Hurricane Isaac

[knocker]

Almost certainly in my opinion, pressure has dropped 5mb in the past 6 hours (wind often lags) and the picture shows it is about to pop an eye.

I'm intruiged why your opinion should be relied on more than the NHC?

Edited August 26, 2012 by knocker

[Paranoid]

I know they're very difficult to forecast, but what are the chances of EWRCs affecting how much Isaac strengthens? I think (if i remember correctly) Gustav and Ike in 2008 didn't strengthen much despite a lot of warm water in the GOM partly due to undergoing eyewall replacements.

[SMU]

Last few frames of the IR loop

http://www.ssd.noaa.gov/goes/east/gmex/flash-avn.html

Shows perhaps the CDO developing-

I would go with a visible eye developing before light on in the gulf-

Also something to remember is a CAT 4 Hurricane thats strengthening can be worse than a CAT 5 thats weakening on landfall-

S

[summer blizzard]

I'm intruiged why your opinion should be relied on more than the NHC?

No reason but that does not mean that i cannot air my own thoughts.

[SMU]

http://www.ssd.noaa.gov/goes/east/gmex/flash-avn.html

22:45 update ( last frame) looks very worrying if people still think this will stay sub Cat 3-

A well organised CDO developing - a very symetrical shape & all out flow channels look good-

S

[knocker]

No reason but that does not mean that i cannot air my own thoughts.

Of course it doesn't but you were asked the question.

is the NHC being over cautious with their latest forecast wind intensity?

To which you replied.

Almost certainly in my opinion,

Therefore by definition your opinion is better than the NHS. I just find that a tad arrogant.

[summer blizzard]

http://www.ssd.noaa..../flash-avn.html

22:45 update ( last frame) looks very worrying if people still think this will stay sub Cat 3-

A well organised CDO developing - a very symetrical shape & all out flow channels look good-

S

Aye, can see the pin developing now..

[SMU]

yep possibly & that Visible is 30 mins behind my IR-

S

[summer blizzard]

Of course it doesn't but you were asked the question.

To which you replied.

Therefore by definition your opinion is better than the NHS. I just find that a tad arrogant.

Perhaps it sounds like arrogance however it is not.

It is simply the opinion of somebody who has watched the seasons avidly since 04.

[knocker]

BULLETIN

TROPICAL STORM ISAAC ADVISORY NUMBER 23...CORRECTED

NWS NATIONAL HURRICANE CENTER MIAMI FL AL092012

500 PM EDT SUN AUG 26 2012

CORRECTED TROPICAL STORM WARNING AREA FOR FLORIDA PANHANDLE

...CENTER OF ISAAC PASSING JUST SOUTH OF KEY WEST...

SUMMARY OF 500 PM EDT...2100 UTC...INFORMATION

----------------------------------------------

LOCATION...24.2N 82.3W

ABOUT 40 MI...65 KM SW OF KEY WEST FLORIDA

MAXIMUM SUSTAINED WINDS...60 MPH...95 KM/H

PRESENT MOVEMENT...WNW OR 295 DEGREES AT 16 MPH...26 KM/H

MINIMUM CENTRAL PRESSURE...992 MB...29.29 INCHES

WATCHES AND WARNINGS

--------------------

CHANGES WITH THIS ADVISORY...

THE GOVERNMENT OF THE BAHAMAS HAS DISCONTINUED THE TROPICAL STORM

WARNING FOR THE NORTHWESTERN BAHAMAS.

THE GOVERNMENT OF CUBA HAS DISCONTINUED ALL WATCHES AND WARNINGS.

THE TROPICAL STORM WATCH FROM NORTH OF SEBASTIAN INLET TO FLAGLER

BEACH IS DISCONTINUED.

THE HURRICANE WARNING IS CHANGED TO A TROPICAL STORM WARNING FOR THE

FLORIDA KEYS INCLUDING THE DRY TORTUGAS AND FLORIDA BAY.

