Hurricane Dorian

JCX BXC · 31-08-2019 9:22am

Merkin wrote: »

When is this due to reach land?

Read through the thread, looking like late Monday

Gaoth Laidir · 31-08-2019 10:24am

So it looks like Florida will dodge the bullet. With this new track the worst winds would be east or northeast of the centre and well offshore so it's more rain and sea effects that it would have to deal with. By landfall in SC it would be in a weakened state. But poor Bahamas...

Hurricane Dorian Discussion Number 28
NWS National Hurricane Center Miami FL
AL052019 500 AM EDT Sat Aug 31 2019

Dorian continues to look impressive in satellite imagery this morning, with a fairly symmetric area of cold cloud tops surrounding a 10-15 n mi wide eye. There have been no new aircraft data from the storm since the last advisory. However, the satellite appearance has changed little since the aircraft were last in the storm, and the various subjective and objective satellite intensity estimates have changed little over the past several hours. Based on this, the initial intensity remains 120 kt.

The initial motion is now 290/10. A low- to mid-level subtropical ridge to the north of the hurricane should steer it west- northwestward to westward for the next 48 h or so, with the forward speed becoming very slow as the center passes near or over the Abacos and Grand Bahama. The track guidance for this part of the track is tightly clustered, and the new forecast track is near the ECMWF, UKMET, and HCCA corrected consensus models. The track forecast becomes much more problematic after 48 h. The global models the NHC normally uses, along with the regional HWRF and HMON models, have made another shift to the east to the point where none of them forecast Dorian to make landfall in Florida. However, the UKMET ensemble mean still brings the hurricane over the Florida peninsula, as do several GFS and ECMWF ensemble members. The new track forecast for 72-120 h will be moved eastward to stay east of the coast of Florida, and it lies between the old forecast and the various consensus models. Additional adjustments to the forecast track may be necessary later today if current model trends continue. It should be noted that the new forecast track does not preclude Dorian making landfall on the Florida coast, as large portions of the coast remain in the track cone of uncertainty. Also, significant impacts could occur even if the center stays offshore.

Dorian should remain in a generally favorable environment for the next 3-4 days, and the intensity guidance indicates it will remain a powerful hurricane during this time. The new intensity forecast calls for a little more strengthening today, then it shows a slow weakening that follows the trend of the intensity guidance. During this time, the biggest intensity changes may come from hard-to- forecast eyewall replacement cycles. Late in the forecast period, increased vertical shear and proximity to land is expected to cause some weakening.

Meteorite58 · 31-08-2019 10:54am

Certainly looks like it is on the route up along the Eastern Seaboard. Added interest for Ireland for the latter stages of it's life span to see what the remnants have in store for us if any if they reach these latitudes in about 10 to 12 days. One thing for sure is that it will play havoc with the models with probable big swings from run to run , very much a time to watch for trends over the coming days. Models in fair agreement of its route as far as Newfoundland anyway at this stage. Could easily just head up towards Greenland / Iceland, jet will be important and if it merges with other areas of LP etc etc

sparrowcar · 31-08-2019 11:14am

Any idea what time landfall on the Bahamas will be and any decent webcam or live streams to watch?

Edit: Just seen cherryghosts post on first page.

pad199207 · 31-08-2019 11:43am

A Cat 5 or strong Cat 4 up along the coast of Florida would still cause huge damage even if it doesn’t make landfall.

Latest models still startling.

orkyorky · 31-08-2019 12:50pm

Heading straight for ireland coming fast across the atlantic, forget about america

pad199207 · 31-08-2019 2:15pm

Sustained winds are at 145mph now.

sdanseo · 31-08-2019 3:23pm

Another one potentially spinning up off Africa also.

pad199207 · 31-08-2019 3:51pm

Unconfirmed yet by NOAA that latest recorded surface winds are near 160mph!

Confirmed as 150mph now so still just under Cat 5.
West side of the storm doesn’t look as organized perhaps due to some mid level shear. Still obviously not having any effect on the storms intensification

Someone’s prayers were answered. What a dodge.

Gaoth Laidir · 31-08-2019 4:05pm

pad199207 wrote: »

Unconfirmed yet by NOAA that latest recorded surface winds are near 160mph!

Confirmed as 150mph now so still just under Cat 5.
West side of the storm doesn’t look as organized perhaps due to some mid level shear. Still obviously not having any effect on the storms intensification

That was an isolated 138-kt SFMR reading, followed by one of 127 kts.

142730 2603N 07319W 7477 02145 9555 +165 +161 096112 131 138 004 00

It's good to see that track now.moving further offshore and even more away from the northern Bahamas. This could turn into a fishstorm after all that!

