Matt Lanza

Next wave of heavy rain pushing across South Florida, as high flooding risks continue

Headlines

  • Additional heavy rain is likely in Florida today, with a high risk for flooding and excessive totals in South Florida, including the Miami and Fort Lauderdale areas and Naples also.
  • Rain, ideally more manageable, will shift to Louisiana, Texas, and Mexico next week, while a separate tropical system may form in the Bay of Campeche and track into Mexico.
  • An additional tropical entity may try to form the week of June 24th in the western Gulf.

Florida flooding risks still not over

After a wild day yesterday with flash flood emergencies posted between Miami and West Palm Beach, we’re seeing the next round of heavy rainfall pushing across the Peninsula from northwest to southeast.

Rain will continue to drench the Florida Peninsula today, with more flooding likely in parts of South Florida. (College of DuPage)

Yesterday was the third wettest day since 2000 in Fort Lauderdale with 9.54 inches of rainfall. It was Miami’s fifth wettest day since 2000 with just over 6 inches of rain. So far this week, some parts of the immediate coast have seen upwards of 20 inches of rainfall.

Around 16 to 20 inches of rain has fallen this week north of Miami Beach. (NOAA NSSL)

North Miami has had 20.43″, Hallandale and Hollywood are over 19 inches, and not to be outdone, Big Cypress National Preserve in Collier County has seen 25 inches of rain!

Today should hopefully the last really dicey day for Florida, but it’s definitely not looking great with all this moisture inbound. As a result, the Weather Prediction Center has upgraded South Florida to a high risk of excessive rainfall and flash flooding. Anywhere from 4 to 8 inches of additional rain are possible today, with locally higher amounts. The atmosphere is about as juiced up as you’ll ever see in June in Florida, which means that it will be capable of dumping very heavy rainfall at very high rates.

A high risk of flash flooding exists today between Naples and Miami, with as much as 8 to 10 inches possible in the hardest hit areas. (NOAA WPC)

The hope is that the rain becomes more intermittent and a little less intense for Friday and the weekend. There will still likely be some showers or heavy rain around, but it should space itself out a bit.

Invest 90L’s future murky

Meanwhile, Invest 90L, which helped contribute to the massive rains in Florida yesterday is on its way out over the Atlantic. Odds of development are minimal, and for all intents and purposes, this should be a non-event to monitor.

Invest 90L has a lot of convection (thunderstorms), but it lacks any meaningful organization at this time. (Weathernerds.org)

Next week’s potential Gulf system

Meanwhile, the odds of development in the western Gulf of Mexico continue to inch upwards today. The National Hurricane Center is now assigning a 40 percent chance of development in the Bay of Campeche for next week.

Odds of Bay of Campeche development next week are around 40 percent now, as most modeling suggests a disturbance and environment favorable for something to briefly spin up. (NOAA NHC)

What to make of this? As we’ve been discussing this week, the moisture axis aimed at Florida this week will reorient next week as high pressure sets up over the Eastern U.S., kicking off a pretty significant heat wave for much of the country. This will direct high moisture into Louisiana and Texas, coupled with the developing low in the Bay of Campeche.

Moisture will shift into the western Gulf next week, as tropical development may also occur in the Bay of Campeche. (Tropical Tidbits)

You need to think of this as two separate but related entities. On the one hand, we’re going to see a broad “fetch” across the Gulf allowing for more numerous showers and thunderstorms in Texas and Louisiana perhaps, as well as northern Mexico. The hope is that most of this rain will be manageable in nature with only minor flooding concerns at times. We’ll keep watching.

Rainfall through next Thursday morning will likely be on the order of 2 to 5 inches on the immediate coast, with locally higher amounts possible between Mexico and Louisiana. (Pivotal Weather)

On the other hand, a formal tropical system will likely try to form in the Bay of Campeche, likely also directed west or west-northwest, which pushes it rather quickly ashore in Mexico by later next week. Rain will be mostly welcome in Mexico, which, as we noted yesterday has been mired in record heat and drought. There’s been hardly a cooler than normal day there since April.

More Gulf gyration to come?

We have a little bit of a new wrinkle today, and this involves the potential for a second western Gulf system by next weekend or so. This “gyre” type setup in Central America is causing us headaches, and another disturbance may pivot from the southwest Caribbean to just north of the Yucatan by next weekend. From there it would probably move quickly north toward Texas, Louisiana, or Mississippi.

