Quadruple Whammy for Contiguous U.S.UPDATE OCT. 5: I will post a blog on Sunday with a summary of the wild weekend of weather the U.S. is experiencing.
For what may be the first time in modern records, the contiguous U.S. is facing a simultaneous threat from a tropical storm landfall, blizzard, tornado outbreak, and extreme wild fire event. Or, as Chrissy Warrilow of The Weather Channel put it, a veritable Weather-Palooza (a ‘Palooza’ is a musical event featuring four or so major acts performing at the same time).A map of how the ‘weather-Palooza’ is playing out across the lower 48 U.S. states.
Map courtesy of Stu Ostro of The Weather Channel.Surface conditions as of 18z October 4th.
Map from NCAR.
This is just preliminary blog on the events that are expected to unfold over the next 48 hours (Friday-Sunday). So far, only the blizzard in the western high Plains and Wyoming has actually manifested itself already (as of Friday 3pm EDT). However, here is what should transpire:1). Tropical Storm Karen:
Karen is expected to make landfall somewhere between New Orleans and the Florida Panhandle Saturday night or Sunday morning. A hurricane watch and tropical storm warning is in effect for the area. There is, however, a fairly good chance that by landfall the storm will have weakened to below tropical storm status (and a much smaller chance that it will have strengthened to a hurricane). Follow Jeff Master’s blog for all the latest news concerning Karen.The National Hurricane Center’s tracking forecast map for Karen as of 1 p.m. CDT Friday, October 4th.
NHC2. Blizzard in the Plains:
One of the most significant early-season blizzards on record is impacting Wyoming and western portions of South Dakota and Nebraska. Blizzard warnings are in effect for the area. Already up to 24” of snow has fallen at a few locations in central and eastern Wyoming (actually up to 36” now reported in the mountains south of Casper) as well as in Lead in the Black Hills of South Dakota.As of 9:30 a.m. CDT Friday October 4th, at least two feet of snow have already accumulated in Lead, South Dakota. The fence in the photo above is 4 feet tall. Heavy October snowfalls are no stranger to Lead: 38.9” accumulated there on October 26, 1996 and 33.4” on October 5, 1998.
Photographer not yet identified.3. Red Flag (Wild Fire) Warnings:
A very intense Santa Ana wind event is ramping up in Southern California threatening Los Angeles and Ventura Counties with wild fires over the next couple of days. Wind gusts in excess of 70 mph are expected. With no significant rainfall since last Spring the region is at significant risk (as it often is during October) for a catastrophic wild fire event. The NWS-Los Angeles office has declared that the situation is the direst for the past 5 years. The winds are expected to ramp up Friday night and peak on Saturday. Already in the San Francisco Bay Area high winds up to 60 mph (in the Oakland Hills) have caused spotty power outages and minor tree damage. However, the Bay Area received a good soaking rain in late September and a few showers last Monday, so, unlike southern California the wild fire threat is not so great (although a wild fire burned 375 acres in Napa County last night).4. Tornado and Extreme Storm Outbreak
There is a high likelihood of an outbreak of severe storms and tornadoes today (Friday October 4th) and tomorrow for portions of the Upper Midwest, especially Iowa where Dr. Greg Forbes of TWC has given a TORCON 6 rating for the northern portion of the state (this means a 60% chance of a tornado forming within a 50 mile radius of any given location in the area). This is his highest tornado threat warning issued for anywhere in the U.S. over the past two months. The first tornado warning has just been issued for northeastern Nebraska as I write this (as of 5 p.m. CDT).A map of the area in the central U.S. likely to see severe thunderstorms (in yellow and orange) sometime over the next 24 hours).
Map from Weather Underground.Summary
The only months of the year that a ‘quadruple whammy’ of extreme weather events could occur, such as what may happen today and this weekend, are May, October, and November. Only during these months could a tropical storm landfall, blizzard, tornado outbreak, and extreme wild fire event all conspire to affect the U.S. at the same time. Here is the latest Severe Weather Map issued by Weather Underground:You can view the latest updated version of this map here.
I will update this blog later today and over the weekend as this unique event unfolds.
Christopher C. Burt