... High pressure will remain in place across southern Canada through the end of the week, leading to continued onshore flow locally. This area of high pressure will start to break down and shift southward heading into this weekend as ridging builds to our west over the Ohio Valley.
NEAR TERM /THROUGH TONIGHT/...
1015 AM Update: Drizzle and light rain has continued to come down across a large portion of the area this morning as a result of an upper trough situated over the Northeast and Mid-Atlantic states early this week with onshore flow. Likely PoPs have been added across the NE portion of the area this morning to account for an uptick in overall precipitation trends and accumulations realized. We'll continue to see these conditions into the afternoon and evening hours with highs in the 50s to near 60 for most areas.
Previous Discussion Follows: A strong area of high pressure will remain in place today over southern Canada, while a weak area of low pressure resides off the Mid- Atlantic Coast. Northeasterly flow between these features will maintain a marine influenced airmass over the region, leading to cloudy skies, occasional drizzle/light rain showers, and well below normal temperatures. With thick cloud cover in place, temperatures will hold steady in the upper 50s and lower 60s. Similar conditions are expected overnight tonight, with temperatures dropping back into the 50s.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... A similar synoptic scale pattern will continue into Wednesday and Thursday, with high pressure holding strong over Quebec. This will maintain northeasterly flow over the region through Thursday night. The high may strengthen and build just far enough south on Wednesday to get some weak dry advection to work into the area. As a result, chances for drizzle are expected to come to an end, and there may even be a couple breaks in the cloud cover on Wednesday. Skies will stay cloudy the vast majority of the time though. High temperatures on Wednesday are expected to reach into the mid 60s for most.
High pressure will remain in place to our northeast on Thursday, but upper level troughing will begin to build a bit further east from the Great Lakes/Ohio Valley. This will lead to an increase in cloud cover once again, along with renewed chances for showers. Temperatures on Thursday are expected to top out in the mid-upper 60s.
LONG TERM /FRIDAY THROUGH MONDAY/... An upper level trough will cross the area early on Fri. With limited moisture and stable air mass under NE sfc flow, expect very light rainfall amounts. Surface to upper level ridging builds in Saturday night through early next week leading to a finally clearing and warming trend heading into next week.