Tropical Threats to Hawaii and Florida

There are not one, not two, but THREE tropical cyclones that are threatening the United States, namely Hawaii and Florida. First, here is a quick update on the other systems.

HURRICANE GASTON

Gaston is a Category 2 hurricane tracking east-northeastward across the northern Atlantic. Gaston could affect the Azores into this weekend as a weakening tropical storm. Here is the latest track and information from the National Hurricane Center:

SUMMARY OF 1100 PM AST...0300 UTC...INFORMATION
-----------------------------------------------
LOCATION...36.0N 45.4W
ABOUT 935 MI...1500 KM W OF FAIAL ISLAND IN THE CENTRAL AZORES
ABOUT 1020 MI...1640 KM W OF LAJES AIR BASE IN THE AZORES
MAXIMUM SUSTAINED WINDS...105 MPH...165 KM/H
PRESENT MOVEMENT...NE OR 55 DEGREES AT 20 MPH...31 KM/H
MINIMUM CENTRAL PRESSURE...970 MB...28.65 INCHES

A Tropical Storm Watch has been issued for a part of the Azores. A TROPICAL STORM WATCH means that tropical storm conditions (winds of 39-74 mph) are possible within the next 48 hours.

TROPICAL DEPRESSION EIGHT

Tropical Depression Eight is moving away from the North Carolina Outer Banks. Minimal impacts expected. Just some higher waves and dangerous rip currents expected. TD 8 is expected to merge with a front as it accelerates northeastward. Here is the latest from the National Hurricane Center:

SUMMARY OF 1100 PM EDT...0300 UTC...INFORMATION
-----------------------------------------------
LOCATION...36.7N 70.1W
ABOUT 320 MI...515 KM ENE OF CAPE HATTERAS NORTH CAROLINA
ABOUT 1110 MI...1790 KM WSW OF CAPE RACE NEWFOUNDLAND
MAXIMUM SUSTAINED WINDS...30 MPH...45 KM/H
PRESENT MOVEMENT...ENE OR 65 DEGREES AT 18 MPH...30 KM/H
MINIMUM CENTRAL PRESSURE...1010 MB...29.83 INCHES

Now, lets start talking about the threats to Hawaii.

TROPICAL STORM MADELINE

Madeline has weakened from a major hurricane yesterday back to a tropical storm now. However, Hawai'i as a whole is not accustomed to hurricanes or strong tropical storms. So this is a serious threat. Here is the latest information and track for Hurricane Madeline from the Central Pacific Hurricane Center:

SUMMARY OF 500 PM HST...0300 UTC...INFORMATION
----------------------------------------------
LOCATION...18.0N 155.1W
ABOUT 115 MI...190 KM S OF HILO HAWAII
ABOUT 290 MI...470 KM SE OF HONOLULU HAWAII
MAXIMUM SUSTAINED WINDS...65 MPH...100 KM/H
PRESENT MOVEMENT...WSW OR 250 DEGREES AT 12 MPH...19 KM/H
MINIMUM CENTRAL PRESSURE...998 MB...29.47 INCHES

There is a TROPICAL STORM WARNING for the islands of Hawai'i, Maui, Molokai, Lanai, and Kahoolawe. 

• TROPICAL STORM WARNING - tropical storm conditions (winds of 39-74 mph) are expected within the next 36 hours

Strong winds, heavy rain, and dangerous surf are expected along the southern islands of Hawai'i. The worst effects will be felt along the Big Island.

MAJOR HURRICANE LESTER

Lester is a Category 3 hurricane moving off toward the west across the central Pacific. The hurricane is expected to weaken as it approaches Hawai'i this weekend. Here is the latest information for Hurricane Lester from the National Hurricane Center:

SUMMARY OF 500 PM HST...0300 UTC...INFORMATION
----------------------------------------------
LOCATION...18.2N 141.2W
ABOUT 915 MI...1470 KM E OF HILO HAWAII
ABOUT 1105 MI...1780 KM E OF HONOLULU HAWAII
MAXIMUM SUSTAINED WINDS...120 MPH...195 KM/H
PRESENT MOVEMENT...W OR 280 DEGREES AT 14 MPH...22 KM/H
MINIMUM CENTRAL PRESSURE...959 MB...28.32 INCHES

Much of the state of Hawai'i is in the projected path. But, again, main threats look to be increased surf, high winds, and heavy rainfall. Tropical Storm Watches or Hurricane Watches may be required as we head into the day Thursday.

