4/01/06 FCST: KS/OK/TX

[samuel stone]

Descent 1000 mb surface cyclone looks develop across the central/southern high plains Saturday and set up a nice dryline through sw/sc kansas south through western oklahoma/eastern Texas panhandle and into north texas per 0z Nam model run, GFS Proggs surface cyclone slightly deeper at 999 mb. Nicely backed surface winds(especially east of where the dryline arcs back northwest) should result in more than sufficient low level shear supportive of tornadoes, and mid upper level shear is at least supportive, and in favorable orientation of the surface boundary to make supercells the favored storm type. Lots of instability(CAPE upwards of 2000 in some areas of western oklahoma). so everything looks great if storms can manage to initiate that is. I say that because cap still looks strong across much of the area. If we could speed up the progression of the upper trough just a bit this problem could be dissolved but I dont know if this is going to happen especially considering that if anything the models have trended to slow systems down a bit lately. 700 mb temps around 5-6 are on the brink of clear sky bust for this time of the year, and there is also a strong possibility that there will be some cirrus clouds overspreading the target area through initiation. So it appears to be some what conditional at this time as to wheather storms can develop but if they manage development they would be of supercellular character and have the potential to priduce tornadoes for the reasons stated above. Surface moisture appers favorble especially from Kansas border sout with 60 degree dewpoints up to atleast the Ks border(possibly further) progged by the 0z Nam.

All in all looks good but initiation again appears to be the main problem

Thoughts?

 

[Jim Bishop]

I agree that initiation will be the issue with this setup. But storms should fire across Northwest Oklahoma given the vort max moving through Southwest Kansas and a upper jet streak nosing into the area. It will be a late initiation, probably 4 or even 5pm. Curved hodographs support supercells with a few tornadoes given low to mid 60 dewpoints. I like the backing of both the 850 & surace winds along the suedo warm front near the Kansas border.

Being a Saturday I plan to be up there for this event!

 

[Jonathan Whitehead]

Based on fair amount of agreement in the models im going MODERATE for Saturday for NW. Oklahoma and W. Kansas
Here is my projected outlook:
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[Paul Knightley]

My initial target for my "virtual" chase will probably be in the Woodward area - certainly expecting somethin between Woodward and DDC. I wonder whether it'll actually turn into a Medicine Lodge chase?! That place often seems to be a great target in WF/dry-line set-ups.

 

[Andrea Griffa]

My initial target for my "virtual" chase will probably be in the Woodward area - certainly expecting somethin between Woodward and DDC. I wonder whether it'll actually turn into a Medicine Lodge chase?! That place often seems to be a great target in WF/dry-line set-ups.
[/b]

I agree with Woodward as the right target. As far as now I see something like a dry line bulge just out there. From there I would move toward Harper County KS that it's perfect with this synoptic(similar to may 12 2004)

 

[Scott Roberts]

Medicine Lodge/Coldwater is my iniital target, as well. Hadn't thought about the similarities to May 12, 04 mentioned in another post -- this stuck me as a "slightly south of there" setup. It'll be interesting to see how the outlooks evolve over the next 24 hours.

My initial target for my "virtual" chase will probably be in the Woodward area - certainly expecting somethin between Woodward and DDC. I wonder whether it'll actually turn into a Medicine Lodge chase?! That place often seems to be a great target in WF/dry-line set-ups.
[/b]

 

[Marko Korosec]

My initial target for my "virtual" chase will probably be in the Woodward area - certainly expecting somethin between Woodward and DDC. I wonder whether it'll actually turn into a Medicine Lodge chase?! That place often seems to be a great target in WF/dry-line set-ups.
[/b]

I agree on this one, an area between Dodge City, KS and Woodward, OK looks great to me! I would start in Woodward and then moving north towards Dodge city along the dryline. SPC issued MDT risk as well.

 

[Jim Bishop]

The setup looks better than yesterday, IMO, mainly because both GFS & NAM fire convection along the dryline across Southwest Kansas/Extreme Western OK. The NAM is probably firing convection since it indicates slightly cooler 850 temps. Both models continue to indicate a vort max ejecting into the Texas Panhandle and Southwest Kansas by 00z Sunday. From IR satellite I don't see a cirrus deck downstream to screw things up. Large scale acent with the upper jet streak, forcing from the vort max, and forcing along the dryline coupled with daytime heating should be enough to break the cap across Southwest Kansas/Northwest OK/Northeast Texas Panhandle. I'm still skeptical about convection firing further south across Southwest OK, but it appears more likely than it did yesterday. I don't want to flirt with the cap not breaking, so prefer to be around the large scale forcing.

The shear profiles are indicative of classic tornadic supercells with hodographs supportive of tornadoes. Tomorrow looks good and I think there will be tornadic supercells. My intial target is south-southwest of Dodge City near Meade, Kansas.

Game on!

 

[Michael P. Morris]

Based on this morning's forecasted BUFKIT profiles from the NAM and GFS, I believe the corridor between Alva, OK and Enid, OK shows the most promise regarding tornado potential. First of all, the cap becomes completely eroded wrt surface based convection by 23Z (yielding CAPE values in excess of 2500) so there will still be about 2 hours of daylight left for organization should it take that long for initiation. 0-3 km forecast hodographs indicate significant turning in the lowest layers, and 6 km shear vectors of 40-45 knots oriented roughly WSW will be supportive of supercells. 3 kilometer CAPE values ~125 indicate strong low-level buoyancy and should act to increase tornadic potential.

