In brief: A moderate risk (3/4) remains posted today for flooding between Washington, DC and northern New Jersey with isolated 4-to-7-inch totals expected. The tropics remain quiet, and heading into the first half of August, it’s not apparent that things are going to dramatically increase. We’ll keep watching.
Fairly brief update today, but let’s get to it.
Flooding risk in the Mid-Atlantic
There continues to be a moderate risk (3/4) of flooding today in the Mid-Atlantic region.
A moderate risk for excessive rainfall exists from just south of DC to just west of New York. (NOAA WPC)
Modeling continues to strongly suggest the potential for isolated pockets of 4 to 5 inches or more of rainfall across the moderate risk area. Potential does exist for perhaps up to 7 inches of rain in some really isolated spots. Many areas will be fine today, but the entire region is at risk for something a little more serious, hence the moderate risk.
HREF model probability-matched mean rainfall forecast for Thursday showing pockets of high rainfall. (NOAA SPC)
Basically, it’s a good day to make sure that you plan around the rain in the region. Maybe hang tight at your location for a bit if it’s raining heavily. Have a way to receive flash flood warnings. And do your best to never drive through a flooded road, as the water is often deeper than you realize.
Tomorrow’s rainfall risk shifts southward into the Southeast, mainly the Carolinas.
A slight risk (2/4) of heavy rainfall and flooding exists in the Carolinas for Friday. (NOAA WPC)
That risk will probably hold steady in that area for Saturday as well.
Tropics still mostly benign
Another day with no tropical threats on the map from the National Hurricane Center today. As all the thunderstorms in the Southeast begin to push offshore, there is a very, very slight risk that something may try to briefly spin up and head out to sea from there. But those odds look quite low.
Overall, the Basin looks about average for this time of year right now. Over the next couple weeks, I’m not convinced it’s going to get more favorable. Of course, given that climatology begins to ramp up in August, that should still mean we see something at some point in the next 2 to 3 weeks. That’s just a given. But in terms of getting a lot of activity, significant activity, etc., I’m not sure I see the background state of the Atlantic cooperating in a significant way right now.
If you want to look out far in time, we can grab the European model’s subseasonal outlook for tropical storms.
The odds of a tropical storm per the Euro weeklies yesterday is highest off the East Coast in mid-August. (ECMWF)
The odds of a tropical storm in mid-August (we’re looking at the week of August 11th here) aren’t exactly strong. Some European model data suggests perhaps something could emerge off the Eastern Seaboard, but the odds at this point remain below 30 percent, or close to normal for this time of year. Conditions may become a smidge more favorable by later August, but again, that should be expected in a normal hurricane season.
In brief: An upgrade to a moderate risk of flash flooding was triggered for Thursday in the Mid-Atlantic, including DC, Baltimore, Philly, and much of Jersey. The tropics remain quiet, but heavy rain is likely to pester the Southeast heading into next week.
For the latest on the tsunami and major earthquake last night, I’m going to point you elsewhere. There are plenty of good seismologists and geologists out there that can explain much of what happened better than this meteorologist. A number are active on various social media platforms, good people to seek out to understand this stuff. Meteorologists are often the ones used to explain various earth and astronomical events, often because we’re just generally decent science communicators. But there are so many others out there that are better at those events than us. You don’t want an astronomer explaining molecular biology to you, so no difference here.
Mid-Atlantic flooding risk Thursday
I want to start our weather discussion this afternoon with some updated news. The Weather Prediction Center has upgraded tomorrow’s flash flooding risk in the Mid-Atlantic from slight (2/4) to moderate (3/4). Data today has come in pretty aggressive with potential rainfall tomorrow between northern New Jersey and northern Virginia.
(NOAA WPC)
This risk area includes Washington, DC, Baltimore, Philly, and most of the I-95 corridor southwest of New York City. Per the WPC discussion, with the area lying sort of close to a couple key meteorologically supportive areas for heavy rainfall, this sets the stage for impressive rain totals, some training thunderstorms (storms that repeatedly travel over the same locations), and an urban area that is naturally prone to flash flooding. Flood watches have been issued today for Thursday’s storms.
