October 18, 2023 Outlook: Another tropical system is likely to form and threaten the Lesser Antilles

One-sentence summary

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?

October 17, 2023 Outlook: Invest 94L still may develop, while Invest 90E in the Pacific will likely develop and eventually track toward Mexico

One-sentence summary

Invest 94L is slightly better organized this morning in the Atlantic but still has a long way to go to develop, while Invest 90E is likely to develop today or tomorrow and will eventually be a concern for Mexico.

Tropics: Invest 94L

Thunderstorm activity improved around Invest 94L yesterday evening, and this morning, while it’s clearly heavily sheared, it actually has a bit of a nascent organizational “shape” to it.

Invest 94L, while heavily sheared this morning, is at least maintaining robust thunderstorm activity, a necessary precursor to development. (Weathernerds.org)

There’s clearly still a long way to go here, but 94L is at least taking baby steps toward organization today. Whether or not it maintains those baby steps or throttles back in reverse remains to be seen.

The track forecast has not changed much for 94L’s future. In general, if it can get its act together over the next day or two, there’s a good chance it will start to shift northwest faster. If it remains a discombobulated mess, it will probably track toward the islands with some impacts, albeit most likely on the lower-end of the intensity spectrum.

Invest 94L should track west or west-northwest toward the islands, unless it develops quickly, in which case it would follow the northern edge of that track density plot. (Tomer Burg)

This remains a system to keep an eye on in the Caribbean islands, but probably nothing to worry a ton over still at this point. We’ll continue to watch it closely through the week.

Pacific Invest 90E

Meanwhile, in the other ocean, Invest 90E is on the cusp of developing into a tropical depression or storm.

Invest 90E (center) is likely to become a depression or storm in the next 24 hours or so. (Weathernerds.org)

Invest 90E is a little more intriguing from a potential impact standpoint, as this is expected to organize rather considerably and track toward Mexico. This bears watching from southern Baja to northern Jalisco and Puerto Vallarta in Mexico.

Next significant U.S. weather event? Not for a bit

With a quiet stretch ongoing across the country much of this week, the question is: When will we experience our next significant weather event? Well, we may be looking at another 1 to 3 inches of rain this weekend in parts of the Northeast, an area that has seen below normal rain in portions of New Hampshire and Vermont and almost 200 percent of normal rain in portions of Southern New England and near New York City.

Rainfall since mid-August has been dramatically above normal in Southern New England and in the NYC metro, while it has varied in northern New England and across Upstate New York. Another 1 to 3 inches is expected this weekend. (High Plains Regional Climate Center)

So how wet your soils are depends a bit on where you live in the Northeast or parts of the Mid-Atlantic. I would suspect 1 to 3 inches of rain wouldn’t cause any serious flooding issues, but it’s something to watch.

Record warmth

California is set to experience a couple days of near record and record warmth for mid to late week. Thursday’s forecast highs show records in a few spots in interior California from east of San Diego all the way north to Medford, Oregon.

Any location boxed in on the map above is expected to see a record high temperature on Thursday. (Weather Bell)

Weak to moderate offshore winds will also help keep temps up overnight, allowing many locations to set or tie record warm minimum temperature levels on Wednesday night and Thursday night. Some of that record warmth will expand into the Desert Southwest and Texas heading toward the weekend.

But truthfully, aside from these items, it’s a quiet stretch for autumn here in the States. I suspect we will want to watch the Pacific tropical system and a potential cold front later next week for some more significant weather chances, but that’s a long way off. For now, enjoy the quiet.

October 16, 2023 Outlook: Invest 94L has a muddy future in the Atlantic, while the Pacific heats up a little

One-sentence summary

Invest 94L in the Atlantic is struggling as it continues to plod west toward the Caribbean, while Invest 90E in the Pacific has some potential to develop and impact Mexico in the next 7 to 10 days.

Tropical Outlook: Invest 94L’s on-again/off-again potential

It’s been interesting to watch Invest 94L over the last several days. We’ve seen cycles of model runs that are quite bullish on development, followed up by cycles of model runs that are not. We are currently in the latter, where model support has waned for Invest 94L’s development. That’s not say it’s impossible (the NHC still gives it 70% odds over the next week), but it is not looking nearly as robust as it did late last week.

Thunderstorm activity around Invest 94L is not exactly organized this morning. (Weathernerds.org)

On satellite this morning, you can see the convection (thunderstorm activity) this morning around 94L struggling a bit. There is no organization to this. It looked far better on Saturday, then collapsed yesterday. And here we are. Over the next 2 to 3 days it should plod west and will probably wax and wane in organization.

The total density track plot for 94L as of yesterday showed a broad track toward the Lesser Antilles, but low confidence in how much development we’d see on that path. (Tomer Burg)

Folks in the islands probably want to continue to monitor the progress of 94L, as it almost certainly tracks in that direction. Overall, 94L certainly looks less menacing than last week. But it still has a chance at becoming a tropical storm or better. Beyond the islands, 94L would probably turn north and eventually out to sea, assuming it organizes. We’ll keep an eye on it this week.

