2/20 AM All Zones: Cooler Weather to Start the Week, More Warmth Returns Mid-Late Week

High pressure building in from the north, will support mostly sunny skies for this President’s Day. The weather pleasant overall. But it will be much cooler than over the weekend. Temperatures will rise into the upper 40s to lower 50s for highs over much of the region this afternoon. These are temperatures are still several degrees above normal for this late in February.

Then high pressure over the region will support mostly clear skies and calmer winds tonight. These will lead to some ideal radiational cooling conditions. Low temperatures will range from the lower to middle 20s over many of the suburbs to upper 20s to lower 30s closer to the more urban areas. Some of the interior valleys and the Pine Barrens could drop into the mid-upper teens.

More upper-level ridging begins building for Tuesday, with warmer mid-level temperatures But a deeper subsidence inversion aloft will keep mixing heights lower and mid-high level clouds increasing ahead of an approaching weak warm front. These will likely combine to keep  surface and high temperatures from rising out of the middle to upper 40s on Tuesday afternoon.

Then the  warm front accompanied by weak upper-level disturbance could produce some scattered showers tomorrow night, as the move closer to the region. Temperatures might be cold enough for some pockets of light freezing rain over the far northern interior valleys. But any precipitation and hazards will be likely very minimal and limited from this system.

Then more unseasonable mild weather returns for the rest of the week, as upper-level ridging continues to build into Northeast and Mid-Atlantic regions. Temperatures will be above normal this week at least in the mid-upper 50s to lower 60s. Even warmer temperatures closer to 70 are possible, if skies remain more clear with sunshine, especially by Thursday.

Then larger storm system with frontal boundaries may impact the region with more significant rainfall by Friday night and Saturday. Temperatures will still likely remain very mild through this period, as this storm will be tracking over the Great Lakes/Ohio Valley. Some chiller weather may return by Sunday, but temperatures are still expected to near or above normal. For more discussion on late this week and the extended term, check for more updates on the main dashboard this morning.