Chase 2011 - Day 19 Discussion

[Paul Sherman]

Better chance for Tornadoes today with a 5% Risk in Western Oklahoma and the Panhandles, SE Colorado also has another day of Upslope play.

Long drive tomorrow so off to bed as it is 130am

Paul S

[nsrobins]

Classic cap or bust day today. Initiation very dependant on some degree of surface heating which in turn requires clear skies.

Should heating occur then vectors look favourable for tornadic supercells but it will be a watch teh skies sort of day as far as target choice goes.

Off the sleeve I might look at the Guymon area - probably right or just east of the DL - and see if it clears for long enough.

[nsrobins]

I'm beginning to think the CS OK area, just west of teh I35, may be an option in terms of better CAPE and CIN drop-out with maximum daytime heating. It's a trade-off though as the better directional shear is in the NE of OK (maybe not as far as Guymon though) but will the crappy stuff clear. Haven't seen the latest vis sat images but basically a lot hinges on seeing the sun today. <BR><BR>Thursday shaping up to be a more signifiant day than today.

Edited May 18, 2011 by nsrobins

[TornadoJo]

I had a look at the charts for this earlier today.

I initially went for weatherford (Western OK) but looking at the models im not sure if I want to be a bit further south.

Still - Weatherford looks like a good starting point - just hope it's not a cap bust.

Other option is central Kansas but I have reservations about there as, although there is little/no Cap there is no CAPE.

So sticking to Weatherford for now - unless I missed something?

[ian cameron]

Well things run in 3's. Now Paul Shermans car has a shredded tyre, we are doing a Formula 1 style change west of Colby on I-70, at least it happened earlier in the day and not in chase mode.

That's all 3 done now.

[Coast]

Have the team considered a back up vehicle?

[NL]

Nice Cu fields showing up on the latest satellite image. Will it wont it, question mark speaks for itself..!!

[UkStormChaser]

Have the team considered a back up vehicle?

ROFL

Edited May 18, 2011 by UkStormChaser

[UkStormChaser]

Making my way towards target area of Geary, OK. Looking good for possible supercells and isolated tornadoes that will fire along I40 and move east towards Oklahoma City.

[NL]

MD released from SPC regarding severe potential watch.

MCD - 18/2045Z

ACUS11 KWNS 181944 SWOMCD SPC MCD 181944 OKZ000-TXZ000-182045- MESOSCALE DISCUSSION 0804 NWS STORM PREDICTION CENTER NORMAN OK 0244 PM CDT WED MAY 18 2011 AREAS AFFECTED...WRN/CNTRL OK...PORTIONS OF N TX CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE VALID 181944Z - 182045Z THE POTENTIAL FOR CONVECTIVE INITIATION APPEARS TO BE INCREASING THIS AFTERNOON ACROSS WRN OK AND PORTIONS OF N TX...ALTHOUGH SOME UNCERTAINTY STILL REMAINS. THE ENVIRONMENT WILL BE FAVORABLE FOR ISOLATED SUPERCELLS CAPABLE OF PRODUCING VERY LARGE HAIL AND POSSIBLY TORNADOES. THE AREA IS BEING MONITORED FOR A POSSIBLE WW. STRONG DIABATIC HEATING ACROSS WRN OK HAS RESULTED IN AN EWD ADVANCEMENT OF A SFC DRYLINE...POSITIONED FROM 40 SSW SPS TO FSI TO 40 NE CSM /PER 19Z SUBJECTIVE ANALYSIS/. THIS FEATURE IS ATTENDANT TO A DEEPENING SFC LOW...AND A DIFFUSE BAROCLINIC ZONE/WARM FRONT PROTRUDING ESE ACROSS CNTRL AND SERN OK. THERE IS SOME UNCERTAINTY REGARDING CONVECTIVE INITIATION AS RECENT SFC OBSERVATIONS HAVE INDICATED WINDS IN THE POST-DRYLINE ENVIRONMENT HAVE BACKED TOWARDS THE S /LIMITING LOW-LEVEL CONVERGENCE/. THIS MAY BE OFFSET BY AN AREA OF IMPLIED ASCENT THAT APPEARS TO BE SPREADING EWD OUT OF THE SRN HIGH PLAINS...WHERE A BROAD SWATH OF CIRRUS HAS DEVELOPED IN RECENT VISIBLE SATELLITE/WATER VAPOR IMAGES. AS THIS APPROACHES WRN OK AND NW TX...WEAKENING CINH AND INCREASING MID-LEVEL ASCENT SHOULD LEAD TO A MORE FAVORABLE ENVIRONMENT FOR CONVECTIVE INITIATION THIS AFTERNOON. RICH BOUNDARY LAYER MOISTURE AHEAD OF THE DRYLINE /LOWER-MID 60S SFC DEW POINTS/ ALONG WITH STEEP MIDLEVEL LAPSE RATES IN EXCESS OF 7 DEG C PER KM HAS YIELDED MLCAPE VALUES OF 1500-2000 J/KG...WHICH WILL SUPPORT A THREAT FOR VERY LARGE HAIL. ADDITIONALLY...ENHANCED LOW-LEVEL WIND SHEAR RESULTING FROM BACKED FLOW /PARTICULARLY WITH NWD EXTENT/...ALONG WITH A FAVORED DISCRETE CONVECTIVE MODE DUE TO A SIGNIFICANT ORTHOGONAL COMPONENT OF THE EFFECTIVE SHEAR VECTOR RELATIVE TO THE DRYLINE...SHOULD SUPPORT A THREAT FOR TORNADOES IF LONG-LIVED SUPERCELLS CAN DEVELOP. HOWEVER...CLOUD COVER ACROSS CNTRL OK HAS LIMITED HEATING/INSTABILITY PRIMARILY E OF I-35...WITH SOME QUESTION REGARDING MAINTENANCE OF THUNDERSTORMS MOVING E OFF THE DRYLINE.

