Major Winter Storm Potential Sunday/Monday

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BLOG: Let me apologize for the blog issues today… we are going to a distributed platform so you won’t have to see the “high traffic mode” again, but that probably won’t happen until tonight. We are slammed with an extremely high level of traffic this afternoon, and we know it will remain at that level for the foreseeable future. We believe the distributed platform will eliminate the outages.

THE ALABAMA WEATHER SITUATION: First off, I encourage you to watch the Weather Xtreme video so you can see all of the graphics and maps that go along with this discussion… often they tell a much better story than I can with words. Having said that… here we go…

TOMORROW/SATURDAY: No weather issues. Dry and cool with a partly to mostly sunny sky. The high tomorrow will be in the low 50s, followed by upper 40s Saturday as colder air begins to drop south into the state.

WINTER STORM THREAT GROWING: Confidence is now high that much of the Deep South will be impacted by a major winter storm Sunday and Monday, but as you know the devil is in the details, and we aren’t ready to go there until tomorrow morning. But, with good model agreement, we can pretty much look at the overall situation with a higher level of confidence this afternoon.

SUNDAY: A low pressure center will form in the Northwest Gulf of Mexico, south of Lake Charles, in response to a strong short wave moving through Texas. The precipitation shield from this system will move initially into Southwest Alabama Sunday morning, and this precipitation could begin in the form of freezing rain or sleet if it begins early enough. This precipitation will ultimately cover the entire state by Sunday evening.

HEAVIEST SNOW: At this point, it looks like heavy snow is a very real possibility over the northern third of Alabama. Areas north of U.S. 278, or north of a line from Hamilton to Cullman to Gadsden, could see 4-8 inches of snow Sunday afternoon through Monday morning. The main period for this heavier snow will be from around 12:00 noon Sunday through 12:00 noon Monday.

GREATEST CHANCE OF ICE ISSUES: To the south, snow is likely over Central Alabama, but model data also suggests that warmer air in the 3,000-6,000 foot range could change the snow over to freezing rain at times. This is the most difficult part of this forecast; resolving the exact type of precipitation and potential for icing along the I-20 corridor (Tuscaloosa, Birmingham, Anniston). For now will just mention a chance of snow and freezing rain for this strip of the state Sunday night into Monday morning. There could be enough ice load for significant travel issues and maybe even some power outages, if the freezing rain lasts long enough.

We should note here that freezing rain is not sleet; freezing rain is liquid precipitation that falls when surface temperatures are below 32 degrees. This, in turn, coats everything exposed with ice, and can bring down trees and power lines if the ice load is heavy enough. Sleet, of course, is precipitation in the form of small ice pellets, and rarely causes major problems.

Father south, some snow or freezing rain is possible all the way down to U.S. 80, or a line from Demopolis to Selma to Montgomery to Opelika.

BOTTOM LINE: We will have our first accumulation potential maps here early tomorrow morning, but everybody in the Tennessee Valley and the other parts of north Alabama (mainly north of U.S. 278) needs to prepare for heavy snow Sunday and Monday, and farther south, folks in Tuscaloosa, Birmingham, and Anniston can expect a wintry mix of snow and freezing rain, with potential for some accumulation as far south as U.S. 80.

Travel could become difficult, if not impossible across North Alabama Sunday night into Monday.

But again, we like to be within 48 hours of a winter weather event before we really begin making specific accumulation and impact forecasts, so the package here early tomorrow morning will be the one to really pay attention to.

REST OF NEXT WEEK: The snow will wind down Monday, but flurries are possible Monday night and Tuesday in the cold air that will cover the Deep South. Highs will be only in the 30s. We warm up a bit toward the end of next week.

COLD WAVE JAN 17-22: We still have great concern over a major cold wave later in the month, with air that has origins in Siberia. See the Weather Xtreme video for more on this… needless to say, way to early to be specific.

WEATHER BRAINS: Don’t forget you can listen to our weekly 30 minute netcast anytime on the web, or on iTunes. This is the show all about weather featuring many familiar voices, including our meteorologists here at ABC 33/40.

FOLLOW ALONG: Here are our weather team Twitter accounts….

I had a great time today visiting the 3rd graders at Greystone Elementary in Hoover… be looking for them on the Pepsi KIDCAM today at 5:00 on ABC 33/40 News! The next Weather Xtreme video will be posted by 6:15 a.m. tomorrow…

Tags: winter storm

Category: Alabama's Weather