What a weekend in Baltimore! If you watched the forecasts going into this weekend you saw the weather presenter (me included) forecast 60 for Saturday afternoon and middle 60's for Sunday afternoon. This would have placed Baltimore and MUCH of Maryland some 20 degrees above normal overall! Man that would have felt great! However, it never happened!
So what went wrong?
The idea on the table was a gigantic, albeit a short warm up, was expected for Saturday and Sunday. A warm front was anticipated to cross the state delivering limited sunshine and a southerly wind to allow for temperatures to spike into the low and middle 60s. All of our forecast models suggested temperatures would hit between 60-63 on Saturday and 65-70 on Sunday. Since our guidance was locked into this idea we went along with it. That being said it was wrong and we were duped by our own technology.
So why didn't we hit 60° +???
As the warm front mentioned above moved north it encountered a stronger area of high pressure (stronger then modeled) situated over Boston. This high pressure BLOCKED the warm air from moving north trapping it over Baltimore, DC, Fredrick, York, and Philadelphia. This situation is called COLD AIR DAMMING or the process in which you lock cold air into a region forcing the warm air to throw the breaks on.
As the warm air moved north the cool air remained on the ground creating fog for most of Saturday and especially Sunday. As fog formed, it kept the air over Baltimore stable and held the temperatures in the upper 40s to near 50 at MAX!
NOTE how the temperatures warm some 20 more degrees south in Charlottesville! This is where the warm front stalled out and never moved north!