There weren't many changes made to the Thur/Fri forecast which was mentioned in my previous post (Monday night). However, the models have come to more of an agreement. Here is the latest look...
7 AM THURSDAY: The onset of the precipitation is slow to start according to both the NAM and the GFS. The GFS expects precipitation in the form of rain and rain/snow mix to enter E. Kentucky around 7 AM (far left panel). The northern extents of Southern Ohio will likely see pure snowfall at the onset, with rain/snow mix more likely for areas along the Ohio River. The NAM has the precipitation in Kentucky further westward than the GFS but otherwise, there is general agreement.
1 PM THURSDAY: According to the GFS, pure snowfall is expected in S. Ohio, with much of West Virginia and Kentucky holding on to a rain/snow mix (with the exception of the far northwestern extents of Kentucky). This can be seen in the second panel from the left. The NAM is still a bit slower with the precipitation pushing through West Virginia but the location of rain/snow line is similar, along with the location of the heavier precipitation (indicated by the blue and green shading).
4 PM THURSDAY: It is going to be a messy commute home from work/school. The GFS for this time period shows a strong snow band pushing through S. Ohio, E. Kentucky, and West Virginia (second panel from the right). The NAM agrees with the GFS for this time frame. This is when we should start to see the snowfall sticking to the roadways (especially in S. Ohio where precipitation has fallen in the form of snow for quite some time already).
4 AM FRIDAY: We will see a chance of a few flakes lingering in West Virginia during this time; with a more consistent snowfall sticking around the mountains (refer to the far right panel). The GFS expects the snow to end after this time frame. However, the NAM expects the snow to linger into the mountains for several hours more.
I am leaning toward the NAM's forecast in regards to the snow lingering in the mountains on Friday. Upsloping winds should bring persistent snowfall to the mountains, even after the bulk of moisture exits our region. Refer to the above picture of the strong northwesterly flow we seeing in our region for 7 AM Friday. This is ideal for upslope.
This is the snowfall forecast as of this evening (For Thursday through Friday)
Note that a heavier band of snow is also looking to fall in areas of Ohio. The reasoning for this is because the onset of pure snowfall is starting earlier in Ohio when compared to the rest of the region. I will update this as the new model runs come out...
Here is the latest look at the forecast for the Sunday/ Monday snow system...
The GFS expects the precipitation associated with this system to affect much of the tri-state region by 7 PM Sunday evening. We should see pure snowfall in much of Ohio and N. Kentucky. West Virginia and much of Kentucky are closer to the rain/snow line (5400 m height) at the onset of the precipitation. So, it will likely be a rain/snow mix to start. Pure snowfall is expected to fall in these mentioned areas within the next hour or so from this time frame.
Then by Monday morning, the GFS shows the snowfall diminishing and falling in only SW West Virginia. Overall, the GFS expects the storm to be rather short lived (in our region at least).
The above picture shows the difference in the Euro (left) and GFS (right) forecast for Monday morning. Note how the Euro keeps the center of the low further inland (over upstate NY) and expects the low to be strong (994 mb). This is vastly different from the GFS, which has the low off the east coast and quite a bit weaker (refer to the picture of GFS sea level pressure for 7 AM Mon) . In regards to the temperatures, the GFS is catching up to the Euro, showing -12°C air moving in at the 850 mb level (Euro is about -8°C). Note that the GFS still doesn't show the coldest temperatures dipping into the country like the Euro does (indicated by the white color... -30°C). Regardless, there is more agreement on the fact that a strong cold blast is heading our way next week. Overnight lows are expected to dip into the single digits at the surface. BRRRR!
Bundle up and safe travels everyone!