Hurricane Idalia

[WxWatcher007]

Welp  

5:00 PM EDT Tue Aug 29
Location: 26.1°N 84.8°W
Moving: N at 16 mph
Min pressure: 972 mb
Max sustained: 100 mph

CHANGES WITH THIS ADVISORY:

A Hurricane Watch has been issued from the mouth of the St. Mary's
River northward to Edisto Beach.

A Storm Surge Watch has been issued from Beaufort Inlet to Drum
Inlet, North Carolina, as well as the Neuse and Pamlico Rivers.

A Tropical Storm Warning has been issued from South Santee River
northward to Surf City, North Carolina.  A Tropical Storm Watch has
been issued north of Surf City to the North Carolina/Virginia
border, including Pamlico and Albemarle Sounds.

The Hurricane Watch from Englewood to the Middle of Longboat Key
has been discontinued.

The Storm Surge Watch has been discontinued south of Bonita Beach,
Florida.

[StantonParkHoya]

They just said 100, but that’s not based on findings

[Rtd208]

Idalia is a CAT 2 now 100 mph winds

[CoastalWx]

100? Could have fooled me.

[Normandy]

The first pass is interesting because it’s suggestive of a storm that is extremely imbalanced but not necessarily weak.  Large swatch of strong flight level winds and the wind gradient was steep exiting into the SE eyewall.  As this burst continues will be interesting to see winds in the other quads.  

[the_other_guy]

Wasn’t this always supposed to be a weaker hurricane that had sheer issues holding back intensification? I remember saying this like four days ago. I know it got hyped up in the last 48 hours but this is playing out exactly as planned.

[Rtd208]

Just now, CoastalWx said:

100? Could have fooled me.

I am a bit suprised based on recon findings. 

[cptcatz]

There's a nasty feeder band about to come through my house in Boca Raton.  Should get interesting.

[GaWx]

1 minute ago, WxWatcher007 said:

Welp  

5:00 PM EDT Tue Aug 29
Location: 26.1°N 84.8°W
Moving: N at 16 mph
Min pressure: 972 mb
Max sustained: 100 mph

CHANGES WITH THIS ADVISORY:

A Hurricane Watch has been issued from the mouth of the St. Mary's
River northward to Edisto Beach.

A Storm Surge Watch has been issued from Beaufort Inlet to Drum
Inlet, North Carolina, as well as the Neuse and Pamlico Rivers.

A Tropical Storm Warning has been issued from South Santee River
northward to Surf City, North Carolina.  A Tropical Storm Watch has
been issued north of Surf City to the North Carolina/Virginia
border, including Pamlico and Albemarle Sounds.

The Hurricane Watch from Englewood to the Middle of Longboat Key
has been discontinued.

The Storm Surge Watch has been discontinued south of Bonita Beach,
Florida.

Ouch! Hurricane watch GA and lower SC coast. Hope this is overdone but it has been a worry. Hopefully the struggles of the storm that have been mentioned here are actually going to keep it from reaching major status. But it isn't looking good right now.

[WxSynopsisDavid]

I been told they are using drones to also recon Idalia. That data set is not available to the public. It’s possible they got the 100mph reading using other methods instead of Recon Hunters.

[hlcater]

91kts FL is what they based it on, along with the pretense that the NE quad has not been sampled yet. Decent strengthening from the last pass, but perhaps not as rapid as models had indicated. However, the storm is in good shape for more robust strengthening tonight. Still think an intensity of 110-115kts is a pretty reasonable guess for landfall.

[WxWatcher007]

Hurricane Idalia Discussion Number  13
NWS National Hurricane Center Miami FL       AL102023
500 PM EDT Tue Aug 29 2023

The first stages of an eye have been taking shape in visible
satellite imagery.  The hurricane has a relatively small Central
Dense Overcast and a prominent band of deep convection extending
over the eastern semicircle, reaching across the Florida peninsula
southward across western Cuba.  An Air Force Reserve Hurricane 
Hunter aircraft just measured a peak 700-mb flight-level wind of 91 
kt with the pressure falling to 972 mb.  The initial intensity is 
therefore set at 85 kt.

