Jeff Snyder
EF5
There may be two possible plays for Monday, at least according to the 12z GFS And 00z EMCWF from last evening... The first would be the more typical warm-sector play primarily along and E of I35 in the southern plains, as a strong mid-level low moves into OK (12z GFS) or KS (00z ECMWF). As is common for this early in the season, it is likely that low-level moisture will be quite marginal. The second area, which is the area that has my attention at this time, is a possible "cold-core" play... Looking at the 12z GFS, this setup screams "cold-core low-topped supercell" to me. For example, using the 12z GFS output, 500mb temps may well run colder than -25C as the mid-level cold pocket moves into Oklahoma and maybe far southern Kansas. Underneath and to the northeast of the the mid-level cold pocket, I'm seeing very backed low-level flow (E or ESE) with dewpoints in the mid-upper 40s across south-central Kansas (early afternoon) and southeastern KS and adjacent parts of northcentral/northeastern OK (mid-late afternoon) to the northeast of a <996 mb low. The specifics of whether we'll see enough insolation to create steep low-level lapse rates (which will then affect the 0-3km CAPE) can't really be known this far out (hey, it's the 126-132 hr forecast from the GFS!), but pattern recognition (e.g. March, strong closed mid-level low with associated cold pocket plowing into the southern Plains, strong surface low with very backed low-level flow to its northeast, very marginal dewpoints for "typical" warm-sector convection, etc.) is leading me to watch carefully the OK/KS border area for a potential "500 mb cold-core, closed low" low-topped supercell setup.
I should note that I don't have access to the higher-resolution ECMWF forecasts, other than the very limited selection of low-res products on CoD's site. The latest ECMWF that I can see (again, off CoD) has the mid-level low and surface low farther north (primarily in KS), which would push the threat for low-topped supercells in the "500mb closed, cold-core low" conceptual model to the north accordingly. It's hard to get excited about Tds in the 40s, but that's all it takes in these types of setups (I vividly recall watching a tornado in Dewey Co in March 2006 with Tds in the low 40s and heavy snow falling ~30 miles to the NW).
EDIT: Thanks to Buddy Bradley for pointing out that I somehow forgot about the whole "new year" thing. As such, the year has been changed from 09 to 10. Doh!![Wink ;) ;)](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
I should note that I don't have access to the higher-resolution ECMWF forecasts, other than the very limited selection of low-res products on CoD's site. The latest ECMWF that I can see (again, off CoD) has the mid-level low and surface low farther north (primarily in KS), which would push the threat for low-topped supercells in the "500mb closed, cold-core low" conceptual model to the north accordingly. It's hard to get excited about Tds in the 40s, but that's all it takes in these types of setups (I vividly recall watching a tornado in Dewey Co in March 2006 with Tds in the low 40s and heavy snow falling ~30 miles to the NW).
EDIT: Thanks to Buddy Bradley for pointing out that I somehow forgot about the whole "new year" thing. As such, the year has been changed from 09 to 10. Doh!
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