TC/EQ Update Tue 22 June

The US NHC has stopped advisories on Claudette as it no longer has a closed circulation (one of the requirements to be a tropical cyclone). The remains will continue to the northeast just off the coast of Nova Scotia and Vinland (Newfoundland) today, producing gusty winds and rain but shouldn’t be dangerous with some common sense. Elsewhere, it’s tropical wave season, and NHC is tracking one approaching the Caribbean but it only has a low (30%) chance of development over the next five days. There is a better chance for a system off the west coast of Mexico (70%). In the West Pacific Tropical Depression Six is expected to strengthen into a Typhoon and pass well east of Japan.

NHC/TPC Tropical Analysis, Tuesday Morning 22 June. Click to embiggen …

There was a fairly strong and shallow earthquake just of the coast of Asia Minor, near the Greek islands of Tilos and Nisyros, 70km northwest of Rhodes. No reports of damage yet but I would expect there to be some minor damage.

Claudette, Dolores Updates

Tropical Storm Claudette is a Tropical Storm again, strengthening as it exits the North Carolina coast this morning with gusty winds and rain. It caused only scattered damage across the Southeast, but sadly a number of fatalities in road accidents, and two caused by a falling tree. Here is the damage swath (past and forecast) based on the Monday morning forecast:

Although the official forecast track ends at 36 hours, the storm will bring gusty conditions to the Canadian Maritime Provinces mid-week as an extratropical storm.

I haven’t mentioned Dolores in the last couple of days, since I was selfishly concerned with being on the fringes of Claudette, but that storm made landfall in Mexico bringing some flash flooding, power outages, and mudslides to western Mexico inland from Puerto Vallarta. Elsewhere, there is a weak storm in the West Pacific, the long range (and unreliable) models have some stuff, but that’s it for the moment.

Tropical Depression Claudette (Sunday Update)

Claudette is now moving into North Goergia, on its way to the Carolinas and offshore. Here’s the 7am radar and GFS model overlay to give you an idea of the structure of the storm …

Radar and GFS winds at about 5000 feet

The latest forecast shows it hanging together and starting to strengthen later today before it moves offshore. That’s not terribly unusual for this kind of storm, since it can draw on warm moist air from both the Gulf of Mexico and Atlantic (look at the wind barbs in the above map). Here’s the impact swath using my TAOS/TC model driven by the official forecast:

Swath o’ doom. Click to embiggen any graphic

For the Georgia/SC Coast, that blob of rain currently over North Florida will be moving up our way in the wake of Claudette, and the forecast is for rain chances to increase and conditions deteriorate during the day. Winds are already picking up, and should be at their worst in the early afternoon (4-5pm), with rain chances and rates highest between 7pm and midnight. There is a flash flood watch up for Savannah, Hilton Head, and Beaufort (but not south of Fort Stewart at the moment). As for tornadoes (thanks Savannah Morning news for the fear-mongering scare piece on the front page today), expect a tornado watch later today as there is enough rotation and low level shear from Claudette and its interactions with the surrounding systems to spawn tornadoes, but the biggest potential threat is from gusty winds in rain bands breaking tree limbs, etc. In short, a blustery, rainy Pentecost Sunday (in the Orthodox Churches), so keep your weather radio close just in case.

#Claudette makes landfall

The system formerly known as Potential Tropical Cyclone Three got organized and tropical enough just before landfall (which happened this morning around 2am) for the National Hurricane Center to name it. Here’s the radar composite as of 6am ET:

MRMS Composite Reflectivity, 602am ET, sat 19 June 2021. Click to embiggen

The biggest story for the next few days is rain. Here is the HPC seven day forecast, which includes the impact of a strong front expected to arrive in the region Tuesday …

HPC Seven Day Rain Forecast (19-26 June 2021)

As you can see, a foot of rain is forecast for parts of coastal Alabama and Mississippi, and upwards of 6″ into central Georgia. This will cause some scattered flooding, so beware.

Here is the forecast for Claudette. Some pretty big changes since yesterday in the long term – rather than dissipating over the southeast, the circulation is expected to survive and reach the Atlantic and regenerate before following Bill’s track to Vinland (Newfoundland) and Nova Scotia. May get a bit blustery up there, but by then the extratropical transition should be well underway so the worst should stay offshore.

