Chase Case #15

[Kurt Hulst]

Since 15z I have headed over to Okaley, KS As of now I am going to sit tight right here i have good road systems in every direction. I am losing my confidence in this northern Target but its still early I wish I could see a 20z update or something near there.

 

[Matt Gingery]

I've got a couple extra seats here to get us to a target!

Yeah, forget about the corvette. That is what I am talkin about. That is how to storm chase, in a chopper. . .Sweet set up man!!!!!

 

[Bob Hartig]

Save a seat for me. This garbage truck I'm driving just ain't cuttin' it.

 

[Patrick Martin]

18z: The cirrus shield has broken up a bit since 15z, but that, along with limited moisture concerns me, although winds are nicely backed. If the cirrus shield can continue to errode should get some decent heating. I've committed to the northern play so have to hope for the best. Going to adjust further west to Oakley, KS which will provide some good options in any direction.

 

[Andrea Griffa]

Still hanging on down here in Bird City on my tractor with all the crew! I'm tired of watching the sky of 18Z We need some action,Paul

 

[Paul Austin]

Sorry for the delay, folks. I've been a bit tied up. I will start giving hourly updates (that is, 19z, 20z, etc.) a couple per day. I have decided against the live chase for this event. I have enough update material, but I don't think I can commit enough time and attention to do it justice. Perhaps in a future case. Okay, so the next update will be up shortly.

 

[Paul Austin]

18z Supplemental Info

Still around 18z, when the following mesoscale discussions are released by SPC:

MD #5

MESOSCALE DISCUSSION 5[FONT=&quot]
[/FONT]NWS STORM PREDICTION CENTER NORMAN OK[FONT=&quot]
[/FONT]1229 PM CDT[FONT=&quot]
[/FONT]AREAS AFFECTED...SERN OK...NERN TX...NRN LA...NRN MS AND SWRN AR[FONT=&quot]
[/FONT]CONCERNING...SEVERE THUNDERSTORM POTENTIAL [FONT=&quot]

[/FONT]VALID 1729Z - 2030Z[FONT=&quot]
[/FONT]STORMS ARE EXPECTED TO DEVELOP ALONG/N OF WARM FRONT IN ARKLATEX[FONT=&quot]
[/FONT]REGION THIS AFTERNOON AS WELL AS FARTHER E INTO SRN/CNTRL MS. TIMING[FONT=&quot]
[/FONT]OF INITIATION IS STILL UNCERTAIN...BUT ONCE STORMS[FONT=&quot]
[/FONT]DEVELOP...SUPERCELLS WILL BE LIKELY. LARGE HAIL AND ISOLATED[FONT=&quot]
[/FONT]DAMAGING WIND APPEAR TO BE THE MAIN THREATS. HOWEVER...AN ISOLATED[FONT=&quot]
[/FONT]TORNADO OR TWO WILL ALSO BE POSSIBLE.[FONT=&quot]

