04/19/05 FCST: Central Plains/Southern Plains

[nickgrillo]

A strong, >40kt SW LLJ continues to advect substantial boundary layer moisture east of the dryline from IA southward into TX... The NAM has surface-based CAPE progged >4500j/kg in southeast Nebraska, with very strong low-level shear (>300m2/s2 0-3km SRH). I'd call for supercells with very large hail (given the extreme instability and low wet bulb heights) along with a few isolated tornadoes.

Latest outlook graphic:
http://midwestchase.com/wxforecasts/04_19_05-4.gif

..Nick..

 

[Tom Dulong]

Perhaps chasers in the high plains should think more about northeast CO late this afternoon. Cool front has backed into this area a little more strongly than earlier forecast, so surface dewpoints in the upper 40s to lower 50s are advecting toward the Denver area. The associated frontal cloud band is thin and won't be much of a hinderance to reacing convective temperature. 12Z RUC has the best forecasts sounding for severe at 20/00Z along the front from Denver east-southeastward. CAPES are forecasted to be about 2000 j/kg with helicity 200 m**2/sec**2...these are good values for this area. Also, upper flow will be approching 50 kts which is stronger than points farther east. My play would be along and just south of I70 from Denver to
Limon...scattered large hailers and a few tornadoes.

 

[Glen Romine]

early target LBF with plans to change that after further review.

Just gave another look around - and think I'll venture a bit further west. happy to see the low-level clouds thinning out - and convection starting to fire in the northern front range. Cold front continues to sit just east of Sidney, with the low retrograding a bit back toward the west from it's earlier position. Expected ne cell motion even for a supercell in this area has me favoring where the boundary is more ne-sw oriented. Very strong capping inversion according to the RUC analyses seems to bound se edge to around McCook - with west bounded by cf. Retreating warm front north of low wrapping back around to near Ovid, CO, which could be the best area for CI on the next few hours. Think I'll drift my virtual chase crew west to Ogalalla - and have them plan to play the boundary intersecting through there as convection comes up from the sw later today.

Glen

 

[Tony Laubach]

This is becoming a class Douglas County/Elbert County setup for areas near the Front Range... Denver's latest HWO uses some pretty strong wording for areas south and southeast of the Denver Metro area. A weak cold front is resting against the front range and I would image storms will kick off from there. Terrain features of the Palmer Divide are also gonna aid with development as winds are in an upslope direction. Storms interacting with the frontal boundry will likely become severe with hail probably a very good bet across areas of the Metro area itself. Brief landspout tornadoes are also very likely in areas east of I-25. I'm gonna take my 4 hour break and shoot towards Parker to play for a bit.. storms expected to fire about 2ish oughta be enough time to play before having to go to my other job!