Tuesday, January 29, 2013Special Morning Update - January 29 Severe Weather Event
By Andrew at 6:27 AM
Today is the big day. We are seeing the Storm Prediction Center maintain a Moderate Risk call for severe weather through much of Arkansas into extreme southern Missouri, extreme northern Louisiana and a very small portion of northwest Mississippi. A slight risk exists across the Plains, Midwest and Gulf Coast.
On a side note, I am maintaining my Storm Action Day call and will not upgrade to a Critical Storm Action Day unless the environment becomes more favorable for such a call.
A tornado watch has already been issued for much of Oklahoma and a few counties in northern Texas. This comes as a result of thunderstorms firing in Oklahoma, extending back through Texas. I anticipate these storms to continue strengthening along the nocturnal lower level jet stream, already feeding on the tight pressure gradient known as a dryline, which does go right up against these thunderstorms. By the looks of them, the tornado threat is highest right now, as the storms are not yet linear and are more individualized. The threat is lower in southeast Kansas and northern Texas, where there are no watches yet. Oklahoma City could be hit by some individual storm cells in coming hours as this not-yet-linear complex of cells moves east.
My main concern at the moment is extreme damaging winds. The above forecast shows wind speeds for 9 PM Central time, with wind speeds just a few thousand feet above the ground. My worry is that these winds will be provoked to move down towards the surface as the storms begin to take on a more linear shape and evolve into a squall line. When this does happen, the risk of tornadoes drops considerably and the threat for damaging winds skyrockets. Looking at the map, we would be seeing lower level winds above 72 knots in parts of the Moderate Risk area, something that could easily provoke extreme damaging winds.
I will provide updates as often as possible throughout the day, and will do another afternoon update later on in the day.
Heed all National Weather Service watches and warnings, and be prepared to seek shelter if you are in the path of these storms.
Andrew [link to theweathercentre.blogspot.de