ATL: IRMA - Post-Tropical - Discussion

[HurricaneBelle]

Wow, Tampa went up in the wind speed probabilities from 45/16/8 to 70/38/25 for 34kt/50kt/64kt wind speeds. That's quite a jump in 6 hours and obviously informed by the 12Z Euro run.

[MetroMike]

Well yes day 4 is in Georgia, my bad

[Aric Dunn]

Well yes day 4 is in Georgia, my bad

even by the time it reaches orlando it will be quite a bit weaker.

[Hurrilurker]

It looks like Turks & Caicos is about to take a direct hit from the right-side eye wall of Irma, at a time when she is likely strengthening. Will be devastating, possibly as bad or worse than Barbuda.

Some weather station links for those islands (Providenciales looks like the most populated part):

Providenciales
https://www.wunderground.com/weather/tc/providenciales

Amergris Cay
https://www.wunderground.com/personal-w ... =ICAICOSI6

Grace Bay
https://www.wunderground.com/personal-w ... =IPROVIDE8

Momentous Centre
https://www.wunderground.com/weathersta ... =ITHEVILL2

[tolakram]

[Aric Dunn]

Currently if you placed IRMA middle of the state. the outer edges of the eyewall would be touching both coasts..

[meriland29]

[tolakram]

000
WTNT41 KNHC 072059
TCDAT1

Hurricane Irma Discussion Number 35
NWS National Hurricane Center Miami FL AL112017
500 PM EDT Thu Sep 07 2017

Hurricane Irma continues to have an impressive satellite
presentation with a very distinct eye. There is not much more to add
about the current intensity except that numerous data from the Air
Force reconnaissance plane indicate that the winds remain at 150
kt.

The environment along the future track of Irma is favorable for the
hurricane to maintain most of its current intensity, although some
fluctuations are likely due to eyewall replacement cycles which are
difficult to predict. There are no obvious reasons why Irma should
not remain a powerful major hurricane for the next 3 days while it
is heading for Florida or its adjacent surroundings. Thereafter, an
increase in the wind shear and the interaction with land should lead
to gradual weakening.

The best estimate of the initial motion is toward the west-northwest
or 285 degrees at 14 kt. Irma is being steered by the flow around
the south side of the subtropical ridge, but in 2 or 3 days the
hurricane is expected to be located on the southwestern edge of the
aforementioned ridge, and a turn to the northwest and north-
northwest should then begin. The forecast track for the first 2 days
was adjusted a little bit to the south given that the ridge to the
north continues to be strong, and the ECMWF and HFIP corrected
consensus (HCCA) models have shifted southward a little bit. These
two models have been performing very well during Irma. This
adjustment also results in a westward shift of the track near
Florida and northward.


KEY MESSAGES:

1. Irma is a potentially catastrophic category 5 hurricane and will
continue to bring life-threatening wind, storm surge, and rainfall
hazards to the northern coast of Hispaniola tonight. These hazards
are already spreading across the Turks and Caicos and will affect
the Bahamas tonight through Saturday. Hurricane conditions will also
spread over portions of the north coast of Cuba, especially over
the adjacent Cuban Keys through Saturday.

2. It has become more likely that Irma will make landfall in
southern Florida as a dangerous major hurricane, and bring
life-threatening storm surge and wind impacts to much of the state.
A Hurricane Watch is in effect for South Florida, the Florida Keys,
Lake Okeechobee, and Florida Bay, and will likely be expanded
northward tonight.

3. A Storm Surge Watch is in effect for portions of South Florida
and the Florida Keys. This means there is the possibility of
life-threatening inundation from rising water moving inland from the
coastline during the next 48 hours in these areas. The Potential
Storm Surge Flooding Map depicts a reasonable worst-case scenario -
the amount of inundation that has a 10 percent chance of being
exceeded. Because the Flooding Map is based on inputs that extend
through 72 hours, it best represents the flooding potential in the
watch area.

4. There is a chance of direct impacts in portions of Georgia,
South Carolina, and North Carolina, but it is too early to specify
the magnitude and location of these impacts.

