2016-03-07 EVENT: NE, KS, OK, TX

[Royce Sheibal]

I don't even think I can forecast this event correctly for the northern half, as the models are so polarized. NAM says nothing north of the OK/KS border until 06Z, and HRRR agrees. Meanwhile GFS and RAP bring in some convection as far north at NE/SD border between 00Z and 06Z. Surface temps in Omaha are nearing 70F with DP's nearly 60. The forecast models all show a heavy capping inversion aloft, but most of that is due to overcast that is being forecast, but not actually happening in most areas.

We've got a nice Q-field setting up in SE Neb and also out near North Platte with patches of sun in between. There has to be a dry slot hiding just to our SW that will kill off a chance of storms this afternoon, because if there isn't then the SPC's new forecast revision will make them look silly, again. Some of the models are even forecasting the surface dryline to retrograde in the KS/NE area, which could make for some ENH SRH. In the meantime, we're going to break records in Omaha for highs, with 81 a likely forecast...and it feels and smells like rain out there.

My prediction: we get dry slotted (because we always do) until 06Z when the better lapse rates push into the area and make some isolated supercells, LCL's are forecast by the models to be nice and low, meanwhile the offices are putting them up really high. I guess the big question is how to forecast early March in a cold state. Agree with the low LCL's of the models and keep the tor chance, or forecast like it's September and predict high-based wind-gusters?

Target Area if you're feeling REALLY lucky: Columbus Nebraska at Sundown, pushing toward Omaha at 06Z. I cherry picked a few soundings and between 00Z and 06Z I found a handful that still get the "TORNADO" Risk hazard. Despite the human forecasts nay-saying today all around, the machines often see things we can't and I typically side with them.

 

[James Gustina]

Seems like the dews in the NW corner of the state are finally mixing a bit but the I-40 corridor and south is still holding steady even with the increased solar radiation. The clearing at the very least is encouraging but the specter of that inversion is still hanging around.

 

[Jeff Duda]

Somewhat encouraged by the thermodynamic environment in SW OK and into NW TX at the moment. Clouds are clearing more than I expected, and temperatures are creeping into the 70s. There's even a few obs (Hollis/Altus/Tipton etc.) showing dewpoints 62+. Lapse rates also appear to be a little higher than previous forecasts led on. The result is that there's a pretty healthy amount of CAPE building along the dryline from W OK and through W TX. I'd like to see a little more backing of the winds before I got real confident on initiation in OK today, but there are some good signs showing up.

I'm also keeping an eye on the weak convection that has developed in C TX. The models have been progging this pretty hardcore, with the HRRRX trying to blow it up into a damn squall line by the afternoon. As of now, some earlier HRRR runs have overpredicted this convection, but other CAMs like the 12Z 4 km NAM suggested robust initiation would wait until mid-afternoon. If we can make it to the 20-21Z time frame and still not have significant convection developing in the warm sector across C/N TX and S OK, I'll be even more prone to think the DL may go in OK.