ATL: MATTHEW - Post-Tropical - Discussion

[Chris_in_Tampa]

NE Quadrant:

SFMR Peak (10s Avg.) Sfc. Wind....

11:15:00Z: 86 knots (99.0 mph)
11:15:30Z: 97 knots (111.6 mph)
11:16:00Z: 98 knots (112.8 mph)
11:16:30Z: 106 knots* (122.0 mph*) ... Suspect
11:17:00Z: Missing ... Where 121 kt 30s avg, 123 kt 10s avg at flight level occurred
11:17:30Z: Missing
11:18:00Z: 128 knots* (147.3 mph*) ... Suspect
11:18:30Z: 46 knots* (52.9 mph*) ... Suspect
11:19:00Z: 34 knots (39.1 mph)
11:19:30Z: 27 knots (31.1 mph)
11:20:00Z: 23 knots (26.5 mph) ... 938.2 mb (27.71 inHg) Extrapolated Sfc. Pressure

Highest Flight Level Wind (30 sec. Avg.): 121 knots (139.2 mph)
Highest Peak (10 sec. Avg.) Flight Level Wind: 123 knots (141.5 mph)

[GCANE]

Looking at 200mb GFS just as Matthew gets in the Gulf Stream:

It appears there will be two ULLs that will enhance an equatorward outflow channel.
One in the mid Carib and the other over the Yucatan.

Poleward outflow appears to be inhibited by the updraft of Nicole.

Also, no UL PV anomolies to distrupt the vortex column; it should be well aligned vertically.

[NotoSans]

Latest dropsonde reports 941 mb with 9 kt surface winds. That would support a central pressure of 940 mb and a 4 mb drop within an hour.

[jdray]

Please remember that this is going to affect inland areas as well, prepare and be safe.
Here's the local Hurricane Statement from NWS JAX for my area (Clay County).
It's a strange sight to see the local NWS office give a statement like this.

Hurricane Warning
MATTHEW LOCAL WATCH/WARNING STATEMENT/ADVISORY NUMBER 33
NATIONAL WEATHER SERVICE JACKSONVILLE FL AL142016
523 AM EDT THU OCT 6 2016

FLZ032-061800-
/O.CON.KJAX.HU.W.1014.000000T0000Z-000000T0000Z/
CLAY-
523 AM EDT THU OCT 6 2016

...HURRICANE WARNING REMAINS IN EFFECT...

* LOCATIONS AFFECTED
- LAKESIDE
- MIDDLEBURG
- ORANGE PARK

* WIND
- LATEST LOCAL FORECAST: EQUIVALENT TROPICAL STORM FORCE WIND
- PEAK WIND FORECAST: 45-55 MPH WITH GUSTS TO 75 MPH
- WINDOW FOR TROPICAL STORM FORCE WINDS: FRIDAY MORNING UNTIL
SATURDAY AFTERNOON

- CURRENT THREAT TO LIFE AND PROPERTY: HIGH
- THE WIND THREAT HAS REMAINED NEARLY STEADY FROM THE
PREVIOUS ASSESSMENT.
- EMERGENCY PLANS SHOULD INCLUDE A REASONABLE THREAT FOR
HURRICANE FORCE WIND OF 74 TO 110 MPH OF EQUIVALENT
CATEGORY 1 TO 2 INTENSITY.
- TO BE SAFE, AGGRESSIVELY PREPARE FOR THE POTENTIAL OF
EXTENSIVE WIND IMPACTS. REMAINING EFFORTS TO SECURE
PROPERTIES SHOULD NOW BE BROUGHT TO COMPLETION.
- DANGEROUS AND LIFE-THREATENING WIND IS POSSIBLE. FAILURE TO
ADEQUATELY SHELTER MAY RESULT IN SERIOUS INJURY OR LOSS OF
LIFE. MOVE TO SAFE SHELTER BEFORE THE WIND BECOMES
HAZARDOUS.

- POTENTIAL IMPACTS: EXTENSIVE
- CONSIDERABLE ROOF DAMAGE TO STURDY BUILDINGS, WITH SOME
HAVING WINDOW, DOOR, AND GARAGE DOOR FAILURES LEADING TO
STRUCTURAL DAMAGE. MOBILE HOMES SEVERELY DAMAGED, WITH SOME
DESTROYED. DAMAGE ACCENTUATED BY AIRBORNE PROJECTILES.
LOCATIONS MAY BE UNINHABITABLE FOR WEEKS.
- MANY LARGE TREES SNAPPED OR UPROOTED ALONG WITH FENCES AND
ROADWAY SIGNS BLOWN OVER.
- SOME ROADS IMPASSABLE FROM LARGE DEBRIS, AND MORE WITHIN
URBAN OR HEAVILY WOODED PLACES. SEVERAL BRIDGES, CAUSEWAYS,
AND ACCESS ROUTES IMPASSABLE.
- LARGE AREAS WITH POWER AND COMMUNICATIONS OUTAGES.

