Baltimore is in for a mix of weather patterns this week, starting with a cold front tonight, followed by a drier and less humid Monday. According to the National Weather Service Baltimore MD/Washington DC, the presence of a stalled front across PA into NJ this morning, bringing quick-moving showers to the Alleghenies, which will then move east—expect a very quick light shower or drizzle for most areas.
The weather service predicts one final hot and humid day with highs reaching the upper 80s to low 90s and heat indices in the low 100s east of the Blue Ridge before the cold front slides through, bringing some coverage of showers and maybe a few thunderstorms this afternoon, the most likely development of these along and north of the Potomac. While the Storm Prediction Center has maintained a Marginal Risk for severe storms, the overall threat for the area is conditional. There will be sufficient shear/instability for any storm that develops to become severe, potentially. The main threat from any severe storm will be damaging wind gusts, as the front is expected to progress quickly to the east. However, the backside will be slower to exit from the Central Appalachains to the central Shenandoah Valley, with ongoing showers in those areas tonight.
Monday welcomes a cold front crossing by sunrise, except along the Central Alleghenies, accompanied by lower humidity levels. However, scattered showers and thunderstorms could still occur along the I-64/I-81 corridor to the south and west. Come Tuesday, a reinforcing trough further cools things down, with high temperatures only reaching the low 80s and dew points dropping to the 50s and low 60s.
The long-term outlook through Saturday suggests mostly sunny skies and below-normal temperatures initially. Still, Baltimore will not remain cool for long—by the end of the week, high pressure moves offshore and southerly winds usher in the return of heat and humidity, with dewpoints reaching into the 70s and high temperatures potentially hitting the mid to upper 90s, and although shower and thunderstorm activity might remain limited on Thursday, a few storms are expected around on Friday as the upper-level ridge starts to weaken. By Saturday, a weak frontal boundary could provoke afternoon thunderstorms amidst the continued hot and humid conditions.
In aviation, VFR conditions are expected today, with lower coverage of afternoon showers and thunderstorms not warranting inclusion in terminal aerodrome forecasts at this time. However, a cold front tonight will ensure VFR conditions for the start of the week. For mariners, a briefing from the National Weather Service alludes to a "Small Craft Advisory from 3 AM to noon EDT Monday for ANZ532>534-537-540-541-543," due to northerly winds behind the front.
