***Winter Storm Warning is in effect until 6 AM Saturday***
Thursday Evening Winter Storm Update
Weather data continues to indicate a high impact winter storm will impact the Bowling Green, KY region overnight tonight and into Friday. A strong area of low pressure will form in response to an upper level trough entering the region. This will spread moisture over the region, leading to copious amounts of ice and snow for south-central Kentucky.
Synoptic Discussion – Valid 5 PM CST
An upper level amplified trough continues to move toward the region. As of 5 PM, widespread divergence is noted downstream of the trough axis. Divergence brings about lift in the atmosphere, which can help lead to the formation of clouds and precipitation.
In the mid levels of the atmosphere, a jet streak is noted rounding the base of the trough axis located in eastern Texas. This is forecast to move to the east, leading to widespread, enhanced divergence in the Tennessee Valley region.
Low level winds are out of the south around 10 to 15 knots. This is leading to warm air advection across the area. This will make it possible for some sleet and freezing rain as temperatures around 5,000 feet will be above freezing, while temperatures on the surface are forecast to be below freezing. The low level jet is forecast to increase in strength to the south of the region during the overnight hours, leading to the northward transport of moisture into a cold environment.
Temperatures across south-central Kentucky as of 5 PM were in the low 30s. Again, temperatures are forecast to remain below freezing, allowing for some freezing rain and sleet before transitioning fully to snow. A low pressure center was located over southern Mississippi and southern Louisiana. This should strengthen and move northeast with time.
A strong low level jet, on the order of 40 to 50 knots, is forecast to develop across northern Alabama, northwest Georgia, and southeast Tennessee around midnight. As mentioned earlier, this will lead to moisture advection across south-central Kentucky. Low level temperatures will be above freezing, however surface temperatures will be below freezing. This will result in a mix of freezing rain and sleet as precipitation begins across the region.
By 3 to 5 AM, low level atmospheric temperatures should decrease to create a sleet and snow mixture. By this time moderate to heavy precipitation should be moving into the region from the south and southwest. Everything should begin sticking immediately due to temperatures being below freezing.
At 5 to 7 AM a changeover to all snow should occur. The temperature profile through the column should be below freezing by this time, allowing for the dominant precipitation mode to be snow. The heaviest snow will likely impact south-central Kentucky around noon on Friday. Snow should diminish from west to east across the region as low pressure continues to depart the region and high pressure moves in.
So what does all this mean for Bowling Green?Expect all surfaces to get slippery during the early morning hours as freezing rain and sleet set in after midnight. Freezing rain accumulations up to 0.25″ are possible, however accumulations between 0.1″ – 0.2″ are more likely. This matches the National Weather Service forecast nicely.
Heavy snow will move into the region on Friday. Snow may be very heavy at times, leading to near zero visibility. Please stay off the roads if at all possible. Generally, I expect 8″ – 12″ to fall around Bowling Green, KY. However, it should be noted that if a heavy snow band sets up and stays stationary, snowfall amounts well above 12″ will be possible. This also matches up well with the National Weather Service forecast.
Wind will also be an issue on Friday. Sustained wind speeds of 10-15 mph, with gusts as high as 25-35 mph will be possible. This will lead to blowing snow, and may result in blowing snow as well as tall snow drifts.
A lot can go wrong with this forecast. Of my time with Wx Or Not, this is the most complicated forecast I have put together. This can likely be correlated with the longevity of the post (sorry!). However, several factors go into forecasting a winter weather event.
If the low pressure system moves any amount, it will have an effect on snow and ice totals. If the storm track is further north, more ice and less snow can be expected. If the storm track is further south, little ice and more snow may be expected.
The temperature profile above Bowling Green has a lot to do with what happens at the surface for Bowling Green. If the temperature profile is warmer than expected, more ice can be expected, with lesser snow amounts. However, if temperatures at the surface rise above freezing, a plain rain may be expected, with a gradual transition to snow.
Hopefully this makes things a little clearer. It is important to remember that a forecast is always evolving, so be sure to come back tomorrow morning for a fresh forecast. In the meantime, grab some bread and milk; but most importantly, freak out.