Idalia is moving faster toward the north, or 360/14 kt, between a
mid-level trough over the northwestern Gulf of Mexico and a
subtropical ridge over the Greater Antilles.  Idalia is expected to
continue moving northward and turn north-northeastward as it
approaches the Big Bend region of Florida during the next 12-24
hours.  There is very little spread among the track guidance, and
the NHC official forecast has been placed very close to the HCCA
and TVCX consensus aids during the first 24 hours.  This has
resulted in a westward shift of about 20-25 n mi compared to the
previous forecast, although it should be stressed that additional
shifts to the track will be possible until the center reaches land.

After landfall, Idalia is expected to turn toward the northeast and
then east, moving near or along the coast of Georgia and the
Carolinas in 36-48 hours.  Uncertainty in the track forecast is
still quite large after 48 hours, with many of the global models
turning Idalia southward, while some of the regional hurricane
models still show the storm moving out to sea.  As a result, the
official track forecast continues to show slow motion on days 4 and
5.

The 12-hour intensity forecast shows a 100-kt major hurricane.  It
is imperative to realize that Idalia is expected to continue
strengthening beyond that time, possibly close to the 110 kt shown
in the previous forecast, before the center reaches land.
Weakening is expected after landfall, but due to the system's
expected fast motion, it is possible that Idalia could maintain
hurricane intensity as it moves across southern Georgia and 
approaches the coasts of Georgia and South Carolina.  After 
Idalia's center moves offshore over the western Atlantic, strong 
shear is likely to limit re-intensification, and the official 
forecast essentially flatlines the intensity on days 2-5.


KEY MESSAGES:

1. Catastrophic impacts from storm surge inundation of 10 to 15 feet 
above ground level and destructive waves are expected somewhere 
between Aucilla River and Yankeetown, Florida. Life-threatening 
storm surge inundation is likely elsewhere along portions of the 
Florida Gulf Coast where a Storm Surge Warning is in effect.  
Residents in these areas should follow any advice given by local 
officials.

2. There is the potential for destructive life-threatening winds 
where the core of Idalia moves onshore in the Big Bend region of 
Florida, with hurricane conditions expected elsewhere in portions of 
the Hurricane Warning area along the Florida Gulf Coast. Strong 
winds will also spread inland across portions of northern Florida 
and southern Georgia near the track of the center of Idalia where 
Hurricane Warnings are in effect. Residents in these areas should be 
prepared for long-duration power outages. Damaging hurricane-force 
winds are possible in portions of eastern Georgia and southeastern 
South Carolina where Hurricane Watches are in effect. 

3. Areas of flash, urban, and moderate river flooding, with locally 
considerable impacts, are expected across the Florida Big Bend, 
central Georgia and South Carolina, through eastern North Carolina 
later tonight into Thursday.



FORECAST POSITIONS AND MAX WINDS

INIT  29/2100Z 26.1N  84.8W   85 KT 100 MPH
 12H  30/0600Z 28.3N  84.5W  100 KT 115 MPH
 24H  30/1800Z 31.0N  82.9W   75 KT  85 MPH...INLAND
 36H  31/0600Z 32.9N  80.2W   50 KT  60 MPH...INLAND
 48H  31/1800Z 33.9N  77.1W   45 KT  50 MPH...OVER WATER
 60H  01/0600Z 33.8N  74.2W   45 KT  50 MPH
 72H  01/1800Z 33.3N  71.8W   45 KT  50 MPH
 96H  02/1800Z 32.3N  69.6W   45 KT  50 MPH
120H  03/1800Z 31.7N  69.0W   45 KT  50 MPH

$$
Forecaster Berg

[CoastalWx]

So a random 91kt FL wind at 700mb translates to 100mph at the surface? Not sure how I feel about that. 

