Wednesday, April 17 Severe Weather Outbreak Forecast

Just a quick update as far as the potential for severe weather tomorrow (Wednesday).

Though models still disagree with the frontal position by tomorrow afternoon/evening, they all suggest severe weather occurring in the vicinity of the warm/stationary front, as well as inside the warm sector.  GFS model is the most aggressive model, lifting the warm front as far north as central and northern KS. NAM, on the other hand, is the opposite, lifting the front right at or just south of Oklahoma City.  The EURO splits the difference, lifting the warm front closer to the OK/KS border.  This will be a very important feature in where the severe weather occurs tomorrow.

There is still the question on how late night/early morning convection will affect the setup for surface-based supercells in the warm sector, if any form at all. As of writing this (00z Wednesday), latest models all have showers and/or thunderstorms occurring in northwest TX and northern OK. However, as of right now, there is not a single echo return found in the region. This doesn’t mean they won’t form at all tonight, just something to consider when talking about the forecast models. The RAP model eventually does form showers and storms in extreme northwest OK and southwest KS by 06z or 1am Wednesday.

Existing storms and cloud cover could alter surface and mid-level perturbations for tomorrow afternoon.  Regardless whether there is early morning convection in Oklahoma or Kansas, conditions will still favor severe weather for the area, depending on location of the warm/stationary front.  Dewpoints will be in the mid to upper 60s, bulk shear will range from 40-60 knots in places, little or no cap inversion, and major diffluence aloft will be occurring by tomorrow afternoon.  There will also be a dryline that will be propagating eastward throughout the day, setting up in western OK and western-north TX by mid-afternoon.  All of these ingredients will aid in the development of supercells as early as 1 pm tomorrow, though storm initiation timing is still questionable.

Tornadoes are the biggest threat with any storm that goes severe, though I don’t think it will be a huge outbreak, unless it’s the worst case scenario where conditions are set up exactly right.  However, I wouldn’t be surprise if one or two tornadoes were strong (EF-3 or greater), either.  Best chance of tornadoes will be in southwest OK and western-north TX (near Wichita Falls).  Aside from the tornado threat, that’s conditional, hail and wind will not be conditional.  Large hail and very gusty winds WILL be likely with any storm that forms.  Hail may get as big as baseballs or softballs with some storms. Winds may gust in excess of 70-75 mph.  These two threats alone will make these storms very dangerous.

Overall, still many questions about location and timing of storm initiation.  With situations like this, we may not know until a few hours before the event. However, I am very confident that severe storms will occur tomorrow, maybe not tornadic storms, but severe storms that might cause hail and wind damage to property. IF tornadic storms do occur, they have the potential to be strong, long track tornadoes.

About Brian

University of Oklahoma graduate with a degree in Meteorology. Follow me on Twitter: @WeatherInformer
This entry was posted in Weather and tagged , . Bookmark the permalink.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s