Hurricane Idalia

[hlcater]

As the GFS now develops this system and there is 70% odds of development in the next 7 days, it's probably time for a thread on this one. It also doesn't look like the low is defined enough yet in the W carib to be designated as an invest, but when it presumably does, it'll be 93L.

[GaWx]

0Z UKMET a bit stronger (60 mph when goes offshore E US at end) (UKMET often conservative with winds as 990 mb usually corresponds to stronger TS than 50 mph) with similar to 12Z run but slight NW shift. It again landfalls in the FL Big Bend and then goes NE through SE GA and then offshore from SC:

NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER  66 HOURS
              FORECAST POSITION AT T+ 66 : 21.4N  88.3W

                        LEAD                 CENTRAL     MAXIMUM WIND
      VERIFYING TIME    TIME   POSITION   PRESSURE (MB)  SPEED (KNOTS)
      --------------    ----   --------   -------------  -------------
    0000UTC 28.08.2023   72  21.3N  87.9W     1004            22
    1200UTC 28.08.2023   84  23.4N  86.2W     1000            43
    0000UTC 29.08.2023   96  25.1N  84.9W      996            39
    1200UTC 29.08.2023  108  27.6N  84.8W      992            40
    0000UTC 30.08.2023  120  29.2N  83.9W      990            43
    1200UTC 30.08.2023  132  31.3N  82.0W      993            44
    0000UTC 31.08.2023  144  33.1N  78.5W      991            45
    1200UTC 31.08.2023  156  34.4N  74.6W      991            48
    0000UTC 01.09.2023  168  35.2N  70.6W      993            52

[GaWx]

0Z Euro ~995 mb TS landfall FL Big Bend at hour 138. Then to Jacksonville at 992 mb at 144. Heaviest rainfall 4-6" in narrow band part of N FL/SE GA.

[hawkeye_wx]

The Euro is trending toward sticking this energy over the Yucatan for 2-3 days, limiting its potential.

[WxWatcher007]

Took the GFS a while to get on board but now it essentially is. 

Now the questions are how long it takes for consolidation to occur, which obviously has significant implications on intensity in the Gulf, and how likely is this to scrape the SE coastline before likely getting kicked OTS. 

There’s vorticity, but not much in the way of convection this morning. 

https://tropic.ssec.wisc.edu/real-time/atlantic/movies/wg8vor4/wg8vor4_loop.html

 

[ineedsnow]

1 hour ago, WxWatcher007 said:

Took the GFS a while to get on board but now it essentially is. 

Now the questions are how long it takes for consolidation to occur, which obviously has significant implications on intensity in the Gulf, and how likely is this to scrape the SE coastline before likely getting kicked OTS. 

There’s vorticity, but not much in the way of convection this morning. 

https://tropic.ssec.wisc.edu/real-time/atlantic/movies/wg8vor4/wg8vor4_loop.html

 

I also wonder if the strength of future 93l will make a difference with the track of Franklin 

[40/70 Benchmark]

50 minutes ago, ineedsnow said:

I also wonder if the strength of future 93l will make a difference with the track of Franklin 

Franklin is OTS as it pertains to the US. Nothing is going to change that.

[Normandy]

Early thoughts:  vorticity seems to be setting up further east and north from the coast, leading me to think we get a stronger landfall out of this as interaction with the Yucatán might be limited.  I like the idea of a hurricane strike out of this.  Somewhere on the FL peninsula North of Miami. 

[ineedsnow]

30 minutes ago, 40/70 Benchmark said:

Franklin is OTS as it pertains to the US. Nothing is going to change that.

if models are off it can

Tropical Storm Franklin Tropical Cyclone Update
NWS National Hurricane Center Miami FL AL082023
910 AM AST Fri Aug 25 2023

...FRANKLIN MOVING ERRATICALLY SOUTHEASTWARD...

Satellite and aircraft data indicate that the center of Tropical
Storm Franklin is moving well south of the current NHC track
forecast. A southward adjustment will be made in the short term
track forecast for the upcoming regular advisory to be issued no
later than 1100 AM AST (1500 UTC).

[hawkeye_wx]

2 minutes ago, ineedsnow said:

if models are off it can

Tropical Storm Franklin Tropical Cyclone Update
NWS National Hurricane Center Miami FL AL082023
910 AM AST Fri Aug 25 2023

...FRANKLIN MOVING ERRATICALLY SOUTHEASTWARD...

Satellite and aircraft data indicate that the center of Tropical
Storm Franklin is moving well south of the current NHC track
forecast. A southward adjustment will be made in the short term
track forecast for the upcoming regular advisory to be issued no
later than 1100 AM AST (1500 UTC).

I was going to mention this.  Models had it moving northeastward this morning, but instead it's moving southeastward.

[ineedsnow]

6 minutes ago, hawkeye_wx said:

I was going to mention this.  Models had it moving northeastward this morning, but instead it's moving southeastward.

https://www.tropicaltidbits.com/sat/satlooper.php?region=08L&product=vis

[40/70 Benchmark]

1 hour ago, ineedsnow said:

if models are off it can

Tropical Storm Franklin Tropical Cyclone Update
NWS National Hurricane Center Miami FL AL082023
910 AM AST Fri Aug 25 2023

...FRANKLIN MOVING ERRATICALLY SOUTHEASTWARD...

Satellite and aircraft data indicate that the center of Tropical
Storm Franklin is moving well south of the current NHC track
forecast. A southward adjustment will be made in the short term
track forecast for the upcoming regular advisory to be issued no
later than 1100 AM AST (1500 UTC).

Good luck.

This thing has been gone for days...the forecast track is never perfect, but it doesn't change the fact there is nothing to pull it up here.

