September is going to go down as one of the most historic months in American history, starting basically with the heat that has gripped much of the country. It was the warmest September on record for many locations. But memories will be leant to Hurricane Helene, and the victims throughout the southern Appalachians who saw their lives and livelihoods washed away.
The day to day weather doesn’t always seem extraordinary, but it does affect our every day life even outside of the headlines. It’s important to get it right everywhere, and the outlet that could claim that tile in September was The Weather Channel, who seriously clobbered the rest of the competition, securing the win in 3 out of the 7 forecasts.
8:14PM: Helene has really made an impact. The good news is that the storm made it onshore in a relatively sparsely populated area. The other good news is that the storm moved quickly, landfalling only yesterday and is now over the Ohio Valley. The bad news is, this very strong storm and it tracked over the southern Appalachians. Undoubtedly, you have heard that Asheville, North Carolina has been cut off by flash floods. Those red and purple rain totals around Tallahassee and central Georgia are much more manageable than when you get up towards the terrain of the Piedmont.
Rain will continue for another couple of days, growing weaker over the Lower Ohio Valley, but in another bit of good news, recovery can start now for those affected.
Francine is dawdling through the Lower Mississippi Valley. Last night, models suggested she might meander as far north as Minnesota and Wisconsin and I was naturally curious. I don’t recall such a feature ever reaching this far north, so I looked to confirm that was still the suspicion today. Not so much.
One thing I did notice, though, was something that appeared on both American models by Monday evening. I’ve selected the NAM because it is more dramatic looking, but it also appears on the GFS outlook for the same time.
You might find yourself getting ready to head to the grocery stores to stock your cupboards on the Outer Banks, or perhaps looking for safe haven inland. Right now, however, there is nothing even appearing on the NHC page for this zone. There are other waves, and even a Tropical Depression 7 out in the Atlantic, but this is not presently being monitored for development in the net 48 hours.
A massive reason for that is that this feature projects to develop out of thin (well, thickly humid air) air over the Gulf Stream. Certainly possible, but there aren’t obvious drivers for the development, like the induced rotation of a wave. Second, and this is very important: the American Models are the only sources pinging this development.
Moving forward, the GFS and the NAM took their low into North Carolina and Virginia, eventually wasting away in West Virginia. The Europ leaves the band of precipitation over the Atlantic, generally unchanged. Through the extended forecast, this band still remains there, adopting a bit of wave in the long term, but not at the same time or to the degree that the American output suggest.
It’s the tail of a cold front, associated with the wave moving through the Northern Plains today. We should hope for the European Model to bear out, because this would suggest TD7, even if it develops, is going to get pushed north in the open ocean. It may also suggest that the NHC observes the GFS/NAM solution, and isn’t monitoring for tropical development, instead labeling whatever potential gnarliness as subtropical.
We will need to continue to monitor the tropics over the weekend. It looks like we will be in the clear, but it is also important to realize things may change on a dime.
At long last, and now at the apex of hurricane season, there is a tropical storm in the North Atlantic. Francine emerged in the Bay of Campeche, and has started to churn through the Gulf, slipping past the Texas Coast and is now churning towards the Louisiana Coast as a category 1 storm.
Francine is approaching the shore even now, and should landfall in central Louisiana this afternoon south of Morgan City. The storm is close enough to the coast, and generally small enough that the hurricane warnings don’t even cover the entirety of the Louisiana Coast, let alone graze one of their neighbors.
Before I go on, I do want to say that for the people this storm will impact, it will still come with dangerous winds, the threat of tornadoes and flash flooding in the locally heavy bands. That said, this storm is not nearly as intimidating as other hurricanes we have come to know in recent years. The storm doesn’t have the same strength, and is expected to clear Louisiana fairly quickly.
Storm surge is possible with any storm, but the southwest to northeast fetch of any surge will cause the impacts to be mitigated. The storm isn’t strong enough, and hasn’t had enough momentum to bring a lot of water with it, but also if it was stronger, the angle it is coming at is going to push moisture into relatively low population bayous.
And while rain bands will certainly provide localized downpours, the storm is going to be moving northward and out of the area relatively quickly, so those bullseyes will be just that – bullseyes, and not regional floods for all of southern Louisiana.
Perhaps the most interesting thing about Francine is where she will be going after landfall. Right now, the best projections have her following the Mississippi northward, unsteered by an subtropical feature, and free to meander northward, I’m sure Iowa hasn’t been expecting a tropical storm this year, but it is certainly not out of the question.
As always, heed all warnings and alerts as Francine makes her way inland, but also appreciate that she may be on her way towards being a memory by the end of the weekend.
I was out of pocket quite a bit this past month, which meant I didn’t post nearly as many forecasts I would have liked. All that said, The Weather Channel was able to use this small sample size to surpass the rest of us competitors ahead of what has already been a busier month. Can they maintain the momentum? Stay tuned to find out.
The beginning of the month of August was relatively quiet in the North American weather market. There were a couple of tropical features, but they were marked by their languid movement (Debby) or hit small landmasses, away from the American shores (Ernesto). The severe season has been slowed as well. Debby was the only real tornado producer of the month to date.
This will be changing over the next several days, as is often the case as summer changes to fall. Not only should the Atlantic basin start getting moving — there are two curious looking features on the long range model guidance — but with the change in air mass coming with the change of season, there should be enough of a conflicting air mass to produce strong thunderstorms on a regular basis, at least for a few weeks.
