Severe Weather Discussion for May 9 – 10, 2015.
– Active and potentially significant severe weather event on Saturday. Tornadoes, large hail, damaging winds and flash flooding are all expected.
– Severe thunderstorms are possible across central and eastern Oklahoma on Sunday.
Extremely complex forecast for Saturday, which seems to be the trend this year. Early morning convection has been a problem in recent events and appears tomorrow is no exception. 00z NAM 4km/HRRR both show widespread showers and thunderstorms developing in west Texas and moving east, reaching western OK at 7am. These storms then progress eastward across the state. I have doubts if the storms will be as intense as indicated by the models given the robust activity in Texas/Oklahoma this evening. I do think the atmosphere needs more time to reset, but we’ll see. Of interest is that lack of storm intensity in Texas, compared to last night. Since the early morning storms are likely being driven by a shortwave trof, there should be NVA behind this feature. The 4km NAM indeed shows the Texas panhandle/western OK clearing out by 1pm. As such, intense daytime heating should initiate in wake of this shortwave trof/convection.
Models continue to advertise an intense 500mb closed low will impinge upon the dryline, which surges east by 2pm into the eastern TX panhandle. Dewpoints in the upper 60s/low 70s in strong diurnal heating regime will result in widespread SBCAPE of 2500 J/Kg and near 4500 J/Kg in SW OK. Despite the fact that skies are clear west of I-35 by 4pm, with temperatures in the mid 70s, this model does not generate convection. I believe this is a model error and we’ll probably need to see what 12z runs show before getting a better idea. Either way, I believe that the 4km NAM, backed up the the HRRR point to a significant severe weather event on Saturday with the potential for long-lived supercells.
We’re looking to leave 12:30pm to 1pm or so. Target area is Watonga. This is the best blind of 500mb closed low influences and instability.
Persons across Oklahoma are urged to remain weather aware tomorrow. If I thought tomorrow was more clear cut, I’d go higher with the high risk probs. At this juncture I think a high risk is possible from Clinton northward into the Dodge City area.
Risk area for any part of OK (valid: 05/09 Day 1, Day 2):
Slight: 100%, 100%
Enhanced: 100%, 50%
Moderate: 100%, 0%
High: 25%, 0%
Level 2 – Heading out Saturday, Watonga is the spot..by