[WxWatcher007]

Even though the motion has been erratic, the second trough is a virtual lock to kick this northeast later in the period, much like the current W. Caribbean AOI. 

It would take a medium range guidance bust of historic proportions—across all guidance for Franklin to become a threat to the US. Atlantic Canada should certainly pay close attention, however. 

[nwohweather]

That big ole High Pressure there is playing some serious defense for the CONUS on the models

[GaWx]

It looks like this will likely be Invest 93L shortly.

 Based on how the models did with Ian last year, I'll be paying somewhat extra attention to the UKMET. The reason is that it did the best by a good margin for Ian last year in having runs a good number of days out with a SW FL instead of Tampa or further north landfall. The bulk of other models had Tampa north until much closer to landfall. ICON was second best although back a ways.

[WxWatcher007]

GFS still playing catch up with a faster consolidating low. Still pretty broad lifting into the Gulf at 84. Going to be stronger though as it tightens in the Gulf.

[WxWatcher007]

GFS quite a bit stronger with a further west track between 84 and 108.

[mob1]

Went from almost nothing to this is a few runs 

[WxWatcher007]

Very different, but it's one run. Let's see how much the ensembles follow the op. It's a very different intensity and steering forecast. One thing is clear, however, it has been trending toward something more consolidated as it lifts into the Gulf. Here are the last 9 runs. 

 

[GaWx]

12Z UKMET: track is SE of 0Z run but still landfalls near FL Big Bend; then moves NE to off the SE US; still a TS but a bit weaker than 0Z run due maybe to the further SE track (keep in mind UKMET is often conservatively low with winds):

NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER  84 HOURS
              FORECAST POSITION AT T+ 84 : 23.2N  85.4W

                        LEAD                 CENTRAL     MAXIMUM WIND
      VERIFYING TIME    TIME   POSITION   PRESSURE (MB)  SPEED (KNOTS)
      --------------    ----   --------   -------------  -------------
    0000UTC 29.08.2023   84  23.2N  85.4W     1005            31
    1200UTC 29.08.2023   96  25.8N  83.9W     1002            38
    0000UTC 30.08.2023  108  28.3N  82.7W      999            32
    1200UTC 30.08.2023  120  31.7N  80.4W     1000            34
    0000UTC 31.08.2023  132  32.8N  77.9W     1000            35
    1200UTC 31.08.2023  144  33.9N  74.5W     1000            32
    0000UTC 01.09.2023  156  34.3N  71.9W     1001            39
    1200UTC 01.09.2023  168  34.2N  69.2W     1002            36
 

[NorthHillsWx]

Since Michael, I will never take a storm forming like this lightly regardless of initial model intensity. I actually think this has a higher ceiling than what models are showing. This isn’t that dissimilar situation from what led to Michael doing what it did. If this consolidates in the NW Caribbean before entering the Gulf, watch out

[GaWx]

- This is now Invest 93L.

- 12Z ICON 991 mb landfall (strongest run yet) in the Big Bend

[ineedsnow]

59 minutes ago, 40/70 Benchmark said:

Good luck.

This thing has been gone for days...the forecast track is never perfect, but it doesn't change the fact there is nothing to pull it up here.

i know that.. I always just hope the models miss something lol  

[WxWatcher007]

[ineedsnow]

7 minutes ago, WxWatcher007 said:

starting to look better.. 

[WxWatcher007]

2 minutes ago, ineedsnow said:

starting to look better.. 

Well I think we'll have to see what kind of consolidation and organization there is in the next 24-48 hours, and how much a consolidating low gets over the Yucatan. The analysis above has it a little more consolidated than I would have expected thus far but it still has a ways to go IMO.  

[Windspeed]

Wow, that nascent low-level circulation looks to be consolidating much further east than modeled. That may keep this off the Yucatan entirely as the disturbance continues to evolve.

[NorthHillsWx]

Once this gets going I don’t really see a major hindrance to strengthening other than land. The shear vector is favorable, it’s going over nuclear fuel in the gulf, and it might get a bit of an boost from the upper level jet offering optimal ventilation. Dry air in western gulf could be an issue but if this wraps up quick these Caribbean storms have shown to be less susceptible to that unless hit with NW shear. I think the next 24-36 hours tell the tale of how strong this will get as it is entirely dependent on how fast it can ramp up before landfall 

[WxWatcher007]

Thought we'd see 40/80 at 2pm. A lot of clues in this one. 

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
200 PM EDT Fri Aug 25 2023

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

Active Systems:
The National Hurricane Center is issuing advisories on Tropical 
Storm Franklin, located a couple of hundred miles east of the Turks 
and Caicos Islands. 

Northwestern Caribbean Sea and eastern Gulf of Mexico (AL93):
Satellite images indicate that the area of low pressure over the 
northwestern Caribbean Sea is gradually becoming better organized, 
with increasing thunderstorm activity and a better-defined 
low-level circulation.  Environmental conditions appear conducive 
for further development during the next several days, and a 
tropical depression is likely to form late this weekend or early 
next week while it moves generally northward over the eastern Gulf 
of Mexico.  Interests in the Yucatan Peninsula of Mexico, western 
Cuba, and Florida should monitor the progress of this system.
* Formation chance through 48 hours...medium...40 percent.
* Formation chance through 7 days...high...80 percent.

 

[CheeselandSkies]

1 hour ago, NorthHillsWx said:

Since Michael, I will never take a storm forming like this lightly regardless of initial model intensity. I actually think this has a higher ceiling than what models are showing. This isn’t that dissimilar situation from what led to Michael doing what it did. If this consolidates in the NW Caribbean before entering the Gulf, watch out

Somebody gets it.