ATL : TROPICAL DEPRESSION IDA

[Aric Dunn]

A comparison not to be underestimated in impact....Irene did about $1 billion (in 2009 adjusted $) in damage in florida and killed 15 (direct + indirect fatalities).

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I respectfully disagree with the posts which state "no shear" over Ida. it's pretty clear to see in both IR and Watervaopr imagery that there is indeed a modest to moderate amount of southerly shear pushing across the top of the system. Derived watervapor winds show southerly flow of about 15 knots over Honduras/Nicaragua punching into the system, and the shear increases steadily with latitude to where SW winds of 25-35 knots are over the Yucatan Channel, and these increase to 35-45 knots over western Cuba. You can see that outflow to the south of the system is nil.

That having been said, the shear appears to be strongly divergent, which will vent the convection pretty nicely, and, coupled with the fact that the magnitude of shear is not prohibitive, this should allow Ida to intensify over the northwest Caribbean. But given the fact that shear is only going to get steadliy less conducive and eventually hostile from here on out, the potential for Ida to become much more than a strong TS to borderline Cat 1 hurricane is quite low. JMHO...

I agree with you as i have mentioned the highly divergent flow. however after 60 to 72 hours most models develop a improving upper environment not great but still highly divergent... I would not go as far to say that for sure it will become less conducive as most guidance does not say that.. either way i still dont see much more than minimal hurricane at best.. at least right now anyway.. something similar to Irene in 1999

I did not mean the track by the way... just intensity.. the upper set up is very similar..

[wzrgirl1]

The last advisory put Ida in Hebert box #2. When will the next advisory be?

[SouthFLTropics]

A comparison not to be underestimated in impact....Irene did about $1 billion (in 2009 adjusted $) in damage in florida and killed 15 (direct + indirect fatalities).

I respectfully disagree with the posts which state "no shear" over Ida. it's pretty clear to see in both IR and Watervaopr imagery that there is indeed a modest to moderate amount of southerly shear pushing across the top of the system. Derived watervapor winds show southerly flow of about 15 knots over Honduras/Nicaragua punching into the system, and the shear increases steadily with latitude to where SW winds of 25-35 knots are over the Yucatan Channel, and these increase to 35-45 knots over western Cuba. You can see that outflow to the south of the system is nil.

That having been said, the shear appears to be strongly divergent, which will vent the convection pretty nicely, and, coupled with the fact that the magnitude of shear is not prohibitive, this should allow Ida to intensify over the northwest Caribbean. But given the fact that shear is only going to get steadliy less conducive and eventually hostile from here on out, the potential for Ida to become much more than a strong TS to borderline Cat 1 hurricane is quite low. JMHO...

I agree with you as i have mentioned the highly divergent flow. however after 60 to 72 hours most models develop a improving upper environment not great but still highly divergent... I would not go as far to say that for sure it will become less conducive as most guidance does not say that.. either way i still dont see much more than minimal hurricane at best.. at least right now anyway.. something similar to Irene in 1999

In addition to this Irene snuck up on us here in SE Florida. The NHC gets it right 99.9% of the time but on Irene the forecast and the advance warning was a bust. The forecast kept calling for her to go up the West Coast and instead she came right up through the bottom and out the East Coast near us here on the Treasure Coast. I was at a high school football game the night she came up and I remember there being torrential rain and then later that night we lost power the entire night. Definitely was a sneak attack!!!

SFT

[Evil Jeremy]

Contrary to the best track, I believe that this is now a TS and should be treated as such by the NHC at the end of the hour. Oh, and TS watches for the Yucatan seem possible within the next 1-2 advisories.

[CourierPR]

Contrary to the best track, I believe that this is now a TS and should be treated as such by the NHC at the end of the hour. Oh, and TS watches for the Yucatan seem possible within the next 1-2 advisories.

and Western Cuba

[Derek Ortt]

The warnings for Irene were not a complete bust

while a Hurricane Warning for DADE may have been appropriate, Irene only brought TS winds to the rest of Florida.