This isn’t atypical. There is usually a secondary severe season in the autumn, though cold air is typically more forceful than warm air. As a result, the cold can more easily sweep warmer air away, while warm and cold do battle for longer in the spring. Even though the fall season is shorter, the storms can be quite powerful.
Such was the case in the Great Lakes early this week, where strong straight line winds brought damage to the Twin Cities in a couple of rounds, and then carried on through Wisconsin and eventually Michigan. Consider this the opening salvo of the Fall season.
Severe weather is much more challenging to predict at longer ranges than tropical weather, at least in terms of trends, so we don’t know exactly what to expect more than a few days out, but we do have the short range outlook, which is looking askance at the wave moving through the Dakotas today. Severe weather is possible today and tomorrow, and may carry through across the Great Lakes again as the weekend approaches. Eventually, it will work south again before winter finally seizes the scene.
Thus far, the biggest tropical story in the Continental US surrounded the remnants of Beryl after it had done it’s worst in the Caribbean, and Debby, which was more notorious for lingering in the southeast than for being particularly strong. Now, Ernesto took a swipe at Bermuda and has left us with nothing to monitor in the Atlantic Basin.
Saharan sands are blowing off of the African continent, and getting into the trade winds, inhibiting cyclonic development. The NHC foresees no tropical development for at least the next 48 hours, and the GFS – by no means meteorological gospel – doesn’t really show anything in the area until around Labor Day, nearly two weeks from today.
That’s a real slow stretch in a season that was promised to be very active, particularly since the peak of hurricane season is typically in early September. It seems like this might be a precursor for saying that the season may not be as busy as we believed at the outset, but it is not. Even with the data we have on hand, and access to the freshest short term modeling, the Hurricane Center’s latest outlook came out, and didn’t go easy on the number of tropical storms.
There will still be a week or so from the end of the GFS run to the traditional “peak” of the season. After this peak, the oceanic temperature doesn’t immediately fall off. The season begins in June, and has been creeping earlier. As a result, the season still goes another couple of months, until November. Plenty of time, and with the very warm Atlantic, plenty of fuel still left for storms.
Enjoy the last bit of summer, but remember that by Labor Day, things may be getting pretty hairy in the Caribbean once again.
Undoubtedly, in the last 10 years or so, there has been an increase in hurricane headlines. Part of this is because of our own unconscious bias. The US went for about a decade without a landfalling hurricane, which is pretty much absurd, and now that the rate of American landfall is ticking up, it feels like it is happening all the time.
And of course, with alarm bells ringing on the increasing heat in the ocean, we are acutely aware that the hurricane season is longer than it ever used to be. Sure, there are more large hurricanes making landfall in the US recently, and the season has become longer over the last couple of decades, but this doesn’t fully translate the issue.
As I said, we had a long lull after Katrina, where the US was spared, so an uptick in landfalling storms was always going to seem worse than it had been in recent memory, even if it is more a correction to what is a normal landfall rate. I think the misperception, however, is that we are having a bunch of strong storms regularly arriving on US Shores, when that is not really the case.
One thing is true about tropical storms is that they are being infused with more moisture, and as a result are bringing more rain. Every storm you see now has a greater tendency to produce flash flooding. This is partly being seen in Debby, where parts of the Carolinas and Georgia have been inundated. Debby wasn’t a particularly strong storm, but she was sure a soaker.
This is where the longer season comes into play a bit. As we know, the transition seasons of spring and fall tend to have the most dramatic weather over the continental United States. The jet dives south and brings active cold and warm fronts that make life a bit more interesting for everyone. Historically, the hurricane season is most active in September, just when things get more interesting with subtropical weather, and these cold fronts usher remnant hurricanes off into the north Atlantic.
In August, the dog days of summer, there are no big jet troughs or cold fronts, and storms are left to dawdle. Debby has been such a danger because she’s not been forced offshore. Harvey was an August storm, and he had the same issue 7 years ago. Dawdling. Storms are carrying more moisture, and early season storms especially are less likely to be kept moving, and flash flooding is on the rise with tropical storms. Expect this trend to continue for the long term.
July was a month heavy on Bloomingtons, but was fortunately not as robust in weather headlines as we have come to expect in the summer. Sure, we’ve certainly had some heat, rain, storms and everything that comes along with the summer, but it wasn’t quite as horrific as the last few years. Baby steps. The Weather Channel took the crown in the first month of the second half of the year.
Finally, the Western US was inundated with a drought quenching rain throughout the winter and into the spring. It was a profound relief for a part of the world that had a drought for so long, and endured a threat for fires every summer for years, and a relief for cynical newscasters who didn’t want viewers to think they were watching reruns every year.
And yet here we are again, buffeted by wild fire stories. Granted, they aren’t as widespread, either the fires or the stories, but they are cropping up again. The stories aren’t as prevalent because the threat to life and property hasn’t been as immediate, and the fires aren’t quite as encompassing because the environment is a bit less dry than it’s been in years.
But even in the best years, fires are always possible out west. Just because the winter was wet doesn’t mean that holds for the summer. There is ground water, but it’s always dry in the summer out west. One thing that compounds the threat is that it’s also extremely warm. The heat helps to dry things out and create more fuel to the fires.
Additionally, we are in the midst of the monsoon season in the intermountain west. While we associate the word monsoon with the inundating rains of south Asia, in the western US, it means widespread thunderstorms, but those storms may not necessarily come with rain. Lightning with these storms has historically been the natural cause of wildfires, and it is in full force again this summer.
The dog days are here. and even though some relief is coming for the coast, the Rockies will stay hot, dry and favorable for thunderstorms and wildfires.