THE HURRICANE WARNING FOR THE WEST COAST OF FLORIDA FROM BONITA

BEACH SOUTHWARD TO OCEAN REEF IS CHANGED TO A TROPICAL STORM

WARNING.

THE TROPICAL STROM WARNING ALONG THE FLORIDA PANHANDLE HAS BEEN

EXTENDED WESTWARD TO EAST OF DESTIN.

THE HURRICANE WATCH IS CHANGED TO A HURRICANE WARNING FOR THE

NORTHERN GULF OF MEXICO COAST FROM EAST OF MORGAN CITY LOUSIANA TO

DESTIN FLORIDA...INCLUDING METROPOLITAN NEW ORLEANS...LAKE

PONTCHARTRAIN...AND LAKE MAUREPAS.

THE TROPICAL STORM WARNING FROM SUWANNEE RIVER TO TARPON SPRINGS IS

DISCONTINUED.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT...

A HURRICANE WARNING IS IN EFFECT FOR...

* EAST OF MORGAN CITY LOUISIANA TO DESTIN FLORIDA...INCLUDING

METROPOLITAN NEW ORLEANS...LAKE PONTCHARTRAIN...AND LAKE MAUREPAS

A HURRICANE WATCH IS IN EFFECT FOR...

* EAST OF DESTIN TO INDIAN PASS FLORIDA

A TROPICAL STORM WARNING IS IN EFFECT FOR...

* THE FLORIDA PENINSULA FROM SEBASTIAN INLET SOUTHWARD ON THE EAST

COAST AND FROM TARPON SPRINGS SOUTHWARD ON THE WEST COAST.

* FLORIDA KEYS...INCLUDING THE DRY TORTUGAS AND FLORIDA BAY

* LAKE OKEECHOBEE

* EAST OF DESTIN FLORIDA TO THE SUWANNEE RIVER

A HURRICANE WARNING MEANS THAT HURRICANE CONDITIONS ARE EXPECTED

SOMEWHERE WITHIN THE WARNING AREA...IN THIS CASE WITHIN THE NEXT 24

HOURS. PREPARATIONS TO PROTECT LIFE AND PROPERTY SHOULD BE RUSHED

TO COMPLETION.

A HURRICANE WATCH MEANS THAT HURRICANE CONDITIONS ARE POSSIBLE

WITHIN THE WATCH AREA. A WATCH IS TYPICALLY ISSUED 48 HOURS

BEFORE THE ANTICIPATED FIRST OCCURRENCE OF TROPICAL-STORM-FORCE

WINDS...CONDITIONS THAT MAKE OUTSIDE PREPARATIONS DIFFICULT OR

DANGEROUS.

A TROPICAL STORM WARNING MEANS THAT TROPICAL STORM CONDITIONS ARE

EXPECTED SOMEWHERE WITHIN THE WARNING AREA WITHIN 36 HOURS.

FOR STORM INFORMATION SPECIFIC TO YOUR AREA...INCLUDING POSSIBLE

INLAND WATCHES AND WARNINGS...PLEASE MONITOR PRODUCTS ISSUED BY

YOUR LOCAL NATIONAL WEATHER SERVICE FORECAST OFFICE.

DISCUSSION AND 48-HOUR OUTLOOK

------------------------------

AT 500 PM EDT...2100 UTC...THE CENTER OF TROPICAL STORM ISAAC WAS

LOCATED NEAR LATITUDE 24.2 NORTH...LONGITUDE 82.3 WEST. ISAAC IS

MOVING TOWARD THE WEST-NORTHWEST NEAR 16 MPH...26 KM/H...AND A

GRADUAL TURN TOWARD THE NORTHWEST WITH A DECREASE IN FORWARD SPEED

IS EXPECTED OVER THE NEXT 48 HOURS. ON THE FORECAST TRACK...THE

CENTER IS EXPECTED TO MOVE AWAY FROM THE FLORIDA KEYS TONIGHT...

