Offspring of Isaac drifts back into Gulf; multiple cold fronts to push into tropical moisture over Southwest Virginia
Your comments and our discussion on the last thread about the “hype” surrounding Hurricane Isaac inspired me to write about that in today’s Weather Journal column (linked here).
Isaac — which we first started to talk about on Aug. 21 — just won’t go quietly into that good night. The former hurricane split into two circulation centers inland, one now a low-pressure system over the Northeast. The southern piece has wobbled southward back to the Gulf Coast and may drift back over the Gulf of Mexico today. The National Hurricane Center gives this “son of Isaac” a 20 percent chance of redeveloping into a tropical cyclone. If it were to redevelop and then strengthen into a tropical storm, it would be a judgment call by the forecasters at the National Hurricane Center whether to simply call it Tropical Storm Isaac or to move on down to the next name on the list, Nadine, which would make it a “daughter of Isaac” I suppose. (There is a Tropical Storm Michael now, in the open Atlantic — and Tropical Storm Leslie, which may hit Bermuda and possibly Newfoundland later this week). In 2004, Hurricane Ivan came inland in the Florida Panhandle, then broke into 2 pieces over Virginia. One piece of it moved back over the Atlantic, got carried south and then west over Florida, then regained tropical storm characteristics in the central Gulf of Mexico before making a second landfall as the controversally renamed Tropical Storm Ivan over eastern Texas. (Ivan’s loopy 2004 track linked here.) Other tropical cyclones that develop from a fragment of a former tropical system have been given a new name, if it’s determined it’s more of a by-product of the old storm rather than a main part of it. Chances are still slim that it will become a tropical storm, so this discussion may be moot, just something interesting to consider.
Meanwhile, back home, a weak cold front is pushing into some of Isaac’s leftover moisture in our mountains, and we are seeing some enhanced showers this morning. Cold fronts will start to be our weather focus, with at least 3 different ones affecting us through early next week, the last of which will bring a shot of cooler, drier weather that may push some fall-like temperatures (60s-70s highs, 50s lows, some 40s) into our region the early to middle part of next week. Until that final push of Canadian air makes it through, we won’t entirely get rid of this sticky tropical moisture, and showers and storms will be a threat most days — though perhaps there will be one summelike warm to hot (80s, some low 90s) and mostly dry day on Friday. These fronts should also shunt Isaac’s offspring eastward toward the Florida Peninsula.