Free Republic
Browse · Search
News/Activism
Topics · Post Article

000
WTNT41 KNHC 041449
TCDAT1

Hurricane Irma Discussion Number  21
NWS National Hurricane Center Miami FL       AL112017
1100 AM AST Mon Sep 04 2017

The satellite presentation of Irma has improved markedly over the
past 24 hours, with the eye becoming larger and much more distinct.
A NOAA Hurricane Hunter aircraft has reported peak 700-mb flight
level winds of 117 kt, SFMR winds of 107 kt, and dropsonde data
that support a minimum pressure of around 944 mb. These data
support an initial intensity of 105 kt. The aircraft also reported
concentric eyewalls and a double wind maximum during the last couple
of passes through the center, indicating that an eyewall
replacement cycle has likely begun.

Irma is expected to remain within a very favorable environment for
strengthening during the next several days and additional
intensification appears likely. However, eyewall replacement cycles
are likely to cause some fluctuations in intensity during that time.
The NHC forecast brings the hurricane to category 4 strength within
the next 24 hours, and then maintains Irma as a powerful hurricane
during the next 5 days, assuming that the core of the cyclone does
not move over any of the Greater Antilles.

Irma has been moving west-southwestward or 255/11 kt to the south of
a strong mid-level ridge over the central Atlantic. The hurricane
should turn westward later today or tonight, then west-northwestward
Tuesday as it reaches the southwestern portion of the ridge. As
mentioned in the previous NHC discussion, a large mid-latitude
trough is expected to amplify over the eastern United States during
the next few days. The global models are unanimous in lifting the
trough out to the northeast by late in the week, allowing the
Atlantic ridge to build westward on days 3 through 5. The track
guidance has again shifted westward and southwestward at days 4 and
5, but the models remain in very good agreement through the forecast
period. The updated NHC track forecast has been adjusted
southwestward late in the period, and lies very near the consensus
of the ECMWF, GFS, and HWRF models.

Six hourly upper-air soundings will begin at 1800 UTC today over the
central United States to better sample the upstream mid-latitude
trough. In addition, the NOAA G-IV aircraft will begin sampling the
environment around Irma this afternoon and evening, and these data
will be included in tonight's 0000 UTC model runs.

Users are reminded to not focus on the exact forecast track since
strong winds and heavy rainfall extend well away from the center.
In addition, average NHC track errors are about 175 and 225 statute
miles at days 4 and 5, respectively.

KEY MESSAGES:

1. Irma is expected to affect the northeastern Leeward Islands as a
dangerous major hurricane, accompanied by life-threatening wind,
storm surge, and rainfall impacts, along with rough surf and rip
currents. Hurricane warnings have been issued for portions of the
Leeward Islands. Preparations should be rushed to completion, as
tropical-storm force winds are expected to first arrive in the
hurricane warning area by late Tuesday.

2. Irma could directly affect the British and U.S. Virgin Islands
and Puerto Rico as a dangerous major hurricane later this week.
Hurricane watches have been issued for these areas, and tropical-
storm-force winds could arrive in these areas by early Wednesday.

3. Irma could directly affect Hispaniola, the Turks and Caicos, the
Bahamas, and Cuba as a dangerous major hurricane later this week.
Residents in these areas should monitor the progress of Irma and
listen to advice given by officials.

4. There is an increasing chance of seeing some impacts from Irma in
the Florida Peninsula and the Florida Keys later this week and this
weekend. In addition, rough surf and dangerous marine conditions
will begin to affect the southeastern U.S. coast by later this week.
Otherwise, it is still too early to determine what direct impacts
Irma might have on the continental United States. However, everyone
in hurricane-prone areas should ensure that they have their
hurricane plan in place, as we are now near the peak of the season.
 

FORECAST POSITIONS AND MAX WINDS

INIT 04/1500Z 16.8N 53.3W 105 KT 120 MPH
12H 05/0000Z 16.5N 54.8W 115 KT 130 MPH
24H 05/1200Z 16.7N 57.1W 120 KT 140 MPH
36H 06/0000Z 17.3N 59.6W 120 KT 140 MPH
48H 06/1200Z 18.2N 62.4W 125 KT 145 MPH
72H 07/1200Z 19.9N 68.0W 120 KT 140 MPH
96H 08/1200Z 21.2N 73.3W 115 KT 130 MPH
120H 09/1200Z 22.0N 77.8W 115 KT 130 MPH...NEAR THE COAST OF CUBA

$$
Forecaster Brown

http://www.nhc.noaa.gov/text/refresh/MIATCDAT1+shtml/041449.shtml


1 posted on 09/04/2017 8:03:04 AM PDT by Ray76
[ Post Reply | Private Reply | View Replies ]


To: Ray76

older posts about this storm

http://www.freerepublic.com/focus/news/3582212/posts

This new thread was started since

1) watches/warnings have now been issued for US territory
2) it is becoming increasingly likely that Florida will be hit

These developments deserve attention


2 posted on 09/04/2017 8:08:38 AM PDT by Ray76 (Republicans are a Democrat party front group.)
[ Post Reply | Private Reply | To 1 | View Replies ]

To: Ray76

Florida Plan A: Hay for the horses, beer for the frige, gas for the stuff, already got ammo...


6 posted on 09/04/2017 8:47:19 AM PDT by DanielRedfoot (PoDunk)
[ Post Reply | Private Reply | To 1 | View Replies ]

To: Ray76

A cat 5 going through islands is bad, no place to evacuate. Hope they have some good shelters.


