Rain may fall but is unlikely to ruin your weekend

You may have heard forecasts for a wet and unsettled weekend.  That’s only partially true.  Extended windows of the upcoming weekend may well end up dry.

The best chance of rain over the next several days is Friday night, when a wave of low pressure rides up a front draped along the East Coast.  The rain may even be heavy at times, filling gauges with around 0.5-1″ of water, although there’s quite a spread in model output (some only show light amounts of rain). Some models focus much of the rain east of the Chesapeake Bay.

Forecast weather map at 8 a.m. Saturday morning shows low pressure to the northeast of Washington, with a front along the coast (NWS)

Forecast weather map at 8 a.m. Saturday morning shows low pressure to the east of Washington, with a front along the coast (NWS)

 

My hunch is that the bulk of the rain that falls over the next 5-days in the immediate D.C. area may concentrate in this Friday night wave.

NWS 5-day rainfall forecast (National Weather Service)

NWS 5-day rainfall forecast (National Weather Service)

By Saturday, model forecasts are converging on the idea that the front will push far enough east  that the balance of the day may turn out dry with just a slight (20-30 percent) chance of scattered showers.  Saturday outdoor plans may turn out OK.

The front may drift back inland towards the metro area on Sunday but – at least as of now – showers and storms that form along are more likely to be scattered rather than widespread. There’s no apparent well-defined upper level system to focus rain.  The best chance of rain Sunday would be in the late afternoon and evening hours but – at this point – doesn’t appear to exceed around 40 percent.

Admittedly, details on the timing and intensity of rain through this period is lower than normal.  Slight changes in the position of the front – which is a bit of a moving target –  could shift the region most likely to receive meaningful rain.  Right now, the Delmarva  peninsula and Md./De./Va. coastal areas seem most prone to extended periods of cloudy and rainy weather through the day Saturday, unfortunately for beach-goers.  But stay tuned for updates since forecast specifics could change.

Here in the metro area, we’re riding a statistically unlikely four-month streak in which essentially no rain has fallen on the weekend, including last weekend when it was forecast.  There’s some chance we could dodge the bullet again  - although given the pattern – I think we’ll be challenged to shut out the rain entirely.

Also on Capital Weather Gang

Mars 2020 rover will carry weather instruments to research future manned missions