Hurricane Michael

Kermit.de.frog

Now a Category 1 hurricane approaching the Gulf of Mexico

Latest guidance

Key Messages:

1. Michael is forecast to be a dangerous major hurricane when it
reaches the northeastern Gulf Coast on Wednesday, and life-
threatening storm surge is possible along portions of the Florida
Gulf Coast regardless of the storm's exact track or intensity.
Residents in the storm surge and hurricane watch areas should follow
any advice given by local officials, as storm surge and hurricane
warnings will likely be issued later today.

2. Heavy rainfall from Michael could produce life-threatening flash
flooding from the Florida Panhandle and Big Bend region into
portions of the Carolinas through Thursday.

3. Hurricane conditions will spread over portions of western Cuba
this afternoon, where a hurricane warning is now in effect.
Tropical storm conditions are expected over the northeastern Yucatan
Peninsula and the Isle of Youth today.

4. Michael is expected to produce heavy rainfall and flash flooding
over portions of western Cuba and the northeastern Yucatan Peninsula
of Mexico during the next couple of days.

FORECAST POSITIONS AND MAX WINDS

INIT 08/1500Z 21.2N 84.9W 65 KT 75 MPH
12H 09/0000Z 22.6N 85.3W 85 KT 100 MPH
24H 09/1200Z 24.4N 85.9W 95 KT 110 MPH
36H 10/0000Z 26.4N 86.4W 105 KT 120 MPH
48H 10/1200Z 28.6N 86.1W 105 KT 120 MPH
72H 11/1200Z 33.0N 82.5W 45 KT 50 MPH...INLAND
96H 12/1200Z 37.8N 73.6W 50 KT 60 MPH...POST-TROP/EXTRATROP
120H 13/1200Z 42.8N 59.0W 55 KT 65 MPH...POST-TROP/EXTRATROP

Expect this to be literally a fast moving situation.

Expected to become a major Category 3 (conceivably higher depending on the rate of intensification and prime conditions in the Gulf) hurricane in the next 24 - 36 hours.








Infra red

https://www.tropicaltidbits.com/sat/satlooper.php?region=14L&product=ir

Aircraft Recon

https://www.tropicaltidbits.com/recon/

sdanseo

Not impossible for this to get to Cat 5. 18hrs ago NHC were predicting max 85kt. SSTs are very warm in the gulf and Caribbean.

Latest SHIPS forecast indicating 81 kts nearing landfall sometime Wednesday evening.

ftp://ftp.nhc.noaa.gov/atcf/stext/18100818AL1418_ships.txt

dfx-

Wind shear was supposed to be the saviour?

Gaoth Laidir

It won't make CAT 3. I'd say the SHIPS has it bang on at around 80-85 kts max. It will completely miss the pool of highest ocean heat content in the middle of the Gulf, so another 15-20 knots or so as it leaves the warmest waters around Cuba will probably be the highest it will get. But it will be interesting to see if the NHC overstate it again. They've gone for the very top of the intensity guidance envelope. They've also analysed it at 70 knots at 18Z despite max SFMR winds of 54 kts around then.

dfx-

dfx- wrote: »

Wind shear was supposed to be the saviour?

Could yet be. 13-16 kts of shear up to landfall.


TIME (HR) 0 6 12 18 24 36 48 60 72 84 96 108 120

V (KT) NO LAND 70 75 77 79 80 80 81 77 74 68 67 57 38

V (KT) LAND 70 75 77 79 80 80 81 46 33 29 30 21 DIS

V (KT) LGEM 70 75 79 80 80 81 82 46 33 29 35 35 29

SHEAR (KT) 15 16 22 16 13 16 16 18 17 31 49 71 69

ninebeanrows

Gaoth Laidir wrote: »

It won't make CAT 3. I'd say the SHIPS has it bang on at around 80-85 kts max. It will completely miss the pool of highest ocean heat content in the middle of the Gulf, so another 15-20 knots or so as it leaves the warmest waters around Cuba will probably be the highest it will get. But it will be interesting to see if the NHC overstate it again. They've gone for the very top of the intensity guidance envelope. They've also analysed it at 70 knots at 18Z despite max SFMR winds of 54 kts around then.

