Severe Weather Discussion for May 9-10, 2015.
– Severe thunderstorms are likely this morning across much of Oklahoma and again this afternoon across the western 1/3rd. The threat this morning is large hail to quarter size. This afternoon the primary threats are large hail to baseball size, flash flooding, and winds to 75mph. A few tornadoes are possible, especially in far western Oklahoma.
– A few severe thunderstorms are possible on Sunday, currently not expecting much more than large hail and some damaging winds. Flooding rainfall is the greatest threat.
Forecast Changes: Today has been modulated significantly downward re tornado threat, which now appears limited in space and time.
Numerous runs of storms since Tuesday have greatly stabilized the atmosphere in terms of available moisture, cool temperatures and interrupted low level moisture. The issue for today is how much atmospheric recovery can occur and how far north. Current thinking is that west-central and southwest Oklahoma will have the best chance to recover. Even though NW OK will have direct influence of the upper system, not sure this will be enough to overcome the overturned atmosphere. Additionally, effective outflow boundary in Texas will likely move to near I-40 by afternoon, per HRRRR resulting in elevated storms in Kansas. HRRR also has low 60s dewpoints and mid 60s temperatures in KS and parts of NW OK.
4km NAM should arrive shortly, but I anticipate little change from the 12z HRRR. SPC has dropped the moderate risk and this looks good. The enhanced risk is well placed covering much of western Oklahoma for large hail. The 10% tornado threat was kept but may be dropped or moved on the 16:30z update.
Since this event does not reach the medium-end range, this will be the last discussion.
None – tomorrow will be a slight risk.
Still thinking of going today, but currently on the fence.by