TROPICAL STORM HERMINE

Tropical Depressoon Nine strengthened into Tropical Storm Hermine at 1 PM CDT after the Hurricane Hunters found sustained tropical-storm force winds. It is getting better organized, and Hermine is expected to strengthen until landfall. Here is the latest track and information from the National Hurricane Center:

SUMMARY OF 1000 PM CDT...0300 UTC...INFORMATION
-----------------------------------------------
LOCATION...25.8N 87.0W
ABOUT 295 MI...475 KM SSW OF APALACHICOLA FLORIDA
ABOUT 315 MI...510 KM WSW OF TAMPA FLORIDA
MAXIMUM SUSTAINED WINDS...60 MPH...95 KM/H
PRESENT MOVEMENT...NNE OR 25 DEGREES AT 10 MPH...17 KM/H
MINIMUM CENTRAL PRESSURE...998 MB...29.47 INCHES

Now, there are a lot of watches and warnings in effect. The map above only shows the coastal watches and warnings. I will provide the counties under the Tropical Storm/Hurricane Watches/Warnings (as of 10 PM CDT):

• HURRICANE WARNING: [in Florida]: Gulf, Gadsden, Liberty, Franklin, Leon, Wakulla, Jefferson, Madison, Taylor, coastal Dixie
• TROPICAL STORM WARNING: [in Florida]: Levy, Citrus, Hernando, Pasco, Walton, Holmes, Washington, Bay, Jackson, Calhoun, inland Dixie, [in Georgia]: Seminole, Decatur, Grady, Thomas, Brooks, Lowndes, Early, Miller, Baker, Mitchell, Colquitt, Cook, Lanier, Clay, Calhoun, Dougherty, Berrien, Worth, Tift, Turner, Irwin, Ben Hill, Quitman, Terrell, Randolph, Lee, [in Alabama]: Geneva, Houston, Henry
• HURRICANE WATCH: [in Florida]: south Walton, Bay, Calhoun, Gulf, Gadsden, Liberty, Franklin, Leon, Wakulla, Jefferson, Madison, Taylor, coastal Dixie, coastal Levy, coastal Citrus, coastal Hernando, coastal Pasco
• TROPICAL STORM WATCH: [in Florida]: Hamilton, Suwannee, Columbia, Baker, Nassau, Duval, Union, Bradford, Clay, St. Johns, Gilchrist, Alachua, Putnam, Marion, [in Georgia]: Coffee, Jeff Davis, Bacon, Appling, Wayne, Atkinson, Ware, Pierce, Brantley, Glynn, Echols, Clinch, Charlton, Camden, Washington, Glascock, Jefferson, Twiggs, Wilkinson, Johnson, Emanuel, Schley, Macon, Peach, Houston, Bleckley, Laurens, Treatment, Sumter, Dooly, Crisp, Pulaski, Wilcox, Dodge, Telfair, Wheeler, Montgomery, Toombs, Screven, Jenkins, Effingham, Bulloch, Candler, Tattnall, Evans, Long, Liberty, Bryan, Chatham, McIntosh, [in South Carolina]: Allendale, Hampton, Jaspee, Colleton, Beaufort, Dorchester, Charleston, Berkeley

Now, the National Hurricane Center has also released an experimental product (which will become operational next year. There is a STORM SURGE WARNING for areas from near Indian Pass to near Spring Hill. A Storm Surge Warning mean that life-threatening storm surge and inundation is expected within the warning area.

