Chase Case 7

[Jeff Duda]

18Z Update

18Z update​

Note the times on some of the products. They might not all be at exactly 18Z.

Surface:
Southern Plains
Central Plains
Northern Plains
Upper Midwest
Midwest/Mid-Mississippi valley

Satellite:
National (error: national satellite feed is down and will not return for the duration of this chase)
Southern Plains
Central Plains
Northern Plains
Mississippi valley

Radar:
National

Wind profiler:
Lower troposphere
Upper troposphere

Special 18Z soundings were launched due to the prospects for severe weather at the following locations:
Amarillo, TX
Dodge City, KS
North Platte, NE
Midland-Odessa, TX
Norman, OK
Rapid City, SD

Those soundings, coupled with the RUC analysis, result in the following SPC mesoanalysis graphics:
300 mb upper air
500 mb upper air
700 mb upper air
850 mb upper air
Effective SRH and effective inflow base depth
Mid-level lapse rate
LCL heights
SBCAPE/CIN

Current wayfaring map: http://www.wayfaring.com/maps/show/60773

Expect updates to begin coming more frequently, starting with the 19Z update later this evening. Hopefully this timing will allow all that wish to join the chase the chance to before things get heated. Good luck to all!

 

[Damon Scott Hynes]

I'm heading toward Ponca City, OK.

 

[Michael Riedl]

Sorry I joined this way late, I am going to leave ICT and head out to Pratt, Kansas. Centrally Located, I think there May be a play in Central KS and WRN KS, gives me some access to both. Coming close on decision time though. Gives me enough Opportunity to bolt to Northern OK if necessary. The cloud cover is quite Discouraging for most of Central KS.

 

[David Wolfson]

Heading up to Oakley, KS, for 19Z. Storms will be flying toward the northeast at 40+ and I'd rather be a little north than the alternative. As expected a screaming dry punch is forming in southeast CO.

 

[JHardy]

My mind is screaming head north! But I am staying put here in Odessa Tx. I think there is a dry line up by Tucumcari NM to the north. But It would take me hours to blast up that way so I wil sit and watch down here.

 

[Verne Carlson]

Heading into the deeper moisture and line of towers building to my southeast near Dodge City, KS

 

[Patrick Martin]

I now recognize the date. I am out. Good luck to all those still on this chase.

 

[Tim Purington]

Still in Dodge City, KS. I see no reason to move. I think I'll go over to Sonic and grab a couple bacon cheeseburgers.

 

[L.B. LaForce]

I think im gonna punch north a little to Liberal, KS

 

[Bob Hartig]

I seem to find myself near Johnson City east of US 27. Looking at the 18z info, I think this is as far north as I want to go. I see the 700mb impulse heading this way out of NM, and I think I want to be closer to it than farther from it. But where I'm at may be a bit too far west. Better moisture and surface winds to my east. I like the DDC sounding. Think I'm going to park it for now in Sublette, KS.

 

[Jeff Duda]

Intermediate update

Intermediate update
*The current time in the chase is approximately 1830Z*​

MESOSCALE DISCUSSION
NWS STORM PREDICTION CENTER NORMAN OK

AREAS AFFECTED...TX PNHDL...SOUTH PLAINS

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

LATEST RUC SUGGESTS DESTABILIZATION IS BECOMING MAXIMIZED WITH
INHIBITION WEAKENING EAST OF SURFACE DRY LINE...FROM THE TEXAS SOUTH PLAINS THROUGH THE TEXAS PANHANDLE. THIS APPEARS TO BE WHERE LOW-LEVEL MOISTENING/ISENTROPIC ASCENT IS STRONGEST...ALONG 30-40 KT SOUTHERLY LOW-LEVEL JET. ALTHOUGH HIGH CLOUDINESS HAS SOMEWHAT RESTRICTED SURFACE HEATING TO THIS POINT...OBJECTIVE ANALYSIS INDICATES THAT MIXED LAYER CAPE IS ALREADY ON THE ORDER OF 1500-2OOO J/KG. WITH FURTHER INSOLATION...THIS MAY REACH 2000-3000 J/KG BY LATE AFTERNOON.

A WEAK IMPULSE MAY BE PROGRESSING THROUGH THE DEEP LAYER CYCLONIC
SOUTHERLY FLOW REGIME ACROSS THE SOUTHERN HIGH PLAINS AT THE PRESENT TIME. IN THE WAKE OF THIS FEATURE...SURFACE DRY LINE IS EXPECTED TO MIX EASTWARD ACROSS PARTS OF THE TEXAS PANHANDLE AND SOUTH PLAINS. WITH MOST SIGNIFICANT UPPER IMPULSE WELL UPSTREAM...IT IS UNCERTAIN WHEN/IF PACIFIC FRONT WILL OVERTAKE THE DRY LINE. HOWEVER...MUCH OF MODEL GUIDANCE HAS INDICATED THE LIKELIHOOD OF THE INITIATION OF AT LEAST ISOLATED CONVECTIVE DEVELOPMENT TO THE EAST OF DRY LINE...BENEATH DIFLUENT/DIVERGENT UPPER FLOW...POSSIBLY AS EARLY AS 20-21Z.

IF THIS OCCURS...SUPERCELLS ARE EXPECTED TO RAPIDLY FORM IN ENVIRONMENT WITH SIZABLE...CLOCKWISE CURVED HODOGRAPHS...BENEATH MODERATELY STRONG AND STRENGTHENING SOUTHERLY HIGH LEVEL JET. ADDITIONAL STORMS ARE EXPECTED TO ENSUE INTO/THROUGH EARLY EVENING ASSOCIATED WITH FORCING ALONG DRY LINE...ACCOMPANIED BY RISK FOR VERY LARGE HAIL/DAMAGING WIND GUSTS...AND ISOLATED TORNADOES.

Mesoscale discussion #1 graphic

 

[Brian Stertz]

Sitting in Colby KS wondering about 18z ticker...got some nice moisture cu flying north. Surface low deepening over Colorado....should be in prime spot nearby when things finally begin to set from flood mode.

 

[JHardy]

I think I am a bit south so I am moving up to O'Donnell Tx. Just a short 1 hour drive north. Might have to zoom up north as the day goes.

 

[Jason Boggs]

I'm still home in Amarillo, and it's too late to go very far north, so I'm going southeast to Guthrie, TX.

 

[Karla Dorman]

Since I'm a first time chaser, don't know what the heck I'm doing. LOL But gut's telling me to head on up to Pampa, TX. So, on my way ...