WDW Weather Forecast - August 31-Sept 16, 2016

[Strmchsr]

I'll update this first post each day with the forecast (though I'll occasionally miss a day), both long and short term. As a general rule, up to 7 days is a pretty accurate forecast, beyond that it's educated guessing and largely dependent upon how well the models are doing at that moment, which is why I call it "voodooland." If you have any specific weather questions or comments, even if it's for an area other than WDW, please post and I'll answer throughout the thread. I'll also post weather tidbits every so often. Without further delay, let's get to the forecast:

Weather at WDW - Update Wednesday pm, August 31, 2016
Look for a high of 85 today in WDW. Scattered showers and thunderstorms will begin moving in later this afternoon. Right now TD9 is almost stationary but as it lifts north the main impact from the storm will travel with it. Given the current anticipated trajectory (see below for all the details on the storm) WDW will be spared most of the impact. It is not one of the counties under a watch right now. I expect heavy rain at times but nothing too bad, and certainly nothing that would close the parks. Tomorrow, more of the same as what will probably be tropical storm Hermine approaches the coast. Look for a high 83-85 with showers and thunderstorms, some potentially quite heavy, likely. I don't think it'll be an all day rain event as the storm moves farther north. Friday will see scattered thunderstorms, but nothing consistent, with a high around 85. Saturday should be 86-88 with a 30% chance of an afternoon storm, then Sunday through Wednesday temps are back up around 90 with a 40% chance of a sea breeze storm each day.

Long range...Sept 8-16 highs stay around 90 with scattered afternoon pop up thunderstorms. No major rain issues.

Travel Issues
No major issues today, but tomorrow we could definitely see problems over central and northern Florida, including Orlando and Jacksonville, as well as southern Georgia.

Any of you who are nervous about flying, especially related to turbulence, go here and here to learn a lot about turbulence and other issues that sometimes cause anxiety when flying. Hopefully all of this will help you relax and enjoy the trip to WDW more!

Tropics Updated 8/31/16 1:00 pm CDT
Let me start with a quick update on the "other" stuff. Hurricane Gaston is back up to 120 mph winds and is a gorgeous hurricane that won't impact anyone out in the Atlantic. TD8 is now headed away from the North Carolina Coast and is likely to strengthen into a tropical storm out in the Atlantic but won't be an issue for land any longer. Invest 92L is dealing with the Saharan Dust Layer (SAL) and is not a threat to develop for a few days. Still could be an issue for the US down the road but no threat right now. Just something to watch.

Now, let's deal with the real threat. We know Tropical Storm Hermine will hit land so let's break down how things look this morning. A tropical storm warning, meaning tropical storm winds are likely within 24 hours, has been issued for the Florida Gulf Coast from the Bay/Walton County Line (including Panama City Beach) through Gulf (Port St Joe) and Franklin (Apalachicola) Counties all the way around to Pasco County (Dade City) just north of Clearwater. Leon County (Tallahassee) is also included. A tropical storm watch has also now been issued for the Atlantic coast from just south of Savannah (around Bunswick) to Jacksonville to St Augustine. A hurricane watch remains in effect for Franklin to Pasco Counties. With this large of a stretch of counties included obviously not all of them will receive tropical storm winds. But there remains some uncertainty on the track and such little time left to prepare the NHC felt it best (and I definitely agree) to warn all potential impact points. The worst of the weather will be on the eastern side of the center of circulation. Currently the NHC has Apalachee Bay near St Mark's as the "bullseye" for the storm but anyone in the warning area could be impacted. The biggest impact from this is likely to be storm surge. In some areas over 6 feet of water above ground level is forecast due to the angle of the storm, the shape of Florida and the shallow nature of the shelf water which allows the storm to pile up water in a hurry. If you live anywhere in the warning zone please check this graphic and see what the storm surge forecast is for you. You may need to head for higher ground - http://www.nhc.noaa.gov/re…/graphics...1.shtml… That's what we know. Let's dig into what's actually happening with this very frustrating storm.

The NHC upgraded TD9 to Tropical Storm Hermine with 40 mph winds at 2 pm EDT today. The overall atmosphere is conducive for further strengthening. The system has been meandering a bit because it's still poorly organized (de-coupled) an so it's not "sniffing" the trough and moving north/northeast just yet. That should happen soon. But that's why the track keeps getting adjusted slightly west. And those in Walton and Okaloosa Counties don't need to ignore this just in case a westward shift continues. Not likely, but not impossible. The models are very much zeroed in on Apalachee Bay right now but they've been initializing a little too far east so we really need to watch carefully. The NHC official forecast brings the system up to near hurricane strength with 65 mph winds at landfall. Fortunately, the really deep warm water is in the western Gulf and the wind shear will pick up considerably as the storm nears the coast and that could keep it below hurricane strength but a Cat 1 is certainly not out of the question, hence the watch. And, actually, there is strong model consensus about the winds at landfall being closer to 80 mph. The NHC is being conservative but I think the likelihood of a hurricane is increasing. As the storm surge map show, even those who aren't directly impacted by the high winds can still be dealing with serious storm surge issues and heavy rain is possible over a good chunk of the Florida peninsula tonight through Friday morning. For those on the western side, including Santa Rosa Beach, Destin, and all the way to Pensacola, occasional scattered thunderstorms are possible, and some gusty winds, but nothing major. The biggest impact will be very dangerous rip currents and folks really should stay out of the Gulf. Because the storm has slowed some landfall now looks to come late tomorrow evening or early Friday morning but that fortunately shouldn't impact any of you headed to the beach for the Labor Day Weekend. No need to adjust your plans at all.

Once the storm crosses Florida this won't be the end of the story. Georgia and South Carolina need to be prepared for tropical storm conditions Friday into Saturday. Once the storm is in the Atlantic it will track up the East Coast and could also be an issue for the coast of North Carolina. The real concern, however, is there is a decent potential for this thing to strengthen to a hurricane and curve back into the US somewhere between Delaware and Boston. I don't want to call that likely just yet, and it's definitely not a forecast, but there is potential and those of you living in those areas need to monitor this closely.

I'll update more through the day as things develop. And please don't hesitate to ask questions.

[mickeyman42]

thanks Chris, really appreciate youre level headed approach and explainations with respect to the tropics, as opposed to fear tactics or click generating forcasts

[Strmchsr]

My pleasure! I want people to be informed and prepared, but not afraid.