Hurricane Idalia

[WxWatcher007]

Keep in mind that the HWRF is in the process of retirement so I’d look at HAFS-A/B now. 

(and that the hurricane models are prone to large errors when there isn’t a well defined LLC)

[CheeselandSkies]

2 minutes ago, WxWatcher007 said:

Keep in mind that the HWRF is in the process of retirement so I’d look at HAFS-A/B now. 

Both are much further west (central to western Panhandle) and not as strong, but B would be a solid Cat. 1 and A a mid Cat. 2 at least with 967 MB just after landfall at FH111. Like HWRF that's also a large pressure drop in the 3 hours before landfall.

[MattPetrulli]

IMO would be surprised to see a tropical storm landfall and not a hurricane landfall out of this but still super early.

[GaWx]

0Z UK: a whopping 150 miles W of the 12Z! Also, a little stronger. Comes into Fl Panhandle and then well inland in GA. This is easily the furthest west of any UK run yet:

NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER  48 HOURS
              FORECAST POSITION AT T+ 48 : 21.1N  86.2W

                        LEAD                 CENTRAL     MAXIMUM WIND
      VERIFYING TIME    TIME   POSITION   PRESSURE (MB)  SPEED (KNOTS)
      --------------    ----   --------   -------------  -------------
    0000UTC 28.08.2023   48  21.1N  86.2W     1003            26
    1200UTC 28.08.2023   60  22.2N  86.0W     1003            31
    0000UTC 29.08.2023   72  23.6N  86.2W     1003            31
    1200UTC 29.08.2023   84  25.6N  85.5W     1002            38
    0000UTC 30.08.2023   96  28.3N  85.3W      999            36
    1200UTC 30.08.2023  108  31.1N  83.7W      999            33
    0000UTC 31.08.2023  120  32.9N  82.0W      996            32
    1200UTC 31.08.2023  132  34.1N  79.4W      999            34
    0000UTC 01.09.2023  144  33.9N  77.1W     1004            39
    1200UTC 01.09.2023  156  33.1N  75.9W     1007            39
    0000UTC 02.09.2023  168  32.2N  74.5W     1007            32

[Ed, snow and hurricane fan]

I think Charley is the closest big storm I can think of, although it came through the Caribbean and was stronger on approach.  Michael as far as landfall compared to GFS ensembles, but August to October makes a deal.  If the shift W on ensembles continue, eventually Mississippi and New Orleans could wind up as areas of interest.  Euro and ensembles will be interesting.  If I wake up in the middle of the night

[CheeselandSkies]

00Z HWRF is gonna be fun...985 MB already at FH054.

Edit: Maybe not. Seems to be struggling with shear or something and still hovering in the 980s by midday Tuesday. I'm off to bed.

[yoda]

Euro keeps 93L around in the same general area from Day 6 on... then slowly moves S/SSW by Day 9 into 10

Makes landfall in the Big Bend of FL around 108 with low to mid 990s SLP 

[WxWatcher007]

Invest 93L continues to organize this morning under an ULAC.

It's very hard to get a sense of how much organization we have of the low levels without visible satellite and microwave imagery, but looking at a much longer version of IR just now, it looks like at least the mid-level circulation is developing east of the Yucatan. You can see it a bit with those towers rotating in the image above. Even if an LLC isn't under the convection currently, the consistent and strong convection we see this morning could either work to the surface with sufficient time or pull a misaligned LLC east. 

SW IR presents a similar picture. You can see a clearly consolidating circulation, but it's hard to tell if there's a true LLC and where. There may be evidence of outflow developing, another sign of organization. There has been consistent convection through the night, which has become more organized the last few hours. 

First light will be telling, but given the convective activity and appearance if this holds we probably see at least a PTC today to cover the Yucatan. 

 

[hawkeye_wx]

Even though this is looking healthier this morning, models are still slow to organize it over the next couple days as it spins over the nw Caribbean.  Then, on Monday, when it ejects northward, models are showing a digging upper trough over the gulf stretching out 93L's energy, which prevents it from doing too much until it gets into the northeast gulf.