[GaWx]

From 5PM NHC discussion: "This has
resulted in a westward shift of about 20-25 n mi compared to the
previous forecast"

 This makes sense based on 12Z model consensus.

[friedmators]

VHTs going up everywhere.

[CoastalWx]

Finally see some signs of deeper convection wrapping around the center. Should this continue, you'll eventually see the center warm on IR imagery and clear out.

[CCHurricane]

26 minutes ago, GaWx said:

Maybe this won't end up as a major H landfall. Fingers crossed! Perhaps their climo says that there are geographic factors that make it extremely difficult and that that will come into play for Idalia. Thoughts?

Alma (1966) and the Unnamed Hurricane in 1886 are really the only two storms with a similar origin / track. Obvious not statistically significant, yet both storms only maintained or weakened upon their approach to the area, neither strengthened. 

The current climo is of course different than the past, particularly the extremely water temps, so we'll wait and see what happens with Idalia.

[Amped]

The eyewall has improved quite a bit. There will probably be a decent wind increase in the next pass through the eastern portion of the eye.

[Prospero]

I keep waiting for some serious Idalia winds on SailFlow and right now south east Florida appears to have stronger winds than the Gulf Coast. Are those wind speeds due to Franklin?

[NJwx85]

Just got hit with an outer band here. Poured for 5 miniutes and gusted to about 30mph. Location : Disney 

[Rmine1]

Satellite representation showing Idalia starting to take off.

[WxWatcher007]

Second recon plane moving into the NE quadrant. Not sure what's up with the first plane as it hasn't transmitted data in a while. 

Folks near Tallahassee need to take this seriously. The 18z spaghetti models shifted west again and the 18z GFS holds compared to 12z. Looking at the ensemble consensus, more changes are definitely possible and it's unusual for the NHC to note it in a discussion approximately 12-18 hours before a landfall.  

 

[Hotair]

Eye wall is clearing on sat.  First time I see a respectable eye wall on Idalia. 

[Wannabehippie]

On the last couple of visible satellite photos, it looks like Idalia is trying to clear out the eye.

[BYG Jacob]

Looks like a trio of rotating VHT. Should see some significant pressure falls and wind increases.

[Windspeed]

The next 12 hours are going to be intense. We're getting into a more favorable upper environment from this point until landfall that should continue to improve. I do expect the eyewall to take off tonight. It may not have time to enter into an ERC before landfall now, either. So it may very well still be deepening at landfall. I do think this will reach lower end Cat 4 as it is coming ashore. I'd like to imagine there's just not enough time for it to reach any maximum potential given the environment.

[MANDA]

Said this morning I was expecting to see an eye by sunset....Idalia is trying very hard to get there!  Overshooting clouds tops pretty much wrapping around the center for the first time.  CDO is rather small and compact though.

[WxWatcher007]

Note how the NHC track is still east of the model consensus...that is still ticking west. I think there's lower than normal confidence in where the center makes landfall. 

 

 

[WxWatcher007]

2 minutes ago, Windspeed said:

The next 12 hours are going to be intense. We're getting into a more favorable upper environment from this point until landfall that should continue to improve. I do expect the eyewall to take off tonight. It may not have time to enter into an ERC before landfall now, either. So it may very well still be deepening at landfall. I do think this will reach lower end Cat 4 as it is coming ashore. I'd like to imagine there's just not enough time for it to reach any maximum potential given the environment.

Look at the distribution of RI odds, particularly relative to climo. 

[wkd]

36 minutes ago, GaWx said:

Maybe this won't end up as a major H landfall. Fingers crossed! Perhaps their climo says that there are geographic factors that make it extremely difficult and that that will come into play for Idalia. Thoughts?

I'm not a big believer in the idea that 'climo' plays any role in the outcome of any particular event, since it doesn't have any bearing on current synoptic setups.  I would love to see a statistical analysis of U.S landfalls using origin of a depression, SST, winds aloft, position of troughs and ridges and many other parameters. I will admit though that any tropical cyclone entering the Gulf will hit land somewhere unless it dissapates.