There was a TS Warning and a Hurricane Watch in effect. That and Katrina were just two cases where the warnings were not exactly followed that closely

[Derek Ortt]

http://manati.orbit.nesdis.noaa.gov/dat ... MBds76.png

latest QS is inconclusive as to whether or not this has ebcome a TS again

[Aric Dunn]

Contrary to the best track, I believe that this is now a TS and should be treated as such by the NHC at the end of the hour. Oh, and TS watches for the Yucatan seem possible within the next 1-2 advisories.

well watches should go yep here at 10.. it is likely that TS conditions are present as the buoy to its east earlier had one minute average winds of 34kts..

[SouthFLTropics]

The warnings for Irene were not a complete bust

while a Hurricane Warning for DADE may have been appropriate, Irene only brought TS winds to the rest of Florida.

There was a TS Warning and a Hurricane Watch in effect. That and Katrina were just two cases where the warnings were not exactly followed that closely

I'm sorry Derek but I don't recall a TS Warning all the way up on the Treasure Coast region...Although it has been 10 years and I could be mistaken. If one was issued I believe that it came way late in the game. I will do a little research and check the archives. If I'm wrong I'll eat crow but I remember at the time the "lack of warning" was a big deal with local officials.

SFT

[SouthFLTropics]

The warnings for Irene were not a complete bust

while a Hurricane Warning for DADE may have been appropriate, Irene only brought TS winds to the rest of Florida.

There was a TS Warning and a Hurricane Watch in effect. That and Katrina were just two cases where the warnings were not exactly followed that closely

I'm sorry Derek but I don't recall a TS Warning all the way up on the Treasure Coast region...Although it has been 10 years and I could be mistaken. If one was issued I believe that it came way late in the game. I will do a little research and check the archives. If I'm wrong I'll eat crow but I remember at the time the "lack of warning" was a big deal with local officials.

SFT

I stand corrected...The following comments and table comes from The NHC Website...I'll take my crow medium rare please!!!

Forecast and Warning Critique
The average official track errors during Irene's life as a tropical storm or hurricane were 54 n mi at 12 hours (21 cases), 92 n mi at 24 hours (19 cases), 104 n mi at 36 hours (17 cases), 127 n mi at 48 hours (15 cases) and 221 n mi at 72 hours (11 cases). With the exception of the 12- to 24-hour forecasts, these errors are lower than the previous 10-year averages of the official track errors. These 10-year average errors are 48, 89, 128, 164 and 242 n mi for 12, 24 ,36, 48 and 72 hours, respectively.

Table 3 lists the numerous watches and warnings issued. Some residents of southeast Florida expressed displeasure with the NWS forecasts. Although a tropical storm warning was issued for a portion of southeast Florida (meaning sustained winds between 39 and 73 mph) as indicated in Table 3, and torrential rains of 10 to 20 inches with locally higher amounts were forecast, some residents, especially in southeast Florida claimed that such conditions were "unexpected" or "surprising". There is an apparent disconnect between an accurate forecast issued some 36 hours in advance and a public perception of "surprise". The remedial challenge in this case appears to be related to communications and not to the forecast. The combined resources of NWS, the emergency management community and the local media apparently did not adequately convey the message to the public that: (a) track forecasts are not exact; (b) hurricanes are not a point but cover a broad area; and (c) serious effects usually extend for hundreds of miles from the center. Instead, some residents, as well as isolated TV reporting, focused on the center of Irene.

Indeed, the center of Irene was forecast to move along the west coast of Florida as indicated by most of the reliable and state-of-the-art track models shown in Fig. 4a. Instead, the center of Irene kept moving toward the north-northeast. The NHC nevertheless factored uncertainties into its forecast advisories and issued warnings appropriately as shown in Fig. 4b


