Ralph's Tropical Weather-RTW

Saturday, September 2, 2017

HURRICANE IRMA UPDATE 11 PM EDT SEPT 2, 2017

...HURRICANE IRMA HEADING WESTWARD WITH 110 MPH WINDS...

ZCZC MIATCPAT1 ALL
TTAA00 KNHC DDHHMM

BULLETIN
Hurricane Irma Advisory Number  15
NWS National Hurricane Center Miami FL       AL112017
1100 PM AST Sat Sep 02 2017

...HURRICANE IRMA HEADING WESTWARD WITH 110 MPH WINDS...


SUMMARY OF 1100 PM AST...0300 UTC...INFORMATION
-----------------------------------------------
LOCATION...18.3N 46.2W
ABOUT 1030 MI...1655 KM E OF THE LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...110 MPH...175 KM/H
PRESENT MOVEMENT...W OR 260 DEGREES AT 14 MPH...22 KM/H
MINIMUM CENTRAL PRESSURE...973 MB...28.74 INCHES


WATCHES AND WARNINGS
--------------------
There are no coastal watches or warnings in effect.

Interests in the northern Leeward Islands should monitor the
progress of Irma.


DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
At 1100 PM AST (0300 UTC), the eye of Hurricane Irma was located
near latitude 18.3 North, longitude 46.2 West. Irma is moving toward
the west near 14 mph (22 km/h), and a motion just south of due
west is expected for the next 48 h.

Maximum sustained winds remain near 110 mph (175 km/h) with
higher gusts.  Some strengthening is forecast during the next 48
hours.

Irma is currently a small-size hurricane. Hurricane-force winds
extend outward up to 25 miles (35 km) from the center and
tropical-storm-force winds extend outward up to 70 miles (110 km).

The estimated minimum central pressure is 973 mb (28.74 inches).


HAZARDS AFFECTING LAND
----------------------
None


NEXT ADVISORY
-------------
Next complete advisory at 500 AM AST.

$$
Forecaster Avila

NNNN

00z MODEL GUIDANC E AND INTENSITY MODEL RUN

BRYAN NORCROSS Saturday update on HURRICANE IRMA -

Bryan Norcross added 3 new photos.

2 hrs ·

Saturday update on HURRICANE IRMA - Irma continues on track. The weather pattern for the next few days is straightforward. High pressure to the north will push the hurricane slightly south into a part of the ocean from which a number of great hurricanes have come. Hurricanes that passed within 75 miles of the NHC's 5-day forecast position include the 1926 Great Miami, 1947 Ft. Lauderdale/New Orleans, 1949 West Palm Beach, Donna, Betsy, Hugo, Frances, and Ike. And, of course, many storms went out to sea. The only lesson here is that the entire East Coast needs to be aware and ready to prepare.

The weather pattern that is expected to steer Irma when the storm is within striking distance of the East Coast is notoriously very difficult to forecast. This accounts for the constant changes in the long-range models. While a big dip in the jet stream is anticipated over the East, which will deflect Irma north, the future evolution of that dip is unknown. High pressure building across the Canada over the top of the dip makes the future steering very uncertain. Literally, anything is possible.

Irma is expected to come close enough to the northern Leeward Island, Virgin Island, and Puerto Rico that everyone there should have their hurricane plans in order. There will likely be threatening weather as Irma approaches on Tuesday into Wednesday. It is uncertain how close the core of the hurricane will come, but Watches could be issued as soon as tomorrow.

The message is similar for the Bahamas. Residents should be reviewing their hurricane plans.

There is NO credible forecast that can tell us who will be threatened on the U.S. East Coast, if anybody. There are too many variables in play. For now, enjoy the weekend, and be sure you're ready to take action if necessary. We wouldn't expect a U.S. hurricane threat until the end of next week.

NOT AN OFFICIAL FORECAST JUST MY OBSERVATION

This is why I don't want the Northern Leeward, Saba ST. Maarten, the British Virgin Islands and Puerto Rico to drop their guard. They are still in the cone of error and in danger of a direct hit. Here is one model that brings the cyclone dangerously close the the Leeward and Puerto Rico.

Also the last image shows a fairly strong northward flow in the weakness between a trough along the east coast and the Bermuda high to east. This could be the channel for Irma to track through but it still to close to the East coast and everything can change into next week. So everyone from the Florida Straits north to New York should closely monitor the progress of Irma...RTW

PUBLIC INFOMATION ON IRMA FROM N.W.S. IN MIAMI, FLORIDA

‏Verified account @NWSMiami

5pm 9/2 It's too early to know if S FL will be impacted next weekend. Review your hurricane plans this weekend just in case #flwx #Irma

LATEST BRYAN NORCROSS UPDATE

‏ @TWCBryan

Bryan Norcross Retweeted Bryan Norcross

The only message from this fact, however, is that the entire East Coast needs to be aware of developments with Irma. And have preps ready.

Check the hurrs that have passed within 75 mi of the NHC 5-day point: 1926 Miami, 1947 FTL/NOLA, 1949 WPB, Donna, Betsy, Hugo, Frances, Ike.

HURRICANE IRMA 0500 PM EDT FORECAST INFO

...IRMA MOVING SOUTH OF DUE WEST ACROSS THE CENTRAL TROPICAL ATLANTIC...

000
WTNT31 KNHC 022045 CCA
TCPAT1

BULLETIN
Hurricane Irma Advisory Number  14...Corrected
NWS National Hurricane Center Miami FL       AL112017
500 PM AST Sat Sep 02 2017

Corrected to add west in motion paragraph

...IRMA MOVING SOUTH OF DUE WEST ACROSS THE CENTRAL TROPICAL
ATLANTIC...


SUMMARY OF 500 PM AST...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...18.5N 44.6W
ABOUT 1135 MI...1825 KM E OF THE LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...110 MPH...175 KM/H
PRESENT MOVEMENT...W OR 265 DEGREES AT 15 MPH...24 KM/H
MINIMUM CENTRAL PRESSURE...973 MB...28.74 INCHES


WATCHES AND WARNINGS
--------------------
There are no coastal watches or warnings in effect.

Interests in the northern Leeward Islands should monitor the
progress of Irma.


DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
At 500 PM AST (2100 UTC), the eye of Hurricane Irma was located
near latitude 18.5 North, longitude 44.6 West. Irma is moving a
little south of due west near 15 mph (24 km/h), and this general
motion is expected to continue for the next couple of days.

Maximum sustained winds are near 110 mph (175 km/h) with higher
gusts.  Some strengthening is forecast during the next 48 hours.

Irma is currently a small hurricane, with hurricane-force winds
extending outward up to 25 miles (35 km) from the center and
tropical-storm-force winds extending outward up to 70 miles
(110 km). However, the hurricane is expected to grow in size during
the next couple of days.

The estimated minimum central pressure is 973 mb (28.74 inches).


HAZARDS AFFECTING LAND
----------------------
None


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

$$
Forecaster Beven

Note red line is latest NHC forecast track. The others are previous from the morning. You can see the NHC has had to adjust their track further to the south or left of previous track. This is due to the high pressure ridge to Irma's north curving southwestward and this forces the storm to track West of due South. That will have to watched closely, because this could change forecast for the Northern Leeward Islands and put then in harms way. This also changes the tracks further west. Keep monitoring closely and Leeward Island be ready for a hurricane if it does not shift northward...RTW

RTW TROPICAL UPDATE 0328 PM EDT SEPT 2 2017

I'm not saying this will be there when Irma gets east of the Bahamas but the low pressures and weak front moving of the coast may leave a weakness between the east coast and the Bermuda High. Of course this would mean a less chance of a South Florida landfall and an increased chance for our friends to our north. Please note this is not a forecast only my observation I can be wrong, so please keep monitoring NHC forecast closely...RTW

http://ralphstropicalweather.myfreesites.net

IRMA 12Z MODEL RUN AND OTHER ENSEMBLE MODELS GFS AND CMC MODEL RUN FROM TROPICALTIBITS

I continue to see that northward trend in the models it has been persistent and can't be ignored for those who live along the East coast.

HURRICANE IRMA UPDATE 1100 AM EDT SEPT 2, 2017

...IRMA MOVING WESTWARD ACROSS THE ATLANTIC AS A SMALL HURRICANE...

000
WTNT31 KNHC 021454
TCPAT1

BULLETIN
Hurricane Irma Advisory Number  13
NWS National Hurricane Center Miami FL       AL112017
1100 AM AST Sat Sep 02 2017

...IRMA MOVING WESTWARD ACROSS THE ATLANTIC AS A SMALL HURRICANE...


SUMMARY OF 1100 AM AST...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...18.8N 43.3W
ABOUT 1220 MI...1965 KM E OF THE LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...110 MPH...175 KM/H
PRESENT MOVEMENT...W OR 265 DEGREES AT 15 MPH...24 KM/H
MINIMUM CENTRAL PRESSURE...973 MB...28.74 INCHES


WATCHES AND WARNINGS
--------------------
There are no coastal watches or warnings in effect.

Interests in the northern Leeward Islands should monitor the
progress of this system.


DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
At 1100 AM AST (1500 UTC), the eye of Hurricane Irma was located
near latitude 18.8 North, longitude 43.3 West. Irma is moving toward
the west near 15 mph (24 km/h) and a turn toward the west-southwest
at a slightly slower rate of speed during the next two days.

Maximum sustained winds are near 110 mph (175 km/h) with higher
gusts.  Some strengthening is forecast during the next 48 hours.

Irma is a small hurricane. Hurricane-force winds extend outward up
to 25 miles (35 km) from the center and tropical-storm-force winds
extend outward up to 70 miles (110 km).

The estimated minimum central pressure is 973 mb (28.74 inches).


HAZARDS AFFECTING LAND
----------------------
None


NEXT ADVISORY
-------------
Next complete advisory at 500 PM AST.

$$
Forecaster Landsea

I added this morning 05AM track along side this morning 11AM NHC forecast track red line. Just a tad to the left of previous 05AM. If this track were to stay as is, it would make landfall anywhere from Central Florida to Florida/ GA border. These tracks will continue to change and we just need to keep watching. The Islands need to be ready in case high pressure builds over the cyclone and forces Irma into the Caribbean...RTW

06z MODEL GUIDANCE AND INTENSITY MODEL 0258 AM EDT SEPT 2 2017

IRMA'S FUTURE WIND SWATH AS OF 11 PM EDT SEPT 1, 2017

THERE HAS BEEN A GRADUAL SHIFT TO THE RIGHT WITH ARE RECENT NHC FORECAST TRACK

I ran all previous tracks that the National Hurricane Center issued since they initiated the first advisory on Irma and noticed that the present forecast in red has shift further to the right. Doesn't say much at this time, it is just an observation...RTW