August may be over, but the heat will remain for Houston as a late-summer ridge of high pressure settles in over the region. There are no cold fronts in sight, alas. Meanwhile, the Atlantic season’s fifth tropical storm is forming in the southern Gulf of Mexico (it is no threat to Houston) and Hurricane Dorian has absolutely ravaged the northern Bahamas. We’ve got a lot to get to today.
Monday
There are no bones about it, today and the rest of the week will be hot beneath a ridge of high pressure. Coastal counties, such as Galveston and Brazoria, may see some showers today from the very outer bands of the tropical system deep in the Southern Gulf of Mexico, but most of the region will be hot and sunny, with highs near 100 degrees. Lows tonight will be near 80.
A hot day Monday in Texas. (Pivotal Weather)
Tuesday through the weekend
To be honest, the weather is not going to change a whole lot for Houston this week. We’re going to remain in this high-pressure driven hot-and-sunny pattern, with highs near or at 100 degrees for the remainder of this week, and likely through the weekend. Rain chances will be near zero, as we start to have some drought concerns.
Heat, how long?
The heat wave may finally break early next week, as highs fall back to more normal temperatures in the low- to mid-90s. However, the chances of a cold front during the first half of September appear to be quite remote.
Here’s the one European ensemble member that predicts a cold front. (Weather Bell)
Here’s the latest ensemble output from the European model for low temperatures through September 17. Just one member out of 50 (!) brings a notable front into Houston during that time. These are not, uhhh, good odds.
Note: This post will cover Hurricane Dorian, which presents no threat to Texas, but which we are covering due to general public interest. For Houston, there are no tropical threats for the foreseeable future. It just looks very hot with diminishing rain chances over the coming days. Our normal posts will resume tomorrow.
Hurricane Dorian has unleashed utter fury on the northern Bahamas over the last 24 hours. Great Abaco and Marsh Harbour took a direct hit yesterday while Dorian was at its peak intensity. Grand Bahama Island was hit directly overnight, and the storm’s forward motion has slowed to approximately 1 mph with the center about 30 miles northeast of Freeport.
Dorian is expected to gradually weaken a bit through the day today, though it will remain an exceptionally dangerous storm, likely of at least category 4 intensity. We are seeing signs of a possible eyewall replacement cycle underway though, which should allow the storm’s maximum winds to weaken, while the size of the wind field expands a bit. Dorian will fluctuate in intensity over the next day or two before beginning a more steady weakening trend as it lifts north later in the week.
Where is Dorian going?
Dorian’s official track forecast keeps some portion of the Florida coast in the cone, but the storm is still expected to track just offshore. (National Hurricane Center)
That remains a tricky question, but the good news if you live in Florida is that everything is basically happening the way it was expected to happen in terms of track as of this morning. Anytime a storm slows to 1 mph, there is some inherent uncertainty in the details of a track forecast. But weather modeling is almost entirely on board with a track very similar to Hurricane Matthew in 2016, as it moves up the coast just offshore of Florida, Georgia, and the Carolinas.
Dorian will be a close call in Florida and up the coast, but the vast majority of data keeps the center just offshore. (Weathernerds.org)
The latest European ensemble forecast from overnight is shown above. Again, this is just the European model run 51 different times with some tweaks in initial conditions to give a better idea of goalposts in the forecast. A few things to note. First, of the 51 ensemble members, there are still around 8 to 10 that bring the center onshore near Cape Canaveral or just south of there. While the odds aren’t high, they aren’t zero, so folks in Florida still need to be prepared. Even assuming the track stays 25 to 50 miles offshore as expected, that will still be close enough to deliver strong winds, surge, and plentiful beach erosion to the entire coast. Remember, Matthew took a similar track, and although no two storms are alike, it underscores that severe impacts can still occur without a landfall. The Florida coast will need to hunker down tomorrow through Wednesday.
As Dorian treks northward, finding its way between the high pressure over Texas and the one in the Atlantic, it will begin to accelerate. Again, this will be close to the coasts of Georgia and South Carolina, though probably still offshore. As it passes North Carolina, there will be some chance of a landfall near Cape Fear or Cape Hatteras as the storm passes. Folks in the Carolinas and Georgia should prepare for significant coastal impacts, as well as heavy rain. Again, as we saw during Matthew in these areas, significant impacts can still occur far from the actual center.
Dorian should finally exit at the end of this week, and hopefully we see no more threats to land masses for a bit.
This post concerns Hurricane Dorian, which presents no threat to Texas, but which we are covering due to general public interest. For Houston, for the foreseeable future, we can expect hot days, low rain chances, and no taste of fall.
Crossing over very warm seas and not having to battle much in the way of wind shear, Hurricane Dorian‘s maximum winds increased to 180mph on Sunday morning. As central pressures continued to fall, further intensification seems to be possible today. Unfortunately, as it is reaching peak intensity, Dorian is now beginning to cross over the northern Bahamas. Its crawling westward movement will prolong exposure on these islands to wind gusts of up to 200mph, very high seas, and heavy rainfall. Areas such as Freeport in the Bahamas will very likely see extreme levels of damage.
