Matt Lanza

With Rafael out of the picture, a new disturbance may pose a threat to the southwest Caribbean or Central America

Headlines

  • Rafael (mostly) did what it was supposed to do in the Gulf, although it’s unclear if there was a “winner” among the models.
  • A tropical wave has an increasing potential to develop in the Caribbean later this week.
  • This system may pose a threat to Central America either through development into a storm or through a slow-moving heavy rainmaker.
  • It bears close watching between the Yucatan and Nicaragua.

Rafael’s demise

Mostly as expected, Rafael succumbed to wind shear and dry air over the Gulf of Mexico this weekend. Just to tie a ribbon on this whole thing, remember, model guidance was sort of split on taking Rafael southward into the Bay of Campeche or north into Louisiana. The majority of guidance shifted toward the Bay of Campeche track late last week, and the official forecasts all generally pointed toward that happening. Interestingly, when you look at the initialization of the models since Friday, you can see the mid-level signature of Rafael kind of shear apart with some going north and some going south.

The mid-level vorticity (or “spin”) over the Gulf of Mexico associated with Rafael basically got stretched and torn apart, with some going north and some staying put or going south. (Tropical Tidbits)

That said, there was likely some element of Rafael’s moisture that got picked up by a cold front in the Deep South this weekend. Heavy rain and flooding occurred in Louisiana, especially between Alexandria and Lake Charles, with radar estimates in excess of 12 inches since Friday morning.

Much of southwestern and central Louisiana into southwest Mississippi saw as much as 4 to 6 inches of rain with 10 to 12 inches or more between Alexandria and Lake Charles. (NOAA NSSL MRMS)

Heavy rainfall in excess of 4 inches also occurred in eastern Louisiana and even southwest Mississippi. All in all, it was a substantial autumn rain event, perhaps aided a little by Rafael.

Potential trouble brewing for Central America

With Rafael now just a remnant in the Gulf, our attention will focus back to the Caribbean, where we should see a tropical disturbance in about 4 or 5 days or less drifting into the western part of the Sea. The NHC assigns about 40 percent develop odds, and a slow moving system could cause some problems in Central America. Models are divergent on exactly where, what, and when. But in general, a system tracking toward Honduras or Nicaragua seems plausible. Upper level steering currents look to be generally weak. This means that whatever does or does not develop is likely to remain slowly moving in this area.

Potential trouble is brewing for Central America late this week or weekend. (Weathernerds.org)

This means that a couple unideal solutions are on the table right now, ranging from a potentially strengthening system to a slow-moving hefty rainmaker. Neither option usually leads to good outcomes in Central America, so unfortunately this will bear very close watching for those areas between the Yucatan and Nicaragua. For the Gulf, at least initially it appears that high pressure should exert control and effectively close off the area to anything from the Caribbean. So it is not likely to be a concern. But for folks in Central America, watch this one closely.

Hurricane Rafael is a Gulf of Mexico wanderer

Headlines

  • Hurricane Rafael briefly attained 120 mph intensity this morning, matching Hurricane Kate from 1985 as the strongest November Gulf hurricane on record.
  • It now appears to have stabilized and should weaken somewhat as it tracks west, then north, then probably east and south, decaying on the way.
  • While a track north toward the Gulf Coast cannot be entirely ruled out, even the models that do this are in good agreement on substantial weakening between now and then, and even in a worst case scenario, impacts are likely to be minor.
  • Regardless, rip currents, rough seas, and minor tidal flooding is possible this weekend between Texas and the Florida Panhandle.
  • Another system is unlikely north of the Caribbean islands, but locally heavy rainfall is possible between Puerto Rico and Cuba this weekend.

Rafael the adventurer

Hurricane Rafael is certainly a meteorological oddity given the time of year and its intensity. As a 120 mph category 3 hurricane this morning, it became the strongest November hurricane in the Gulf since 1985’s Hurricane Kate, which also matches the strongest November Gulf of Mexico hurricane on record.

Hurricane Rafael is now beginning to weaken after briefly reattaining major hurricane status this morning. (NOAA/NHC)

Rafael is now weakening again, sort of, and it should continue to do so over the next couple days. We’ll see if Rafael has one final burst available to hold or strengthen further, but given model guidance and the extremely hostile environment it’s moving into now, this seems unlikely. But, for now at least, this is clearly still a fairly potent hurricane.