Looking at model data, it’s pretty clear that while the entire region will see some rain, the biggest concerns will be in isolated pockets between northern Virginia and northwest New Jersey.
The SPC’s HREF model shows a signal for isolated pockets of 5″ or more of rain on Thursday in parts of the Mid-Atlantic. (NOAA SPC)
The HREF model shown above which is an ensemble of a few high-resolution models produces a product called the probability-matched mean, which tends to flag areas of higher risk and what those totals could be. And indeed on this morning’s run, it shows legitimate potential for 5 inches or more in pockets around DC and Baltimore, as well as near and north of Philly. Exactly where those higher totals establish is very much up in the air this far out. But this is why the moderate risk covers a broad area in parts of the Northeast Corridor. Even in areas under the lesser slight risk (2/4) should take heed that heavy rain is possible, if not likely tomorrow, including southern New England and parts of New York State south of Albany and into the Catskills.
Bottom line: Flooding potential is very elevated tomorrow in the Mid-Atlantic, so stay on your toes and be alert.
Tropics remain calm
All remains quiet in the Atlantic with no highlighted areas anywhere in the Basin for the next week. We continue to see “noise” on the modeling off the Southeast coast next week, but any system would likely pull east out to sea. Nothing to home in on beyond that right now.
We will see heavy rain as a result of the pattern setup along the Southeast coast. This is probably why the models are latching onto some sort of low-end potential in that region next week. Anyway, the rain will bring probably 3 to 5 inches of liquid to much of the Southeast or southern Mid-Atlantic.
Heavy rains are likely over the coming days in the Southeast and near the coast, perhaps to the tune of 3 to 5 inches or more. (Pivotal Weather)
The heaviest rains look to be on the Carolina coast with 4 to 6 inches possible from the Outer Banks south to Savannah.
In brief: The tropics are busier but lack teeth right now in the Atlantic. A critical hurricane forecasting and observation tool received a permanent stay of execution today. And perhaps there is a sign of a reduced pace of significant weather across the country as August begins.
Tropical Atlantic amuse-bouche
We continue with a quiet tropics today with no immediate or credible threats of note across the Atlantic.
(NOAA NHC)
We’ve got a rather beefy tropical wave off the west coast of Africa today, but it’s not organized, nor is it expected to really organize over the next few days.
Tropical Atlantic wave train is beginning to crank up, although none of these areas are expected to develop. (College of DuPage)
We’ve also got a wave over the central Atlantic, again, not expected to organize. There’s a really solid area of thunderstorms in the western Caribbean, but that will soon move over land.
We continue to see signs, hints, possibilities, etc. that we’ll end up with some action off the Southeast coast in about 5 to 7 days, but I think because there’s not any real consistency to this or any real sign of significant possible development that we don’t see any risks drawn today.
The European ensemble model shows numerous members with some sort of low pressure signal off the Southeast coast in about a week, but there’s not much else “there” there just yet. (Weathernerds.org)
So for now, we will just watch and see if anything can get going, but at this rate, it still feels very much like the amuse-bouche to an active period more than the start of an active period itself.
Hurricane tools get a stay of execution
We received some good news today. Per NOAA, the SSMIS microwave satellite imagery that has been a bone of contention over the last couple months, threatened to be pulled due to cybersecurity risks was given a permanent stay of execution today.
NOAA statement on the continuation of DSMP data. (NOAA)
Why does this matter? The SSMIS data is far and away the best data available for understanding and validating traditional satellite imagery when it comes to monitoring tropical systems. It provides added lead time on rapid intensification episodes and allows for better estimates of initial positions of these systems, which is an absolutely critical input to weather models for prediction of future track and intensity. Without this data, we would have been in a not so good place, pending a suitable replacement.
