Summer arrives as Cindy bears down on Gulf Coast

June solstice

Fun facts about the summer solstice from the National Weather Service. (Credit: NWS-Miami)

The summer solstice slipped into South Florida without much fanfare, arriving Wednesday at 12:24 a.m. EDT for an extended stay until Friday, September 22.

From a visual perspective, there aren’t`many changes to South Florida seasons. If you take a photograph of outdoor foliage on June 21 and compare it side-by-side with a picture of the same area from January 21, you’d be hard-pressed to say which is which, unless you see poinciana trees in bloom or mango trees heavy with ripe fruit.

There are, of course, some subtle and not-so-subtle differences, the main ones being summer’s ultra-high humidity and dew points, and the other being the length of the day.

You would think that the sun sets latest on the solstice, but for various reasons it does not. Sunset in West Palm Beach on June 21, for example, is 8:17 p.m., but there’s a stretch of days from June 27 to July 6 in which the sun sets a minute later, at 8:18, before it begins the long march backward toward the winter solstice on Thursday, December 21.

(In Fairbanks, Alaska, the sun rose Wednesday morning at 2:59 a.m. and will set Thursday morning at 12:47 a.m.)

Temperature changes throughout the Florida summer, especially on the coasts and in the Keys, are almost imperceptible. The normal high in Miami on June 21 is 90, and that falls to 89 on September 21. The normal low on both days — both the start of the summer and the end of the summer — is 76.

Nature, of course, always has some surprises in store, generally in terms of tropical weather.

But otherwise summer’s arrival is a sure sign of lighter traffic, shorter waits at restaurants, and an overall slower pace that can be refreshing despite the heat.

And speaking of summer heat, the National Weather Service says high pressure building in from the east will bump up temperatures over the Florida peninsula for the rest of the week, with highs in the low 90s around most of the metro areas. The next chance for rain is Monday and Tuesday when a cold front stalls over North Florida, NWS forecasters in Miami said.

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Most of the heavy rain from Cindy will be to the east, stretching from Louisiana into the Florida panhandle. (Credit: NHC)

TROPICAL STORM CINDY — The system in the Gulf of Mexico doesn’t look much like a tropical storm at all on satellite, but it’s packing winds of 60 mph and could unleash torrential rain on southern Louisiana, the National Hurricane Center says.

Cindy could cause life-threatening flash floods as it makes landfall in Louisiana early Thursday morning, with the bulk of the precipitation stretched out to the east.

Parts of the western Florida panhandle could get 6-10 inches of rain, forecasters said.

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Florida’s wet weather moves out, balmy summer beach days ahead

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June’s wet weather may finally be on the wane. (Credit: NOAA/ CPC)

Look for a changing of the weather guard over South Florida, with the torrential rains of the past few weeks fading in favor of a more typical July — read drier — pattern.

That’s not to say that the Florida peninsula will return to the dry seasonal precipitation pace that held sway in spring. But the National Weather Service has begun ratcheting down rain chances, especially for East Coast metro areas, into the 20 percent range instead of the 70-80 percent we’ve been seeing.

With Potential Tropical Cyclone Three — a sloppy mess in the Gulf of Mexico that could be named a subtropical storm later on Tuesday — aiming for Louisiana or Texas, and Tropical Storm Bret on a date with dissipation in the Caribbean, the Florida peninsula should be increasingly under the influence of high pressure in the Atlantic.

Forecasters say a stalled cold front over North-Central Florida early next week may deliver another period of showers and storms over South and Central Florida, but all-in-all, better beach weather beckons.

Monthly rainfall totals are in double digits everywhere in South Florida, and respectable totals in East-Central Florida are signficantly above average. West-Central Florida has also had a soggy few weeks, with rainfall totals approaching 10 inches in Tampa, while St. Petersburg-Clearwater is reporting  a fat 14.33 inches for June through Monday.

The Keys are running around 3 inches on the plus side.

But NOAA’s Climate Prediction Center took out its beige marker for the last week in June for South Florida, its graphical forecast map indicating below normal precipitation to round out the month. Central and North-Central Florida may see close to average precipitation.

July is expected to kick off with normal rainfall levels throughout the state.

After a rain-cooled June that brought many Florida locations normal, or slightly below normal, temperatures, above-average heat is likely to fire up again through at least the first week of July, the CPC says.

TROPICS TALK: Looking beyond PTC Three and Tropical Storm Bret, waves continue to roll of the coast of Africa, and the GFS grabs on to one of them for potential development around July 5. But the GFS is infamous for jumping the long-range gun.

The European model (ECMWF) shows clear sailing  over the next 10 days and even the hyperactive Canadian model (CMC) is subdued, save for the suggestion of a Mid-Atlantic system as the month ends.

