4PM Monday Update... This will be a quick update. If you haven't read the in depth post below, I think you will find some good information. The 18Z model runs are out now and I really have no changes. I still expect a narrow band of snow to push through the state tonight from west central to central to east central Arkansas. Also, some moisture may get drawn into southeastern areas for some sleet and snow accumulations.
We can already see the wave of moisture coming out of Colorado and Kansas and it looks "healthy". There's banding seen on the radar. If this continues, those localized areas of higher amounts COULD be realized. There should still be a 2nd wave Tuesday night into Wednesday morning for southeast Arkansas. More on that later.
10 AM Monday Update... The latest runs of the NAM and GFS are in and both are still having problems. However, they do indicate the chance for accumulating snow, but much less than thought just a couple days ago. When it does show snow, the GFS has been consistent with a very narrow corridor from west central into central and east central Arkansas. The NAM on the other hand is extremely inconsistent. I was talking to Ryan Vaughan Sunday. He's the chief Meteorologist at KAIT in Jonesboro. We both talked about how poor the NAM has performed lately and he's not even really using it. With all that said, PLEASE READ the morning post below for more specific information. Here's the NAM and GFS morning run from weatherbell.com
|The morning run of the GFS continues to show a swath of light snow accumulations from west central to east central Arkansas. This is indicating amounts 2'' or less. Notice the system picks up its intensity as it moves east of Arkansas.|
First of all, that wave of energy for Monday morning is here and producing some light snow and sleet across central and northern Arkansas as we discussed Sunday. This should move through this morning and we'll get a break. Then the more significant potential for winter weather will enter the forecast.
As I said on the air Sunday, this is one of the toughest snow forecasts in a long, long time. Two runs of the GFS and NAM came back Sunday with less moisture for the situation Monday night into Tuesday morning. As a matter of fact, it came back with almost no moisture. I cautioned on the air the winter storm watch could be adjusted and indeed it has. A winter storm watch means there's the potential for a winter storm with accumulations greater than 3''. A winter weather advisory means there's the potential for accumulations of 3'' or less.
I also cautioned and said the data could come back with the moisture in future runs and that is exactly what happened this morning. The NAM continues to be ho hum about this, but the GFS is back with it again. In all honesty, the NAM has not been a good model this winter. I usually make fun of the GFS when compared to the European model, but it has performed far better recently (GFS).
In a blog post a few days ago, it looked like this may come out in a couple pieces (energy). One coming through the state tonight and the other one Tuesday night into Wednesday morning. For the longest time, the 2nd piece Tuesday night looked like it would stay south of the state, but recent trends bring it further north into southern Arkansas. This was my worry.
So where are we now? The guidance has been all over the place from run to run. Since the GFS has performed better this winter, I think it's wise to watch this even though it has disagreed with itself from run to run. EXHAUSTING!
There still appears to be a piece of energy coming through tonight which will bring a chance for accumulating snow from Fort Smith to Little Rock to east central Arkansas. It's a narrow corridor. The features moisture levels appear to be less compared to the data last week. With that said and all the model variability, let's keep an eye on this thing! I think 1-3 inches would be a good forecast, but we will need to watch if any "banding occurs" which could enhance that in local areas.
Another piece of energy will fly out of the west and bring a mixed bag of precipitation Tuesday night into early Wednesday morning. The target area for the best chance will be southern and southeast Arkansas.
The following maps of the GFS are from weatherbell.com
|Between midnight and 6AM Tuesday, it has the band of snow again and it shows enhancement from central Arkansas eastward. Sleet would be possible (orange) over the SE.|
|This should rapidly come to an end Tuesday morning after 6AM as this wave moves away.|
|Tuesday night into Wednesday morning the next wave could push moisture into southern Arkansas in the form of sleet and freezing rain... maybe some snow. The worry here is that the precipitation shield comes further north. Stay tuned.|