03/12/06 FCST: Southern Great Lakes to Western Gulf Coast

Well, it appears that significant moisture (Tds 65-75) will move northward out of the Gulf starting tomorrow. With continued troughing in the west / Rockies, southerly flow should pump warm, moist air into at least the eastern sections of the southern plains. Model solutions are not in agreement very well, as the 12z NAM continues to show no organized cyclone in the Plains on Sunday, with a broad area of low pressure in sw KS, the OK/TX panhandles, and se CO. On the other hand, the 0z GFS and ECMWF show a ~990mb low in northern KS by 0z Mon (Sun evening), while the 0z UKMET has a weaker low (~1000) in central KS. Given the number of solutions favoring at least a moderately-strong cyclone in KS on Sunday, it's tough to buy the NAM forecast yet. Last night's NAM showed an elongated area of low pressure along the OK/KS border, with sw sfc winds across OK/TX/AR/LA; this morning's 12z does away with this, and brings S-SE winds across the warm sector. Nearby NWSFOs mentioned svr convection possible from se KS southward (OUN mentions possible in their eastern CWA), so it appears that they aren't buying the NAM solution.

I won't go into much more detail, since it is 72hrs out. I do hope moisture can work it's way westward a bit more, since I'm not a fan of chasing in NE TX or AR... However, spring break begins today, so I'm not too worried about being out late Sunday.

EDIT: Current Day 3 outlook outlines a high-end SLT event (30% hatched).

EDIT2: 12z GFS indicates the dryline will be located near a Dallas to east-of-Tulsa to east-of-Kansas City line by Sunday afternoon/evening. As it stands now, if the GFS verifies with it's more westerly moisture, I'll go. 500mb flow is progged to be very strong, with >80kts northwest of a Childress to Kansas City line, meaning incredibly fast storm motions, though it'll also translate into strong shear.
 
Quick model round up for 18:00 CDT Sunday

03/11 00z GFS
Surface Low 994mb over Topika
100 knot plus 500mb winds across Tx Panhandle, South to North East Kansas. Quite well defined dryline, DFW to Joplin to East of Kansas City.
Dew points 65 plus along DL down in Texas to upper 50’s towards Iowa.

03/11 00z ETA
Surface Low 997mb over Great Bend, KS
80 knot plus 500mb winds across TX Panhandle, SW Kansas to NE Kansas
DL East of DFW to Springfield to further East of Kansas City
Dew points 60 plus along DL right up to North Missouri
750m2/2 !! of DLS over a wide area of Iowa.

In summary the ETA suggests that by 18:00 CDT the best flow will be out of phase with the instability – while the GFS says that it will be in phase.

Too far out to call anyway.
 
SPC throws out huge MDT risk out far the majority of MO/AR/IL/IN. Suggesting the potential is there for a tornadic outbreak. I won't look at the models in depth until Sat. evening, but looks like a great day, considering this system will usher in a more tranquil pattern (good news and bad news).

I may need a nowcaster on this one to give me adequate time (I'll edit this out after I get some responses).

I'll also need to look at the possible movement of storms after the 3/11 event.

Edit #1: Thanks to those with their input on the terrain in MO. I'll take that into consideration Sunday.
 
One big thing that could throw a wrench into Sunday's severe..... a giant inversion. I've been looking at BUFKIT soundings for Kirksville, St Jo, and Burlington, and they all seem to have a huge inversion with CINS well in excess of 100. Almost everything else is very favorable, but the storms may not even form.... and if they do, right now i would see them only as elevated.
The best bet for low CIN looks to be near Kirksville from 4pm-6pm. The CINs lower to around 50 J/kg or so. Lets hope that the warm front gets some action and maybe tomorrow wont go bust.
 
12Z Canadian this morning has a 991mb low moving into NC/NE KS by 0Z Mon with precip between KC to Sedalia. Other models (NAM) have also slowed it a bit, so my thoughts are thinking for tornadic between KC and Columbia, with Saint Louis getting hit mainly during the evening as the line congeals and moves east.

