Contemplating a South Florida fall

Students are heading back to school over the next couple of weeks, and there are already some Halloween displays at stores. The NFL played its first pre-season game on Thursday.

AccuWeather published its fall forecast on Thursday with the word “snow” plastered over the Rocky Mountain States.

In South Florida, fall is more of a concept than an event, but there are some subtle changes that take place.

To wit: The normal high in West Palm Beach, 91 since July 31, edges down to 90 on Tuesday. That doesn’t exactly portend a breath of fresh air, but it’s the first downward adjustment of the normal high temperature since January 18. Florida is surrounded by hot water in the fall, and the high of 89 on August 30 only ticks down to 87 on September 30.

Miami’s high remains at 91 until August 29, and hits 88 on September 30. Fort Lauderdale’s normal high of 91 edges down to 90 on August 17, while Naples’ normal high doesn’t fall to 90 until September 3, and it doesn’t hit 89 until September 25.

Overnight lows along Florida’s East Coast have been in virgin territory over the past two decades, with record warm lows being busted every month of the year. The average low in West Palm Beach in August is 76; 77-78 in Miami; 79 in Fort Lauderdale and 75-76 in Naples. Yet there are many summer nights in which the temperature fails to drop below 80.

Fort Lauderdale’s low on Friday was 84, a new record warm low for the date — and the previous record of 83 was set just eight years ago in 2009. The low was 82 in West Palm Beach, tying the record set in 1993.

By the way, the normal low in West Palm Beach doesn’t sink below 70 until October 27.

As for AccuWeather’s autumn sneak peek, the commercial forecasting company is calling for “a few tropical hits” during the season for the southeastern U.S., with areas along the Gulf Coast and the Carolinas most vulnerable.

Forecasters also warned about flooding rains in the Florida panhandle and states as far north as Kentucky.

Elsewhere, they predicted California and the West Coast would have a warm and dry fall, with chilly temperatures in the Midwest and drought conditions in the Northern Plains. They said New England would have an unusually warm autumn.

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Forecast tracks for Invest 99L. (Credit: SFWMD)

TROPICS WATCH: The GFS has been picking on Florida over the past few days with suggestions on Friday that Invest 99L could turn into a major hurricane and threaten the Keys and Florida’s West Coast. Slight adjustments in track make all the difference in the world, and while Friday’s model runs kept the storm off-shore of Puerto Rico, Hispaniola and Cuba — a set-up that primes a system for a potential punch to Florida — Saturday’s runs plowed it into the Greater Antilles.

That can and often does tear up a storm thanks to some mountainous terrain, taking Florida off the hook.

Models are run every six to 12 hours, so we can expect many more flips and flops over the next week as 99L gets closer to the islands.

On the plus side, the European (ECMWF) is not terribly interested in 99L, but spins up the disturbance in the Caribbean (90L) and drives it into Mexico from the Bay of Campeche. The Euro has actually been very consistent with this forecast.

The Canadian has had its own brand of consistency with 99L, depicting a vigorous storm that rolls north well east of the Bahamas and off the U.S. East Coast.

It’s been clear the last few days that the Atlantic is still dominated by lots of dry air, and 99L has been struggling with these conditions. The National Hurricane Center slightly reduced chances of tropical development on Saturday, although forecasters continue to believe that chances are good for a tropical depression to form early next week.

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

10 day precip
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)

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.

 

Forecasters in Florida see possible shift to drier pattern

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UPDATE: The tropical wave in the Central Atlantic was designated Invest 92L by the National Hurricane Center. It was plotted at 5N 33.3W, about a thousand miles southwest of the Cape Verde Islands and 3,400 miles east-southeast of Miami. Early forecast models showed the system just clearing the northern coast of South America and moving northwest in the Caribbean. The eastern Caribbean is often a graveyard for Cape Verde storms, but early intensity models show 92L achieving and maintaining tropical storm strength through five days. (Image credit: SFWMD)

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Two areas of disturbed weather were upgraded Friday by the National Hurricane Center. (Credit: NHC)

Weather warning: A pattern shift may be dead ahead.

Forecasts for next week’s tropical weather are trending far enough west that Florida may be out of the picture for any significant rainfall. In fact, as we head toward July a typically drier pattern may be setting up, the National Weather Service says.

Normal July rainfall drops off in a major way from average June precipitation, falling from 8.3 inches to 5.76 inches in West Palm Beach and from 9.67 inches to 6.5 inches in Miami.

So climatology suggests that we may be moving toward a drier summer period.

Last year, July was uncommonly dry, with Palm Beach International Airport recording just 1.59 inches of rain and Miami, 4.11 inches.

That was particularly bad news since July 2016 was the hottest on record.