Now, this is the reasonable worst-case storm surge flooding, most areas along the Big Bend and northern west coast will see at least 1 foot of storm surge flooding. Within the Big Bend, it's not out of the question to see 3 to 6 feet of storm surge flooding. And this does not include waves on top of that surge. It is highly recommended that if you live in these areas that you seek higher ground.

Even outside of these areas, coastal flooding can still occur, especially near high tide. There is a high risk of rip currents and also high surf. Heavy rainfall is occurring along the west coast of Florida and is expected to continue. Most of the effects will be on the east side of the system, so it is important not to focus on just the cone. If you are under a Tropical Storm Warning, you need to have your emergency preparedness kit ready to go. Heed all evacuation orders. If you are under a Tropical Storm Watch, you need to be stocking your emergency preparedness kit and be ready to use it if necessary. Monitor local officials, and official sources such as NOAA, NWS, NHC, etc. For everyone, be prepared for power outages under a Tropical Storm Watch or Warning. Tornadoes are possible across much of north central Florida into southeastern Georgia.

Stay safe, be prepared, and monitor local sources.

Useful links:
National Hurricane Center: website, Facebook, @NWSNHC, @NHC_Atlantic, @NHC_Pacific
Central Pacific Hurricane Center: website
NWS Honolulu: website, Facebook, Twitter
NWS Tallahassee: website, Facebook, Twitter
NWS Tampa Bay: website, Facebook, Twitter
NWS Jacksonville: website, Facebook, Twitter
NWS Peachtree City: website, Facbook, Twitter
NWS Charleston: website, Facebook, Twitter

Definitely Active in the Tropics

We've had quite a bit of hype from several sources about former-Invest 99L, but shortly after we got a tropical depression upgrade in the Florida Straits (more on that later), articles like this started popping up.

And this comes from a reputable news source! Several meteorologists, storm chasers, and others quickly squelched this article, and NBC Nightly News quickly removed the tweet. But this just shows you, watch where you get your information from! Even reputable news sources are guilty of posting these articles. It's a classic example of fearmongering and clickbaiting. Just beware! You can read my post about over-hyping here.

Now that that's out of the way, let's move forward with the tropics, as there really is a lot going on.

Our first stop takes us to the central and eastern Pacific. Why out here? Well there are potential threats to Hawai'i over the coming days. We will start with the closes storm to Hawai'i.

MAJOR HURRICANE MADELINE

This is Madeline churning over the central Pacific. Here's the latest from the National Hurricane Center:

SUMMARY OF 1100 AM HST...2100 UTC...INFORMATION
-----------------------------------------------
LOCATION...18.6N 145.5W
ABOUT 630 MI...1015 KM E OF HILO HAWAII
ABOUT 825 MI...1330 KM E OF HONOLULU HAWAII
MAXIMUM SUSTAINED WINDS...115 MPH...185 KM/H
PRESENT MOVEMENT...WNW OR 300 DEGREES AT 10 MPH...17 KM/H
MINIMUM CENTRAL PRESSURE...966 MB...28.53 INCHES

Madeline is a Category 3 Hurricane moving to the west-northwest. A Hurricane Watch is in effect for the island of Hawai'i. Gradual weakening is expected, and Madeline is expected to pass near the island of Hawai'i as a gradually weakening hurricane.

Models are a bit spread as Madeline approaches Hawai'i. Right now, if it makes landfall, it would likely be on the island of Hawai'i. But there is a good amount of guidance that takes it further south. Either way, heavy rain, gusty winds, and increased surf are possible with Madeline.

MAJOR HURRICANE LESTER

This is Hurricane Lester in the eastern Pacific, well away from any land right now. Here's the latest from the National Hurricane Center:

SUMMARY OF 200 PM PDT...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...18.0N 130.5W
ABOUT 1375 MI...2210 KM W OF THE SOUTHERN TIP OF BAJA CALIFORNIA
MAXIMUM SUSTAINED WINDS...130 MPH...215 KM/H
PRESENT MOVEMENT...W OR 270 DEGREES AT 14 MPH...22 KM/H
MINIMUM CENTRAL PRESSURE...951 MB...28.09 INCHES

Right now, Lester is a strong Category 4 major hurricane. Intensity forecasts show that Lester will start to weaken as it approaches Hawai'i, but still keeping it a hurricane. The projected path brings it closer to Hawai'i in 5 days as a hurricane.