Potential for another western Gulf system next week is supported to varying levels by both the European and GFS ensemble models. (Tropical Tidbits)

Whether there will be enough time or a stable enough environment for more development to occur, it’s too soon to say. But the timeline is next weekend into early the week of June 24th. We’ll keep you posted.

Gulf of Mexico’s early season party in Florida will move westward next week

Headlines

  • An additional 6 to 12 inches of rainfall is likely to exacerbate developing flooding problems in portions of South Florida.
  • Potential tropical development in the Atlantic from the Florida system is possible but unlikely.
  • Moisture shifts west across the Gulf next week and will impact Texas and Mexico with locally heavy rain.
  • Drought relief likely in eastern Mexico.
  • A potential for a short-lived tropical system in the Bay of Campeche could locally enhance rain totals in Mexico next week as well.

Florida flooding starting to take shape

A 48 hour rainfall map in Florida really tells the story.

Estimated rainfall totals of 8-10 inches or more have popped up near Fort Lauderdale, rural southwest Florida, and most notably in Sarasota. (NOAA NSSL)

Sarasota in particular has seen some pretty rough flooding. The highest total through earlier this morning was 11.38″ just southeast of Sarasota. Radar shows heavy rain continuing to push east or east-northeast across Florida in a pretty stable fashion. That means a continued dumpage of rain for the region.

Rain, heavy in spots continues to push east-northeast across South Florida today, with a good bit more coming. (College of DuPage)

How much more rain is coming? A lot. Flooding problems are likely to get worse across Florida in the coming days, and flood watches are hoisted from Bradenton south and east to Miami and into the Keys.

An additional 6 to 12 inches of rain is likely in South Florida, and there will certainly be localized higher amounts. Those will be the areas most likely to see bad flooding. (Pivotal Weather)

With another 6 to 12 inches of rain on the rain, it’s safe to say flooding is likely at times and in spots, especially those areas that see localized higher amounts. This is a true firehose of moisture the next few days, eradicating drought and causing new problems.

Atlantic development possible but probably unlikely

We are still watching for potential that we can spit out the A-storm or a depression from the morass over Florida. Low pressure will push off the coast today and into the Atlantic over the next few days. It’s been dubbed Invest 90L. As a reminder, “invests” are convenient ways for meteorologists to run some extra modeling on disturbances that may become tropical systems. The list cycles from 90 to 99L in the Atlantic and then starts over again. Invest 90L is our first of the season.

As it scoots northeast, we’re still hanging around a 20 percent chance from the National Hurricane Center that we see a tropical system develop from this.

Invest 90L may develop over the next few days, but the odds seem very low, and no impacts to land are expected. (NOAA NHC)

Personally, I don’t see it happening, but for those who are interested in mostly meaningless tropical activity, we can watch it over the coming days.

What’s going to happen in the western Gulf?

The next phase in our party in the Gulf will be this moisture plume shifting directions. We can track this by using the GFS model’s precipitable water forecast (PWAT). PWAT is basically a measure of how much moisture is available in the atmosphere. Once you get up over 2 inches or so, you’re talking about a very, very juiced atmosphere capable of big time rainfall. Over the next 8 days (based on the most recent GFS model that came out this morning), we can see how the plume shifts to focus on the central Gulf Coast, then Texas, then Mexico by later next week.

Precipitable water forecast from the GFS model today showing moisture pivoting across the Gulf from Florida this week to Mexico by late next week. (Pivotal Weather)

The good news for Louisiana and Texas is that this appears to keep moving, eventually setting up in Mexico as we see potential tropical development in the Bay of Campeche next week. As of right now, the NHC has given that area about a 20 percent chance of developing once it establishes there next Sunday or Monday or so. Based on most available operational model and ensemble model guidance, we would expect any development to be rather sloppy and quickly come inland over Mexico, probably near Tampico, give or take. Obviously, we’re a week out so things will change, but that’s the best guess right now.

Meanwhile, as all that moisture comes west, a couple important things will happen. First, we could see locally heavy rainfall along the Gulf Coast. These types of scenarios often lead to the first tier of coastal counties getting drenched while the next tier of counties inland has slightly less intense rainfall.

Rainfall totals of 2 to 5 inches are expected through next Wednesday morning, with slightly higher amounts possible near Port Arthur, Galveston, Corpus Christi, or Brownsville. (Pivotal Weather)

As of now, we’ll say 2 to 5 inches on the coastline between Mobile, AL and northern Mexico, with higher amounts possible in localized areas on the Texas coast. Interestingly, Mexico could see significant rainfall from this. They had a serious drought heading into last month. And last month was exceptionally hot and dry. So they need rain.

