ATL : TROPICAL DEPRESSION IDA

[Evil Jeremy]

It is more than likely my untrained eyes trying to find something interesting, but is it possible that the MLC and the LLC are decoupling?

http://www.ssd.noaa.gov/goes/flt/t2/loop-vis.html

[AdamFirst]

...SUMMARY OF 1000 AM EST INFORMATION...
LOCATION...15.0N 84.0W
MAXIMUM SUSTAINED WINDS...35 MPH
PRESENT MOVEMENT...NORTH OR 360 DEGREES AT 7 MPH
MINIMUM CENTRAL PRESSURE...1007 MB

[Evil Jeremy]

New advisory is out, and the NHC now expects Ida to be extra tropical in 5 days:

[ozonepete]

... snip...

Also, I still think anywhere from Pensacola to Sarasota. Too early to tell. But I am thinking a little more about Tampa now.

It would have to cross the jet core to hit Pensacola, so probably not that far west.

Yeah, I know, but I've been thinking that the coming 500mb trough might dig deeper into the central Gulf and slow down. That would open up a strong southerly flow rather than southwest flow in the eastern Gulf. It would also introduce the possibility of a hybrid developing (or of course a sheared mess). Anyway I'm waiting for the 12Z GFS and other runs to see how that aspect plays out.

[HURAKAN]

210
WTNT41 KNHC 061453
TCDAT1
TROPICAL DEPRESSION IDA DISCUSSION NUMBER 9
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL112009
1000 AM EST FRI NOV 06 2009

SATELLITE IMAGES INDICATE THAT BANDS OF THUNDERSTORMS CONTINUE TO
FORM IN THE NORTHERN SEMICIRCLE OF IDA...THOUGH SOMEWHAT REMOVED
FROM THE CENTER. NOAA BUOY 42057 SHOWED PEAK 1-MINUTE WINDS OF 29
KT EARLIER THIS MORNING...SO THE INITIAL INTENSITY WILL BE HELD AT
30 KT. IDA WILL HAVE AN OPPORTUNITY FOR SOME RESTRENGTHENING
OVERNIGHT AFTER IT EMERGES FROM EASTERN HONDURAS. THERE CONTINUES
TO BE A LARGE DISAGREEMENT AMONG THE MODELS ON HOW MUCH
INTENSIFICATION TO EXPECT WITH IDA. THE STATISTICAL GUIDANCE
GENERALLY SHOWS A RATHER MODEST AMOUNT OF RESTRENGTHENING...WHILE
THE REGIONAL HURRICANE MODELS SUGGEST THAT IDA WILL BECOME A
HURRICANE AGAIN. SINCE SHEAR IS FORECAST TO BE NEAR 20 KT OVER THE
NORTHWESTERN CARIBBEAN BY MOST OF THE GLOBAL MODELS...AND EVEN
HIGHER IN THE GULF OF MEXICO...THE NHC FORECAST WILL STAY MUCH
CLOSER TO THE STATISTICAL GUIDANCE. AT THE END OF PERIOD...SOME
WEAKENING IS SHOWN DUE TO SHEAR BECOMING STRONG AND COOLER WATERS
IN THE NORTHERN GULF OF MEXICO...WHICH WILL LIKELY START THE
EXTRATROPICAL TRANSITION OF IDA.

IDA HAS TURNED TOWARD THE NORTH...360/6. A WEAK MID-LEVEL RIDGE OVER
THE CENTRAL CARIBBEAN SEA IS FORECAST TO STEER THE STORM NORTHWARD
FOR THE NEXT DAY OR SO. THEREAFTER... IDA SHOULD TURN TOWARD THE
NORTH-NORTHWEST OR NORTHWEST AS SHORTWAVE RIDGING OVER THE
SOUTHEASTERN UNITED STATES BUILDS. IN THE LONG-RANGE...A TROUGH
OVER THE GULF OF MEXICO COULD FORCE IDA TO TURN TO THE NORTH OR
NORTHEAST. HOWEVER...THE INTERACTION OF IDA WITH THAT TROUGH IS
CAUSING A WIDE VARIETY OF MODEL SOLUTIONS... RANGING FROM A FASTER
CENTRAL GULF OF MEXICO LANDFALL TO IDA REMAINING SEPARATE FROM THE
TROUGH AND STAYING OVER THE CENTRAL GULF WATERS. ALTHOUGH SOME OF
THE MODELS HAVE SHIFTED WESTWARD SINCE THE LAST RUN...CLIMATOLOGY
AND THE FORECAST STRONG UPPER- LEVEL SOUTHWESTERLY WINDS SUGGEST
THE EASTERN SOLUTIONS ARE LIKELY CLOSER TO REALITY. THE NHC
FORECAST REMAINS CLOSE TO THE PREVIOUS ONE...AND ON THE EASTERN
SIDE OF THE GUIDANCE ENVELOPE.

THERE IS STILL A THREAT OF LIFE-THREATENING FLASH FLOODS AND MUD
SLIDES CAUSED BY EXTREMELY HEAVY RAIN OVER PORTIONS OF HONDURAS
TODAY.