In the long range, the models tend to keep Lester north of the Hawaiian Islands. However, yet again, heavy rain and increased surf will be the main threats. Now, if either Lester or Madeline make landfall on any of the Hawaiian Islands, it would be the second tropical cyclone to make landfall (Darby was the first in July).

Now, let's move to the Atlantic.

DISTURBANCE IN THE NORTHWEST GULF OF MEXICO

A weak area of low pressure near the Texas coast will wander southwestward, but it should not develop. Heavy rain will be the main threat in southeastern Texas. The latest outlook from the National Hurricane Center says:

A weak trough of low pressure located just offshore of the central
coast of Texas is producing disorganized showers and a few
thunderstorms over the northwestern Gulf of Mexico and adjacent
coastal areas.  Proximity to land and only marginally favorable
upper-level winds are expected to inhibit development while the
system drifts southwestward during the next day or so.  For
additional information on the rainfall associated with this system,
please see products from your local National Weather Service office.
* Formation chance through 48 hours...low...10 percent
* Formation chance through 5 days...low...10 percent

HURRICANE GASTON

At 4 PM CDT Sunday, Gaston became the first major hurricane (Category 3 or higher) of the 2016 Atlantic Hurricane Season. It has weakened a bit since then. Here's the latest from the National Hurricane Center:

SUMMARY OF 500 PM AST...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...31.2N 55.2W
ABOUT 570 MI...915 KM E OF BERMUDA
ABOUT 1665 MI...2675 KM W OF THE AZORES
MAXIMUM SUSTAINED WINDS...105 MPH...165 KM/H
PRESENT MOVEMENT...NNE OR 30 DEGREES AT 3 MPH...6 KM/H
MINIMUM CENTRAL PRESSURE...968 MB...28.59 INCHES

Gaston is a strong Category 2 hurricane, and it's expected to slowly weaken back to tropical storm status as it approaches the Azores this weekend.

Models are in pretty good agreement through the next several days as Gaston makes that turn toward the northeast. The only threat to land could be the Azores late next week, but a lot can change between now and then.

TROPICAL DEPRESSION EIGHT

Well, Tropical Depression Eight is encountering some strong shear, leaving the system lopsided. The shear is going to help keep TD 8 in check. Right now, here is the latest from the National Hurricane Center:

SUMMARY OF 500 PM EDT...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...33.6N 74.0W
ABOUT 140 MI...225 KM SE OF CAPE HATTERAS NORTH CAROLINA
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H
PRESENT MOVEMENT...NW OR 310 DEGREES AT 6 MPH...9 KM/H
MINIMUM CENTRAL PRESSURE...1011 MB...29.86 INCHES

Tropical Storm Warnings are in effect for the Outer Banks of North Carolina from Cape Lookout to Oregon Inlet and also for Pamlico Sound. A Tropical Storm Warning means that that tropical storm conditions (sustained winds of 39 mph or greater) are expected within the next 36 hours. However, even if TD 8 doesn't make landfall, most of the showers and storms will be on the west side of the system. Also, it appears that TD 8 will not become a particularly strong tropical storm. But, heavy rain, rough surf, and deadly rip currents will be possible for portions of coastal North Carolina.

Anything after 72 hours is the result of TD 8 losing its identity and merging with a front. But, models are in decent agreement about bringing TD 8 close to the North Carolina coast before being swept out into the far north Atlantic.

