Major Hurricane Isaias

[PhiEaglesfan712]

Imelda getting retired, but not Idalia, doesn't make sense though:

Imelda: Cat 1 (90 mph), 3 fatalities, 2 injuries, $10 million damage

Idalia: Cat 4 (145 mph), 12 fatalites (8 direct/4 indirect), $3.5 billion damage

Idalia was the stronger hurricane, caused more damage, and had more casulties. If Imelda was retired, Idalia should have been as well.

[Interstate]

Latest satellite images shows the shear starting to affect the storm.  Also the thunderstorms around the eyewall has collapsed.

[NavarreDon]

I’m going to be providing OBS from Wright FL for the storm. I will provide them periodically as long as conditions/infrastructure allow me too. I saw this highlighted on X a bit ago and it gave me some pause….




.

[vortex95]

1 hour ago, GaWx said:

 
 The point some of us have been making is the double standard being applied regarding the concern for the attendees in Tuscaloosa vs that for those in Atlanta:

 Tuscaloosa: SATURDAY  
TROPICAL STORM CONDITIONS POSSIBLE. SHOWERS, COOLER  
WITH HIGHS IN THE MID 70S. NORTHEAST WINDS 25 TO 30 MPH WITH  
GUSTS UP TO 45 MPH, BECOMING SOUTH 10 TO 15 MPH WITH GUSTS UP TO  
30 MPH IN THE AFTERNOON. CHANCE OF RAIN NEAR 100 PERCENT.

Atlanta: SATURDAY  
SHOWERS. A SLIGHT CHANCE OF THUNDERSTORMS IN THE  
MORNING, THEN A CHANCE OF THUNDERSTORMS IN THE AFTERNOON. BREEZY  
WITH HIGHS IN THE LOWER 70S. EAST WINDS 15 TO 25 MPH WITH GUSTS  
UP TO 50 MPH. CHANCE OF RAIN NEAR 100 PERCENT.

—————

 As one can see, the forecast is actually much worse for the afternoon gametime in ATL for Duke/GT than it is not just for the evening gametime in Tuscaloosa but even during the tailgating time in Tuscaloosa well before the game even starts!

 So, gusts to 50 with possible thunderstorms/heavy rain and even a slight chance for a tornado in ATL for the game itself vs gusts only to 30, much lighter rain, and no thunderstorms in Tuscaloosa during the entire PM tailgating period well before the game even starts!

 @PhiEaglesfan712@vortex95

One thing I do like is stating "tropical storm conditions possible."  Yet the actual forecast is for 15 to 25 mph *sustained* winds.  That is well below the threshold.  Last I checked, tropical conditions are sustained 39 mph or more.  So there is hedging here is excessive IMHO.   Gusts to TS force are not the same as sustained TS force.  They are conflating things.  I see this a lot.

And really, how often does TCL and esp. ATL, get sustained winds of 39 mph or more?  It is practically unheard of.  So climo comes into play here.  It would have to be an exceptional event for such winds, but Isaias as a hurricane and going ET are not by all forecasts.   This is not like Helene from 2 years ago.

Just b/c something has a non-zero chance of occurring does not mean you explicitly mention it in a forecast.  Once again, hedging and inflating reasonable risk.  Wording matters as to how ppl will react, and then you get into the issue of things being cancelled and shutdown *way* too much for a run-of-the-mill event.

Also, Isaias will no longer be a TC by the time ATL gets sig impact, and perhaps even TCL. so their wording is incorrect.  They should be saying "gale force winds", not tropical storm conditions. 

This is a slippery slope.  Almost every winter storm on the E Coast has winds of TS strength, but you do not call them tropical storm winds!

They should be headlining a wind advisory or high wind warning, not mentioning tropical in this case
for TCL and ATL.
 

[Floydbuster]

Radar has degraded so much in just the last hour. Thank goodness.

[vortex95]

1 hour ago, Vicious Fluid said:

This is probably more apparent to those with background in weather/forecasting, but I'm curious: is the outflow from Simon potentially disrupting some of the effect of the sheer on the western side? I know the outflow affects Isaias' ventilation, but does it also have an independent effect on the actual environment of sheer?

That's a good question.  Sometimes the outflow from an EPAC TC does impact a TC in the Gulf.  In this case, Simon's outflow is well-removed and discrete.  The strong upper level trough is dominating the local synoptic environment around Isaias.

[olafminesaw]

4 minutes ago, Floydbuster said:

Radar has degraded so much in just the last hour. Thank goodness.

Kinda looks like a double eyewall has appeared?

[vortex95]

1 hour ago, Interstate said:

Question... when the give the position of a storm... if the position the exact middle of the eye?

Typically yes, but the eye itself can be mess w/ multiple mesovorts rotating around in it!  So finding a true wind center is not always easy.

[vortex95]

41 minutes ago, jm1220 said:

GOM hasn't had any significant tropical activity this year so the waters are quite warm. That helps.

Yes the lack of TC activity has allows the waters to warm more.  That is largely a function of El NIno.  So suppression overall can lead to enhancements for individual TCs that do manage to develop.

