925mb; while LMN shows T/Td=9C/9C at 900mb, with a surface T/Td of –2C/-2C. The 00Z Eta has initialized a few degrees cool in SWRN OK with temperatures and dewpoints well initialized elsewhere. It has also initialized well with regard to 00Z temperatures throughout OK. Based on this and the fact the Eta does best at handling shallow cold airmasses, will go with that model. A marginally unstable MLCAPE approaching 700J/kG is suggested during the afternoon hours. Even if surface temperatures verify a few degrees cooler then guidance, the excellent mid- and upper-level dynamics which will be very conducive to rotating updrafts should be able to make up for January CAPEs.

- bill

 

[Dave Crowley]

Originally posted by Douglas D. Lee
Somehow, this is starting to remind me too much of April 19, 2003. That day was cool, damp and drizzly, and the early HWO's kept calling for severe to develop. Then the 1 PM HWO mentioned the dryline was pushing east, right before the Tulsa NWS called for a Skywarn activation. A tornado hit Dewey and killed 2 or 3 people.

I'm just a great big ray of sunshine, ain't I?

No one died in Dewey, OK on April 19 2003 from a tornado. Not that I can remember, or find info on.It was to the north of town, and only a few farm homes were hit as it tracked towards Wann. We got a brief glimpse of the tornado a few miles N of Wann.
You might be thinking of a different date. it's been awhile since anyone was killed by a tornado in NE OK. June 1 1999 is the last one I can think of.

 

[David Schuttler]

2 Horses died back west of B'vlle in Osage County From this one I believe

 

[Doug Lee]

I may be wrong, but for the time being I'll stick by my original post.

I was right by on of the lead ham radio operators for Tulsa Skywarn, when he checked the updated HWO that mentioned the dryline pushing east. Next thing, the Tulsa NWSFO calls him in. Since the NWS was on my way home, I decided to go up and sit in as a logger. Later, this guy points to the radar around Dewey and says that someone there is getting hammered. After I get home I find out from the local news that a house collapsed and, I believe two people died inside.

Now this situation may not be lining up just the same as April 19 as far as the numbers go, but I do see some similarities. Gernerally, when we have overcast and rain, severe weather does not follow. That day the dryline was the catalyst that provided the lift, this time it's probably the upper air circulation.