The autumn is scary season for more reason than one reason. Milton followed Helene in September, battering the west coast of Florida, a drought in the Plains coming to an end, and the first snow of the year in the Mountains and northern Plains. After what has been a pretty scary year for Accuweather forecasters, they can finally point to October as a solid month, and one in which they were victorious.
A lot of the attention for the last month has rightfully been on the southeast where two major hurricanes, Helene and Milton devastated areas from western Virginia to south Florida. Surge and wind were major problems, as always, but this hurricane season is going to be forever remembered for all the rain that fell, and the flooding that ensued.
It seems like I am talking about a different planet, then, when I reference the lack of rain in the middle of the country. But indeed, it is the middle of the same country that has not seen rain for weeks. Minneapolis is working on a top three dry spell, measured by the length of time since their last recorded rainfall. Southern Minnesota and all of South Dakota haven’t seen a drop of rain in a month.
There hasn’t been much rain anywhere in the Plains, which is particularly jarring because this area is adjacent to the part of the country that saw so much. Fortunately, a lot of this area was well hydrated earlier this year, and drought hasn’t yet seized the area in a particularly consequential way.
We are getting deeper into autumn, and by the middle of next week, it will start snowing across the northern tier, including the dry part of the northern Plains. It can’t come soon enough.
Springfield, when we visited at the beginning of the month, was in the midst of a spate of high pressure that kept things pretty dry, and pretty stable. Victoria-Weather followed along with the model guidance, which is pretty reliable when compiling temperature forecasts in a static airmass. We ended up with the top forecast, but really, it should have been much closer. Instead, multiple outlets were 10+ degrees behind us in their score. This was such a straightforward forecast, I thought, so I can’t even tell you what went awry! Actuals: October 7th, High 70, Low 41 October 8th, High 74, Low 38
9:39PM: This is a pretty incredible look at the before and after of Helene, from space. (First seen at NPR)
Satellite images from the #VIIRS Day-Night band onboard the #NOAA20 satellite reveal Hurricane #Helene's impact.
Before and after images from Sept. 25 and 28, 2024, highlight power outages in parts of Florida, Georgia, and both South and North Carolina. pic.twitter.com/9m2J6y2RMJ
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.