TROPICAL DEPRESSION NINE

After about 11 days of tracking this system as Invest 99L, it finally became a tropical depression Sunday afternoon after the Hurricane Hunters found that former-99L had a well-defined closed circulation. Now, that does not mean it's well-organized. It has been battling wind shear, but that is starting to subside as TD 9 moves into the Gulf of Mexico. Right now, the main thing that TD 9 is battling is some dry air. Here's the latest from the National Hurricane Center:

SUMMARY OF 500 PM EDT...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...24.0N 84.8W
ABOUT 195 MI...310 KM WSW OF KEY WEST FLORIDA
ABOUT 160 MI...260 KM WNW OF HAVANA CUBA
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H
PRESENT MOVEMENT...WNW OR 290 DEGREES AT 5 MPH...7 KM/H
MINIMUM CENTRAL PRESSURE...1007 MB...29.74 INCHES

The National Hurricane Center notes that a Tropical Storm or Hurricane Watch may be required for a portion of the Florida Gulf Coast. Now, TD 9 actually took a dive to the west-southwest Sunday evening as it was interacting with Cuba. Most of the time, land is not a good thing for tropical cyclones. But sometimes, it can help the circulation a bit. With the friction caused by land, TD 9's circulation was able to tighten up on the southern side and convection to flare up on the southern side of its circulation. This allowed for TD 9 to move a bit more to the west-southwest. But, it has since started moving toward the west. Eventually, TD 9 is expected to turn more toward the northwest and then to the north. Then, a cold front (the same one expected to sweep away TD 8) will cause TD 9 to turn toward the northeast. Where and when all these turns occur will ultimately determine where TD 9 will make landfall. The current forecast from the National Hurrican Center calls for a strong tropical storm to make landfall somewhere between Port St. Joe and Sarasota.

These are the possibilities of seeing tropical storm force winds (sustained winds greater than or equal to 39 mph). Right now, the best chance looks to be between Port St. Joe and Tampa. Again, a lot can change between now and Thursday (when this could make landfall).

Let's look at the models and see what they're saying:

The one thing that models agree on is that TD 9 will eventually turn toward the northeast, but they greatly differ on when that turn will occur, so the models are really spread from Pensacola to Fort Myers. Again, still need to watch this system anywhere in Florida.

Let's look at our two most reliable models (GFS and ECMWF):

This is the 12Z (7 AM CDT) run of the GFS from Monday morning. This run is generally in the middle of all the guidance, but may have trended a touch north with a landfall southwest of Perry as a tropical storm. Again, this is just one run of one model. But let's look at the ECMWF.

The ECMWF is stronger than the GFS, but essentially the same track. However, the ECMWF, like the GFS, also has trended just slightly more west and north compared to the last run. And this slight shift westward can be seen in our model ensembles.

Ensembles (in this case, the GEFS) are the same model (in this case, the GFS) run with slightly different initial conditions. These alterations in the initial conditions help provide a range of possibilities. On the map above, all of the tiny red numbers near the Florida Panjandle are different positions for TD 9. There is a bit more cluster near Panama City and Apalachicola. This is just something to monitor as we go forward in time.

Note that even a strong tropical storm can cause storm surge issues in the Big Bend of Florida. That area is one of the most storm surge prone areas in the United States. The storm is likely to be lopsided due to some shear, so most of the impacts will be felt on the eastern and southeastern side of the system. Heavy rain, gusty winds, dangerous surf, elevated tides, some storm surge, and deadly rip currents are all possible threats which will be fine tuned as we move forward.

TROPICAL WAVE COMING OFF OF AFRICA

There is a pretty strong tropical wave coming off the coast of Africa into the tropical Atlantic and moving near the Cabo Verde Islands. This is the latest from the National Hurricane Center:

A tropical wave is expected to move offshore of the west coast of
Africa tonight.  Conditions are expected to be favorable for gradual
development of this system later this week while it moves westward
at 15 to 20 mph over the tropical Atlantic.
* Formation chance through 48 hours...low...near 0 percent
* Formation chance through 5 days...medium...50 percent

The above animations are the GFS (top) and ECMWF (bottom) out to 7 AM CDT September 3rd. Both models generally agree that this wave (probably will be designated Invest 92L) will move westward across the tropical Atlantic. However, it is way too far out to speculate what will happen beyond 5 days.


