The Tuesday afternoon Weather Xtreme Video is available in the player below, and on iTunes:
Read J.B.’s post from this morning about the cold air and the expected weather conditions in some cities to the west. This is going to be a very ugly visit from “ole man winter” here in late fall. Might even make the “global warming” crowd a little nervous.
THE ALABAMA STORY: There have been a few blips on the radar this afternoon, and we will mention the risk of widely scattered showers tonight and tomorrow, but the big rain event won’t get here until Thursday night. The very mild weather continues; I am watching our SKYCAM down at Demopolis right now… 76 degrees there on the historic White Bluffs of the Tombigbee River. Not bad for a late November day; that is 87 degrees warmer than Cutbank, Montana, where they have -11 at mid-afternoon with a wind chill index of -32.
WATCHING THE FRONT: A wave of low pressure is forecast to move along the Arctic front from near Dallas to Little Rock to Indianapolis and on to Detroit on Thursday; snow and ice is likely to the northwest of the track; strong to severe storms will be possible southeast of that track. Some 6 to 10 inch snow amounts should be found somewhere in that region on the cold air side of the storm, causing major travel issues and headaches for people who live there. Cities impacted by this major winter storm include Tulsa, St. Louis, Chicago, and Cleveland.
Down here in the warm sector, SPC has most of the state in a severe weather risk for Thursday night. The 12Z models continue to show excellent dynamics for strong to severe storms, but marginal thermodynamics. Here are some parameters from the 12Z run of the WRF/NAM for Birmingham Thursday night:
Surface based CAPE: 79 j/kg
0 to 3 km helicity: 235
850 mb wind speed: 44 knots
500 mb wind speed: 73 knots
200 mb wind speed: 119 knots
A strong short wave will approach our state Thursday night with a negative tilt and excellent wind fields, but surface based instability is very, very limited. Should those CAPE values rise to levels over 1,000, look out.
The main window for showers and storms will be from around 6:00 p.m. Thursday through 6:00 a.m. Friday; and I think we can narrow that down even more and suggest the best chance of any strong to severe storms will come from about midnight Thursday night through 6:00 Friday morning. Rain totals of 1/2 inch are likely, with isolated totals to one inch.
A COOL CHANGE FRIDAY: Still no real change in our thinking on Friday’s weather; the rain and storms will end early in the day, and temperatures will go the wrong way. We will begin in the 50s during the morning hours, dropping through the 40s; reaching the upper 30s by evening. The cold air will be very shallow, only about 2,000 feet deep. Temperatures will drop below freezing by early Saturday morning.
THE WEEKEND: The weather will be cool and dry Saturday and Sunday; the latest 12Z model runs keep the air too dry for any rain with the upper trough Sunday and Sunday night.
NEXT WEEK: Upper air winds finally allow deeper cold air to drop into Alabama Monday; looks like highs will drop into the 40s here. The Tennessee Valley might have a hard time getting out of the 30s Monday; we have to remember there should be a good snow cover just northwest of the state, so the cold air really won’t modify much. Looks like the coldest morning will come early Tuesday, with the mercury dropping well down into the 20s.
LONG RANGE: Still looks like a potential snow threat for areas north of I-40 around December 7 (north of a line from Memphis to Nashville), with just rain down here in Alabama. And, way out in voodoo land the GFS paints a severe weather look around December 13-14. But, lots of water will go under the bridge before we get there.
I sure enjoyed being at Cullman East Elementary School this morning; I spoke with the 6th graders about the great science of meteorology and they were a great audience. Be sure and look for them on the KIDCAM today on ABC 33/40 News at 5:00.
The next Weather Xtreme video will be posted bright and early tomorrow morning by 7:00 a.m…
