First Wave of Rain
A pair of low pressure systems will impact the Finger Lakes this weekend with periods of rain, some heavy.
Thin clouds ahead of the first low are already in place to start Friday morning. These clouds will gradually thicken today, reducing the amount of sunshine filtering through. The afternoon should be dreary, but rain will likely hold off until the latter half.
The rain will slowly move from southwest to northeast, first entering the region around 2-3 PM and not making it to the northeastern reaches near Syracuse until around sunset.
It will rain steadily for several hours once it begins, followed by a slight lull overnight. Additional showers are then expected to develop and continue into Saturday morning. There may be enough showers for it to rain steadily for a couple more hours, especially early Saturday.
In all, by the time the rain tapers off around midday Saturday, around a half-inch of rain will have fallen.
Temperatures on Friday will be warmest in the north, where the rain will hold off longest. Low and mid 60s are possible along and north of I-90 with the Syracuse metro area likely seeing the highest temperatures. By contrast, the western Southern Tier, where the rain arrives first, will stick to the mid 50s for highs.
Nighttime temperatures will drop to the low 40s by Saturday morning. Even with showers tapering off and probably mostly ending for the afternoon hours, highs Saturday will only make it to the low 50s.
Southeast winds will blow steadily both Friday and Saturday. Wind speeds Friday will be around 10 mph, increasing to near 15 mph on Saturday. Friday’s gusts will be around 25 mph, but Saturday may occasionally gust over 30 mph, especially on hilltops.
It will remain mostly dry through Saturday afternoon, Saturday night, and into early Sunday morning. Temperatures Sunday morning will start off in the mid 40s.
Heavy Rain Sunday
The second low will track along the East Coast on Sunday, then north into eastern New York. This will place the Finger Lakes in a favored path for heavier rain, though there is still some uncertainty with the placement of the heaviest rain bands.
The rain should move in from south to north Sunday morning. The rain will likely become steady and moderate rather quickly but may be followed by a lull in the early to mid afternoon. Heavier rain is expected during the late afternoon and evening hours as the low moves into the area.
The heaviest rain is expected in a relatively narrow, south-to-north oriented band. This band will probably only be wide enough to impact one-third to one-half of the Finger Lakes region, with an even narrower core of the heaviest rain.
As such, rain totals Sunday will probably vary quite a bit, but localized amounts over two-inches will be possible. This could lead to some runoff and minor flooding issues. The rain should depart before the sun rises on Monday.
Southeast winds Sunday will turn to the southwest on Monday, increasing back to the 10-15 mph range. Temperatures will stick to the 50s both Sunday and Monday, with overnight lows between the two days in the low 40s.
Monday may not have widespread steady rain, but numerous showers should bubble up during the latter half of the morning and into the afternoon. Similar conditions are expected on Tuesday and Wednesday as well.
Temperatures will remain cool, with highs Tuesday likely failing to reach 50 degrees and only hovering around 50 on Wednesday. Monday night will see temperatures in the upper 30s. Tuesday night will reach the mid 30s. This is ten to fifteen degrees below average for the start of May.
Like this week, there is some hope for a dry day on Thursday before more showers move in for next weekend. A drying and warming trend is expected thereafter, though.
This graphic represents an average over the entire Finger Lakes region. Localized variations should be expected.