[/FONT]SURFACE DATA SHOW A WARM FRONT FROM SRN MS WNWWD THROUGH NRN LA INTO[FONT=&quot]
[/FONT]NERN AND N CNTRL TX. RICH LOW LEVEL MOISTURE...SURFACE HEATING AND[FONT=&quot]
[/FONT]STEEP LAPSE RATES ARE SUPPORTING DESTABILIZATION ALONG AND S OF THE[FONT=&quot]
[/FONT]BOUNDARY WITH MLCAPES ALREADY FROM 2000 TO 2500 J/KG. LATEST VISIBLE[FONT=&quot]
[/FONT]DATA SHOW CUMULUS CONTINUES TO INCREASE IN THE VICINITY OF THE[FONT=&quot]
[/FONT]BOUNDARY. THE ATMOSPHERE STILL APPEARS CAPPED NEAR THE BOUNDARY...[FONT=&quot]
[/FONT]AND THIS IN CONJUNCTION WITH UPPER RIDGING MAY DELAY SURFACE BASED[FONT=&quot]
[/FONT]INITIATION ANOTHER 1-2 HOURS. LOW LEVEL JET SHOULD STRENGTHEN OVER[FONT=&quot]
[/FONT]THE SRN PLAINS INTO THE AFTERNOON AS SURFACE RIDGE AXIS SHIFTS EWD[FONT=&quot]
[/FONT]AND EXIT REGION OF UPPER JET MOVES INTO THE HIGH PLAINS. THIS WILL[FONT=&quot]
[/FONT]SUPPORT INCREASING LIFT ALONG/N OF WARM FRONT. RADAR IMAGERY ALREADY[FONT=&quot]
[/FONT]SHOWS ISOLATED ELEVATED CELLS TRYING TO DEVELOP N OF THE FRONT OVER[FONT=&quot]
[/FONT]CNTRL OK. OTHER STORMS WILL LIKELY DEVELOP FARTHER S CLOSER TO THE[FONT=&quot]
[/FONT]SURFACE FRONT AS CAP WEAKENS THIS AFTERNOON. BACKED LOW LEVEL FLOW N[FONT=&quot]
[/FONT]OF THE WARM FRONT UNDERNEATH MODERATE WLY MID LEVEL FLOW IS[FONT=&quot]
[/FONT]SUPPORTING SUFFICIENT DEEP SHEAR FOR SUPERCELLS. LOW LEVEL FLOW IS[FONT=&quot]
[/FONT]CURRENTLY RATHER WEAK..RESULTING IN RELATIVELY SMALL[FONT=&quot]
[/FONT]HODOGRAPHS...AND THIS MAY INITIALLY SERVE AS LIMITING FACTOR FOR[FONT=&quot]
[/FONT]TORNADOES. HOWEVER...STRENGTHENING LOW LEVEL JET LATER THIS[FONT=&quot]
[/FONT]AFTERNOON SHOULD SUPPORT BIGGER HODOGRAPHS OVER THE SRN PLAINS WHICH[FONT=&quot]
[/FONT]WOULD INCREASE THE THREAT OF ISOLATED TORNADOES.[FONT=&quot]

[/FONT]

MD #6

MESOSCALE DISCUSSION 6[FONT=&quot]
[/FONT]NWS STORM PREDICTION CENTER NORMAN OK[FONT=&quot]
[/FONT]1248 PM CDT[FONT=&quot]
[/FONT]AREAS AFFECTED...ERN WY...SWRN SD...NERN CO...AND THE NEB PANHANDLE[FONT=&quot]
[/FONT]CONCERNING...SEVERE THUNDERSTORM POTENTIAL [FONT=&quot]

[/FONT]VALID 1748Z - 2015Z[FONT=&quot]
[/FONT]THUNDERSTORM DEVELOPMENT IS ANTICIPATED ACROSS THE CENTRAL HIGH[FONT=&quot]
[/FONT]PLAINS REGION DURING THE NEXT 1-3 HOURS...PARTICULARLY ACROSS ERN[FONT=&quot]
[/FONT]WY. THREAT OF SEVERE STORMS INCLUDING A FEW SUPERCELLS MAY REQUIRE[FONT=&quot]
[/FONT]WW IN THE REGION LATER THIS AFTERNOON.[FONT=&quot]

[/FONT]WATER VAPOR IMAGERY AT 1730Z SUGGESTS A REGION OF UPPER-LEVEL[FONT=&quot]
[/FONT]DIVERGENCE SPREADING NEWD FROM THE CENTRAL ROCKIES TOWARD THE[FONT=&quot]
[/FONT]DISCUSSION AREA. ASSOCIATED SURFACE PRESSURE FALLS ON THE ORDER OF[FONT=&quot]
[/FONT]2-3 MB/2 HR CONTINUE ACROSS ERN CO...ERN WY...AND THE NEB PANHANDLE.[FONT=&quot]
[/FONT]RAPID CLEARING OCCURRED LATE THIS MORNING ACROSS NERN CO...ERN[FONT=&quot]
[/FONT]WY...THE NEB PANHANDLE SETTING THE STAGE FOR DESTABILIZATION AND[FONT=&quot]
[/FONT]STEEPENING LOW-LEVEL LAPSE RATES ACROSS THE REGION THIS AFTERNOON.[FONT=&quot]
[/FONT]VISIBLE IMAGERY ALSO SHOWS A CONSIDERABLE AMOUNT OF CUMULUS[FONT=&quot]
[/FONT]DEVELOPMENT ACROSS THE MTNS OF CENTRAL WY.[FONT=&quot]

