After a spring-like weekend, Gobblers Notch’s most famous rodent may seem like a meteorological Nostradamus, but the humans who do it for a living insist it’s about to take a fall by a few degrees.
After highs in the mid-50s in Philadelphia on Friday and Saturday, a “major pattern change” is about to unfold that will bring winter back, or to a reasonable extent, forecasters at the government’s Climate Prediction Center say.
The area could see some snow on Tuesday, as the coastal storm pulls in cold air as it moves away and generates cold winds from the north.
»Read more: Yes, the groundhog did not see his shadow
Philly’s chances of a major blizzard looking like they were in the league with a half-court shot at the buzzer in a basketball game. The National Weather Service in Mount Holly forecast 0.3 inches in the city Tuesday morning.
“If anything, it’s probably going to underperform,” Alex Starman, a meteorologist with the Weather Service, said late Saturday afternoon.
But as the storm intensified over the ocean on Tuesday, “you have to watch the back end of it” (the storm, not the groundhog), said Tom Kenes, a senior meteorologist at AccuWeather Inc.
After the storm leaves, the company’s long-range forecaster, Paul Pastelok, sees a devastating cold snap from Punxsutawney Phil lasting four to six weeks, perhaps with a few breaks here and there. You may remember that an elephant saw his shadow and promised an early spring.
How cold will it get?
The consensus among meteorologists in government and the private sector is that what the Northeast is about to experience will be more akin to the common cold, rather than uncommon. Temperatures may be a little below Philly’s normal highs in the low 40s. Normal highs rise to the mid 40s by the end of the month when the sun feels new strength by the day.
In terms of wattage, according to NASA, the sun over Philadelphia on Sunday is similar to what it will be at the end of October.
Normal nighttime temperatures in Philadelphia don’t rise above freezing until March 10, so storms may have a modest supply of cold air to work with in order to produce snow. “It doesn’t have to be very cold,” Keynes said. In fact, some of Philadelphia’s coldest winters have been snow-deprived, which is likely due to cold high pressure dampening storms.
“There’s still hope,” said Patrick O’Hara, a meteorologist at the National Weather Service office in Mount Holly.
And for those who don’t associate “hope” with shovels and rock salt and don’t mind if this weekend’s weather continues indefinitely, it’s at least likely that the recent drought of snow will continue for some time.
What happened to winter?
Philadelphia is on track for one of the 10 warmest winters on record, and winter has recently begun to ease in much of North America.
In Winnipeg, where normal highs for this time of year are in the teens, rain actually fell on Wednesday, when the temperature rose to 37 degrees. the The average daily temperature that day was about 30 degrees above normal, according to Environment Canada.
»Read more: Winter in Philadelphia can be full of surprises
The planet is warming, but in this case El Niño was clearly a factor. Keynes said that higher than normal temperatures in vast areas of the tropical Pacific Ocean had the effect of flooding a large part of the continent with warm air coming from the Pacific Ocean.
While the southern track was active, the storms traveling along it did not move toward the coast, ignoring the mid-Atlantic and Northeast.
El Niño appears to be fading, but sea surface temperatures remain about 3 degrees Fahrenheit above normal, and its effects are likely to last for several weeks.
Upper air patterns over the Arctic now favor cold air filtering into the United States, but the vanishing snow cover over the northern Plains and warmth across much of Canada are at odds with the bitter cold seeping east, Keynes said.
The source area for the hail is likely to be in the Philadelphia area north of Quebec.
The storm is scheduled to cross the mid-Atlantic region on Monday, then intensify over the Atlantic Ocean. Northerly winds west of the center of the storm are expected to pull cooler air that could trigger a change from rain to snow Tuesday morning southward up the I-95 corridor.
»Read more: El Niño lives up to its reputation for consistency as it continues to impact weather in the United States
The weather service says a few inches are likely to accumulate north and west of the city.
Computer models see more threats later in the month, but isn’t that always the case?
“There will be chances of snow along the I-95 corridor from Washington to Boston,” Kines said.