MOVE OVER THE EASTERN GULF OF MEXICO ON MONDAY...AND APPROACH THE

NORTHERN GULF COAST ON TUESDAY.

MAXIMUM SUSTAINED WINDS ARE NEAR 60 MPH...95 KM/H...WITH HIGHER

GUSTS. SOME STRENGTHENING IS FORECAST DURING THE NEXT 48

HOURS...AND ISAAC IS EXPECTED TO BECOME A HURRICANE IN A DAY OR

TWO.

TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 205 MILES...335 KM

FROM THE CENTER. SMITH SHOAL LIGHT...NEAR KEY WEST...REPORTED A

WIND GUST TO 70 MPH...113 KM/H...AND VIRGINIA KEY REPORTED A WIND

GUST TO 66 MPH...106 KM/H.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 992 MB...29.29 INCHES.

HAZARDS AFFECTING LAND

----------------------

RAINFALL...TOTAL RAINFALL ACCUMULATIONS OF 4 TO 7 INCHES...WITH

MAXIMUM AMOUNTS OF 10 INCHES...ARE POSSIBLE ACROSS THE FLORIDA

KEYS AND THE SOUTHERN HALF OF THE FLORIDA PENINSULA. TOTAL

RAINFALL AMOUNTS OF 5 TO 10 INCHES...WITH MAXIMUM AMOUNTS OF 15

INCHES...ARE POSSIBLE ALONG THE EASTERN AND CENTRAL GULF COAST.

WIND...TROPICAL STORM CONDITIONS ARE OCCURRING OVER PORTIONS OF

SOUTHERN FLORIDA AND THE FLORIDA KEYS...AND SHOULD SPREAD NORTHWARD

ALONG THE FLORIDA WEST COAST IN THE TROPICAL STORM WARNING AREA.

TROPICAL STORM CONDITIONS ARE EXPECTED TO REACH THE NORTHERN GULF

COAST IN THE WARNING AREA BY LATE MONDAY...WITH HURRICANE

CONDITIONS EXPECTED ON TUESDAY.

STORM SURGE...THE COMBINATION OF A STORM SURGE AND THE TIDE WILL

CAUSE NORMALLY DRY AREAS NEAR THE COAST TO BE FLOODED BY RISING

WATERS. THE WATER COULD REACH THE FOLLOWING DEPTHS ABOVE GROUND IF

THE PEAK SURGE OCCURS AT THE TIME OF HIGH TIDE...

* NORTHERN GULF COAST WITHIN THE HURRICANE WARNING AREA...6 TO 12 FT

* REMAINDER OF THE FLORIDA PANHANDLE AND APALACHEE BAY...4 TO 7 FT

* FLORIDA WEST COAST SOUTH OF APALACHEE BAY...2 TO 4 FT

* SOUTHEAST FLORIDA COAST AND THE FLORIDA KEYS...1 TO 3 FT

* CENTRAL AND WESTERN CUBA...1 TO 3 FT

* NORTHWESTERN BAHAMAS...1 TO 3 FT

THE DEEPEST WATER WILL OCCUR ALONG THE IMMEDIATE COAST IN AREAS OF

ONSHORE FLOW. SURGE-RELATED FLOODING DEPENDS ON THE RELATIVE TIMING

OF THE SURGE AND THE TIDAL CYCLE...AND CAN VARY GREATLY OVER SHORT

DISTANCES. FOR INFORMATION SPECIFIC TO YOUR AREA...PLEASE SEE

PRODUCTS ISSUED BY YOUR LOCAL WEATHER SERVICE OFFICE. NEAR THE

COAST...THE SURGE WILL BE ACCOMPANIED BY LARGE AND DANGEROUS WAVES.

TORNADOES...ISOLATED TORNADOES ARE POSSIBLE OVER CENTRAL AND

SOUTHERN FLORIDA THOUGH TONIGHT.