There are a few ways to look at this. First, this is not a victory. Let’s be blunt about this: For the last 7 months, NOAA and the NWS have been governed by seat-of-the-pants decision-making by the Commerce Department and the Trump Administration. It’s been pure chaos. This isn’t a partisan statement; it reflects the reality on the ground. If this were a business, the CEO would have been run out of town by now. (Now, that may be a partisan statement to some extent) It’s no way to run the premier weather science agency on the planet, and it’s been a disgrace to watch, truthfully. People were fired, then they weren’t, then they were. We had satellite data, then we didn’t, now we do again. There was a hiring freeze, and now there isn’t one. The Administration wants to gut funding to NOAA research, critical weather and climate research, and Congress has told them no. It takes forever for the Commerce Department to sign off on almost any expenditures which has led to data lapses. This doesn’t even factor in the absurd handling of FEMA so far this year. The chaos is unsustainable, and it needs to stop. The public servants at NOAA deserve better, and so do the American people.
Second, this is also an issue that NOAA should have probably identified and rectified by now. These satellites run by the Department of Defense are 15 years past their 5-year design life. That’s a long time. We probably should have had a viable alternative in the skies already. Hindsight is 20/20, of course, right? It’s easy to sit here and say coulda, woulda, shoulda. And it’s even easier to get funding for these things, right? No, of course not. But the reality is that if something has a design life of 5 years and it’s on year 20, you probably are on borrowed time. Maybe in year 10 or 15 it would have been wise to get the ball rolling on this stuff for replacement. But here we are.
Last, it does ultimately beg the question of why the decision was made a.) so abruptly to terminate the data (DoD gave literally just a few days’ notice back in June the first time), and b.) to rescind that decision if there is a valid cybersecurity risk? Was the risk not that serious? Is this a basic cost-benefit situation where the risk of losing the weather data operationally is greater than the cybersecurity risk? I don’t know if we’ll ever know, but it certainly doesn’t reflect well on the “most transparent administration in history.”
A calmer period?
Last, let’s close with (hopefully) some good news. I believe today is the 38th day in a row with at least a slight risk (2/4) of excessive rainfall and flooding risks somewhere in the Continental United States.
Slight risks for excessive rainfall and flooding in New Mexico and the Plains today. (NOAA WPC)
That’s a painfully impressive streak. I don’t think it’s yet the record, but it’s been rough. We’ve got 4 more days of this ahead of us at least. We’re not into quieter weather yet. Flooding risks will continue. Heat will continue. But ultimately, we will see quieter weather emerge. In fact, the day 3 to 7 outlook for hazardous weather is slowly losing areas of interest and coverage.
Day 3 to 7 weather hazards include some additional heavy rain and heat risk, but a gradually less widespread coverage of significant weather. (NOAA WPC)
Quieter weather doesn’t necessarily mean quiet weather. But hopefully things will calm to a pace that is slightly more manageable.
In brief: Tampa reached an all-time high temperature record yesterday. The Atlantic tropics, while busier, still lack a lot of organized risks. And a destructive wind event is possible later today and tonight, primarily in South Dakota and Minnesota.
Torching Tampa
We start today in Tampa, where it hit 100 degrees on Sunday. While that may seem like a relatively pedestrian number, it happens to be the hottest temperature recorded in that city since records began in the 1890s.
(NWS Tampa Bay)
Even 99 degrees has only been reached two times, the 2020 instance noted above and back on June 5, 1985. Notably, only four of the 25 hottest days on record in Tampa have occurred in July or August. Typically, you have a sea breeze or thunderstorms or humidity that’s too high to allow for such heat. Yesterday, the area was under the influence of an abnormally strong ridge of high pressure over the Gulf, as well as a very abnormal offshore directed wind at the time of peak heating. The combination allowed for temperatures to surge at a time of relatively low humidity. It’s a very localized nuance, but we’d be lying if we didn’t also note that it’s certainly symptomatic of a warming Gulf as well.
