ITHACA, N.Y. — It’s a relatively quiet period of weather lined up for Ithaca and Tompkins County this week. Some clouds and showers will move through today and tomorrow as a weak low and its cold front moves across the area, then merging into a developing storm system to the southeast. Once that system lifts off to the northeast, though, high pressure will take the reins for the remainder of the week.

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Skies are mostly cloudy this afternoon as a weak low with associated cold frontal boundary pushes into Western New York. A developing low pressure storm system over the Mid-Atlantic is supplying additional moisture and cloud cover, though the bulk of the rain remains to the south.

As the atmosphere becomes moister, some scattered showers are likely later today and into the early overnight hours. These will be on-and-off with light to moderate amounts, generally less than 0.1″ of rain with a few 0.1-0.25″ areas. Skies will generally be cloudy, though clearer skies will temporarily build in primarily northwest of Ithaca. Highs this Sunday will be around 70. Sunday night will see drier conditions and mostly cloudy skies with lows around 50. Some morning fog may prove to be a hassle during your morning commute, particularly those of you who live in valley areas.

As the coastal system strengthens and oceanic moisture wraps around its circulation, that and an extended channel of instability from Sunday’s weaker, merging low will bring another round of light to moderate rain showers during Monday afternoon and evening. Skies will be partly cloudy with a light northwest winds and highs around 70. Monday night will see mostly cloudy skies and showers taper off towards midnight as the coastal low moves off to the northeast. Lows will be in the lower 50s.

High pressure moves in later Tuesday, though a few showers may persist northeast of Ithaca where overwrapping flow around the counterclockwise-circulating low keeps some remnant moisture and instability in the vicinity. Generally though, skies will be mostly sunny with highs in the upper 60s. Northwest flow and drier, mostly clear skies will make for a rather crisp Tuesday night, with starlit skies and lows in the mid 40s. Fall is a-comin’.

Wednesday sees high pressure overhead, with stable and pleasant conditions. It will be sunny with highs in the low 70s. Wednesday night will be cool and quiet, with mostly clear skies and lows in the mid 40s.

High pressure remains overhead Thursday. A slight shift eastward may advect modestly warmer air into the region, with mostly sunny skies and highs in the mid 70s. Thursday night will be partly cloudy with lows in the upper 40s.

High pressure shifts a little further to the east Friday. Skies will be mostly sunny with highs in the mid to upper 70s. Friday night will be partly cloudy with lows in the low 50s.

Looking into next weekend, it’s looking dry and on the mild side for the first day of astronomical autumn, with mostly sunny skies Saturday and highs in the mid 70s, and a dry Saturday night with lows in the lower 50s. It does seem like a low pressure system to the south may usher in some showers for Sunday, with highs in the low to mid 70s.

Graphics courtesy of the NOAA Climate Prediction Center.

Extended Outlook

Looking into the end of September, the large-scale weather pattern calls for an upstream jet stream trough over the Western United States, with a pronounced ridge of warmer-than-normal air over the Central and Eastern United States. This kind of pattern would likely channel moisture from the Gulf of Mexico and Atlantic northward, with somewhat above normal precipitation (and that still being rain this time of the year) expected across much of the country. On the tropical side of weather, Tropical Storm Nigel is likely to strengthen but remain out at sea, and another Cape Verde system may develop in the tropical Atlantic this week (to be named Ophelia if it does), but it’s too early to make any claims as to where that storm would end up going.

Brian Crandall reports on housing and development for the Ithaca Voice. He can be reached at bcrandall@ithacavoice.org.