MarionCountyMessenger.com Staff Meteorologist Robert Frye explains…
Forecast guidance indicates cyclogenesis will occur over the southern plain states on Monday along a quasi stationary frontal boundary draped across the southern plains into the Mid-Miss River Valley. Aloft, strong 300mb jet axis is also projected to set up across Oklahoma, Texas, and Arkansas. At the same time a shortwave will progress eastward and take on a more negative tilt. The stationary front south of the low is expect to SLOWLY move eastward as a cold front and a warm front will push northward through the Midwestern states in response to a (very slightly) more progressive mid-level flow. The initial low is projected to eject northeastward along the slow moving frontal boundary through late Monday and Tuesday. Secondary cyclogenesis is currently being advertised by both global and mesoscale models just east of the Ozarks (again) along the boundary. This secondary low is expected to move northeastward through Tuesday Night and Wednesday.
Severe Storms are expected to develop Tuesday Afternoon over the Mid-Miss River Valley. Storms are expected to move SW to NE along the slow moving cold front upstream. However, due to strong WAA associated with a 40-50kt LLJ, isolated convection is possible. Isolated severe storms are possible Tuesday Evening; however, instability and any severe threat will decrease during the overnight hours.
As the front finally approaches the region, numerous showers and tstorms will be possible Wednesday Afternoon and Evening. Given cape of 1500-2000 j/kg and 0-1km SRH of 200-250 m2s2, severe thunderstorms will be possible as the front nears. Currently, a squall with damaging straight-line winds (especially in bowing segments) looks to be the main severe weather threat at this time. However, due to moderate wind shear (0-3km SRH of 300-350 m2s2), we certainly can’t rule out a tornado threat. There remains a good bit of uncertainty as models differ on timing and strength of the secondary low that is expected to form Tuesday Afternoon.
Tuesday Evening/Overnight- Isolated showers and thunderstorms are possible. An isolated severe storm or two will be possible early.
Wednesday- Numerous showers and thunderstorms expected (especially in the afternoon and evening hours). Some storms may be severe.
Meteorologist: Robert Frye
Updated: 4/24/2011 at 11:08 PM