The drought monitor map for Mexico heading into last month; conditions have only worsened since. (US Drought Monitor)

The hope is that it won’t be too much rain too fast. But at least this should help eastern Mexico begin to slip out of drought. It will also allow for cooler weather across Mexico, something that area could use as well.

Despite some gnarly weather model runs, the situation in the Gulf of Mexico looks more wet than whirly

Headlines

  • Flood watches now in Florida with 5 to 15 inches of additional rain on the way to the south through Saturday.
  • Some slightly potential that a disturbance can form into an organized system as it moves out into the open Atlantic.
  • Moisture shifts into the central and western Gulf next week with locally heavy rain possible.
  • Continuing to watch the western Gulf next week for potential development next week, but recent GFS “scareicane” runs are likely illegitimate.

Florida focus

The main near-term concern remains the rain in Florida. A flood watch is now posted for South Florida through at least tomorrow evening.

Flood watches are now in effect for South Florida through Wednesday night, including Naples, Miami, Fort Lauderdale, and West Palm. (NWS Miami)

Mostly minor amounts fell yesterday, with the heaviest right near Titusville to the east of Orlando, where radar estimates around 5 inches of rain occurred. Heavy rain also occurred between Bradenton and Fort Myers as well. Heavy rain is pushing into the Southwest coast this morning, and additional rounds of rain are likely through the day. Some localized flooding issues may crop up today. It’s the piling up of rain totals that will eventually shift this from a localized flood risk to a slightly more widespread one.

Additional rainfall expected by the NWS over the next week, with 10 to 15 inches on the southwest coast and 5 to 10 inches elsewhere in South Florida. (Pivotal Weather)

Additional rains of 5 to 15 inches are expected across South Florida from this morning into probably Saturday before things settle down. Locally higher amounts cannot be ruled out.

What’s next for the moisture plume?

We’ve got two aspects of this thing to watch. The first, and perhaps the best chance of tropical development over the next week is this disturbance crashing into southwest Florida this morning. It is expected to cross the Peninsula, emerge north of the Bahamas and may have a window of opportunity to develop into something in the Atlantic as it exits out to sea. This isn’t an especially uncommon early season mode of tropical formation, so this makes sense.

The National Hurricane Center is giving this disturbance crossing Florida today about a 20 percent chance of development as it emerges north of the Bahamas and scoots out to sea. (NOAA NHC)

The NHC is offering up only 20 percent odds of development today with this as it scoots out to sea. This seems to be as good of odds as are necessary at this point, but it is our best development opportunity through the weekend.

The second aspect of the moisture plume is where it actually ends up next. It abruptly shifts off Florida beginning Saturday as high pressure begins to build in from the west. This should help dry Florida out a bit after Saturday.

Sunday evening’s upper air map from the European ensemble shows high pressure building over Florida and an upper-low over the Bay of Campeche. This should allow the moisture “firehose” to get directed toward the Central Gulf Coast initially. (Tropical Tidbits)

This shift will allow the “firehose” to move west and focus on the central Gulf Coast by later Sunday or Monday. This should allow for locally heavy rainfall between Pensacola and New Orleans and at least some localized flash flooding potential.

From here, things get tricky. The European suite of modeling focuses in Texas next week, with its AI model aimed near Houston and the traditional operational model aimed at the Corpus Christi area south into the Rio Grande Valley. It’s tough to get a good signal in the ensemble modeling with a focus on the Louisiana coast within the GFS ensemble and a focus somewhere broadly in Texas or even Mexico on the European. Much, if not everything will depend on exactly how the weather pattern over the U.S. evolves next week. Stay tuned on this.

What of the late period GFS “Scareicane?”

Avid model watchers will note the sub-960 mb low that emerged in the Gulf of Mexico on a couple GFS operational model runs yesterday. Suffice to say there is little to no support for that particular outcome from any other weather model. And, in fact, the last two GFS model runs did not contain that feature. As a reminder, that is a normal GFS June bias to explode tropical systems unnecessarily strong in the Gulf. Bottom line: We offer it little to no credibility.

That being said, there does continue to be support for broad low pressure somewhere in the western Gulf of Mexico next week.

