Hurricane Idalia

[CoastalWx]

1 minute ago, MUWX said:

That is not intensity guidance.

I know that. Just showing that 12z guidance is available.

 

[schoeppeya]

Idalia has had a really hard time actually wrapping feeder bands into the center of the system

[CheeselandSkies]

Just now, CoastalWx said:

I know that. Just showing that 12z guidance is available.

 

I prefer to wait for the actual frame-by-frame model runs of the hurricane models (HAFS-A/B, HWRF, HMON) with MSLP, sim IR, etc.

[dan11295]

Guidance has been consistent or more or less keeping Idalia in check into shear lessen N of Cuba later tonight/early tomorrow.

[CoastalWx]

1 minute ago, CheeselandSkies said:

I prefer to wait for the actual frame-by-frame model runs of the hurricane models (HAFS-A/B, HWRF, HMON) with MSLP, sim IR, etc.

It gives you a good idea though about how things like track and intensity are changing. 

[GaWx]

2 hours ago, Hotair said:

TV reminding folks how far Ian track was from actual LF 72 hours out. I do believe the steering patterns are a little better behaved this time given the multi model consensus, but no one inside the cone should let their guard down  

 

 

 Below is a copy of a post I did 10/1/22 detailing Ian FL LF progs for 5 main op models starting from 0Z 9/25 runs, which were then 85 hours out from the Port Charlotte LF. As of 0Z today, Idalia was only ~60 hours from landfall. So, that would about correspond to the 0Z 9/26 runs for Ian.

 So, one can see from this that:

A. -Top performing UKMET <50 miles from actual Ian LF all runs within 85 hours. ~Spot on for runs that were 85, 61, 49, and 13 hours out with little net bias.

-2nd best ICON even had Tampa (70 miles too far left) just 49 hours out

-CMC was still way too far left just 25 hrs out!

-GFS not close til 25 hrs out

-Euro not close til 37 hrs out

B. Per 0Z 9/26 Ian runs, which correspond to ~how far from LF is Idalia as of 0Z today (~60 hours):

1) UKMET was spot on and ICON only 25 miles too far left

2) CMC and GFS were way up at Apalachee Bay, a whopping 250 miles too far left

3) Euro was up at Cedar Key, 160 miles too far left

4) So, non-UKMET models were all too far left with GFS, CMC, and Euro a whopping 160-250 miles too far left

5) For Idalia, models are way closer together for LF at ~60 hour point (0Z 8/28 runs):

-GFS/CMC furthest left near Perry

-ICON furthest right ~10 miles SE of Cedar Key

-So, range is only 75 miles vs 250 miles for Ian at same time from LF! GFS/CMC are furthest left like for Ian but not nearly by as much

-UKMET/Euro right in middle ~30 miles NW of Cedar Key

-Based on this, I'm guessing that 0Z GFS/CMC at Perry will verify too far left

-My best guess is to go close to 0Z UKMET/Euro, which were ~30 miles NW of Cedar Key and ~40 miles NW of 0Z ICON

 

---------------------------------

Here's the Ian FL landfall model performance post I made last year:

"Looking back to the 0Z 9/25 runs at where the models had FL landfalls:

0Z 9/25:
ICON Venice
CMC Cedar Key
GFS Destin
Euro Sarasota
UKMET Port Charlotte

12Z 9/25:
ICON Sarasota
CMC Apalachee Bay
GFS Apalachee Bay
Euro Tampa
UKMET Venice

0Z 9/26:
ICON Venice
CMC Apalachee Bay
GFS Apalachee Bay
Euro Cedar Key
UKMET Port Charlotte

12Z 9/26:
ICON Tampa
CMC Apalachicola
GFS Tampa
Euro Big Bend
UKMET Port Charlotte

0Z 9/27:
ICON Venice
CMC Big Bend
GFS Sarasota
Euro Venice
UKMET just N of Ft Myers

12Z 9/27:
ICON Port Charlotte
CMC Tampa
GFS just N of Port Charlotte
Euro Port Charlotte
UKMET 20 miles S of Ft. Myers

0Z 9/28:
ICON 15 miles S of Port Charlotte
CMC Venice
GFS Port Charlotte
Euro Port Charlotte
UKMET Port Charlotte

 My grades on FL landfall only (i.e., excluding SC landfall) for 9/25-8 runs:

UKMET A-
ICON B
Euro C-
GFS D
CMC F"

 

 

 

[Prismshine Productions]

Yeah, and notice they ticked back west...

Sent from my SM-S146VL using Tapatalk

[NERMAN]

10 minutes ago, CheeselandSkies said:

I prefer to wait for the actual frame-by-frame model runs of the hurricane models (HAFS-A/B, HWRF, HMON) with MSLP, sim IR, etc.

