Like yesterday, today delivered delightful dry air even as temperatures soared to the upper 80s. A splendid evening closes out our duo of dynamic days before the weather takes a slow turn for the worse as the weekend wears on. On Saturday night and Sunday, soakings seem like a strong possibility.
Through Tonight: It’s an outstanding evening - whether you’re heading to the Redskins pre-season game or staying up until pre-dawn to catch a glimpse of the Perseid meteor shower and International Space Station flyby. Skies should remain mainly clear. Overnight temperatures gradually fall through the 70s , bottoming out in the upper 60s downtown to around 60 in the cooler suburbs. Winds are light.
Tomorrow (Saturday): A breeze from the south at around 10 mph transports tropical warmth and humidity, especially during the afternoon. That’s when the moisture streaming in builds up the cloud cover and scattered showers and thunderstorms are possible (30% chance). Afternoon highs are in the upper 80s to around 90.
Saturday night and Sunday: If you’re out on the town Saturday evening, showers and storms will probably be more miss than hit But as the night wears on, showers and thunderstorms should increase in coverage and intensity, especially in our western suburbs. Low temperatures are near 70.
On Sunday, showers and thunderstorms are likely, with the possibility of very heavy rain. It’s unlikely to rain continuously and deluges won’t occur everywhere. But several waves of rain are possible with totals around 0.25-0.5” at the low end and 1-2”+ on the high end. Clouds and rain hold afternoon highs to around 80.
Pollen update from Walter Reed: Today’s grass pollen levels were HIGH, weed pollen MODERATE and tree pollen LOW. Mold spores counts were unavailable.
Air quality update related to Dismal Swamp smoke: Earlier today, I wrote the air quality forecast for Saturday was code orange - unhealthy for sensitive groups - due to smoke particle pollution arising from a wildfire in southeast Virginia. That forecast has been improved to code yellow - moderate - as smoke concentrations are fortunately not expected to be as high. For those of you sensitive to particle pollution, the National Weather Service forecasts the highest smoke concentrations to occur around 3 p.m. Saturday.