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Hurricane Michael

  • 08-10-2018 5:12pm
    #1
    Registered Users Posts: 21,821 ✭✭✭✭ 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.

    153129_5day_cone_no_line_and_wind.png



    hurricane-wind-scale-look-bermuda-cat-1-74-95-mph-cat-4525517.png


    Infra red

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

    Aircraft Recon

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


«13456

Comments

  • Registered Users Posts: 9,183 ✭✭✭ 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.


  • Registered Users Posts: 4,443 ✭✭✭ 17-pdr


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

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


  • Moderators, Sports Moderators Posts: 15,539 Mod ✭✭✭✭ dfx-


    Wind shear was supposed to be the saviour?


  • Registered Users Posts: 8,202 ✭✭✭ 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.

    2018AL14_OHCNFCST_201810081200.GIF


  • Registered Users Posts: 4,443 ✭✭✭ 17-pdr


    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


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  • Registered Users Posts: 12,653 ✭✭✭✭ ninebeanrows


    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.

    2018AL14_OHCNFCST_201810081200.GIF

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


  • Registered Users Posts: 8,202 ✭✭✭ Gaoth Laidir


    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


  • Registered Users Posts: 12,653 ✭✭✭✭ ninebeanrows


    Looking at 159mph gust here.


  • Registered Users Posts: 8,202 ✭✭✭ Gaoth Laidir


    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.


  • Registered Users Posts: 12,653 ✭✭✭✭ ninebeanrows


    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


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  • Registered Users Posts: 8,202 ✭✭✭ Gaoth Laidir


    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.


  • Registered Users Posts: 8,202 ✭✭✭ Gaoth Laidir


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

    20181008.2136.gpm.x.colorpct_89h_89v_1deg.14LMICHAEL.70kts-978mb-217N-851W.036pc.jpg


  • Registered Users Posts: 13,215 ✭✭✭✭ 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.


  • Registered Users Posts: 8,202 ✭✭✭ 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.

    463313.jpg


  • Registered Users Posts: 21,821 ✭✭✭✭ 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


  • Registered Users Posts: 37,343 ✭✭✭✭ 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.


  • Registered Users Posts: 9,183 ✭✭✭ 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.


  • Registered Users Posts: 4,443 ✭✭✭ 17-pdr


    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.


  • Registered Users Posts: 8,202 ✭✭✭ Gaoth Laidir


    17-pdr 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.


  • Registered Users Posts: 4,443 ✭✭✭ 17-pdr


    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.


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  • Registered Users Posts: 8,202 ✭✭✭ Gaoth Laidir


    17-pdr 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.


  • Registered Users Posts: 8,202 ✭✭✭ 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.

    aal14_2018100918_intensity_early.png


  • Registered Users Posts: 21,821 ✭✭✭✭ Kermit.de.frog


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

    goes16_ir_14L_201810092003.jpg?25.5273.6

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

    Next aircraft recon underway.

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


  • Registered Users Posts: 8,202 ✭✭✭ Gaoth Laidir


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

    goes16_ir_14L_201810092003.jpg?25.5273.6

    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.


  • Registered Users Posts: 8,202 ✭✭✭ Gaoth Laidir


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

    2018AL14_MPSATWND_201810091800_SWHR.GIF

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

    2018AL14_AIRCTCWA_201810091800_SWHR.GIF


  • Registered Users Posts: 21,821 ✭✭✭✭ 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.


  • Registered Users Posts: 8,202 ✭✭✭ 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.

    diag20181009T193141_amsr2_37.png

    diag20181009T193143_amsr2_85.png


  • Registered Users Posts: 21,821 ✭✭✭✭ Kermit.de.frog


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

    Pressure 957 mbs, 120 mph sustained, Gusts 150 mph


  • Registered Users Posts: 21,821 ✭✭✭✭ 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


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  • Registered Users Posts: 8,202 ✭✭✭ 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.


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