Now, remember to get all your information from official sources (NOAA, NWS, NHC, etc.). You can find detailed information about watches and warnings from your local National Weather Service office here. The latest tropical cyclone information (and where I got several of the graphics in this blog) can be found here. Follow the direction of your local officials and emergency management for preparation tips and evacuation information (if it becomes necessary). Make sure your emergency preparedness kit is stocked at all times.

Also, credits to Levi Cowan's website for the model graphics.

An Active Atlantic, Typical for Late August

So, if you're not quite fatigued from hearing about Invest 99L yet, then you may be after you see all the systems we are watching now. First, we will start with a system that is already named... Gaston.

TROPICAL STORM GASTON

Gaston has been fighting off some wind shear over the past couple of days, it is starting to re-strengthen yet again. Thankfully, Gaston is expected to remain over the open waters of the Atlantic and not impact any land areas directly over the next 5 days.

As you can see, Gaston will not be making landfall anywhere through at least the next 5 days, but it will become a hurricane yet again as it moves over the open Atlantic.

DISTURBANCE IN THE NORTHWEST GULF OF MEXICO

The disturbance being monitored here is just off the coast of Texas and Louisiana. This trough of low pressure has a near zero chance of development as it moves onshore Sunday. This is the latest from the National Hurricane Center:

A weak trough of low pressure located south of the coast of
southwestern Louisiana is producing disorganized shower and
thunderstorm activity over the north-central Gulf of Mexico.
Conditions are not expected to be conducive for development before
this system reaches the coast of Texas on Sunday.  However, heavy
rainfall is possible along the Gulf Coast from Louisiana to
southeastern Texas during the next few days.  For additional
information, please see products from your local National Weather
Service office.
* Formation chance through 48 hours...low...near 0 percent
* Formation chance through 5 days...low...near 0 percent

While it isn't expected to develop, we are looking at more unwanted rain for southern Louisiana and southeastern Texas.

INVEST 91L

Yes, we do have another area of investigation from the National Hurricane Center. This is 91L located to the southwest of Berumda. It has a pretty vigorous low level circulation, but the convection is being sheared.

The latest from the National Hurricane Center says:

A broad area of low pressure located about 140 miles southwest of
Bermuda is producing winds of 30 to 35 mph.  Shower and thunderstorm
activity has not become any better organized during the past few
hours, and significant development of this system is likely to be
slow to occur due the proximity of dry air during the next couple of
days while it moves westward and then west-northwestward at about
10 mph toward the coast of North Carolina.  After that time,
increasing vertical wind shear is expected to make development
unlikely.  For additional information on this system, see High Seas
Forecasts issued by the National Weather Service.
* Formation chance through 48 hours...low...30 percent
* Formation chance through 5 days...low...30 percent

Models generally agree on taking 91L west-northwestward toward the North Carolina coast and Outer Banks before slinging it back out into the Atlantic. If 91L develops, it probably won't be anything too strong, but it will likely bring some heavy rainfall to parts of North Carolina.

INVEST 99L

Yes, we are still talking about this thing. Bless its heart. It really is trying. It actually looks better than it has in recent days, but looks can be a bit deceiving. Some observations from earlier suggest that a low-level circulation was trying to form, but it was displaced from the mid-level center, shearing some of the convection. Also, now we have thunderstorms firing over Cuba, part of the daytime hearing, which is taking away energy from 99L. So, development chances, for right now, don't look all that great. The latest from the National Hurricane Center says:

A weak area of low pressure located between the northern coast of
Cuba and Andros Island in the Bahamas continues to produce a large
area of disorganized showers and thunderstorms, mainly to the south
and east of its center.  Upper-level winds are not conducive for
significant development during the next day or so while the low
moves west-northwestward through the Straits of Florida at about 10
mph.  Environmental conditions could become a little more conducive
for some development when the system moves into the eastern Gulf of
Mexico early next week.  Heavy rains are likely to continue over
portions of eastern and central Cuba today.  Gusty winds and locally
heavy rainfall are likely over portions of the Bahamas, and will
spread into parts of southern Florida and the Florida Keys by
Sunday.  Interests elsewhere in Florida and the eastern Gulf of
Mexico should continue to monitor the progress of this disturbance.
The Hurricane Hunter aircraft mission scheduled to investigate this
system today has been canceled.
* Formation chance through 48 hours...low...30 percent
* Formation chance through 5 days...medium...40 percent

So, while development chances are lower than they have been, they still are not zero. You can never say never when it comes to the tropics in late August. Now, it looks a little better, but does that mean we have a little better handle on where it's going?

