Wilma's East Coast threat again increasing

[btangy]

00Z models are showing an increasing threat to the East coasts from extratropical Wilma + huge trough over the Ohio Valley. The 18Z GFS was showing landfall over Cape Cod, but its short term motion was suspect (landfall near Tampa) and its ensemble members were mostly off toward the E. The 00Z GFS has better short term motion and subsequently takes Wilma farther toward the E in the long run. However, it makes Wilma a strong extratropical low racing off toward the NNE with a very close pass to Cape Cod and Nantucket:

http://www.nco.ncep.noaa.gov/pmb/nwprod ... n_066m.gif

The 00Z NOGAPS has shifted much further W and is similar to the GFS, albeit a bit slower:

https://www.fnmoc.navy.mil/CGI/PUBLIC/w ... rp&tau=072

I have viewed the other 00Z model output, but I'm thinking there might be a similar shift with the consensus. The GFDL is usually very close to the GFS track.

The reason for the shift tonight is how the models are handling this very deep trough over the Ohio Valley in the coming days. For this I use the NAM for the evolution of the trough. The NOGAPS shows a similar shift from 12Z to 00Z. From the 12Z NAM at 72 hours, it shows a very deep, positively tilted trough with an axis stretching from PA to New England:

http://www.nco.ncep.noaa.gov/pmb/nwprod ... 0_072m.gif

Now the 00Z NAM at 60 hours shows an even deeper trough that's less positively tilted with an axis that's farther W. The vort max over Ohio marked by the 'x' agrees with the GFS 500mb forecast. Note the GFS is even less positively tilted and even stronger.

http://www.nco.ncep.noaa.gov/pmb/nwprod ... 0_060m.gif

http://www.nco.ncep.noaa.gov/pmb/nwprod ... 0_060m.gif

The result of all this is Wilma doesn't get pushed out to sea a comfortable distance from the East Coast and rain and wind all the way up and down the East Coast, though nothing like what FL will see. If this verifies, this may present a very quick but potent period of rough weather for many people much like a bad Nor'Easter. 2 inches of rain in New England may severely aggravate the flooding situation after tonight's inch of rain.

http://www.nco.ncep.noaa.gov/pmb/nwprod ... 8_078m.gif

Just got a look at the 00Z Canadian. It's also shifted significantly W from yesterday's 00Z run.

http://moe.met.fsu.edu/cgi-bin/cmctc2.c ... hour=072hr

EDIT:

00Z UKMET also in agreement. Yikes!

http://moe.met.fsu.edu/cgi-bin/ukmtc2.c ... hour=066hr

[aerojad]

That Canadian 72hr model run would be one heck of a hurricane/nor 'easter for New England... and it looks like that baby would be making a charge straight for Halifax.

[floridahurricaneguy]

having hard time understanding all this. So has GFS shifted south from earlier more in concensus with others or north towards Tampa/sarasota.

Sorry
Matt

[jkt21787]

having hard time understanding all this. So has GFS shifted south from earlier more in concensus with others or north towards Tampa/sarasota.

Sorry
Matt

His post has nothing to do with FL. It has to do with the East Coast/Northeast/New England.

FWIW, GFS shifted just slightly south at 00z. Only LBAR is the Tampa holdout. I certainly wouldn't be forecasting that track right now...

[floridahurricaneguy]

having hard time understanding all this. So has GFS shifted south from earlier more in concensus with others or north towards Tampa/sarasota.

Sorry
Matt

His post has nothing to do with FL. It has to do with the East Coast/Northeast/New England.

FWIW, GFS shifted just slightly south at 00z. Only LBAR is the Tampa holdout. I certainly wouldn't be forecasting that track right now...

No I wouldnt expect tampa at all. I just wondered if GFS shifted at all. Still interesting GFS is the northern most. Cant rule it out yet because we all know how the storms can wobble and jump. lol

Matt

[btangy]

having hard time understanding all this. So has GFS shifted south from earlier more in concensus with others or north towards Tampa/sarasota.
Matt

Sorry, I should have been more clear on this. The 18Z was an outlier compared to the other models and showed landfall near Tampa. The latest 00Z model shows landfall a little further south near Port Charlotte, which is still a little N of the NHC track, but more believable (relative to the avg of the other models).

Anytime a model doesn't get the short term motion correct, you don't expect the long term motion to be accurate, so with the GFS as an outlier in the short term, it was also an outlier in the long term (landfall over Cape Cod). Now that the 00Z GFS has come more into the consensus, its long term solution is more trustworthy.

But, that was not the point of my post. Rather, I was showing a key shift with how the models are handing the evolution of the trough over the Ohio Valley, and how this shift has major consequences on Wilma's track. All the 00Z models I've seen tonight show a bad Nor'Easter coming up the coast because they show the trough digging a little deeper, setting up a little farther W, and having less positive tilt.

[jkt21787]

having hard time understanding all this. So has GFS shifted south from earlier more in concensus with others or north towards Tampa/sarasota.

Sorry
Matt

His post has nothing to do with FL. It has to do with the East Coast/Northeast/New England.

FWIW, GFS shifted just slightly south at 00z. Only LBAR is the Tampa holdout. I certainly wouldn't be forecasting that track right now...

