Hurricane Idalia

[WxWatcher007]

First VDM from mission 5. No eye observed at this time. 

 

Product: Air Force Vortex Message (URNT12 KNHC)
Transmitted: 28th day of the month at 11:59Z
Agency: United States Air Force
Aircraft: Lockheed WC-130J Hercules with reg. number AF99-5309
Storm Name: Idalia
Storm Number & Year: 10 in 2023 (flight in the North Atlantic basin)
Mission Number: 5
Observation Number: 05 ( See all messages of this type for this mission. )

A. Time of Center Fix: 28th day of the month at 11:18:10Z
B. Center Fix Coordinates: 20.61N 85.17W
B. Center Fix Location: 115 statute miles (185 km) to the ESE (109°) from Cancún, Quintana Roo, Mexico.
C. Minimum Height at Standard Level: 1,351m (4,432ft) at 850mb
D. Minimum Sea Level Pressure: 990mb (29.24 inHg)
E. Dropsonde Surface Wind at Center: From 125° at 12kts (From the SE at 14mph)
F. Eye Character: Not Available
G. Eye Shape: Not Available
H. Estimated (by SFMR or visually) Maximum Surface Wind Inbound: 35kts (40.3mph)
I. Location & Time of the Estimated Maximum Surface Wind Inbound: 23 nautical miles (26 statute miles) to the WNW (300°) of center fix at 11:11:00Z
J. Maximum Flight Level Wind Inbound: From 24° at 37kts (From the NNE at 42.6mph)
K. Location & Time of the Maximum Flight Level Wind Inbound: 17 nautical miles (20 statute miles) to the WNW (294°) of center fix at 11:13:00Z
L. Estimated (by SFMR or visually) Maximum Surface Wind Outbound: 57kts (65.6mph)
M. Location & Time of the Estimated Maximum Surface Wind Outbound: 26 nautical miles (30 statute miles) to the SE (128°) of center fix at 11:27:00Z
N. Maximum Flight Level Wind Outbound: From 191° at 56kts (From between the S and SSW at 64.4mph)
O. Location & Time of the Maximum Flight Level Wind Outbound: 59 nautical miles (68 statute miles) to the SE (132°) of center fix at 11:39:00Z
P. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 20°C (68°F) at a pressure alt. of 1,530m (5,020ft)
Q. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 22°C (72°F) at a pressure alt. of 1,530m (5,020ft)
R. Dewpoint Temp (collected at same location as temp inside eye): 16°C (61°F)
R. Sea Surface Temp (collected at same location as temp inside eye): Not Available
S. Fix Determined By: Penetration, Wind and Pressure
S. Fix Level: 850mb
T. Navigational Fix Accuracy: 0.02 nautical miles
T. Meteorological Accuracy: 3 nautical miles

Remarks Section:
 

Maximum Flight Level Wind: 56kts (~ 64.4mph) which was observed 59 nautical miles (68 statute miles) to the SE (132°) from the flight level center at 11:39:00Z
Maximum Flight Level Temp: 23°C (73°F) which was observed 11 nautical miles (13 statute miles) to the WNW (289°) from the flight level center

[WxWatcher007]

Mission 6 extrapolated down to 983.9mb but again, the caveat is that this was extrapolated at ~12,000ft. Nothing earth shattering about FL winds or SFMR so this is probably too low. Dropsonde would confirm. 

Stepping away for a bit unless there's something really interesting.  

[Hotair]

Satellite is suggestive of Idalia forming an eye .  

[CoastalWx]

Still has that elongated area of convection from SSW-NNE.  It has some work to do still as far as organization.

[Hotair]

NOAA3 

 

 

[WxSynopsisDavid]

29 minutes ago, Hotair said:

Satellite is suggestive of Idalia forming an eye .  

Negative. The cloud tops are casting a shadow that is given the appearance of an eye. No eye is developing yet, according to recon.

[Boston Bulldog]

Not quite sure where the shear is decreasing narrative has come from. Currently the storm is dealing with moderate shear which is tilting the core despite the strong convection. We've observed several wrap up attempts that have failed so far, which is likely due to this ~15-20kts of shear, and some dry air still showing up around 800 hPa on dropsonde data.

There has been no observed decrease in vertical wind shear over the past 24 hours ahead of the system or over the system.

Idalia will remain under similar conditions as it lifts into the gulf. We may see a period of little to no shear as the flow switches direction while the tough approaches (likely when we will see the strongest chance for RI). From there the trough will begin to increase vertical shear again, this time southerly. However, favorable synoptic interaction with the equatorward entrance region of the jet streak that will be traversing the eastern US at this time will likely offset the negative effects of this southerly shear as Idalia approaches landfall thanks to diffluence.

Just speculating here, but I wonder if this southerly shear and dry air behind the system at landfall would eat away at the back eyewall upon approach, as we have seen with so many other gulf "halficane" landfalls in recent years

EDIT: Fixed poleward to equatorward

[beanskip]

2 minutes ago, Boston Bulldog said:

Not quite sure where the shear is decreasing narrative has come from. Currently the storm is dealing with moderate shear which is tilting the core despite the strong convection. We've observed several wrap up attempts that have failed so far, which is likely due to this ~15-20kts of shear, and some dry air still showing up around 800 hPa on dropsonde data.

http://tropic.ssec.wisc.edu/real-time/atlantic/winds/wg8shr.GIF

There has been no observed decrease in vertical wind shear over the past 24 hours ahead of the system or over the system.

http://tropic.ssec.wisc.edu/real-time/atlantic/winds/wg8sht.GIF

Idalia will remain under similar conditions as it lifts into the gulf. We may see a brief period of little to no shear as the flow switches direction while the tough approaches (likely when we will see the strongest chance for RI). From there the trough will begin to increase vertical shear again, this time southerly. However, favorable synoptic interaction with the poleward entrance region of the jet streak that will be traversing the eastern US at this time will likely offset the negative effects of this southerly shear as Idalia approaches landfall thanks to diffluence.

