Scroll down for Bill Murray’s posts on highway conditions, accidents, etc. Many bridges are iced over.
This is now a classic ice storm setup for central Alabama. We have a shallow layer of very cold air at the surface, with north winds bringing in a steady supply of cold, dry air. Above 3,000 feet, winds are out of the south, with the warm moist air overrunning the cold air near the surface. Over most of central Alabama, it is all falling as freezing rain now, with temperatures around 30 degrees. Icicles are hanging off objects, and any elevated surfaces (decks, bridges, etc.) have ice accumulating on them now, as the rain freezes on impact. Where the air is colder over NE Alabama, snow is falling.
Lots of rain is moving in from Mississippi now, and it will rain most of the night. Temperatures will not fall anymore, as the warm raindrops (at 33-34) fall and slowly bring the temperature up. Freezing itself releases some heat too. BHM has already risen from 28 to 30 degrees. So, temperatures will very slowly rise tonight. The big question is how soon it gets above 32. As long as we stay at 30, 31, or 32, ice continues to accumulate, making roads even worse, and possibly causing some power outages. The computer models completely blew this one from the beginning, so we’re not relying much on anything they say right now. The 6 pm balloon data from NWS Calera will be critical in determining just how warm or cold it is aloft, and how long we may stay below freezing.
Some places, especially in NW Alabama (NW of the Warrior River), may stay below freezing until tomorrow morning sometime, and have 1/2″ of ice. Here in BHM, best guess right now is that temperatures will rise above freezing between midnight and 6 am, but it will take a while for the icy bridges to melt, so travel in the morning even in BHM may be dangerous. And, if the balloon data shows colder air, BHM could stay below freezing into tomorrow morning.
Bottom line is that no travel should take place tonight on north and central Alabama roads…once you’re home, stay there. You might want to turn your heat up a little in case the power goes off. As for tomorrow morning’s rush hour…we think BHM will be improving by then, but we’re not sure.
I’ll have another complete analysis after the balloon data comes in, around 730 or 800.
