12z HRRR is rolling in and it likes Fairfax County and then the Bay and Eastern Shore. Pretty much meh in all other areas. I'm tempted to say the fat lady is singing for places from Loudoun/Frederick, MD and west. Right now I'd probably draw a polygon for best chances running from Baltimore proper WSW back to Gaithersburg, SSW to Fairfax and then perhaps down to EZF and then including everything south and east of that line.