ITHACA, N.Y. — Time to buy new garden gloves and grilling supplies. If you’ve been putting off mowing the lawn or you’re itching to get some plants into the ground, this week will provide you ample opportunity. High pressure will be over much of the Great Lakes region in the coming week, bringing seasonably mild temperatures and dry, stable air to Ithaca and Tompkins County.

Your Weekly Weather

A shortwave (pulse of instability) is moving east-southeastward across Upstate New York as it heads from the Great Lakes towards the Atlantic Ocean, sliding between two highs to its north and southeast. A band of light to moderate rain is currently working westward through the Finger Lakes, and will likely be passing into Ithaca by the time this writeup is posted. Temperatures to the east remain comfortably in the upper 60s to mid 70s with filtered sun, while to the west, temperatures have fallen with the incoming clouds and moisture, in the mid 50s to low 60s. Rainfall totals have been modest, generally less than 0.10″ with a few pockets in the 0.10-0.25″ range.

With some scattered showers behind the band as well, expect an initial steady half-hour or so of rain to give way to on-and-off showers during the overnight hours, gradually winding down towards morning. In total from this shortwave, expect 0.10-0.25″ of rain in most areas, and generally on the lower end of that interval. Today’s highs in the 70s will fall back quickly with the rain, with lows tonight in the upper 40s.

Behind that system, the high pressure to the northwest builds in to provide for a pleasant Monday. Clouds will decrease during the morning hours, with skies turning from mostly cloudy to mostly sunny by late in the day. Afternoon highs will top out in the high 60s in Ithaca, and mid 60s on the hilltops, with a light north wind. Monday night will be partly cloudy and cool, as calm air allows for more efficient radiational cooling. Lows in the lower 40s.

That high shifts south Tuesday, which will help squeeze a second shortwave out between it and the one to our southeast – think of it as like two hands squeezing a tube of toothpaste. Right now, Tompkins County looks to be on the edge of the low as it crosses Pennsylvania heading eastbound. at this point expect mostly cloudy but dry conditions in Ithaca itself, but if you’re heading west or south of Tompkins County Tuesday morning into afternoon, you might see some rain. It’ll be a little cooler as we’re in the cool sector of the shortwave, and highs will be in the mid 60s. Tuesday night will see skies clear out with lows in the upper 30s, and some patchy frost will be possible in the usual cool spots.

Behind that shortwave, the high sinks further south Wednesday, into the Midwest. This will serve two functions – blocking weak storm systems from getting to us, and stabilizing the local atmosphere for an extended period, while a more southerly core will channel steadily warmer air into Tompkins County. Skies will be sunny Wednesday with highs a little warmer, near 70. Wednesday night will see a few fair-weather clouds with lows in the lower 40s.

The center of the high moves southeast towards the Mid-Atlantic Thursday. With warmer air wrapped into its flow, expect a few fair weather cumulus with highs in the mid 70s. Thursday night will see partly cloudy skies with lows around 50.

A low passes to the north Friday, around the high. The only local effect will be some additional clouds, though still looking partly to mostly sunny. Highs will be in the upper 70s. Friday night will be partly cloudy with lows in the low 50s.

The weekend is looking fairly pleasant at this time. Saturday will be dry with partly cloudy skies and highs in the mid to upper 70s. Saturday night will be partly cloudy with lows in the low 50s. A Canadian low pressure storm system does appear likely to swing through late Sunday, but it will be later in the day. Expect increasing clouds, showers late, and highs in the lower 70s.

Graphics courtesy of the NOAA Climate Prediction Center.

Extended Outlook

Heading into the second half of May, the large-scale synoptic weather pattern is trending towards a ridge over the Mountain West, and a downstream trough over the Mississippi and Ohio River Valley. This setup will channel Pacific moisture into the Desert Southwest, as well as Guld Moisture into the Texas coast and Deep South. More continental air to the north will result in drier than normal conditions over much of the northern third of the continental U.S. – and with that heat in the Northwest, it’s not a great situation for those Canadian wildfires, which may impact our air quality if the smoke is lofted this way. Locally, with a downstream ridge over the Atlantic Coast, temperatures will be normal for mid-May, with drier than normal conditions.

Brian Crandall

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