Table 3. Tropical Cyclone watch and warning summary for Hurricane Irene Date/Time
(UTC) Action Location
13/1500 Tropical Storm Warning Cayman Islands.
13/1500 Hurricane Watch Cuban provinces of Pinar del Río, Havana, Ciudad Havana and Isle of Youth.
13/2100 Hurricane Warning Cuban provinces of Pinar del Río, Havana, Ciudad Havana, Matanzas and Isle of Youth.
13/2100 Hurricane Watch Lower and Middle Florida Keys, West of Craig Key including Dry Tortugas.
14/1200 Tropical Storm Warning Discontinued for Cayman Islands.
14/1500 Hurricane Warning Dry Tortugas.
14/1500 Hurricane Watch West coast of Florida from Flamingo to Boca Grande.
14/1500 Tropical Storm Warning Lower and Middle Florida Keys, West of Craig Key.
14/2100 Hurricane Warning South of Florida City around the Florida peninsula to Boca Grande, including all Florida Keys and Dry Tortugas
14/2100 Tropical Storm Warning and Hurricane Watch From Florida City to Jupiter Inlet and Lake Okeechobee.
14/2100 Hurricane Watch North of Boca Grande to Longboat Key.
15/0300 Hurricane Warning Extended Northward along Florida West Coast to Anclote Keys.
15/0300 Hurricane Watch From North of Anclote Keys to Yankeetown
15/0300 Hurricane Warning Discontinued for Cuban provinces of Pinar del Río, Matanzas and Isle of Youth.
15/0900 Tropical Storm Warning and Hurricane Watch Extended Northward along Florida East coast to South of Flagler Beach.
15/0900 Hurricane Warning Discontinued for all Cuban provinces
15/1200 Tropical Storm Watch Bimini, Grand Bahama and Abaco Islands in Bahamas.
15/2100 Tropical Storm Warning (Downgraded from Hurricane Warning) North of Bonita Beach to the Anclote Keys.
15/2100 Tropical Storm Warning Extended Northward from Florida City to Fernandina Beach and Lake Okeechobee.
15/2100 Tropical Storm Watch North of Fernandina Beach to Savannah, Georgia.
15/2100 Hurricane Watch All discontinued.
16/0300 All Warnings Discontinued South of Florida City, the Florida Keys, the Dry Tortugas and the Florida West coast.
16/0300 Tropical Storm Watch Extended Northward from North of Fernandina Beach to Little River Inlet, South Carolina.
16/0300 Tropical Storm Watch Discontinued for Abaco Islands, Bahamas.
16/0900 Tropical Storm Warning Extended North of Fernandina Beach, Florida to Edisto Beach, South Carolina.
16/0900 Hurricane Watch North of Edisto Beach to Cape Hatteras, North Carolina including Pamlico Sound.
16/0900 Tropical Storm Warning Discontinued along the Florida East coast from Jupiter Inlet Southward, including Lake Okeechobee.
16/1500 Hurricane Warning From Edisto Beach, South Carolina to Surf City, North Carolina.
16/1500 Tropical Storm Watch Discontinued for Bimini and Grand Bahama Island.
16/2100 Hurricane Warning Expanded from Savannah, Georgia to Cape Hatteras, North Carolina including Pamlico Sound
16/2100 Hurricane Watch North of Cape Hatteras to the North Carolina/Virginia border, including Albemarle Sound.
16/2100 Tropical Storm Warning Discontinued South of Vero Beach, Florida.
17/0300 Tropical Storm Warning(Replacing Hurricane Watch) North of Cape Hatteras to the North Carolina/Virginia border, including Albemarle Sound.
17/0300 Tropical Storm Warning Discontinued South of New Smyrna Beach, Florida.
17/0900 Tropical Storm Warning Discontinued South of St. Augustine Beach, Florida.
17/1500 Tropical Storm Warning Discontinued South of Fernandina Beach, Florida.
17/2100 All Warnings Discontinued from Edisto Beach, South Carolina Southward.
18/0000 Hurricane Warning Discontinued South of Santee River, South Carolina.
18/0300 All Warnings Discontinued from Surf City, North Carolina Southward.
18/0300 Tropical Storm Warning (downgraded from Hurricane Warning) North of Surf City, North Carolina to North Carolina/Virginia border, including Pamlico and Albemarle Sounds.
18/0600 All Warnings Discontinued from Bogue Inlet, North Carolina Southward.
18/0900 All Warnings Discontinued everywhere they had still been in effect.


