Late night update

Starting to move a little bit away from models to looking out the window tonight.

Warm front near Cullman tonight and moving north…dewpoint in BHM is 65, in Nashville it’s 34.  High clouds have moved in ahead of the main system, keeping temperatures from dropping much tonight (it’s still 70 in BHM right now), and with high clouds tonight (that stop outgoing radiational cooling), temperatures won’t drop more than 3 or 4 degrees.   Some stations are reporting a broken deck of clouds at 4,000 feet or so also.

One of the things that may determine how severe the storms  get tomorrow is how much low cloud cover hangs on.  If we get lots of sunshine and temperatures rise up into the mid 70s, the air over Alabama will become very unstable by 10 or 11 am, and supercell storms could fire by late morning in the moderately high shear environment (helicity 200-300).  If these storms fire, we could be dealing with tornado warnings before lunch.  If we can keep low clouds going all day, the threat will be lessened some.  That is a tough call.

The main threat time is tomorrow afternoon (again the warmer it gets, the more supercell storms and possibly tornadoes we’ll see), and then the evening, when the cold front comes through, likely with a squall line producing damaging winds and isolated tornadoes.

See below for safety tips from James and me.

Category: Severe Weather