Set Up For Thunderstorms
The next 36 hours will be stormy across the Finger Lakes. A warm, moist air mass will interact with a number of subtle impulses in the atmosphere to trigger a number of rounds of thunderstorms.
Thunderstorms will be possible at almost any time between now and Saturday evening due to the unstable air mass and numerous micro-boundaries that are the result of previous storms and the region’s complex topography.
However, there are a couple of times in particular when thunderstorms appear to be the most likely as waves of atmospheric energy swing through the region. The ample amount of moisture in the atmosphere and moderate wind fields aloft will organize at least some of these storms into stronger clusters.
For Friday, thunderstorms will be most likely between Noon and 5 PM. Two seperate rounds of storms are possible during this time, especially over the eastern Finger Lakes.
On Saturday, multiple rounds of thunderstorms will again be possible. The window for severe weather is quite broad and could occur anywhere from as early as Noon to as late as 10 PM.
Friday’s Storm Details
An area of rain out ahead of a disturbance is present over western New York early this morning.
This area of rain should dissipate as it heads east, but may help trigger new development over the central and eastern Finger Lakes during the midday hours.A couple of clusters of stronger storms will be possible during this redevelopment phase during the early afternoon hours. The greatest threat will be from roughly Keuka Lake eastward.
A second complex of storms may develop further west as the disturbance moves into the area. This would most likely develop during the early afternoon hours and should track across the Finger Lakes before dinner time. This could result in parts of the eastern Finger Lakes being hit twice, increasing the flash flood potential over those areas slightly.
The primary concern today will be strong winds, though there is a minimal hail threat as well. Torrential downpours are likely, but storms should generally be progressive enough to limit the flood potential.
The storm coverage will be faily scattered due to the clustering of the storms and many areas will probably hear thunder, but not actually see much of a storm. Only localized severe weather is expected.
Saturday’s Storm Details
Severe thunderstorms will be more likely on Saturday due to better support aloft from the jet stream and upper atmosphere patterns. A strong cold front will also act as a stronger forcing mechanism, making thunderstorms quite likely across the Finger Lakes.
Again, multiple rounds of thunderstorms will be possible as a number of disturbances, fronts, and micro-boundaries all interact with the unstable air mass.Thunderstorms will be possible at any time Saturday, but the greatest severe threat will be during the afternoon and evening hours. More locations will likely see severe weather on Saturday than on Friday. At this time, it appears possible that a lull in the activity may occur during the late afternoon, but this remains quite uncertain.
Damaging winds will again be the primary threat, but there will be a more substantial hail threat as well. An isolated tornado cannot be ruled out, especially considering the complex nature of the interacting boundaries.
Flash flooding could be a concern as well. The atmosphere will remain primied for torrential downpours. With multiple rounds of storms possible following Friday’s rains, a few localized areas could see substantial amounts of rain during this period.
Thunderstorms will be more likely to organize into line segments that will span a wider area than Friday’s clusters of storms.
Outside of the Storms
During the periods where it is not storming, the Finger Lakes will have a mix of sun and clouds. Temperatures will be warm and humidity levels will be muggy.
High temperatures on Friday will mostly be in the upper 70s to near 80 degrees. Temperatures may get a couple degrees warmer on Saturday with mostly low 80s.
Temperatures will drop back into the 70s or even upper 60s as thunderstorms roll through, but should quickly rebound after the rain ends.
The overnight temperatures will remain mild tonight, with lows around 70 degrees for many areas.
The weather should improve on Sunday behind the cold front. A couple isolated pop-up showers or light storms may be possible during the afternoon, but many areas should stay mostly dry. Temperatures Sunday will be in the upper 70s, but the humidity levels will drop.