At last, expect break from heat this weekend
West Palm Beach still in running for its warmest February on record.
Tumbling temperatures are expected in South Florida late this week as a global atmospheric shift allows arctic air to edge closer to the tropics.
The cooler weather, which should reach Palm Beach County overnight Friday into early Saturday, will be an abrupt change in the unusual heat that has this month in the running for the warmest February on record in West Palm Beach.
Temperatures in the low to mid-70s with overnights dipping into the 50s are forecast for the weekend and into Monday, with low chances of rain.
“We’ve been consistently running 5 to 10 degrees above normal, so the cooler temperatures are pretty relative,” said Arlena Moses, a meteorologist with the National Weather Service in Miami. “For us, the setup for significant cold air is not expected, but my guess is this won’t be our last cold front.”
The average daytime high for this time of year is 78 degrees as measured at Palm Beach International Airport. The average overnight low is 61.
On Monday, the high in West Palm Beach reached 82 degrees, with a low of 70. The heat could turn up to 85 on Thursday ahead of the front.
“It’s going to seem a lot cooler for everyone,” Moses said about the weekend forecast.
A persistent swirl of high pressure that clung to Florida for much of February and was the cause of the winter warmth will begin to break down closer to the weekend. At the same time, a new weather pattern that also roared to life during the winter of 2009-10 will get established over eastern Canada and Greenland.
A western shift in the so-called
“Greenland block” — a particularly strong area of high pressure — will help funnel northern air toward Florida as the polar jet stream reacts with a severe plunge south.
In January 2010, the Greenland block made for a spectacular cold spell in South Florida, with a high temperature Jan. 10 of that year reaching just 50 degrees and the low falling to 32.
“It doesn’t look like the cold air will get into Florida with that kind of gusto this time,” said Evan Duffey, an AccuWeather meteorologist. “But it’s worth keeping an eye on.”
For Mid-Atlantic states, the high pressure over Greenland could make for a potent winter storm late in the week if an area of low pressure moving east gets slowed by the Greenland block.
National Weather Service meteorologists in Boston are forecasting the potential for a “significant coastal storm” to lash southern New England with strong winds Friday into Saturday. Meteorologists in the Washington, D.C., area are warning that gusty winds and a rain-saturated ground could lead to isolated tree damage.
Forecasts past five to seven days can be notoriously tricky, and models often get it wrong, so there’s that caveat with the coming cool front.
But senior AccuWeather meteorologist Dan Kottlowski was confident Monday that a shot of cold air will reach South Florida this weekend. Another cool front during the second weekend in March also is possible, he said.
“It doesn’t mean we’re going to get super cold,” Kottlowski said. “But it does mean the above-normal temps we’ve been experiencing the past couple of weeks will take a hiatus.”
As of Monday, West Palm Beach, Fort Lauderdale and Miami were all experiencing their warmest February on record, according to the Southeast Regional Climate Center. In West Palm Beach, the average temperature this month was 75.2 degrees — nearly 8 degrees above normal.
Florida Climatologist David Zierden worries the warm February has coaxed grasses and pastures into a spring growth spurt.
“A March freeze would kill new growth and set the clock back many weeks,” he said in a social media post Monday. “Drove the state on Saturday and pastures from Orlando north to the Panhandle were a vibrant green.”