UPDATE 9:30 A.M., 10/13: The storm-system highway moves a few states away; classic October weather sets up for Southwest Virginia
UPDATE 9:30 AM, 10/13: A chilly morning across Southwest Virginia, with some scattered frost, will develop into a mostly clear and rather cool day, with highs mostly in the 60s. Again, classic October weather for football games and other outdoor autumn activities. Adding to the tropical thoughts below. Tropical Storm Rafael has formed near Barbados. It will miss the U.S. by a wide berth but might stir up a little extra surf along the coast as it tracks north. Meanwhile, a cold front that will affect us Monday is expected to trigger some severe storms in the central U.S. More on that front’s effects on us in my next blog post tonight. END UPDATE
There is still an Atlantic tropical season going on, but don’t blink, or you’ll miss Tropical Storm Patty. While its location just east of Bahamas would often be favorable for affecting the U.S., it has no hope of survival or westward tracking against the progressive late autumn/early winter kind of weather pattern that has set up. The last cold front that came through here will introduce too much dry air into Patty and likely do her in by Friday night. From here on out, just about the only way a significant tropical system will affect the U.S. is if it somehow gets into the Gulf of Mexico and gets swept northward by a cold front.
Another dry cold front will pass through on Friday, as happened Wednesday. You might notice a little extra breeziness with its passage. It will reinforce the temperature regime we have — highs in the 60s to low 70s and lows in the mid 30s to low 40s will continue today and Saturday. We are going to be off of the main drag for storm systems through the next week — the jet stream boulevard will extend from the central Plains toward the Great Lakes, illustrated well by where the most rainfall is projected on the Hydrometeorological Prediction Center 5-day forecast map. The inset maps at left, both from the HPC, show low-pressure systems on Sunday (top) and on Thursday (bottom) of next week in almost the same location. The first one on Sunday will drag yet another cold front through Southwest Virginia, which may find just a little bit more moisture than the last two have and squeeze out a few showers late Sunday into Monday. This storm system will likely trigger a multi-day outbreak of severe weather in the central U.S., with tornadoes a strong possibility, as winds aloft will be strong and changing direction with height. This scenario may well repeat itself with the second low-pressure mid to late next week. Expect more rain and more severe weather through the central U.S. into the Great Lakes. The second low late next week may be a bit stronger, and might tap a bit more cold air — the early week storm will mostly be pulling in cool, but not exceptionally cold, Pacific air. The late-week storm has more potential for significant rain in our neck of the woods than the first storm, as it may be able to better tap Gulf moisture. Details remain sketchy on the later storm, including just how much cold air it will pull down — still looking like mostly a Pacific air mass from this distance.
Until thicker moisture is pulled up, the fronts passing through Friday and Sunday will continue to reinforce the air mass we have going — mild to warm days (60s to low 70s), cool nights (mostly 40s), cold in the spots (some 30s), and mostly dry throughout. The warm days/cool nights scenario with no extreme rain or wind should continue to advance our region’s fall colors. This is classic October weather for Southwest Virginia.