ATL: SAM - Models

[pgoss11]

Anyone else having trouble with Tropical Tidbits site?

Yes, here is the latest 06z GFS from weathernerds.

https://i.imgur.com/eyYKWbZ.gif

Thanks for posting.

[tolakram]

Tropical Tidbits running a little faster now.

GFS


EURO

[NDG]

12z GFS continues to be persistent that Sam will track well NE of the Leeward Islands.

[DioBrando]

Analogs:


Path prediction:


I'd say "Gabrielle 1989" (i.e. the storm that's a little east of the Leewards and made a "C"-shaped path just missing New England and Canada) might be the best fit... so far.

[DioBrando]

also note that sam was trending westwards

[Hurricaneman]

Analogs:
https://web.uwm.edu/hurricane-models/models/al182021_analogs.png

Path prediction:
https://web.uwm.edu/hurricane-models/models/al182021_ens.png

I'd say "Gabrielle 1989" (i.e. the storm that's a little east of the Leewards and made a "C"-shaped path just missing New England and Canada) might be the best fit... so far.
https://cdn.discordapp.com/attachments/800876865430356021/891361622893944902/unknown.png

That’s Edouard 1996, Gabrielle 1989 is farther east

[DioBrando]

Analogs:
https://web.uwm.edu/hurricane-models/models/al182021_analogs.png

Path prediction:
https://web.uwm.edu/hurricane-models/models/al182021_ens.png

I'd say "Gabrielle 1989" (i.e. the storm that's a little east of the Leewards and made a "C"-shaped path just missing New England and Canada) might be the best fit... so far.
https://cdn.discordapp.com/attachments/800876865430356021/891361622893944902/unknown.png

That’s Edouard 1996, Gabrielle 1989 is farther east

Oh, sorry, my bad!

[supercane4867]

12z euro makes a direct hit on Bermuda

[Spacecoast]

Multi model plots from 18z runs

[IcyTundra]

The GFS intialized Sam at 968 mb.

[aspen]

The HMON and HWRF have been showing a second peak in the 940s/930s starting after an EWRC around mid-week.

[aspen]

06z HMON shows a second peak between Thursday afternoon and midday Friday, where Sam gets down to 926mb and peaks at 135 kt at the end of the run. This correlates with an increase in OHC on Thursday. By comparison, the 06z HWRF keeps Sam fluctuating in the 940s to low-mid 950s during the next 5 days.

[LarryWx]

12Z UKMET says look out Bermuda as this run’s center only barely misses it to the east and thus hits it hard with its northern and western side as still a major hurricane:

 

GLOBAL MODEL DATA TIME 1200UTC 26.09.2021

HURRICANE SAM ANALYSED POSITION : 13.9N 50.2W

ATCF IDENTIFIER : AL182021

LEAD CENTRAL MAXIMUM WIND
VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS)
-------------- ---- -------- ------------- -------------
1200UTC 26.09.2021 0 13.9N 50.2W 947 104
0000UTC 27.09.2021 12 14.5N 50.6W 963 88
1200UTC 27.09.2021 24 15.4N 51.5W 970 76
0000UTC 28.09.2021 36 16.3N 52.3W 975 66
1200UTC 28.09.2021 48 17.1N 53.4W 976 67
0000UTC 29.09.2021 60 17.8N 54.4W 978 61
1200UTC 29.09.2021 72 18.6N 55.8W 978 63
0000UTC 30.09.2021 84 19.8N 57.6W 971 72
1200UTC 30.09.2021 96 21.1N 59.7W 966 74
0000UTC 01.10.2021 108 23.3N 61.5W 964 79
1200UTC 01.10.2021 120 25.9N 63.4W 962 79
0000UTC 02.10.2021 132 29.4N 64.5W 956 85
1200UTC 02.10.2021 144 33.7N 63.8W 943 105

Aside: But if I were to have to be stuck on an island in the middle of the ocean in a hurricane though, I’d pick Bermuda first. They handle them quite well for several reasons.

[DioBrando]

12Z UKMET says look out Bermuda as this run’s center only barely misses it to the east and thus hits it hard with its northern and western side as still a major hurricane:

 

GLOBAL MODEL DATA TIME 1200UTC 26.09.2021

HURRICANE SAM ANALYSED POSITION : 13.9N 50.2W

ATCF IDENTIFIER : AL182021

LEAD CENTRAL MAXIMUM WIND
VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS)
-------------- ---- -------- ------------- -------------
1200UTC 26.09.2021 0 13.9N 50.2W 947 104
0000UTC 27.09.2021 12 14.5N 50.6W 963 88
1200UTC 27.09.2021 24 15.4N 51.5W 970 76
0000UTC 28.09.2021 36 16.3N 52.3W 975 66
1200UTC 28.09.2021 48 17.1N 53.4W 976 67
0000UTC 29.09.2021 60 17.8N 54.4W 978 61
1200UTC 29.09.2021 72 18.6N 55.8W 978 63
0000UTC 30.09.2021 84 19.8N 57.6W 971 72
1200UTC 30.09.2021 96 21.1N 59.7W 966 74
0000UTC 01.10.2021 108 23.3N 61.5W 964 79
1200UTC 01.10.2021 120 25.9N 63.4W 962 79
0000UTC 02.10.2021 132 29.4N 64.5W 956 85
1200UTC 02.10.2021 144 33.7N 63.8W 943 105

Aside: But if I were to have to be stuck on an island in the middle of the ocean in a hurricane though, I’d pick Bermuda first. They handle them quite well for several reasons.

They handled Gerardo very well in 2014. Thought that might have ended up as another Fabian tbh.

[Teban54]

For the past 3 runs, GFS is back to showing Sam swinging back west when approaching Newfoundland, possibly as an extratropical cyclone. 12z does this offshore, but 18z makes it traverse Newfoundland east to west and then hit Nova Scotia from the NE, and 00z stalls it just north of Newfoundland for a day.

This has the potential to be bad for Atlantic Canada, IMO.

[kevin]

HMON seems to indicate that Sam hasn't peaked yet. HMON weakened Sam to ~100 kt the last few hours due to the EWRC which seems realistic and now has it bounce back to a cat 4 for the next 5 days at least and even peaks it as a cat 5 on Friday.

[aspen]

The UL wind forecast on the most recent GFS and HWRF runs suggests Sam’s time for intensification will close sometime on Wednesday afternoon, as it crosses 20N. It will lose its perfect outflow pattern and soon start interacting with that trough coming its way. However, Wednesday will be when it moves back over some higher OHC, so it could have one last burst of intensification before leveling off.

[aspen]

06z HMON shows Sam reaching a second peak of 125kt/938mb tomorrow afternoon or evening, and makes landfall in Newfoundland as a powerful newly transitioned non-tropical cyclone.

[aspen]

Yet another Thursday afternoon peak on the 12z HMON, this time stronger at 130kt/935mb. Seeing how good Sam’s UL structure is and how it’s progressing with an EWRC, this might actually verify.

[kevin]

Yet another Thursday afternoon peak on the 12z HMON, this time stronger at 130kt/935mb. Seeing how good Sam’s UL structure is and how it’s progressing with an EWRC, this might actually verify.

There should be recon in Sam at 1800z tomorrow so 2pm EST so hopefully it'll be able to catch Sam's final peak. After that the next recon will be 12 hours later at 2am EST on Friday (0600z).