EC has it @ 947hPa and near 140knots close to landfall

Gaoth Laidir

Sleety_Rain wrote: »

EC has it @ 947hPa and near 140knots close to landfall

140 knots? You mean kph. 165 kph sustained on this

https://weather.us/model-charts/euro/florida/wind-streamlines/20181010-2100z.html

ninebeanrows

Looking at 159mph gust here.

Gaoth Laidir

Sleety_Rain wrote: »

The intensity is done on gusts no?

No, sustained winds. The NHC use 1-minute mean sustained, which is usually around 10% higher than the standard 10-minute mean.

ninebeanrows

Gaoth Laidir wrote: »

No, sustained winds. The NHC use 1-minute mean sustained, which is usually around 10% higher than the standard 10-minute mean.

I see that now- had forgotten briefly:pac:- although going on experience they seem to go with intensity near the maximum flight level winds they sample.

I'd love to see verification against the recorded sustained winds versus the forecast sustained winds versus the recorded gusts!

I would think that the recorded max gust is nearer the the forecast sustained wind or less

Gaoth Laidir

Sleety_Rain wrote: »

I see that now- had forgotten briefly:pac:- although going on experience they seem to go with intensity near the maximum flight level winds they sample.

I'd love to see verification against the recorded sustained winds versus the forecast sustained winds versus the recorded gusts!

I would think that the recorded max gust is nearer the the forecast sustained wind or less

They have a reduction factor for calculating surface winds from flight level winds, which is usually around 15-20%.

In my experience the reported speeds are nearly always less than forecast, especially for US-landfalls. The 1-minute sustained winds quoted by the NHC will be closer to the gusts as they are averaged over only 1 minute, in which time one decent gust will up the value. Remember that they're always the MAXIMUM sustained values, so there will also be other periods much lower than that too. That's why from an academic point of view the 10-minute speeds are more relevant, but for talking of potential damage the 1-minute are used.

Gaoth Laidir

Scan at 2136Z shows the deep convection has pretty much formed an eye.

M.T. Cranium

Storm surge is probably the biggest concern given the flat nature of the Florida panhandle coastline and the timing (new moon is just occurring now). I do think it has some potential to strengthen to a major hurricane even though it misses that warmest pool of Gulf water, as it has done quite well organizing in a less than perfect situation between Yucatan and Cuba. Ocean buoy 42003 will be right in its path around 18z today.

https://www.ndbc.noaa.gov/station_page.php?station=42003

This link includes frequent updates and (during local daylight hours) pictures of the waves and sky conditions. Could get interesting by 15z. Current wind speeds around 30 to 50 knots. This buoy could be in the forward eyewall at some point.

Gaoth Laidir

Michael is now leaving the area of very high ocean heat content that allowed it to intensify yesterday and will cross a very shallow pool over the next 12-24 hours. After that it remains away from the warmest waters.

Kermit.de.frog

Definitely intensifying at the moment. A lot more of a symmetrical structure now, less shear and the circulation is a lot clearer. The eyewall should become better defined in the next few hours.

100 mph recorded on the eastern eyewall at last recon. That makes it a Cat 2 at next update.

The hashing of the cloudtops on the northwest side is classic sign of intensification.



https://www.tropicaltidbits.com/sat/satlooper.php?region=14L&product=ir

Itssoeasy

I know someone from that area of Florida. I might check and see how they are prepared. This storm seemed to spring up faster then normal.

sdanseo

Itssoeasy wrote: »

I know someone from that area of Florida. I might check and see how they are prepared. This storm seemed to spring up faster then normal.

It's down to where it started..barely 1,000km from Florida as opposed to more like 8,000km east. It just had no distance to travel in comparison.

Considerable upgrade on the SHIPS forecast compared to this time yesterday evening.

18Z forecast is for 106 kts (just over 120 mph) when 47km from land at +24 hrs. Shear is 9 kts.

Gaoth Laidir

[Deleted User] wrote: »

Considerable upgrade on the SHIPS forecast compared to this time yesterday evening.

18Z forecast is for 106 kts (just over 120 mph) when 47km from land at +24 hrs. Shear is 9 kts.

