December 18, 20205 yr Some could be seeing a white Christmas. The precipitation will start off as rain Thursday Wednesday evening as it traverse across Kentucky cold air will come in behind the rain field and turn some of the precipitation into snow. It really will depend on how fast the cold air can over take the rain and turn it in to snow. As of now it looks like the snow will fall east of I-65. I will be updating everyone as we get closer to Christmas.
December 18, 20205 yr As I've gotten older, I've become less of a fan of snow at Christmas. Actually, less of a fan of snow at any time. "Get off my lawn!" ?
December 18, 20205 yr 28 minutes ago, OlDog75 said: As I've gotten older, I've become less of a fan of snow at Christmas. Actually, less of a fan of snow at any time. "Get off my lawn!" ? I'm certainly no big fan. But I would at least like to see it every now and then.
December 18, 20205 yr Author Here's an update of the possible snow to end next week. I like to first talk about the set that could quite possibly give us a White Christmas this year. Along with the snow we will get a brief arctic blast that comes into Kentucky following the snow. The GFS 500 mb Height Anomaly (dam) map shows a low pressure system moving across the Great Lakes. A cold front will trail from the low down to Texas. As the cold front approaches Kentucky rain will break out ahead of it. The leading edge of the arctic air mass should catch up with the rain field as it enters western Kentucky during the evening on Wednesday. As the artic air overtakes the rain a possible wider snow field will form. The snow will travel across Kentucky on Christmas Eve before it exits early Christmas morning. Now lets discuss the possible snow accumulations. Please note that these are not official totals just a snap shot of what the models are showing now. The GFS is up first. Next from the Canadian. Last the European Model it is coming in with lesser amounts than the other two. We could see some temperatures from 10 to the mid teens Christmas morning. They could fall to the single digits Christmas night. I will be back for an update later this weekend.
December 21, 20205 yr Author Here's the Monday morning update for the possible snow Christmas Eve. The precipitation will start off as rain. As the cold air catches up with the back edge of the rain field it will change it over to snow. All three models I'm using for this update show this but at varying degrees. First the GFS. It show the rain ongoing in western Kentucky but artic air starting to change the back edge to snow around 7 pm EST. As the precipitation moves across Kentucky most of the rain changes over to snow. Most of the snow accumulations looks to be from around the I-65 corridor eastward. The snow looks to end during Christmas Eve evening with light snow showers and flurries. The European doesn't have the arctic air changing the rain over to snow until Christmas Eve morning and that occurs around the I-75 corridor eastward. It also has the snow ending during the evening on Christmas Eve. Most of the snow accumulations will be east of I-75. The Canadian also is showing the snow holding off until Thursday morning and ending Thursday evening. It too shows most of the heavier snow accumulations from around I-75 eastward. As everyone can see there is still some uncertainty to the exact timing and accumulation totals. I should start getting a good read on the possible snow by tomorrow morning. The time period will start coming into the range of the NAM. Have a good day.
December 22, 20205 yr Author This morning's update is showing some will see a white Christmas this year. As I figured we are starting to get a good read on the system that will bring snow to Kentucky. There is still some disagreement from the model on timing and amounts. So let's look at what the models are showing this morning. The NAM has the rain starting to change over to snow early Christmas Eve morning and continuing into the early morning hours on Christmas day. This change over looks to start just west of I-65 then progress in an easterly direction. Then tapering off to flurries before exiting eastern Kentucky. The GFS has the changeover a little further west than the NAM. Also it is showing the more heavier snow amounts in eastern Kentucky. It also has the snow starting earlier Christmas eve morning than the NAM. The European model is coming in warmer than both the NAM and GFS. It is showing a period of freezing rain as it crosses Kentucky before that change over to snow around the I-75 corridor. The timing is early Christmas Eve morning and exiting Kentucky during the evening. The Canadian is close to what the NAM and GFS is showing. Also showing some areas of possible freezing rain. It is showing the snow starting Christmas Eve morning and continuing to Christmas morning. Now for the possible snow accumulations. NAM GFS The European The Canadian The models showing some freezing rain are showing lesser amounts of possible snow accumulations. I will be making my first call for snow this evening.
December 22, 20205 yr Author Tuesday evening update: It really is starting to appear that portions of Kentucky are in for some moderate snow accumulations starting on Christmas Eve through Christmas Day. I will be showing everyone the three normal models I use plus a new one. First I will start with the NAM. The precipitation will start off as rain. Two things to take note of. First, the 540 line. This line represents air that is cold enough to produce snow. It shows the line catching up faster with the rain field and so the rain will turn to snow faster. Second, The low pressure system that is forecast to form over Alabama and move in a north easterly direction and pass just to the southeast of Kentucky. This will intensify the precipitation field to produce more snow accumulations. The GFS is showing the the same low but it forming around the Tennessee/North Carolina border. It this happens the forecast track will take the heaviest snow to east of Kentucky. Canadian Model is in some what of agreement with the GFS. The one difference is it is show a warmer air mass to mix in with with the snow. This will cause some freezing rain possibilities. This is the new model I mentioned earlier. It is the RDPS short for Regional Deterministic Prediction System. It is also from Canada. It is updated the same as the NAM. It is showing pretty much what the Canadian is showing except with the possibility of some wrap around snow. The difference being the starting point of the low is pretty much the same as the NAM and GFS. The other difference being it has the snow continuing for much of Christmas Day while the other models show the snow ending earlier Christmas Morning. Now let's look at what each model is showing for possible snow accumulations. The NAM The GFS is showing much the same possible accumulation but east of Kentucky in West Virginia. The Canadian GDPS The Canadian RPDS All of the models are showing the heaviest possible accumulations from around the I-75 corridor eastward into eastern Kentucky. For my first call of snow I'm calling for 6-8 inches for most of Kentucky east of I-75. 3-5 inches just west of I-75. From about I-65 to just west of I-75 2-4 inches will be possible. Remember these totals may change. I will post a quick update in the morning as I have to be at work at 5 am. My next update tomorrow evening maybe later as the wife and I will be traveling to Bowling Green for Christmas. Take care and prepare as you see fit.
December 23, 20205 yr Author I will make my second call later this evening. The later model data has come down some on the totals but that is to be expected. I want to see a couple more model runs before I make my second call.
December 23, 20205 yr Author 44 minutes ago, PP1 said: What exactly is the I-75 Corridor? Areas adjacent to or near-75 on either side.
December 23, 20205 yr 53 minutes ago, nWo said: Areas adjacent to or near-75 on either side. So is Florence considered the I-75 Corridor even though it is in the northern part of the state?
December 25, 20205 yr Author On 12/23/2020 at 12:32 PM, PP1 said: So is Florence considered the I-75 Corridor even though it is in the northern part of the state? Yes when I use the term it spans the length of I-75 north to south.
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