To see the pictures that viewers sent in about the light to moderate snow in North Alabama, go here. A classic example of the models just being too warm! The best advice for a forecaster in events like THIS are… don’t forecast snow until you see the first flake fall, then you’ll always be right.
http://web.waaytv.com/galleries.php?id=10
Forecast Update: 1:30pm
What computer models all agreed to as rain has begun as snow in NW and NC Alabama, showing that colder than expected air has arrived in the middle levels of the atmosphere. Haleyville dropped to 30 degrees when it started, and it looks like other areas will cool rapidly to near or slightly above freezing. This may mean light snow accumulations on grassy areas and elevated roads thru the evening hours, when warmer weather is expected to move in and change any precipitation into rain.
Travel difficulties may extend Valley-ward as the storm precipitation moves in, especially under heavier ’squalls’, where it can pile up a bit faster than it can melt. This situation will be a changing one until the precip establishes it’s type for the next 3 hours
BOTTOMLINE:
NWS Issues Winter Weather Advisory for elevations above 1500 feet for exactly this forecast until 4am. Precip should be completely over by 3am.
Rain for all. Possible Snow/Sleet MIX late evening to early overnight for Franklin, Moore, Marion, TN, and Elevated Madison, Jackson, Marshall, DeKalb amd Cherokee, AL, only accumulations on decks cartops, limbs and power lines. Travel impact MINIMAL. Any location E of I-65 could see changeover or mix briefly change to snow for brief time, with no accumulations. Therefore, Storm Force 31 story remains the same, for mountain residents adding a better chance for light ice accumulations. Best News: Roadways are sufficiently WARM to avoid icing on mountain roads. ‘Valley’ roads, 100% chances of remaining fine. ‘Valley’ bridges, 80% chance of remaining fine. Expect closings delays in Mountain counties schools by the early AM. Rest of Valley will be fine. Can’t speak to their decisions. May close in Huntsville and Decatur because of the threat for severe weather in March.
Background:
Rains moving from the NE, with cold air sinking in from the NE & E (called cold air damming). As cooling air and rising precip meet, rain begins to be frozen aloft in the clouds, and falls down. Where temps are above freezing, rain is mixed with sleet. Where temps are at or below freezing, rain freezes on contact with trees, power lines, bridges, etc, called freezing rain. If atmosphere is cold enough higher up in the atmosphere, snow forms and falls.
Forecast:
This afternoon: Rains keep moving NE, first up into Blount, Etowah Cherokee, and into Marshall and Dekalb Counties by late afternoon. The cold air damming starts south first (with the air heading AROUND the mountains first, then over later) and rain mixed with sleet starts in these counties. No accumulations or driving problems.
This Evening: Rain spreads areawide, and remains ALL rain west of I-65, and most of Madison, Morgan, and Lincoln Counties, with some rain mixing with sleet and perhaps highest elevation freezing on lines and limbs between 7pm and 10pm. Roadways stay fine. Brief changeovers to light non-accumulating snow are possible I-65 East.
Overnight: All of the TN Valley sees rain changeover, but on highest elevations, light accumulations of freezing rain are possible, esp on limbs, lines, decks, car tops. Certain problem bridges may get patchy ice on mountain tops, but roads stay water. Temps stay above freezing areawide, except for mountain tops to near 30.
Tomorrow: Rains end. Temps Rise.
Stay tuned to Storm Force 31 on waaytv.com and WAAY-31 for updates and details.
Brad Huffines, Chief Meteorolgist / Storm Force 31
