ATL: ISAAC - Post-Tropical - Discussion

[rtd2]

As the death toll of Isaac is now over 20, will it be a candidate for name retirement? Has a tropical storm, as opposed to a hurricane, ever had its name retired in the past?

Oh yes.

http://en.wikipedia.org/wiki/Tropical_Storm_Allison

Tropical Storms can cause massive amounts of grief.

Oh why'd you have to remind us....

[otowntiger]

Will any of the rain from this system reach the heartland? The farmers need rain so badly....

I am starting to wonder if the rain will even reach as far north as I am (Baton Rouge) with everything on the southern side of the storm and models showing this hugging the coast. We may just have a rather gusty 24 hour period with some spotty showers. Not complaining, but not what I was expecting 2-3 days ago, at all.

Ha! You'll get your share of rain, don't worry.

[rainstorm]

the latest hrrr keeps it south going due west.

http://rapidrefresh.noaa.gov/hrrrconus/ ... =t6&wjet=1

[Wx_Warrior]

Wow. Allison brings back memories. Bad memories, for me and millions of others anyways. Ruined my Astroworld plans than many of belongings.

[Texashawk]

I am not liking these model trends. Problem is, it's too much of a change for the NHC to make that kind of a flip, so I wonder if the new models hold how much trouble that will be down the road for SW LA/E TX?

[HurrMark]

Surprise, surprise...still a TS.

I think post-analysis may consider this a hurricane (like Gaston), but I am starting to doubt if this ever will be a hurricane operationally.

[WeatherGuesser]

10:00 AM CDT Tue Aug 28
Location: 28.1°N 88.5°W
Moving: NW at 10 mph
Min pressure: 976 mb
Max sustained: 70 mph

..ISAAC STILL JUST BELOW HURRICANE STRENGTH

[sponger]

Astroworld is still there? Went in 79!!!

[Wx_Warrior]

10a NHC advisory

000
WTNT34 KNHC 281458
TCPAT4

BULLETIN
TROPICAL STORM ISAAC ADVISORY NUMBER 30
NWS NATIONAL HURRICANE CENTER MIAMI FL AL092012
1000 AM CDT TUE AUG 28 2012

...ISAAC STILL JUST BELOW HURRICANE STRENGTH AS IT CONTINUES
NORTHWESTWARD...


SUMMARY OF 1000 AM CDT...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...28.1N 88.5W
ABOUT 80 MI...125 KM SSE OF THE MOUTH OF THE MISSISSIPPI RIVER
ABOUT 165 MI...260 KM SE OF NEW ORLEANS LOUISIANA
MAXIMUM SUSTAINED WINDS...70 MPH...110 KM/H
PRESENT MOVEMENT...NW OR 310 DEGREES AT 10 MPH...17 KM/H
MINIMUM CENTRAL PRESSURE...976 MB...28.82 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY...

THE HURRICANE WARNING HAS BEEN REPLACED WITH A TROPICAL STORM
WARNING FROM THE MISSISSIPPI-ALABAMA BORDER EASTWARD TO DESTIN
FLORIDA.

THE TROPICAL STORM WARNING HAS BEEN DISCONTINUED EAST OF DESTIN.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT...

A HURRICANE WARNING IS IN EFFECT FOR...
* EAST OF MORGAN CITY LOUISIANA TO THE MISSISSIPPI-ALABAMA BORDER...
INCLUDING METROPOLITAN NEW ORLEANS...LAKE PONTCHARTRAIN...AND LAKE
MAUREPAS

A HURRICANE WATCH IS IN EFFECT FOR...
* INTRACOASTAL CITY TO MORGAN CITY LOUISIANA

A TROPICAL STORM WARNING IS IN EFFECT FOR...
* THE MISSISSIPPI-ALABAMA BORDER TO DESTIN FLORIDA
* MORGAN CITY TO CAMERON LOUISIANA

A TROPICAL STORM WATCH IS IN EFFECT FOR...
* EAST OF HIGH ISLAND TEXAS TO JUST WEST OF CAMERON LOUISIANA

A HURRICANE WARNING MEANS THAT HURRICANE CONDITIONS ARE EXPECTED
SOMEWHERE WITHIN THE WARNING AREA. 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 TROPICAL STORM WARNING MEANS THAT TROPICAL STORM CONDITIONS ARE
EXPECTED SOMEWHERE WITHIN THE WARNING AREA.

