Another Subtropical Atlantic Storm?

Update, December 7, 2013, at 11:08 a.m.: The NHC, as usual, was right. They have issued their last advisory. The area of interest is diminishing, and it looks like the second storm that was shown earlier in some of the models isn’t going to materialize. It’s still bad weather out there, but there isn’t going to be a subtropical storm born out of it.

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Update, December 6, 2013, at 11:09 a.m.: The NHC has lowered the chances of development back down to 20% this morning and believes that the storm will soon weaken and head north.

two_atl

Ordinarily I would say that’s that, but the GFS shows another storm developing to the west and absorbing this system to become fairly strong. The current GOES satellite imagery seems to show that happening:

Storms

Most probably the only land that will be affected by this stormy weather is the Azores. Whether the NHC scenario or something along the GFS model occurs, the resulting low pressure will be absorbed into the Westerlies and bring wet and windy weather to Iceland/Northern Europe.

However, the current US Navy NOGAPS model gets kind of crazy, showing the two cyclones having a Fujiwhara interaction before the stronger absorbs the smaller one in about 84-96 hours and then goes racing off to smash into Northeastern Northwestern Africa, which rather reverses the usual order of tropical cyclone development. This is a very unlikely outcome but sure would be dramatic to watch.

Will stay tuned.

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Update, December 5, 2013, at 2:49 a.m. p.m. Eastern: Well, this afternoon NHC raised the chances of a subtropical storm a little bit to 30% over the next five days.
 

NOAA/NHC

NOAA/NHC

Notice the thicker clouds in the circle – those are increased thunderstorms, a sign of intensification. It looks like that’s happening because of the interaction with the linear system to the west, but I’m not enough of a meteorologist to know exactly what’s going on there.

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Update, December 5, 2013, at 9:18 a.m. Eastern: Here’s fairly recent visible imagery on the area of interest – click the image below to enlarge.

Looks like it’s already starting to interact with that western system. What a large area is involved in the circulation (though of course it’s not all storminess).
 

Just a note that this NHC area of interest is out in the open Atlantic near the Azores. It’s not the current extratropical cyclone Xavier that is intensifying right now into a major weather event in northern Europe.

I did find a neat graphic on Xavier – note the large vectors for winds today, also that this low is centered in the North Sea/Sweden/Baltic Sea area, far from our potential subtropical storm:
 
images.aspx
 
The whole animated GIF is here. It’s time dependent.

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Something interesting’s going on out there. Will update later today.

New Storm

ZCZC MIATWOAT ALL
TTAA00 KNHC DDHHMM

SPECIAL TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
1250 PM EST WED DEC 4 2013

FOR THE NORTH ATLANTIC…CARIBBEAN SEA AND THE GULF OF MEXICO…

1. SHOWERS AND THUNDERSTORMS HAVE INCREASED IN ASSOCIATION WITH A
NON-TROPICAL LOW CENTERED ABOUT 450 MILES SOUTH OF THE AZORES
ISLANDS. THE LOW IS PRODUCING WINDS OF NEAR 60 MPH…AND SOME
ADDITIONAL DEVELOPMENT OF THIS SYSTEM IS POSSIBLE DURING THE NEXT
DAY OR SO BEFORE IT IS AFFECTED BY STRONG UPPER-LEVEL WINDS AND
MOVES OVER COLDER WATER. THIS SYSTEM HAS A LOW CHANCE…20
PERCENT…OF BECOMING A SUBTROPICAL OR TROPICAL CYCLONE DURING THE
NEXT 48 HOURS…AND A LOW CHANCE…20 PERCENT… OF BECOMING A
SUBTROPICAL OR TROPICAL CYCLONE DURING THE NEXT FIVE DAYS.

ADDITIONAL INFORMATION ON THIS SYSTEM CAN BE FOUND IN HIGH SEAS
FORECASTS ISSUED BY METEO FRANCE. ANOTHER SPECIAL TROPICAL WEATHER
OUTLOOK ON THIS SYSTEM WILL BE ISSUED NEAR 1 PM EST THURSDAY
DECEMBER 5…OR SOONER IF NECESSARY.

HIGH SEAS FORECASTS ISSUED BY METEO FRANCE CAN BE FOUND UNDER WMO
HEADER FQNT50 LFPW.

The GFS shows is interacting soon with the weather system that appears as a line of clouds to the west:

Either that, or Nature is trying to draw a meme.  (Image source)

Either that, or Nature is trying to draw a meme. (Image source)



Categories: Weather

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