ITHACA, N.Y. — According to statistics from the Northeast Regional Climate Center, for many parts of the Northeast, the first half of October has been the warmest on record. Although things have cooled down for the moment following yesterday’s cold front, another warm-up is likely mid-week before more seasonable (read: still a little warmer than normal) conditions return next weekend.

Your Weekly Weather

It’s a showery and cool Sunday across upstate New York following the passage of a strong cold front across the region Saturday. The sub-freezing air relatively close to the surface means a relatively steep environmental lapse rate (the rate at which temperature changes with height in the atmosphere), and since air is more buoyant when the ground and surface air are moist as they are now, this is all conducive for the development of showers and even a few thunderstorms across the area. Further instability comes courtesy of northwesterly winds picking up surface heat emission from the relatively warm waters of Lake Ontario.

The rest of Sunday will continue to be cool and unsettled, with mostly cloudy skies and highs in the mid 50s, perhaps upper 50s if the clouds can break up a little further. Scattered rain showers will continue into the evening, though any new rainfall amounts should be less than one-tenth of an inch. These unsettled, cloudy and showery conditions will continue overnight as the storm system stalls near the Gulf of St. Lawrence and northwest winds stirred by its counterclockwise circulation continue to advect cold air into the region. However, the moist surface and substantial cloud cover will limit the cooling from daytime highs, with overnight lows only falling back to the mid 40s. New rainfall amounts will be between one-tenth and one-quarter of an inch.

With that deep low in place over Canada, stalled but slowly weakening, expect another cool and rainy day Monday, with the cloud cover and cold air aloft preventing much daytime warming. Occasional light rain in the morning will taper off as the day progresses. Highs will be in the lower 50s with overcast skies early, opening up for a few breaks of sun by late in the afternoon. High pressure begins to build in from the Southern Appalachians Monday night, and the clockwise flow of that high will draw in milder air and limit cooling even as skies clear during the overnight hours, with lows in the mid 40s.

As that high stays in place to the south-southwest Tuesday, it’ll advect more mild air into its overall circulation and towards the Southern Tier. Not only does this stablizie the atmosphere, we’ll see a substantial jump in temperature. Highs Tuesday will be in the upper 60s with mostly sunny skies. Tuesday night will be dry with a few passing clouds and lows in the low 50s.

Wednesday will be a little warmer as the high reorients slightly and provides a more southerly component to the flow into Ithaca and Tompkins County. There will be a few more clouds, but overall quite pleasant, with those partly cloudy skies and highs right around 70°F. Wednesday night will see a fair amount of cooling with mostly clear skies, drying ground and dry air overhead, so lows will drop into the upper 40s before daybreak Thursday.

Another storm system will approach from the west Thursday, and the models show this system lagging a bit as it moves east-northeast. At least one model (the GFS) shows the core of the low reforming to the west while passing over Ontario. Ahead of the system, partly cloudy skies Thursday morning will give way to mostly cloudy skies and scattered rain showers during the afternoon. Southerly winds ahead of the system, amplified by the low’s counterclockwise circulation, will bring temperatures into the upper 60s for high even as cloud cover increases. Thursday night will see cloudy skies and periods of light to moderate rain as the associated cold front passes during the early morning hours Friday, with lows in the upper 40s.

Friday will once again see northwesterly winds and colder air aloft behind the low that will allow for persistent clouds and showers, so expect an unsettled day with occasional light rain, generally grey skies, and highs in the upper 50s. The rain will peter out Friday evening, with mostly cloudy skies overnight, lighter northwest winds, and lows in the mid 40s.

Next weekend is looking seasonably cooler if dry. Temperatures will be in the mid 50s for highs and around 40°F for lows, with partly cloudy skies both Saturday and Sunday.

Graphics courtesy of the NOAA Climate Prediction Center.

Extended Outlook

Looking ahead towards the end of the month and Halloween, some modest warming is in the cards as the ridge rebuilds to the west, with a reduced flow of warmer southerly air making its way into Ithaca and Tompkins County. Highs in the upper 50s to around 60°F are plausible for the period, a few degrees above normal but nothing extraordinary. Precipitation is expected to be near-normal for the period. Longer-range models do indicate warmer-than-normal conditions are likely to persist into November, so the first frozen precipitation event seems unlikely to be within the next few weeks.

Brian Crandall

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