06/07/05 TALK: N Plains

[Douglas Mitchell]

Figured this day warranted a TALK thread due to the SPC issuing a Day 2 MOD risk. Wind profile looks good over SE SD, good direction, decent speed and ridiculous instability. GFS and NAM both progging CAPE in excess of 6000 j/kg and LI's greater than -14 from Aberdeen to Sioux Falls. I know its too early to pick a target, but I think I'll be starting the day in Brookings, SD. Hope to see some of you out there.

 

[Justin Turcotte]

No suprise with the moderate risk as the NAM has been very consistent over the last few runs for this period. It has also been very consistent placing the the theta-e boundary/warm front in east-central to northeast SD. The 06z NAM places a -13 LI bullseye near Aberdeen by 18z. It fires convection in the 21-00z period. Attempting to find any null factors and there arn't many. An MCS might plow through the Dakotas/MN tonight and the airmass might need some recovery. So many great set-ups are blown by residual cloud in these parts. I'll be starting the day in Grand Forks for my usual bad luck luck shift on a higher threat day getting the MNDoT forecast out so atleast I'll be looking at data all day. I'll be flying south shortly after 2pm to get into a preliminary Redfield-Huron-Watertown-Brookings quad. This will take approximately three hours, putting me there shortly after 5pm. Hoping the cap holds things off until then. By far the best set-up for the Dakotas/MN this year and I don't want to miss it. Will see what the 12z runs offer shortly. Good luck to all NP chasers on this one.

 

[nickgrillo]

It still looks great in the latest run, and I am probably gonna still be headed for SE SD. Here is a AFD from Sioux Falls...

TUESDAY AFTERNOON INTO WEDNESDAY MORNING...ATTENTION THEN TURNS TO TUESDAY AFTERNOON WHICH MAY PROVE TO BE A LARGE SEVERE OUTBREAK WITH THE POTENTIAL FOR LONG LIVED SUPERCELLS.

 

[Brandon Clement]

I just got home last night from my second 3000+ mile four day chase.

With that said, Tuesday makes me want to say hmmm..... I'm very tempted to head out tonight and target somewhere in the vicinity of Mitchell, Sd. It sure is nice to see all this gulf moisture finally make it up into the Northern plains and very nice to see some consistent model runs. Now all we need is for the cap to play along. Good luck to all that chase, I think tomorrow will finally yield some large stovepipes and wedges as long as the cap holds till late afternoon/early evening. If I wasn't so exhausted I would be on my way already.

 

[Mikey Gribble]

I have been watching Tuesday for a while now. I would be excited if Saturday hadn't happened. The day is showing good potential though. I am leaving for South Dakota as soon as I get done packing. Right now I am looking at staying the night somewhere in SE to Scentral South Dakota. I have never chased South Dakota before. Does anyone know how good the terrain and road networks are. I was checking maps last night to get an idea of the roads and I saw that there are two huge lakes that run N/S in the target area that could be a serious problem on Tuesday.

 

[Ben Prusia]

I might be leaving early in the morning tomorrow for SD should 0Z model runs hold up on the situation. I have also never chased SD, let alone been in the state of SD before in my life so this will be completely new. I have heard from others that SD is pristine chase territory, but if I do leave early in the morning, I will be heading to Sioux Falls, targetting a Mitchell, SD to Brookings, SD area.

12Z model runs are favorable for an area of E SD, just the NAM has me wondering about cap strength.

 

[Jayson Prentice]

I am going to try and get an actual forecast up tonight after the model runs... I'm awaiting the SPC day 2 outlook as well, this mornings models were interesting to say the least. I think I will try to get out there, especially since it isn't going to be a terrible drive from my view. Only 2 hrs out of FSD... Now to my model thoughts.. lol

NAM was still on track with the low in central SD and extreme cape over areas of the northern plains. They did not like to develop precip until after 00z, which may be possible. But, the cap may also break earlier given it did not show much CINH. GFS was just screwy in my opinion.. Throughout their model run they would develop precip. and then just dissapate it in the next timeframe. It was looking a lot like convective feedback to me, which wouldn't be a surprise... I'm sure the local AFD and SPC will have something to say about it.

Overall I say this should turn out to be at least a decent chase day, FSD AFD states a possible significant severe weather outbreak for tomorrow. ABR didn't say more then 2 sentences about anything... To early for target area besides saying somewhere in eastern SD.

 

[Justin Turcotte]

I have never chased South Dakota before. Does anyone know how good the terrain and road networks are.