Elsewhere, Sean finally met its demise late last night. Sean tied for the 6th least amount of generated ACE this season in the Atlantic meaning it was not much of a storm. There are no current signs of any further activity behind Sean’s remnants and Invest 94L at this time.

Pacific outlook

The most interesting of the potential tropical systems in the Atlantic or Pacific is probably in the Pacific. Invest 90E seems likely to develop over the next couple days as it meanders over the open Pacific. Steering currents do suggest that this one will shift back north and eventually east toward the coast of Mexico at some point, so this bears close watching there.

From the Euro ensemble overnight, you can see a pretty basic calculus for Invest 90E. If it develops with some potency, it will likely turn north or northeast back toward Mexico. If it struggles, it may meander south of Baja offshore. (Weathernerds.org)

Much like in the Atlantic, a weaker storm would probably plod farther out to sea, whereas one that organizes more quickly would be apt to turn north and eventually northeast. Right now, given that 90E has pretty robust thunderstorm activity, the money may be on the latter outcome. We’ll see what we’ve got here over the next few days.

U.S. Weather update: Quiet but warming

We will have a pretty quiet week across the country this week, with no real serious weather to speak of. We will likely have some warm temperatures building out of the West, with some record highs and a number of record warm minimum temperatures later in the week.

Temperatures will begin the week cool in the East, but building warmth in the Western U.S. is likely to spread eastward as the week goes on. (Weather Bell)

Otherwise, it looks pretty quiet for most of this week across the country!

October 13, 2023 Outlook: A solar eclipse viewing forecast, plus watching potential Atlantic trouble next week

One-sentence summary

Decent viewing is expected for this weekend’s solar eclipse, with a few exceptions, while we have a few days to check on Invest 94L before it develops and potentially becomes a troublemaker in the Atlantic.

Tropics: Invest 94L emerges as a potential troublesome late season pest in the Atlantic

Tropical Storm Sean regrouped yesterday, but it is expected to gradually fade away as it turns northwest over the next few days.

Behind Sean, however, lurks our next system. I was hoping we might have a couple days to chill out before we started really following this one, but here we are. Invest 94L is nothing to look at right now, and it only has a very low chance to develop into anything over the weekend. But as we go into next week, the odds are beginning to increase that something will come of this.

Over the next 7 to 10 days, Invest 94L is expected to trek west or just north of due west while only slowly developing. (Tomer Burg)

While we’re a long way from having to actually worry about this, there’s enough potential there to say this is going to be worth watching. As Sean exits, the central Atlantic is going to fill up with a pretty beefy ridge of high pressure. Winds turn clockwise around high pressure, which means, 94L will be generally directed due west with minimal latitude gain over the next several days. Wind shear may or may not begin to lighten up a bit on its track as well, and that will help determine what upside there is to this system.

High pressure over the central Atlantic will steer 94L due west or just north of due west for much of next week. (Tropical Tidbits)

What is troublesome is that the odd lack of latitude gain and the oddly far south for October placement makes this a candidate to potentially run into the Caribbean islands. And if it can find a hospitable environment to strengthen in before that point, well we may actually have a storm to watch in the Caribbean in 8 to 10 days or so. For now, any talk of 94L’s end game is speculative at best, but this will merit watching in the days ahead.

Eclipse Outlook

Alright, tomorrow around midday central time is the big event! Our annular eclipse will occur, with totality from Oregon into northern Nevada, southern Utah, New Mexico, and west-central Texas. Will the skies cooperate?

Much of Texas will have good viewing, but cloud cover looks a little more prevalent in portions of the Panhandle and Rio Grande Valley. (Weather Bell)

Per the NWS outlook, Texas looks mostly good. As you get into the Rio Grande Valley, there will be cloud cover, particularly between McAllen and Del Rio. There will likely be at least some cloud cover in Brownsville, San Antonio, and Corpus Christi. The Panhandle will also see clouds, as should southeastern New Mexico, though hopefully not a total overcast.

Some patchy cloud cover may spoil viewing a little in northern Utah, but southern Utah looks mostly good, as does northwest New Mexico. Anyone hoping to view in Monument Valley, the Grand Canyon, or southern Utah parks should be good. (Weather Bell)

Utah will have at least some cloud cover in most spots, but it does not seem like enough to obscure the eclipse, especially near the path of total annularity. Coastal Oregon looks clouded in, with gradual improvement as you head east across the state and into Nevada, which should just have patchy clouds here or there.

Coastal Oregon will probably have the sun obscured by clouds, and conditions may struggle a bit farther inland but conditions improve in Nevada. (Weather Bell)

Overall, the only two places that I think will have real problems are coastal Oregon and portions of the Rio Grande Valley. Hopefully you’re able to see it where you are if in the path, and please remember to use eye protection!

Elsewhere, we should hopefully see the beginnings of calmer weather this weekend nationally after some heavy rain of 1 to 3 inches today for Chicago, Milwaukee, Madison, and Minneapolis. An inch or two will fall tomorrow in the Mid-Atlantic as well. More for you Monday!