This is starting to look a bit like a certain severe weather day...just a little weaker (that I will not name) in Missouri a few years ago. LIT has been talking about it in their AFD and mentioned it as well.
 
Another problem with sunday... it doesn't look like the dryline is forecasted to move much through the day. It appears to me that the NAM keeps it in western MO until after dark when it could be overrun by the cold front, it then moves eastward reaching St Louis by around 6am.
Those are probably the two biggest reasons right now that the NAM is not forecasting dry line precip...
 
Tomorrow is looking very good for portions of the Midwest and Ohio Valley.

The warm front actually pushes up into southern lower MI SSUN night into early MON morning. T's increase to the low 60's with Td's not far behind, so LCL's will be pretty low. Directional and speed shear along the warm front will be very impressive as well...

As of right now, I would say the best TOR threat is along the warm front, as the GFS has SWerly winds all across the warm sector. Right now, it looks like the most active tornado areas will be around IA/MO eastward through OH around 00Z MON, spreading NEward into parts of northern IL/IN/OH and southern lower MI between 06Z and 12Z MON (with cold frontal activity later MON). GFS streams in decent SFC-based instability along and south of the warm front, even in the night time hours, so I'm not concerned about that.
 
One thing to note... I'd stay away from the NAM output. It is by far the odd man out, with ALL of the other models showing a single low pressure system dominating. In fact, the NAM solution would keep lower MI locked in near-freezing temperatures with ZR, where the GFS/GEM puts us into the 60's with a TOR risk!

I'd be very suspicious of the NAM's output.
 
NAM vs. GFS

Once again there is a conflict between the NAM and GFS. While the NAM has northeastern TX looking like a sure bet, the GFS counters that with showing less than or equal to marginal shear. I like the 65+ dewpoints and the directional and speed shear of the NAM, however with great differences in both model runs I would wait to see the RUC output. I think we will have a better idea of which forecast will be verified by the 00z run tonight and tomorrows 12z.
 
http://www.wxcaster.com/modelskewt.php3?mo...&STATIONID=kirk

That forecast sounding for Kirksville, MO at 21z tomorrow pretty much says it all for the warm frontal zone across northern MO/westcentral IL -- with widespread 2000j/kg SBCAPE overlapping 250-350m2/s2 0-1km SRH by the mid-afternoon -- owed to very strong boundary layer veering, yielding the incredible hodograph curvature and the incredible storm-relative helicity. You won't often see large SBCAPE available in northern MO/westcentral IL in early MAR very often, that's for sure. Obviously, the biggest problem tomorrow will be the storm speeds -- with a solid 45-55MPH average.

But, this is not keeping me away... I'll be leaving for westcentral IL to start in a few hours... Peace.

* edited to correct mis-phrased
 
HIGH RISK ISSUED...First of the year! I am issuing my outlook and will get back to you guys shortly. I am expecting long-tracked tornadoes and perhaps an event for the March record books.
 
Originally posted by Alex Lamers
HIGH RISK ISSUED...First of the year! I am issuing my outlook and will get back to you guys shortly. I am expecting long-tracked tornadoes and perhaps an event for the March record books.
Personally, due to expected tremendous shear, good instability, which leads to almost extreme EHIs, I would anticipate several violent tornadoes ala 3/1/97 only farther north.
 
Backyard chase tomorrow. Don't know about you guys, but it's a double edged sword having a high risk over top of you. All of the pieces are falling into place for what could be a major outbreak tomorrow. GFS and NAM in fairly good agreement with the location and timing of initiation. Just hope any tornadoes that do form stay out in the open fields of northern Missouri. Thankfully, that area is mostly rural. Current plans are to head north to Macon and stage there to either run west on US 36 or north on US 63 both of which are four lane roads now, thankfully. Will obviously take a peek at the 12Z runs in the morning before heading out. Best of luck to anyone chasing tomorrow and prayers that no one is injured. Be safe!!!!!
 
