Long Range Trends: Thanksgiving Hurricane for Florida?

[HAltschule]

Hi,

This warm weather we're experiencing is wild for this time of year. In fact, it may be in the low 60's here in New York in another 10-12 days from now with additional warmth across the Eastern half of the country. Certainly no significant snow threat in the foreseeable future!!

Of real interest is the GFS which is generating a powerful Hurricane that is forecast to come up through the Caribbean, through the Yucatan Channel and make landfall along the Florida West Coast within a few days of Thanksgiving. WOW!! I wouldn't have expected to see that on the forecast charts.

Of course, it is very far out, but pretty wild to see such a powerful tropical system this late in the season threatening the Gulf Coast.

Anyone who wants to chime in on the Hurricane Potential and general long range forecast thoughts for this winter, please do so.

 

[Jim Bishop]

First I'd like to comment on the overall weather pattern, because there's talk about last year's warm November, and then the warm January. Then I'll get to the tropics.

We're seeing a good negative PNA pattern favoring troughing and low pressure in the Gulf of Alaska to the West Coast. I've heard this referred to as both the "fire hose" and "blowtorch". Both imply that low pressure in the GOL (Gulf of Alaska Low) pumps mild, Pacific air into the Western and Central U.S.

Last November and this past January this type of pattern was seen and sustained mild air even reached the East Coast. Now and over the next 10-15 days there isn't and probably won't be sustained very warm (+8 to +15) temperatures due to periodic cool fronts associated with shortwaves ejecting from the Pacific. So the blowtorch is in place but true blowtorch warmth isn't going to happen like it did back in Nov & Jan. This may have something to do with the both the east/west position and the strength of the GOL along with the stregth of the block over Eastern Russia/Western Alaska. Some positions may favor a higher frequency of shortwaves passing through the Great Lakes and bringing brief periods of cooler weather.

The most interesting aspect about this pattern is how it keeps the arctic air bottled up in Western Canada and Alaska. So if the North Atlantic Oscillation goes negative in the next 10-15 days there still won't be sustained cold air over the East because there won't be any cold air to tap! There will just be 'cool' snaps and likely brief. But if the NAO stays positive then intervals of very mild temperatures will persist. The 'blowtorch' needs to be turned off, so we need to get rid of that GOL!

The NAO forecast by the GFS Ensemble continues to show a trend into negative by the middle to latter part of November. Above normal sea surface temperatures around Greenland would certainly suggest that a switch to -NAO is likely. (Although there's been decent cooling off the Northeast Coast in the past couple weeks, so I wonder if that will drift northeast and cool the water near Greenland.)

It seems to me this pattern will break, but probably after Thanksgiving. I'm ready to see some good snow storms over the East Coast. Of course there's the scare of El Nino strengthening a lot more and December being very warm. I've seen both warm and cold December forecasts.

On the tropical side it's kinda funny that a couple early runs (18z & 6z) of the GFS did develop a tropical system in the Caribbean. The GFS usually does something really extreme beyond day 10. It isn't shocking considering a ridge should develop over the South Central U.S. as that GOL deepens, so the wind shear would weaken. But it's the GFS extended...give me a break!

 

[Bart_Comstock]

Well this would make that trip to Tampa the week of Turkey day a lot more interesting.

"Hey, Uncle Don pass the stuffing and the flashlights."
"Mom, the storm surge is getting in my sweet potatoes."

No, from what I have learned over the last two seasons is that since I am there it wont happen, or the storm will swing N. Ever planning a outdoor event and want to guarantee blue skies? Call me.