* FLOODING RAIN
- LATEST LOCAL FORECAST: FLOOD WATCH IS IN EFFECT
- PEAK RAINFALL AMOUNTS: ADDITIONAL 4-8 INCHES, WITH LOCALLY
HIGHER AMOUNTS

- CURRENT THREAT TO LIFE AND PROPERTY: MODERATE
- THE FLOODING RAIN THREAT HAS REMAINED NEARLY STEADY FROM
THE PREVIOUS ASSESSMENT.
- EMERGENCY PLANS SHOULD INCLUDE A REASONABLE THREAT FOR
MODERATE FLOODING WHERE PEAK RAINFALL TOTALS NOTABLY EXCEED
AMOUNTS CONDUCIVE FOR FLASH FLOODING AND RAPID INUNDATION.
RESCUES AND EMERGENCY EVACUATIONS ARE POSSIBLE.
- TO BE SAFE, EARNESTLY PREPARE FOR THE POTENTIAL OF
SIGNIFICANT FLOODING RAIN IMPACTS.
- DANGEROUS FLOODING IS POSSIBLE. FAILURE TO TAKE ACTION MAY
RESULT IN SERIOUS INJURY OR LOSS OF LIFE. IF FLOOD RELATED
WATCHES AND WARNINGS ARE ISSUED, HEED RECOMMENDED ACTIONS.

- POTENTIAL IMPACTS: SIGNIFICANT
- MODERATE RAINFALL FLOODING MAY PROMPT SEVERAL EVACUATIONS
AND RESCUES.
- RIVERS AND TRIBUTARIES MAY QUICKLY BECOME SWOLLEN WITH
SWIFTER CURRENTS AND OVERSPILL THEIR BANKS IN A FEW PLACES,
ESPECIALLY IN USUALLY VULNERABLE SPOTS. SMALL STREAMS,
CREEKS, CANALS, AND DITCHES OVERFLOW.
- FLOOD WATERS CAN ENTER SOME STRUCTURES OR WEAKEN
FOUNDATIONS. SEVERAL PLACES MAY EXPERIENCE EXPANDED AREAS
OF RAPID INUNDATION AT UNDERPASSES, LOW-LYING SPOTS, AND
POOR DRAINAGE AREAS. SOME STREETS AND PARKING LOTS TAKE ON
MOVING WATER AS STORM DRAINS AND RETENTION PONDS OVERFLOW.
DRIVING CONDITIONS BECOME HAZARDOUS. SOME ROAD AND BRIDGE
CLOSURES.

* TORNADO
- LATEST LOCAL FORECAST:
- SITUATION IS SOMEWHAT FAVORABLE FOR TORNADOES

- CURRENT THREAT TO LIFE AND PROPERTY: ELEVATED
- THE TORNADO THREAT HAS REMAINED NEARLY STEADY FROM THE
PREVIOUS ASSESSMENT.
- WHEN IMPLEMENTING EMERGENCY PLANS, INCLUDE A REASONABLE
THREAT FOR ISOLATED TORNADOES.
- TO BE SAFE, PREPARE FOR THE POTENTIAL OF LIMITED TORNADO
IMPACTS.
- LISTEN FOR TORNADO WATCHES AND WARNINGS. BE READY TO
SHELTER QUICKLY IF A TORNADO APPROACHES.

- POTENTIAL IMPACTS: LIMITED
- THE OCCURRENCE OF ISOLATED TORNADOES CAN HINDER THE
EXECUTION OF EMERGENCY PLANS DURING TROPICAL EVENTS.
- A FEW PLACES MAY EXPERIENCE TORNADO DAMAGE, ALONG WITH
POWER AND COMMUNICATIONS DISRUPTIONS.
- LOCATIONS COULD REALIZE ROOFS PEELED OFF BUILDINGS,
CHIMNEYS TOPPLED, MOBILE HOMES PUSHED OFF FOUNDATIONS OR
OVERTURNED, LARGE TREE TOPS AND BRANCHES SNAPPED OFF,
SHALLOW-ROOTED TREES KNOCKED OVER, MOVING VEHICLES BLOWN
OFF ROADS, AND SMALL BOATS PULLED FROM MOORINGS.

