Quick morning update to show the HRRR (High Resolution Rapid Refresh) model for potential snowfall through this evening: Winter Storm Warnings were dropped with a Winter Weather Advisory posted mainly for Maryland and Loudoun county Virginia.
What went wrong with the forecast:
The trough axis shifted further north than what most of yesterday afternoon’s models had indicated, hence the dry slot will be punching further north into the immediate DC area.
Temperatures did not drop as much due to the lack of precipitation intensity overnight. All and all this will be a northern Maryland event with a general 3 to 5″. Some folks near the Pennsylvania border could pick up 6 to 7″.
I congratulate the European forecast model for being the closest in accuracy of keeping most of the accumulating snow (that is above 2″) north of the Potomac.
I am still watching the models for a potential snow storm around/after President’s Day.
DC Storms 
Some models are saying that there might be some so ow showers tonight is that true?
Terrible. I don’t consider a snow event a snow event unless it sticks to the roads. I didn’t feel comfortable with the forecast starting yesterday as I know these events can start as rain and never change to snow. We had a similar event last year where it was in ing 40s the day before and it started as rain but never materialized after that. Hope we still have some cold air for a presidents day coastal storm.
This was not at all a typical snow situation, no real coastal storm, no high banked up to the north. Plus the area of precip was so small, that flap of a bird’s wings could move it out of the area.. Not at all an easy situation.