*Tropical Cyclone watches and warnings are issued by respectively countries in coordination with the National Hurricane Center

[AJC3]

The warnings for Irene were not a complete bust

while a Hurricane Warning for DADE may have been appropriate, Irene only brought TS winds to the rest of Florida.

There was a TS Warning and a Hurricane Watch in effect. That and Katrina were just two cases where the warnings were not exactly followed that closely

I'm sorry Derek but I don't recall a TS Warning all the way up on the Treasure Coast region...Although it has been 10 years and I could be mistaken. If one was issued I believe that it came way late in the game. I will do a little research and check the archives. If I'm wrong I'll eat crow but I remember at the time the "lack of warning" was a big deal with local officials.

SFT

You're in our CWA. A TS warning and Hurricane Watch went up at 5 AM on the 15th from Jupiter Inlet north to Flagler Beach. Irene's center was still down at 24N and 81.5W at the time.

[SouthFLTropics]

The warnings for Irene were not a complete bust

while a Hurricane Warning for DADE may have been appropriate, Irene only brought TS winds to the rest of Florida.

There was a TS Warning and a Hurricane Watch in effect. That and Katrina were just two cases where the warnings were not exactly followed that closely

I'm sorry Derek but I don't recall a TS Warning all the way up on the Treasure Coast region...Although it has been 10 years and I could be mistaken. If one was issued I believe that it came way late in the game. I will do a little research and check the archives. If I'm wrong I'll eat crow but I remember at the time the "lack of warning" was a big deal with local officials.

SFT

You're in our CWA. A TS warning and Hurricane Watch went up at 5 AM on the 15th from Jupiter Inlet north to Flagler Beach. Irene's center was still down at 24N and 81.5W at the time.

Yes, I agree...I checked the NHC Website and I stand corrected...Please see my previous post...

[CrazyC83]

http://manati.orbit.nesdis.noaa.gov/dataimages21/cur_hires/zooms/WMBds76.png

latest QS is inconclusive as to whether or not this has ebcome a TS again

I see several uncontaminated brown barbs in there (35 - 40 kt) and a purple barb (40 - 45 kt) but well removed from the centre and likely not representative.

[Derek Ortt]

Those looks very near the rain contamination and I am not sure if the auto rain flagging missed those vectors or not

[Blown Away]

November tracks.

[ozonepete]

I respectfully disagree with the posts which state "no shear" over Ida. it's pretty clear to see in both IR and Watervaopr imagery that there is indeed a modest to moderate amount of southerly shear pushing across the top of the system. Derived watervapor winds show southerly flow of about 15 knots over Honduras/Nicaragua punching into the system, and the shear increases steadily with latitude to where SW winds of 25-35 knots are over the Yucatan Channel, and these increase to 35-45 knots over western Cuba. You can see that outflow to the south of the system is nil.

That having been said, the shear appears to be strongly divergent, which will vent the convection pretty nicely, and, coupled with the fact that the magnitude of shear is not prohibitive, this should allow Ida to intensify over the northwest Caribbean. But given the fact that shear is only going to get steadliy less conducive and eventually hostile from here on out, the potential for Ida to become much more than a strong TS to borderline Cat 1 hurricane is quite low. JMHO...

Hey thanks for the important comments, AJC3. I also disagree with posts that say no shear. I think in my post I should have said there's no deleterious effects of that shear so far instead of no effects. Thanks for catching it and clarifying that.

As far as the shear steadily getting worse, that's not the way the forecasts are trending. Here's a combination of the GFS shear forecast from this morning's 12Z run. It shows the shear forecast for 08/0000 08/1200 09/0000 09/1200 10/0000 10/120000 and it shows the shear relaxing ahead of Ida as it moves north between now and Tuesday. That makes sense of course if the subtropical/polar boundary keeps moving northward as a Bermuda high gets established over the east coast for the next few days. And if that pans out, it's a very different ballgame.

[SouthFLTropics]

November tracks.

