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As expected, we are enjoying a fine Friday with ample sunshine and temperatures in the mid 60s in most communities. Dewpoints are very low; in fact the dewpoint in Birmingham is only 14 at 2:00. Needless to say, we will see a radical airmass change during the next 36 hours.
MAJOR STORM SYSTEM FORMING: SPC maintains a moderate severe weather risk for this afternoon and tonight from near Childress and Wichita Falls, Texas northward into southern Kansas. A deep surface low will form this evening over the Texas panhandle, and will move northeast to a point north of Kansas City by late tomorrow night. In the warm sector of the storm, widespread severe weather is likely, and the action will shift eastward during the day tomorrow.
The SPC Day 2 Outlook hasn’t changed much; a moderate risk of severe weather tomorrow along and west of I-55 in Mississippi, into much of Arkansas and Louisiana. A slight risk extends eastward into Alabama for tomorrow night and the pre-dawn hours Sunday.
We still believe the greatest risk of severe thunderstorms in Alabama will come from about 9:00 tomorrow night through 6:00 a.m. Sunday. The 12Z model runs have come in with better instability, and accordingly severe weather parameters look more impressive. Still, the pattern suggests the primary severe weather risk will come from a squall line with widespread, damaging straight line winds. Models still show 850 mb winds (around 5,000 feet) of over 65 knots over much of North and Central Alabama in the 12:00 midnight to 3:00 a.m. time frame. Even away from thunderstorm winds could gust to over 45 mph at the surface.
The potential is there for a widespread wind damage event, possibly a serial derecho type situation.
With higher 0 to 3 km helicity values showing up (over 1,000 m2/s2!) and the better instability values, we sure can’t rule out a few isolated tornadoes. Bottom line is that a significant chance of severe weather is ahead late tomorrow night into early Sunday, and every Alabamian needs to be in a position to hear severe weather warnings.
The sky will become partly sunny on Sunday as the storms move on to the east; we figure the line of storms will move out of East Alabama by 9:00 a.m.
NEXT WEEK: The first half of the week looks dry with seasonal temperatures. The 12Z run of the GFS is back on board with a major upper trough moving through here at the end of the week, with strong storms possible followed by a sharp change to colder air for the following weekend. That 12Z run paints a very interesting scenario, in fact; it hints at a major surface low forming in the northeast Gulf of Mexico around Saturday March 3, which might even bring a snow threat to parts of the southern U.S. Of course, that is just one run and the setup will change a number of times. We need to get this weekend’s system out of the way and then we can focus on that one.
STORM ALERT 2007: Don’t forget our annual severe weather awareness tour will be next Tuesday (not Thursday!) at the Bessemer Civic Center at 7:00; the doors open at 5:00. Bring the whole family; this is our only show in the Birmingham metro area this year, and the last chance to see it.
WEATHER PARTY: Get the latest related news on our sister site, weatherparty.com. Be sure and register and you can submit links and vote on them to determine what is published on the main page. Lots of read over there right now.
Needless to say, we will be keeping a close eye on the situation over the weekend and we will have frequent updates on the blog… Stay tuned!