Gaoth Laidir · 31-08-2019 4:16pm

Wind field based on aircraft recon data. Max 132 kts just 8 NM to the ENE of the centre. Strongest winds still in a very small area of the eyewall, with 64 kts winds extending only 20-25 NM out.

pad199207 · 31-08-2019 4:27pm

Air Force recording wind of 144 knots in the latest

Gaoth Laidir · 31-08-2019 4:49pm

pad199207 wrote: »

Air Force recording wind of 144 knots in the latest

Really? In Mission 23? It's not showing it in the data. 121 kts is the highest so far.

pad199207 · 31-08-2019 4:59pm

Gaoth Laidir wrote: »

Really? In Mission 23? It's not showing it in the data. 121 kts is the highest so far.

Yeah well to be fair this was mentioned on the CNN Forecast little while ago so I’m sure how accurate it is.
I presume it’s fairly on the ball.

Oneiric 3 · 31-08-2019 5:14pm

pad199207 wrote: »

Yeah well to be fair this was mentioned on the CNN Forecast.

'Nuff said.

pad199207 · 31-08-2019 5:37pm

Gaoth Laidir wrote: »

Really? In Mission 23? It's not showing it in the data. 121 kts is the highest so far.

Recon going back in now so we see what they get.

Meteorite58 · 31-08-2019 5:52pm

pad199207 wrote: »

Yeah well to be fair this was mentioned on the CNN Forecast little while ago so I’m sure how accurate it is.
I presume it’s fairly on the ball.

NOAA reporting near 150mph also.

https://twitter.com/NOAASatellites/status/1167788039873146880?s=20

Dorian tracking slowly right over the Bahamas

ECM takes it very close to the coast of Florida , stall and turn ? Nervy times .

Mean wind speeds

Gaoth Laidir · 31-08-2019 7:00pm

Aircraft recon does show a 140-knot (160 mph) surface wind measured at 16.36 Z, well after that CNN report of 144 kt (166 mph). I think they may have been confusing knots with statute mph. The latest NHC update (18Z) says max 150 mph.

The latest forecast track has it now way out to sea and looking unlikely to ever make landfall at all after the Bahamas.

al052019.19083106.gif

Kermit.de.frog · 31-08-2019 7:16pm

They may dodge a bullet alright.

Meteorite58 · 31-08-2019 7:44pm

Quotes

NHC Director: "The track of Dorian is a game of inches."

Small wobbles one way or another can make a world of difference.

Levi Cowan : ' Weak steering currents & stalling storms should never be trusted.

With 72 hours before Dorian turns north, even a 1 mph error in the storm's speed until then could result in a 72 mile error in how far west Dorian gets.

Stay vigilant. More changes could occur. It's a tough one.'

Ryan Maue 'The eye of Hurricane #Dorian will spend at least 36-hours meandering around Abaco & Grand Bahama Islands ... current forecast track is a disaster: feet of Rain, storm surge, and Cat 4 sustained winds.'

Kermit.de.frog · 31-08-2019 7:49pm

Knife edge stuff - miles the difference between disaster and no disaster

cherryghost · 31-08-2019 7:51pm

The webcams I posted, most of them will come alive tonight into tomorrow morning, you may catch daylight arrival of Dorian around 1/2am in some of them. Dorian has been moving faster across the water but set to slow rapidly upon reaching Bahama islands.

Meteorite58 · 31-08-2019 8:08pm

Dorian looks like it will be a Cat 4 or Cat 5 Hurricane with its eyewall likely to go near or directly over the Abaco Islands as it continues to move over increasing warm waters along with other parameters sustaining its strengthening.

Tropical Tidbits

https://twitter.com/NWSBayArea/status/1167868513551183877?s=20

Kermit.de.frog · 31-08-2019 8:45pm

ECM ensemble in little doubt this will be taking a sharp right turn possibly even before it clears through the Bahamas.

EDUpffHUcAIr4gY?format=jpg&name=900x900

Oneiric 3 · 31-08-2019 8:51pm

ECMWF 12r looking increasingly concerning for the northern Bahama islands, not only in terms of wind potential, but for rainfall also as this model once again stalls the eye just slightly south of Great Bahama island over a protracted period from late Sun through to early Tues at least.

Kermit.de.frog · 31-08-2019 9:12pm

There is still uncertainty of course. GFS still wants to keep the track nearer the coast and ICON takes the eye right up through Florida.

This will be a nowcast. Biggest question is when will it make the turn north?