TAOS/TC simulation based on official NHC forecast as of 5am Saturday.

For Coastal Georgia/SC, this will mostly be a rain event, with some gusty winds right on the ocean as we will be on the fringes Sunday and Sunday Night. Heavy rain is possible, and the local Charleston Weather Service office mentions the potential for a tornado, but the risk is small. Still worth keeping your weather radio close by … will be watching tomorrow.

Tropical Storm Dolores; Gulf PTC

The storm churning the fetid waters of the Gulf of Mexico is still trying to organize this morning, and the NHC forecast didn’t really change at 11am Friday (a reminder for those following on social media, always be sure to check the times of posts; platforms like Facebook usually don’t show you things in chronological order!). PTC3 is still forecast to become a tropical storm before landfall tomorrow. In the East Pacific, we now have Tropical Storm Dolores, forecast to make landfall in Mexico on Monday. It may be just below hurricane force if it stays offshore. Hurricane watches are now in place for parts of Mexican coast just in case. Here’s the impact swath for both storms …

11am forecast updates: click to embiggen

For PTC3, the earlier advice still holds. For Dolores, if you are in the swath, prepare for a minimal hurricane just in case. The impact zone is south of Puerto Vallarta, although almost 2 million people could potentially experience minimal tropical storm winds, there under 20,000 people forecast in the strong tropical storm (over 50 knots) or hurricane wind zone (if it reaches that intensity briefly).

PTC Three to make “landfall” early Saturday in #Louisiana

The forecast for Potential Tropical Cyclone Three (AL032021) hasn’t changed much since yesterday. The large, disorganized system doesn’t look like much this morning, with no clear center of circulation, although it is somewhat better than yesterday. Winds are up a bit to just below tropical storm strength. The center seems to be forming just to the left of the orange blob of clouds just south of Louisiana …

GOES East Infrared and GFS short term forecast for 850mb wind/height

NHC still feels the storm will develop a closed circulation before landfall, and thus be designated Tropical Storm Claudette before landfall. Here is the latest impact swath and warnings:

TAOS/TC impact swath based on 5am NHC Forecast, Friday 18 June 2021

As a reminder, the best summary of the “official word” on storms is the NHC’s “Key Messages” product, available at this link. There are tropical storm warnings up for the Louisiana, Mississippi, and Alabama coasts. As for my interpretation, although the storm may reach tropical storm strength, this still won’t be the typical tropical storm/hurricane scenario. That’s why I put “landfall” in quotes above. It will be blustery right on the coast with some waves and minor coast flooding – and this will be well east of the center, the worst of it in the orangish area shown in the above simulation – but again the story here is likely to be a lot of rain in an already wet and nearly saturated area. Rain totals east of the track could range from nearly 10″ on the LA/AL coast to between 2 and 4 inches as far inland as Atlanta. So if you live in an area the floods with heavy rains be aware. Otherwise, scattered power outages, some limbs down, that sort of thing is what to expect …

Potential Tropical Cyclone #Three

The National Hurricane Center has started advisories on Potential Tropical Cyclone Three (AL032021). It’s a very large system, and while it may get more organized as it approaches the northern Gulf of Mexico, this isn’t really a traditional hurricane threat. There may be tropical storm force conditions right on the coast, but the big worry here is a lot of rain from Louisiana up through the southern Appalachian Mountains. Here’s the impact swath based on the first advisory at 5pm ET Thursday …

Click to embiggen …

There are tropical storm warnings up for the Louisiana, Mississippi, and Alabama coasts, although the storm isn’t really close to tropical storm strength according to the latest data and may well not reach that threshold. It may be blustery right on the coast with some waves and minor coast flooding – and this will be well east of the center, maybe even as far as the big bend area of Florida as shown in the above simulation – but again the story here is likely to be a lot of rain in an already wet and nearly saturated area.

