TS Irma: Weakening Over Central Florida

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Nuby33
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DoctorMu wrote:0Z GFS takes Irma closer to the East Coast:

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what about the one in the Caribbean? any hints?
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srainhoutx
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Hurricane Irma is a small Major Hurricane. Hurricane force winds appear to only extend out from the center 10 to 15 miles. The 5 Day track as of this morning suggest a bypass of the Leeward Islands, but interest in that Region and the Bahamas need to monitor Irma Updates form The National Hurricane Center the next day or two. The Ensembles suggest a spread regarding the East Coast of the United States. Interest along that Region should also check in daily for Updates.
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unome
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http://www.nhc.noaa.gov/#Irma
https://twitter.com/NHC_Atlantic/status ... 6412580865

5:00 AM AST Mon Sep 4
Location: 16.9°N 52.3°W
Moving: WSW at 14 mph
Min pressure: 961 mb
Max sustained: 115 mph


Hurricane-force winds extend outward up to 30 miles (45 km) from the center, and tropical-storm-force winds extend outward up to 140 miles (220 km).

interactive track: http://www.nhc.noaa.gov/refresh/graphic ... k#contents
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srainhoutx
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BULLETIN
Hurricane Irma Intermediate Advisory Number 20A
NWS National Hurricane Center Miami FL AL112017
800 AM AST Mon Sep 04 2017

...NOAA HURRICANE HUNTER AIRCRAFT FINDS IRMA A LITTLE STRONGER...


SUMMARY OF 800 AM AST...1200 UTC...INFORMATION
----------------------------------------------
LOCATION...16.8N 52.6W
ABOUT 610 MI...980 KM E OF THE LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...120 MPH...195 KM/H
PRESENT MOVEMENT...WSW OR 255 DEGREES AT 14 MPH...22 KM/H
MINIMUM CENTRAL PRESSURE...947 MB...27.96 INCHES


WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:

None.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Hurricane Watch is in effect for...
* Antigua, Barbuda, Anguilla, Montserrat, St. Kitts, and Nevis
* Saba, St. Eustatius, and Sint Maarten
* Saint Martin and Saint Barthelemy

A Hurricane Watch means that hurricane conditions are possible
within the watch area. A watch is typically issued 48 hours before
the anticipated first occurrence of tropical-storm-force winds,
conditions that make outside preparations difficult or dangerous.

Interests in the remainder of the Leeward Islands, the British and
U.S. Virgin Islands, Puerto Rico, and the Dominican Republic should
monitor the progress of Irma. Additional hurricane and tropical
storm watches and warnings will likely be required for portions of
this area later this morning or this afternoon.

For storm information specific to your area, please monitor products
issued by your national meteorological service.


DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
At 800 AM AST (1200 UTC), the eye of Hurricane Irma was located near
latitude 16.8 North, longitude 52.6 West. Irma is moving toward the
west-southwest near 14 mph (22 km/h). A turn toward the west is
expected later today, followed by a west-northwestward turn late
Tuesday. On the forecast track, the center of Irma will move closer
to the Leeward Islands through Tuesday and then be near the northern
Leeward Islands Tuesday night.

Data from a NOAA Hurricane Hunter aircraft indicate that the
maximum sustained winds have increased to near 120 mph (195 km/h)
with higher gusts. Irma is a category 3 hurricane on the
Saffir-Simpson Hurricane Wind Scale. Additional strengthening is
forecast through Tuesday night.

Hurricane-force winds extend outward up to 30 miles (45 km) from
the center, and tropical-storm-force winds extend outward up to 140
miles (220 km).

The latest minimum central pressure estimated from data received by
the reconnaissance aircraft is 947 mb (27.96 inches).


HAZARDS AFFECTING LAND
----------------------
WIND: Hurricane conditions are possible within the watch area by
Tuesday night, with tropical storm conditions possible by late
Tuesday.

SURF: Swells generated by Irma will begin affecting the northern
Leeward Islands today. These swells are likely to cause life-
threatening surf and rip current conditions. Please consult
products from your local weather office.


NEXT ADVISORY
-------------
Next complete advisory at 1100 AM AST.

$$
Forecaster Brown
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srainhoutx
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Labor Day morning briefing from Jeff regarding Hurricane Irma:

Major hurricane Irma with sustained winds of 120mph

Hurricane Watches are in effect for the Leeward Islands

Interest in the Leeward Islands, Bahamas, and the SE US should closely monitor the progress of this hurricane.

Discussion:
USAF mission into Irma overnight has found that the storm is slightly stronger than forecast with maximum sustained winds of 120mph and a central pressure of 947mb. The well defined eye of Irma has warmed and cleared this morning and is surrounded by a deeply convective central dense overcast suggesting intensification continues. Irma is moving toward the WSW which has in the past been a favored direction for intensification direction in this portion of the Atlantic.

