29 May 2013 – Virtual Chase – Hobart(KHBR), OK

A MOD RISK day in Oklahoma (but I’m working in Chicago), so we’ll chase virtually.

SPC’s tornado outlook has a big sausage-shaped area (hatched!) along western Oklahoma, but where do we target within a 96,000 square mile blob?

20130529-1300Z-SPC-day1probotlk_1300_torn

INITIAL TARGET: Hobart, OK

 

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VIRTUAL BASE: Salina, KS

RATIONALE: Looking over RAP and NAM (WRF-NMM) models, I see 30-40kt 500mb winds over southwest Oklahoma.

20130529-1200Z-RAP-uc12hr_500_wnd

Checking this vs. the Dew point, moisture convergence, and CAPE/CINH, the area from the southwest corner of Oklahoma to Weatherford, OK looks like where I’d predict a good chance to strong tornadoes. Using the NAM model, I see precipitation broken out for my target area during the 18-21Z area.

20130529-1200Z-NAM(WRF-NMM)-eta21hr_sfc_prcp

0840CDT: If I started from a virtual base city of Salina, KS, I’d be at the waffle maker at someplace like the Days Inn Salina South reviewing these models.
My departure would be at about 9:30 a.m., with an estimated arrival at Elk City, OK of about 3 pm (a 5.5 hours drive via I-35S and I40W).

0853CDT: METAR at Salina: KSLN 291353Z 19015G27KT 10SM BKN020 23/19 A2968 RMK AO2 PK WND 15031/1307 SLP038 T02280189=
Translation: 73 deGF and mostly cloudy. A brisk S to SSE wind at 17mph with gusts to 31mph. 1004mb pressure. Dewpoint is 66F already. “Air you can wear.”

13:34CDT: In the virtual world, I’m stopped to gas up for the afternoon near El Reno,OK, make a bathroom stop, and re-assess conditions. I regret having to bypass Moore, for a look from I-35, but I’ve headed west on I-40. I can’t observe the sky in the real world, but the surface map, visible satellite, and webcams give me an idea what I’d think if I were there: continue west for now, then re-assess at 14:30 or so.Temperature at El Reno is 77F with a *screaming* 68F dew point, scattered clouds, and a healthy 27mph wind.  It seems that moisture is getting carried WAY north of my position. But, I also need to be patient!

Maybe I’ll stop at Sayre, and consider going north, as storms are already popping west and north of there. A huge TOR watch area — the red shaded area in the map below— covers much of western Oklahoma and continues north into Kansas (where a really long line of chasers are heading west on US54, apparently try to catch the storm straddling the Clark-Comanche county line, south of Dodge City).

20130529-1343CDT-KFRD-radar-CR-ET

Now the hard part: do I abandon my original target or hope the southern storms produce. Choices, choices, choices!

14:00CDT – After watch radar and checking SBCAPE, I decide to abandon my target. Tall, ferocious storms are building on the OK-KS line, head up through Watonga on US270W, hoping there are still storms to chase around 16:00CDT.  Supercell composite is 12 for the area.  Hopefully, I can make good time without getting a ticket. *Looks both ways, crosses fingers*

16:00CDT: Look like storm to the south is picking up. Dropping south to Seiling,OK

1630CDT: Storms east and west. Will stick with the westerm storms, aiming for the ‘tail end Charlie’. Head south on US183.
Problem: Not many road options until Clinton!

1730CDT: I see (from GRLevel3) that Vic Gensini from CoD is on the storm by Memphis, TX.  I’m going to let it come to me. It’s adjacent to the new ‘tail end Charlie’ to its southwest. *crosses fingers*

20130529-1725CDT-KAMA-CR-ET

[NOTE: Real-world issues have interrupted. I may have to break off this virtual chase.]

RESULT: A work-related crisis took me away from this virtual chase, but I would have reached sever storms in any case.
There were several tornado reports nearby, but odds are that I would NOT have seen them.  As the map below indicates, most of the significant tornado action occurs north and outside of the originally predicted sausage-shaped area of high tornado probability.

20130529-preliminary-storm-reports

 

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