For the first 48 hours, somewhat yes. After that, still no idea. We are pretty confident that 99L will pass through the Florida Straits into the southeastern Gulf of Mexico. After that, as has been the case for the last several days, the models wildly diverge in both track and intensity. Now, the one thing the models do agree on is that there will be a more favorable environment for some sort of possible development. So, it is possible for 99L to get into the Gulf and try to organize itself. But, once again, we are still talking about a system that is not organized. So, really, the models cannot be fully trusted beyond 48 hours, giving us a rather low confidence in any sort of forecast. Our two most reliable models (GFS and ECMWF) have been at odds with each other for a while now. Let's take a look at their 00Z runs from last night.

So, on top we have the 00Z GFS running out through 7 PM Sept. 1, and below it we have the 00Z ECMWF running out through the same time. Now, neither the GFS or the ECMWF really develop 99L. The GFS actually splits 99L with part of the energy left drifting west in the Gulf of Mexico and another part developing off the northeast coast of Florida.

The ECMWF doesn't really develop it either. It kind of makes 99L an elongated system that extends from the central Gulf into the southeast. Somewhat similar, a d both showing weak solutions. So, small victories for some agreement, right? Now, let's see if the models changed 12 hours later.

So, these are the 12Z runs of the GFS (top) and the the ECMWF (bottom). No the go out to 7 AM Sept. 1. Let's look at the GFS first. The GFS is a little stronger with this run than its 00Z run. It takes 99L up the west coast of Florida, then sort of merges it with 91L before sending it out to sea.

The ECMWF is a completely different story. It shows 99L a good bit stronger than the GFS's runs and its own 00Z run. It takes 99L west into the central Gulf and kind of stalls it. There are reasons I'm not showing beyond this time frame:

1. It's beyond 5 days out.
2. The end of the 12Z run of the ECMWF probably should not be seen.

But, the GFS has one thing going for it. It has decent run-to-run consistency. I won't say it's good, but it's okay. It continues to show something weak that (at least in part) affects the west coast of Florida. The ECMWF does not have good run-to-run consistency. It keeps jumping from weak to strong and shifting the track back and forth.

However, the models can and will change, as we've seen over the past several days. I think once it gets into the Gulf, we will have a better idea of what it will do.

TROPICAL WAVE COMING OFF OF AFRICA NEXT WEEK

Nope, we aren't through yet. We now turn our attention to western Africa for the next potential tropical system.

So, I know I told you I didn't want to show you anything past Day 5 on models, but I'm going to break that rule here. There has been some good agreement on a tropical wave emerging from Africa on Tuesday. Above are the 12Z GFS (top) and ECMWF (bottom) out to 7 AM Sept. 6. Now, the models have consistently shown this and are in pretty good agreement out to Day 8 or so, which is pretty rare. But, if this wave holds together, there are pretty good indications that it could develop into the next named storm (Hermine, Ian, or Julia, depending on if 99L and/or 91L get named). This is still about 3 to 5 days out,  it this is what the National Hurricane Center is saying:

A tropical wave is expected to move offshore of the west coast of
Africa on Tuesday.  Conditions appear favorable for development of
this system later next week while it moves westward at 15 to 20 mph.
* Formation chance through 48 hours...low...near 0 percent
* Formation chance through 5 days...low...30 percent

So, again, with all this said, just stay up-to-date with your official sources. Anything can change, but just stay aware and stay prepared as we are now (basically) in the peak of hurricane season.


Again, credits go to Levi Cowan and his website, Tropical Tidbits, for all the forecast images.