11/5/08 FCST: IA/MO/AR/E. KS

[Aaron Gerhardt]

Looks like I get to start my first post here perfectly, storm chase on my birthday week!

Looks like the forecasting models started with some cautious optimism, to some very favorable conditions. Tim Jones and I are teaming up and targeting the central Kansas area, but from the looks we're a bit all over the place as to where exactly we're going to see our best chances. I know moisture was an issue earlier, but looks like we're looking better every update. I looked at the SPC outlook and it looks a bit more cautious compared to last nights one, some early supercell development to squall out and then kick it into gear and outrun us. Hopefully we get out there early enough to track the storms as they fire, and not have to miss out on initial development

Need to be on the ball on this one, first abroad chase for me. Can't beat the gas prices even if it's a bit of a bust.

 

[JF Massicotte]

Well if I had the chance to chase, I'd start the day in Wichita and refine my target from here, sure looks good for supercells and shear seems supportive of tornadoes... Wish you all good luck!

 

[Angie Norris]

Things are looking interesting for tomorrow afternoon. Moisture looks to be tolerable with the WRF (or whatever it's name is this week ) showing Td's near 60 by 0Z, CAPE 1000-1500J/kg, nice speed shear, and a Theta-e nose in the mid 330's. Vertical velocities are persistant in showing something blowing up just SW and N of the OKC metro by 0Z, before things line out by 6Z. Storm motion will be NE at about 45kts. It will just be a matter of hoping an isolated storm or two fires before dark before the line forms.
Current target: Chickasha, OK.

 

[Chris Lott]

Ponca City doesn't look like too bad of a target tomorrow afternoon, with a little more instability showing up in that area. It also seems the cap should be gone as well allowing for a few sups to take off quickly. According to the models I believe a few cells fire between the 1-3 timeframe tomorrow afternoon before quickly racing off to the east and turning linear. I'm still questionable about the moisture that some of the models show to be in place over parts of Ok. As Angie said, some forecast soundings are showing almost 1500 j/kg CAPE in parts of OK. Shear shouldn't be a problem with this one.

 

[mikegeukes]

Reading some AFD,HWO, Springfield MO mentions low level shear pose a risk of a few embedded tornadoes. Kansas City, mentions a few spinups with bows, Topeka says, I cannot rule out a few weak tornadoes, Wichita if any storms discrete, brief transient tornadoes a remote possibility. Tulsa mentions possible tornadoes with supercells. Summary, if a few discrete cells can form along and ahead of the dry line, there is a possibilty of tornadoes. Cold front overtakes dry line, squall line with damaging winds, and hail.

Tornado Climatology for November 1950-2007. (58 years of Data)
Number of Years with tornadoes for the following states of: IA, KS, MO, NE, SD, OH
Iowa: 7 years, Kansas: 12 years, Missouri: 20 years, Nebraska: 3 years,
Oklahoma: 23 years and South Dakota: 0 years.

Number of Tornado Days for November 1950-2007 (58 years)
Iowa: 9 days Kansas: 15 days, Missouri: 25 days, Nebraska: 3 days,
Oklahoma: 39 days, South Dakota: 0 days

Mike
Your source for weather links
http://geukesweather.blogspot.com

 

[Andrew Stoller]

Looks to me like one would need to stay fairly far south (south of Wichita) to stay out of the cold front. Forecast soundings for Wichita don't look all that great for supercells, but much better further south. The 00Z WRF (NAM, whatever you're supposed to cal it...) barely has any precip broken out and everything pops after that (after dark!). As it stands, I'd target Ponca City, OK.

 

[Bill Schintler]

Chase targets for Wednesday, November 5

Chase target (south):
El Reno, OK (10 miles west of Oklahoma City).

Timing and storm mode (south):
Storms will fire along the dry line by 3 PM CST. Supercells and a few tornadoes will be likely early in storm evolution. The best target may be the “tail-end Charlieâ€￾.

Chase target (north):
20 miles east of Yankton, SD (I-29 mile marker 31).

Timing and storm mode (north):
Elevated convection will be ongoing west of the area during the morning hours, and this will develop east and become surface or nearly surface based through 3 PM CST. A few embedded supercells along with a tornado or two will be possible; however, chasing conditions will be poor at best due to limited visibility from low cloud cover and widespread precipitation.

Synopsis:
A trough continues to dig S and E while a 80kt H5 streak rounds the base late in the period. Overnight, a 60kt LLJ will aid in the northward transport of moisture with 13C H85 dewpoints noted, although this will also result in a large region of ST in northern areas, which will inhibit insolation in the weak November sun. BL moisture will also be meager except in S TX. Soundings from TX through NE indicate SFC moisture of 50-55F and a 100-200mb moist layer.

By late afternoon, a CF will arc S and then SW from low-pressure in NERN NE, while a DL will extend SWRD from a CF/DL intersection near Salina, KS. Two areas will serve as a focus for severe WX, the first of which is just northeast of the SFC low where backing LLVL flow beneath a SWRLY LLJ will result in strong directional shear. Further S along the DL, discrete storms are likely early in storm evolution before a transition to a squall line.

