Residents in Baltimore and the surrounding areas should expect a break in the heat and humidity today, as lower rain chances and reduced moisture levels accompany strong Canadian high pressure moving in from the north, as reported by the National Weather Service Baltimore MD/Washington DC. The cold front we've been tracking is moving southward this morning, bringing a scattered shower to northern Virginia and the Shenandoah Valley. At the same time, the rest of us might only catch a glimpse of some sprinkles the front will have pushed south of I-66 by the time the sun rises. Still, it'll dawdle a bit crossing the central Appalachians, potentially sparking up a few late-morning or mid-afternoon thunderstorms in that region.
After a period marked by typically muggy mid-Atlantic summers, tonight might just bring some relief with what the National Weather Service is calling the first cool summer night in a stretch, dropping into the cozy 60s and even hitting upper 50s in higher elevations but not without pushing through a secondary front this evening that may sweep up any straggling showers in central Virginia. It's not just the overnight temperatures that'll have us reaching for an extra blanket; daytime highs are hovering in the low to mid-80s—a welcome reprieve from the recent swelter.
Looking ahead to midweek, the forecast holds fast with dry and seasonal weather, courtesy of that persistent Canadian high pressure that's settling in to keep things steady, with an easterly wind shift expected on Tuesday turning southeast on Wednesday as the high meanders offshore and though mid-level ridging begins to build Wednesday, any notable temperature upticks are forecast to hold off until the tail end of the week.
Conditions are primed to shift, though, as we edge closer to the weekend, an upper-level ridge is stuck overhead. A surface high-pressure system that's setting sail offshore will mark the return of the quintessential summer sizzle, complete with climbing dewpoints and a toastier feel to the air. Yet, the thunderstorm threat remains low for much of the forecast area, given the stubborn presence of high pressure; however, it will be much hotter, with highs reaching the mid-90s, and dewpoints well into the humid 70s. Friday has the makings of a real scorcher. We could be eyeing heat advisories, according to the National Weather Service.
In terms of aviation and marine impacts, VFR conditions are expected to prevail for pilots through midweek under the influence of high pressure. In contrast, mariners can anticipate Small Craft Advisory conditions this morning ahead of that incoming, say-goodbye-to-humidity-for-now cold front. Still, waters are predicted to simmer down by this afternoon and remain fairly placid for the first half of the week.
Coastal concerns seem minimal at the outset of the week, with water levels on the decline thanks to northerly winds in the wake of the front. Still, by midweek, the National Weather Service anticipates a rise in water levels as southeast winds intensify, potentially nudging Annapolis and other sensitive areas into minor flood stage territory.