7 posted on 09/04/2017 8:47:34 AM PDT by Rusty0604
[ Post Reply | Private Reply | To 1 | View Replies ]

To: Ray76

8 posted on 09/04/2017 8:48:42 AM PDT by blam
[ Post Reply | Private Reply | To 1 | View Replies ]

To: Ray76
I'm in Delray Beach (between Ft. Lauderdale and Palm Beach), so I'm getting pretty concerned.

I have a new whole-house generator with about 96 hours of fuel (longer if I ration myself). I have a fair amount of bottled water left over from Matthew last year, and will fill containers with more. Already pulled together insurance papers, passports, some cash etc. to put in my large metal ammo box.. along with expensive camera bodies/lenses, medications, etc.

Most of my window/doors are impact, and I already know where the shutters are for the ones that aren't... so if things still look dire toward the end of the week I'll deal with those, patio furniture, etc.

Still not sure of the status of my 2 friends from South Africa, who are currently in Jamaica and scheduled to fly back here (Ft. Lauderdale) on the 8'th and out to Las Vegas on the 9'th. They might get stuck in Jamaica, or if they make it here they might get stuck here.

21 posted on 09/04/2017 10:25:10 AM PDT by Cementjungle
[ Post Reply | Private Reply | To 1 | View Replies ]

To: Ray76

I sure hope it doesn’t end up slamming Texas. They desperately need a breather.


23 posted on 09/04/2017 10:44:48 AM PDT by aquila48
[ Post Reply | Private Reply | To 1 | View Replies ]

To: Ray76
000
WTNT41 KNHC 050237
TCDAT1

Hurricane Irma Discussion Number  23
NWS National Hurricane Center Miami FL       AL112017
1100 PM AST Mon Sep 04 2017

Irma's satellite presentation remains quite impressive with a
well-defined eye and a symmetrical CDO containing very cold cloud
tops. Flight-level and SFMR-observed surface winds from NOAA and
Air Force Hurricane Hunter aircraft indicate that the current
intensity is about 120 kt. Since the hurricane will be moving
through an environment of low vertical wind shear, a moist mid-level
atmosphere, and increasing upper-ocean heat content, additional
intensification is likely. The only expected impediment to
strengthening should be eyewall replacement cycles, which are
difficult to predict. The official intensity forecast is very
close to the latest model consensus, ICON. Although the consensus
of the guidance shows slight weakening in the 96- to 120-hour time
frame, Irma is forecast to remain a powerful hurricane throughout
the 5-day forecast period.

Center fixes from the aircraft indicate a westward motion of about
270/11 kt. Irma should turn toward the west-northwest tomorrow
while it is steered by the flow to the south of a mid-level ridge.
A broad trough is forecast to amplify over the eastern U.S. in
72 hours and then lift northeastward leaving a weakness in the ridge
to north of the hurricane. This should cause a slowing of the
forward speed near the end of the forecast period. The official
track forecast is similar to the previous one and is close to the
model consensus.

Users are reminded to not focus on the exact forecast track,
especially at the longer ranges, since the average NHC track errors
are about 175 and 225 statute miles at days 4 and 5, respectively.

KEY MESSAGES:

1. Irma is expected to affect the northeastern Leeward Islands a
dangerous major hurricane, accompanied by life-threatening wind,
storm surge, and rainfall impacts. Hurricane warnings are in effect
for portions of the Leeward Islands. Preparations should be rushed
to completion, as tropical-storm force winds are expected to first
arrive in the hurricane warning area by late Tuesday.

2. Irma is also expected affect the British and U.S. Virgin
Islands and Puerto Rico as a dangerous major hurricane later this
week. Hurricane warnings have been issued for these areas, and
tropical-storm-force winds could arrive in these areas by early
Wednesday.

3. Irma could directly affect Hispaniola, the Turks and Caicos, the
Bahamas, and Cuba as a dangerous major hurricane later this week.
Residents in these areas should monitor the progress of Irma and
listen to advice given by officials.

4. There is an increasing chance of seeing some impacts from Irma in
the Florida Peninsula and the Florida Keys later this week and this
weekend. Otherwise, it is still too early to determine what direct
impacts Irma might have on the continental United States. However,
everyone in hurricane-prone areas should ensure that they have their
hurricane plan in place.

FORECAST POSITIONS AND MAX WINDS

INIT 05/0300Z 16.7N 55.6W 120 KT 140 MPH
12H 05/1200Z 16.9N 57.4W 125 KT 145 MPH
24H 06/0000Z 17.5N 60.0W 130 KT 150 MPH
36H 06/1200Z 18.3N 62.7W 130 KT 150 MPH
48H 07/0000Z 19.3N 65.5W 125 KT 145 MPH
72H 08/0000Z 21.2N 71.0W 120 KT 140 MPH
96H 09/0000Z 22.5N 76.0W 115 KT 130 MPH
120H 10/0000Z 24.0N 80.0W 115 KT 130 MPH

$$
Forecaster Pasch

http://www.nhc.noaa.gov/text/refresh/MIATCDAT1+shtml/050237.shtml


32 posted on 09/04/2017 7:44:34 PM PDT by Ray76 (Republicans are a Democrat party front group.)
[ Post Reply | Private Reply | To 1 | View Replies ]

Free Republic
Browse · Search
News/Activism
Topics · Post Article


FreeRepublic, LLC, PO BOX 9771, FRESNO, CA 93794
FreeRepublic.com is powered by software copyright 2000-2008 John Robinson