Isolated rain showers along with drizzle/mist will be ongoing across the Valley for your Monday. Temperatures will be slow to warm with a north wind around 10 mph. Those in northwest AL and southern TN will only make it into the low-to-mid 40s for highs while the HSV Metro and northeastern AL make it back to the mid and upper 40s. A frontal boundary settles to our south through the day, keeping the cold air in place.
Overnight, that front lift back to the north as a warm front. Our low should occur around midnight with temperatures warming through the early morning hours.
Scattered rain showers will be ongoing Tuesday. Winds will be out of the south in the 10-15 mph neighborhood. By the afternoon, highs will make it into the mid-to-upper 60s. A few rumbles of thunder are possible. A strong cold front will approach from the northwest overnight into Wednesday.
Our severe threat with this system remains low. That being said, our window for stronger t'storms will be open from Tuesday evening through Wednesday morning. Gusty winds would be the primary concern with any stronger t'storms overnight. A brief, isolated tornado is not out of the question.
The bigger concern, and potential for more widespread significant impacts with this system is due wintry weather late Wednesday into Thursday.
A strong cold front pushes into the area Wednesday morning. Winds switch around to north, and should be breezy behind the front. Sustained winds could be as strong as 10-20 mph during the afternoon with stronger gusts.
Afternoon temperatures will fall throughout Wednesday. We may start the morning near 60, but by 3 in the afternoon, temperatures could range between 35-40. A cold rain will be ongoing during the afternoon.
Our concern then shifts to rain converting to freezing rain early Wednesday evening as surface temperatures drop below 32. That change happens first in northwestern AL and moves southeast with time through Wednesday evening.
Freezing rain could be ongoing for several hours in the Valley overnight. Although it's a little too early to pinpoint exact totals, some may see upwards of 0.25" of ice overnight. By Thursday morning, any moisture left will change briefly to sleet and then to all snow.
Snow amounts should be minimal, but 1-2" of snow can't be ruled out for Thursday morning. The highest totals should occur towards the Shoals where the change to snow happens first.
The potential exists for significant disruptions to travel Thursday morning. Areas that see more ice may also be looking at power outages as well.
This is still a developing system...it's important to check back later in the week for more updates. In the near future, a winter storm watch may be issued. Later in the week, if wintry weather continues to look likely, that watch would be upgraded to warnings and advisories.
-Meteorologist David Ernst