The current mild weather pattern will continue through Thursday, as temperatures will remain well above average for the third week of February.
The morning commute on Thursday could be slowed due to icy roads, as early morning rain will freeze on paved surfaces that will be below freezing.
Warmer air will surge northward during the day and temperatures will approach 50 degrees in the afternoon.
Roads will become wet by midday, as waves of rain will move through Chicagoland during the day. The rain could be accompanied by lightning and rumbles of thunder.
However, rain, snowmelt and frozen ground will combine to create an increased threat for flooding, especially in low lying and poor drainage areas.
By the end of the week, temperatures will dip back into the 30s and then plummet to below freezing by Sunday. The colder pattern is likely to persist through much of next week.
It will not feel like an early May week around Harrisburg this week with June-like warmth dominating.
Monday is shaping up to be Philadelphia's warmest day so far this year, kicking off a week that will be dominated by summer warmth.
Monday is shaping up to be New York City's warmest day so far this year, kicking off a week that will be dominated by summer warmth.
Early indications suggest that the first tropical system of 2015 could spin up off the southern Atlantic Coast of the United States this week.
After a cooler-than-normal summer 2014, the Northeast can anticipate more 90-degree days. Meanwhile, drought conditions will expand in the West.
Parts of this week will feel more like summer across the Midwest and Northeast with the warmest days of 2015 set to unfold.
Eastern U.S. (1812)
May snowstorm swept from Philadelphia northeastward to Maine. Snow covered ground in New York City; 12" accumulated near Keene, New Hampshire, 9" fell at Waltham, Mass., near Boston.
Severe snowstorm: 33.8" in Havre (24.8 inches of which fell in 24 hours).
New Orleans, LA (1978)
Persistent thunderstorms caused worst flooding in 30 years at New Orleans; lightning ignited an oil storage tank at Covent, LA.