ATL: ISAAC - Post-Tropical - Discussion

[BigB0882]

I don't think the NHC is just going with the Euro for the 11pm update. I think they also looked at what some of the models did at 18z.

[ObsessedMiami]

still no discussion on the NHC webpage!!!???

Ok, good it's not just me! I've been hitting refresh every few seconds thinking something was wrong!

They are speechless!

[stormgeek]

Really good lightning thunder rain here in north broward.

[brunota2003]

still no discussion on the NHC webpage!!!???

I think they are sitting there looking at that eye (that is still there in the 2:40 UTC imagery) going "um...so what should we do now?"

[hurricanes1234]

Yeah, the discussion isn't out yet.

[SunnyThoughts]

still no discussion on the NHC webpage!!!???

I think they are sitting there looking at that eye (that is still there in the 2:40 UTC imagery) going "um...so what should we do now?"

If its Stewart who is doing the writing..he loves to write catalogs ..which is awesome.

[cycloneye]

As soon it comes out,it will be at the Advisories thread.

[OzCycloneChaserTrav]

Pretty amazing to put into perspective. Isaac is probably now a Category 2 tropical cyclone on the Australian scale, nothing to be sneezed at !

[Bocadude85]

Winds howling here in Boca Raton right now... easily over tropical storm force right now.. probably gusting to 45mph

[maxx9512]

This is one of the latest disco's I've seen. Must be an interesting update. A lot for them to decide now and how to word it.

[CronkPSU]

actually kind of anti-climactic


000
WTNT44 KNHC 250319
TCDAT4

TROPICAL STORM ISAAC DISCUSSION NUMBER 16
NWS NATIONAL HURRICANE CENTER MIAMI FL AL092012
1100 PM EDT FRI AUG 24 2012

SATELLITE IMAGERY AND RECONNAISSANCE AIRCRAFT DATA INDICATE THAT THE
CIRCULATION AND CONVECTIVE ORGANIZATION OF ISAAC HAS CONTINUED TO
IMPROVE SINCE THE PREVIOUS ADVISORY. INFRARED AND MICROWAVE
SATELLITE IMAGERY SUGGEST THAT AN EYE IS FORMING...AND THIS IS THE
BASIS FOR INCREASING THE INTENSITY TO 60 KT.

THE INITIAL MOTION ESTIMATE IS 315/12 BASED ON RECON AND MICROWAVE
FIXES. ALTHOUGH THE TRACK FORCAST WAS ADJUSTED SLIGHTLY TO THE
RIGHT THROUGH 48 HOURS...NO OTHER SIGNIFICANT CHANGES WERE MADE TO
THE PREVIOUS ADVISORY TRACK. RECENT UPPER-AIR DATA AND NOAA G-IV
AIRCRAFT DROPSONDE DATA INDICATE THE TROUGH THAT HAS CREATED THE
BREAK IN THE SUBTROPICAL RIDGE ACROSS FLORIDA HAS SHIFTED TO A
POSITION JUST EAST OF THE FLORIDA PENINSULA. THE 18Z GFS MODEL...
WHICH SHIFTED TO THE RIGHT OF ITS 12Z TRACK...CAPTURED THIS FARTHER
EAST POSITION...WHEREAS THE 18Z UKMET AND 12Z ECMWF KEPT THE TROUGH
ACROSS THE WESTERN FLORIDA PENINSULA VALID AT 00Z THIS EVENING.
BASED ON THE GFS VERIFYING BETTER THAN THE OTHER MODELS AT 00Z THIS
EVENING...THE NHC TRACK HAS BEEN SHIFTED A LITTLE TO THE RIGHT.
AFTER 48 HOURS...THE RIDGE IS EXPECTED TO BUILD BACK WESTWARD
ACROSS FLORIDA AND KEEPING ISAAC ON A MOSTLY NORTHWESTWARD HEADING
ACROSS THE EASTERN AND NORTH-CENTRAL GULF MEXICO. THE OFFICIAL
FORECAST TRACK IS CLOSE TO THE CONSENSUS MODELS TVCA AND TV15
THROUGH 48 HOURS...AND THEN IS A LITTLE TO THE RIGHT OF THOSE
MODELS AFTER THAT.

WITH THE INNER CORE CONVECTION IMPROVING...THERE IS STILL THE
POSSIBILITY THAT ISAAC COULD REACH HURRICANE INTENSITY BEFORE
REACHING HAITI TONIGHT. THE INTENSITY FROM 12-24 HOURS WILL BE
DETERMINED BY THE AMOUNT OF LAND INTERACTION WITH HAITI AND EASTERN
CUBA. AFTER THAT...THE SLIGHT EASTWARD SHIFT IN THE FORECAST TRACK
IS ENOUGH TO PLACE ISAAC OVER WATER LONGER THAN WHAT WAS INDICATED
IN THE PREVIOUS INTENSITY FORECAST REQUIRED AN INCREASE IN THE
INTENSITY FORECAST. THE EASTWARD TRACK SHIFT AND A LARGER INITIAL
AND FORECAST WIND FIELD TO THE NORTH ARE WHAT NECESSITATED THE
CHANGES IN THE WATCHES AND WARNINGS FOR FLORIDA.

IT IS IMPORTANT NOT TO FOCUS ON THE EXACT TRACK DUE TO THE
UNCERTAINTIES IN THE FORECAST AND THE FACT THAT ISAAC HAS A LARGE
AREA OF TROPICAL-STORM-FORCE WINDS ASSOCIATED WITH IT.