Gulf sea surface temperatures are quite strong near Tampa and near Port Arthur, TX, as well as near coastal Mexico. (Tropical Tidbits)
Tampa has set or tied 107 record highs and 150 record warm low temperatures since 2020. That’s not a typo. Their records go back to 1890 and 30 to 40 percent of their warm records have been met in less than 6 years. That’s remarkable.
The forecast high today is a more tolerable 97° for Tampa.
A slightly busier Atlantic
Taking a snapshot of the Atlantic basin this morning, it looks a bit more interesting than we’ve seen lately. First, we have a pretty healthy-looking area of thunderstorms north of the Caribbean islands. This is associated with a tropical wave in the area. There is very, very little model support for anything here, despite how it looks this morning. High pressure should serve to inhibit any sort of organization.
The Atlantic is busier than it has been, but it’s not likely to produce anything notable this week. (Weathernerds.org)
Secondly, we have the tropical wave that we discussed a bit last week that’s now emerging off Africa. This one still has a puncher’s chance of doing something as it comes westward through the week. Will it actually get anywhere? I don’t know; model support has continuously slipped for this one since last week. At least through Friday, en-route to the islands, there should be a very minimal chance of development.
After Friday, the picture gets a little more complex. Some modeling lifts this area more to the northwest at the same time that thunderstorms roll off the Southeast coast. The result? Something. If you look at the different ensembles, both from AI-derived models and traditional physics-based models, you see a sloppy mess off the Southeast coast in about 8 days.
Google Weather Lab’s plot of various European and AI-based ensemble members shows a signal for something off the Southeast coast next week, with an out to sea outcome favored right now. (Google Weather Lab)
I really like Google’s tool here because it gives you a good initial overview of what is percolating. Looking into this further from other models, I get the sense that there’s a signal here, but exactly what that signal is (some hybrid subtropical sloppy system, a more formal tropical entity, or something else) remains to be seen. Also, it seems that support right now favors an out to sea outcome ultimately, but again, we’re 8 days out from something that hasn’t formed yet. But I think we pretty clearly have our next area to watch, even if it isn’t a terribly serious concern.
You may have noticed on the Google plot above action in the Pacific. Indeed, it is busy out there now, with Tropical Storm Iona (expected to become a hurricane south of Hawaii) and 3 other areas to watch.
Tropical Storm Iona will pass well south of Hawaii as a hurricane this week. (NOAA NHC)
No impacts for Hawaii are expected at this time.
South Dakota & Minnesota with potent severe weather risk today
Flash flooding impacted the Reno area yesterday evening. Severe storms with heavy rain ripped across Minnesota yesterday, with rain totals of 4 to 8 inches in parts of southwest Minnesota. Eastern South Dakota was also smacked by heavy rainfall and a tornado near Watertown.
Rain totals north of 6 inches occurred in portions of southwest Minnesota and just south of Watertown, South Dakota yesterday. (NOAA MRMS)
The focus today is less on flooding and more on severe weather. There’s a fairly strong signal for a powerful line of thunderstorms to develop in the Dakotas later and rocket eastward across South Dakota and into Minnesota. The Storm Prediction Center is already qualifying this setup as a “derecho is likely.” A moderate risk (4/5) has been issued for portions of South Dakota and Minnesota. For those new to derecho, it is a long-lived area of thunderstorms that produces significant wind damage over hundreds of miles.
High-end wind damage is possible, if not likely across much of South Dakota later today, extending into Minnesota tonight. (NOAA SPC)
Storms should develop through the day in western North and South Dakota. As they come east later this afternoon and this evening, they will likely intensify into significant wind producers, along with isolated tornadoes. The highest-end risk for destructive winds appears to be from eastern South Dakota into southwest Minnesota. However, it is possible that these storms will hold together and bring significant wind damage concerns to eastern Minnesota too, including the Twin Cities later tonight. Storms should finally begin to weaken once in Wisconsin.
Bottom line: A destructive wind event is a good possibility tonight in a good chunk of South Dakota and southern Minnesota, possibly extending into northern Iowa.