The Climate Prediction Center is noncommittal for July rainfall, predicting above-normal precipitation for the northern Gulf Coast while shrugging off most of the rest of the country. There’s a big question mark over the Florida peninsula, and rainfall totals will probably depend in part on how active the tropics will be next month.

As for the two systems on the National Hurricane Center map currently, both earned upgrades overnight. The Low that is progged to form over the Yucatan was given a 60 percent chance of tropical development by early next week, and the Atlantic wave that rolled off the coast of Africa on Monday was upgraded to 40 percent over five days.

The next two names on the Atlantic list are Bret and Cindy. And although the Central Atlantic wave appears to be getting better organized, the NHC track suggests it might crash-land into South America before it has a chance to cause any mischief in the Caribbean.

It is slightly disturbing, for non-meterological reasons, that the names for the 2017 hurricane season are recycled from 2005, although there were a number of retired names that year so instead of Katrina, there’s Katia; and instead of Rita there’s Rina; and instead of Wilma there’s Whitney.

These names were used in 2011 as well, and that season was no slouch with 19 named storms, seven hurricanes and four majors.

July was quite active that year with three tropical storms, and then things got crazy in August with seven named storms forming in the Atlantic, including Category 3 Hurricane Irene.

Fortunately, names are just names and have nothing to do with environmental conditions over any given year.

We hope.

Chances of tropical system in Gulf are increasing, Hurricane Center says

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National Hurricane Center forecasters got out their orange marker for the Yucatan Peninsula on Thursday, showing increased odds for tropical development. (Credit: NHC)

A tropical storm or depression is looking more likely in the Gulf of Mexico next week after the National Hurricane Center bumped up chances for development.

Forecasters said there’s a 50 percent chance that a low expected to spin up near the Yucatan Peninsula will become a tropical depression, or Tropical Storm Bret, by Tuesday.

NOAA’s GFS and the European model (ECMWF) are in agreement with development, and eventually take the system into Mexico, while the Canadian (CMC) and the Navy model (NAVGEM) push a deeper low up through the Central Gulf of Mexico toward the western Florida panhandle.

But since the GFS and ECMWF are the gold standards in weather forecasting, local National Weather Service are basing their longer-term forecasts on the western scenario, which will likely mean less rain for Florida’s East Coast next week.

The eastern Atlantic tropical wave, meanwhile, still has a 20 percent chance of developing by Tuesday, the NHC said. But it’s interesting to note that several other potent waves are emerging off the coast of Africa behind the one posted on the NHC forecast map — very early, indeed, for such a parade to begin.

However, wind shear analyses by the University of Wisconsin continue to show hostile conditions in the Central Atlantic, with shear ranging from 25-50 knots. Ditto for the western Caribbean, although conditions become a bit more marginal in the Gulf of Mexico, and shear is forecast to drop in the southwestern Gulf on Friday.

It’s also interesting to note that neither area of projected development has been designated an invest yet by the NHC, which means the full range of model maps is not yet available. For the western Caribbean, that could change later on Thursday or Friday, since storms seem to be boiling up with more frequency off the coast of Central America.

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OUT WITH DROUGHT: Florida’s wet June has really done a number on drought conditions that had built up over the dry spring. Thursday’s report by the U.S. Drought Monitor showed drought-free conditions in all of South Florida with Moderate Drought still in place in Central Florida from Tampa to Brevard County on the East Coast.

That could be wiped away next week if any of the tropical moisture from the Gulf makes its way into the Tampa area.

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SNEAK PEEK AT EARLY FALL: NOAA’s Climate Prediction Center released its 90-day forecasts Thursday, indicating above-normal temperatures across almost all of the U.S. through September. Forecasters hedged their bets on precipitation forecasts, indicating equal chances for above- or below-normal rainfall across most of the country with the exception of the northwestern Gulf coast, where abnormally high precipitation is forecast.

Normal rainfall is expected in South Florida through the end of June.

Wet June may bring some relief to parched Florida peninsula

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Storms that brought heavy rain to parts of Texas were moving into the Gulf of Mexico Monday. (Credit: NOAA)

As Florida broiled over the holiday weekend, the Gulf of Mexico was stormy, with rain stretching from the coast of South Texas northeast into the Florida panhandle.

The question is how much of this — if any — may be coming to the Florida peninsula later in the week.

Parts of Nueces County near Corpus Christi were reporting more than 4 inches of rain over a 12-hour period ending Monday morning. Cameron County to the south received more than 2 inches along the coast and an observer outside of Houston measured 3.60 inches, according to the Community collaborative Rain, Hail & Snow Network.

Much of this activity was spreading into the western Gulf of Mexico, and Escambia County (Pensacola) in Florida’s western panhandle had about a half-inch to an inch-and-a-half of precipitation.

The heavy rainfall was not going to translate, unfortunately, into a wet end of the week for Central and Southern parts of the Florida peninsula, according to the National Weather Service. But rain chances do increase statewide by Thursday and Friday.

Heaviest rainfall amounts, according to NOAA’s Weather Prediction Center, will be in the Jacksonville area, which is where it is least needed. Interior locations of South Florida may be in for a little more than an inch of rain through the weekend, while South Florida’s East Coast metro areas may see more in the quarter- to half-inch range, graphical forecasts suggest.

Even though there are apparently no soakers on the horizon for South Florida — or for the Keys — longer-term forecasts have the state in the soup through at least the third week of June, with above-normal rainfall projected.

Since June is the wettest month in South Florida, along with September, there’s reason to be optimistic that the upcoming month will deliver some relief to parched landscapes.

Most major reporting stations around the state show rainfall deficits for May, from the Keys into Central Florida, while North Florida has been maintaining a surplus.

Jacksonville has measured almost 7 inches of rain this month for a May surplus of 4.80 inches; Gainesville has a 2.33 inch surplus.

In Central Florida, Vero Beach and Fort Pierce boast surpluses of 1.69 inches and 0.71 of an inch as of Sunday. Sarasota is up 3.16 inches and Clearwater, 0.38.

In the panhandle, Tallahassee has a 2.53 inches surplus.

June precip

The Climate Prediction Center is forecasting above-normal precipitation in Florida and most of the eastern U.S. through at least the first three weeks of June. (Credit: NOAA/ CPC)

RECORD WATCH: In addition to Miami’s record high Sunday, Key West reported a second-straight record warm minimum temperature of 81, which tied the mark set in 1924.

Florida temperature records fall from Miami to Tampa

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More muggy nights are in the forecast for South Florida, and record warm temperatures are possible, according to forecasters. (Credit: NWS-Miami)

Temperature records — some that had stood for more than 70 years — fell up and down the Florida peninsula Wednesday as summer weather grabbed hold and appeared to settle in for the long run.

The only question was whether the heat and humidity would soon be accompanied by a return to the wet season, a critical issue since most areas continue to struggle with significant rainfall deficits.

Tampa sizzled under a record-breaking high of 98 degrees, shattering the old record of 96 set in 1995. In Sarasota, the high of 97 busted a 74-year-old high temperature record of 95 set in 1943.

Naples also broke a 74-year-old high temperature record with 95, beating the 1943 record of 94, and Fort Myers checked in with 96, 2 degrees hotter than the 2003 record of 94.

Florida’s East Coast, meanwhile, registered record warm minimum temperatures. Wednesday’s low in Miami was 80, which tied a record set just last year. The low in Melbourne was 78, busting the old record of 75 last set in 1980, while Vero Beach tied a record low with 75.

A few spots in inland Collier County reached the upper 90s, but most East Coast locations, including South Florida metro areas, were held to the mid- to upper-80s with brisk easterly winds off the Atlantic. West Palm Beach reported a gust of 29 mph, and gusts as high as 37 mph were measured in Broward and Miami-Dade counties.

The area of D3 Extreme Drought expanded to the East Coast this week, encompassing southern and central portions of Brevard County, according to an analysis released by the U.S. Drought Monitor on Thursday. Extreme Drought also expanded west, moving into almost all of Polk County and edging north toward Orlando.

Most of the rest of the Florida peninsula was dealing with D2 Severe Drought, but Palm Beach, Broward and Miami-Dade counties remained drought-free. Gulf Coast areas in the panhandle were also drought-free.

90 day temps
The U.S. may be in for an unusually hot summer if this long-range forecast from NOAA pans out. (Credit: CPC)

NOAA’s Climate Prediction Center released its long-range forecasts for May and for June, July and August on Thursday, showing very high probabilities of above average temperatures along the entire East Coast, from Florida to Maine, and west long the Gulf Coast into South Texas.

Above normal summer temperatures are forecast for most of the U.S., in fact, from the Great Lakes into the Southern Plains and Rocky Mountain States and west into California, Oregon and Washington.

No below average temperatures are forecast anywhere in the country this summer, although forecasters hedged their bets on the northern Central Plains, saying there are equal chances for above normal, below normal or normal temperatures.

FLORIDA RAINY SEASON: The National Weather Service is still anticipating a pattern change to wet season conditions next week. Forecasters in Miami said Thursday:

“The long-term period will start with a continued brisk east/southeast flow regime across the region, as hints of a more typically established wet season pattern become more apparent.

“Increasing low-level moisture and diurnal heating will lead to isolated to scattered showers and thunderstorms through the period. Daytime activity will likely be focused across the interior and Gulf Coast, with nighttime activity more focused across the East Coast and Atlantic waters.”