My very quick thoughts.

SPC has issued their first high risk of the season.

My target after taking a really quick look...


Pulaski, IA to Greenlop, MO to Warsaw, MO

Just look at the soundings....WOW!
 
Ill be playing the I-70 corridor east... whens the last high risk issued for march? i hope tommorow doesnt spell disaster for people but the way it looks now its going to be one.... i cant really pick a target out yet until the next model runs ... good luck to everyone tommorow... stay safe and i will do the same 8)
 
Glad I chased and stayed in this area of IL overnight. Now that my prediction of the high risk has come true(ref forcast for IL thread); i hope that everybody involved in this tomorrow is safe. This will not be a bust. Snowstorm for upper midwest, 40 degree temp contrast from MN to IL, high shear levels, adequate dewpoints, powerful jetstream 100k +!

Everybody is coming this way right now aren't they.

Remember that with the beauty comes the beast.
We are here to save lives today.
Enjoy this one! Be Safe!
 
Originally posted by Jason McIntosh
This will not be a bust.

If there's one thing a chaser should never say about a day it's that... :lol: I've seen many HIGH risks bust either in regards to no convection (clear-sky bust) or to too much convection (squall line or mess bust). I don't think it'll be a clear-sky bust, but you never know if you'll have too much forcing or whatnot to end up with too many storms. I do think it could indeed by bad, it I certainly don't know for sure. The setups that accompany extreme severe events (those that are usually outlined by a HIGH risk) tend to be extremely volatile and very sensitive -- a little too much forcing or a little too weak (or strong) a cap may be all that's necessary to make or break a good chase day.

At any rate, I've opted not to bite on the HIGH risk target. Too far for too fast storm motion in too unfamiliar area and too early sunset has dissuaded me from heading into N MO. So, I'm preliminarily heading one of two places: ne OK / sw MO or northern TX. Shear is progged to be stronger the further one goes towards northern MO and western IL. That said, storm motion is progged to be in the 50-60kt range in MO, which is a little concerning. Farther south, N TX should have nice Tds with potentially higher CAPE. Unfortunately, 850mb wind minima noses into northern TX by 0z, resulting in rather weak shear. On the plus side, the area of N TX between I35 and Paris isn't bad chase country... I guess I'll nkow more tomorrow when I look at some RAOBS, satellite, and latest nwp guidance.
 
My targets are St Jo from 12-3pm.... Bethany area around 3pm.... Unionville and Centerville aroudn 6pm....
Lots of places in central Missouri may not see much til late.... maybe after dark. Looks like a warm front game tomorrow.
 
Looks like the 13Z outlook could shift things further west. The RUC is holding the moisture much further west than the NAM (Not Accurate Mostly) by 21Z, and moisture return across much of Oklahoma has been very impressive overnight, with the main body of the state socked in with low-mid 60s dewpoints. RUC has all of OK basically capped like yesterday, but I'll be watching the new runs this morning to see if that solution is modified a bit. With everyone's focus on the high risk area, S KS/OK could be a sleeper today.

For those of you chasing the bullet storms in MO/ILL...pick a target, and drive away from it about 30-50 miles. You need to find a good spot for viewing well ahead of the action and hope it puts on a show as it whizzes by. You get one shot with systems like these, then you're behind it the rest of the day. Stay safe, good luck, and please try to call in anything you see. Days like today (if things pan out as advertised) are when people need all the warning they can get.
 
I agree Shane. The RUC has the dryline in c OK/c KS at 21z. It has the low down to 993 by that same time and has the warm front hauling north(between 18-21z). Check out the winds behind the dryline too. Yikes. I wonder what, if any, affects this early morning convection in KS will have on the day. Probably none I guess as it races off to the nne north of the wf. I just hate seeing too much of that going on. I guess maybe I'm paranoid about anything screwing up the...day after having seen many high risk busts.

