Severe weather possible before weekend cold front arrives

Severe storm risk

(Image credit: NWS-Miami)

More than an inch of rain soaked the Cape Coral area of Southwest Florida overnight Wednesday into Thursday morning, and more was on the way for the first part of the weekend along with the potential for some severe weather in parts of South Florida.

NOAA’s Storm Prediction Center put much of South Florida at a Level 2 risk — forecasters call it a “Slight Risk” — Friday night through Sunday morning with the bulk of the storms occurring Friday night and Saturday.

For Saturday, the SPC has South Florida at a Slight Risk from just south of Naples over to Boca Raton on the East Coast, down to the peninsula’s southern tip.  A slice of Level 1 or “Marginal Risk runs from around Fort Myers up through West Palm Beach. Central Florida is expecting thunderstorms.

“The main hazards with these storms look to be gusty winds, small hail, minor localized flooding, and funnel clouds,” National Weather Service forecasters in Miami said. “Given the instability and shear, along with the presence of the jet, a brief tornado can’t be entirely ruled out, though the most prime location for that looks to be across the far southern portion of the peninsula.”

Sunday is expected to be clear and much cooler, with highs only around 70 in Miami, headed for an overnight low of 55; 67 in Orlando going down to a Monday morning low of 46; and 66 in Tampa heading for a low of 48.

Come to think of it, that’s not bad football weather. But expect to see lots of jackets and sweatshirts at Hard Rock Stadium in Miami on Super Bowl Sunday with game time temperatures slipping into the 60s along with wind gusts of up to 23 mph, according to the National Weather Service.

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RAINFALL REPORT: Observers for the rainfall network CoCoRaHS reported up to 1.26 inches of rain in Cape Coral, from late Wednesday through early Thursday morning. Glades and Hendry counties reported up to 1.23 inches; and Sarasota County had just under an inch.

An observer near Pahokee in Palm Beach County reported 1.10 inches, while coastal areas had closer to a quarter of an inch as a weak cold front rolled down the peninsula Wednesday night.

Northeastern Miami-Dade picked up as much as 0.81 of an inch, and around a half-inch fell on the Treasure Coast.

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Severe Weather Awareness hurricanes

AROUND THE CORNER AND DOWN THE STREET: Do we need a reminder? Apparently so, as Thursday is the day to focus on hurricanes in Florida as part of Severe Weather Awareness Week. Just in case you’re keeping score at home, there are 121 shopping days until the start of the 2020 hurricane season on June 1. (Image credit: NOAA)

Gusty winds hammer Keys, Florida’s East Coast

Keys wind gusts

Winds were gusting up to 39 mph in the Keys on Thursday due to a tight pressure gradient between high pressure to the north and low pressure to the south. Windy weather was in the forecast through Sunday. (Image credit: NWS-Key West)

Top wind gusts along South Florida’s East Coast (and inland) as of Friday morning: Fowey Rocks, Biscayne Bay, 39 mph; Sunrise, 38 mph; Tamiami Executive Airport, Kendall, 38 mph; Fort Lauderdale-Hollywood International Aiprort, 37 mph; Miami International Airport, 36 mph; Palm Beach International Airport, 35 mph; Immokalee, 35 mph;

East-Central: Melbourne, 32 mph; and Fort Pierce, 31 mph. Winds were calmer on Florida’s West Coast and in North Florida.

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MORE ON 2019: Annual average temperatures in East-Central Florida for each year since 2015 have been among the top 10 warmest on record for cities from Daytona Beach to Fort Pierce, the National Weather Service in Melbourne said in a report posted Thursday.

“Extreme warmth [occurred] at times, especially into February and the fall season,” meteorologists said. “Most notably, Vero Beach had their warmest September and October on record. It was also the warmest October on record for Daytona Beach and Orlando.”

Check out the full report for complete details.

Separately, Weather Underground discussed a NOAA report that said Florida had its second-hottest year and the U.S. had its second-wettest year on record in 2019.

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PONDERING THE PACIFIC: ENSO neutral conditions are expected in the Tropical Pacific through spring and perhaps through summer as well, NOAA’s Climate Prediction Center said in an analysis released Thursday.

The gave neutral conditions — neither El Niño, abnormally warm waters, nor La Niña, abnormally cool waters — a 60 percent chance of lasting through spring and a 50 percent chance of lasting through summer. Neutral conditions currently prevail.