[WxWatcher007]

8 minutes ago, hawkeye_wx said:

Even though this is looking healthier this morning, models are still slow to organize it over the next couple days as it spins over the nw Caribbean.  Then, on Monday, when it ejects northward, models are showing a digging upper trough over the gulf stretching out 93L's energy, which prevents it from doing too much until it gets into the northeast gulf.

Certainly possible, though this one looks a little ahead of the modeling schedule for organization, at least at the mid levels. Of course, any early "progress" could be lost if this slides and sits over the Yucatan today, but the eastward development of a possible vigorous MLC is intriguing. 

[WxWatcher007]

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
800 AM EDT Sat Aug 26 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 several hundred miles south of Bermuda.

Northwestern Caribbean Sea and Eastern Gulf of Mexico (AL93):
Shower and thunderstorm activity continues to show signs of 
organization in association with an area of low pressure located 
near the Yucatan Channel.  Environmental conditions appear conducive 
for further development of this system, and a tropical depression is 
likely to form within the next day or two while it moves generally 
northward over the southeastern 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...high...70 percent.
* Formation chance through 7 days...high...90 percent.

[NavarreDon]

Levi has a great video up on Tidbits from yesterday. He goes into good detail with info on LL & UL atmosphere conditions that should affect 93L’s development. 6Z GFS looks odd to me but I’m no expert. Definitely have an eye towards this here in Navarre.


.

[WxWatcher007]

First light

[Ed, snow and hurricane fan]

Does this look like it will spend much time over the Yucatan as models seem to be implying?

[MattPetrulli]

Can definitely change, but I think at the moment we’re looking at a 2016 Hurricane Hermine type storm, however this may end up being 5-10 mph stronger. I think that’s the most likely bet at the moment, not the ceiling or the floor however.


.

[cptcatz]

Best looking invest I've seen in a while. This thing could already be a tropical cyclone. 

[cptcatz]

11 minutes ago, TheGhostOfJohnBolaris said:

6z Euro a good bit west

I don't know something seems fishy to me about these model runs. Looking at how it looks on satellite right now, are we really supposed to believe it will look like this on Monday morning?

[WxWatcher007]

This longer length loop really shows the organizational trend. Far more consolidated, with continuing vigorous convection. I don't think a LLC is directly under the center of the convective canopy, but this

1) looks further organized than the guidance suggests
2) currently lies in a highly favorable environment for further development, hence the 70/90% odds
3) has a greater chance of staying offshore given the consistent convective bursts to the east of the Yucatan 

This is a good look for an invest. The more organized it becomes this weekend the more resilient it will be to shear/dry air in the Gulf. Really have to see if land interaction can disrupt this trend. 

[Windspeed]

This longer length loop really shows the organizational trend. Far more consolidated, with continuing vigorous convection. I don't think a LLC is directly under the center of the convective canopy, but this
1) looks further organized than the guidance suggests
2) currently lies in a highly favorable environment for further development, hence the 70/90% odds
3) has a greater chance of staying offshore given the consistent convective bursts to the east of the Yucatan 

This is a good look for an invest. The more organized it becomes this weekend the more resilient it will be to shear/dry air in the Gulf. Really have to see if land interaction can disrupt this trend. 

I'm not so sure an LLC hasn't consolidated under the canopy. There is some very suspicious motion in the low-level cloud field since daybreak. If a low-level vort hasn't formed, it sure looks like it's going to be genes'ing in short order today. There is also a very clearly low-level west flow just to the south and ESE of Cozumel.

[Normandy]

Morning trends make it very obvious that this is consolidating further east, and I’m  not sure what is going to drive this west into the yucatan as models are suggesting.  Still like the idea of a major hurricane into the FL peninsula somewhere near Tampa.

[schoeppeya]

Very obvious on visible there is an LLC somewhere over the channel

[CheeselandSkies]

11 minutes ago, Normandy said:

Morning trends make it very obvious that this is consolidating further east, and I’m  not sure what is going to drive this west into the yucatan as models are suggesting.  Still like the idea of a major hurricane into the FL peninsula somewhere near Tampa.

