Tornadoes in Florida and Severe Weather on Sunday Night

Two things team:

1) It has been a fairly active morning in west-central Florida this morning. A nice MCS fueled by a nighttime LLJ and eastern moving cold front has produced a tornado or two (actually spotted, but also reported "numerous" times according to SPC's storm report page), along with other wind reports. Unfortunately, Florida is a crappy chase state, but hey...it's something to talk about this morning!

2) While this is only one severe weather index, it got me excited for some Sunday Evening Severe Weather (note: from twisterdata.com 12Z NAM 31 Mar 2011):

Also, here's a 12 Z NAM Mar 31 2011 sounding from Kansas City, MO (update of Chris's post, but with NAM instead since it's what I was looking at when writing this post, and GFS 12 Z wasn't done updating yet; also from Twister Data):

Also, can the storm track please shift north soon so that chasing can come closer to Madison, WI?

Helicity

Early Next Week (Apr 3/4)

Looking at the long range GFS (good for something)... things could get interesting in the IA/MO/NE region again on Sunday evening. The Euro-trash model has a completely different solution that far out, so there's too much model differentiation to say much about it attm. Just wanted to throw it out there as it will be worth monitoring early next week.

But, since I'm always thinking positive about severe wx... here's a forecast sounding for KC, MO on Sunday evening. GFS 0Z 144h .

Happy forecasting!

Chris 'Triple Point' Manzeck

Remember when.....?

Hey ganstas.... I came across this link to archived radar data... Its pretty sweet...feel free to reminisce about past major severe weather events as winter struggles to maintain its grasp on the upper midwest over the next couple of days..

http://devgis.srh.noaa.gov/Radar/index.html

- hailstone

Creston/Cromwell, Iowa Tornado: 3-22-2011 Severe Weather Outbreak aftermath: Photos, Video, and data

Hey Guys,

Here are a few of the photos we were able to take of the Cromwell/Creston, Iowa from yesterday. Tomorrow morning I will post a video with the full life cycle of the tornado and more details along with it. Not a bad start to the chase season 1-for-1 on the season :)

Enjoy,

Dan aka Squall Line


(Sorry for the shaky video, but had no time to set up the tripod)

Re: Severe Weather Outbreak prospects for 3/22/11

I found this interesting: the HRRR field for accumulated snow is actually picking up on what looks like hail swaths in IA, NE, KS and MO. Not sure if anyone else had ever seen this. And I'll take over on all those numbers as well ;)

(Although I didn't look at this scenario too closely to begin with since I had no possibility to chase it)

Good luck out there today Dan! Hope to see everyone out there sooner than later!

Re: Severe Weather Outbreak prospects for 3/22/11

Over/Under Prediction for Severe Weather Storm Reports for the IA-MO border region:

Tornadoes: 5

Wind: 37

Hail: *119 :)

Sincerely,

Helicity

Severe Weather Outbreak prospects for 3/22/11

Hey Chasers,

I had not seen anyone bring up the prospects of chasing tomorrow, and figured that I would throw out some thoughts in case any of you were planning on heading out tomorrow. I for one will more than likely be heading out after work (around 3:00pm cst) if everything continues to evolve favorably as model guidance is suggesting.

While the setup at first glance looks to be very promising, some very interesting questions are arising upon further analysis of ensemble model guidance.

Synoptic Setup: Robust negatively tilted upper level trough with associated 100+kt jet max ejecting across the Northern Rockies tomorrow. As of 12z guidance, the jet max and associated upper level support will reach the NE, IOWA, KS, MO area between 18z-00z. Evidence of the shortwave as seen in 500mb analysis will reach the aforementioned area around the same time as the jet max. At mid levels, strong mid level lapse rates associated with EML from Southern Rockies will advect into the Missouri River Valley this evening ahead of the developing mid level low. SPC SREF guidance gives greater than 50% probabilities of 700-500mb lapse rates greater than 8C/km associated with the EML. At low levels, 1000mb surface low will develop across Nebraska this evening by 6z ahead of the upper level trough and slowly track ENE tomorrow as it deepens to around 994 mb around 21z tomorrow centered approximately over Omaha, NE. Associated warm front will develop and strengthen this evening as it moves north across Northern MO into Southern Iowa. Boundary Layer dewpoints are forecasted to increase into the mid to upper 50s across central MO and MS river valleys by 18z tomorrow afternoon. The dryline will advance eastward and eventually be overtaken by moderate cold front into far eastern KS by evening tomorrow. It appears that convection along the developing warm front will begin late this evening and continue into the morning hours tomorrow. I agree with SPC that most of this convection will remain elevated through the afternoon hours tomorrow. Late afternoon/early evening surface based convection should be possible as upper level forcing advances in from the the W/SW. Given backed flow at the surface associated with the warm front, veering profiles with height, and CAPE values AOA 1,200 J/Kg any initial surface based storm development should be supercellular until the profile eventually become more unidirectional and storms grow upscale in some kind of mcs. The GO ZONE: In my opinion the best chance for catching surface based TORNADIC supercells tomorrow will be in the surface low, warm front, dry-line triple point (most surface forcing, backed winds, highest dewpoints, and closest to upper level forcing coming later in the evening). Given today's 12z model output, I would put that area in a narrow box from Omaha South to Topeka and East from Des Moines South to Marshall, MO with my GO ZONE being in the Clarinda, Iowa/ Maryville, MO area.

Chaser CIN (drawbacks and ?'s): It appears that the two largest inhibiting factors for tomorrow will be the northward extent of low level moisture and the timing of the upper level support. Latest model guidance is showing significant boundary layer modification (moistening) to occur across Northcentral MO/SW Iowa/SE Nebraska/NE Kansas to the south of a developing warm front later this evening into tomorrow morning. I am not fully convinced that greater than 55 td will be in place across southern Iowa in time for surface based initiation and believe there will be boundary layer mixing occurring throughout the late morning/early afternoon. This may pose a problem as temperatures in the warm sector south of the warm front are progged to reach the mid 70's, creating a td depressions greater than -10F. This would make only a very narrow corridor for possible "tornadic" supercells ie if they propagate to far north of the warm front they will be undercut by cooler drier air and if they develop to far south LCL and LFCs may be too high to get a funnel to the ground, great hail producers, crappy tornado producers. There are still questions as to the timing of the 300-500mb jet max and its location versus the warm sector. Unfortunately this one will have to be a wait-and-see tomorrow afternoon. If too late, the significant surface based stuff may not fire until around or after sunset, NO LIGHT= NO CHASING.

Ill leave this open for comment and debate. All in all though it looks like a fun and interesting day and would love to meet up with anyone that is planning on chasing across southern Iowa/Northern Missouri tomorrow. At worst there should be plenty of beautiful structure and pretty good chances for large hail. A little too early to put an over/under for tornadoes given the moisture situation.

Dan aka "Squall Line"

Opening Remarks

This will be the new home of UW-Madison's severe weather discussions. The authors will introduce themselves along the way. It ranges from Graduates, Grad Students to those who have ventured further for the PhD! 

If you are not a co-author, feel free to post in the appropriate section after the post, we WELCOME your questions, comments and ideas. This is an informal discussion with no correct answer, (at least not until after we chase the "Go Zone"). I'll let another co-author begin severe weather discussion as I am leaving for Colorado in 6 hours for Spring Break. 

Go bag a tornado fellas!

Lets hope for an active week, Supercells on the Plains and snow in the Mountains of Colorado!

"Convergence"