Totally agree. HWRF showed a strong Cat 4 at 06z and the others had a strong Cat 3. Let's see what they have at 12z before saying the guidance has dropped. 

[Windspeed]

Idalia has had a really hard time actually wrapping feeder bands into the center of the system

There is still mid-level shear imparting the circulation. That being said, the core is showing a favorable environment for continued bursts of deep convection. So it's going to be another 24 hours of give and take as bursts of convection try to wrap up shear east and then north of the center, then likely get blown back and fail to wrap from 700 to 400 hPa levels. I'd imagine this will occur repeatedly as the LLC drives just west of Cuba and into the SE GOM. Mid-level flow values won't become more favorable until well into tonight. That is when we may start seeing more alignment and more pronounced intensification on Tuesday. Eventually, into Wednesday, the flow vector will become more dangerous for significant intensification all the way into landfall, hence modeling and the official forecast.

[SnowGoose69]

3 minutes ago, Windspeed said:

20 minutes ago, schoeppeya said:

Idalia has had a really hard time actually wrapping feeder bands into the center of the system

There is still mid-level shear imparting the circulation. That being said, the core is showing a favorable environment for continued bursts of deep convection. So it's going to be another 24 hours of give and take as bursts of convection try to wrap up shear east and then north of the center, then likely get blown back and fail to wrap from 700 to 400 hPa levels. I'd imagine this will occur repeatedly as the LLC drives just west of Cuba and into the SE GOM. Mid-level flow values won't become more favorable until well into tonight. That is when we may start seeing more alignment and more pronounced intensification on Tuesday. Eventually, into Wednesday, the flow vector will become more dangerous for significant intensification all the way into landfall, hence modeling and the official forecast.

The timing of any intensification may end up not being ideal.   No doubt a massive blowup last night through today and tonight would have been better because probably an ERC would happen before landfall...it may now end up going through its peak cycle up until approach which is underrated as far as how well winds reach the surface.  A 130mph storm undergoing an ERC can cause less wind damage sometimes than a rapidly intensifying 105mph storm...we've seen this a few times in recent year.

[beanskip]

12z ICON: West

12z GFS through 51 hours: West (of its westernmost solution).

Euro still a safe bet, but it is becoming increasingly isolated to the east. 

[dan11295]

12Z GFS is basically over Tallahassee at 18Z Wednesday.

[beanskip]

CMC goes east -- basically the first model to trend that way since 18z runs yesterday. 

[NeffsvilleWx]

32 minutes ago, dan11295 said:

Guidance has been consistent or more or less keeping Idalia in check into shear lessen N of Cuba later tonight/early tomorrow.

 

You could see the sheer impact this morning as an outflow boundary from collapsing convection shot out to the east.

[NERMAN]

12z GFS came in with the same intensity as 06z, as a Cat 3

[TPAwx]

Euro remains to be seen, even with some westward movement on other guidance no reason for local TB region media mets and municipal officials to let up on messaging and urgency, esp for Zone A and B residents,

[dbullsfan]

I don’t know, seems like the Tampa bubble is in full effect her and this is gonna end up staying north and west


.

[Jersey Andrew]

4 minutes ago, TPAwx said:

Euro remains to be seen, even with some westward movement on other guidance no reason for local TB region media mets and municipal officials to let up on messaging and urgency, esp for Zone A and B residents,

After the debacle in Fort Myers last year surrounding late ordered evacuations, Tampa metro has to be very concerned about storm track and surge threat. Weren’t Zone A and B evacuated last year before Ian took a more southerly track? Tough decisions ahead.

[Hotair]

Evac orders at this time 

[Hotair]

9 minutes ago, dbullsfan said:

I don’t know, seems like the Tampa bubble is in full effect her and this is gonna end up staying north and west


.

Probably great for wind claims.  Not so much for storm surge   I don’t recall the last time we had 7 foot surge into the bay 

[GaWx]

12Z UKMET significant shift left. First, here was 0Z UKMET:

