Posted on 09/04/2017 6:06:13 AM PDT by John W
That curve to the north – and eventually out into the Atlantic – that everyone in South Florida was hoping to see Hurricane Irma take isn’t happening as quickly as earlier models had predicted. The National Hurricane Center’s 8 a.m. update Monday drives the storm’s path in a flatter, westbound path that puts it closer Cuba’s shores by early Saturday morning.
(Excerpt) Read more at weatherplus.blog.palmbeachpost.com ...
What direction is the high pressure system in the Western Atlantic moving? Also, is there any high pressure system moving down into the southeast United States? I remember about 1999 when the YUUUUUUGE Hurricane Floyd was heading directly towards Ft. Lauderdale suddenly shifted directions at the last moment due to a high pressure system moving in and veered sharply north, thus avoiding a hit here. All we got were some wind gusts of about 50 mph but nothing worse than that.
What direction is that high pressure system in the Atlantic moving?
If look at weather maps see there are 2 high pressure system
One out over Atlantic, second over Midwest
If remain in position IRMA has path right for east coast
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
Not sure. Don’t have time now to check. Probably is basically ‘parked’ there for a while.
So if the Midwest high pressure system moves south, it could keep Irma off the East Coast. That happened in 1999 when a high pressure system moved into Florida to keep Hurricane Floyd from hitting this state.
The Jet Stream and the Ocean always change. So right now it looks bad, but it could change.
My understanding is the Gulf and the ocean East of Florida is like bathwater. So we are probably looking at a Cat 5 Hurricane.
If Irma hugs Cuba’s north coast, the mountains there should weaken it.
Yeah, I was at the beach yesterday and the water was very warm. So warm that I didn't even have the usual initial hesitation to jump in all the way since there was no sense of coldness at all.
That's the key to the fine-grained track, but that will also determine the strength of the downstream high over the Atlantic. They sample the storm for the near-term intensification and direction, but the broader weather pattern is the key to the forecast a week away.
And that said, the pattern a week from now is a crap shoot, like predicting an east coast snowstorm. Sometimes they get it right early but mostly they don't.
This is a major change in the forecast—very bad...
Glad I got my cruise to to Nassau, Half Moon Cay and Grand Turk out of the way last week. Not going to be the same after Irma. Maybe.
I live in north central Florida, deliberately away from the coastlines. But if Mother Nature aims one right at us, nothing we can do at this point.
There is not many places worse in the US for attracting hurricanes and tropical storms except peninsular Florida and the other east and gulf coast states.
If for some reason I get wiped out in a storm, I'm moving back to Arizona where I'm from. The worst thing that happens there is 120 degrees summer days occasionally.
But hot weather doesn't destroy your home and possessions. That "dry" heat doesn't sound so bad after all compared to wind and water damage caused by a hurricane.
iv’e got to say this....the sea surface temps as applied to whether hurricanes get to cat 4 or 5 intensity has been so over blown by the media and the global warming cabal...its just not true...the upper lever out flow and shear are the main contributors. While warm surface temps are needed for any hurricane formation, (that’s why August and September are peak months after all summer for heating)...doesn’t matter if you have 200 degree SST...if you have upper level shear, you wont even have a hurricane. Harvey was the first “major” storm to hit the US in 12 years..surely over those years the oceans were very warm, yet few got that strong. Cat 5 are rare events that very seldom last very long...not because of lack of ocean heat, but the perfect upper outflow “exhaust” thats needed gets disturbed by shear and other upper level WIND currents.
Yes, you are correct. There is warm enough water around all the time for major hurricanes but the upper level conditions are rare as you point out. The other ingredient is storm internals, just having two eyewalls can keep a storm at cat 2. The eyewall replacement or transition depends on positions of bands of thunderstorms which are affected by unpredictable local factors.
In 2005, after Katrina and Rita, we were told that Global Warming was causing larger hurricanes and we should expect frequent monster hurricanes from then on. The only solution was higher taxes and more government regulation.
We then entered into a record 12 year period without a single Category 3 or higher hurricane hitting the U.S. coast. It was very inconvenient for the Global Warming industry.
12z GFS just in
misses Cuba takes a sharp turn NORTH into SE FL..nailing all the big cities in the east side of FL
Worst case
you nailed it....hurricanes are the weirdest, strangest storms on Planet Earth..theres really nothing like them. They literally have to fly planes into them every 3-5 hours to see exactly whats going on...the dynamics are so fluid and ever changing..forecasters are still clueless...they only report what they can see...not why its happening. And for left wing nuts to actually think they can affect and “stop” hurricanes is truly astonishing. These people are ^#$% crazy...good god.
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