Well that narrows it down!!! LOL

[cycloneye]

TROPICAL DEPRESSION IDA ADVISORY NUMBER 11
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL112009
1000 PM EST FRI NOV 06 2009

...IDA MOVING NORTHWARD AWAY FROM HONDURAS...COULD BECOME A TROPICAL
STORM SOON...

INTERESTS IN THE CAYMAN ISLANDS...THE YUCATAN PENINSULA OF MEXICO
AND WESTERN CUBA SHOULD MONITOR THE PROGRESS OF IDA.

FOR STORM INFORMATION SPECIFIC TO YOUR AREA...PLEASE MONITOR
PRODUCTS ISSUED BY YOUR NATIONAL METEOROLOGICAL SERVICE.

AT 1000 PM EST...0300 UTC...THE CENTER OF TROPICAL DEPRESSION IDA
WAS LOCATED NEAR LATITUDE 16.2 NORTH...LONGITUDE 84.0 WEST OR ABOUT
110 MILES...175 KM...EAST-NORTHEAST OF LIMON HONDURAS.

THE DEPRESSION IS MOVING TOWARD THE NORTH NEAR 7 MPH...11 KM/HR.
THIS GENERAL MOTION IS EXPECTED TO CONTINUE TONIGHT WITH A TURN
TOWARD THE NORTH-NORTHWEST ON SATURDAY. ON THIS TRACK...IDA IS
FORECAST TO APPROACH THE YUCATAN CHANNEL LATE SUNDAY.

MAXIMUM SUSTAINED WINDS ARE NEAR 35 MPH...55 KM/HR...WITH HIGHER
GUSTS. SOME STRENGTHENING IS FORECAST DURING THE NEXT 48 HOURS...
AND IDA COULD BECOME A TROPICAL STORM TONIGHT OR ON SATURDAY.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 1006 MB...29.71 INCHES.

THE RAINFALL THREAT ASSOCIATED WITH IDA IS DIMINISHING OVER
NORTHEASTERN HONDURAS...WHERE ADDITIONAL RAINFALL AMOUNTS OF 1 TO 2
INCHES ARE POSSIBLE. RAINFALL AMOUNTS OF 1 TO 2 INCHES ARE ALSO
POSSIBLE ACROSS THE CAYMAN ISLANDS.

...SUMMARY OF 1000 PM EST INFORMATION...
LOCATION...16.2N 84.0W
MAXIMUM SUSTAINED WINDS...35 MPH
PRESENT MOVEMENT...NORTH OR 360 DEGREES AT 7 MPH
MINIMUM CENTRAL PRESSURE...1006 MB

THE NEXT ADVISORY WILL BE ISSUED BY THE NATIONAL HURRICANE CENTER AT
400 AM EST.

$$
FORECASTER BERG/BROWN

000
WTNT41 KNHC 070233
TCDAT1
TROPICAL DEPRESSION IDA DISCUSSION NUMBER 11
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL112009
1000 PM EST FRI NOV 06 2009

A 2302 UTC SSMIS MICROWAVE PASS INDICATED THAT THE LOW-LEVEL CENTER
OF IDA WAS LOCATED JUST OFF THE NORTHEASTERN COAST OF HONDURAS AND
WAS DISPLACED TO THE SOUTH AND SOUTHEAST OF THE DEEP CONVECTION.
NEW CONVECTION IS DEVELOPING CLOSE TO THE CENTER...AND DVORAK
ESTIMATES FROM TAFB AND SAB ARE 25 KT AND 30 KT...RESPECTIVELY.
NOAA BUOY 42057...LOCATED ABOUT 150 N MI EAST-NORTHEAST OF THE
CENTER...RECENTLY REPORTED A 1-MINUTE SUSTAINED WIND OF 35 KT...BUT
IT APPEARS THAT THIS OCCURRED WITH THE PASSAGE OF A SQUALL AND MAY
NOT BE REPRESENTATIVE OF THE OVERALL CIRCULATION. THEREFORE...IDA
IS KEPT AS A TROPICAL DEPRESSION FOR THIS ADVISORY...BUT IT IS
PROBABLY VERY CLOSE TO REGAINING TROPICAL STORM STATUS.