Hurricane Dorian official forecast track at 10am CT Sunday. (National Hurricane Center)
Beyond Monday, we still expect Dorian to make a northern turn as a trough of low pressure currently over the upper Midwest sweeps down and pulls the tropical system north. The ultimate track will depend on the timing of this trough, as well as any wobbles in Dorian’s path over the next couple of days. These two factors will determine whether the coastal regions of Florida, Georgia, and the Carolinas escape with a near miss on catastrophic conditions—which seems more likely at present—or face the brunt of Dorian’s intensity.
European ensemble model forecast for Dorian. (Weathernerds.org/Space City Weather)
Dorian probably will maintain its Category-4 and Category-5 intensity for the next couple of days as it undergoes a period of eyewall replacement cycles, when the inner eyewall weakens and then re-forms. By Tuesday or so, as it begins to pull north and at least its outer bands begin to interact with the continental United States, it should begin a weakening trend.
Hurricane Dorian exploded into a category 4 monster hurricane overnight, and it will next torment the northern Bahamas. From there, it will drift a bit more and then turn north, but exactly where that turn occurs will determine how severe the impacts are for Florida, as well as perhaps for areas farther up the coast. Let’s walk through things.
Now
One look at a satellite loop of Dorian tells you all you need to know about the storm in its present state.
Dorian is nearly a textbook major hurricane as it meanders its way toward the Bahamas. (Tropical Tidbits)
Dorian is menacing, with maximum sustained winds of 150 mph, making it a strong category 4 hurricane on the Saffir-Simpson scale. Over the next 2 to 3 days, Dorian will likely fluctuate in intensity.. But in general, expect it to remain at least a category 3, major storm. It’s not impossible to think Dorian could briefly attain category 5 status at some point. But typically, when storms get this strong, there are various ups and downs in intensification periods that are challenging to predict.
Dorian’s track
In 2016, Hurricane Matthew approached the Florida coast from the southeast. It brushed the coast but never made landfall in Florida, yet it was still a billion dollar storm for the state. In 2017, Irma approached the Keys from the southeast, while it was expected to make a sharp turn north. In that instance, 25 to 50 miles difference in where that turn occurred would mean huge differences in impacts for the entirety of the Florida Peninsula. It did approximately $50 billion in damage in what was not even close to a worst case scenario for the state. And now we have Dorian, which has been threatening a direct hit on Florida, but that has been contingent on the exact timing of a turn to the north. Multitudes of options, including a track into the Gulf or a right turn out to sea have been viable scenarios. The trend today has continued to shift toward more of a Matthew-type “brush,” as Eric discussed yesterday.
Dorian is moving west, as you see from the satellite image above. The latest NHC forecast implies that Dorian will approach the Florida coast and then turn north.
The National Hurricane Center predicts Dorian will turn north either along the coastline and just inland or just offshore. All areas in the cone should prepare for potential hurricane impacts. (NOAA)
We say it ad nauseam, but we really mean it: Do not focus on the implied track of the center here. Focus on the cone. The future track of Dorian will be contingent on the exact strength and orientation of high pressure to its north, as well as the trajectory, strength, and orientation of an upper atmospheric disturbance (trough) in the Midwest and East next week. These are all things that can change subtly in the hours and days ahead, forcing Dorian to track a few miles in one direction or another. Any shift in those expectations would have significant impacts on what conditions are experienced on the coast.
In fact, if you look at the latest spread of European ensemble members from last night’s run, you can see a wide dispersion of possible tracks.
Each line represents a possible track of Dorian’s center (impacts will extend well away from the center) over the next 6 days. While most solutions stay offshore, it’s still a very, very close call. (Weathernerds.org)
Yes, only a handful of members track the storm across Florida now. It’s not the favored outcome, but it remains a possible outcome. Again, this is why we urge folks to focus on the cone.
So Dorian should turn north after hammering the northern Bahamas. The turn north should occur either along the Florida coast or 50-100 miles offshore. Coastal impacts will still be significant, even in a miss. Dorian will generally track slowly north before eventually turning toward the northeast. Again, timing matters here because the Carolinas are in the way. It’s plausible that Dorian makes it far enough west to eventually make a landfall in South or North Carolina. We have a few extra days to iron that out. As Dorian moves north, it should slowly weaken a bit as well.
Regardless of landfall or no landfall, Dorian promises a few things: Rough surf, coastal flooding, potential surge, and beach erosion for the coast from Florida through at least North Carolina. Also, Dorian should bring a healthy amount of rainfall.
Dorian will be another big rainmaker for the coastal Southeast, with 6 to 10 inches of rain along the coast likely. (NOAA)
Rain totals should be about 6 to 10 inches along the coast from West Palm Beach to Cape Hatteras. Higher amounts are possible, and rain could extend farther inland in the Carolinas as well. Conversely, if Dorian does track farther offshore, closer to the right edge of the current forecast cone, these rain totals will be a good bit lower. But the most probable scenario right now suggests heavy rain along the coast.
Barring any significant changes today, we will update you again tomorrow morning.
Lastly, the National Hurricane Center is also assigning about a 20 percent risk of development in the southern Gulf from the disturbance we’ve discussed all week here on the blog.
There is low risk for a system to organize in the southern Gulf, but it should stay south of Texas and well south of Houston, preventing any impacts here. (NOAA)
That is currently likely to travel toward Mexico, and it is unlikely to develop significantly. We should not see any impacts in Houston from this system. There are other systems likely to develop in the far east Atlantic off Africa next week, but none of those looks like a serious concern at this time. The Gulf is expected to turn quieter for a stretch beginning later next week.
