Matt Lanza

Winter about to come roaring into the Great Lakes, Midwest, and Northeast

Headlines

  • Major Thanksgiving Day/Friday storm possible in the Eastern U.S., with snow possible in the interior or Ontario.
  • Cold air mass follows into the weekend.
  • Surge of mid-winter cold follows next Sunday into the first week of December, primarily for the Midwest, Great Lakes, and Northeast.

With hurricane season now behind us, it’s time to talk about winter. And if you live in the eastern two-thirds of the country, you’re going to see a pretty impressive dose of it incoming after Thanksgiving.

Active weather to kick off the week

The weather map today shows a continued pattern allowing for moisture in the West with several feet of snow coming to the Sierra Nevada. A major warm up is going to occur in the South-Central U.S., while colder air exits the Northeast.

An active weather pattern will deliver heavy snow to California and a major warm up in Texas (Tropical Tidbits)

In fact, Monday will see record highs possible across southeastern Texas, including for Austin, San Antonio, and Houston, as well into Shreveport. Most of these records were set back in 1967, which would have been late in that year’s Thanksgiving weekend.

Record or near-record highs are forecast on Monday in Texas. (NOAA)

The snow forecast in California will be in feet, and “extreme” winter weather conditions are expected in the Sierra. As much as 7 feet of snow may fall at the highest elevations, giving California a big jump start on their water year snowpack.

Extreme impacts from snow are expected in the high Sierra. (Pivotal Weather)

First wave of cold

One cold front will sweep across the country Wednesday and Thursday, ushering in cooler temperatures on Thanksgiving Day and Black Friday.

Friday’s forecast temperature departures from normal, shows widespread colder than normal conditions everywhere except the Desert Southwest, Maine, and South Florida. (Tropical Tidbits)

The first wave of cold is likely to come with a winter storm in the Eastern US, followed by lake effect snow as well. There is a great deal of uncertainty as to where heavier snow may fall on Thanksgiving Day and Friday, but portions of Ontario, interior northern New England, and Upstate New York would be firmly in the potential.

Extremely uncertain and wide-ranging forecast spread in possible positions of low pressure center on Thanksgiving Day and Friday leads to high uncertainty on snow placement. (Tomer Burg)

But for a 5-day out forecast, this is a really significant spread in possibilities. A track toward the Mid-Atlantic would keep the heavier snow firmly in place for portions of New York and perhaps Pennsylvania too. A track over Upstate New York would probably push the heavier snow back into Ontario. Either way, Thanksgiving Day travel in the Northeast and eastern Great Lakes will likely be impeded by this system. Start planning now.

Second wave of cold; the real deal

For those looking for winter air, you will get your wish after Friday or Saturday. A second surge of cold air, almost direct from Siberia is going to plunge into the Great Lakes and Midwest. This will usher in the coldest air since last winter, along with all the stuff that comes with it: Biting wind chills, potential for major lake effect snow, and at least a chance of additional snows here or there. For folks in Texas, it will turn colder but not nearly to the levels we’ve seen at times the last few winters. This cold is primarily directed into the Midwest and Northeast.

Coldest air since last winter plunges into the Midwest, Great Lakes, and Northeast late in the holiday weekend and during the week after. (Tropical Tidbits)

What does this translate to? We’re likely talking about highs in the 20s in Chicago and lows in the single digits or low teens. Similar temperatures would occur elsewhere in the Great Lakes and Midwest, so places like Cleveland, Detroit, Indy, and Minneapolis would all experience mid-winter type cold. Bottom line? Winter is coming.

Beyond that, December will probably see a bit of a warm-up after the first week, but it may take some time to dislodge the cold. Either way, November is going to go out with a bang across the Eastern U.S.

Hurricane season appears to be unofficially over, so let’s do a quick review and talk about bomb cyclones in the West

Headlines

  • Hurricane season is unofficially over, as no activity is seen over the next 10 days, taking us through to about December.
  • 2024 will end up as a “hyperactive” season but barely.
  • Meanwhile, the West is seeing a storm almost as strong as a major hurricane spinning offshore.
  • Significant, damaging wind is possible in the Seattle area tonight.
  • A prolonged atmospheric river in California and southern Oregon will produce over 10 inches of rain in spots, and a rare day 3 high risk (level 4/4) of flooding exists in northern California for Thursday.

2024 Atlantic hurricane season ends — we think

With the degeneration of Sara’s remnants yesterday, it would appear that we’re basically done with the 2024 Atlantic hurricane season.

Exhale. (NOAA/NHC)

Unfortunately, Tropical Storm Sara was deadly in Honduras while dumping upwards of 20″ or more of rainfall. As much as 1,000 mm (40 inches) was analyzed in northern, coastal Honduras. Though deadly, it appears that the number of fatalities will remain well under some other notable rainstorms of the past in Central America. Good warnings likely helped.

With that, the season seems to be over now, as we see nothing over the next 7 days, and the models are pretty quiet beyond that. So where will we finish? It appears 2024’s accumulated cyclone energy (ACE) will finish at the bottom of the list of hyperactive seasons. We had 18 storms, 11 hurricanes, and 5 major hurricanes. The 11 hurricanes tie for fifth most in a season.

