"Copious" rain today; snow risk fades
Forecasters out at Sterling have had a devil of a time working this week's brewing storms. But they've settled on one thing: we're going to see lots of rain in the next 24 hours.
It's also becoming more likely that any changeover to snow we may see early Friday morning will be fleeting, and unlikely to have much impact in the Baltimore region. Temperatures just won't be cold enough here. Out west, say, from Frederick west, snow, sleet and freezing rain may become more of a headache. First the rain.
"It looks like it's going to rain quite a lot today," forecaster Andy Woodcock said in this morning's discussion from Sterling.
Gulf moisture is streaming north along the east side of a cold front. The national radar loop is pretty impressive. West of the front, the cold air is driving snow as far south as Galveston and Houston and parts of Louisiana. The heavy rain will be welcome in the South - places like northern Georgia, western S.C. and N.C. and eastern Tenn., where they've been suffering with extreme drought for several years.
The heaviest precipitation should arrive here between mid-afternoon and midnight tonight. The forecast calls for up to an inch today, 1 to 2 inches tonight and another quarter- to a half-inch tomorrow before it's all over. I would anticipate a slow evening rush hour today.
You can track rainfall at The Sun's weather station, at Calvert & Centre streets, here.
With all that rain coming, the NWS has issued flood watches through Friday morning for all of eastern Maryland, from Ocean City westward to Harford, Howard, Baltimore and Montgomery counties. Two to 4 inches are possible, and if it rains that hard, small streams are likely to overflow their banks onto low-lying roads.
Which triggers the usual reminders for the dim of mind: Do not try to drive through flood waters. Turn Around; Don't Drown. You just won't believe how little water it takes to float your car until you're sailing downstream with creek water streaming across your feet.
That said, if you see flooding and can shoot pictures safely, please do so and send them, along. I'd love to post some.
We can expect seasonable highs in the upper 40s today, dropping to 36 overnight. Forecasters are holding open the possibility that some of the overnight rain may mix with freezing rain or snow in the early morning hours, west of the urban centers.
But such wintry precip will be more of a headache from Frederick westward into the mountains. Winter weather advisories are up for those counties. Here's how they're calling it this morning:
"Essentially east of Rte 15 [running north and south through Frederick] will be all rain. Precipitation will experience changes west of there ...We'll have freezing rain in the western quarter of the area. In the pre-dawn hours, as colder air works into the column [of air], precipitation type will be snow west of I-81 and between 81 and 15 a mix of rain and snow. 'Wintry mix' is good wording for the zones along I-81 for the overnight hours."
"Any snowfall bands or areas that move across the mid-Atlantic are expected to be light, fairly short-lived and subject to rapid melting over the overnight rainfall activity and surface temperatures a few degrees above freezing."
The storm is forecast to spin up the coast quickly late on Friday, leaving us with mostly sunny skies through the weekend.