A TROPICAL STORM WATCH MEANS THAT TROPICAL STORM CONDITIONS ARE
POSSIBLE WITHIN THE WATCH AREA.

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 1000 AM CDT...1500 UTC...THE CENTER OF TROPICAL STORM ISAAC WAS
LOCATED NEAR LATITUDE 28.1 NORTH...LONGITUDE 88.5 WEST. ISAAC IS
MOVING TOWARD THE NORTHWEST NEAR 10 MPH...17 KM/H. A NORTHWESTWARD
MOTION AT A SLIGHTLY SLOWER SPEED IS EXPECTED OVER THE NEXT DAY OR
TWO. ON THE FORECAST TRACK...THE CENTER OF ISAAC SHOULD REACH THE
COASTLINE OF SOUTHEASTERN LOUISIANA AS EARLY AS THIS EVENING.

MAXIMUM SUSTAINED WINDS ARE NEAR 70 MPH...110 KM/H...WITH HIGHER
GUSTS. ISAAC IS EXPECTED TO BECOME A HURRICANE BEFORE MAKING
LANDFALL...AND BEGIN TO SLOWLY WEAKEN AFTER THAT.

TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 185 MILES...295 KM
FROM THE CENTER.

THE LATEST MINIMUM CENTRAL PRESSURE REPORTED BY HURRICANE HUNTER
AIRCRAFT WAS 976 MB...28.82 INCHES.


HAZARDS AFFECTING LAND
----------------------
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...

* MISSISSIPPI AND SOUTHEASTERN LOUISIANA...6 TO 12 FT
* ALABAMA...4 TO 8 FT
* SOUTH-CENTRAL LOUISIANA...3 TO 6 FT
* FLORIDA PANHANDLE...3 TO 6 FT
* APALACHEE BAY...2 TO 4 FT
* REMAINDER OF FLORIDA WEST COAST...1 TO 3 FT

THE DEEPEST WATER WILL OCCUR ALONG THE IMMEDIATE COAST IN AREAS OF
ONSHORE WINDS. 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.

WIND...TROPICAL STORM CONDITIONS ARE BEGINNING TO OCCUR NEAR THE
MOUTH OF THE MISSISSIPPI RIVER...AND WILL REACH OTHER PORTIONS OF
THE COASTLINE WITHIN THE TROPICAL STORM AND HURRICANE WARNING AREAS
BY LATE THIS AFTERNOON. HURRICANE CONDITIONS ARE EXPECTED TO REACH
THE COAST BY LATE AFTERNOON.

RAINFALL...ISAAC IS EXPECTED TO PRODUCE TOTAL RAINFALL AMOUNTS OF
7 TO 14 INCHES...WITH POSSIBLE ISOLATED MAXIMUM AMOUNTS OF 20
INCHES...IN SOUTHEASTERN LOUISIANA...SOUTHERN MISSISSIPPI...
SOUTHERN ALABAMA...AND THE EXTREME WESTERN FLORIDA PANHANDLE.
THESE RAINS COULD RESULT IN SIGNIFICANT LOWLAND FLOODING.

TORNADOES...TORNADOES MAY OCCUR ALONG THE NORTHERN GULF COAST TODAY.

SURF...DANGEROUS SURF AND RIP CURRENT CONDITIONS WILL CONTINUE TO
AFFECT THE FLORIDA COASTLINE AND PORTIONS OF THE NORTHERN GULF COAST
FOR THE NEXT DAY OR SO.


NEXT ADVISORY
-------------
NEXT INTERMEDIATE ADVISORY...100 PM CDT.
NEXT COMPLETE ADVISORY...400 PM CDT.

$$
FORECASTER STEWART

[cycloneye]

Excerpt from 10 AM CDT discussion.

