UPDATE, 12:30 p.m.: The National Weather Service has extended the Flash Flood Watch until 6 a.m. Friday. "There is increasing concern that moderate to heavy rain will continue in the I-95 corridor until past midnight."
Portions of Maryland between the Blue Ridge and the Chesapeake Bay could see a whole lot more rain than we've clocked so far. Check out this from the National Weather Service's morning forecast discussion:
"WIDESPREAD HEAVY RAIN WILL CONTINUE ACROSS THE ENTIRE [FORECAST AREA].
MESOSCALE BANDS OF HEAVY RAIN WILL ENHANCE RAINFALL RATES TO
AROUND 3-4 INCHES PER HOUR ALONG AND EAST OF THE I-95 CORRIDOR.
"AN ADDITIONAL 2-3 INCHES OF RAIN CAN BE EXPECTED EAST OF THE BLUE
RIDGE WITH LOCALLY HIGHER AMOUNTS OF 6 INCHES ACROSS THE WESTERN SHORE
OF THE CHSPK BAY. WE COULD BE TALKING ABOUT STORM-TOTAL RAINFALL
AMOUNTS LOCALLY OVER A FOOT ALONG THE WESTERN SHORE."
Prof. Jeffrey Halverson, at UMBC, says he's worried we may see a second slug of heavy rain tonight as a second low, the actual remains of Tropical Storm Nicole, cruise past the region.
Eric the Red agrees:
"The second low, which is the actual remant circulation of Nicole, is expected to lift north toward the region tonight. Models differ on the speed... with the GFS [model] bringing heavy, heavy rain from this system into the region this eve, and has it ending by tomorrow morning.
"The NOGAPS has similar timing. The Canadian and UKMET are slower... and have the torrential downpours with this second part of the event occurring a bit later tonight into tomorrow. Since the second low - remnants of Nicole - are expected to pass just to our east, the tornado threat is not as great (thankfully). I think a compromise in timing makes sense... so an additional period of heavy rain tonight and ending in the morning.
"Total rainfall amounts under this new scenario double, if not more. 4-8" will be widespread, with the potential for higher amounts. If Nicole strays a bit to the east, then rainfall amounts will be less. I guess I've seen enough to buy into the double-whammy."
UPDATE, 12:20 p.m.: BWI-Marshall has recorded 3.46 inches of rain so far from this storm, bringing the month's total to more than 5.5 inches. Normal precipitation for BWI in September is 3.98 inches.
Meanwhile, there is still a Coastal Flood Warning up for the Western Shore. The high tide at Baltimore (chart) appears to be running about 2 feet above predictions.