The Thing In The #Gulf

The broad area of disturbed weather in the Bay of Campeche continues to be a broad area of disturbed weather in the Bay of Campeche. It should begin to move more decisively northward today, and NHC rates it as a 90% chance of becoming a tropical depression or tropical storm later today or tomorrow. The models continue to have trouble tracking the system, and run-to-run consistency isn’t great other than “some kind of system will move north and drop a ton of rain on the northern Gulf Coast.” For what it’s worth here’s the latest spaghetti map:

Various track models. Click to embiggen …

Even more so than usual with weaker, less organized storms, the model track lines are not the main thing to worry about. The models continue to show upwards of a foot or more of rain being dropped in Louisiana. Here’s the latest analysis from the US National Center for Environment Prediction (the division within the weather service responsible for the global computer models):

HPC Seven Day Rain Accumulation

As noted yesterday, the main risk here isn’t storm surge or wind as this is likely to not become much more than a tropical storm. The problem will be rain in LA, MS, AL, and potentially western Florida and Georgia. Also note that this is likely to remain a very large system, impacting most of the southeast over the next 5 or 6 days.

Watching the #GulfofMexico

As of Wed. morning, the US National Hurricane Center has a disturbance in the Gulf tagged with a high chance of becoming a tropical depression or greater in the next five days – 90% as of the 8am ET update – then moving north into the Texas coast, spreading heavy rain across Texas, Louisiana, and Mississippi. Most of the models have not been as enthusiastic; the GFS lowtracker consistently kills the circulation off in the next 12 hours, before it drifts north back into the Gulf. Here’s the latest (06z) GFS simulation tracks:

The Navy GEM model (which ordinarily isn’t the most reliable of the global runs) is closer to the NHC scenario:

So what to do? This isn’t likely to be a catastrophic event, mostly just a lot of rain. Of course, that could be a problem with river flooding across the region. The New Orleans WFO has a good perspective:

… there should be a few points to remember. 1) until there is a well-defined circulation for the models to initialize (if one develops), guidance is likely to jump around on details, 2) with weak systems, impacts, especially heavy rainfall, can be significantly displaced from the center of circulation, and 3) it doesn`t take a named tropical system to produce heavy to excessive rainfall events in our area.

NWS WFO New Orleans Discussion, 346 AM CDT Wed Jun 16 2021

So we’ll have to wait and see what happens tomorrow, when the northward movement is supposed to start. That puts the major impacts in the US on Saturday. If you live in an area near the Gulf Coast (and 200 miles or so inland) where it floods if you get heavy rain, worth paying attention to.

Tropical Storm #Bill, #Gulf of Mexico, Earthquakes in the #Philippines

It suddenly got busy from a storm and earthquake hazard standpoint, although so far not anything catastrophic. Starting with Tropical Storm Bill (AL022021), like his namesake, the world famous lead tongue for Billy and the Boingers, he is too fast to live and too gross to die. Bill is only marginally a tropical storm – the winds are above the threshold, and it has convection (thunderstorms) but the structure is really a hybrid. It is currently forecast to make landfall in Vinland (Newfoundland) while dissipating, impacts should be minimal, just a blustery and rainy day … click any graphic to embiggen:

Elsewhere in the Atlantic and East Pacific, Tropical Depression Carlos is a fish storm in the open ocean and should dissipate without incident. There is an invest area (AL94) off the coast of Africa that shouldn’t amount to much. But there is an area to watch in the Gulf of Mexico. It is presently over a somewhat favorable area as it meanders over the southern Gulf. While previously forecast to move inland over central america, it is now expected to migrate north. It has some opportunity to become a tropical depression before reaching the northern Gulf Coast (Louisiana/Mississippi area). But more than likely this is just going to be a rain event no matter where it ends up. Here is an overview with the NEDSIS formation potential analysis in greens and yellows:

In the geophysics realm, there has been a while series of earthquakes on Mindanao, Philippines. No reports of significant damage or injuries at the moment, but these were shallow enough and strong enough to produce damage, and I expect reports will filter in over the next couple of days …

The deep dark area just to the right of the Philippines is the Philippine trench, part of the “Ring of Fire” that encircles the Pacific Plate. It is a subduction zone that has produced some devastating events in the island.