This season’s accumulated cyclone energy (ACE) was driven by a late season surge, just pushing us to the edge of “hyperactive” status for the year, impressive but perhaps less so given the seasonal expectations. (Colorado State)

Did the season live up to the preseason hype? Probably not. But with over $190 billion in unofficial damages, it ranks near the top of the list of worst seasons on record. So you can find a metric that says this year was as bad as feared or was a total bust. The world is your oyster. But for parts of the Caribbean, Florida, and Appalachia, this season will be for the history books. And that’s really all that matters.

We can take a more in depth look at the season later. I want to transition us into post-season mode now at The Eyewall. We’re still experimenting with what works because we want to continue to grow our audience, but we also want to stay in our lane to an extent. Ultimately though, weather is our lane. And we should be chiming in when significant weather is a big story. And today, it’s a big story on the West Coast.

Western U.S. and Canada drenched and pummeled

There are two major stories developing on the West Coast. The first is occurring as I type this. A massive storm is rapidly deepening off the Northwest coast.

A massive, potentially historic storm has developed off the coast of Washington and Oregon. (Weathernerds.org)

Yes, this is a bomb cyclone. That term gets tossed around often, and some people consider it hype. But it’s a legitimate meteorological term with a very specific definition. The lowest pressure of the storm must drop at least 24 millibars in 24 hours or less to attain “bomb cyclone” classification. While it may seem like bomb cyclones are rare, they really aren’t, happening multiple times a year on average near North America. What makes this particular storm stand out is the amplitude and rate of deepening that it is undergoing. Basically, the storm has dropped over 25 millibars just this afternoon, achieving “bomb” status incredibly quickly.

There will be multiple impacts associated with this storm, including a major downslope wind event east of Seattle tonight, where gusts in excess of 50 to 60 mph could occur in some of the heavily populated suburbs near the Cascade foothills. This will be worse than a typical wind event for this region, likely causing some localized damage and numerous power outages.

Very strong downslope winds in the Cascade foothills tonight could cause damage and knock out power on the eastern side of the Seattle metro. (NWS Seattle)

In addition, strong winds will occur at the coast, though thankfully the worst winds will remain well offshore due to the storm not making landfall. Heavy mountain snow and lower elevation rain will occur as well, and blizzard warnings are posted for the Cascades.

Meanwhile, a long duration atmospheric river event is going to take aim at California and southern Oregon in the coming several days, dumping copious amounts of rain and mountain snow, and some rain-on-snow potentially as well.

Over the next 3 days, the strongest portion of the atmospheric river will aim at northern California. (Scripps Center for Western Weather and Water Extremes)

This will peak as a category 5 atmospheric river, which means significant impacts are likely, and the NWS Weather Prediction Center already issued a high risk of flooding (level 4/4) for northern California on Thursday, which I believe is the first time this has occurred for a non-tropical storm.

A high risk (level 4/4) is posted for northern California , north of Mendocino for Thursday for flooding rain. (NWS WPC)

High risks don’t seem to be as rare as they used to be, but obviously for a day 3, confidence has to be exceptionally high or the risk has to be exceptionally high. I think a confluence of factors is impacting that. In terms of rainfall over the next week, it’s going to get messy. Over 10 inches of rain should fall in some of the mountains in northern California. Snow will also occur, but as the atmosphere warms a bit, the snow levels will increase. So this could be a damaging event in addition to a possibly beneficial one. Extremes rule the day in California. More to come.

Tropical Storm Sara near the Honduras coast, a Central America flood maker

Headlines

  • Catastrophic flooding from Sara is possible in northwest Honduras.
  • Significant flooding and mudslide risk exists elsewhere, from the southeastern Yucatan into Belize and in portions of Nicaragua.
  • Sara is very close to the coast of Honduras now and should generally maintain intensity with just a little strengthening once back out over water en route to Belize Sunday.
  • Sara’s remnants will be absorbed into a Gulf of Mexico cold front next week with no direct impacts to the U.S. expected.
Tropical Storm Sara made landfall in Honduras and will drift toward Belize this weekend. (NOAA NHC)

Tropical Storm Sara dumping rainfall on Honduras

We’ve been discussing Sara all week, and the one element we keep trying to hammer home is the flooding threat this storm provides for Honduras in particular but now also Belize.

Catastrophic flooding is possible in northwest Honduras with severe flooding elsewhere into Belize and perhaps even the Yucatan as Sara drifts that way. (NOAA WPC)

The mountainous portions of northwest Honduras are likely to see the worst of the flooding. Rain totals may exceed 20 to 25 inches in this area (500 to 600 mm). Outside of that, rain totals north of 10 inches are likely from Quintana Roo into Belize, the central coast of Honduras, and perhaps into portions of Nicaragua. These types of storms typically end poorly in these areas, so all we can do at this point is hope for the best.

In terms of the tropical element of things, the National Hurricane Center noted this morning that there is a distinct lack of observations available from Honduras, so trying to pin down the center of the storm has been challenging. But using satellite, we can see where the heaviest thunderstorms are at least.