That being said, I have a lot of stuff to do this weekend so I will not be chasing unless something makes its way to my doorstep. I am rather excited about the way SPC has significantly increased their interest in this event even wrt yesterday afternoon.

 

[Mikey Gribble]

Right now I am planning on heading out of Wichita at 9AM for an initial target of Woodward. I plan on fine tuning the forecast from there before selecting my final target.
Everything seems to be coming together nicely. The 12Z runs have helped put my fears of a blue sky bust to rest. I am a little worried about getting good moisture all the way up to the warm front. The NAM shows a nice curved hodograph for Woodward by 00Z with CAPE >1500. Deep layer shear isn't to great until the mid level jet streak comes in later in the evening, but with shear AOA 35tks during the time period when storms should initiate, we should be just fine. I will probably play the dryline just South of the warm front, but I also like the Altus area in SW Oklahoma and I may get lured down there. The warm front area seems a little more appealing IMO because anvil level SR winds should be a little more favorable for classic supercells (5km SR winds appear favorable for tornadic storms throughout the warm sector). And god bless the slower storm motions tomorrow. I had all the fun I can take trying to keep up with those storms yesterday. 20--25kts seems stationary after that fiasco.

 

[Aaron Kennedy]

Moderator Note

Keep in mind the FCST rules:

(3) Prohibited content. Users may NOT post the following:
* Weather bulletins and forecast images, except as brief excerpts, in moderation, and with an explanation of their meteorological relevance;
* Links without an explanation of their meteorological relevance;
* Noise: posts containing only exclamations, salutations, witticisms, or personal anecdote (e.g. "I sure hope we get a storm. Bye!");
* Content containing no information relevant to the topic.

Try and avoid the: "Yes, I like Woodward as a target too" type posts. If the post contains no meteorological content, it probably shouldn't be posted at all. What would be ok is writing: "Yes, I also like Woodward as a chase target, but for the same reasons (list out what other people posted and/or add additional insight)

Aaron

 

[Chad Ringley]

12 UTC 12km WRF-NMM Central US Window run from this morning, available from this link:

http://www.nco.ncep.noaa.gov/pmb/nwprod/an...2/model_l.shtml

shows quite a bit of morning convection in E TX Panhandle/W OK from the 700mb Omega and 500mb Vorticity fields for tomorrow. The activity pushes into E OK/W AR by afternoon, and more convection fires along the dryline in W KS/N TX Panhandle by 00 UTC on 02 April, with further development with SWD extent into W OK/E TX Panhandle between 00-06 UTC on 02 April. Also, it appears the wind fields from the WRF run are weaker than the 12 UTC NAM run from this morning.

It seems the WRF is picking up on some of the discussed concern tomorrow, i.e., recover of boundary layer from overnight/morning convection, but appears to rebound quite well. The WRF agrees with Jim... afternoon sfc based convection initiates first with large-scale forcing across W KS/OK Panhandle/N TX Panhandle and then erupt with SWD extent into W OK as cap erodes. As highlighted quite well in Mead's 1730 2-Day Outlook, our old friend cirrus canopy might make or break tomorrow's promising setup.

That morning satellite image has been the subject of many a nightmares for me, and probably will be tonight for crews heading out tomorrow

 

[Todd Rasmuson]

i would be worried for folks not for us though as in a good
chance day but for property damage in south central/ southwestern
oklahoma tomorrow, looking at ehi index values across central ok of
near 4.5 and over 6 further into southwest ok, not to take away from
northwest ok but i think a area in sw ok from altus,ok to chickasha,ok
to norman,ok and north of a line from wichita falls,tx to healdton,ok
to just n of ardmore,ok to ada,ok i feel this area is best prime for
a possible tornado outbreak tomorrow, also this area from sw ok
into central ok by 0z has helicity values of near 350-400 tomorrow
evening. so bottom line i wouldnt discard to idea of nw ok totally
but i think best area of violent or possible large tornadoes forming
will again be in southwestern, southcentral ok and parts of nw tx
for saturday.. my guess on the day 1 to be issued early tomorrow
morning would be an upper end mod risk for my above mentioned
area i do feel mod risk could go as far e as i-35...

Todd Rasmuson

 

[Tony Lyza]

I think that there is a good chance that you chasers lucky enough to be able to chase on the plains tomorrow are going to get quite an outbreak. It appears to me as though there will be violent tornadoes in western Oklahoma. To demonstrate why I think this way, I have posted two forecast sounding texts links below.

0z Forecast Sounding Text

Altus, OK
Woodward, OK

 

[Chad Ringley]

00 UTC 4.5 km WRF NMM with no CP scheme used by the SPC...

http://wwwt.emc.ncep.noaa.gov/mmb/mmbpll/cent4km/v2/

strikes out with convection currently ongoing in the TX Panhandle, and unlike it's KF-scheme counterparts, does not have nocturnal convection at all during the simulation. Instead, it lights up the dryline like Christmas Eve at the Kranks with initiation coming at 21 UTC tomorrow afternoon, then consolidates the individual discrete cells into a line that moves across OK tomorrow afternoon. The WRF picks Woodward, OK and Pampa, TX as initiation winners.

Unfortunatley, this model runs is fast on its way to the trash can. Seems like the coarser-grids from the ARW and NMM may end up handling the activity developing near LBB better.

At least we get a glimpse at what life would be like tomorrow without a cirrus canopy!

EDIT: SPC 1 Day highlights 21 UTC as intiation time and the transition to a linear MCS that the WRF picks up on.....gangbusters! Good luck to everyone out tomorrow!