It's not correct as it's taking its initial intensity as 105t knots, which is way above the 95 knots current intensity. It will rerun soon with this correct starting figure which will then bring all forecast points down too.

The max aircraft winds measured are below 90 knots yet the NHC have it as 95 again. Maybe Nathan Rao now works there.

Gaoth Laidir

Gaoth Laidir wrote: »

It's not correct as it's taking its initial intensity as 105t knots, which is way above the 95 knots current intensity. It will rerun soon with this correct starting figure which will then bring all forecast points down too.

The max aircraft winds measured are below 90 knots yet the NHC have it as 95 again. Maybe Nathan Rao now works there.

Well spotted! Why would such an error be made I wonder?

12Z starts at 90 kts with a forecast 96 kts at +24 hrs.

Gaoth Laidir

[Deleted User] wrote: »

Well spotted! Why would such an error be made I wonder?

12Z starts at 90 kts with a forecast 96 kts at +24 hrs.

The 12Z actually first ran with 95 initial intensity today before it reran with the NHC updated 90 kts a little while later. Not sure why it does that. I hadn't spotted it before today so maybe just a glitch.

Gaoth Laidir

There's a glitch somewhere alright. The early 18Z intensity runs have the 105-kt starting point. The NHC definitely had it at 95 kts in their 18Z update.

Disregard this chart.

Kermit.de.frog

Eye wall fully closed now with intense cells developing along the southeast wall.



Little doubt it is intensifying and has already gone through one eye wall replacement cycle.

Next aircraft recon underway.

https://www.tropicaltidbits.com/recon/

Gaoth Laidir

Kermit.de.frog wrote: »

Eye wall fully closed now with intense cells developing along the southeast wall.



Little doubt it is intensifying and has already gone through one eye wall replacement cycle.

Next aircraft recon underway.

https://www.tropicaltidbits.com/recon/

It hasn't really ever developed an proper eye so it couldn't go through a cycle. Microwave scans so far have shown it never really fully closed. It's not a classic hurricane yet and may still be struggling over that cooler water. I reckon it won't intensify much more, though I'd still expect the NHC to go for Cat 3. I think their forecasts are too high and have been for the past 24 hours. The highest measured wind was a very localised 91 knots earlier, but the bulk of the data show below 90 kts.

Gaoth Laidir

18Z multiplatform wind measurements (max wind 88 kts).



Aircraft data (max 80 kts, a little low).

Kermit.de.frog

It had a well defined eye 3 hours a go though not completely closed. The circulation appears to be now completely closed with only some weakness left on the western side.

Latest recon should show it has both deepened and strengthened.

Be surprised if it didn't.

Gaoth Laidir

Still slight opening in the sw eyewall in the latest 37GHz at 19.30Z but the 89GHz shows it more fragmented at higher levels. The recon data will be interesting alright. I'd be surprised if it finds any 95+ values.

Kermit.de.frog

Now a major Category 3 hurricane according to the latest NOAA update.

Pressure 957 mbs, 120 mph sustained, Gusts 150 mph

Kermit.de.frog

Now down to 955 mbs.

Recon mission 11 reported a closed eye wall so assuming no ingestion of dry air should be all systems go to intensify further.

Looking impressive now on infrared

https://www.tropicaltidbits.com/sat/satlooper.php?region=14L&product=ir

Gaoth Laidir

Three planes currently in the storm, all consistently reporting max 90-kt SFMR winds, yet the NHC raise it to 105 kts! They quote the highest flight level wind was only 109 kts, which would normally yield a surface wind of 90-95 kts, yet this time they're not applying that reduction factor at all. I knew they'd overdo it as always, but not by that much. I'm baffled at why they do this.

Kermit.de.frog

Current status - Mission 12



Notable intensification here. It's kicking off fast.




Really impressive infrared.

Kermit.de.frog

Gaoth Laidir wrote: »

Three planes currently in the storm, all consistently reporting max 90-kt SFMR winds, yet the NHC raise it to 105 kts! They quote the highest flight level wind was only 109 kts, which would normally yield a surface wind of 90-95 kts, yet this time they're not applying that reduction factor at all. I knew they'd overdo it as always, but not by that much. I'm baffled at why they do this.

