ITHACA, N.Y. — For those who think summer-like conditions came on a little too strong, a little too soon, this week will offer some relief. More seasonable warm temperatures will be present in Ithaca and Tompkins County through the week. However, some unsettled, showery conditions are likely as we head into next weekend.

Your Weekly Weather

It’s a warm and rather humid afternoon in Tompkins County, with southwesterly flow ahead of a cold front working its way across Upstate today – it’s near 90 in Albany, but in the 50s in Niagara Falls. This is the same front that triggered a derecho squall line across Ontario and Quebec yesterday that resulted in widespread damage and multiple fatalities.

While we won’t see anything that severe, there is enough instability in the atmosphere to encourage the development of strong thunderstorms, and the dynamics (change of winds in height/wind shear, warm humid surface air in the upper 70s) are suggesting a squall line of strong storms could develop in the late afternoon and early evening, 2-4 PM for the Finger Lakes and Central New York, later as one goes east. A Severe Thunderstorm Watch has been issued. Some potentially damaging winds and hail will be possible with the stronger storms embedded in the line, so pay attention if any severe thunderstorm warning pop up on your radio or cell phone, and get indoors if a storm is coming your way.

Once that frontal boundary presses through, temperatures will drop off pretty quickly this evening. A few less severe showers and thunderstorms are possible behind the squall line, which should taper off by sunset, when Ithaca will be in the low 60s with a gentle northwest breeze. Skies will be mostly cloudy tonight as cooler, drier, more stable air flows into the region, with lows overnight in the upper 40s.

Monday will be a touch on the cool side for late May, but fairly pleasant as high pressure builds in from the Midwest. It will be partly cloudy with a light northwest winds and highs in the mid 60s. Monday night will see calm air as the high shifts east, partly cloudy skies, and lows in the mid 40s.

Tuesday places Tompkins County on the backside of that high’s clockwise circulation, which will allow a light southerly wind to develop and bring milder air into the area. It will be partly cloudy with increasing clouds during the afternoon and highs in the mid 70s. Tuesday night will be mild and mostly cloudy, with lows in the mid 50s.

Wednesday sees a storm system move up from the Southern Great Plains into the Western Great Lakes. This will amplify the southerly flow, but the moist air and enhanced instability will create near-overcast conditions that will keep the temperatures in the mid 70s for highs, even with the southerly breeze. A few showers may pop up as well, though these will not be frequent. The low continues to move north, even retrograding to the northwest a little Wednesday night, which will keep the clouds in place, with near-overcast skies, some scattered showers, and lows in the upper 50s.

Thursday will see the core of the low begin to move eastward across the Canadian side of the Great Lakes. The low pressure storm system will intensify somewhat, which will strengthen southerly flow, and the approach of its cold frontal boundary will trigger more rain ahead of the system, though this looks to be more frequent light to moderate showers rather than thunderstorms. With a strong southerly breeze, mostly cloudy skies and frequent showers, it will be in the upper 70s for highs. Thursday night will be mostly cloudy with showers with highs in the low 60s.

The slow frontal passage will pretty much take all day Friday to shift winds from the south to the northwest. With the primarily westerly breeze as the winds turns, it will be partly cloudy but showery day with highs in the low 70s. Any remaining showers will taper off shortly after sunset Friday, with partly cloudy skies Friday night and lows in the mid 50s.

For the start of Memorial Day weekend, it looks pretty good for your outdoor activities as high pressure remains in control for Saturday and Sunday, with a building ridge of warm air Sunday and Monday. Highs will be in the mid 70s Saturday with partly cloudy skies with mid 50s for lows Saturday night, and low 80s for Sunday with low to mid 60s for lows. Temperatures could get close to 90 on Monday, for those of you who have a three-day weekend.

Graphics courtesy of the NOAA Climate Prediction Center.

Extended Outlook

Looking ahead into the start of June, the large-scale synoptic setup calls for a ridge in the jet stream over the Eastern U.S. and the Mississippi River Valley, and an upstream trough over the Pacific Northwest. The pattern will be favorable towards warmer than normal temperatures and near-normal to slightly below normal precipitation for the start of meteorological summer. Break out the sungalsses and start taking off those pool covers.

Brian Crandall

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