RECORD WATCH: The low in Melbourne on Monday was 78 degrees, which set a record for the warmest minimum temperature for the date, beating the old mark of 77 set in 2012.

TS Cindy

UPDATE: The National Hurricane Center finally upgraded Potential Tropical Cyclone Three to Tropical Storm Cindy at 2 p.m. EDT. The storm was bound for a landfall early Thursday morning around the Louisiana/ Texas border, forecasters said. Winds were clocked at 45 mph in the Central Gulf of Mexico and Cindy was stationary. In the Caribbean, Tropical Storm Bret was downgraded to a tropical wave as it sped west at 23 mph. (Image credit: NHC)

Tropical Storm Bret forms in Atlantic; Cindy may be lurking in Gulf

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Tropical Storm Bret, above, is forecast to dissipate in the Central Caribbean on Wednesday. Potential Tropical Cyclone Three, below, is expected to become Tropical Storm Cindy and impact the northern Gulf Coast on Wednesday. (Credit: NHC)

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Bret — the second named tropical storm of 2017 — spun up off the northern coast of South America on Monday, the National Hurricane Center said.

Two land areas in the Atlantic Basin were actually under simultaneous tropical storm warnings Monday under a new NHC policy that triggers advisories for systems that haven’t formed. The agency expects Tropical Storm Cindy to roll on to the coast of Louisiana on Wednesday.

Tropical Storm Bret was racing toward the northern coast of Venezuela and the southern Windward Islands at an incredible 30 mph, compounding difficulties in finding a center of circulation for an Air Force plane investigating the system Monday afternoon.

Tropical storm warnings were posted for Trinidad, Tobago, Grenada and parts of Venezuela. Watches were posted for the islands of Bonaire, Curacao and Aruba.

At the same time, tropical storm warnings were in effect for an area on the northern Gulf Coast from Intracoastal City, Louisiana to the mouth of the Pearl River separating Louisiana and Mississippi. Watches were in effect for Intracoastal City west to High Island southwest of Beaumont, Texas.

Bret was finally moving toward the west-northwest and had reached 9.4N 59.8W after spending much of its trans-Atlantic life close to the equator at 5N. Winds were clocked at 40 mph.

Meanwhile, the Gulf of Mexico low pressure area, formerly known as 93L, was upgraded to PTC Three — that’s Potential Tropical Cyclone Three. It was forecast to become Tropical Storm Cindy on Tuesday as it spins northward in the Gulf.

It will be inland over Louisiana by the end of the week, the NHC predicted.

Cindy could make landfall as far west as the northern coast of Texas, forecasters said, with the main impact being heavy rain. The storm was expected to top out with winds of 45 mph.

“Given the disorganized nature of the circulation and the fact that the wind and rain hazards extend well north and east of the center, users are encouraged to not focus on the details of the track forecast,” NHC forecaster Michael Brennan said in a 5 p.m. advisory.

At 6 p.m., PTC Three looked on satellite to be a disorganized trough of low pressure, with the heaviest convection stretching all the way from the southeastern Gulf, west of Key West, all the way down to Belize.

Officially, the center of circulation was plotted at 24.7N 88.7W. It was moving north at 9 mph and top winds were estimated to be 40 mph.

Tropical system moves into Gulf; Saharan air likely for South Florida

93L Sat

The poorly defined center of Invest 93L was near the northeastern tip of Mexico’s Yucatan Peninsula on Monday morning. (Credit: NOAA)

The week begins with an alphabet soup of tropical weather in the Atlantic, and forecasters glued to incoming data to see how it all unfolds. There’s PTC Two or 92L east of the Windward Islands — and then there’s 93L, which could become TD Three … or could it become PTC Three?

And which ones will become Bret or Cindy? None of the above?

National Hurricane Center forecasters predict Potential Tropical Cyclone Two will become Tropical Depression Two, or perhaps Tropical Storm Bret, by late Monday. But after moving through the islands the storm is forecast to throttle down — and eventually dissipate — in the Central Caribbean.

Even if it would survive in some form, forecast models are nearly unanimous in bringing the system or its remnants into Central America. It should have no impact on Florida weather.

The system off the Yucatan, 93L, has been pushing a few bands of showers and storms across South Florida since Sunday. The NHC gives it an 80-90 percent chance of becoming a tropical depression or tropical storm over the next two to five days.

The GFS has 93L making landfall in southeastern Louisiana on Thursday morning. The European continues to take the system into northern Mexico or South Texas on Thursday; the Canadian model (CMC) and Navy model (NAVGEM) take it into the northern Gulf Coast near the Texas/ Louisiana border on Thursday night.

