Good Friday morning to one and all--
Now it's time to get down to the nitty-gritty of Kentucky Derby week. Oaks day today and Derby day tomorrow. As the bets get placed, the weather now turns gray.
|HPC - Surface Map - Friday Afternoon|
This is the same storm system that brought 6-10" of snow to a large swath of Colorado and the central/northern plains states. It is running into interference from our large blocking high pressure system (the yellow line indicates the 'wall' its creating). As the system moves eastward, it weakens and much of its energy is squeezed northward. Nevertheless, it will make enough progress to bring the threat of rain to the Louisville area during the day. Here's another explanation of how it works:
|NAM - Wind-Field - Friday Afternoon||HPC - Projected Rainfall - Through Sunday Evening|
The wind-field demonstrates the powerful influence of high pressure to our northeast. Air moves onshore in the Carolinas and Virginia, bringing moisture toward the mountains and around/underneath to the western sections of the Ohio Valley. What happens at the mountains is that once the air goes up the slopes on the eastern side, it dries out on the western side. This is why constantly drying air is flowing through the River Cities area all the way to the Kanawha Valley. Moisture far aloft can certainly avoid the mountains, but this only results in higher cirrus and fair weather cumulus clouds locally rather than rain. Notice on the right-hand map the projected rainfall amounts indicate a sharp cut-off east of I-75. In fact, places like the Charleston metro area may well avoid rain entirely during the weekend.
|GFS - Saturday PM||GFS - Sunday PM||GFS - Monday PM|
Obviously we won't be able to completely miss this thing, but whenever the rain does make it here, it will be well appreciated. For folks that manage to hold out all the way to Monday you'll be about 2" down for the year, with the bulk of that missing rain occurring last month. We had a whole bunch of days with rain during April (14), but not much ever came of them. Expect to put a dent in that deficit early next week with several days of scattered showers.
|Regional Radar/Satellite with Warnings Tracking||
From the Storm Prediction Center (below): Click For a Larger Image
|Activity Overview||Storm Outlook||Watches||Potential Watches||Storm Reports|
|Temperatures||HD Doppler Radar||Estimated Rainfall||Active Warnings|
|Click For Larger||Click For Interactive Radar||Click For Larger||Click For Larger|
Have a great day everyone!