(Trends Wide) — A lobe of frigid air will sink deep into the US, bringing sub-zero temperatures to southern Florida, while severe thunderstorms sweep across the Mid-Atlantic and heavy snow hit parts of the Northeast.
March started out fairly mild in the eastern US and even downright warm in the southeast. Many places set all-time highs in the ’70s and ’80s as recently as this past Sunday and Monday. The heat has caused many trees, flowers and crops to already be in bloom.
But the intense storm will bring plummeting temperatures and frigid air from Canada to the Gulf Coast. Locations from Louisiana to South Carolina and south to Florida expect frost Saturday night through Sunday morning. Many of these places will experience a severe freeze, with several hours below -2 degrees.
Low temperatures for a significant period across much of the Deep South will threaten vulnerable vegetation.
“Freezing conditions will kill crops, other sensitive vegetation and possibly damage unprotected outdoor plumbing,” the National Weather Service (NWS) in Birmingham, Alabama said.
More than 30 record lows are possible Sunday morning from Louisiana to central Florida and as far north as the Mid-Atlantic. Temperatures will be in the teens for the Tennessee Valley in the Mid-Atlantic and Northeast, but no freeze advisories are being issued for these locations because the growing season hasn’t started.
Flood watches are in effect Friday through Saturday mornings in north Florida and south Georgia, in part because the ground was already saturated from the rainy days. Rainfall of 76 to 152 mm is forecast in this same area from Friday to Saturday morning.
An extended tornado watch is in effect until 11 a.m. ET Saturday for 26 counties in Florida and includes Tampa, Daytona Beach and Orlando. Nine counties in southeastern Georgia are also under surveillance.
Mid-Atlantic prepares for severe storms
Strong thunderstorms are possible in the Mid-Atlantic on Saturday as the system turns to the northeast. Some of these storms could create tornadoes, bringing dangerously damaging winds.
There is an enhanced threat (Level 3 of 5) of severe storms from Norfolk to Savannah through noon Saturday, and a slight risk (Level 2) extends into central Florida.
Periods of heavy rain, high winds and hail are possible and an isolated tornado could even appear, the NWS office in Charleston, South Carolina reported.
“A strong line of thunderstorms is forecast to move through the forecast area in the early morning hours. As the cold front approaches the region, frequent gusts in the 40 to 48 km/h range are expected. as dawn approaches,” added the Charleston office.
Bomb cyclone roars off the East Coast
And further north, the system is expected to strengthen into a bomb cyclone on Saturday and bring damaging winds and heavy snow, especially to parts of the inland Northeast, making travel difficult.
A bomb cyclone forms when a storm drops its pressure by 24 millibars (a measure of pressure) in less than 24 hours.
4 to 6 inches of snow is possible in the Tennessee and Ohio river valleys, with more than a foot possible in parts of upstate New York and northern New England. A blizzard warning is also in effect through mid-afternoon Saturday for portions of Northern Virginia through Blue Ridge.
“Snow rates of more than 25mm per hour combined with wind gusts…will severely reduce visibility and make driving conditions difficult or dangerous,” the Weather Prediction Center (WPC) said on Friday. “Heavy, wet snowflakes can cause scattered power outages,” the WPC added.
Metropolitan areas along the coast, including Washington, DC, Philadelphia, New York and Boston, are expected to collect mostly rain, although some snow could fall before Sunday.
More than 60 million people were under winter weather alerts from the NWS Friday night, from Texas to Maine.
New York State activated its Emergency Services Operations Center Friday night ahead of the impending storm.
“With up to a foot of snow forecast in some locations, this system is expected to create hazardous travel conditions for the next 36 hours, and New Yorkers should do everything possible to stay off the roads during this time,” he said. Emergency Services Commissioner Jackie Bray said in a news release Friday.
The midsection of the country will see temperatures -1 degrees below average from Texas to Minnesota and single-digit wind chills across the Great Lakes and the Northeast through the weekend.
Travel disruptions are expected for drivers and airline passengers. Nearly 400 flights have already been canceled for Saturday, including more than 100 JetBlue flights, according to tracking website FlightAware.
Trends Wide’s Jason Hanna, Aya Elamroussi and Derek Van Dam contributed to this report.