IDA CONTINUES TO MOVE NORTHWARD AT 360/6. A MID-LEVEL ANTICYCLONE
BETWEEN JAMAICA AND HISPANIOLA AND A DEEP-LAYER TROUGH OVER MEXICO
ARE EXPECTED TO STEER IDA NORTH-NORTHWESTWARD THROUGH THE NEXT 72
HOURS. THE TRACK GUIDANCE IS IN GOOD AGREEMENT DURING THIS PERIOD
ALTHOUGH THE GFDL AND HWRF MODELS ARE THE EASTERNMOST MODELS AND
HAVE FORCED THE MODEL CONSENSUS A LITTLE MORE TO THE EAST. THE
FORECAST BEYOND 72 HOURS IS STILL COMPLEX AND IS DEPENDENT ON HOW
IDA INTERACTS WITH THE FRONT AND SHORTWAVE TROUGH OVER THE GULF OF
MEXICO. MOST OF THE GUIDANCE SHOWS IDA BECOMING EXTRATROPICAL BY
96 HOURS ONCE IT MERGES WITH THE FRONT...BUT THE SOLUTIONS VARY ON
WHERE THE LOW GOES NEXT. ONLY THE 1200 UTC ECMWF AND UKMET SHOW
IDA BECOMING PICKED UP BY A SHORTWAVE TROUGH AND MOVING
NORTHEASTWARD OVER THE NORTHERN GULF. THE OTHER MODELS INDICATE A
MORE PRONOUNCED SOUTHWARD MOTION AFTER 96 HOURS...AND THE OFFICIAL
FORECAST NOW SHOWS A SLOW SOUTHEASTWARD TURN AT 120 HOURS.

ALTHOUGH WATERS ARE WARM OVER THE NORTHWESTERN CARIBBEAN...VERTICAL
SHEAR IS EXPECTED TO HAMPER MUCH INTENSIFICATION OVER THE NEXT FEW
DAYS. THE GFDL AND HWRF MAKE IDA A HURRICANE OVER THE CENTRAL GULF
OF MEXICO...A SCENARIO THAT DOES NOT SEEM PLAUSIBLE IN THE FACE OF
WESTERLY SHEAR THAT IS EXPECTED TO INCREASE TO 50 OR 60 KT BY DAY
4. THE OFFICIAL FORECAST INDICATES SOME SLOW STRENGTHENING OVER
THE NEXT SEVERAL DAYS BUT PEAKS THE INTENSITY AT 45 KT...WHICH IS
JUST BELOW THE INTENSITY CONSENSUS.

IT IS OF NOTE THAT MOST OF THE GLOBAL MODELS ARE SHOWING A LARGE
PRESSURE GRADIENT BETWEEN A HIGH OVER THE SOUTHEASTERN UNITED
STATES AND THE TROPICAL CYCLONE. THIS COULD CONTRIBUTE TO A LARGE
AREA OF STRONG WINDS OVER THE GULF OF MEXICO NOT DIRECTLY
ATTRIBUTABLE TO IDA.

FORECAST POSITIONS AND MAX WINDS

INITIAL 07/0300Z 16.2N 84.0W 30 KT
12HR VT 07/1200Z 17.1N 84.2W 35 KT
24HR VT 08/0000Z 18.4N 84.8W 35 KT
36HR VT 08/1200Z 19.7N 85.5W 40 KT
48HR VT 09/0000Z 21.4N 86.5W 45 KT
72HR VT 10/0000Z 25.5N 88.0W 45 KT
96HR VT 11/0000Z 27.5N 87.0W 45 KT...EXTRATROPICAL
120HR VT 12/0000Z 26.5N 85.6W 35 KT...EXTRATROPICAL

$$
FORECASTER BERG

[cycloneye]

...SUMMARY OF 1000 PM EST INFORMATION...
LOCATION...16.2N 84.0W
MAXIMUM SUSTAINED WINDS...35 MPH
PRESENT MOVEMENT...NORTH OR 360 DEGREES AT 7 MPH
MINIMUM CENTRAL PRESSURE...1006 MB

[cycloneye]