FNUS71 KLWX 221353 FWSLWX Spot Forecast for Grand Prix...NPS National Weather Service Baltimore MD/Washington DC 953 AM EDT Sat Aug 22 2026 Forecast is based on forecast start time of 1000 EDT on August 22. If conditions become unrepresentative...contact the National Weather Service. Please contact our office if you have questions or concerns with this forecast. .DISCUSSION... Based on latest satellite and radar trends, it appears showers this morning will remain southeast of Washington DC over Charles County and southern Prince Georges County. However, there is still the possibility of a shower or thunderstorm this afternoon, mainly between 3 PM and 7 PM, and perhaps another round of showers or thunderstorms around midnight tonight. An area of low pressure along the Mid-Atlantic coast will ride along a stalled boundary and bring rain and some thunderstorms throughout the day today. Additionally, a cold front will push through later this evening into tonight, bringing another chance for showers and storms. High pressure tracks in from the Tennessee and Ohio Valleys early next week which leads to a cool down with less humidity. Dry conditions are expected Sunday and through the first half of next week. .REST OF TODAY... Sky/weather.........Cloudy (85-95 percent). Numerous showers late in the morning, then scattered showers and thunderstorms in the afternoon. Chance of pcpn......70 percent. Chance of thunder...29 percent. Max temperature.....Around 79. Min humidity........74 percent. Surface winds (mph).East winds 5 to 7 mph. TIME (EDT) 10 AM NOON 2 PM 4 PM Sky (%).........100 91 81 80 Weather cov.....NUMRUS SCTTRD SCTTRD SCTTRD Weather type....RNSHWR RNSHWR RNSHWR RNSHWR Tstm cov........ ISOLTD ISOLTD Chc of pcpn (%).70 50 40 40 Chc of thdr (%).10 20 20 20 Temp............73 74 77 78 RH..............90 87 79 79 Surface wind....E 5 E 6 E 7 E 7 Surface wnd gst.9 12 12 12 .TONIGHT... Sky/weather.........Mostly cloudy (75-85 percent). Showers likely and scattered thunderstorms in the evening, then chance of showers and slight chance of thunderstorms overnight. Chance of pcpn......60 percent. Chance of thunder...29 percent. Min temperature.....Around 68. Max humidity........100 percent. Surface winds (mph).East winds 5 to 6 mph early in the evening becoming light. TIME (EDT) 6 PM 8 PM 10 PM MIDNGT 2 AM 4 AM Sky (%).........80 83 86 87 84 74 Weather cov.....SCTTRD CHANCE LIKELY CHANCE CHANCE S CHC Weather type....RNSHWR RNSHWR RNSHWR RNSHWR RNSHWR RNSHWR Tstm cov........SCTTRD CHANCE CHANCE S CHC Chc of pcpn (%).40 40 60 40 30 20 Chc of thdr (%).30 30 30 20 10 10 Temp............77 75 72 71 70 69 RH..............82 84 93 97 100 100 Surface wind....E 6 E 3 NE 1 NW 1 N 0 SW 1 Surface wnd gst.10 7 5 3 2 3 .SUNDAY... Sky/weather.........Mostly sunny (35-45 percent). Chance of pcpn......10 percent. Chance of thunder...7 percent. Max temperature.....Around 85. Min humidity........50 percent. Surface winds (mph).Light winds becoming west 5 to 10 mph early in the morning. TIME (EDT) 6 AM 8 AM 10 AM NOON 2 PM 4 PM Sky (%).........60 43 30 22 19 28 Weather cov..... Weather type....NONE NONE NONE NONE NONE NONE Tstm cov........Chc of pcpn (%).10 0 0 0 0 0 Chc of thdr (%).10 0 0 0 0 0 Temp............68 70 76 81 83 85 RH..............100 97 76 60 55 50 Surface wind....SW 2 W 5 W 8 W 10 W 10 W 10 Surface wnd gst.6 8 15 17 17 17 $$ Forecaster...Rosa Requested by...Jared Sorensen Type of request...OTHER .TAG 2620234.0/LWX .DELDT 08/22/26 .FormatterVersion 2.0.0 .EMAIL jared_sorensen@nps.gov