It’s an important forecast in terms of the 2020 hurricane season. Under El Niño, tropical activity in the Atlantic is suppressed due to increased upper-level wind shear, while La Niña is usually accompanied by above-normal hurricane activity in the Atlantic.

When El Niño conditions ended last summer, hurricane activity spiked, producing such storms as the deadly Hurricane Dorian.

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FLORIDA DROUGHT UPDATE: Drought conditions faded throughout Florida after a wet December, the U.S. Drought Monitor said Thursday. Moderate Drought lingered, though, in the Central Panhandle and Moderate Drought was reduced to Abnormally Dry conditions in the Everglades.

40 degree temperature drop forecast this weekend for parts of peninsula

ECFL highs

(Image credit: NWS-Melbourne)

One of the challenges of living in Florida is dealing with its yo-yo temperatures during the winter. For example, most of the peninsula is forecast to be in the 80s today — with mid-80s over the interior all the way up into the Orlando area — but then plunge with Sunday’s cold front.

In Orlando today’s forecast high is 85, and Sunday morning’s forecast low is 47; Monday morning’s is 43. That’s a 40-degree temperature drop and any way you slice it or dice it, it takes some adjustment.

Put the thermostat on AC one day; flip it over to heat the next.

Fortunately, once this initial cold snap is over early next week it looks like we’ll be settling into a little longer pattern of temperatures that are close to average for this time of the year, according to the National Weather Service.

Friday’s run of the GFS forecast model suggests another period of much-above normal temperatures toward the middle of the month.

Normal highs in Miami edged down to their lowest of the year on Tuesday, from 77 to 76. That’s the normal high until January 23, when they begin the long march back up into the 80s and beyond. It’s a similar story around the state — the normal high in West Palm Beach bottoms out at 74 on Sunday, January 6 and begins bouncing back on January 18.

Orlando’s normal high is 71 and remains there until January 24, when it edges up to 72.

Tampa’s normal high of 70 begins climbing on January 28, when it’s 71.

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Rainfall totals for Hurricane Florence were devastating to parts of the Carolinas. (Image credit: National Weather Service)

HURRICANE RESEARCH: Climate change was responsible for the epic amount of rainfall generated by Hurricane Florence, the 2018 storm that swamped parts of North Carolina with more than 35 inches of rain, a new study by Sony Brook University in New York concludes.

Prior to Florence’s landfall in September, a university research team projected that rainfall amounts would be up to 50 percent higher due to warmer water temperatures.

“Rainfall amounts over large ranges were significantly increased,” the university said in a news release Thursday. The size of the storm also expanded.

“This post-storm modeling around climate change illustrates that the impact of climate change on storms is here now and is not something only projected for our future,” said Kevin Reed, assistant professor in the School of Marine and Atmospheric Sciences at Stony Brook.

Reed explained the storm modeling techniques his team used in this YouTube video.

The research was published in Science Advances.

Colorado State unveils first look at 2020 hurricane season

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The 2019 hurricane season was a busy one, but it mostly spared Florida. Will we be as lucky in 2020? (Image credit: NOAA/ NHC/ NASA)

LOOKING AHEAD TO 2020: Another active Atlantic hurricane season may be on the horizon for the Atlantic Basin in 2020, Colorado State University researchers said in an analysis released Thursday. But the El Niño forecast for next summer and fall is a huge unknown, and could swing next year’s tropical storm season in the other direction.

The projection, by CSU’s Philip Klotzbach, Michael Bell and Jhordanne Jones, calls for a 45 percent chance of total Accumulated Cyclone Energy (ACE — a measure of the strength and duration of all storms combined) of between 130-170. They put chances of an 80 ACE season at 45 percent; and a 50 ACE season at 10 percent.

A 170 ACE season typically has 14-17 named storms, nine to 11 hurricanes, and four or five major hurricanes. At the bottom end, an 80 ACE season has eight to 11 named storms, three to five hurricanes and one or two major hurricanes.

The 2019 season had an ACE of 130, with 18 named storms. A near-normal season has an ACE less than 103, according to NOAA. The average season has 12 named storms.

In addition to the presence of lack of an El Niño in the Pacific — above normal water temperatures that create wind shear in the Atlantic — forecasters also keep a close eye on the Atlantic Multi-Decadal Oscillation, which affects sea surface temperatures in the North Atlantic.

“The Atlantic had three quiet hurricane seasons from 2013-2015, followed by a slightly above-average season in 2016, near record-breaking levels of activity in 2017 and slightly above-average seasons in 2018 and 2019,” they said. “Four above-average seasons lends confidence that the AMO remains in a positive phase, although the far North Atlantic has generally been characterized by below-average sea surface temperatures (SSTs).