[/FONT]AS FORCING FOR ASCENT EMERGES INTO THE CENTRAL HIGH PLAINS AREA THIS[FONT=&quot]
[/FONT]AFTERNOON...IN CONJUNCTION WITH CONTINUED SURFACE[FONT=&quot]
[/FONT]HEATING...ISOLATED/SCATTERED THUNDERSTORMS ARE EXPECTED FROM NERN WY[FONT=&quot]
[/FONT]SWD INTO NERN CO. IF PRESSURE FALLS CAN REMAIN FOCUSED ALONG THE[FONT=&quot]
[/FONT]FRONT RANGE...A SSELY BOUNDARY LAYER FLOW WILL CONTINUE TO ADVECT[FONT=&quot]
[/FONT]MOISTURE /DEWPOINTS INTO THE LOW 50S/ INTO THE REGION ALLOWING FOR[FONT=&quot]
[/FONT]100MB MLCAPE VALUES OF 1000-1500 J/KG AND AN ASSOCIATED THREAT OF[FONT=&quot]
[/FONT]SEVERE STORMS. DEEP LAYER SHEAR /SFC-6KM/ AROUND 40KT SHOULD[FONT=&quot]
[/FONT]INCREASE THIS AFTERNOON...AND SHOULD BE SUFFICIENT FOR ROTATING[FONT=&quot]
[/FONT]STORMS. HAIL AND ISOLATED/LOCALIZED DAMAGING WINDS WILL BE THE[FONT=&quot]
[/FONT]PRIMARY THREAT. HOWEVER...WHERE LOW-LEVEL FLOW REMAINS BACKED THIS[FONT=&quot]
[/FONT]AFTERNOON...TORNADOES ARE ALSO POSSIBLE.[FONT=&quot]


19z Update will be issued later this afternoon and 20z tonight...

[/FONT]

 

[Verne Carlson]

Based on the second MD, moving from Bird City, KS to Julesburg, CO

 

[Paul Austin]

19z Update

19Z Observations:


Visible Satellite Imagery:
Northern Plains
Central Plains
Mid-Mississippi Valley

Radar Imagery:
Northern Plains
Central Plains
Southern Plains
Middle Mississippi Valley
Lower Mississippi Valley

EDIT: Added upon request:

Surface Observations:
19z Central Plains Sfc

Chase Positioning Map

 

[Andrea Griffa]

I 'm joining up with Verne and heading to Julesbourg,Ne.

 

[Michael O'Keeffe]

My dad and I are sitting on US 277 SW of Wichita Falls watching a classic cu field with towers trying to break the cap. Going to monitor the skies closely and probably just relax and throw a frisbee or something.

 

[Bob Hartig]

I'll toss in my hat with the Julesburg crowd. Looking forward to seeing some surface obs. Meanwhile, playing to the north, and to the east part of the MD, makes backing winds a good bet. Plus, Verne's got a copter, so even though I'm driving a garbage truck, I can always ditch that for a quick shuttle service when the storms start firing.

 

[Paul Austin]

I'll toss in my hat with the Julesburg crowd. Looking forward to seeing some surface obs....

Here ya go:

19z Central Plains Sfc

 

[Verne Carlson]

Liking the building convection off to our northwest from Julesburg, CO - might move a little west on I-80 after throwing the frisbee around a bit with everyone!

 

[Jason Branz]

Agree that NErn CO is looking better with time. But since that's too far for me, I'm going to head south from GAG to CDS and hope something pops along the convergence line over the eastern TX panhandle.