UPDATE 6 PM, 10/23: High of 77 at Blacksburg was 1 degree off a record for the date (78 in 1978), while Roanoke’s 82 was 2 off the record for the date (84, 1941). Similar temperatures likely Wednesday and Thursday. The front and rude slap of cold air still due by Monday or so. Big questions remain with the interaction of Tropical Storm Sandy and the front early next week, and just how much direct effect we will have. Looks like it might — MIGHT — be a much bigger deal in the Northeast. Either way, windy cold likely early next week, and probably some mountain snow showers. END UPDATE
UPDATE 7:45 AM: Forecasted highs in the upper 70s could challenge records in the New River Valley — Blacksburg’s record high for Oct. 23 is 78 dating to 1978. Roanoke may push into the low 80s today — the record for Oct. 23 is 84 set in 1941. The next two days will most likely be similar. The latest European forecast model continues to show a powerful low developing as Tropical Storm Sandy is absorbed into a jet stream trough, moving it toward New England next week, then into southern Canada, which would rotate lots of windy cold and maybe snow showers into our region. The GFS model continues to keep Sandy offshore and moves the hybrid system toward Newfoundland. Much remains uncertain, so keep monitoring it closely.END UPDATE
As projected, southwesterly wind flow is bringing in warm, dry daytime weather through the work week in Southwest Virginia. Roanoke might clip 80 a day or two this week, but that won’t set any records, which are in the mid 80s this time of year.
The weather geek world is abuzz with a bizarre and potentially historic weather setup developing for next week — or maybe not. The European model has been depicting Tropical Storm Sandy, now in the Caribbean, becoming captured by the strong, deep jet stream trough digging into the central and eastern U.S. over the weekend and early next week, the one that will slam the door hard on our unseasonable warmth of this week. The result would be that the energy of Sandy would be absorbed or converted into a hybrid/subtropical system, then becoming an incredibly powerful extratropical low (a “regular” non-tropical low pressure system, if you will) which could get pulled northwest well inland. The results of such a scenario could be jaw-dropping: Widespread damaging winds over several states, enormous storm surges over a much wider area of the coast than a normal hurricane would cause, torrential rainfall amounts, and quite possibly, huge snowfall totals (feet of heavy, wet snow) wherever the tropical moisture could be advected into and condensed within Arctic air that may become wrapped into the low. BUT … there are just too many moving parts and variables to project such a Halloween nightmare with much certainty just yet. First, the exact strength and track of Sandy are in question. So is the location, strength and timing of the trough and the Arctic front it is pushing along. And just how much does the tropical moisture drawn into the system modify the Arctic air? Minor differences could have major impacts on the development, track, strength and resulting effects of any potential storm system next week. While the 0Z Euro model favored bringing the storm in near Delaware and moving it to the eastern Great Lakes, the later 12Z runs bring it more toward New England. And the latest American Global Forecast System (GFS) model runs keep the tropical system well offshore. The Hydrometeorological Prediction Center’s weather map is somewhere in between, with a strong low off the North Carolina coast headed north-northwest by Monday (inset at left). Right now, the sheer upside potential of what could happen warrants vigilance for anyone in the eastern U.S. The wide range of possibilities, which include a much weaker low that stays mostly offshore with relatively minor impact, do not yet warrant any extreme actions or reactions to the weather setup. Most scenarios at this time would favor the worst impacts occurring NORTH of our region, though some windy, unseasonable cold and mountain snow showers will occur in almost all scenarios early to mid next week, even those without a strong low very close to us. Let’s just keep an eye on it and try not to run with the hype that is inevitable and already ongoing.