Residents in the Baltimore area can breathe a bit easier as the flood watch alert has ended but should brace themselves for an intense heatwave expected to start this Sunday. The original alert was in place until 10 AM today for certain areas in Northeast Maryland and near the Chesapeake Bay, but radar trends show the intensity of rainfall has been less than anticipated. A slow-moving boundary previously concerning forecasters has weakened and is pushing eastward, setting the stage for a surge in temperatures early next week, according to the National Weather Service Baltimore MD/Washington DC.
The NWS detailed that Sunday will mark the beginning of searing heat and humidity, with the mercury expected to clamber into the mid to upper 90s. There's a defending ridge of high pressure to blame, ushering in clear skies and high temps, along with “heat indices in the upper 90s to low 100s” during peak afternoon hours. While the risk of heat advisories is currently low, that could change as conditions evolve. "Cannot completely rule out heat advisories for some of our eastern areas but confidence is low at this time in this coming to fruition," the National Weather Service forecast discussion states.
Conditions through Monday night are expected to include increased turbulence, with a high likelihood of thunderstorms, particularly on Wednesday as a cold front approaches. As the new week begins, the high pressure will submit, allowing for rising dewpoints and ongoing chances for localized thunderstorms. The possibility for strong to severe storms exists and will be a point of monitoring by weather services and locals alike.
Come Tuesday, the area might see record-breaking temperatures with the mercury potentially hitting the 100-degree mark. The NWS is predicting heat index values of 100-110 which could lead to excessive heat warnings. By comparison, Wednesday's temperatures are forecasted to be slightly cooler, although the stagnant, humid air could make it feel just as oppressive. With the front on Thursday and Friday stalling to the southeast, thunderstorms remain in the cards, especially south of Washington, DC.
For those hitting the skies, the aviation forecast from the NWS suggests generally clear flying conditions with some potential disruptions due to the scattered showers and storms on the horizon. Marine concerns have ameliorated since the waters have remained below Small Craft Advisory criteria this morning, except in areas affected by the heavier showers. As the week progresses, the potential for Small Craft Advisory conditions grows, particularly from Tuesday into Wednesday.
Climate data from the NWS shows that some daily high-temperature records for the July 15-17 timeframe may be tied or broken next week. With Prediction aligning closely with past high-temperature records, residents are encouraged to plan accordingly for the sweltering conditions.