The road network is worthy of an "A" grade. County and farm roads every mile. A perfect grid system but there are numerous small lakes. I-29 runs through east SD for quick moving around. SD speed limits aregenerally 75 on the interstate and 65 on the side roads. Lack of population and chasers tends to keep the roads relatively free of traffic. You might see some slow moving tractors as the planting season is running late due to all the water around. The two lakes you mention are Big Stone and Traverse at the " camel hump" in western MInnesota. Defenitely of serious consideration when route planning. Terrain is worthy of a B+ grade. The area generally flat to rolling hills. Im extreme northeast SD, southeast ND, and portions of western MN, the terrain is as flat as a squirrel on the freeway. Not too many trees in this area except shlterbelts and riparian habitat.

The 12z runs are in and the NAM has changed a bit. Still fairly consistent but it throws in a peculiar mesoscale boundary in southern MN. I'm not ganna latch on to that solution just yet. The GFS and Canadian still favoring northeast SD.

 

[fplowman]

Originally posted by Ben Prusia
I might be leaving early in the morning tomorrow for SD should 0Z model runs hold up on the situation. I have also never chased SD, let alone been in the state of SD before in my life so this will be completely new. I have heard from others that SD is pristine chase territory, but if I do leave early in the morning, I will be heading to Sioux Falls, targetting a Mitchell, SD to Brookings, SD area.

12Z model runs are favorable for an area of E SD, just the NAM has me wondering about cap strength.

Keep an eye out for me i think Im going on this one Ben.. Im supposed to hook up with Ron Gravelle from Ontario Canada up there..

Fred

 

[Edward Ballou]

Chasing in SD is pretty nice imho. Even when we do have severe weather, there aren't that many chasers out. I've yet to see a caravan yet. In my little experience so far, it seems a lot of the good stuff drops south.

There is a little construction on I-29 just south of Sioux Falls so it's kind of a bottleneck there. But they've widened to 3 lanes on the north side.

Should be a fun day!

 

[Jayson Prentice]

Thanks for the construction update Edward...

Moderate risk by the SPC has elongated north/south and has moved more along the track of the low pressure system. Tornado threat was a little less mentioned in this text. Storms look to become more linear faster is what I get out of it for the most part... Still a decent chase day looking...

 

[Kurt Silvey]

Originally posted by Michael Gribble
... I have never chased South Dakota before. Does anyone know how good the terrain and road networks are. I was checking maps last night to get an idea of the roads and I saw that there are two huge lakes that run N/S in the target area that could be a serious problem on Tuesday.

The state is pretty much divided n – s by the Missouri River (large long lakes without many crossings, I think there are only 7 )The western half of the state would probably be considered unchaseable. The eastern half or more so the eastern 1/3 is excellent for chasing. It has a great road network and very flat. But I would definitely recommend staying east of the Missouri River.

Lack of population and chasers tends to keep the roads relatively free of traffic.

Could SD see its first chaser convergence?

 

[Mike Peregrine]

oh I've seen plenty of chasers up in SD in the past ... very nice views up there, and the roads are perfectly fine. Bigger question usually is getting across the river, particularly if stuff initiates in O'Neil or northern Nebraska ... that can be a trick. I'm sure tomorrow will definitely see its share as well ... looks like a strong possibility for significant severe at this point ... I'll be up. This week continues to show a lot of potential. Looking forward to seeing everyone up there -

Mo

 

[Karen Politte]

Well, I've been proved this year that my forecasting skills are below the par of most everyone else I know, it seems - but......

Is anybody worried about the possibility of unidirectional shear across large parts of the target area tomorrow?

I was wondering why the NAM does not show much in the way of backing winds ahead or northeast of that low that is progged by 00Z? Indeed, most progged wind directions from south-central NE to north-western IA and south-eastern SD are veered. :? Also - it seems to show winds in the northern half of SD out of the north - suggesting a cold front?

I wonder why SPC has the MOD so far north and east.......the CAPE values are ridiculous throughout most of NE. Also - is a cap of +10oC a bit much for the target area?

Where is everybody targeting??? Are many travelling for this event?

Just the thoughts of a raving madwoman......sitting in OUN all week. And I do mean sitting...... :roll:

KR

 

[JHadorn]

A 10C cap doesn't bother me too terribly much, although it's certainly something to take into consideration. It's when you get those +20C caps that I feel you can pretty much toss all hope unless you can manage to get some incredible moisture convergence to help erode it.

That being said: I can see what you're talking about.

Flow is pretty much southerly at the surface until about 0z when a 996 mb low sets in over western NE.

I was concerned about the 850 temps, but surface temps are forecasted to hit the +100F mark in NE which *might* overcome the cap (850 temp of 20 - 25C). Once we overcome that it's smooth sailing for any parcels because 700 temps are only 10C. 500 temps are ice cold so hail will be a concern.

I don't really see a problem in directional shear. 700 and 500 winds are generally southwest with surface winds being south - shifting southeast.

LI of -2 to -6 should be sufficient.

Helicity will be fantastic.

SBCAPE will be insane.

I am not a forecaster by any measure, however. All these numbers mean very little to me.