Rafael is still rolling along in the central Gulf of Mexico. It’s less healthy looking than it was earlier today, but it remains a rather potent little storm. (Tropical Tidbits)

Rafael is a bit diminutive, more than it appears from satellite. Tropical storm force winds only extend out about 90 miles right now, with hurricane force winds only around 30 miles from the center. That’s one reason why we aren’t especially concerned about significant impacts far away from the storm. Still, there are coastal flood advisories, rip current advisories, and high surf advisories posted for portions of the Gulf Coast between Florida and Texas. If you’ll be spending a weekend at the beach for Veterans Day, please be careful in the water.

Rafael’s track remains as bizarre as ever, with loops and southward movements all forecast. Ignoring the Canadian model (CMC) on the map below, you can see how Rafael is likely to slow down, turn northward, then eastward, then southward in the coming days as it gets pushed around by high pressure and varying steering currents. This should shove Rafael into the Bay of Campeche next week, while also weakening it as it goes.

Rafael is likely to slam on the brakes, turn north, then east, then south, and meet its demise in the Bay of Campeche. (Tomer Burg)

Understandably, we’ve been snake bitten so much on the Gulf Coast since 2017 that it’s tough to just assume something isn’t a threat. But in this case, there is actually strong, broad model agreement that this is indeed what will occur.

Hurricane model intensity guidance shows a collapse in Rafael’s strength over the weekend. The couple outliers that remain generally aren’t reliable models. (Tropical Tidbits)

Two of the better models in the Gulf this season, the ICON and European AI model do show a track a little closer to the CMC one above, but they are firmly in line with the intensity forecast of a weakening storm. So even in a “busted” forecast where this comes farther north than anticipated, you’d still likely see a moderate to minimal tropical storm at worst with generally minor impacts. We’ll keep an eye on things through the weekend to be safe.

More to come?

Another tropical system has about a 20 percent chance to develop over the next few days near or north of the Caribbean islands. (NOAA/NHC)

Meanwhile, another tropical system is unlikely but there will be something to at least eyeball near the Turks and Caicos and Bahamas. There is a risk of excessive rain for portions of Puerto Rico as this disturbance passes by, in addition to a risk of heavy rain in the Greater Antilles and Bahamas and Cuba in the coming days.

Excessive rain is possible later today and tonight in Puerto Rico, with an elevated risk in the eastern and northwestern portions of the island. (NWS San Juan)

Beyond this, there are hints of another Caribbean system later in the month, but I would not hang my hat on that right now. We’ll keep watching.

Rafael moves along in the Gulf with one of the oddest November forecast tracks you’ll ever see

Headlines

  • Rafael will continue west and eventually turn southwest, steered by high pressure over Florida and the northeast Gulf.
  • Rafael unlikely to cause serious land problems at this point for Mexico or the U.S. Gulf Coast.
  • Higher tides are likely for Texas and perhaps Louisiana, but as we explain below, they will fall well short of levels seen during Alberto earlier this season.
WYD, Rafael? (NOAA/NHC)

Hurricane Rafael doing some unique things for November

Hurricane Rafael is motoring along this morning in the Gulf of Mexico off to the west and west northwest.

Hurricane Rafael is heading west and slowly beginning to feel dry air and some wind shear. (Weathernerds.org)

Rafael is a category 2 hurricane with 100 mph winds, down a bit from its peak on approach to Cuba yesterday. It will likely hold steady or gradually weaken in the next couple days as it tracks west.

A storm tracking west in the Gulf is not uncommon. However it is virtually unheard of in November.

November hurricanes in the Gulf of Mexico. (NOAA)

Only Hurricane Jeanne in 1980 tracked west in the Gulf in November, and interestingly, it followed a very similar path to Rafael, just farther west of Cuba and then died off before getting to Texas or Mexico. Hurricane Juan in 1985 also had a noteworthy track in that it did several loops over the northern Gulf before eventually making a final landfall near Pensacola. But most Gulf storms in November come due north or track northeast out of Central America as weakened systems. Rafael will definitely be a historically noteworthy system.

While a handful of outlier models still linger a weak Rafael in the northern Gulf, our best guidance generally takes Rafael southward into the Bay of Campeche as a slowly weakening system, much like the NHC track at the top of this post. (Tropical Tidbits)

Model guidance is actually in decent agreement today that Rafael will track due west and then inexplicably southwest into the Bay of Campeche. I want to tackle two questions here. First, what in the <redacted> is happening here? Second, someone asked why this storm is not as concerning as Tropical Storm Alberto, which did something kinda sorta similar back in June and caused some considerable coastal flooding on the Texas coast. The two questions are somewhat related.

So, the what is fairly simple to explain. If we look at a map of the upper air pattern, or what will steer Rafael at 48 hours when that turn to the southwest begins, we see high pressure over Florida and the Southeast pushing Rafael to the west.

