ATL: MATTHEW - Models

[FLpanhandle91]

[b]What is the suspected strength at that point?

Very strong cat 4/cat 5 and a bit larger circulation than now.

[tolakram]

[chaser1]

What is the suspected strength at that point?

Painfully strong - 929mb. (and thats likely with a stronger gradient further north too)

[Hurricaneman]

the 0zGFS would give winds of 110 to 120mph from Cape Fear to Cape Hatteras

[Alyono]

To see an East Coast strike, the chances will increase if the trough is STRONGER, not WEAKER. A stronger trough will have a sharper, or even a negative tilt, which will bring the storm into the coast. A weak trough will send it northeast

Even without a stronger ridge?

Yes. A negative tilt will have a SSE to NNW steering flow. A strong ridge would only serve to cause that motion to be rapid. I suspect that is what caused Hazel to move so quickly. It had the negative tilt and the strong ridge

[PTrackerLA]

The threat to North Carolina remains very real as evidenced by the 00z GFS. Disconcerting to see the GFS swing back west so close to a NC landfall after shifting east the last two runs. Full resolution has a pressure of 929mb right off Cape Hatteras!

[tolakram]

Merges with a front.

[WHYB630]

162hrs: hit maine, the negative trough provides N-NNE steering

[meriland23]

What is the suspected strength at that point?

Painfully strong - 929mb. (and thats likely with a stronger gradient further north too)

Okay, then how is it the NHC predicts this will dwindle down to below major status by the time it comes up?

[Alyono]

UKMET says...

MET OFFICE TROPICAL CYCLONE GUIDANCE FOR NORTH-EAST PACIFIC AND ATLANTIC

GLOBAL MODEL DATA TIME 0000UTC 03.10.2016

HURRICANE MATTHEW ANALYSED POSITION : 14.4N 74.8W

ATCF IDENTIFIER : AL142016

LEAD CENTRAL MAXIMUM WIND
VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS)
-------------- ---- -------- ------------- -------------
0000UTC 03.10.2016 0 14.4N 74.8W 980 59
1200UTC 03.10.2016 12 15.3N 74.6W 976 59
0000UTC 04.10.2016 24 16.9N 74.3W 975 61
1200UTC 04.10.2016 36 18.9N 74.0W 975 61
0000UTC 05.10.2016 48 20.9N 74.2W 974 64
1200UTC 05.10.2016 60 22.4N 74.8W 975 61
0000UTC 06.10.2016 72 23.9N 75.2W 973 61
1200UTC 06.10.2016 84 25.3N 75.9W 968 67
0000UTC 07.10.2016 96 27.0N 76.4W 959 76
1200UTC 07.10.2016 108 28.8N 77.1W 947 75
0000UTC 08.10.2016 120 30.7N 78.0W 945 77
1200UTC 08.10.2016 132 32.6N 78.0W 946 74
0000UTC 09.10.2016 144 35.1N 76.6W 955 68

[tolakram]

I believe this is the first run with the full set of data from this afternoons upper air flight?

[wxmann_91]

GFS ultimately clips Cape Cod and then brings Matthew ashore in Maine. Reminiscent of some GFS solutions in the past. As Alyono mentioned, having a stronger, more neutral-negatively tilted trof is the key. And the slightly faster storm motion and slower trof allows this to make it just far enough west to impact the CONUS.

[FLpanhandle91]

To see an East Coast strike, the chances will increase if the trough is STRONGER, not WEAKER. A stronger trough will have a sharper, or even a negative tilt, which will bring the storm into the coast. A weak trough will send it northeast

Even without a stronger ridge?

Yes. A negative tilt will have a SSE to NNW steering flow. A strong ridge would only serve to cause that motion to be rapid. I suspect that is what caused Hazel to move so quickly. It had the negative tilt and the strong ridge

Alyono, what would you predict becomes the dominant steering factor for Matthew if the trend for an EC strike held true. The negatively tilted trough or a stronger ridge?

[Alyono]

What is the suspected strength at that point?

Painfully strong - 929mb. (and thats likely with a stronger gradient further north too)

Okay, then how is it the NHC predicts this will dwindle down to below major status by the time it comes up?

LGEM says so. Same reason they have used for all of their forecasts

[jason1912]

CMC is way west of 12z.

[AdamFirst]

The UKMET windshield wipers to the eastern side of the model guidance, after being on the west side at 12z.

Okay then.

[wxmann_91]

What is the suspected strength at that point?

Painfully strong - 929mb. (and thats likely with a stronger gradient further north too)

At such high latitudes the model-projected intensities have little chance of verifying. It will probably be unraveling at that point due to its size, entrainment of dry air from the continent, and increasing shear. Baroclinic support might give it a brief boost near/north of Hatteras but nothing like 929 mb intensities.

The pressure gradient is real though, and both the GFS and Euro would imply significant swells and beach erosion from the strong pressure gradient between Matthew and the surface high to the north.

[Alyono]

Even without a stronger ridge?

Yes. A negative tilt will have a SSE to NNW steering flow. A strong ridge would only serve to cause that motion to be rapid. I suspect that is what caused Hazel to move so quickly. It had the negative tilt and the strong ridge

Alyono, what would you predict becomes the dominant steering factor for Matthew if the trend for an EC strike held true. The negatively tilted trough or a stronger ridge?

if the hit is in SC or southern NC, the ridge. For New England, it is the trough orientation

[PTrackerLA]

00z UKMET hits NC.

00z GFS puts Hatteras in the eyewall and landfalls in Maine. Sheesh.

[WeatherEmperor]

UKMET says...

MET OFFICE TROPICAL CYCLONE GUIDANCE FOR NORTH-EAST PACIFIC AND ATLANTIC

GLOBAL MODEL DATA TIME 0000UTC 03.10.2016

HURRICANE MATTHEW ANALYSED POSITION : 14.4N 74.8W

ATCF IDENTIFIER : AL142016

LEAD CENTRAL MAXIMUM WIND
VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS)
-------------- ---- -------- ------------- -------------
0000UTC 03.10.2016 0 14.4N 74.8W 980 59
1200UTC 03.10.2016 12 15.3N 74.6W 976 59
0000UTC 04.10.2016 24 16.9N 74.3W 975 61
1200UTC 04.10.2016 36 18.9N 74.0W 975 61
0000UTC 05.10.2016 48 20.9N 74.2W 974 64
1200UTC 05.10.2016 60 22.4N 74.8W 975 61
0000UTC 06.10.2016 72 23.9N 75.2W 973 61
1200UTC 06.10.2016 84 25.3N 75.9W 968 67
0000UTC 07.10.2016 96 27.0N 76.4W 959 76
1200UTC 07.10.2016 108 28.8N 77.1W 947 75
0000UTC 08.10.2016 120 30.7N 78.0W 945 77
1200UTC 08.10.2016 132 32.6N 78.0W 946 74
0000UTC 09.10.2016 144 35.1N 76.6W 955 68

Its about darn time this thing is starting to get a grip on reality. Geez!!


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