Gaoth Laidir · 31-08-2019 10:18pm

At the moment the precipitation zone is fairly small and concentrated, with a distinct lack of spiral bands (as shown below). Given the current forecast track, both wind and rain effects in eastern Florida would be fairly limited (gale force winds). We'll probably see this change soon if there's an ERC, but we'd need to see a large change in structure for it to be of major concern.

Hopefully too the bulk of the Bahamas islands will avoid the worst of it if it continues as forecast. Still, where gets it will certainly get it.

20190831.2005.f15.x.pct.05LDORIAN.130kts-945mb-261N-740W.077pc.jpg

20190831.2005.f15.x.pct.05LDORIAN.130kts-945mb-261N-740W.077pc.jpg

Kermit.de.frog · 31-08-2019 10:57pm

18z GFS has it just off Florida coast by Tuesday.

Potentially significant shift back west in terms of impact...particularly in coastal areas.

https://twitter.com/WeatherOwen/status/1167918062902755332

Kermit.de.frog · 31-08-2019 11:30pm

Mission 26 underway

Gaoth Laidir · 01-09-2019 12:02am

One saving grace is the large area of dry low and mid-level airmass (orange/brown) around the north and west of the storm, which is probably why the western side is a bit eroded on satellite imagery. It should prevent strengthening to Cat 5 over the next 24 hours before it gets to the Bahamas, after which upwelling and whatever terrain there is there should help. The LGEM has the storm motion slowing down from its current 8 knots to 3 knots for about 12 hours, before speeding up again. Not a huge decrease in speed over what it's already at.

Mid-level water vapour (animate here)

Low-level

Kermit.de.frog · 01-09-2019 12:16am

2nd recon mission in the storm simultaneously now with a 3rd collecting data on the steering environment in the storm's outer bands. Important data collection now for midnight models (edit - correction - 6z runs!).

Mission 26 so far showing no change from earlier in the day. SLP 941, Max SL wind gust on first pass just under 130 kts or 150 mph.

Second pass will come through northeast eye wall where winds should be even stronger.

Mission 25

Kermit.de.frog · 01-09-2019 12:37am

Mission 25 just recorded a surface level wind speed of 164.6 mph (143 kts) in the northwest eye wall.

Dorian will be a major CAT 5 hurricane in the next update from the NHC. Although seems a bit of a strange correlation given the flight level wind speed data of 145 kts! Should be a lot more distance than that between those figures. Seems suspect, we'll see if the surface level reading holds up in coming passes.

Kermit.de.frog · 01-09-2019 1:11am

Mission 26 just recorded 150 kts surface level wind in northern eye wall.

This supports mission 25 readings and is even higher.

CAT 5 at next NHC advisory.

Gaoth Laidir · 01-09-2019 1:15am

Kermit.de.frog wrote: »

Mission 26 just recorded 150 kts surface level wind in northern eye wall.

This backs mission 25 readings and is even higher.

CAT 5 at next NHC advisory.

That value was 149 knots and has been flagged suspect. The NHC has just updated but has stuck with its earlier 150 mph. We'll see what the next datapoints out say.

sdanseo · 01-09-2019 1:15am

Still Cat 4 in the 8pm EDT (15 mins ago)

Gaoth Laidir · 01-09-2019 1:23am

Gaoth Laidir wrote: »

That value was 149 knots and has been flagged suspect. The NHC has just updated but has stuck with its earlier 150 mph. We'll see what the next datapoints out say.

There was a 148 knots 30 seconds before that, and this has not been flagged, so it could well be Cat 5 now.

000230 2630N 07443W 7526 02368 9887 +135 +135 085105 109 083 018 00
000300 2628N 07443W 7526 02337 9845 +144 +137 086114 117 091 028 00
000330 2626N 07443W 7507 02322 9803 +142 //// 085117 120 098 033 01
000400 2624N 07443W 7510 02272 9750 +144 //// 084125 130 113 032 01
000430 2622N 07443W 7507 02205 9673 +142 //// 082139 142 132 070 01
000500 2621N 07443W 7471 02139 9563 +147 //// 082127 136 148 056 01
000530 2619N 07443W 7515 02027 9462 +181 +168 081080 099 149 045 03
000600 2617N 07443W 7513 01996 9426 +184 +171 080044 050 057 002 00
000630 2615N 07443W 7531 01957 9407 +186 +173 082024 029 037 000 03
000700 2613N 07442W 7530 01957 9405 +183 +173 057008 012 028 000 00
000730 2610N 07442W 7530 01959 9410 +183 +169 272009 015 028 000 00
000800 2608N 07442W 7524 01984 9425 +183 +171 263027 035 045 000 00
000830 2606N 07442W 7519 02010 9449 +182 +165 261057 076 072 007 00
000900 2605N 07442W 7545 02042 9508 +186 +168 261105 117 121 032 03
000930 2603N 07442W 7550 02127 9624 +160 //// 263119 122 118 030 05
001000 2601N 07442W 7564 02185 9714 +154 //// 265110 113 107 012 01
001030 2600N 07442W 7524 02290 9779 +147 //// 268099 101 099 005 01
001100 2558N 07442W 7526 02328 9827 +147 //// 268087 089 088 012 01

