You might call it a January thaw - if there were any snow and ice out there to melt away in this April-like weather.
Clear skies, bright sunshine and a steady flow of warm air from the southwest pushed yesterday's temperatures into the 70s in the Baltimore area. The high at BWI Marshall Airport was 70 degrees.
It reached 63 in Annapolis before a bay breeze kicked up in the afternoon and dragged readings back to 49. But cities in central Virginia basked in 70-degree weather and temperature records tumbled from Chicago to Atlantic City.
"It's a gift to have such a nice day in the early part of January to get us through the rest of the winter," said Lisa Allender, who was outdoors at the Old Courthouse in Towson, reading a newspaper on a lunch break from her county job. "It is truly a blessing to have the warm sun on my face."
A blessing, and a nice break from the four-day cold spell late last week that sent Friday morning lows to 15 degrees at BWI - and even lower in the suburbs.
But this won't last, the experts warned.
"It's a classic example of a pattern that yields extremes," said Fred Gadomski, a meteorologist with Penn State Weather Communications. And it could turn on us again, with wintry weather returning as early as next week.
"Some [computer] scenarios - and it's way too early to be specific - suggest that early next week, portions of the Mid-Atlantic states could be digging out from a snowstorm," he said.
Last week's cold and this week's warmth are the product of a big and very strong high-pressure system. As it slowly traversed the region, clockwise winds around the center first drew cold arctic air southward into the region late last week.
As it shoves off into the Atlantic this week, the return flow of southwesterly winds is pulling mild air up from the Gulf of Mexico. This "seesaw of warmth and chill ... may end up characterizing this month," Gadomski said.
That's because the northern jet stream is dipping southward across the Western states, bring them extreme rain and snow, then heading north again into eastern Canada. That allows southern warmth to flow into the Midwest and Northeast.
That could reverse as early as next week, with the jet stream sweeping northward across the West, and then south over us, making us colder while the West gets milder.
"If the computer models were the truth of the weather future, it would be snowing in Baltimore and Washington next Sunday night," Gadomski said. "But ... the computer models can do a lot of things five or eight days in [advance] that never come to pass."
As unseasonably mild as it was, yesterday's high of 70 degrees at BWI fell short of the record of 74 degrees, set 101 years ago, on Jan. 7, 1907.
But Baltimore's forecast high of 66 degrees today could threaten the record of 69 for the date if enough sunshine burns through the morning fog.
January temperatures in the 60s, and even the 70s, are surprisingly common in Baltimore.
BWI saw a high of 71 degrees on Jan. 6 last year, and four straight days in the 60s a week later. There were eight days in the 60s in January 2006; and five in 2005 (including one 70-degree day).
Tom Taylor, who coaches girls soccer at the Community College of Baltimore County's Catonsville campus, was on a bench at the courthouse in Towson yesterday, enjoying the sunshine and a magazine while waiting for two team members to arrive for an award ceremony.
"It would be a great day for soccer practice," he said. "This is beautiful. And it's supposed to be 67 tomorrow. I'll go home and put my shorts on and do something outside."
In Columbia, Harry Bartelt, visiting from Germany, took a walk around Lake Elkhorn, enjoying the sharp contrast from the bleak, cold days back home in Berlin, where darkness arrives by 4 p.m.
"I enjoy it," he said, "but there's an uncomfortable feeling about it. There's almost a feeling of guilt." He is supposed to head back to Germany next week, where he works as a translator. "But ... I may stay longer if the weather stays like this," he said.
"You can't beat 60 degrees-plus in January," said Mark Zegowitz, a Realtor who seized the opportunity for a walk around the lake with his wife, Jennifer, their baby daughter and their dog. "It's kind of weird seeing ice right there. The birds are standing on it, and then we're wearing short sleeves."
Tomorrow's high could reach 58 degrees, but an approaching cold front will gradually raise the rain chances for tonight and tomorrow. More rain is possible Thursday and over the weekend, but temperatures should remain too mild for wintry precipitation.
This winter, the airport has recorded just 4.8 inches of snow. A mild and dry-to-average winter is typical for La Nina winters like this one. Precipitation is about average this winter, but scarce rainfall since last April has left the airport about 7 inches short.
Hydrologists have warned of trouble ahead if there's too little rain this winter to recharge soils and groundwater before the growing season arrives.
The latest U.S. Drought Monitor map shows that "moderate drought" persists on both sides of the bay, south of the Bay Bridge. And "severe drought" remains entrenched in 20 percent of the state, including extreme southern Calvert and St. Mary's counties, and the four southernmost counties of the Eastern Shore.
Baltimore City's three reservoirs remained at 68 percent of capacity last week, having recovered a bit from a low of 64 percent in the middle of last month.
To conserve supplies for use next summer, the city drew water from the Susquehanna River from Dec. 18 to 28. But pumping could resume as soon as tomorrow, city officials said.
Sun reporters Ellie Baublitz and June Arney contributed to this article.