* FOR MORE INFORMATION:
- HTTP://WWW.WEATHER.GOV/JAX/

$$

[KBBOCA]

Apologies if this has already been posted, but here is the NWS-JAX forecast briefing powerpoint. Lots of important info for you folks in NE FL.

http://www.weather.gov/media/jax/briefi ... iefing.pdf

[windnrain]

First vis of the day.



Funny enough it doesn't look nearly as good on sat as it did yesterday, and yet it is strengthening fast right now.

[Hypercane_Kyle]

Yep, that's my concern. If the NHC track holds we'll be in the western core of a 140mph hurricane, which would likely give me high end Cat 1/ low end Cat 2 conditions similar to what we got with Jeanne and Wilma. A track little further west and we catch the N/NE part of the core and potentially a whole other ballgame. Going to be close

Anyone know how the recent ridge sampling compares to the models?
HWRF tracked east a little for 06Z.

Time to shift from models to real time on Radar now. Perhaps look at the HRRR hourly updated track model.

Probably should avoid using mesoscale models like the HRRR, NAM, and the WRF for TC guidance*. Notoriously bad for that.

[SouthDadeFish]

An argument could be made that Matthew is now a category-4 hurricane. There is still time for the system to strengthen further before it approaches FL. Even if no further strengthening occurs, this is a very dangerous hurricane.

[FLpanhandle91]

The satellite presentation is night and day different compared to 7 or 8 hours ago. Matthew is ventilating well and outflow is enormous and healthy as opposed to non-existent earlier. The circulation has become tighter as a result.

[FLpanhandle91]

An argument could be made that Matthew is now a category-4 hurricane. There is still time for the system to strengthen further before it approaches FL. Even if no further strengthening occurs, this is a very dangerous hurricane.

Do you think this intensification as of late is evidenced by improved outflow on satellite?

[hurricanefloyd5]

8:00 AM EDT Thu Oct 6
Location: 24.6°N 77.5°W
Moving: NW at 12 mph
Min pressure: 940 mb
Max sustained: 125 mph

[northjaxpro]

Apologies if this has already been posted, but here is the NWS-JAX forecast briefing powerpoint. Lots of important info for you folks in NE FL.

http://www.weather.gov/media/jax/briefi ... iefing.pdf

Yeah I know a couple of the NWS Jax mets and they have done a very good job with their web briefings with Matthew.
They have a lot on their plate like many of us right now.

[jhpigott]

What's the wind field like on the western side of the storm?

[SouthDadeFish]

An argument could be made that Matthew is now a category-4 hurricane. There is still time for the system to strengthen further before it approaches FL. Even if no further strengthening occurs, this is a very dangerous hurricane.

Do you think this intensification as of late is evidenced by improved outflow on satellite?

Well, improved outflow can't hurt it! Not sure if the convection is driving the outflow or vice versa. On its current path, it seems like the center will pass directly over northern Andros Island.

[Digital-TC-Chaser]

Think there is a reasonable chance of a super cell tornado any time now over southern florida coming off those outta bands.

[GCANE]

The best performing model for Matthew has been ECMO with an error of 25 miles.
This makes the likely landfall at Jupiter.
However, Matthew has a propensity to deflect toward land on its approach.
So, IMHO at this point, likely landfall would be around West Palm Beach.

[tolakram]

visible loop, as the sun comes up

http://weather.msfc.nasa.gov/cgi-bin/get-goes?satellite=GOES-E%20CONUS&lat=26&lon=-78&info=vis&zoom=1&width=1000&height=800&quality=90&type=Animation&palette=ir1.pal&numframes=10&mapcolor=yellow

[GCANE]

There is in fact very strong helicity ahead of Matthew.
Likely to push into the SE portion of the state later this afternoon.
Tornadoes are likely.

[SouthDadeFish]

An argument could be made that Matthew is now a category-4 hurricane. There is still time for the system to strengthen further before it approaches FL. Even if no further strengthening occurs, this is a very dangerous hurricane.

Do you think this intensification as of late is evidenced by improved outflow on satellite?

Well, improved outflow can't hurt it! Not sure if the convection is driving the outflow or vice versa. On its current path, it seems like the center will pass directly over northern Andros Island.

Actually it may even wobble around Andros to the north. Will be a close call. This puts Nassau closer to the strongest winds.

[MGC]

Just read the local hurricane statement from Melbourne. It is blunt and to the point. "Locations may be uninhabitable for weeks or months" I have not read this dire of a local hurricane statement since Katrina.....and we all know what happened there. Get out now if you can.