Kermit.de.frog · 01-09-2019 1:27am

Gaoth Laidir wrote: »

That value was 149 knots and has been flagged suspect. The NHC has just updated but has stuck with its earlier 150 mph. We'll see what the next datapoints out say.

I think it's cast iron that the NHC will either issue intermediate advisory or upgrade to CAT 5 at next scheduled advisory.

The top data point is marked suspect but the one immediately prior is considered valid and that's 148 kts. Mission 25 was also well in CAT 5 territory (143 kts) and that was in the northwest eye wall.

(edit just seen your updated post)

Gaoth Laidir · 01-09-2019 1:57am

26 has just passed back through the eye from the northeast but only found max 133 knots in the NE eyewall. As the storm is moving westwards it figures that the strongest winds will be in the northern eyewall, which has been the case.

Jpmarn · 01-09-2019 2:00am

The latest gfs run on netweather.tv has the remnants of this hurricane coming our direction by Tuesday the 10th.

Kermit.de.frog · 01-09-2019 2:05am

Gaoth Laidir wrote: »

26 has just passed back through the eye from the northeast but only found max 133 knots in the NE eyewall. As the storm is moving westwards it figures that the strongest winds will be in the northern eyewall, which has been the case.

hmmm that data looks a bit dodgy though just at the crucial time. 26 is making it's next pass. Be interesting to see the reading from the northwestern eye wall.

sdanseo · 01-09-2019 2:34am

Jpmarn wrote: »

The latest gfs run on netweather.tv has the remnants of this hurricane coming our direction by Tuesday the 10th.

+312hrs though, might as well hang a fish on your washing line as a method of forecasting.

gfs-14-312.png?18

Kermit.de.frog · 01-09-2019 2:34am

Yup CAT 5....Mission 26 just recorded 153 kts (176 mph) surface level wind speed in the north west eye wall.

Kermit.de.frog · 01-09-2019 2:49am

They can add 176 mph now.

Kermit.de.frog · 01-09-2019 3:58am

Latest NHC update maintains Dorian at a CAT 4 hurricane. Surprised at that. The data indicates it's well in to CAT 5 territory. They must be sceptical about the flight level winds.

CAT 5

Gaoth Laidir · 01-09-2019 6:31am

Kermit.de.frog wrote: »

Latest NHC update maintains Dorian at a CAT 4 hurricane. Surprised at that. The data indicates it's well in to CAT 5 territory. They must be sceptical about the flight level winds.

CAT 5

From their latest Discussion:

Data from both Air Force and NOAA Hurricane Hunter aircraft indicate that Dorian remains a very powerful hurricane, and the satellite presentation is still quite impressive with a very stable, well-defined eye. There has been no evidence of concentric eyewalls in aircraft or microwave data, which is somewhat surprising given that the intensity has been at category 4 strength for 24 hours. Both aircraft measured peak flight-level winds that support an initial intensity of 130 kt. There have been some higher surface wind estimates from the SFMR, but these data are questionable based on our experience of very high SFMR-measured wind speeds in recent strong hurricanes that didn't match standard flight-level wind reductions.

Very strange indeed, as the SFMR method has been shown to be most accurate up at CAT 5 level. Still, they're the experts.

Comhrá · 01-09-2019 9:03am

Interesting update from https://www.tropicaltidbits.com/

Oneiric 3 · 01-09-2019 9:12am

NHC's latest analysis:

OneEightSeven · 01-09-2019 9:35am

Gaoth Laidir · 01-09-2019 10:35am

Some private weather stations on Abaco are now starting to see pressure dropping and winds increasing, gusting to near 50 mph. Updated every few seconds here

https://www.wunderground.com/dashboard/pws/IABACOEL1

Zoom out on the map to see the other nearby stations

Oneiric 3 · 01-09-2019 11:06am

Apart from one or two outliers, pretty much a cross model consensus now (06z runs) regarding general direction of travel. I wouldn't dismiss any outliers totally though, as the current forecast path was itself considered to be the least likely option only a few days ago.

Hurricane Dorian

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