Of the hurricane models, the HWRF takes a bit stronger 93L into Louisiana late Wednesday night.

Based on these forecasts, NOAA’s Weather Prediction Center is forecasting just under 10 inches of rain this week in coastal Louisiana, with up to 5 inches of rain in the western Florida panhandle.

Although the northwestern Florida peninsula may get as much as 2 inches of rain through the week and into the weekend, South Florida should see much lighter amounts, especially on the East Coast.

“The forecast will continue to depict a typical summertime weather pattern with increasing high pressure over the western Atlantic bringing easterly-southeasterly flow across the state,” the National Weather Service in Miami said in Monday’s forecast discussion. “Also, by Wednesday night and into Thursday, there are increasing chances of an intrusion of Saharan dust and drier air into the region.”

Palm Beach International Airport picked up a third of an inch of rain Sunday, pushing June totals over the 10-inch mark for the first time since January 2014. Miami, Fort Lauderdale and Naples have had almost a foot of rain as of Sunday (11.81, 11.49 and 11.95 respecitvely).

One positive effect of all the rain is that June temperatures have been running about 1-2 degrees below normal in West Palm Beach and Fort Lauderdale. The average high in West Palm Beach has been 86 with an average low of 74. Although that sounds comfortable, dew points have been very high.

June temperatures in Miami and Naples have been slightly above average, however.

Temperatures in the Keys have been right around the normal mark.

Hurricane Center issues first advisory for ‘potential’ tropical cyclone

PTD Two

The first ‘potential’ tropical cyclone was being monitored by the NHC Sunday. (Credit: NHC)

The National Hurricane Center began issuing advisories for a tropical system that hasn’t even formed yet — a first for the agency that introduced a new category to the NHC forecasting arsenal.

“The National Hurricane Center now has the option to issue advisories on disturbances that are not yet tropical cyclones, but which pose the threat of bringing tropical storm or hurricane conditions to land areas within 48 hours,” the 5 p.m. EDT advisory said.

“Under previous policy this was not possible. These systems are known as Potential Tropical Cyclones in advisory products and are numbered from the same list as depressions.”

The NHC said the system would peak as a 50 mph tropical storm by early Tuesday morning before losing punch in the eastern Caribbean.

“Quick weakening is expected after that time as southerly shear increases dramatically while the system moves into the eastern Caribbean Sea,” forecaster Michael Brennan said. “The system is forecast to become a remnant low by 72 hours and dissipate by day 4.”

The advisory was published under the heading, “Potential Tropical Cyclone Two Advisory Number 1.”

The government of Barbados issued a tropical storm warning for Barbados, St. Vincent and the Grenadines, the NHC said.

The NHC was still giving the system a 70 percent chance of reaching full tropical depression status in 48 hours. If it does become a tropical storm, it would be named Bret.

Tropical storm conditions were expected in the affected islands Monday night and Tuesday morning, with 2-4 inches of rain expected.

The agency gave the low pressure system off the coast of the Yucatan Peninsula — Invest 93L — a 70 percent chance of becoming a tropical depression or storm by Tuesday and a 90 percent chance by the end of the week.

An investigation of 93L by Hurricane Hunter aircraft was canceled on Sunday and rescheduled for Monday. Forecast models were focusing on an eventual landfall from the Florida panhandle to southeastern Louisiana.

Depression or tropical storm may be brewing in Caribbean, Hurricane Center says

Caribbean sat

Invest 93L in the Caribbean looked robust Sunday afternoon. (Credit: NOAA)

Convection with Invest 93L, the low pressure area that was struggling all weekend off the coast of Central America in the Caribbean, appeared to crank into high gear Sunday morning and the National Hurricane Center upped its chances of development to 90 percent.

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Forecast tracks for 93L. (Credit: SFWMD)

New forecast models showed more of a northern movement with a few of them aiming for the Florida panhandle.

Intensity forecast models keep the system relatively weak, with borderline tropical storm strength at best.

Still, the storm could be a big rainmaker for the northern Gulf Coast, with more than 4 inches forecast next week for southern Louisiana and 3.4 inches for Florida’s Big Bend area. The rest of Florida’s West Coast would receive a little over an inch in the south to more than 2 inches north of Tampa — but these numbers from NOAA’s Weather Prediction Center will be undoubtedly refined as the system moves into the Gulf of Mexico.

The NHC may send a Hurricane Hunter aircraft into the system later on Sunday to see if a closed low has already formed. If it has, it could be the season’s second tropical depression or Tropical Storm Bret.

To the east of the southern Windward Islands, Invest 92L continued to chug west at 20 mph, a bit fast for tropical development. Forecasters said the chances of development were 50-50, and had a Hurricane Hunter standing by for Monday to check it out if necessary.

Forecast models are very consistent in bringing 92L into the western Caribbean by the end of the week, although its biggest challenge will be to survive the eastern Caribbean, which often has hostile conditions.

Rain chances are high in South Florida for the beginning of the week — up to 70 percent — before tapering off to 20 percent by Friday.

“The forecast for South Florida could be adjusted to reflect even higher POPS for the first half of the week if this feature moves closer to the state,” National Weather Service forecasters in Miami said in their Sunday analysis.

National Weather Service forecast offices in Florida are still talking about an influx of drier air to end the week.

 

Hurricane Center goes code red on two Atlantic systems

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UPDATE: Early forecast models for the Caribbean low pressure system, which was designated Invest 93L by the National Hurricane Center Saturday afternoon. (Credit: NHC)

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Forecast development areas for Invests 92L (right) and 93L. (Credit: NHC)

National Hurricane Center forecasters got out their red markers on Saturday to announce a high chance of tropical development for each of the two areas of disturbed weather in the Atlantic.

Model wars continued between the European (ECMWF) and NOAA’s GFS, the latter of which has changed its forecast track for the low in the western Caribbean from Texas/ Mexico to the Florida panhandle. This is echoed by the Canadian (CMC) — the Rodney Dangerfield of tropical forecast models, which doesn’t seem to get much respect among weather professionals and amateurs alike.

But it’s interesting that the CMC has been the most consistent with the Caribbean low in keeping it in the Eastern/ Central Gulf of Mexico and spinning it into the northern Gulf Coast.

On the other hand, the gold-standard ECMWF still projects that the Caribbean low will slide across the Yucatan Peninsula, into the southwest Gulf and eventually make its way into Mexico or Texas.

The question is whether the ECMWF will begin trending east to catch up with the rest of the pack or if the others will see the errors of their ways and join the European in supporting the system’s western march.

On Saturday morning, you could be forgiven for thinking that it was much ado about nothing, since the showers and storms in the western Caribbean seemed to lack any organization at all. In fact, the heaviest rainfall was occurring south of eastern Cuba and near Jamaica, with very little activity near the coast of Central America.

Nevertheless, NHC forecasters give this area a 70 percent chance of becoming a depression or tropical storm by around mid-week. In their Saturday morning Tropical Weather Outlook, they did expand their red cone of development area a bit to the northeast, probably in deference to the GFS.

As for Invest 92L in the Central Atlantic, this system also earned an upgrade to a high chance of development — 70 percent — although some of the tropical waves behind it looked more robust.  (Development chances were downgraded to 60 percent Saturday afternoon). Most forecast models show 92L eventually rolling across the Caribbean and approaching the Yucatan, although a couple of outliers take it over Cuba or Hispaniola.

At this point, nothing suggests a threat to Florida from 92L.

If the western Caribbean low can manage to get its act together sufficiently this weekend, it will be tagged Invest 93L and then we’ll get the benefit of some of the more specific hurricane models, such as the HWRF.

The National Weather Service in Key West sums it up: “Still a tale of two camps between the 00Z ECMWF & GFS, which present different impacts given the associated track of low pressure yet to develop. In the case of the ECMWF, the model subsequent model runs continue to develop low pressure near the Yucatan and then move it more northwestward across the Yucatan Peninsula into either the Southwestern or South-central Gulf of Mexico.

“In this case, the best confluent bands of heavy showers and scattered thunderstorms could only graze the Lower Keys with heavy rainfall, with most of the heavy rainfall moving by to our west. In the case of the GFS solutions, the lower pressure that eventually develops, does move more north northwestward towards the Yucatan Channel and into the Southern Gulf. This scenario allows deep moisture and good confluence bands to move across Central and Western Cuba and to across all of the Keys. So we would include potential for locally heavy rainfall.”

Eastern Atlantic waves

Is this June — or August? Strong tropical waves keep emerging off the coast of Africa, more typical of late summer. (Credit: NOAA)

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LONG-RANGE: Will the Florida peninsula start to dry out over the next week or so? That’s still the picture painted by National Weather Service forecasters in Miami, who say a strengthening Bermuda high and an intrusion of Saharan air will hit the shut-off valve on nature’s rainfall faucet — at least for the East Coast — by late next week.

In the meantime, rain chances remain in the 50-70 percent range through mid-week, before falling to around 30 percent by Friday night.

The last week of the month may kick off a pattern change to drier July weather — if there are no tropical surprises.

Friday’s storms brought up to 2 inches of rain along parts of the East Coast from Broward County all the way up to Volusia County. The Tampa area received about an inch, according to the Community Collaborative Rain, Hail & Snow Network.