FORECAST POSITIONS AND MAX WINDS

INIT 07/2100Z 20.9N 71.1W 150 KT 175 MPH
12H 08/0600Z 21.6N 73.1W 145 KT 165 MPH
24H 08/1800Z 22.2N 75.5W 140 KT 160 MPH
36H 09/0600Z 22.7N 77.6W 135 KT 155 MPH
48H 09/1800Z 23.4N 79.3W 135 KT 155 MPH
72H 10/1800Z 26.2N 80.7W 115 KT 130 MPH...INLAND
96H 11/1800Z 31.5N 82.0W 80 KT 90 MPH...INLAND
120H 12/1800Z 36.0N 84.0W 40 KT 45 MPH...INLAND

$$
Forecaster Avila

[lando]

Pbc in the Ne quad of eye wall... damage will be large especially in the far western parts of the county which are much much poorer around the lake. Loss of life potentially high

[cfltrib]

Well yes day 4 is in Georgia, my bad

even by the time it reaches orlando it will be quite a bit weaker.

If the eye goes over the everglades, then is centered on Lake Okeechobee, it won't weaken much until north of there other than possible increased wind shear.

[KBBOCA]

Airport updates:

Fort Lauderdale:
Last flight out of FLL: Friday 7:45 p.m.

 https://twitter.com/FLLFlyer/status/905877296946569217




West Palm:
I can't find any closure info. Here's their website. Virtually nothing helpful. Ugh.
http://www.pbia.org/


Orlando:
I saw a report that Orlando Int'l would close Sat at 5, but that has since been deleted. It looks like there has not been a closure decision yet. Here's latest official update via Twitter:
 https://twitter.com/MCO/status/905784845045026818

[ncweatherwizard]

Obviously, this isn't the most pressing issue in the immediate term, but Irma could end up also being a serious flooding threat in the Appalachians and surrounding foothills, especially in the southern part of the range.

[petit_bois]

Just another shift west... its a trend.

[newtotex]

What kind of weather can Orlando be expecting? I have friends that evacuated from Dade up to Orlando and they don't seem to think it's going to be a big deal inland. I told them they need to be careful

[newtotex]

Well yes day 4 is in Georgia, my bad

even by the time it reaches orlando it will be quite a bit weaker.

If the eye goes over the everglades, then is centered on Lake Okeechobee, it won't weaken much until north of there other than possible increased wind shear.

That's what I have been thinking the models to not take into account at least AFAIK. The waters of the Everglades and Okeechobee are shallow and warm so it will not really aid in weakening Irma

[Hurrilurker]

Hurricane Irma: Solar flares could wreak HAVOC on satellites as storm barrels towards US

THE sun has released two huge solar flares, prompting fears they could affect global communications at a time when satellites are desperately needed.

http://www.express.co.uk/news/science/8 ... satellites

If for some reason the satellites get knocked out, any chance they double up the recon? Or not enough planes & pilots for it?

[Bocadude85]

WPBF West Palm saying if the new forecast track holds Palm Beach County will have sustained winds at 105-125mph with 160mph gusts....I'm speechless

[meriland29]

Hurricane Irma: Solar flares could wreak HAVOC on satellites as storm barrels towards US

THE sun has released two huge solar flares, prompting fears they could affect global communications at a time when satellites are desperately needed.

http://www.express.co.uk/news/science/8 ... satellites

If for some reason the satellites get knocked out, any chance they double up the recon? Or not enough planes & pilots for it?

What the hell is going on?

[Aric Dunn]

even by the time it reaches orlando it will be quite a bit weaker.

If the eye goes over the everglades, then is centered on Lake Okeechobee, it won't weaken much until north of there other than possible increased wind shear.

That's what I have been thinking the models to not take into account at least AFAIK. The waters of the Everglades and Okeechobee are shallow and warm so it will not really aid in weakening Irma

but you cant disregard land friction it will weaken it regardles..

[caneseddy]

So 2:00 pm position on Sunday is around South Florida....high tide at Miami is 12:53 pm...bad news for storm surge most likely in the Biscayne Bay area and the islands within the Bay