Track:
Major track models are in good agreement over the next 3-5 days taking Irma on a general WNW track near/just north of the Leeward Islands and then on a track toward and through the southern Bahamas by this weekend. After day 5 track guidance begins to diverge as to when Irma may make a turn toward the north into a trough over the NE US. It is questionable if this trough will be strong enough to fully turn Irma northward so there is much uncertainty in the extended range of the forecast as Irma nears FL. Forecast track confidence is high through day 3, but falls significantly after day 3.

Intensity:
There appears to be little to prevent intensification and Irma as continued to become better organized overnight. Irma is a well developed hurricane with a well defined eye embedded within a ring of deep convection. Intensity guidance show Irma becoming a dangerous category 4 hurricane and maintaining that intensity through the next 3-4 days.

While it is too early to tell if Irma will directly impact the FL/US coast, residents over the SE US should closely monitor this hurricane.


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Any thoughts?
No rain, no rainbows.
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srainhoutx
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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

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srainhoutx
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Hurricane Irma Discussion Number 22
NWS National Hurricane Center Miami FL AL112017
500 PM AST Mon Sep 04 2017

Irma remains an impressive hurricane in satellite imagery. The
eye has become a little smaller and cloud filled this afternoon,
perhaps the result of an ongoing eyewall replacement. An Air Force
reserve reconnaissance aircraft reported a double-eyewall structure
and double wind maximums during the first pass through Irma but
noted that the eyewalls had consolidated somewhat during their
second pass through the center. The aircraft measured
flight-level wind of 121 kt in the northeast eyewall and SFMR winds
of 113 kt. Based on these reports, the peak intensity has been
increased to 115 kt, making Irma a category four hurricane.

The hurricane will be moving through an environment of low vertical
wind shear, a moist mid-level atmosphere, and increasing upper-ocean
heat content. These conditions favor intensification and the
intensity guidance continues to call for some additional
strengthening during the next couple of days. However, there are
likely to be eyewall cycles that are difficult to predict, which
could result in some fluctuations in intensity. Barring land
interaction with the islands of the Greater Antilles, Irma is
forecast to remain a powerful hurricane throughout the 5-day
forecast period.

Irma has been moving a little south of due west today, and the
longer-term motion estimate is 265/11 kt. The hurricane will
reach the southwestern portion of a strong mid-level ridge that is
centered over the central Atlantic later today or tonight. This
should result in a westward, then west-northwestward turn over the
next 24 to 36 hours. This motion is expected to bring the hurricane
near or over the northern Leeward Islands on Tuesday night or early
Wednesday. A large mid-latitude trough that is predicted to deepen
over the eastern U.S. during the next few days is forecast to lift
northeastward late in the week, which is expected to cause the
subtropical ridge over the western Atlantic to build westward.
As a result, Irma is predicted to remain on a general
west-northwestward heading on days 3 through 5. The dynamical
model guidance is in excellent agreement through 72 hours, with
some increase in spread late in the period, however the typically
more reliable ECMWF and GFS are in very good agreement through day
5, and the new NHC track forecast lies very close to those models.

Six hourly upper-air soundings began at 1800 UTC today over the
central United States to better sample the upstream mid-latitude
trough. In addition, the NOAA G-IV aircraft is currently sampling
the environment around Irma, 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 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 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. 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 04/2100Z 16.7N 54.4W 115 KT 130 MPH
12H 05/0600Z 16.6N 56.2W 125 KT 145 MPH
24H 05/1800Z 17.0N 58.7W 130 KT 150 MPH
36H 06/0600Z 17.8N 61.3W 130 KT 150 MPH
48H 06/1800Z 18.7N 64.1W 125 KT 145 MPH
72H 07/1800Z 20.4N 69.7W 120 KT 140 MPH
96H 08/1800Z 21.6N 74.8W 115 KT 130 MPH
120H 09/1800Z 23.0N 79.0W 115 KT 130 MPH

$$
Forecaster Brown
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DoctorMu
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Irma is a major league CAT 4 with winds of 145 max sustained.

Image

Florida still under the gun. Fingers crossed the front protects us, as Tuesday's front and drier weather is ≤24 hours away

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The models have been jogging a bit all day. 0Z GFS currently shows a direct hit on the Everglades with Cat 5 level pressures. Hope all in south Florida are getting prepared.

Image

The Canadian model sees a weaker eastern Golf storm. The cone of uncertainly has a spread that could range from running up the east coast just off shore to a GoM storm.


Really concerned about the rapid intensification of Harvey and Irma in the GoM and Atlantic bath water. Hope this is not a sign of things to come.
unome
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whatever she hits, won't be the same when she's done

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