Hurricane Tammy is scraping the northern half of the Lesser Antilles with tropical storm and isolated hurricane conditions through the day, while Norma is about to make landfall near Cabo as a formidable hurricane.
Hurricane Tammy scraping the Lesser Antilles
When you look at satellite, it’s kind of hard to believe that Tammy is a hurricane, but here we are!
Hurricane Tammy is just to the east of the Lesser Antilles and moving northwest. (Weathernerds.org)
Tammy has maximum winds of 80 mph, but as you can see from the satellite loop above, thankfully the majority of thunderstorm activity is east of the islands. This will help mitigate impacts a bit there through the day. However, with Tammy still having a bit of a westerly component to its track, some of that core that’s just east of Guadeloupe will probably begin to enter the islands. So from about Martinique northward, conditions could deteriorate through the day some.
Hurricane Tammy is expected to enter the islands today and exit tomorrow evening. (NOAA NHC)
The strongest winds from Tammy may occur near Antigua and Barbuda, and that’s where I’d put the highest odds of seeing some gusts closer to hurricane force. Otherwise, tropical storm conditions will impact the northern half of the Lesser Antilles. Heavy rain is also likely and flash flooding or mudslides in mountainous terrain will be a possibility.
For the Virgin Islands and Puerto Rico, the strongest winds should stay comfortably east of there, and the main concern will be rough surf, rip currents, and heavy rain. Today is another day with an elevated risk of excessive rainfall in most of Puerto Rico and the Virgin Islands.
Excessive rainfall has an elevated chance of leading to flash flooding across much of Puerto Rico and the Virgin Islands today. (NWS San Juan)
As Tammy lifts north, uncertainty in the track increases, but for the islands, conditions should improve into late Sunday and Monday.
Hurricane Norma about to make land in Cabo
Norma remains a hurricane this morning, with maximum winds of 110 mph. It is gradually weakening, but will still come ashore very soon in Cabo as a hurricane.
Norma is about to make landfall in Cabo as a formidable hurricane. (NOAA NHC)
Norma will continue off to the north and east tonight and tomorrow before dissipating over Mexico on Monday. Conditions should improve in Baja and Cabo tonight. Tropical storm conditions are expected in Sinaloa tomorrow with rain arriving earlier than that.
Tammy will impact the Lesser Antilles with gusty winds and heavy rain this weekend, while Norma clips Baja tomorrow as a fading hurricane.
Tropical Storm Tammy will scrape the northern Lesser Antilles before heading out to sea
Tammy remains a 60 mph tropical storm this morning, and it is one that is struggling a bit to really get itself in a mode to intensify quickly. That’s good news for sure, but a slow intensification remains likely, so Tammy is expected to still become a hurricane over the Leeward Islands tomorrow.
Despite having a very robust area of thunderstorms, Tammy’s center is displaced a bit to the west side of most of the activity, indicating that it’s a formidable but slightly disheveled storm. (Weathernerds.org)
You can see from the satellite image above that the majority of Tammy’s storms are displaced somewhat to the east of the center. This spares most areas for now, but that will likely change as Tammy creeps northwest.
Numerous watches and warnings are posted for the Lesser Antilles and conditions are expected to be at their worst over the next 36 to 48 hours before Tammy lifts north enough to start pulling away.
Tammy is expected to become a hurricane tomorrow as it begins to (slowly) exit the Lesser Antilles. Impacts are likely in the northern half of the island chain. (NOAA NHC)
What to expect in the northern half of the Lesser Antilles? Obviously you’ll see rough surf and some high tides there. Tropical storm force winds will approach from the south and east into tonight and tomorrow. At this time, I don’t necessarily expect much wind to get any farther west than Anguilla or St. Kitts and Nevis. Obviously, continue monitoring Tammy this weekend in Puerto Rico and the Virgin Islands, but for now any direct wind impacts seem minimal to unlikely.
With Tammy’s thunderstorm activity a bit lopsided to the east and a track taking the center near or just east of the Lesser Antilles, the heaviest of the rain will also probably stay east of most of the islands. Still, locally heavy rain is likely with flash flooding a possibility across the northern islands and even perhaps into Puerto Rico and the Virgin Islands as well. There is an elevated risk of excessive rainfall across Puerto Rico today from isolated to scattered thunderstorms. That risk may continue this weekend even with Tammy staying comfortably east of the region.
The European model rainfall forecast shows the axis of heaviest rainfall missing most of the islands, but still anywhere from 30 to 60 mm (1-2″+) of rain falling across the islands, some of which may fall quickly and produce localized flooding. (Weather Bell)
Tammy will exit north of the islands by the end of the weekend. While it’s expected to slowly head out to sea, Tammy might get left behind well north of the islands, allowing it to meander over the open Atlantic. Tammy will intensify further north of the islands until shear begins to enact a toll on Tammy next week. Despite being comfortably away from land, Tammy may continue to produce rough surf on the north-facing shores of the Caribbean islands.