Discussion (south):
Briefly: impressive shear parameters will couple with weak instability. As a result, updrafts will tend to be sheared off. Additionally, a nose of dry air between 3 and 8 Kft will override the DL, and may be detrimental to updrafts. A 100 mile wide axis of SC will extend along and E of the DL from KS S to the Red River, however sufficient SFC heating should still take place for MLCAPEs to increase to 750J/kg.

Discussion (north):
Diurnal heating will be weak with a large area of ST persisting over all of MN, the Dakotas, and eastern NE throughout much of the period. After 20Z, a slot of clearing will develop along and W of US-81 in NE while allowing for a narrow axis of MLCAPE AOB 500J/kg. Elevated convection will be ongoing by 12Z west of US-281 in SD and NE within the region of strong forcing beneath the left-exit region of the ULVL jet. Inhibition will rapidly decrease during the afternoon hours as H7 temperatures cool several degrees with the approach of the upper-level system.

A 50 kt LLJ will retrograde slowly westward as the upper-level system winds up, and SFC-3km SRH’s in excess of 300m2/s2 will result as this LLJ surges over backed SFC flow along and N of the NE/SD border. Deep-layer shear will increase to 50 kts by 22Z as the strongest ULVL flow overspreads the area. An SPC Supercell Composite parameter of between 1 and 2 is indicated, while a modest tornado probability may exist in areas with strong LLVL directional shear where parcels can become SFC or near-SFC based.

- bill, KD0DJG
8:45 PM CST, 11/05/08

 

[Brandon Lawson]

Since I don't have an opportunity to drive all the way up to the surface low, I will probably stick around home and see what happens around here. Latest NAM run has me thinking about going into northern Texas of all places. It shows precip. breaking out in an area of 1k-1500 CAPE values. This same area has slightly better dewpoints, almost southerly 850 flow, and slightly more veered 500 flow. Of course this is all based on the NAM and will probably change by tomorrow morning. Not to mention, the GFS does not agree with the NAM. But the latest RUC also shows a tongue of moisture poking its way into Southwest Oklahoma. At this point, the best southern target is anybody's guess. Will see what tomorrow's model runs have to offer.

The 00z sounding out of Gainesville, TX looks okay.

EDIT: The 4km WRF shows no precip. breaking out in Texas, perhaps I should reconsider lol

 

[Connor McCrorey]

I agree with Brandon. IF I can chase tomorrow, it will be here in North Texas. Instability is as good as anywhere, and nice, slow storm speeds around 25 kts will be great. Unfortunately I doubt I will be able to get out tomorrow, since I don't get out of school until 4:15 and sunset won't be too long after that. It sure would be nice...

 

[Erik Burns]

The Red River region ( Gainsville Tx- Ardmore OK and a bit further west )
I have been liking this region since yesterday runs.. Better Terrain, storm motions should be slower then further north, storm mode will be more discrete, better day time heating, better instability... I am going with the NAM on this one.. Not the best setup, but for November I will take it.

Precip broke out this morning in central TX and none of the models picked up on it.. So I will take my chances on the Tail end charlie.. Keep my fingers crossed.

 

[Aaron Dooley]

Tomorrow

I second that and I'm glad someone brought it up. Erik Burns and I were talking about the lack of focus for that area earlier. If the GFS swings more towards the eta/wrf in a few hours then good. If not, I'll be watching the mesoanalysis page for the parameters as I drive north tomorrow morning.

See some of you out there.

 

[Angie Norris]

I'm holding out for the Chickasha area. WRF is persistant in breaking out precip by 0Z. CAPE continues to look good at about 1000J/kg, and moisture looks adequate (not impressive, but ok...this ain't May, after all). I'll be checking out what RUC thinks in the morning, and adjusting from there.
Good luck to all heading out!!

 

[Jason Young]

I think I am going to stay in SC Ok. ( Davis to Duncan area ) . Even thought I feel I will end up in the NE part of the state . I do get the feeling this area will be more hail / wind down here.

 

[Andrew Stoller]

The forecast soundings for Oklahoma city and points to the south and northeast look pretty darn good! OKC at 00Z shows 1,600 J/kg CAPE, the winds finally have a backing component at the surface and quickly veer out of the southwest by 800 mb, SRH is 225.

I wouldn't be surprised one bit if there was a concentrated cluster of tornadoes tomorrow evening in northeast OK.

Anything north of OKC, more towards Wichita, and the cold front has already come through by 00Z.

Good lord, i can't believe I'm even contemplating chasing tomorrow. LOOOOOOOOOOOOOOOOOONG drive...

 

[Adam Penney]

I will be out chasing tomorrow for one last hoorah for the season. Will be targeting the area near Ponca City, OK as of now, but will readjust in the morning once I get a good look at the RUC. SE KS through NE OK looks to be the hotspot for any possible tornado action for the southern target. Best of luck to all that will be chasing tomorrow!