Just speculating here, but I wonder if this southerly shear and dry air behind the system at landfall would eat away at the back eyewall upon approach, as we have seen with so many other gulf "halficane" landfalls in recent years

This is excellent. To wit, it does not appear the pressure is dropping per latest recon pass.

 

[Hotair]

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  

 

 

[eyewall]

5 minutes 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  

 

 

Yeah Charlie ended up farther down the coast too like that.

[beanskip]

1 minute ago, eyewall said:

Yeah Charlie ended up farther down the coast too like that.

Is there history on the direction of this miss. These two examples are both to the right -- is that a known bias or just a coincidence for these two?

[Hotair]

Euro ensembles from @HurricanesJames show tight overlap. 

[Retrobuc]

4 minutes ago, beanskip said:

Is there history on the direction of this miss. These two examples are both to the right -- is that a known bias or just a coincidence for these two?

I feel like most storms have moved east, but that's just a feel, nothing quantitative

[Derecho!]

Last NOAA Dropsonde is labeled "SE Eyewall"

 

 

[beanskip]

17 minutes ago, Hotair said:

Euro ensembles from @HurricanesJames show tight overlap. 

Would love to see the op run plotted on there.

[Boston Bulldog]

3 minutes ago, Derecho! said:

Last NOAA Dropsonde is labeled "SE Eyewall"

 

 

Now sonde #9 is labeled as in the eye. VDM will be telling

[Eskimo Joe]

 

[STILL N OF PIKE]

Is the storm becoming less vertically tilted Or *when is it forecast to be * because until that gets sorted, strengthening is almost always slow/steady in my experiences 

[PackGrad05]

There is still a decent amount of spread in the ensembles (both EPS and GEFS) with regards to impacts on the SE coast.   The exact track will determine impacts not only at the coast, but inland.  
 

[cptcatz]

Just putting this model image out there, from August 20, eight days ago, for this exact time stamp.  Compare to current satellite...this is why Euro always reigns supreme.

[hawkeye_wx]

Models mostly predicted this system would have issues until it got into the gulf Monday night and Tuesday.  It has done well to get down to 990 mb, but, as others have noted, it has yet to be able to wrap the convection around the surface center.  It continues to try, but so far it's just a series of strong cells trying hard to hold onto the center while being pushed back south/southeast by some dry, shearing flow.

[CoastalWx]

24 minutes ago, cptcatz said:

Just putting this model image out there, from August 20, eight days ago, for this exact time stamp.  Compare to current satellite...this is why Euro always reigns supreme.

Just 50mb off for Franklin.

[cptcatz]

1 minute ago, CoastalWx said:

Just 50mb off for Franklin.

lol well Euro always has trouble with intensity.  But this is when GFS was seeing nada in the Caribbean.

[CoastalWx]

Just now, cptcatz said:

lol well Euro always has trouble with intensity.  But this is when GFS was seeing nada in the Caribbean.

Yeah GFS missed Idalia.

[beanskip]

Well, I know we're not supposed to talk about the NAM for tropics -- or much of anything else -- but it is showing a pretty striking trend to the west and slower on its 12z run. Given that King Euro crept west at Oz and the hurricane models did at 6z, I think something might be going on here.

[TPAwx]

As 12z suite comes in, thinking about the ~50 n mi average track error at 48h

[PackGrad05]

With so many consistent moves to the east, a move back west wouldn't be surprising at this point.  It's really going to depend on the speed and the trough strength to the north.

[WxWatcher007]

18 minutes ago, CoastalWx said:

Yeah GFS missed Idalia.

Which is surprising considering the GFS loves to spin up anything coming from a CAG. Completely missed the signal. 
 

13 minutes ago, TPAwx said:

As 12z suite comes in, thinking about the ~50 n mi average track error at 48h

Probably a nail biter to the end. Good thing is that the steady northward movement now should help smooth out any stall related hiccups we may have seen on track guidance. 
 

1 minute ago, PackGrad05 said:

With so many consistent moves to the east, a move back west wouldn't be surprising at this point.  It's really going to depend on the speed and the trough strength to the north.

Agree. I don’t think we see a major shift at this point, but as the NHC says, the parallel movement up the west coast of Florida means any deviation has a major impact. Would not be surprised if this entered the Atlantic as a minimal hurricane if it comes into Florida south enough. 

[shaggy]

2 minutes ago, PackGrad05 said:

With so many consistent moves to the east, a move back west wouldn't be surprising at this point.  It's really going to depend on the speed and the trough strength to the north.

With her reluctance to move north in wonder if we get into a scenario where the trough leaves her behind a little as the models are hinting at just offshore. 

For practical impacts along the east coast inwonder if a slight miss by the trough equals less east turn and we see a closer to the coast track say Charleston to lookout or so?

[yoda]

Still 65mph at 11