FORECAST POSITIONS AND MAX WINDS

INITIAL 06/1500Z 15.0N 84.0W 30 KT
12HR VT 07/0000Z 15.7N 84.1W 30 KT...OVER WATER
24HR VT 07/1200Z 16.8N 84.5W 35 KT
36HR VT 08/0000Z 17.9N 85.1W 40 KT
48HR VT 08/1200Z 19.1N 85.8W 45 KT
72HR VT 09/1200Z 22.5N 87.5W 45 KT
96HR VT 10/1200Z 25.0N 87.5W 45 KT
120HR VT 11/1200Z 27.0N 86.0W 40 KT...EXTRATROPICAL

$$
FORECASTER BLAKE/FRANKLIN

[wxman57]

NHC track looks a bit odd in that they slow it down a good bit once it moves into stronger steering currents ahead of the cold front in the eastern Gulf. My final point on the 5 day track is 150 miles ENE of the NHC's.

[HURAKAN]

Non-tropical before potentially reaching Florida

[ericinmia]

I think the big difference in track and forecast is going to occur if this is able to ramp up to a Cat1-2. The current forecast doesn't plan on that, and we know how difficult it can be to forecast intensification...

If it were to make it to a Cat2 or so, that would have a bearing on future track and also what effects someone would feel down the line... (transitioning to ET before land may be premature in that scenario.)
-Eric

EDIT:
Also interesting to note is the somewhat recent NNE motion that seems to be aparent the for the past couple hours. That was something suggested by the GFDL a few runs back, and it will be interesting to see if that is a track change, or simply a wobble.

[Evil Jeremy]

I think a decent chunk of the future track and intensity of Ida relies on how much of a west bend it makes over the next 24 hours, and in extension the next couple of days. The track has been surprising in some ways so far. This time yesterday, Ida was not forecast to return to water until about 7 AM tomorrow, and now it looks like Ida will do so at least 12 hours sooner than that time.

[Bocadude85]

It is more than likely my untrained eyes trying to find something interesting, but is it possible that the MLC and the LLC are decoupling?

http://www.ssd.noaa.gov/goes/flt/t2/loop-vis.html

Ida looks to be moving a little E of due N

[wxman57]

If you read the discussion, the NHC is hedging its bet with the track in the Gulf. They do mention the stronger SW flow it's moving into and the likely scenario it'll move faster and be farther east than forecast.

[ozonepete]

NHC track looks a bit odd in that they slow it down a good bit once it moves into stronger steering currents ahead of the cold front in the eastern Gulf. My final point on the 5 day track is 150 miles ENE of the NHC's.

I think they're having trouble with that 500mb trough. As a matter of fact, I guess we all are, since it's the key to direction and strength, including when it becomes extratropical. I just saw the 12Z GFS output, and it has been progressively weakening the trough and cutting back on its southerly extent. If that pans out, steering could be signifcantly weaker and maybe that's why they're keeping Ida's speed slower. The 250 and 300mb wind speeds are also now forecast to be pretty lame (20 knots) at the forecast latitude for Tuesday 7AM (12Z).

[Aric Dunn]

Well as for the 5 day.. Its highly suspect .. first of all on its current track it should be over water later this afternoon but we have to remember that its essentially paralleling the coast and if it wabbles at anytime to the nne then it will be over water much sooner which again allows more time to strengthen. And if it does reach hurricane strength before entering the gulf then extra tropical transition is going to take quite a bit longer. of a more pressing matter if it does transition and slows down as some of the models say then the wind field will expand considerably which would be a problem for coastal flooding especially near the tampa area.. remember the super storm ?

[HURAKAN]

Loop

[gatorcane]

NAM shows a significant system in the NW Caribbean in 84 hours:

[gatorcane]

so when will it be back over water? Any guesses? Looks like NNE movement (wobble) now. GFDL/GFS forecasted this type of movement before NNW/NW movement takes place in a couple of days.

[AdamFirst]

Looks like she's about to emerge back over water, within the next few hours.

I notice low clouds beginning to stream around the LLC again, on the south side....this girl is hungry and the all-you-can-eat buffet is not that far away

[Steve H.]

Looks like she is mvoing a bit faster now, just north of the Honduras/Nicaragua border. I expect she will get back to TS status tonight as there is significant moisture, banding to her north.

[ozonepete]

Well as for the 5 day.. Its highly suspect .. first of all on its current track it should be over water later this afternoon but we have to remember that its essentially paralleling the coast and if it wabbles at anytime to the nne then it will be over water much sooner which again allows more time to strengthen. And if it does reach hurricane strength before entering the gulf then extra tropical transition is going to take quite a bit longer. of a more pressing matter if it does transition and slows down as some of the models say then the wind field will expand considerably which would be a problem for coastal flooding especially near the tampa area.. remember the super storm ?

Yup. If that trough does really dig deeper and the high vorticity area at its nose gets close to Ida, you could have a really powerful hybrid.

[Blown Away]

I'm seeing a decent NNE or NE wobble in past few frames. I still think the final track will be well right of the current track.
http://www.ssd.noaa.gov/goes/east/carb/loop-vis.html