As for only getting one shot up to the north I think you can get more than that. If the drlyine is producing supercells and not this crazy line one can just drive due east and catch them as they come up from the sw. That looks like a hell of a dryline punch on the RUC though so who knows what will be the mode on that.

Part of me wants to move my target sw of St. Joe now, but I do not want to be too far west today. I also don't want to mess with picking options to cross the river. By the way, crossing ne into St. Joe is not the quickest option in the world. If you do so watch very closely for that exit to take the one segment east. I was watching closely and had the gps zoomed way in and I missed it the other day. One other thing, don't expect curve signs on all MO smaller paved roads. Some of those sharp peaks will have curves as you go down the other side. Don't need anyone at the bottom of Bob's hill.

Target just north of KC I guess. That will probably change in a few hours. Man is that dryline still way west on the RUC at 21z.
 
Seems local media here is split, as one station is saying the dryline will blast east and another is saying OKC might be added to the slight risk area later today. I guess it depends on which model you believe, and for my money the RUC has been the choice in this very young chase season. This is a repeat of yesterday for me, as I'll be watching the OK mesonet religiously throughout the morning to see what that dryline is gonna do. If it hangs around by 21Z as advertised, there might be hope down here yet.

As for the high risk target, H is right. You can keep up with storms if you can get a good road, but the window is still relatively narrow. Storms that root and deviate should slow some, but that's still probably 40-45mph. It's very difficult, but it can be done. Good luck!!!
 
0900 UTC RUC is very interesting, and gives me some more hope that the action may be a bit further west. On the other hand, the rapid approach of the 500 mb vortmax may justify a quick push of the dryline east between 2100 UTC and 0000 UTC across all of KS and OK, per the Eta. The RUC is a little bit SW of the Eta's position with the main energy in the 500 mb trough, so this is probably why it's holding things back a bit.
 
LOL I love it. First, I'll say that I'm very pleased that it looks like the dryline will be farther west this afternoon -- the 9z RUC run has the dryline along I35 in OK/KS/TX at 21z. I just awoke to a wondrous feelig (I sleep next to a window) -- humidity! Tds across OK are currently in the 60-65F region in the warm sector, and surface maps indicate Tds in the 67-68F range sitting in westecentral and southwestern LA, poisted to move northward/northwestward. If the 9z RUC run is to be believed, I think I'm more favored to nc OK and sc KS than N TX, as it shows relatively low CINH at the former, and substantial CINH remaining at the latter. In addition, most previous runs had winds veering a bit even ahead of the dryline north of the Red River area, which the 9z ruc no longer shows. I'm not sure exactly wher ethe dryline will be by 21z, since winds in sw/wc OK are veered a bit, telling me that any moisture out there will quickly mix out this morning as the dryline takes shape. Ah yes, the 21z RUC forecast initiates precip just east of i35 in southern ks as well.

EDIT: New 12z RUC out, and it looks like it shows a dryline bulge near Salina-Emporia area at 0z, with some other dryline disparity near the Red river as well. In fact, convectiion does develop just north of that Red-River / N TX dryline bulge that the RUC shows ( see http://68.226.77.253/models/RUC/CENTRAL_RU...S_CAPE_12HR.gif ). The 12z also continues to indicate convective initiation just east of I35 in sc KS, as well as initiation in sc and se OK by 0z. This trough looks like it may come out a bit deeper or less positively-tilted than I remember previous runs showing it to be. 12z RUC Shows the 993mb sfc low to be located between Salina and Hays KS at 0z. BTW, I realize I'm model-listing here, but I haven't had much time yet to get the interpretation machine working (it's 740am afterall). LOL.

EDIT 2: Geez, Check out St. Louis's AFD --> http://kamala.cod.edu/offs/KLSX/0603121246.fxus63.html ... Geez, it's like that discussion is to St. Louis as the Katrina doomsday statement was to the Slidell office.
 
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