“Another big question for 2020 is how El Niño-Southern Oscillation (ENSO) will trend over the next few months. As is typically the case at this time of year, there is considerable model disagreement as to what the phase of ENSO will look like for the summer and fall of 2020.”

The December analysis is considered a “qualitative discussion” by CSU and only suggests typical season numbers based on ACE. The first “formal forecast” will be released on April 2.

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RAINFALL REPORT: More than 4 inches of rain soaked the Palm City area in northeastern Martin County during a 24-hour period from Wednesday morning to Thursday morning, according to the citizen observation network, CoCoRaHS.

Totals of 2-3 inches were common in the Stuart area and in southern Saint Lucie County.

A couple of observers to the south in eastern Palm Beach County and northeastern Broward County measured around 2 inches, but most areas picked up a third- to around a half-inch. And 1-2 inches fell in the Middle Keys.

Southwest Florida was a little drier and only a few hundredths of an inch fell in the Tampa area.

Still, it was the most significant rainfall of the month so far, and more was in the forecast as the frontal boundary that skidded into South Florida makes a U-turn and heads back to the north.

Drier air moves in for the end of the weekend but then another front on Tuesday increases rain chances again, according to the National Weather Service.

RECORD WATCH: Fort Myers set a record high Wednesday with 87 degrees. That beat the old record high for the date of 86 set in 1961. Miami tied a record high with 85, last set in 2012.

Sarasota ties record high; coldest temps since March arrive next week

RECORD WATCH: Sarasota tied a record high Friday with 86, matching the mark originally set in 1990. It was also 86 in Fort Myers, but that was shy of the record for the date, 89 degrees set in 1990.

In South Florida, there were a few mid-80s in inland Collier County and an observer in Weston, Broward County, reported a high of 86 to the National Weather Service in Miami.

It was officially 85 in Naples, well off the record of 89 set in 1990.

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Tuesday highs WCFL

(Image credit: NWS-TampaBay)

COLD FRONT UPDATE: The National Weather Service was ratcheting down projected lows for Tuesday morning following the passage of the strongest cold front of the season so far.

Miami, 55 (which would be the coldest temperature since March 6); West Palm Beach: 48 (would be the coldest since January 29); Orlando, 43 (would be coldest since March 7); Tampa, 45 (coldest since March 6); Jacksonville, 39 (a temperature matched as recently as Monday, November 26); and Tallahassee, 35 (the city reached 22 degrees on November 13).

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two_atl_5d0

(Image credit: NHC)

TEMPUS TERMINUS: The 2019 hurricane season officially ends today — although it’s not impossible to get a storm in December. The final numbers were 18 named storms, six hurricanes and three majors. There were also two depressions that didn’t earn named status.

For a more detailed analysis of the season, see Wednesday’s Florida Weather Watch post.

NOAA assesses memorable 2019 hurricane season

It was the fourth consecutive above normal year — only the second such stretch in hurricane history

IMAGE-Satellite-Atlantic hurricanes - September 2019 - From Left to Right - Fernand - Dorian - Gabrielle - Landscape

The satellite image from September 3 showed three storms in the Atlantic. Activity ramped up suddenly in late August and September, and the frantic pace continued into October. (Image credit: NOAA)

NOAA released its 2019 hurricane season wrap on Tuesday, noting that this was the fourth season in a row with above normal Atlantic activity. In hurricane history dating back to 1851, there has only been one other such stretch, from 1998-2001.

“Also this year, five tropical cyclones formed in the Gulf of Mexico, which ties a record with 2003 and 1957 for the most storms to form in that region,” NOAA said. “Of those, three — Barry, Imelda and Nestor — made landfall in the U.S.”

There were three major hurricanes this season — Dorian, Humberto and Lorenzo. Dorian, which tied three other hurricanes — the 1935 Labor Day Hurricane, 1988’s Hurricane Gilbert and 2005’s Hurricane Wilma — for the second-strongest winds ever recorded in the Atlantic, made for an especially tense Labor Day Weekend in Florida.

The monster storm, with sustained winds of 185 mph, was forecast to plow into the Florida peninsula around Palm Beach County at one point, but then Dorian’s predicted landfall began edging to the north. It ultimately stalled over Grand Bahama and devastated Marsh Harbor on Great Abaco Island.

