ITHACA, N.Y. — For those who like the idea of ‘staycations’, if you have the next week off it’ll be a rather pleasant experience, as initial unsettled weather gives way to sunnier skies with comfortable temperatures and humidity for the second half of the week. For the rest of us, we’ll have to enjoy it after hours and between errands. (When I was growing up, vacation time meant painting the house or redoing the driveway, and to this day I have an aversion to taking time off).
Your Weekly Weather
At present an area of low pressure is located well to the south just off the coast of the Carolinas. In its counterclockwise flow is a tap of warm, moist and unstable air being fed by the Gulf of Mexico, passing over the Deep South, into the Ohio River Valley and turning eastward through Pennsylvania, with the Twin Tiers on the edge of its flow.
At present, the weather is fairly pleasant, with partly to mostly cloudy skies and dry conditions. The risk is how moist and unstable the local column of atmosphere can become. Right now, the state’s Mesonet system shows most local observation stations with dewpoints comfortably in the middle to upper 50s. If more warm, moist can be ushered in from the southwest, and raise that dewpoint to the mid 60s, then we could be at substantial risk for some strong to severe thunderstorms, as a more moist atmosphere allows hot surface air to rise more rapidly and feed into thunderstorm development, and there is ample energy for severe storms with damaging winds and flash flooding.
This could be a situation where Tompkins County lucks out in timing. A shortwave (pulse of instability) pinwheeling around a Canadian low pressure area is likely to push in from the northwest, but by the time it triggers thunderstorm development in the Southern Tier, it’ll be close to sunset, after the prime period for diurnal heating and influx of energy into the atmosphere. So keep that in mind for the rest of your Sunday; clouds will build and highs will top out in the mid 80s, with the chance, particularly later in the evening, for some shower and thunderstorms, some of which could be strong. This will continue through the overnight as the shortwave draws closer, but without the daytime heating they will be more sparse, with a few showers and storms, mostly cloudy skies and lows in the low 60s.
Monday will see that short wave sweep through, which will provide an unstable environment throughout the day, with the best chances for showers and storms coinciding with the period of maximum surface heating, 10 AM to 7 PM with a peak in the mid to late afternoon. Some of these could be strong, with somewhat less moisture available tomorrow, but atmospheric dynamics more favorable to strong winds. Outside of potential rains, it’ll be mostly cloudy and a touch on the humid side with highs in the upper 70s. The departure of the short wave and loss of daytime heating will result in calmer conditions overnight, with a few scattered showers before midnight and partly cloudy skies with lows in the upper 50s.
Behind the short wave and the low to the north, a fairly expansive area of high pressure will begin to build in from the upper Great Lakes and this will stabilize the atmosphere and induce northwesterly flow that will result in drier, cooler conditions for Tuesday. A weak isolated shower or two may pop up, but most areas will remain dry, with partly cloudy skies and highs in the low 70s. Tuesday night will see clearing skies as the high pressure system edges closer, with mostly clear skies and lows in the low 50s.
Wednesday will be a gorgeous day, with generous sunshine and temperatures a few degrees below normal due to the clockwise flow around the high, which will remain over the Western Great Lakes. Highs will be in the low 70s with comfortable humidity. Wednesday night will be clear with lows in the upper 40s.
Thursday will be a little warmer as the core of the high approaches the Southern Tier and the northerly wind slackens. The atmosphere will remain stable, with mostly sunny skies and highs in the mid 70s. Thursday night will see a few passing clouds and lows in the low 50s.
Friday sees temperatures climb higher, likely back into the lower 80s as the high shifts further east and southerly flow kicks in on the backside of its clockwise flow. Clouds will increase during the day as a new storm system to the north will drape a frontal boundary southward, likely to sweep across Upstate New York Friday night, setting off a round of showers and thunderstorms after sunset. Outside of the storms, it will be mostly cloudy with lows in the low 60s.
Next weekend is looking seasonably warm, with scattered showers and thunderstorms Saturday behind the front and highs in the lower 80s, tapering off Saturday night with mostly cloudy skies and lows in the upper 50s, and mid 70s and partly cloudy, dry conditions for Sunday.
Looking into the last week of the month, a jet stream ridge will provide hotter and drier than normal conditions to much of the Western United States (which is extremely bad, given the historic drought and growing fears of a devastating wildfire season), while a downstream trough will adjust the prevailing storm tracks to favor near-normal temperatures with above-normal precipitation over the Midwest. Further downstream, the East Coast will see slightly above normal precipitation and near to slightly above normal temperatures as it sits along the edge of the next ridge. So all in all, an unexciting weather pattern locally, which is to be expected in the summer months as the temperature gradient between the tropics and the poles isn’t as steep as it is in the winter.