Watching Independence Day Weather

Synopsis:

Surface low sitting to our southeast will provide continual onshore flow keeping much of New England under low clouds for the next few days. The next system moves into the Great Lakes region on Monday, remaining in place for the better part of next week keeping clouds and a threat for showers over the area.

Discussion:

Upper level low with cold pool of air aloft sitting over the region today has helped trigger clusters of strong to severe thunderstorms in southern New England. Weak winds aloft has resulted in much training of storms with flash flooding an issue. Cheshire County northward has escaped much of this activity, sitting directly under the upper low with showers and thunderstorms rotating around us. We even managed a few hours of sun late this afternoon. This is an important point simply because the same pattern featured today will be repeated a number of times over the next week.

Tomorrow, same upper low sitting over us with surface low pressure to our east. An easterly wind flow will keep clouds locked in over eastern New England. The atmosphere will likely be more stable than today given a greater expanse of easterlies. Western New England could see some periods of sun, similar to today. Given this, weak instability could trigger afternoon showers. Cloudiness will keep temperatures in the mid 70's.

Monday, more of the same. Upper low scoots east ahead of the next one dropping into the Great Lakes region. Continued onshore flow with next frontal boundary approaching from the west will provide a good focus for convergence and more clouds and showers. High temperatures will be held back in the low to mid 70's due to cloudiness.

Tuesday, residual low pressure moves further out to sea, and with winds now out of the southwest we could see some breaks of sun again and warmer temperatures. Frontal boundary rotating toward the region will trigger afternoon showers and thunderstorms.

Wednesday and Thursday, upper low still hanging tough over the Great Lakes region. Triple point low develops to our south, reestablishing easterly flow with clouds and showers. As the upper low sags southward, cold air advection aloft will prevent temperatures from reaching any higher than the low 70's.

By Friday the upper low will lift northward, and we will finally see a return to a more zonal flow aloft. We'll see residual clouds and showers as a weakness rotates around the upper low, but temperatures will be on the rebound and with partial clearing on Saturday, highs could reach into the upper 70's to 80. Timing of the next frontal system is uncertain. Looks like we could see our next round of showers and thunderstorms by Sunday afternoon.