Day 2 of Baltimore, MD (KBWI)

Good radiational cooling led to a low of 23F last night. It has clouded up, but not as much as expected, with enough sun to mix out the very shallow but sharp inversion somewhat, leading to a high of 46F, higher than almost all models. The winds have been very weak too, with a maximum of 7-8 kt so far with a Chesapeake Bay breeze occurring now. The snow cover is pretty much gone now. After an initial cooldown with decent radiational cooling this evening with a bit of clearing and no wind, thickening low-level clouds will stop the cooldown after 06z or so tonight, leading to an early low. Tomorrow, a slow warmup will ensue, greatly mitigated by thick low cloud cover and some cold air damming east of the Appalachians. The high is expected to occur at the end (Thursday 06z) with weak warm advection and clouds continuing. Some models are suggesting that the southerly winds will get going at around the end, which would lead to a sharp warmup around then, but I would bet against that and lean cold given the tendency of shallow low-level cold air like this to persist longer than model guidance, especially when forcing to scour it out is weak like in this case (no strong low pressure system or strong low-level jet). The GFS does appear a bit too cold however. The cold, stable low-level air will also prevent the southwesterly winds aloft from mixing to the surface, and winds will be rather weak again. A few showers are likely in the afternoon or evening, though it is expected to be intermittent and not much, with most of the dynamic forcing staying to the north.

 

Source: PivotalWeather