Update at 2:30 p.m. — Arlington is now also under a Severe Thunderstorm Watch.
A severe thunderstorm watch has been issued for parts of CT, DE, DC, MD, MA, NJ, NY, PA, VA, WV until 9 PM EDT pic.twitter.com/5IkasOqzn9
— NWS DC/Baltimore (@NWS_BaltWash) August 18, 2017
Update at 12:40 p.m. — A Flash Flood Watch has just been issued.
Flash flood watch issued for entire area until 2AM Saturday. PM storms will have heavy rain w/winds and hail poss. pic.twitter.com/jo9VBiFsCR
— Amelia Draper (@amelia_draper) August 18, 2017
Earlier: Today (Friday) is expected to run the gamut of summer weather.
Forecasters say high humidity may push Heat Index values as far north at 105 degrees. After roasting this afternoon, strong to potentially severe thunderstorms are expected to cool things down a bit this evening.
The National Weather Service has issued a Heat Advisory from Arlington, D.C. and the surrounding area. More from NWS:
HEAT ADVISORY IN EFFECT FROM 11 AM THIS MORNING TO 8 PM EDT THIS EVENING… THE NATIONAL WEATHER SERVICE IN BALTIMORE MD/WASHINGTON HAS ISSUED A HEAT ADVISORY, WHICH IS IN EFFECT FROM 11 AM THIS MORNING TO 8 PM EDT THIS EVENING. * HEAT INDEX VALUES… AROUND 105 DEGREES DUE TO TEMPERATURES IN THE LOWER 90S AND DEWPOINTS IN THE MID TO UPPER 70S. * IMPACTS… THE HEAT AND HUMIDITY MAY CAUSE HEAT STRESS DURING OUTDOOR EXERTION OR EXTENDED EXPOSURE. PRECAUTIONARY/PREPAREDNESS ACTIONS… A HEAT ADVISORY MEANS THAT A PERIOD OF HIGH TEMPERATURES IS EXPECTED. THE COMBINATION OF HIGH TEMPERATURES AND HIGH HUMIDITY WILL CREATE A SITUATION IN WHICH HEAT ILLNESSES ARE POSSIBLE. TAKE EXTRA PRECAUTIONS IF YOU WORK OR SPEND TIME OUTSIDE. WHEN POSSIBLE, RESCHEDULE STRENUOUS ACTIVITIES TO EARLY MORNING OR EVENING. KNOW THE SIGNS AND SYMPTOMS OF HEAT EXHAUSTION AND HEAT STROKE. WEAR LIGHT WEIGHT AND LOOSE FITTING CLOTHING WHEN POSSIBLE AND DRINK PLENTY OF WATER. TO REDUCE RISK DURING OUTDOOR WORK, THE OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION RECOMMENDS SCHEDULING FREQUENT REST BREAKS IN SHADED OR AIR CONDITIONED ENVIRONMENTS. ANYONE OVERCOME BY HEAT SHOULD BE MOVED TO A COOL AND SHADED LOCATION. HEAT STROKE IS AN EMERGENCY – CALL 911.
Active weather expected today with heat and humidity followed by strong to locally severe thunderstorms. pic.twitter.com/z9W5V6PxSs
— NWS DC/Baltimore (@NWS_BaltWash) August 18, 2017