9:15 PM Sunday Update... I have no changes to my prior thinking, but I wanted to give you a little more insight into what will happen Tuesday and beyond.
Rain will be heavy across much of Arkansas Tuesday with a wintry mix across the north. By the afternoon, the surface low will move east and our winds will begin to come out of the west and northwest at speeds of 15-25 mph. Temperatures will tumble, but the best moisture will be gone by the time the subfreezing air arrives. There could be a change over briefly late Tuesday, but it won't be much if any. The real deal will be west and north of Arkansas. The northwest corner of the state will have some ice, then snow. The higher elevations of far northern Arkansas may also have a wintry mix turn to snow before ending with some accumulation. The southeastern part of the state could even get into a few thunderstorms. The temperature contrast across Arkansas Tuesday afternoon will be wild... 20s north to near 70 southeast. We're still 36-48 hours away (as of Sunday night) and things could still change, but probably not by much. This will a huge storm affecting millions of Americans.
Temperatures Thursday and Friday morning will be bitterly cold and I don't think the models have a full grasp on that just yet due to the fresh snowpack to the north. Our air will move over that snow and bring an extra chill.
I'll keep you updated Monday and Tuesday!
8 AM Sunday Update... Just had a very quick look at all the data this morning and it seems all the models are showing a track of the low pressure which would only bring wintry weather to northwest Arkansas. It's mostly a cold rain in central Arkansas with thunderstorms possible across the far south and southeast corner of the state. This will be a situation where temperatures across the state will be in the 20s northwest to near 70 southeast... a HUGE contrast. For those of you wanting winter weather, I know you must be disappointed, but on Tuesday, step back and watch this storm with appreciation. You will not often see a system so dynamic bring extreme types of weather to such a large area of the country. I wish I could bring the snow here, but it's just not in the cards this time.
There is a chance for a very brief change over to some light/snow or ice in central Arkansas late Tuesday, but I have big doubts about that. We may get a dry punch of air at that time which ends the precipitation. Some moisture will wrap around the storm and bring light snow to northern Arkansas. The one thing we definitely can count on is the cold weather following the system. I still think the difference between highs Saturday (77 in Little Rock) and lows by the end of next week, could be around 60 degrees. The air traveling over the fresh snow pack to the north will keep the temperatures chilled here.
Some of the models keep a piece of energy in the southwestern United States and eject it out late in the week. One model even tries to bring some wintry weather back into the state, but at this time, it's the only one doing this. I'll keep watching it for you. Again, Tuesday will be fun to watch the extreme nature to this storm across the central United States. It's our neighbors to our north and west who will talk about this for a very long time... enjoy mother nature at work.
I'll have another post later today and if anything changes (it always could), I will let you now A.S.A.P.
From a meteorologist at the National Weather Service in North Little Rock...
"IN EVERY FORECASTERS CAREER THERE ARE CERTAIN SITUATIONS WHICH ARE CLEAR-CUT. THE MODELS REMAIN CONSISTENT...THE FORECAST DOESN'T VARY MUCH FROM RUN TO RUN...YOU END UP WITH WHAT STARTS OUT AS AND REMAINS AN EASY FORECAST.
THIS IS NOT ONE OF THEM. FIRST...I'LL TALK ABOUT THE OVERALL PATTERN
DETAILS...THEN THE MODEL ISSUES."
It's the truth, this next storm is the king of challenges. To hang your hat on any particular model run is setting yourself up for a big time busted forecast. I don't think we will have a clearer picture until the arctic air really gets into the United States and the storm system in the Pacific Ocean comes ashore. I have seen model runs giving northwest Arkansas a foot + of snow only to have the next show 1 inch. Forgive me if I sound like a broken record, arctic air is not handled well by any model. Some do a better job and theoretically the NAM should see it better with its higher resolution and better interpretation of topography. However, the NAM has performed lousy this winter. Maybe this time it will redeem itself. The GFS keeps shifting the track of the surface low... south, north, south, north. The Euro had a BIG snow for much of the state just 2 days ago, it's now in the warm camp. I think for northern Arkansas there is a much higher degree of confidence in wintry weather. It's further south into central Arkansas where the low level arctic air will give forecasters fits. I have been forecasting for more than a decade now and have never seen a forecast bust too cold in this type of situation so you can see my worry with this. It's not snow that I'm concerned with in central Arkansas, it's ice and it all depends on that area of low pressure and how far south the arctic air penetrates. Right now I think a cold rain is a safe bet in Little Rock. As that low passes to the south and east, very cold air will pour into this region of the state. How much moisture will remain at that time? I think a dry slot of air COULD travel into our neck of the woods and choke off the moisture at that time. It's also possible for moisture to wrap around the area of low pressure and bring the wintry precipitation further south into Little Rock Tuesday night. Again, this is pure speculation right now as the models are having a difficult time.
Now the cold behind this system also varies with each model you look at. Right now, I have to side with the colder modeling for the period Wednesday through Friday for a couple of reasons. First, most of the data shows a 1044 mb + high coming out of Canada. There isn't much that will stop that cold air from flowing southward. It's like water falling down a mountain... good luck stopping it. Second, that air will be transported from the north over a fresh snow pack. This will keep the air chilled. It's those reasons I have highs not getting above freezing Thursday with lows in the teens.
I urge you not to think for a second that this forecast is etched in stone. Anyone who tells you they know exactly what will happen isn't telling you the full truth. The picture will become clearer soon and you can bet I'll be here to tell you all about it.
You can expect a BIG post Sunday... as if this isn't one.