High Pressure Loses Its Grip
The high pressure system that has brought us days of sunshine and warming temperatures will start to loosen its grip on our region as it departs via the New England coast.
However, with the high still nearby and to our east, we can expect one more sunny day with temperatures are their warmest point during this recent stretch of weather.
Skies are clear across the Finger Lakes to start the day, outside of some river valley fog in the usual locations across the Southern Tier. Most areas are starting well into the 50s, but scattered temperatures in the 60s are also being reported.
Temperatures will quickly rise this morning with full sunshine and a light south wind. By this afternoon, all areas will be at least around 80 degrees, while areas around and north of I-90 will be into the mid 80s. Mid 80s are also expected in the Genesee Valley and some localized pockets of the Southern Tier.
Mostly sunny skies are expected through the afternoon, with clear skies continuing into the evening. However, by midnight, thin clouds will start to work in from the west. These will increase overnight and should blanket much of the region by sunrise.
South winds will also increase overnight, reaching speeds of 5-10 mph. Combined with the increase in clouds, these winds will ensure a very warm night. Lows across the northern half of the region will be in the low and mid 60s. To the south, upper 50s are more likely.
Some sun may filter through the thin clouds early Thursday, but the cloud cover will continue to increase and thicken as the day goes on. South winds will continue to blow at speeds up to or around 10 mph.
Thursday will still be plenty warm, just not quite as hot as today. A few mid 80s may still be possible in the northwestern Finger Lakes, with low 80s stretching eastward across the I-90 corridor. South of I-90, upper 70s are more likely with mid 70s in some of the higher terrain.
Thursday Night will remain cloudy and warm with winds increasing slightly, still from the south. Overnight lows will be between 60-65 degrees.
Major Pattern Change
A slow-moving cold front will approach from the west on Friday, but will not make it fully into the area. Still, scattered showers out ahead of the front will start to move into the region.
This rain will be light and sporadic but could start to show up as early as the morning hours.
Winds will remain from the south on Friday, but wind speeds will decrease throughout the day. High temperatures will mostly be between 70-75 degrees.
Rain will increase Friday evening into a slow-moving band. This seems most likely over the western portions of the region, though the exact placement is still uncertain.
Overnight and into Saturday, this band will slowly press eastward. It should also expand, leading to widespread rain throughout the Finger Lakes on Saturday.
Some of this rain may be heavy and long-lasting, resulting in widespread rain amounts of 1-2 inches, but with locally higher amounts. For the most part, Saturday looks like a washout.
Temperatures will start Saturday in the low and mid 50s and will have a hard time rising more than a handful of degrees. High temperatures should occur sometime in the latter parts of the morning or perhaps the early afternoon, only topping out in the upper 50s.
The rain will pull out to the east during the late afternoon and evening hours with fairly quiet weather Saturday night. Temperatures should drop to the low and mid 40s by Sunday morning, which is actually about what is average for this time of the year.
Showers will increase again on Sunday, as will southwest winds. Wind gusts over 30 mph are likely. Afternoon highs will be around 50 degrees, with numerous hilly areas sticking to the upper 40s.
Temperatures will be similar on Monday with more scattered showers. Rain showers will be possible Tuesday but should gradually wind down. Temperatures may be a couple of degrees warmer than Monday.
A generally cool, unsettled pattern will persist through next week and beyond. It will not necessarily rain every day, but sunny, warm days, even remotely comparable to today, will be a thing of the past.
This graphic represents an average over the entire Finger Lakes region. Localized variations should be expected.