SURF...DANGEROUS SURF AND RIP CURRENT CONDITIONS WILL CONTINUE TO

AFFECT THE CENTRAL AND NORTHWESTERN BAHAMAS...CENTRAL CUBA...THE

FLORIDA PENINSULA AND THE FLORIDA KEYS DURING THE NEXT COUPLE OF

DAYS. PLEASE CONSULT PRODUCTS FROM YOUR LOCAL WEATHER OFFICE FOR

MORE INFORMATION.

NEXT ADVISORY

-------------

NEXT INTERMEDIATE ADVISORY...800 PM EDT.

NEXT COMPLETE ADVISORY...1100 PM EDT.

$$

FORECASTER PASCH/ROBERTS

[Thunder Snow]

What cat was katrian when se made landfall

[knocker]

Well it made a couple of landfalls but I think it was a cat 3 by then. But no doubt I'll be corrected on that.

Edited August 26, 2012 by knocker

[Kain]

What cat was katrian when se made landfall

3 if I remember right.

I see Isaac's convection is exploding on the latest loops.

[Chris D]

OK, looking alright on satellite, but yet to develop an eye. Expecting one soon. Anticipating 0000z update.

Worrying this one, have to say.

00z update: only 5mph increase and slighty lower pressure. Bit odd.

Edited August 27, 2012 by Chris D

[AderynCoch]

Would I be right in thinking that Issac could now interact with the Gulf Loop Current?

It's definitely possible now that the forecast track has shifted westwards over the past 24 hours, but a lot depends on how potent the current actually is. Right now it's not as potent as it was when Katrina and Rita went beserk in 2005, according to the following article.:

http://www.wwltv.com...-167382495.html

Meteorologists watch loop current as Isaac moves through Gulf

Ashley Rodrigue / Eyewitness News

All eyes have not been on Tropical Storm Isaac at the National Weather Service in Slidell.

Some are on the atmosphere around the storm, including the water, which meteorologists say is just as important as the storm itself.

NWS Meteorologist Mike Koziara said, "The oceanic heat content is sort of like an ignition source, a fuel source."

And that can be found in the loop current. The loop current is a ribbon of warm water that wraps from the Caribbean Sea, around Cuba, through the Florida Straights and up the East Coast. The loop's high temperature can boost a storm's strength and Isaac is headed right for it.

"It could be a player, it could be a big player," said Koziara, "The problem with nature is, the deck constantly gets shuffled for us."

Even though Isaac's path is predicted to go across the loop current, meteorologists here say the stars sort of have to align in order for Isaac to do what Hurricane Katrina did in 2005.

Koziara said, "You had a very large area of warm oceanic heat content in the southeastern Gulf in 2005 and Katrina was a hurricane in intensifying mode and it moved over this area of high oceanic heat content and it was able to ingest all this heat energy."

That boosted the storm to a Category 5. But today, the water isn't that warm, the loop isn't that wide and Isaac isn't that organized. So for now, at the National Weather Service in Slidell, "The jury's still out on Isaac," said Koziara.

Forecasters want to remind people that just like the path of a storm can change, so can the warmth of the loop and its size.

Certainly not much of a Loop Current anomaly apparent on the latest SST charts. If I recall correctly it was at 32C+ when Katrina passed over it.

Edited August 27, 2012 by AderynCoch

[Chris D]

Looking at this realistically, I think weak Cat 4 is the absolute max it will be.

Saying that, if it occurs, it will cause incredible damage. Gut feeling is Cat 3.

Edited August 27, 2012 by Chris D

[AderynCoch]

Another thing to bear in mind is that although Katrina was Cat. 3 at landfall (sustained Cat. 4 winds were experienced just prior to the eye touching the coast), it was a very large storm which had just come down from Cat. 5 and so the storm surge was still Category 5-equivalent - hence the unbelievable amount of destruction caused in comparison to other Category 3 landfalls. Camille made landfall as a Cat. 5 storm in 1969 (sustained winds estimated at 190mph!) and yet Katrina matched it with regards to storm surge and the scenes of devastation along the Gulf Coast. Storm surge is usually the main cause of destruction when it comes to hurricanes in this area

A storm strengthening to Cat. 3 is still very dangerous of course, but Katrina was no ordinary Cat. 3 hurricane when it hit the Gulf Coast.

