Typical Mid-August Weather
The weather over the first part of the week will be very typical of mid-August in the Finger Lakes.
Our weather pattern early this week is most influenced by a dip in the jet stream over the Great Lakes. While no major weather systems are heading our way, a few weak disturbances will be caught in the atmospheric flow and will move into the region.
This will result in periods of clouds alternating with some sun throughout Monday and Tuesday. A stray shower or two will also be possible at most any time during the daylight hours and early evening.
The best chance for rain will be on Tuesday afternoon as a slightly more organized disturbance moves through, coinciding with the peak heating of the day.
Scattered showers and a couple of thunderstorms should develop despite an overall marginal environment. Some gusty winds may briefly accompany the thunderstorms, though severe weather is generally not expected.
I would expect roughly half of the region to see rain on Tuesday, while the other half remains mostly dry.
Temperatures will be right on the climatological averages, with highs both Monday and Tuesday around 80 degrees. Tuesday morning should start a bit warmer than Monday did, with lows mostly in the low 60s.
A bubble of high pressure will slide through on Wednesday, bringing sunny skies to the Finger Lakes. Temperatures may retreat a degree or two, with highs in the upper 70s.
Turning Wet Late Week
The weather will turn more active towards the end of the week. A stronger area of low pressure will move into the Great Lakes on Thursday, pushing a warm front through the Finger Lakes. This low will then pass by to the north on Friday before slowly departing for the weekend.
Copious amounts of atmospheric moisture will surge north ahead of this system with the warm front on Thursday. The amount of moisture in the atmosphere could rival some of the air masses we saw in late June and early July as far as its potential for torrential downpours.
The key to how Thursday’s weather evolves will be the position and progression of the warm front. If the front sets up north of the Finger Lakes, rain will still be possible, but the heaviest may stay north. If the front slows and sits over the Finger Lakes, some areas could see excessive rain.
The good news is that conditions have been relatively dry for a couple of weeks. This has improved the soil’s capacity to handle heavy rain. Still, the flooding potential will need to be watched.
Additional rain and thunderstorms will be likely on Friday and possibly lingering into the weekend as the low passes by.