The upper air map on Saturday morning shows high pressure directing Rafael off to the west. (Tropical Tidbits)

By Monday morning, the high pressure center has moved east of Florida, but it has also kind of strung itself out more. This imparts more of a northeast to southwest type of motion on Rafael. Keep in mind that during this time, Rafael will continue to slowly weaken, so it will also become more susceptible to these steering currents as well, making it easier to sort of “bully” the system into the Bay of Campeche.

High pressure will be directing more of a northeast to southwest steering current on Sunday night and Monday which, when combined with a weakening Rafael should allow it to get shoved into the Bay of Campeche. (Tropical Tidbits)

Is this a threat to Mexico? It seems like it won’t be a real serious threat, but it at least bears some watching to make sure everything behaves as expected.

So this leads us to the second question: Why is this storm not really a major flooding concern for Texas, whereas Alberto was back in June. Here’s what the upper air pattern looked like for that event.

THIS MAP IS NOT CURRENT! A map from Tropical Storm Alberto shows a tighter pressure gradient establishing over the entirety of the Gulf due to both the storm in the Bay of Campeche and high pressure to the north. (Tropical Tidbits)

During Alberto, high pressure to the northeast of the Gulf, combined with low pressure in the southwest Gulf led to a broad, strong pressure gradient flow across the entirety of the Gulf. That is what we call a long “fetch,” meaning moisture and waves had an opportunity to pile up in the western Gulf eventually. That led to coastal flooding in Texas and Louisiana. In Rafael’s case, we have the system in the southwest Gulf, but it’s a bit smaller. We also lack high pressure to the north that would enhance Gulf moisture and fetch. Will tides increase on the Gulf Coast? Probably. Will they reach Alberto levels? Almost certainly not. So this is why we aren’t especially concerned about coastal flooding.

Rafael will hopefully be a meaningless blurb by Monday, but we’ll see. Meanwhile. another weak system has a slight chance to develop north of the islands heading into next week. At this point, we don’t view that as a particularly serious concern.

Rafael chugging into the Gulf Wednesday night, as south Georgia sees severe flooding

Hurricane Rafael hammered Cuba earlier on Wednesday, and it is now on its way west across the Gulf of Mexico.

(NOAA/NHC)

There have been significant forecast changes since yesterday, and it now appears we have two very distinct camps regarding Rafael’s future. Camp 1 takes Rafael northward toward the central Gulf Coast by next week or meanders it in the northern Gulf. Camp 2 takes Rafael west and then southwest around the periphery of a ridge of high pressure over Florida and the Deep South.

Two distinct camps of possible options for Rafael have opened up since early Wednesday. (Weathernerds.org)

It is too early to know which camp is correct, but clearly the NHC forecast near the top of this post is on board with something more like the second camp.

The good news is that there seems to be a clear signal in modeling that the storm will weaken as it transits the Gulf. This is not August. It’s November, and although the waters remain fairly warm, the reality is that wind shear and dry air usually play a big role in November storms. This case should be no different.

Strong wind shear should help disrupt Rafael as it comes west, likely weakening it from a borderline major hurricane to a tropical storm by this weekend. (Tropical Tidbits)

This should allow Rafael to begin to wind down after Thursday, slowly weakening back to category 1 strength and then tropical storm strength this weekend.

From that point of view, any threats to land from here seem limited. However, folks in Mexico and on the central Gulf Coast should continue to watch Rafael’s progress to see if anything changes.

Apologies for the extremely late update on Rafael today. A sick kid and a day full of obligations will do it!

Valdosta flood emergency

The Valdosta/Lowndes County area of Georgia is being blasted by rainfall this evening with a flash flood emergency in effect. Streamflow values are extreme right now over Valdosta itself.

Extreme streamflow values noted around Valdosta likely correlate to severe, catastrophic flash flooding in that area. (NOAA NSSL MRMS)

Return periods on some these rainfall values are in the 250 year or higher range, meaning this is an exceptional event for Valdosta. Rain totals are in the 6 to 10 inch range as estimated by radar for Valdosta today.

Valdosta has seen anywhere from 6 to perhaps 10 inches of rainfall today. (NOAA NSSL MRMS)

We have been warning of potentially localized flash flooding in Georgia or South Carolina for a couple days now, and that’s indeed what has happened. Numerous other flash flood warnings are in effect across the region, including some serious ones not far from Valdosta right now also. Thankfully, the rains should hopefully wind down in the next 2 to 4 hours.