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(Image credit: NHC)

This was the NHC forecast that slapped Florida residents on the evening of Thursday, August 29, as the storm began undergoing rapid intensification. The forecast was for a direct hit on the South-Central Florida coastline. By Saturday morning, forecast models began suggesting a turn to the north.

Residents were glued to forecast models, which are issued every six hours. At one point, the HMON had a wild, heart-thumping hurricane off the coast of Miami with a central pressure of 919 mb — for perspective, Andrew was 922 at landfall.

After pounding the Bahamas, and scaring the wits out of Florida’s East Coast, Dorian finally made landfall in Cape Hatteras, North Carolina, on September 6 as a Category 1 hurricane with 90 mph winds.

It was one of four storms that made landfall in the U.S. during the 2019 season, along with Hurricane Barry, Tropical Storm Imelda (another huge rainmaker that brought catastrophic flooding to Texas), and Tropical Storm Nestor.

“This season’s activity ramped up in mid-August during the normal peak of the season, as we predicted,” said Gerry Bell, lead seasonal hurricane forecaster at NOAA’s Climate Prediction Center.

“The above-normal activity is consistent with the ongoing high-activity era, driven largely by the Atlantic Multidecadal Oscillation, which entered a warm phase in 1995. Conditions that favored more, stronger, and longer-lasting storms this year included a stronger West African monsoon, warmer Atlantic waters, and weak vertical wind shear across the western Atlantic and Gulf of Mexico.”

An average season has 12 named storms, six hurricanes, and three majors.

How did the preseason forecasters do this year? NOAA predicted nine to 15 named storms in its May outlook, with four-to-eight hurricanes and two-to-four majors. It drastically upped its forecast in August, which raised some eyebrows since only two named storms had formed through the middle of the month.

But when the Climate Prediction Center announced that El Niño conditions in the Pacific had ended, NOAA forecasters concluded that the peak of the season would kick into high gear, and they were right.

Colorado State University remained fairly conservative in its forecasts, calling for 13 named storms in April; 14 named storms in June and 14 in August.

Ultimately, the 2019 season beat every single forecaster with 18 named storms — the closest April forecast was from North Carolina State University, which had predicted up to 16 named storms. NOAA predicted up to 17 named storms, but not until its August forecast.

Looking ahead, Colorado State University will release its first 2020 outlook in two weeks, on December 12. The CSU team discusses probable conditions and offers a range of possibilities in that initial outlook, rather than firm numbers.

The UK’s Tropical Storm Risk will also release its initial 2020 forecast that week.

So long, Sebastien; holiday week warm-up begins on Tuesday

two_atl_5d0

(Image credit: NHC)

CLEAR SAILING: Saturday marks the official end of the 2019 hurricane season, and it looks like it will go out on a quiet note. The National Hurricane Center will issue its final Tropical Weather Outlook on Saturday; outlooks are issued off-season only as necessary.

Sebastien was still packing 60 mph winds near the Azores on Sunday night, but the NHC said it had lost its tropical characteristics. The agency issued its final advisory late Sunday night.

The storm brought gusty winds and rain to the Azores, but didn’t cause any major damage, according to Azorestoday.com.

The remnants of the storm were expected to sweep into Ireland and the United Kingdom with rain and gale-force winds on Tuesday and Wednesday.

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SWEATER WEATHER: It was a chilly Monday morning in Florida with mid- to upper-30s in the panhandle and North Florida; 40s in the Orlando area; low 50s in Central Florida and parts of interior South Florida; and upper 50s to near 60 in coastal South Florida. The Keys were mostly in the upper 60s.

Interestingly, there were no bitter cold air anywhere in the U.S., and the temperature in the panhandle inland from the coast was almost the same as temps in the Mid-Atlantic and in New England, where 30s prevailed.

It’s an indication that this cool-snap will be relatively brief, with temperatures climbing back to near 80 degrees around South and Central Florida by Tuesday and Wednesday. And all of Thanksgiving weekend looks pretty nice, according to the National Weather Service, with highs around 80 and lows in the 60s.

BEFORE THE FRONT ROLLED THROUGH: Marathon once again had the state’s high on Sunday with 85, and Miami International wasn’t far behind with 84. (The record high for the date in Miami was 88, set in 2014.)

RAINFALL REPORT: Sunday’s front dropped up to a third of an inch of rain in parts of South Florida, except that a CoCoRaHS observer in Glades County near Palmdale reported 0.60 of an inch.

Observers in Miami-Dade County reported around a tenth of an inch, but Miami International Airport officially checked in with 0.16 of an inch.