Hurricane Norma has peaked but it will deliver impacts to Baja and Sinaloa
Norma has peaked in intensity and is now slowly weakening. That said, it’s still a category 3 hurricane with 115 mph maximum sustained winds.
Hurricane Norma is beginning to feel the effects of shear and slightly drier air as it comes north and a slow weakening will continue (Weathernerds.org)
Despite this downward trend in intensity, Norma is still expected to be a hurricane as it approaches Baja on Saturday. Norma will come close to making landfall in Baja before curving to the east toward mainland Mexico and coming ashore there as a tropical storm or depression.
Heading to Cabo this weekend? Check ahead to make sure everything is copacetic, but impacts there should be moderate with gusty winds and heavy rain.
Total rainfall of 4 to 8 inches is likely in southern Baja, heaviest to the north and east of Cabo, with another 3 to 6 inches possible on the coast of Sinaloa in Mexico. (NOAA WPC/Google Earth)
Rain totals are shown above for Mexico, with the heaviest rain on the southeast tip of Baja and in coastal Sinaloa.
Winds of hurricane-force are possible in Baja as Norma passes but mostly tropical storm type impacts are expected from wind.
What weather is on our radar for next week?
Next week looks a little more active across the U.S., but the tropics should settle down. Here are the things we’ll be watching.
Tropics: What exactly does Tammy do in the Atlantic? We expect Tammy to go north and out to sea, but as noted above, a handful of models do “trap” it between the Caribbean islands and Bermuda. This would not impact land at all, but it might inject some forecast uncertainty into the picture. Beyond that, we don’t expect any other real notable systems in the Atlantic or Pacific.
Rainfall: There should be a substantial amount of rain with a cold front and some moisture from Norma and the Pacific across portions of Texas into the Plains early to mid next week.
Rain totals of 4 inches or higher are possible in North Texas and Oklahoma near the Red River next week. You can also see this weekend’s heavy rain in the Northeast, locally heavy rain in the Upper Midwest, and the fingerprint of snow risk in Montana above. (Pivotal Weather)
Totals of 1 to 4 inches with isolated higher amounts seems reasonable.
Severe storms: Significant severe weather is not expected next week, but we will keep tabs on the Plains for some isolated potential with a stalled out front in the area.
Snow: There is some potential for a healthy dose of snow in portions of Montana’s mountains, specifically near Glacier National Park and the Lewis Range next Wednesday and Thursday. There’s a slight chance some of that will expand into other high terrain south and east of Glacier late next week.
Heavy snow is possible in portions of Montana midweek. (NOAA WPC)
Temperatures: Ahead of the cold front next week, we have the potential to set some record warm minimum temperatures in the Central U.S. into Texas. Nothing too extreme, but it will not feel like autumn everywhere.
Tropical Storm Tammy and Hurricane Norma strengthened overnight, but the hope is that most of their impacts will be glancing for the Caribbean Islands (Tammy) and Baja or Sinaloa (Norma) heading into this weekend.
Atlantic Tropical Storm Tammy: Strengthening and will be a close call in the Lesser Antilles
We will start today in the Atlantic, where Invest 94L leveled up to Tropical Storm Tammy yesterday. Tammy now has 60 mph winds after strengthening overnight.
Tammy is strengthening this morning, but its center remains fairly displaced to the north and west of most of the thunderstorm activity. (Weathernerds.org)
I’m not sure I’d classify Tammy as well-organized this morning, but it’s something. Whatever the case, given the higher starting point now, it won’t take much for Tammy to become a hurricane from here. Much of the northern Lesser Antilles are under tropical storm watches this morning. This includes Barbados, Dominica, Martinique, Guadeloupe, Antigua, Barbuda, Montserrat, St. Kitts, and Nevis. With the strengthening this morning, I would anticipate we see watches expanding and some hurricane watches or warnings hoisted later today.
In terms of track and impacts, Tammy will start to turn later today, first west-northwest and then northwest. Given how far south it’s starting from and how far west it already is, it will likely run into the islands before turning northward enough, meaning direct impacts are likely beginning tomorrow. Tropical storm force winds will probably arrive tomorrow morning sometime in Barbados, spreading north and west through the day. Tropical storm force winds would most likely arrive in Puerto Rico and the Virgin Islands on Saturday.