They told us. They want to be "generous".

Kermit.de.frog

124 kt flight level wind just recorded on mission 12

https://www.tropicaltidbits.com/recon/


Currently this is evolving in to a potential Category 4 strength hurricane and it's happening fast.


The eye is now surrounded by deep convection.

hatrickpatrick

Massive rapid intensification going on in the latest satellite loops. Check out that burst of activity to the North of the eye:

https://i.imgur.com/L8D0jiQ.gifv

Kermit.de.frog

DVORAK has it now at 115 kts. Which would make it a Category 4 hurricane.

Itssoeasy

Kermit.de.frog wrote: »

124 kt flight level wind just recorded on mission 12

https://www.tropicaltidbits.com/recon/


Currently this is evolving in to a potential Category 4 strength hurricane and it's happening fast.


The eye is now surrounded by deep convection.

So is this looking bad or is as you said above Kermit "being generous" ?

I spoke to my friend in florida and they have got food and water and animals sorted and the "important stuff saved" which I'm taking to mean documents and important stuff they don't want damaged by water as they aren't right on the coast of the panhandle but they aren't that far away and are near a waterway.

Rikand

Kdf vs gl is the highlight of this thread for me so far

Kermit.de.frog

Itssoeasy wrote: »

So is this looking bad or is as you said above Kermit "being generous" ?

No not being generous, these are actual obs from the aerial recon.

You can view the data as it comes in here. There are two flights currently in progress - Missions 12 and 11

https://www.tropicaltidbits.com/recon/

It's probably a Category 4 hurricane now.

igCorcaigh

https://twitter.com/EricHolthaus/status/1049809138920955905?s=19

Kermit.de.frog

Eye clearing out. Deep convection surrounding the eye wall. Almost certainly Category 4 now based on obs as well. That's "Anderson Cooper" on the CNN hurricane scale, Wolf Blitzer doesn't get out of bed for any less than a Cat 5.

Mission 11's latest pass (just after 2330Z) through the core had SFMR winds of 90 kts.

Kermit.de.frog

Deleted User wrote: »

Mission 11's latest pass (just after 2330Z) through the core had SFMR winds of 90 kts.

Data missing from the flight just as they were approaching the eye. They had to divert before hand too as they could not go through the tower cloud tops.


Latest from mission 12 is a flight level speed now of 127 kts.

Kermit.de.frog

Latest mission aerial pass just now shows surface pressure @ 948.5 mb and indicative surface wind speed of 127 mph.

Flight level speed recorded @ 131 kts.

It's near a Category 4 on that surface speed but in reality probably already is.

00Z SHIPS forecast



The +18 hrs column are the predicted conditions 18km from landfall.

Gaoth Laidir

I have to say it's deepened a lot more than I expected. I was originally thinking 85-ish. The highest SFMR wind so far has been 105 kts (the 110 kts at 03:55Z was unreliable). Mission 13 has just found another 105 kts in the NW eyewall 15 mins ago below a flight level wind of 135 kts. Will it reach CAT 4 (>113 kts)? Need to see the eastern and northeastern eyewall values, but hopefully it won't strengthen any more.

M.T. Cranium

They just indicated it has reached 130 mph cat-4 status, but I think the analysis you showed can be taken as the reason why it didn't go to a full-on cat-5 given some of the other factors in play. Whether it stays at cat-4 to landfall remains to be seen but in terms of wind impacts, it would be a lot less disruptive if it chose south rather than directly over Panama City, as population is rather sparse in comparison to the south (although a few smaller towns in harm's way). The surge will definitely be a big problem a lot further afield as most of the raised water levels will have to go east rather than west of Cape San Blas.

Gaoth Laidir

123-knot surface winds found at 07:23Z. Shít's got real.

pad199207

Winds up to 140mph now

PokeHerKing

Gaoth Laidir wrote:

123-knot surface winds found at 07:23Z. Shít's got real.

GL is onboard the hype train! #pray4panhandle

Akrasia

Seriously dangerous situation developing now. Governor Rick Scott and President Trump have said they're fully prepared. I hope they're right