Tropical Storm Sara is somewhere near the coast or just inland in Honduras with very heavy thunderstorms occurring in western Honduras and just off the coast of Mexico and Belize. (Weathernerds.org)

And indeed those heavy storms are hammering portions of western Honduras. Sara will likely hold steady or weaken just a bit depending on if it’s over land or over water. All in all, we don’t expect a whole lot of major change in Sara’s intensity over the next couple days. Sara will have a little runway to perhaps work with on the way from Honduras into Belize as it passes over the Caribbean again. But the ceiling for intensity should remain fairly low, as it will quickly move back over land in Belize and the Yucatan. Its time over land there should essentially kill it off before it gets absorbed into a cold front over the Gulf of Mexico next week.

Beyond Central America, no direct impacts are expected in the U.S. There is some chance that as Sara is absorbed into next week’s cold front it could help enhance rainfall or introduce a severe weather risk to Florida, Georgia, or the Carolinas. But that should be all.

Never say never, of course, but beyond Sara, we think that’s probably it for the 2024 Atlantic hurricane season. We’ll have more to come on Sara this weekend.

Tropical Depression 19 will be a deeply serious flooding threat for Honduras

Headlines

  • Tropical Depression 19 should become Sara later today.
  • Sara will be a deeply serious flooding threat to coastal Honduras.
  • The odds of a major hurricane, in particular a major hurricane tracking toward Florida have dropped off since yesterday.
  • There is still substantial uncertainty surrounding the details of Sara’s development and peak intensity, but broadly a drift/stall near the coast of Honduras through the weekend, followed by a track toward Belize and the Yucatan and then a hook northeast toward Florida is favored.
  • Also, our parent site, Space City Weather is doing our annual fundraiser if you are interested in also directly support the work of The Eyewall!

Quick sidebar: Over at our primary site for Houston, Space City Weather, we launched our annual November fundraiser yesterday. Basically, for now, it’s the one chance you have to monetarily support our work. If you don’t have extra money, please do not feel pressure to give; your using the site and spreading the word helps just as well! Ultimately, it does cost a lot to operate a website; develop, update, and support an app (something we may eventually do with The Eyewall in time); and pay for all of our other activities. So if you can help, we’d greatly appreciate it. You’re ensuring our work is freely available to all. We are grateful for any support you’re willing to provide. Thank you!

On with the show…

TD 19 is going to hug the coast of Honduras over the next few days, but exactly where that stall happens is critical in determining if it becomes a hurricane or not. Either way, it’s going to deliver a massive flooding threat to Honduras. (NOAA NHC)

Tropical Depression 19: A major Honduras flood threat, less of a Florida hurricane threat

Invest 99L was given the potential tropical cyclone treatment yesterday. It’s now officially Tropical Depression 19, and it is expected to become Sara by later today. The track of 19 is pretty straightforward — but also immensely important and sensitive to exactly where it sets up. If we look at the forecast for hour 60, which is for Saturday morning, notice that the models are in pretty solid agreement. Each dot below shows where one of the 51 ensemble members is placing Sara’s center at that time.

There is good model agreement on roughly where Sara will be over the next 3 to 4 days. But the proximity to land is going to throw an enormous wrench into determining the exact intensity. (Tomer Burg)

For Honduras, unfortunately this only means the difference between a really bad situation and a really, really bad situation. Significant flash flooding and mudslides courtesy of torrential rain will be likely heading into the next several days as 19/Sara crawls along the coast of Honduras.

Rain totals could exceed 20 inches (500 mm) in parts of coastal Honduras over the next 5 to 6 days, leading to severe flooding. (NOAA WPC)

If the center of Sara stays offshore, it could become a hurricane, which would yield an even worse outcome. But even if that does not happen and Sara stays along the coast or just inland, the rain issues will be just as bad.

But that position of Sara over the next 3 or 4 days will have implications on what happens next for Belize, the Yucatan, and Florida. Sara should eventually get dislodged from its stall and start tracking toward Belize and the Yucatan by Monday. Obviously if it’s still over water and a hurricane, that could produce a pretty rough impact on Belize or Mexico. If it emerges from over the physical coast of Honduras, it will be less of a threat to be a hurricane.

Models have increased agreement on land interaction with Honduras keeping the storm weaker and more over land the next 5 days, but there is still uncertainty. (Tomer Burg)

If anything, trends since yesterday have drastically lowered the potential for a hurricane or major hurricane. There is simply too much land interaction with Honduras and the Yucatan or Belize. But there is a heaping amount of uncertainty still.

For Florida, this means that the threat of a significant hurricane on the west coast seems to have fallen off a good bit since yesterday. That’s good. I would continue to monitor this closely, but the trends have been friendly to you. There could still be some heavy rain and strong thunderstorms as a powerful cold front sweeps across the state next Wednesday. We’ll assess this in the coming days.

In the meantime, any interests in Honduras in particular, but also perhaps Belize or the Yucatan should monitor Sara closely. Even if it never becomes a hurricane, the flooding threat is dire for coastal Honduras. We’ll keep following this aspect of things.