TROPICAL STORM IDALIA     ANALYSED POSITION : 19.8N  85.5W

     ATCF IDENTIFIER : AL102023

                        LEAD                 CENTRAL     MAXIMUM WIND
      VERIFYING TIME    TIME   POSITION   PRESSURE (MB)  SPEED (KNOTS)
      --------------    ----   --------   -------------  -------------
    0000UTC 28.08.2023    0  19.8N  85.5W      997            38
    1200UTC 28.08.2023   12  20.8N  84.8W      996            41
    0000UTC 29.08.2023   24  22.2N  85.5W      996            39
    1200UTC 29.08.2023   36  23.6N  85.1W      996            46
    0000UTC 30.08.2023   48  25.7N  85.1W      993            50
    1200UTC 30.08.2023   60  28.6N  83.9W      989            51
    0000UTC 31.08.2023   72  31.4N  81.8W      988            47
    1200UTC 31.08.2023   84  33.3N  78.1W      987            45
    0000UTC 01.09.2023   96  34.0N  73.6W      989            52
    1200UTC 01.09.2023  108  34.8N  70.3W      990            54
    0000UTC 02.09.2023  120  35.5N  67.8W      991            49
    1200UTC 02.09.2023  132  36.3N  65.8W      990            47
    0000UTC 03.09.2023  144  37.2N  63.7W      984            53
    1200UTC 03.09.2023  156  39.5N  60.7W      974            54
    0000UTC 04.09.2023  168  41.4N  57.5W      971            50
------------------

To compare, here is the 12Z UKMET showing a significant shift left:

TROPICAL STORM IDALIA     ANALYSED POSITION : 20.6N  85.4W

     ATCF IDENTIFIER : AL102023

                        LEAD                 CENTRAL     MAXIMUM WIND
      VERIFYING TIME    TIME   POSITION   PRESSURE (MB)  SPEED (KNOTS)
      --------------    ----   --------   -------------  -------------
    1200UTC 28.08.2023    0  20.6N  85.4W      995            41
    0000UTC 29.08.2023   12  21.5N  85.4W      995            46
    1200UTC 29.08.2023   24  23.3N  85.8W      995            43
    0000UTC 30.08.2023   36  25.3N  86.0W      994            45
    1200UTC 30.08.2023   48  27.7N  85.3W      992            48
    0000UTC 31.08.2023   60  30.2N  84.1W      987            42
    1200UTC 31.08.2023   72  32.6N  81.8W      992            43
    0000UTC 01.09.2023   84  33.6N  78.7W      998            38
    1200UTC 01.09.2023   96  34.5N  75.3W     1001            46
    0000UTC 02.09.2023  108  34.0N  72.7W     1004            44
    1200UTC 02.09.2023  120  34.9N  70.4W     1005            44
    0000UTC 03.09.2023  132  37.0N  66.5W     1003            33
    1200UTC 03.09.2023  144  36.8N  64.9W     1000            48
    0000UTC 04.09.2023  156  37.2N  62.1W      995            44
    1200UTC 04.09.2023  168  38.9N  59.8W      988            47

[CoastalWx]

I'm not in the EM workspace, but having a patchwork county evacuation scenario like that is confusing.

[TPAwx]

3 minutes ago, Jersey Andrew said:

After the debacle in Fort Myers last year surrounding late ordered evacuations, Tampa metro has to be very concerned about storm track and surge threat. Weren’t Zone A and B evacuated last year before Ian took a more southerly track? Tough decisions ahead.

Yes Ian evacs were issued for most TB coastal counties on 9/26.  
 

Really surprised Pinellas County hasn’t pulled the trigger yet, lots of folks at high risk even with current track.  MacDill AFB just went mandatory so would expect Hills and Pinellas to follow soon for Zone A.

[WxWatcher007]

 

[GaWx]

12Z UKMET landfalls ~65 miles to the NW (at Apalachee Bay) of 0Z, which was ~30 miles NW of Cedar Key 

[Derecho!]

1 hour ago, Eskimo Joe said:

GFS trying to turn Idalia back into the southeast at HR 168?

Loops back into the Gulf (never intensifies) and wanders over New Orleans at HR 222. 

[TriPol]

3 minutes ago, Derecho! said:

Loops back into the Gulf (never intensifies) and wanders over New Orleans at HR 222. 

Shades of Hurricane Elena 1985. As a former resident of Tampa, that storm was talked about A LOT in the late '80s and '90s.

[GaWx]

 With 12Z Euro still remaining, three 12Z runs shifted left vs their respective 0Z runs (UKMET, ICON, and the already tied for most left at 0Z run GFS) and one shifted right (the tied for furthest left at 0Z run CMC).

[Hotair]

Is it just me or has the northward motion stalled a bit in the last hour or so?

[GaWx]

54 minutes ago, Hotair said:

Probably great for wind claims.  Not so much for storm surge   I don’t recall the last time we had 7 foot surge into the bay 

 Hurricane Easy in 1950 (first landfall Cedar Key) produced a 6.5 foot TB surge, the largest since the 10.5 feet of 1921. At that landfall, Easy was a 958 mb cat 3 with 120 mph highest winds and was just crawling.

 Since 1950, highest surge I could find was 5 feet from H Gladys in 1968. It was a 100 mph cat 2 at landfall, which was 60 miles N of Tampa moving NE