[GaWx]

8 minutes ago, vortex95 said:

One thing I do like is stating "tropical storm conditions possible."  Yet the actual forecast is for 15 to 25 mph *sustained* winds.  That is well below the threshold.  Last I checked, tropical conditions are sustained 39 mph or more.  So there is hedging here is excessive IMHO.   Gusts to TS force are not the same as sustained TS force.  They are conflating things.  I see this a lot.

And really, how often does TCL and esp. ATL, get sustained winds of 39 mph or more?  It is practically unheard of.  So climo comes into play here.  It would have to be an exceptional event for such winds, but Isaias as a hurricane and going ET are not by all forecasts.   This is not like Helene from 2 years ago.

Just b/c something has a non-zero chance of occurring does not mean you explicitly mention it in a forecast.  Once again, hedging and inflating reasonable risk.  Wording matters as to how ppl will react, and then you get into the issue of things being cancelled and shutdown *way* too much for a run-of-the-mill event.

Also, Isaias will no longer be a TC by the time ATL gets sig impact, and perhaps even TCL. so their wording is incorrect.  They should be saying "gale force winds", not tropical storm conditions. 

This is a slippery slope.  Almost every winter storm on the E Coast has winds of TS strength, but you do not call them tropical storm winds!

They should be headlining a wind advisory or high wind warning, not mentioning tropical in this case
for TCL and ATL.
 

Thanks.
Whereas for TCL they’ve got a TS warning, they didn’t ever predict TS conditions for ATL. Instead they have a high wind warning:

 

[jbenedet]

Looks like it’s made a turn north

[vortex95]

25 minutes ago, PhiEaglesfan712 said:

Imelda getting retired, but not Idalia, doesn't make sense though:

Imelda: Cat 1 (90 mph), 3 fatalities, 2 injuries, $10 million damage

Idalia: Cat 4 (145 mph), 12 fatalites (8 direct/4 indirect), $3.5 billion damage

Idalia was the stronger hurricane, caused more damage, and had more casulties. If Imelda was retired, Idalia should have been as well.

I meant Imelda from 2019.  You don't see 43" of rain from a TC in the CONUS every day, and Imelda is the second costliest TS on record ($5B), so impact was very high.  Net societal impact matters-more for retirement overall.

[olafminesaw]

Seemingly no pressure rose yet. First pass 957 extrap

[Floydbuster]

9 minutes ago, olafminesaw said:

Kinda looks like a double eyewall has appeared?

Damn just noticed that in the radar frames as you said it. Yeah, that will expand the wind field for sure.

[HKY_WX]

29 minutes ago, NavarreDon said:

I’m going to be providing OBS from Wright FL for the storm. I will provide them periodically as long as conditions/infrastructure allow me too. I saw this highlighted on X a bit ago and it gave me some pause….




.

I agree with the portion that points out the forward motion direction (NNE) aligning with the shear vector reducing its impact on the system. Sure, it may eliminate any chance of strengthening, but a massive drop in strength prior to landfall looks pretty unlikely at this point. 

[HKY_WX]

Destin over towards Miramar Beach are going to take the brunt of this one. The location of the landfall along with the direction of the coastline will funnel a lot of water into those areas.

 

[mob1]

Based on radar it could be a bit more of an eyewall meld than a true EWRC (which is sometimes common as it approaches land and the friction causes it to tighten up a bit) but it's definitely degrading which is welcome timing. 

[olafminesaw]

5 minutes ago, HKY_WX said:

Destin over towards Miramar Beach are going to take the brunt of this one. The location of the landfall along with the direction of the coastline will funnel a lot of water into those areas.

 

 

Destin has a bunch of dense housing and touristy buildings/hotels right on/near the beach too, one of the more vulnerable areas that's more urban

[SnoSki14]

3 minutes ago, mob1 said:

Based on radar it could be a bit more of an eyewall meld than a true EWRC (which is sometimes common as it approaches land and the friction causes it to tighten up a bit) but it's definitely degrading which is welcome timing. 

Recon doesn't show degradation. I'm not sure what people are seeing. It's still generating very strong convection near center. It looks very steady to me.

[cardinalland]

2 minutes ago, SnoSki14 said:

Recon doesn't show degradation. I'm not sure what people are seeing. It's still generating very strong convection near center. It looks very steady to me.

This hurricane must have body insecurity issues with everything that people have said about it in the last couple of days

It looks pretty normal for a Category 3 hurricane, and unfortunately does not appear to be weakening yet

[HKY_WX]

Some of the radar hallucinations are due to attenuation. 

[mob1]

6 minutes ago, SnoSki14 said:

Recon doesn't show degradation. I'm not sure what people are seeing. It's still generating very strong convection near center. It looks very steady to me.

Radar (and the microwave pass posted above) did show some signs of degrading and possibly starting an EWRC, but radar has since improved. 

[WxWatcher007]

 

[cardinalland]

3 minutes ago, mob1 said:

Radar (and the microwave pass posted above) did show some signs of degrading and possibly starting an EWRC, but radar has since improved. 

 

Not sure about the microwave pass but radar improving is mostly an artifact of the storm entering radar range. Beam height (per RadarScope) is still about 30,000 ft near the South eyewall so it's just entering the range where the whole eyewall can be seen