FORECAST POSITIONS AND MAX WINDS

INIT 25/0300Z 17.7N 72.5W 60 KT 70 MPH
12H 25/1200Z 19.4N 74.1W 50 KT 60 MPH
24H 26/0000Z 21.7N 76.7W 50 KT 60 MPH
36H 26/1200Z 23.4N 79.4W 55 KT 65 MPH
48H 27/0000Z 24.9N 81.6W 60 KT 70 MPH
72H 28/0000Z 27.1N 84.6W 70 KT 80 MPH
96H 29/0000Z 30.0N 86.5W 80 KT 90 MPH
120H 30/0000Z 32.5N 86.5W 40 KT 45 MPH...INLAND

$$
FORECASTER STEWART

[Jevo]

If all else fails... Tweet to Dr. Knabb

@Grumpyhaus:
@NHCDirector 11PM Disco running a little late?

[ObsessedMiami]

Miami Met is saying on tv that the tropical storm warning for SFL is only for a narrow strip from I 95 to the Atlantic along the coast. Can this be right for a storm passing by to the west????

[summersquall]

Discussion out!

[Aric Dunn]

very good discussion ! interesting I did not pick up on the 18z gfs trough location but it does make sense now why it went more east through 48hrs.

[WxEnthus]

Just my opinion, but i think NHC should consider getting rid of the cone altogether. It confuses people... they think that the cone is the area that will receive affects... they don't understand the strike probability that the cone is supposed to convey. The closer you get to the storm, the smaller the cone gets, which many people mistakenly interpret to mean that they won't receive affects. Instead, they should show a band of expected wind speed coverage for the storm's passage so that people can see the actual width of a tropical cyclone. You see this band from time to time on some sites, but the cone is usually the graphic that gets the most coverage.

I like the fan-style circles that Wunderground uses -- they show the strength and distance of the wind field in each quadrant. That would work for a 48 hour track, not sure how to show that info in later track points as the error rate spreads to a considerable distance. The fan-style shows intensity pretty well for near-future forecasting but this becomes a problem the further out in time you go -- forecasting intensity is tricky at best and you can't have a giant fan looking like it's going to swallow Texas pr half the east coast at Day 5 just to cover the stretch of area that it may possibly be located at in five days.

[SunnyThoughts]

Awesome freakin discussion by Stacey STewart!!!

[ballred]

I've been a member for a long time, but do not think I have ever posted until now.

I have a question. If tropical storm force wings are predicted at 185 miles from the center of the storm, and it is predicted to go up the west coast of FL at least through Sunday, why haven't we seen TS watches go up further along the coast to this point? Is it just too early (i.e. outside of the 48 hour time frame)?

It would seem to reason that we should be seeing something at least as far north as Ft. Myers and Sarasota.

[MiamiensisWx]

THE INITIAL MOTION ESTIMATE IS 315/12 BASED ON RECON AND MICROWAVE
FIXES. ALTHOUGH THE TRACK FORCAST WAS ADJUSTED SLIGHTLY TO THE
RIGHT THROUGH 48 HOURS...NO OTHER SIGNIFICANT CHANGES WERE MADE TO
THE PREVIOUS ADVISORY TRACK. RECENT UPPER-AIR DATA AND NOAA G-IV
AIRCRAFT DROPSONDE DATA INDICATE THE TROUGH THAT HAS CREATED THE
BREAK IN THE SUBTROPICAL RIDGE ACROSS FLORIDA HAS SHIFTED TO A
POSITION JUST EAST OF THE FLORIDA PENINSULA. THE 18Z GFS MODEL...
WHICH SHIFTED TO THE RIGHT OF ITS 12Z TRACK...CAPTURED THIS FARTHER
EAST POSITION...WHEREAS THE 18Z UKMET AND 12Z ECMWF KEPT THE TROUGH
ACROSS THE WESTERN FLORIDA PENINSULA VALID AT 00Z THIS EVENING.
BASED ON THE GFS VERIFYING BETTER THAN THE OTHER MODELS AT 00Z THIS
EVENING...THE NHC TRACK HAS BEEN SHIFTED A LITTLE TO THE RIGHT.
AFTER 48 HOURS...THE RIDGE IS EXPECTED TO BUILD BACK WESTWARD
ACROSS FLORIDA AND KEEPING ISAAC ON A MOSTLY NORTHWESTWARD HEADING
ACROSS THE EASTERN AND NORTH-CENTRAL GULF MEXICO. THE OFFICIAL
FORECAST TRACK IS CLOSE TO THE CONSENSUS MODELS TVCA AND TV15
THROUGH 48 HOURS...AND THEN IS A LITTLE TO THE RIGHT OF THOSE
MODELS AFTER THAT.

http://www.nhc.noaa.gov/text/refresh/MIATCDAT4+shtml/242055.shtml

Given the stronger intensity and the likelihood of less land interaction with Haiti and Cuba (due to Isaac threading the Mona Passage), South FL and the Keys might need to watch out, as the stronger TC might go even farther north before turning back to the NW in about one and a half days.

[Canelaw99]

Talked with my sister down in Ft Lauderdale......not a concern in the world. "Just gonna get a little wind, they say its gonna hit way down in the Keys....." Hope this is not the prevelant attitude in south FLA......MGC

Sadly, this seems to be the attitude of those I've seen in stores, and friends I've talked too. No one down here seems the least bit concerned.