Normalized sea-level pressure anomalies over the western Gulf of Mexico remain low during days 6 through 10, but trying to extract a specific tropical entity from this soup will be a bit challenging. (Tropical Tidbits)

But whether or not we’re able to pull a specific system out of this general unsettled soupy mess of moisture remains to be seen. I think that potential next week is legitimate, but I think the ceiling on intensity is capped. We’ll keep watching this. In the meantime:

  • The GFS operational scare runs from yesterday are likely illegitimate.
  • There is broad support for something potentially in the western Gulf next week.
  • If something does develop, most likely it’s a strung out, sloppy storm and whether it goes toward Mexico, Texas, or to the north remains to be seen.

Stick with us as we watch!

A very unsettled, moisture-filled Gulf of Mexico remains the focal point of the next couple weeks

Headlines

  • Significant increase in rain chances for Florida this week will likely begin to lead to some flooding concerns, mainly for the Peninsula.
  • A firehose of moisture should begin to extend north and west from the FL Peninsula next week.
  • Portions of Florida will likely see 10 to 15 inches of rain or more through next week with chances of double digit rainfall totals expanding to the west in time.

Gulf moisture surge ahead

Put simply: The next 10 to 14 or so days in the Gulf of Mexico will feature a firehose of moisture that is likely to have wide ranging impacts from Florida to perhaps Texas. Ultimately this may serve as a reminder that a system does not need to be a hurricane or even have a name to cause widespread impacts.

Deeper tropical moisture (In green and blue) will focus on Florida this week and then begin to migrate to the west across the Gulf Coast next week (Pivotal Weather)

What’s the meteorology behind this?

Here’s the basic, high level meteorology of how things will begin to unfold. First, a trough of low pressure in the upper atmosphere is digging into the Eastern U.S. this week. What it will begin to do is draw moisture that’s been percolating in the western Caribbean and Central America northward. As high pressure builds east across Texas and into Louisiana, the focus of this moisture plume will be over Florida. Widespread daily rain and thunderstorms will begin to add up across the Peninsula. Eventually, high pressure may flip flop and end up over the Southeastern US, allowing the moisture plume to begin migrating west across the Gulf, soaking the Florida Panhandle, central Gulf coast, and eventually Louisiana or perhaps Texas.

A deep plume of tropical moisture is going to migrate from Florida this week into the central or western Gulf next week. As it does, heavy rain and at least a low risk of disorganized tropical development will go with it. (Tropical Tidbits)

Where is the rain going?

All modeling agrees that the Florida Peninsula will get doused this week. The models split rather drastically beyond this week. Some aim the tropical moisture more at the central Gulf Coast. Others push it to Texas. There’s very little agreement or consistency in the modeling on this aspect of the forecast, so for now the rain focuses on Florida and by next week we’ll be watching elsewhere.

The exact placement of high pressure will help orient the moisture plume, which is why it’s a bit soon to say what the second round of this does. This is in some ways like forecasting where exactly an atmospheric river will make landfall on the West Coast. You know that there will be a whole lot of moisture coming, but is that going to Texas? Louisiana? Mississippi/Alabama? We don’t know yet.

Will we see a tropical storm or worse out of this?

Most likely no, but it cannot be entirely ruled out. Several model runs on several different models, along with multiple ensemble members on various models have been showing some low-end development. The trouble is that the consistency and persistence of it is far too volatile to lend any specific outcome credibility. This is not a total surprise for June; storms in June are most often sloppy. About 70 percent of all named storms in the Gulf in June end up remaining tropical storms, while 30 percent have become hurricanes. As of now, we’ve got no reason to think a well-organized tropical system will come from this.

It’s probably just going to be rain in Florida then, so it’s not a huge deal, right? Incorrect.

Moisture plumes traversing record warm Gulf of Mexico sea-surface temperatures do not exactly make for optimal combinations anytime of year, let alone June. This moisture has some teeth, and we’ve seen this reflected in some of the maximum precipitation forecasts showing up on operational models. These have ranged from 15 to 25 inches in some cases between about Louisiana and Florida. That would be a lot of rain for anyone. Since we want to focus on the next week, looking at Florida tells the story. Maximum rain forecasts are basically 8 to 20 inches in the southern half of the Peninsula.

The rainfall forecast for Florida over the next week shows nearly 20 inches possible for the southwest, Lee Island, and Paradise coasts. (Pivotal Weather)

While there has been burgeoning drought here, anytime you get this much rain, it causes problems. I would expect flood watches and other notifications to get hoisted this week. If you’re planning a trip to South Florida, all we can tell you is to be prepared for more storms than usual and have some indoor plans setup, especially as this week progresses. And have a way to receive weather alerts.

Elsewhere, no other tropical concerns exist at this time and our focus will be entirely on this Gulf mess through the week.