[Dorsetbred]

MD released from SPC regarding severe potential watch.

MCD - 18/2045Z

ACUS11 KWNS 181944 SWOMCD SPC MCD 181944 OKZ000-TXZ000-182045- MESOSCALE DISCUSSION 0804 NWS STORM PREDICTION CENTER NORMAN OK 0244 PM CDT WED MAY 18 2011 AREAS AFFECTED...WRN/CNTRL OK...PORTIONS OF N TX CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE VALID 181944Z - 182045Z THE POTENTIAL FOR CONVECTIVE INITIATION APPEARS TO BE INCREASING THIS AFTERNOON ACROSS WRN OK AND PORTIONS OF N TX...ALTHOUGH SOME UNCERTAINTY STILL REMAINS. THE ENVIRONMENT WILL BE FAVORABLE FOR ISOLATED SUPERCELLS CAPABLE OF PRODUCING VERY LARGE HAIL AND POSSIBLY TORNADOES. THE AREA IS BEING MONITORED FOR A POSSIBLE WW. STRONG DIABATIC HEATING ACROSS WRN OK HAS RESULTED IN AN EWD ADVANCEMENT OF A SFC DRYLINE...POSITIONED FROM 40 SSW SPS TO FSI TO 40 NE CSM /PER 19Z SUBJECTIVE ANALYSIS/. THIS FEATURE IS ATTENDANT TO A DEEPENING SFC LOW...AND A DIFFUSE BAROCLINIC ZONE/WARM FRONT PROTRUDING ESE ACROSS CNTRL AND SERN OK. THERE IS SOME UNCERTAINTY REGARDING CONVECTIVE INITIATION AS RECENT SFC OBSERVATIONS HAVE INDICATED WINDS IN THE POST-DRYLINE ENVIRONMENT HAVE BACKED TOWARDS THE S /LIMITING LOW-LEVEL CONVERGENCE/. THIS MAY BE OFFSET BY AN AREA OF IMPLIED ASCENT THAT APPEARS TO BE SPREADING EWD OUT OF THE SRN HIGH PLAINS...WHERE A BROAD SWATH OF CIRRUS HAS DEVELOPED IN RECENT VISIBLE SATELLITE/WATER VAPOR IMAGES. AS THIS APPROACHES WRN OK AND NW TX...WEAKENING CINH AND INCREASING MID-LEVEL ASCENT SHOULD LEAD TO A MORE FAVORABLE ENVIRONMENT FOR CONVECTIVE INITIATION THIS AFTERNOON. RICH BOUNDARY LAYER MOISTURE AHEAD OF THE DRYLINE /LOWER-MID 60S SFC DEW POINTS/ ALONG WITH STEEP MIDLEVEL LAPSE RATES IN EXCESS OF 7 DEG C PER KM HAS YIELDED MLCAPE VALUES OF 1500-2000 J/KG...WHICH WILL SUPPORT A THREAT FOR VERY LARGE HAIL. ADDITIONALLY...ENHANCED LOW-LEVEL WIND SHEAR RESULTING FROM BACKED FLOW /PARTICULARLY WITH NWD EXTENT/...ALONG WITH A FAVORED DISCRETE CONVECTIVE MODE DUE TO A SIGNIFICANT ORTHOGONAL COMPONENT OF THE EFFECTIVE SHEAR VECTOR RELATIVE TO THE DRYLINE...SHOULD SUPPORT A THREAT FOR TORNADOES IF LONG-LIVED SUPERCELLS CAN DEVELOP. HOWEVER...CLOUD COVER ACROSS CNTRL OK HAS LIMITED HEATING/INSTABILITY PRIMARILY E OF I-35...WITH SOME QUESTION REGARDING MAINTENANCE OF THUNDERSTORMS MOVING E OFF THE DRYLINE.