REPORTS FROM AIR FORCE AND NOAA HURRICANE HUNTER AIRCRAFT INDICATE
THE CENTRAL PRESSURE HAS DECREASED TO ABOUT 976 MB SINCE THE
PREVIOUS ADVISORY...BUT IT HAS LEVELED OFF OVER THE PAST FEW HOURS.
THE MAXIMUM 850 MB FLIGHT-LEVEL WIND OBSERVED HAS BEEN 89 KT...
WHICH EQUATES TO A SURFACE WIND OF ABOUT 71 KT. HOWEVER...
BIAS-ADJUSTED SFMR SURFACE WINDS HAVE ONLY BEEN AROUND 60-62 KT...
WHICH CORRELATES WELL WITH DROPSONDE BOUNDARY LAYER-DERIVED SURFACE
WINDS. AS SUCH...THE INTENSITY OF ISAAC IS BEING MAINTAINED AT 60
KT...WHICH IS JUST BELOW HURRICANE STATUS.

[sponger]

Best looking tropical storm on vis ever. IMHO. Not a suprise with what recon has been finding. I still say this makes 80 by landfall! Just my amateur opinion.

[tolakram]

Center Visible: http://www.ssec.wisc.edu/~rabin/goes14/loop_srso.html

[GCANE]

Anti-cyclone has shifted to the NW of the LLC.

Shear now at 2.5 m/s

Rain rate increasing

http://www.nrlmry.navy.mil/htdocs_dyn_p ... atest.html

CAPE at 2500 in the core

http://www.spc.noaa.gov/exper/mesoanaly ... sector=18#

[Texashawk]

Still no significant track change. Guess the pros are seeing something we don't, which is usually the case.

[otowntiger]

Surprise, surprise...still a TS.

I think post-analysis may consider this a hurricane (like Gaston), but I am starting to doubt if this ever will be a hurricane operationally.

Wow. I'm not surprised but yet I am. Isaac is indeed a unique storm. Just like Louisiana! And I know, I'm a native.

[WilmingtonSandbar]

Center Visible: http://www.ssec.wisc.edu/~rabin/goes14/loop_srso.html

[ img]http://img717.imageshack.us/img717/784/zztemp.jpg[/img]

I don't think that is an eye in the center, I think it is dry air. If that's the case, I expect a little weakening while Isaac chokes some.

[nautical wheeler]

Do you think all of the dry air is a result from the epic drought in the midwest? Usually it is wetter up that way? I believe we combine that with, and I know people argue this, but all of the rain we have had over the last 4 weeks (huge amounts around 40 inches) cooling the gulf, as well as a lot more cloud cover keeping the water cooler. I know for a fact the water is a lot cooler this year than when we have had big hurricanes.

I noticed when the issue of dry air came up as it was approaching the SE Gulf, there was some unusually dry air over the Yucatan peninsula which that ULL was kicking up into the S side of the storm and being engulfed. That ULL also was pulling air all the way from northern Texas/Oklahoma in what appeared on the water vapor imagery as a "stream." I wish I knew how to go back in time on the WV to post that image but I don't know how to do that. It was very interesting. There was a stream of red color on WV. So you may be on to something with that.

I thought as that ULL relaxed it would eventually cycle that dry air out, but there is also plenty of dry air to the north under the ridge in the SEUS which I'm sure is being engulfed as well. So it was getting hit from both sides.

Not a pro met obviously but those were my observations as it crossed the Gulf.

[Chris_in_Tampa]

High Values NOAA HDOB 44
Flight (30s): 90 knots
Flight (10s): 90 knots
SFMR Surface (10s): 63 knots

An important 1 knot off I guess.

[Dave]

Heartland rainfall amounts for those who were wondering. Valid from 8 am today to 8 am Sep 2nd. (NOAA/NWS/NCEP/HPC)

http://www.fallsky.com/isaac/isaacrainfall.gif

[windnrain]

In the past, it seems to me like 87 KT flight winds being detected ALWAYS led to a hurricane being declared. Is it just that our technology is better now and so we adjust it further down? I always seem to remember like a 15% reduction for FL winds...