Convective Addiction

3/27/10 FCST: Potential Cold Core Event

Posted on 25. Mar, 2010 by Jesse in Forecasts

Are you tired of popping anti-SDS pharmaceutical products? If so, this weekend offers a potentially paltry cold core event in SE KS and Western MO. The 00z GFS and NAM, as well as the 12z ECMWF are fairly synchronous in propelling an upper level cold core low eastward along the KS/OK border region from 06z SAT to 00z SUN. The models do diverge on exact placement and strength of the system at 00z Sunday; notwithstanding, they are similar in the relative spoor of the system. Ahead of this upper level system, surface dew points in the low to mid-50s arrive in far SW Missouri by 21z Saturday per the NAM; the GFS remains more cautious, suppressing the best surface dew points well to the ESE by 00z Saturday.

The 500 mb temperatures are progged to approach -23 C (-5 C at 700 mb) atop the aforementioned surface dew points, which may reach the low 50s across far SW MO and SE KS. The NAM is more bullish on the 0-3 km lapse rates across the region, with the GFS suppressing them much further to the south as the system advances eastward. CAPE values could reach as high as 750 J/Kg across the region by per the 00z NAM.   One potential fly in the ointment remains a persistent area of light rain associated with the moisture influx ahead of this system. Both the GFS and the NAM have been indicating this area of rain across far SE KS and extreme N. OK, which could hinder the amount of insolation across the areas where the best potential for cold core convection would reside, otherwise absent any low cloud cover or surface convection.  However, should adequate solar insolation materialize, conjoined with steep lapse rates, any storms that fire in the region ahead of the surface low near localized boundary interactions would have the potential to produce severe weather.

J.L. Risley

SREF 2010 0327/2100z

0-6KM Bulk Shear - 2010 0327/21z

2m Dew point > or = 50 degrees / 20100328 - 00z

SREF 700-500 mb lapse rate >= 7.0 / 2010327 at 21z