Go you lucky barstewards GO!

Edited May 18, 2011 by Dorsetbred

[Roger J Smith]

Would suggest Buffalo OK to Woodward OK as most likely area for severe storm development ... dry line has overshot upper support and cool air mass is entrenched over KS, so eventual triple point likely to be held south of KS-OK border ... large ACC field on satellite imagery moving northeast across TX panhandle ... don't think the team is very far from this suggested target now anyway, last time I looked at GPS they were near Garden City KS. Some severe cells could reach southern tier of KS counties but feel that western OK the most likely risk zone.

[TornadoJo]

well I'm happy in weatherford for now. in the md area (just I think) n good road options too. if a cell popped up a bit further north as suggested I could get there pretty quick. if I was actually in america of course. . .

I-hop franchise in the uk? yes please! ( the storms go without saying!)

http://www.spc.noaa.gov/products/watch/ww0306.html - yay

Edited May 18, 2011 by TornadoJo

[ian cameron]

Hi All we have the first precipatation of the day from the cell 8 miles from us

[Gorky]

I'm in Orienta at the moment. Cell to me WSW seems to be trying to root. Best so far after a number of failed attempts. I'm in a good position if this does go severe. You can follow my icon on Spotter network for those who want..

[Gorky]

/Fell apart like the others.... I notice the HRRR is now no longer showing any initiation after doing so for most for the day

[Nick F]

I'm liking the look of the Watonga to Woodward area of NW/N-central Oklahoma for any storms that get going ... and it looks like they are trying to near the dryline/warm front triple point where there will be enhanced lift and backing surface winds. Kinematics and wind shear are looking good in this area on the hourly mesoscale analysis. Dew points hitting nearly 60F across NW/N central Oklahoma now:

2000-2500 j/kg SBCAPE overlayed by strong 0-3km shear, looking good for any supercell in this area to become a tornado producer:

Only obstacle now seems to be cap inhibiting parcels from rising high, need those temps to get higher... which may risk a bust today.

[ian cameron]

Hi Nathen we are around 30 miles to your west watching the same thing

[Roger J Smith]

Hey, I see there's a Sherman Oklahoma, not quite as big as Sherman Texas. Team must be pretty close to there now, it's between Woodward and Orienta.

[Nick F]

Hi Nathen we are around 30 miles to your west watching the same thing

Hey Ian, can you point the camera down a bit? All I see is sky B)

[Paul Sherman]

Strange old day in Oklahoma, Cap bust in the end but we were in good company with TVN, Jim Leonard and a Canadian Tv crew that did a 10 minute interview with us, I would like to think i held my composure pretty well with chickens and shower caps trying to put me and the News anchor off, a few pictures and even Nathan turned up for the cap bust party

Paul S