Tropical Storm Tammy is expected to scrape the northern half of the Lesser Antilles. It should track east of the Virgin Islands and Puerto Rico, but impacts are still a possibility there. (NOAA NHC)
A stronger Tammy would be more apt to turn northward a bit faster, so that may be good news for Puerto Rico, which could (should?) end up being spared any kind of meaningful wind impacts from Tammy. Still, it’s close enough, and it’s not as if there will be no impacts. The weather in Puerto Rico looks active the next couple days regardless, with excessive heat in San Juan and the north coast today and some locally strong thunderstorms and heavy downpours today and tomorrow in interior Puerto Rico. Folks should continue monitoring Tammy at least, but the hope is it will be a close miss to the east.
Heavy rain will be possible in the Leeward and northern Windward Islands with anywhere from 2 to 6 inches of rain possible. The heaviest rain will miss to the east as long as the track stays close to forecast. If Tammy does somehow track closer, as much as 8 to 10 inches of rain would be possible for some of the islands.
Beyond the islands, Tammy will continue turning north and head out to sea, looking as if it will pass well south and east of Bermuda at this time.
Pacific Hurricane Norma: Rapidly intensifying but should weaken a good bit on approach to land
Shifting west now, and we’ve had some changes overnight in Norma. As has been the case a couple times this season, rapid intensification outpaced the forecast, as Norma is now a category 3 storm with maximum winds of 120 mph.
Hurricane Norma exploded into a major hurricane overnight with winds now of 120 mph and much more classic looking structure. (Tropical Tidbits)
The good news for land is that Norma is expected to weaken as it approaches the coast of Mexico. So while we have a major hurricane now, should it track toward Baja or Cabo, it will likely not be a major hurricane there. It may still be a hurricane however or close to hurricane intensity as it approaches Baja on Saturday and Sunday. Thus, a hurricane watch was issued for Baja.
Norma is expected to slow down and weaken considerably as it approaches Baja. While it may still be a hurricane as it approaches, it will become a moisture-laden tropical storm with heavy rain possible for the southeast tip of Baja and perhaps parts of Mexico. (Tomer Burg)
Ultimately, Norma’s biggest impact may be rain. Moisture from Norma will spread northward across Mexico and probably into Texas.
Click to enlarge a map of forecast rain through next week from Mexico into Texas and the Southern Plains. (NOAA WPC/Google Earth)
Rain totals through midweek next week may approach 1 to 3 inches in much of interior Texas north into Oklahoma and Kansas. Additional rain may follow late next week with a front. So overall, while Norma is rather potent this morning, the hope is that it will bring mostly beneficial rainfall. That said, interests in Mexico, particularly Sinaloa and Baja should continue to watch Norma’s progress closely.
We’re nearing the end of the Atlantic hurricane season, but we need to continue tracking Invest 94L as it is likely to track across or near the northern end of the Lesser Antilles this weekend, including the islands Antigua and Barbuda.
Happening now: Invest 94L
There is precisely one system we need concern ourselves with in the Atlantic, and that is an area of low pressure that is approaching the Caribbean Sea. It continues to lack a center of rotation, but the system is starting to get its act together. The National Hurricane Center projects that it has an 80 percent chance of becoming a tropical depression or storm over the next week. Even if it does not the tropical system will bring heavy rains to parts of the Lesser Antilles this weekend.
Hello Invest 94L. (National Hurricane Center)
By the way, what do we mean when we say the Lesser Antilles? It can be a little confusing, both for readers and forecasters. So let’s spend a moment walking through it. We’ll start with the Greater Antilles, which are the larger Caribbean islands—Cuba, Hispaniola, Jamaica and Puerto Rico—that mark the northern boundary of the Caribbean Sea. As this arc of islands extends further eastward and to the south, the islands get smaller, places like Antigua and Barbuda, Barbados, and Saint Kitts and Nevis.
These islands stretch almost all the way south to South America, and form the eastern boundary of the Caribbean Sea. These are the “Lesser” Antilles since they’re smaller islands. To make things even more confusing, the islands of the Lesser Antilles are divided into three groups: the Windward Islands in the south, the Leeward Islands in the north, and the Leeward Antilles in the west. So Invest 94L is threatening the Leeward Islands, which are part of the Lesser Antilles. Still with me? Good. There will be a quiz at the end.
A map of the Caribbean Islands. (University of Minnesota)
The good news for the Leeward Islands is that if 94L organizes into a stronger system it is likely to turn to the northwest before reaching land. If it remains weaker, then it could follow a more westerly track into the islands, bringing some winds, high seas, and rains, but nothing too crazy. We’ll fine tune the forecast in a day or two.
What else is out there?
Not much in the Atlantic Ocean.
After 94L does whatever it does, the only other watch area over the next 10 days or so will be in the southern or southeastern Caribbean Sea, where we may see a home-grown storm develop. But that is only a vague threat at this point. And as we approach the end of October, we can generally expect to see the Atlantic tropics winding down for the year.
Here’s the quiz: Anyone got any problems with that?
