After reviewing the afternoon and evening models, the general forecast ideas expressed below generally hold but we have a few fresh thoughts and developments to share:
Enough of the models show the potential for a heavy overnight burst of snow (Thursday night into Friday morning) that we’re increasing our projected totals from 1 to 3 to 2 to 4 inches.
The onset time for the snow Thursday has shifted slightly later with snow probably moving in between 11 p.m. and a little after midnight.
The likely window for heavy snow along with very difficult travel and low visibility is between about 1 a.m. and 3 a.m. Friday.
The snow should end by around 4 a.m. in the immediate area and 5 a.m. in our eastern suburbs.
Here is what the latest models are projecting for the District:
American (GFS): 5.5 to 6 inches
High-resolution NAM: 4 inches
HRRR: 3-4 inches
European: 2.5 inches
Canadian: 2.5 inches
NAM: 2-2.5 inches
High-resolution Canadian: 2-2.5 inches
Anticipating Thursday night’s snowfall, the National Weather Service has issued a winter weather advisory for the entire region. The advisory takes effect at 9 p.m. Thursday and continues until 5 a.m. Friday.
The Weather Service is calling for two to four inches of snow with isolated totals up to five inches. (As noted below, Capital Weather Gang is forecasting a hair less, one to three inches generally — but agree that locally higher amounts are possible.)
“Plan on slippery road conditions,” the Weather Service writes. “The hazardous conditions could impact the Friday morning commute. The heaviest snow is expected between 10 p.m. and 2 a.m. when snowfall rates of 1 inch per hour are possible.”