No I wouldnt expect tampa at all. I just wondered if GFS shifted at all. Still interesting GFS is the northern most. Cant rule it out yet because we all know how the storms can wobble and jump. lol

Matt

The GFS ensembles were further south than the OP GFS in earlier runs, and the ensembles usually outperform the operational model. I'm still thinking Fort Myers, but maybe as far north as Charlotte County or extreme southern Sarasota County.

[floridahurricaneguy]

having hard time understanding all this. So has GFS shifted south from earlier more in concensus with others or north towards Tampa/sarasota.

Sorry
Matt

His post has nothing to do with FL. It has to do with the East Coast/Northeast/New England.

FWIW, GFS shifted just slightly south at 00z. Only LBAR is the Tampa holdout. I certainly wouldn't be forecasting that track right now...

No I wouldnt expect tampa at all. I just wondered if GFS shifted at all. Still interesting GFS is the northern most. Cant rule it out yet because we all know how the storms can wobble and jump. lol

Matt

The GFS ensembles were further south than the OP GFS in earlier runs, and the ensembles usually outperform the operational model. I'm still thinking Fort Myers, but maybe as far north as Charlotte County or extreme southern Sarasota County.

So you would have it north of NHC track? I believe its deffinitely possible but what is some of your reasoning? j/w

Matt

[pgoss11]

6z GFDL has shifted south with it's landfall in Florida. How do you think this all pans out for the rest of the east coast? Does Wilma head north east off the coast and out to sea or does the less positively tilted trough pull her more north. Opinions?

Patty

[btangy]

6z GFDL has shifted south with it's landfall in Florida. How do you think this all pans out for the rest of the east coast? Does Wilma head north east off the coast and out to sea or does the less positively tilted trough pull her more north. Opinions?

Patty

06Z has shifted S and hence its long term motion is slightly further off the coast, but still close enough to bring nasty weather up and down the East Coast.

12Z NAM is coming in, and at 48 hours, it shows a slightly stronger trough with less positive tilt compared with the 00Z at 60 hours.

12Z 200mb heights and winds @ 48 hours:

http://www.nco.ncep.noaa.gov/pmb/nwprod ... 0_048m.gif

500mb heights and winds:

http://www.nco.ncep.noaa.gov/pmb/nwprod ... 0_048m.gif

00Z 200mb heights and winds @ 60 hours:

http://www.nco.ncep.noaa.gov/pmb/nwprod ... 0_060m.gif

500mb heights and winds:

http://www.nco.ncep.noaa.gov/pmb/nwprod ... 0_060m.gif

This may seem like a subtlety, but the tilt of the trough has major implications in how far N Wilma gets drawn and since it'll be moving at 40 knots, a slight change in the upper level pattern could mean a difference of 100 miles in the track off New England. A positively tilted trough would push Wilma farther out to sea and conversely with a negatively tilted trough.

The NAM has an interesting scenario with cyclogenesis off the Mid-Atlantic which then absorbes both Wilma and Alpha.

[pgoss11]

Thanks btangy; BTW I'm in RI so I'm watching closely. Worried about the water deluge. The ground can't take too much more right now. Even last nights rain has renewed some flooding.

Patty

[btangy]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAUNTON MA
132 PM EDT SUN OCT 23 2005

...HURRICANE WILMA WILL TRANSITION INTO A DANGEROUS OCEAN STORM BRINGING THE POTENTIAL FOR STRONG DAMAGING WINDS, HEAVY RAINS AND COASTAL FLOODING...

WILMA WILL TRANSITION INTO AN EXTREMELY POWERFUL OCEAN STORM HAVING CHARACTERISTICS THAT ARE PARTIALLY TROPICAL/EXTRA-TROPICAL. THE CANADIAN/UKMET/GFS/ECMWF ARE ALL SHOWING A LOW BETWEEN 970 AND 980 MB JUST SOUTHEAST OF
NANTUCKET AT TUESDAY 12Z. MEANWHILE OVER SOUTHEAST CANADA THERE IS A 1030 MB HIGH. THEREFORE...EXPECTING AN INCREDIBLE PRESSURE GRADIENT TO DEVELOP AND THE MEDIUM RANGE MODELS ARE DEPICTING 70 KNOTS OF WIND AT 850 MB OUT OF THE NORTHEAST. THEREFORE...WILL BE ISSUING A HIGH WIND WATCH FOR THE COASTAL LOCATIONS VERY LATE MONDAY NIGHT AND TUESDAY FOR NORTHEAST WINDS OF 30 TO 40 MPH WITH GUSTS TO 60 MPH.

RAINFALL AMOUNTS OF 2 TO 3 INCHES MAY FALL IN JUST 12 TO 18 HOUR WITH ISOLATED HEAVIER AMOUNTS POSSIBLE ACROSS THE HIGHER TERRAIN AND ALONG THE COAST BECAUSE OF LAND AND SEA CONVERGENCE.

DESPITE AN ASTRONOMICAL HIGH TIDE OF ONLY 8.9 FEET VERY STRONG NORTHEAST WINDS AND SEAS POSSIBLY BUILDING OVER 20 FEET WE MAY SEE OVER A 3 FOOT STORM SURGE. IF THIS OCCURS MODERATE COASTAL FLOODING WILL OCCUR.

OTHERWISE...RAIN MAY END AS SOME WET SNOW ACROSS PARTS OF THE INTERIOR TUESDAY NIGHT AND LINGER INTO WEDNESDAY MORNING.