I wouldn't call it likely at this point but would be foolish to take anything off the table at this juncture.

[hawkeye_wx]

This looks like a tropical depression.  The convection was increasing overnight, but this morning it has clearly developed into a spiraling pattern, with a center just east of the northeast tip of the Yucatan.  The visible loop also clearly shows a north/northwest flow over the northeast Yucatan.

[BooneWX]

Outflow is really impressive in all quadrants. We’ve seen named storms with a much worse structure than this. 

[hawkeye_wx]

Does anyone have any thoughts about why models continue to refuse to strengthen this system at all through Monday, even though they all now show it remaining over the Caribbean and under upper ridging?

[Windspeed]

Does anyone have any thoughts about why models continue to refuse to strengthen this system at all through Monday, even though they all now show it remaining over the Caribbean and under upper ridging?

The only thing is perhaps land interaction as the ECMWF wants to shove the low inland. The GFS is also very close, meandering the low over or near to the Rivera Maya. They don't see TCG until Sunday into Monday, and it's 2-3 days before the steering flow lifts the TC northward. I think the modeling has to be taken seriously, but clearly they could be way off if TCG occurs today and the vortex remains over water.

[GaWx]

12Z UKMET: similar to 0Z with landfall E FL Panhandle and then NE well inland in GA: so two runs in a row that are the furthest NW by a large margin

NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER  24 HOURS
              FORECAST POSITION AT T+ 24 : 20.8N  86.8W

                        LEAD                 CENTRAL     MAXIMUM WIND
      VERIFYING TIME    TIME   POSITION   PRESSURE (MB)  SPEED (KNOTS)
      --------------    ----   --------   -------------  -------------
    1200UTC 27.08.2023   24  20.8N  86.8W     1005            20
    0000UTC 28.08.2023   36  20.8N  86.4W     1003            26
    1200UTC 28.08.2023   48  21.7N  86.3W     1003            29
    0000UTC 29.08.2023   60  23.1N  86.9W     1002            31
    1200UTC 29.08.2023   72  24.2N  87.0W     1002            43
    0000UTC 30.08.2023   84  26.1N  86.3W      999            36
    1200UTC 30.08.2023   96  28.8N  84.8W      996            48
    0000UTC 31.08.2023  108  31.6N  83.5W      994            36
    1200UTC 31.08.2023  120  33.5N  81.8W      997            37
    0000UTC 01.09.2023  132  34.6N  78.5W     1002            35
    1200UTC 01.09.2023  144  36.7N  74.8W     1005            39
    0000UTC 02.09.2023  156  35.9N  73.6W     1006            40
    1200UTC 02.09.2023  168  36.6N  69.7W     1006            36

[WxWatcher007]

Agree. I really think it’s land interaction at least initially.

The visible has been impressive, but look at the Cancun radar. This is a TD imo and if it’s not it’s damn close. 

 

https://bmcnoldy.earth.miami.edu/tropics/radar/

[Windspeed]

Agree. I really think it’s land interaction at least initially.

The visible has been impressive, but look at the Cancun radar. This is a TD imo and if it’s not it’s damn close. 

 
https://bmcnoldy.earth.miami.edu/tropics/radar/

I think this is a depression as well and probably will be classified this afternoon, if not certainly by 5PM. That radar imagery and the low-level cloud flow is too much to ignore. It looks like TCG literally occurred just prior or during that loop. Hopefully the NHC can get reconnaissance moved up to this evening.

As for steering flow and what this is going to do the next 24-48 hrs. Does it drift west over the Yucatan or remain over the straits? Possibly meander into the SE GOM? Huge implications over the slightest movements now we clearly have a COC.

[Normandy]

Agree with all.  No question this is a tropical cyclone and the NHC should to pull the trigger soon.  Looks too good on all levels (banding, outflow, convection, radar presentation).