Tuesday Night, March 3, 2015
Chief Meteorologist Jason Simpson

Temperatures drop like a rock, freezing rain likely by Thursday morning

Winter Storm Watch in effect

Tuesday’s high of 66ºF (as of 10 PM) in Huntsville was the warmest reading since Valentine’s Day, and if we manage to crack 70ºF on Wednesday before an Arctic front arrives, it will be the first time in 2015. Normally, we’ve had 70ºF at least once by February 1st. The latest 70-degree day on record was March 19, 1969; if we don’t get 70 on Wednesday, it could be after the middle of the month before we get there.

Temperatures drop like a rock Wednesday evening: from the upper 60s at 4 PM to the 30s by 10 PM. That fast push of cold air catches up with a good round of rain, and together they will set us up for a winter storm early Thursday morning.

Winter storm potential: The greatest threat of significant ice, power outages, and hazardous travel looks to be in Tennessee, northern Mississippi, and extreme northwestern Alabama. That’s where temperatures drop fastest and precipitation will still be heavy enough to create some potentially serious problems.

This will be different than winter weather events earlier this season. For one, the ground is relatively warm now. Four-inch soil temperatures are in the 40s and 50s right now; the pavement temperature in Downtown Huntsville at 2 PM was 47-48ºF. Travel impacts will be minimal if there is no “frozen” precipitation (sleet or snow). Freezing rain is rain that freezes on impact with a surface that is colder than 32ºF; that’s what we expect the majority of this precipitation to be.

Temperatures start dropping Wednesday afternoon and evening; we will plunge from the mid-60s to the mid-30s in about 90 minutes once the front passes, but it will be slow to drop much lower than that until early Thursday morning.

Freezing rain accumulations ranging from as little as a glaze to as much as 0.30” are possible; that could put some serious strain on trees and power lines as well as cause bridges and elevated surfaces to ice over quickly early Thursday.

Another big factor here is the bitterly cold air and the wind. Ice-laden trees and lines may be compromised by gusty winds over 20 miles per hour; soggy ground will not freeze quickly, so higher wind gusts (close to 30 MPH) combined with ice load could topple trees that would otherwise stand strong.

Heading to the weekend: Temperatures plunge to the teens Friday morning, and it stays cold in the afternoon: highs in the lower 40s. A slight warm-up begins this weekend with daytime highs in the 50s and overnight lows in the 20s. There is a small chance of some light showers Sunday, but the next good chance of rain looks to come later next week.

TONIGHT: Humid and mild. Patchy fog, scattered showers, and a few isolated thunderstorms. Low: 62. Wind: S 7-14. Rain: 80%.

WEDNESDAY: Rain and a few thunderstorms. Temperatures dropping to the 30s after sunset. High: 69. Wind: SW 10-20. Rain: 90%.

WEDNESDAY NIGHT: Rain changing to freezing rain overnight. Some accumulations of ice are likely. Low: 27. Wind: N 10-20. Rain/Sleet: 90%.

THURSDAY: Freezing rain and sleet in the morning. Cold and dry by afternoon. Wind chill in the 10s. High: 32. Wind: N 10-20. Rain/Sleet: 70% (before noon).

FRIDAY: Partly to mostly sunny. Cold and dry. High: 44. Wind: NE 5-10.

SATURDAY: Partly to mostly sunny. High: 52. Wind: WNW 3-9.

SUNDAY: Partly cloudy. A small chance of a shower. High: 53. Wind: NW 5-10. Rain: 10%.

MONDAY: Mostly cloudy, milder. Some showers possible. High: 54. Wind: NW 3-9. Rain: 20%.

TUESDAY: Partly to mostly cloudy. Spotty showers. High: 64. Wind: NE 5-10. Rain: 20%.

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