Wednesday, February 29, 2012

Update on another potential severe weather system on Friday

After a day like today, with a borderline moderate risk setup and Tornado Watch that ends up busting pretty bad, it would be understandable to head into the next event with a little skepticism.  However, this is what meteorologists do - mess one up, then get back up and charge full-steam into the next! So here we go!

Since most of our efforts the past few days have been concentrated on today's events, we haven't talked too much about Friday. That would be the weatherman's version of the old sports cliche about "overlooking the next opponent." With today behind us now, it's time to look ahead. Despite talking publicly mostly about today, we have also kept a close eye on Friday and models are in pretty decent agreement with the latter portion of the event - the cold frontal passage and the weather associated with it.  What they absolutely do NOT agree on is the early morning hours and we'll start there.

In the wake of today's cold front, humidity has plummeted as Gulf moisture was shoved south. However, this will be short-lived as a warm front ahead of Friday's system surges back north Thursday night, bringing that warm moist air back to the Mid-South. A couple of normally reliable models (GFS, ECMWF) indicate that rain and thunderstorms will break out in the pre-dawn hours Friday morning around this warm front, with some possibly containing hail and a threat of strong wind. The other model we use a great deal (NAM) is the one that performed the best leading up to today's system and it says "no dice" on Friday morning.  The Storm Prediction Center and NWS-Memphis go with the former theory and we'll try it  again as well! SPC places the metro in a Slight Risk for large hail and strong wind with some storms early Friday.

We'll then see a break in the precip in the wake of the retreating warm front and prior to the arrival of the cold front, which should move into the metro in the early evening hours. The break will be a chance for the atmosphere to A) energize on abundant Gulf moisture flowing north on gusty wind and B) likely destabilize with some sunshine and temps warming into the mid to upper 70s. All models indicate widespread convection firing ahead of the cold front late Friday afternoon into Friday night.  The big question is - like today - does this happen to our west (putting us in line for severe storms) or to our east (missing the metro entirely)?  It'll be close.  For now, we plan for the worst and hope for the best. A Slight Risk is also in place for Friday afternoon and evening with the primary threat being damaging wind and isolated tornadoes. I would say the highest risk is east of the metro, particularly NE MS, north AL, and middle TN ,where the tornado threat may be a little higher as well.  The MWN Storm Center has maps showing the details. The good news is that once this system moves through Friday night, we'll be left with DRY conditions (and mild) for several days, including a nice looking weekend!

Expect an update again tomorrow. The full MWN Forecast can be found here.

----
For weather information for Memphis and the Mid-South, where and when you need it, visit MemphisWeather.net on the web, m.memphisweather.net on your mobile phone, download our iPhone or Android apps, or visit us on Facebook or Twitter.

No comments: