Florida braces for heavy rain, coastal flooding

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PM UPDATE: More than 5 inches of rain is possible in parts of South Florida over the next several days as a tropical system coming in from the southeastern Bahamas — previously tracked as Invest 95L by the National Hurricane Center — moves toward the Florida peninsula Thursday and Friday.  NHC forecasters were still giving a 10 percent chance of tropical development over the next five days if it can stay off the Florida coast. Either way, heavy rain is in the forecast for the Florida peninsula.

On top of that, the tropical wave in the Mid-Atlantic that has been tracked by the NHC, now designated 96L, was given a 70 percent chance of development by Monday.

Forecast models have been sending this system out to sea near the Bahamas, but the Wednesday night run of the legacy version of NOAA’s GFS — replaced in June by the latest upgrade — brings it near Florida’s East Coast.

The National Weather Service in Miami said late Wednesday: “Early Next Week: The mid and upper level trough remains situated over the eastern sea board of the United States with an extension into Florida expected. This will allow the wet pattern to continue which will require continued monitoring and attention.

“However, eyes are also on the tropics as the next area highlighted in NHC`s Tropical Weather Outlook may push westward from the Antilles. Obviously uncertainty is high this far out in the period, but this pattern will need to be monitored to see if the blocking trough remains over the region as any potential tropical features approach.

“This should serve as a clear reminder that August is here, knocking on our collective doors, and that the climatological peak of hurricane season approaches. This is an excellent time to ensure that hurricane action plans including supplies, preparations for family members/friends/pets/businesses, and important documents are reviewed and ready in case action becomes necessary.”

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(Image credits: Top, NHC; bottom: Early forecast models for Invest 96L via SFWMD)

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Street flooding

(Image credit: NWS-Miami)

ORIGINAL POST: The rugged land masses of Puerto Rico and Hispaniola, and high wind shear, took their toll on Invest 95L early this week as it limps toward the Bahamas. Nevertheless, the National Weather Service in Miami sent out a special weekend weather outlook to the media on Wednesday, warning of possible heavy rain and flooding from the system.

“Minor coastal flooding is also possible given a new moon and tide levels averaging a bit above predictions.” forecasters said. Tide levels are averaging .8 to .9 above normal, with a new moon on Friday, they said.

The forecast is for 2-3 inches with locally higher amounts starting on Friday and going into the weekend. East-Central Florida is expecting around an inch.

Jacksonville is looking for increased “nuisance flooding” due to the new moon, and possibly heavy rainfall over the weekend leading to minor flooding. Ditto for Florida’ West Coast, since the passage of 95L to the east should draw up moisture from the deep tropics and spread it over the entire peninsula.

Weather watchers are turning their attention to the tropical wave that’s about to enter the Mid-Atlantic. It hadn’t been designated 96L as of early Wednesday but that seemed to be just a matter of time, since forecasters at the National Hurricane Center bumped up development chances of the wave to 50 percent by Monday.

Forecast models generally show this storm heading out to sea east of the Florida peninsula, but it’s too soon to let your guard down, since arrival of the system in the vicinity of the U.S. Coast is still more than seven days away. This will likely be the topic of discussion for tropical weather buffs over the next few days since it’s our first real Cape Verde system, a long-tracking storm that has the potential to jump-start the meat-and-potatoes of the hurricane season.

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ALARM BELLS IN THE ARCTIC: Glaciers from Alaska to Antarctica are melting up to 100 times faster than previously thought, according to a new article in Scientific American.

A team of glaciologists from the National Snow and Ice Data Center in Boulder, Colo. are using technology that fishermen use to track their catches — a multibeam sonar instrument, which maps the topography of the glacier’s face from a distance.

They found they could determine the which parts of the glacier were melting by analyzing the shape of it over time. “When they combined that information with GPS data that tracked the glacier’s movement, they could chart the rate of meltwater flow,” the magazine says.

At the peak of the melting season in August, melting rates are higher below the water line where the glacier enters the ocean from land. That causes more ice to break off, which sort of unlocks the land-based ice and gives it a path to the water. “The glacier starts speeding up because it’s like removing a plug in front of the glacier,” says glaciologist Eric Rignot of the University of California, Irvine, and NASA’s Jet Propulsion Laboratory.

The article contains some dramatic time-lapse photos of water gushing from glaciers and the land-based ice flowing toward the sea.

It’s a timely look at glacier melt since, as July ended and August was beginning, record-setting high pressure was moving over Greenland, poised to jack up temperatures and speed up ice melt. Whatever comes off Alaska — and Greenland — contribute directly to sea level rise.

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Global temperature rise increases risk of armed conflict, study says

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High-end projected rainfall totals for South Florida through Thursday. (Image credit: NWS-Miami)

Almost 3 inches of rain socked the Upper Keys on Sunday, while coastal Miami-Dade County picked up more than 2 inches. Officially, Miami International Airport measured 2.43 inches.

In Central Florida, Orlando reported 1.79 inches, and west-central Florida — particularly northern Pinellas County — checked in with around 2 inches.

Rainfall totals dwindled as you went south in the Keys, with Marathon posting 0.47 of an inch and Key West checking in with just a trace of rain. Key West has a 1.82-inch precipitation shortfall in June through Sunday.

Up to 2 more inches of rain is expected in parts of South Florida — up to 3 inches in East-Central Florida.

Speaking of heavy rain, a new study by Georgia State University concludes that heavy early season rainfall increases the risk of mosquito-related disease such as West Nile Virus, dengue, chikungunya and Zika.

The study focuses on early season hurricanes, but we know in Florida you don’t necessarily need a tropical storm or hurricane to precipitate a long stretch of heavy rain.

Researchers said that heavy rain occurring on July 1 results in 70 percent fewer mosquito-related disease cases compared to an event that occurs on June 1.

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WHEN HOT-HEADS PREVAIL: A more disturbing study from Stanford University claims the risk of armed conflict rises “dramatically” during periods of climate warming. Climate has influenced up to 20 percent of armed conflicts over the last century, researchers said.

A Stanford news release explains: “In a scenario with 4 degrees Celsius of warming (approximately the path we’re on if societies do not substantially reduce emissions of heat-trapping gases), the influence of climate on conflicts would increase more than five times, leaping to a 26 percent chance of a substantial increase in conflict risk.

“Even in a scenario of 2 degrees Celsius of warming beyond preindustrial levels – the stated goal of the Paris Climate Agreement­ – the influence of climate on conflicts would more than double, rising to a 13 percent chance.”

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Full Disk - Clean Longwave Window - IR

IMPRESSIVE ‘WAVE TRAIN’ FOR MID-JUNE: Some of the tropical waves crossing the Atlantic this month have looked pretty healthy, as Monday’s satellite image shows. Luckily, wind shear to the north and in the Caribbean should zap any chances of development. The National Hurricane Center’s Tropical Weather Outlook map predicts no storms in either the Atlantic or eastern Pacific through at least Friday. (Image credit: NOAA)

Pretty cool: Florida temps plunge into 40s and 50s

Tuesday morning’s cool and crisp temperatures offered a refreshing change of pace around the Florida peninsula, especially as we head into the warm weather months of steamy temps without a break.

It was in the low 60s along much of the South Florida coast, with a few upper 50s west of Lake Okeechobee and also north of the Fort Myers area.

A Weather Underground observer reported 52 degrees north of Avon Park, and northeast of Tampa it was 51 degrees.

Also on the West Coast, it was in the mid- to upper-40s from Spring Hill north to Cross City. In North Florida, it was 44 in Lake City.

Panhandle temps were mostly in the 40s except 50s were spread across the immediate Gulf Coast.

The cool weather didn’t seem to make it down to the Keys, where it was in the mid-70s.

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Friday SPC

(Image credit: NOAA/ SPC)

WEEK-ENDING WEATHER: The next cold front rolls through Friday, and for now the Storm Prediction Center has taken South Florida off the severe weather map. The rest of the peninsula, though, from Lake Okeechobee north to the Georgia state line and west to around near Tallahassee, was under a 15 percent chance for severe weather on Friday.

That designation could continue to change, though, and forecasters in Miami said Tuesday morning: “It is still early to describe details about timing, impacts and duration of the potential severe weather.”

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ULTIMATE WEATHER WINDOW: Weather forecasting has improved dramatically over the past decades and continues to get better. But there’s a limit to how far out weather can be predicted, a new study by Penn State concludes.

“The obvious question that has been raised from the very beginning of our whole field is, what’s the ultimate limit at which we can predict day-to-day weather in the future,” said Fuqing Zhang, professor of meteorology and atmospheric science and director of the Center for Advanced Data Assimilation and Predictability Techniques at Penn State. “We believe we have found that limit and on average, that it’s about two weeks.”

A “predictability limit” for weather forecasting was first proposed in the 1960s by Edward Lorenz, a Massachusetts Institute of Technology mathematician and meteorologist. He theorized that weather can’t be predicted beyon a certain point “in principle.”

Zhang’s conclusion about the two-week window is “remarkably closes to Lorenz’s estimate,” he said.

Researchers used the most reliable forecast models to predict weather under “near picture-perfect” initial conditions. Even then, predictions were reasonably accurate up to about two weeks.

“We have made significant advances in weather forecasting for the past few decades, and we’re able to predict weather five days in advance with high confidence now,” Zhang said. “If in the future we can predict additional days with high confidence, that would have a huge economic and social benefit.”

After slight cool-down, more record temps expected in Florida by mid-week

NFL storms

Parts of the Central Florida panhandle were under a Tornado Watch Sunday morning as a cold front approached. North Florida expected strong storms, but the squall line was forecast to weaken Sunday night into Monday as the front associated with the system slides down the peninsula. (Image credit: NWS-Jacksonville)

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TORRID TEMPS IN TUNDRA: Canada’s Central Yukon Territory is the warmest its been in 13,600 years, researchers at the University of Toronto Mississauga have concluded in a new study.

Paleoclimatologists, who use radiocabon dating preserved in permafrost, along with other methods, were able to reconstruct summer temperatures over the last 13,600 years. They found that temperatures are nearly 2 degrees Celsius warmer than any previous summers during the Holocene period.

“We’re seeing the evidence right now that climate warming is destabilizing permafrost in northern Canada and releasing greenhouse gases,” said lead author Trevor Porter. “This is potentially the new normal and, if it accelerates in the near future, it threatens to further amplify global climate change.”

In March, the temperature soared to an unprecedented 71 degrees in Yohin Lake in Canada’s Northwest Territories and 76 in Tofino, British Columbia. Temperatures in the Arctic have been increasing at more than twice the rate of increases in the continental U.S., experts say.

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MORE RECORD WARMTH FOR FLORIDA: Overnight lows could run up to 10 degrees above average this week as an unusually strong ridge of high pressure builds over the state, forecasters said Sunday.

For perspective, the normal low this time of the year in Miami is 68; the normal high is 83.

After a slight cool-down statewide on Tuesday and Wednesday as the cold front clears the peninsula, highs will pop back to “significantly” above normal by mid-week, the National Weather Service said.

A round of record warm lows occurred on Saturday. Here’s the rundown:

  • Fort Pierce tied a record warm low with 74 degrees. The city hasn’t seen an April 13 low that warm in 71 years — the record was originally set in 1948.
  • Marathon set a new record warm low with a balmy 81 — easily beating the old record of 79 set in 2015.
  • The low in Fort Lauderdale was 77, which tied a record warm low set in 2015.
  • Daytona Beach tied a record warm low with 72, a mark originally set in 1991.
  • Melbourne tied a record warm low with 73, matching the record set in 2015.
  • The low was also 73 in Vero Beach, tying a record set in 1991.
  • Sanford broke a record warm low with 72. The old record was 71 set in 2001.
  • Jacksonville’s low of 71 beat the previous record warm minimum of 69 degrees set in 2015.
  • Gainesville’s low of 71 smashed the old record, set in 1974, by 3 degrees.

40 mph wind gusts possible; Marathon ties record high

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Gusty winds will pound Florida’s East Coast, from Jacksonville all the way down into South Florida, on Wednesday. (Image credit: NWS-Jacksonville)

Winds could gust as high as 40 mph along Florida’s East Coast Wednesday and Thursday, the National Weather Service said.

Boating conditions could be dangerous with an upper level low setting up just off the northern Bahamas. That will create a tight pressure gradient between the low and high pressure building to the northwest.

Winds will start to diminish on Friday, forecasters said, but Friday will still be breezy.

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CLIMATE CHANGE DELAYED? The Atlantic ocean current known as the Atlantic Meridional Overturning Circulation (AMOC) is slowing down — and it could have major implications for the U.S. East Coast as well as Europe. But not, perhaps, for hundreds of years.

Ultimately, much warmer temperatures may result along the East Coast, leading to stronger hurricanes and harming fisheries. Meanwhile, temperatures could plunge in Europe, the new study the Earth Institute at Columbia University says.

Researchers determined that the current weakened 400 years before a major cold era 13,000 years ago. It then began strengthening 400 prior to a warming trend 11,000 years ago.

“Our reconstructions indicate that there are clear climate precursors provided by the ocean state — like warning signs, so to speak,” said Francesco Muschitiello, the lead author of the study.

Researchers said the lag time of 400 years between the slow-down and climate change was “two or three times greater” than expected. They said evidence suggests that the current weakening began 150 years ago.

Co-author William D’Andrea said that “if the AMOC were to weaken to the degree it did back then, it could take hundreds of years for major climate changes to actually manifest.”

Muschitiello adds: “It is clear that there are some precursors in the ocean, so we should be watching the ocean. The mere fact that AMOC has been slowing down, that should be a concern based on what we have found.”

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First tornado warning

FIRST ALERT: Monday was the 71st anniversary of the first tornado warning issued in the U.S. The alarm was sounded at Tinker Air force Base in Oklahoma on March 25, 1948. Another tornado had slammed the base five days earlier. (Image credit: NWS-Key West)

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Marathon record high

RECORD WATCH: Monday’s high in Marathon was 87, which tied a record for the date. It was previously set in 2005. (Image credit: NWS-Key West)

Tuesday cold front won’t pack much of a punch, forecasters say

CFL expected rainfall
Only light rain is forecast with the arrival of next week’s cold front. Click on image for link to larger original. (Image credit: NWS-Melbourne)

A cold front on Tuesday is expected to push temperatures down slightly around the peninsula — and maybe deliver a few sprinkles.

Lows are forecast to dip into the upper 40s in North Florida and the panhandle, the mid- to upper-50s in Central Florida, and the upper 50s to low 60s in South Florida.

“Rain chances for South Florida with this frontal passage are not as high as what we saw last week,” National Weather Service forecasters said their discussion Sunday.

Precipitation probabilities range from 40-50 percent in Central Florida and 20-30 percent in South Florida.

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TROPICAL TROUBLE IN ATLANTIC: A rare tropical storm formed Sunday in the South Atlantic, Weather Underground reported.

Tropical Storm Iba was 600 miles northeast of Rio de Janeiro, Brazil with winds of 40 mph and it was moving toward the southeast, away from land. Winds could top out at 50 mph, Director of Meteorology Jeff Masters said.

It was “likely to slowly weaken by mid-week, never attaining hurricane status,” he said.

Iba is only the ninth tropical or subtropical system in the South Atlantic to get a name.

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MICHAEL UNDER THE MICROSCOPE: The University of Alabama is conducting a study on the impact of Hurricane Michael, the strongest storm ever to hit the Florida panhandle. Participants are being asked to take a 20 minute survey and may also be asked to do brief interviews or participate in focus groups.

Researchers are trying to determine how hurricane warnings were utilized during the storm in order to fine tune future hurricane warning messages.

Michael ripped through the Gulf of Mexico and intensified rapidly, making landfall on the Florida panhandle on October 10 with sustained winds of 155 mph,. That’s just under Category 5 strength. At least 45 deaths were reported in Georgia, the Carolinas and Virginia.

The information provided by participants will remain confidential.

Stormy week coming into focus as another cold front stalls over peninsula

The first significant rainfall of the month may be headed for Central and South Florida next week, the National Weather Service says.

Six and seven-day forecasts are subject to change, but forecast models are showing strong storms forming along a front that stalls over the southern peninsula early next week. NOAA’s Weather Prediction Center is projecting — for now — as much as 2-3 inches of rain for Florida East Coast, from the East-Central peninsula down to South Florida. The forecast will undoubtedly evolve over the next several days.

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Projected rainfall from Monday through Wednesday. (Image credit: NOAA/ WPC)

Here’s what National Weather Service forecasters said on Wednesday:

Miami: “Both global models hint at the possibility for cyclogenesis in our vicinity. At this time, agreement is poor in regards to timing and overall location. The most recent ECMWF run depicts more of a direct impact for South Florida while the GFS keeps much of the disturbance to the south before amplifying over the western Atlantic.”

Key West: “For Sunday through Tuesday, forecast guidance continues to squash the subtropical ridge southward into the Caribbean as a longwave trough is carved out over the eastern states. This allows the weak front to slide down across South Florida and the Keys by Monday into Tuesday, when it may interact with a disturbance riding along the subtropical jet. The details remain murky at this time, but it appears that a period of wetter than normal weather is in store for early next week.”

Melbourne: Forecasters are calling for a 60-70 percent chance of rain on Tuesday, but they add: “Further adjustments (upward?) are quite likely leading up to the event.”

Tampa: “Since we are talking about days 6 and 7, overall confidence in any one solution is low. The ECMWF has a large area of rather significant rainfall moving across the Florida peninsula as low pressure moves eastward across the central Gulf. The GFS, meanwhile, has a more suppressed solution as a deeper upper-level trough digs into the central Gulf pushing the frontal boundary to our southeast. Run to run consistency is better in the ECMWF than the GFS so will favor the wetter solution showing showers and storms returning for Monday and continuing through the day Tuesday.”

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RECORD WATCH: Marathon reported a record warm low on Tuesday, 77 degrees. It broke the previous mark for March 12 of 74, set in 2016.

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SKY HIGH HAZARD: We have enough to worry about with air travel, but now another potential problem has been identified: bombardment by neutrons.

A survey by Spaceweather.com and Earth to Sky Calculus detected neutrons on board flights during a five-continent survey from December 2018 to February 2019. Radiation sensors were used during 83 flight hours at 30,000 feet.

“The results were eye-opening,” science writer Tony Phillips noted in an article posted Tuesday. The amount of cosmic radiation was “about the same as 23 panoramic dental x-rays or two and a half chest X-rays. Moreover, 41 percent of the dose came in the form of neutrons. This confirms that cosmic-ray neutrons are abundant at aviation altitudes and must be considered in any discussion of ‘Rads on a Plane.'”

Phillips said the study “focuses on neutrons, a more potent type of radiation from deep space. Studies show that neutrons can be ten times more effective at causing biological damage compared to X-rays and gamma-rays in the same energy range. Neutrons are so effective, they are used for cancer therapy, killing tumors better than other forms of radiation.”

Check out the full story for more information and analysis.