The prognosis for outdoor plans over the weekend is poor.
May, normally one of the area’s nicest months, has had an inauspicious start this year. Forecasts for sunshine and warm temperatures have been foiled the past three days by clouds. Highs have generally fallen short of forecasts by about 5 degrees. Now comes the deluge.
Rain will develop toward morning on Friday and continue intermittently well into Sunday. Heavy downpours and embedded thunder are possible late Friday afternoon into the overnight hours.
There’s even an outside chance that a few thunderstorms late Friday could be severe with damaging winds gusts, but the more intense storms will probably occur in southern and central Virginia.
Considering the likelihood of heavy rain Friday afternoon and night, some areas could see flooding — especially as the downpours on Wednesday night helped moisten the ground; some spots west of the Beltway received upward of 2 inches. Poor drainage areas and streams that are prone to flooding will be most at risk. The National Weather Service may issue flood watches.
The intensity of the rain should ease some on Saturday, but it will probably still fall moderately at times amid chilly temperatures — only in the 50s. Light to moderate rain may persist through Saturday night, though occasional lulls are possible.
It will most likely be raw and damp on Sunday with drizzle and light showers — less than ideal for Mother’s Day — but the bulk of the rain will have fallen.
When will we next see the sun? That may take until Monday afternoon.
The responsible storm system is the same one that spawned tornadoes in Texas and Oklahoma on Wednesday, along with flooding from eastern Oklahoma into the Ozarks. As it passes through our region, it will be cut off from the jet stream, which ordinarily helps such systems move along. Although May often brings long stretches of warm, sunny weather, these cutoff lows are particularly common this time of year.
The lack of steering currents through the weekend means the storm will move at a snail’s pace, with rainfall piling up.
Here’s how much rain is projected through Sunday from different models for the District:
- American (GFS): 1.1 inches
- High-resolution Canadian: 2 inches
- UKMet: 2.1 inches
- Canadian: 2.2 inches
- NAM: 2.2 inches
- European: 3.2 inches
If you’re eagerly awaiting sunshine and sustained warmth, the longer-range forecast is promising. Next week should offer a significant warming trend, with highs climbing through the 60s and 70s and reaching the 80s by late in the week.