Edited August 27, 2012 by AderynCoch

[Iceberg]

Morning All.

Firstly the model forecasts quickly: All models now take isaac to the swamps of new orleans in approx 48 hrs even the ecm now. Once there is also general agreement that Isaac will stall for 24 hrs moving only steadily(there is no agreement on which way he moves once stalling though, ecm ne, gfs nw)

Intensity is generally as a CAT 3, however gfdl is a cat 1 and hwrf a cat 4.

Isaac only has 48 hrs to intensify though, winds take 6 hrs to respond to pressure falls so that only allow a small window of development and for anything above a cat 2 rapid intensification needs to happen and this cannot be predicted accurately by models. RI might or might not happen, he has good ssts but lacks the upper high to give the outflow and strong inflow channels, gfdl also predicts shear to effect the system and the centre of isaac is not in the centre of the CDO.

Given all this i would only put the chances of RI at 25%.

Current Radar loops shows a partial eye wall but no concrete eye yet. 36 hrs for the eye wall to develop, clear out, inflow, outflow etc all to establish is pushing it imho hence the NHC official forecast of 85kts at landfall.

Recon are going into the storm again take off approx 45 mins ago with first reading in 1 hr or so.

Given the above the biggest problem with isaac will be flooding with upto 5-10inchs of rain forecast for the NO area and districts. Added to this we have a surge predicted of 10-12ft above normal levels for the bay.

Re size Isaac is nowhere near the size of large hurricane for pressure and predicted hurricane winds which will be quite small in area, rainfall and ts spreads are large though.

[geoffw]

any money my calls for not above cat 2 made days ago will be proved correct

[Iceberg]

not by me geoff, impossible to judge what will happen re intensity but the nhc estimate looks realistic, however it will need watching like a hawk

[Iceberg]

recon are in 998mb so far on the way towards the centre (roughly they have entered the cdo but not yet got to the centre)

[mezzacyclone]

08:46: 25.383N 84.150W 989.4mb,,,

[Iceberg]

centre pass just made. Pressure has fallen a little to a minium of 989.4mb, the eye stiil looks poorly organised to me, but radar does show its steadily getting its act together. No doubt recon will find slighly lower still on the next pass

084400 2522N 08415W 8429 01417 9903 +199 +190 319006 010 023 015 03

084430 2522N 08414W 8431 01412 9900 +200 +191 260005 007 020 016 03

084500 2523N 08412W 8426 01415 9897 +203 +186 210011 014 020 016 03

084530 2524N 08410W 8433 01411 9897 +208 +188 182017 019 010 016 03

084600 2523N 08409W 8427 01419 9894 +220 +171 179022 023 015 019 03

084630 2522N 08408W 8424 01427 9898 +222 +168 168029 032 024 016 00

084700 2521N 08406W 8422 01428 9908 +201 +179 194021 029 026 014 00

084730 2520N 08405W 8433 01418 9911 +198 +185 205024 025 027 015 00

0848

recon got the centre recording pretty much where the centre is on radar which is good news.

[mezzacyclone]

has their been some slight mid-level vert shear Ice? Something`s prevented further strengthening as I figured on a cat1 by this morning?

Definitely in a decreasing shear sector now so today`s the day?

[Iceberg]

Yep I think gfdl has successfully forecasted a but of shear it should let up, but gfdl does continue it so worth thinking about

Also the size of the inner core is very large which is preventing the eye wall from establishing,this is probably due to it being so close to land for so long.

Two aircraft in ATM and the second has found pressure down to 992mb or so

Basically Isaac needs to shape up and tighten up as he's far too flabby.