Tuesday, January 19, 2010

Severe Storms Possible Tomorrow

Most of East Texas is still under the threat of severe weather tomorrow afternoon and evening. By analysing the sounding data above, looks like the main threat tomorrow will be a large hail event with a few high wind reports. I can't rule out an isolated tornado but as of now, the greatest tornado threat appears to be to our southeast. The hodograph indicates 0-1kn shear 6 m/s or about 12 knots. We normally like to see 0-1km shear at or above 20 knots for tornado development. However, when you look at the hodograph for 0-6 km shear we see there is around 37 m/s or 71 knots of shear. More than enough for supercell development. So it looks as though we will see sustained rotation updrafts however, the low level vorticity needed for tornado development is lacking.

The above image is of the MLCAPE forecast for tomorrow afternoon. Notice that all of East Texas is in the light blue which indicates CAPE values between 1000 - 1500 J/kg. This is more than enough instability this time of the year. The atmosphere is not as deep as we would find during the spring months thanks to the lower temperatures in the mid levels of the atmosphere. This should lead to a few storms producing large hail, maybe as large as golfballs.

The final image above shows the dewpoints, in the low 60s for most of East Texas, and streamlines, or surface wind direction. Models are hinting at a meso low developing near Dallas late tomorrow. If this low is deepens surface winds will back more out of the southeast and this would increase the tornado threat. So the next 36 hours does have the potential to produce severe weather but, at this time it does not look like a repeat of December 23rd 2009.

No comments: