Hurricane Isaias

[nWo]

Well I have my computer back up and running. 👍 Thanks to @swamprat for posting the threads about a couple of tropical systems. The systems that is the most interesting to me is the tropical wave behind Gonzalo. It is forecast to become a tropical depression early next week when it reaches the western tropical Atlantic. The GFS has it approaching the east coast of Florida around the first week of August.

[nWo]

Starting tomorrow I will be giving daily updates on this possible system. The latest GFS shows it possibly making landfall on the east coast of Florida as a  cat. 1 hurricane. I believe the next name on the list is Isaias. 

[sportsfan41]

As fascinating as hurricanes can be, I'm really hoping for a mild season this year.  The logistics associated with evacuating possibly millions of people, during the Covid-19 pandemic, it's scary.

[nWo]

 

 A broad area of low pressure located over the central tropical 
Atlantic continues to produce a wide area of disorganized showers 
and thunderstorms as it moves westward around 20 mph. Environmental 
conditions are forecast to be conducive for development and a 
tropical depression or tropical storm is likely to form within the 
next two or three days as the system nears the Lesser Antilles. 
Interests in the Lesser Antilles should monitor the progress of this 
system.
* Formation chance through 48 hours...high...70 percent.
* Formation chance through 5 days...high...90 percent.

[nWo]

Tuesday Morning update:

 Shower activity associated with a low pressure area located about 
750 miles east of the Windward Islands is gradually increasing 
in organization.  However, recent satellite-derived wind data 
indicate that the circulation remains broad and elongated, and the 
low does not yet have a well-defined center of circulation.  
Environmental conditions are expected to become somewhat more 
conducive for development, and a tropical depression or tropical 
storm is likely to form during the next couple of days while the 
system moves west-northwestward at 15 to 20 mph and approaches the 
Leeward Islands.

 

 

Both mid range models the Canadian and GFS are showing this system staying just off the coast of Florida over the weekend. The Canadian differs from the GFS by showing some strengthening. We are still about a week away and as we all know hurricane tracks can shift and are almost impossible to predict until we get closer to landfall. 

 

Here's the GFS model run from Friday to Sunday night.

 

This is the Canadian Model.

 

I will update again on Wednesday.

 

[nWo]

I was checking the latest data on this system. It is now Potential Tropical Cyclone Nine. Here's the latest from the National Hurricane Center:

Quote

Given the current structure of the system, only gradual
strengthening is predicted during the next day or two, however the
system is expected to become a tropical storm when it is near the
Leeward Islands on Wednesday.  After 48 hours, possible land
interaction with the Greater Antilles, and increasing south to
southwesterly shear from an upper-level trough could temper further
strengthening. The global models generally weaken the system due to
these negative factors and the NHC forecast calls for little change
in strength at the longer range.  Interests in Hispaniola, the
Bahamas, Cuba, and Florida should continue to monitor forecasts as 
changes to both track and intensity are likely. 

 

I plan on doing another update later this evening.

[nWo]

From the National Hurricane Center

Quote

 

t 500 AM AST (0900 UTC), the disturbance was centered near latitude
15.3 North, longitude 61.3 West. The system is moving toward the
west-northwest near 23 mph (37 km/h), and this general motion with
some slight reduction in forward speed is expected over the next few
days. On the forecast track, the center will move through the
southern Leeward Islands during the next few hours, near or over the
Virgin Islands and Puerto Rico tonight, near or over
Hispaniola on Thursday, and near or over the southeastern Bahamas 
on Friday.

Maximum sustained winds remain near 45 mph (75 km/h) with higher 
gusts. Some increase in strength is forecast today, with weakening 
likely on Thursday due to land interaction, and some 
restrengthening possible late week.

Environmental conditions are expected to be conducive for
additional development, and a tropical storm is forecast to form
later today.
* Formation chance through 48 hours...high...90 percent
* Formation chance through 5 days...high...90 percent

Tropical-storm-force winds extend outward up to 275 miles (445 km)
from the center. Antigua recently reported a wind gust of 47 mph 
(76 km/h).

 

[nWo]

Here are a couple of model ensembles that show there is still uncertainty on what track this system may take. The first one is the Global+Hurricane Ensembles

 

 

The second one is the GFS Ensembles

 

[nWo]

This system has been upgraded to a tropical storm with the name of Isaias. The following is from the National Hurricane Center.

Quote

At 500 AM AST (0900 UTC), the center of Tropical Storm Isaias was located near latitude 17.2 North, longitude 67.9 West. Isaias is moving toward the northwest near 21 mph (33 km/h), and a west-northwestward to northwestward motion with some decrease in forward speed is expected over the next couple of days. On the forecast track, the center of Isaias will move over Hispaniola late today and near the Southeastern Bahamas by early Friday. Maximum sustained winds are near 60 mph (95 km/h) with higher gusts. Little change in strength is anticipated until landfall in Dominican Republic later today, with re-strengthening forecast on Friday and Saturday. Tropical-storm-force winds extend outward up to 415 miles (665 km) from the center. A Weatherflow station in Yabucoa Tanque de Agua reported sustained winds of 52 mph (83 km/h) with a gust to 59 mph (94 km/h). The estimated minimum central pressure is 1003 mb (29.62 inches).

The spaghetti modeling data has shifted the possible track toward a more easterly track. 

 

 

[swamprat]

On 7/25/2020 at 5:57 PM, sportsfan41 said:

As fascinating as hurricanes can be, I'm really hoping for a mild season this year.  The logistics associated with evacuating possibly millions of people, during the Covid-19 pandemic, it's scary.

I would not hold my breath. This is the 9th named storm of the season and we are still in July. During the worst hurricane season in history, 2005 (28 total named storms), Irene, the 9th named storm became a Tropical Storm on August 7th. 

There is another tropical wave that has formed off the coast of Africa. 

 

[nWo]

28 minutes ago, swamprat said:

I would not hold my breath. This is the 9th named storm of the season and we are still in July. During the worst hurricane season in history, 2005 (28 total named storms), Irene, the 9th named storm became a Tropical Storm on August 7th. 

There is another tropical wave that has formed off the coast of Africa. 

 

Thanks for changing the title of this thread. At the moment I'm not able to do that. 

[nWo]

Isaias is now forecast to strengthen into a hurricane on Friday. For now the predicted track is for the system to stay just off the east coast of Florida. Those along the east coast should monitor this storm.

 

The spaghetti tracks are narrowing so that could mean the models are starting to get a good feel for the direction this storm will go. 

 

 

This is the GFS run from Friday night to Sunday morning. 

[nWo]

Isaias overnight has grown into a category 1 Hurricane. It may even reach cat. 2 as it approaches the east coast of Florida. For now the forecast track is for the storm to remain off the coast of Florida but uncertainty still remains as to the exact track the storm will take.

Quote

 

Maximum sustained winds are near 80 mph (130 km/h) with higher
gusts.  Some strengthening is possible today, and Isaias is 
expected to remain a hurricane for the next few days.

Hurricane-force winds extend outward up to 45 miles (75 km) from the
center and tropical-storm-force winds extend outward up to 205 miles
(335 km).

The estimated minimum central pressure is 990 mb (29.24 inches).

 

[nWo]

BULLETIN
Hurricane Isaias Advisory Number  14
NWS National Hurricane Center Miami FL       AL092020
1100 AM EDT Fri Jul 31 2020

...HURRICANE WATCH ISSUED FOR PORTIONS OF THE FLORIDA EAST COAST...
...SQUALLY WEATHER OVER THE SOUTHEASTERN BAHAMAS AND THE TURKS AND
CAICOS ISLANDS SPREADING INTO THE CENTRAL BAHAMAS...


A Hurricane Watch has been issued for portions of the Florida east
coast from north of Deerfield Beach northward to the 
Volusia-Brevard County Line.

A Tropical Storm Warning has been issued for portions of the
Florida east coast from north of Ocean Reef northward to Sebastian
Inlet and for Lake Okeechobee. 

[nWo]

The models are bringing the track of Isaias closer to the east coast of Florida. Here is the latest from the National Hurricane Center,

Quote

 

BULLETIN
Hurricane Isaias Advisory Number  15
NWS National Hurricane Center Miami FL       AL092020
500 PM EDT Fri Jul 31 2020

...HURRICANE WARNING ISSUED FOR PORTIONS OF THE FLORIDA EAST 
COAST...
...TROPICAL STORM CONDITIONS AND HEAVY RAINS CONTINUE TO SPREAD
ACROSS THE CENTRAL BAHAMAS...

SUMMARY OF 500 PM EDT...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...22.6N 75.7W
ABOUT 195 MI...320 KM SSE OF NASSAU
ABOUT 330 MI...535 KM SE OF FREEPORT GRAND BAHAMA ISLAND
MAXIMUM SUSTAINED WINDS...75 MPH...120 KM/H
PRESENT MOVEMENT...NW OR 305 DEGREES AT 15 MPH...24 KM/H
MINIMUM CENTRAL PRESSURE...991 MB...29.27 INCHES

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

A Hurricane Warning is in effect for the east coast of Florida from
Boca Raton to the Volusia/Brevard County Line.

A Hurricane Watch is in effect from the Volusia/Brevard County Line
to the Flagler/Volusia County Line and from south of Boca Raton to
Hallendale Beach.

A Storm Surge Watch is in effect for the east coast of Florida from
Jupiter Inlet to Ponte Vedre Beach.

A Tropical Storm Watch is in effect from the Flagler/Volusia County
Line to Ponte Vedre Beach.

A Tropical Storm Warning is in effect for Lake Okeechobee.

SUMMARY OF WATCHES AND WARNINGS IN EFFECT:

A Hurricane Warning is in effect for...
* Boca Raton to the Volusia/Brevard County Line Florida
* Northwestern Bahamas
* Southeastern Bahamas
* Central Bahamas

A Hurricane Watch is in effect for...
* Hallendale Beach to south of Boca Raton Florida
* Volusia-Brevard County Line to the Flagler/Volusia County Line

A Storm Surge Watch is in effect for...
* Jupiter Inlet to Ponte Vedre Beach Florida

A Tropical Storm Warning is in effect for...
* Turks and Caicos Islands
* North of Ocean Reef to south of Boca Raton Florida
* Lake Okeechobee

A Tropical Storm Watch is in effect for...
* Flagler/Volusia County Line to Ponte Vedre Beach Florida

Interests elsewhere along the southeast coast of the United States
should monitor the progress of Isaias.  Additional watches or
warnings may be required later tonight and Saturday.