ITHACA, N.Y. — Much concern has been raised about the lack of precipitation and the ongoing regional drought, but some measure of relief is likely over the next few days as a lumbering, moisture-laden storm system brings some liquid sunshine to Ithaca and Tompkins County, with a good soaking inch of rain likely, and welcome for replenished parched water tables. The second half of the week will be on the warm side of normal with generally sunny conditions.

Your Weekly Weather

It’s an unsettled Sunday, with mostly cloudy conditions giving way to an incoming squall line of showers and thunderstorms moving in from the southwest. A couple of the embedded cells have received Severe Thunderstorm Warnings for gusty winds, so do be careful late this afternoon and ride this out indoors if you can.

On the large scale, high pressure over the Atlantic Ocean has provided relatively stable if hot conditions over the past few days, but an incoming storm system is moving in from Ohio River Valley to Tompkins’ southwest, and that large storm system will slow down as it trudges across the Northeast Monday and Tuesday.

Let’s do the bad news first; if you have outdoor plans the next couple of days, you might want to postpone them unless they involve being all wet. On the bright side, however, this is a welcome rain that will put some work into reducing our precipitation deficit, and lessening the severity of our regional drought.

For the rest of your Sunday, other than the incoming squall line that will make its presence known later this afternoon, expect mostly cloudy skies with a few other scattered showers and thunderstorms in the area through sunset, with highs in the mid 80s. Tonight will be near-overcast as the storm system moves in. Plan for periods of rain, perhaps a few rumbles of thunder, with lows in the mid 60s.

Monday will be a wet day, with showers and thunderstorms all day long and cloudy skies. There will likely be some breaks in the rain over the course of the day, but they will not last too long. Highs will be around 80. Through sunset Monday, expect 0.5″ of rain, though locally higher amounts are certain possible in communities where a thunderstorm’s downpours make an appearance. Monday night will see less numerous showers with the loss of daytime heating and as the axis of moister air shifts eastward, but it will still be unsettled and you’ll want an umbrella if heading out. Skies will be mostly cloudy with lows in the mid 60s.

By Tuesday, the storm system will have moved east of Ithaca, but as it’s moving slowly and still has access to ample moisture, both already present in the warm moist air and oceanic flow, the rain will continue. Tuesday looks more likely to have some breaks of sun in the mix, and it will feel quite muggy as the periods of sun are frequently interrupted by showers and thunderstorms. Highs will be around 80. New rainfall amounts will be in the 0.25-0.50″ range. The rain does wind down Tuesday night as light westerly flow kicks in behind the low’s frontal trough; showers come to an end by midnight with partly cloudy skies to follow and lows in the mid 60s.

Broad and rather diffuse high pressure builds in for Wednesday. There will be some possibility for an isolated pop-up shower or thunderstorm in the later afternoon or early evening, but most communities should stay dry. It will be mostly sunny with highs in the mid 80s. Wednesday night will host a few passing clouds and lows in the low 60s.

Thursday will see the high shift eastward, which will channel slightly warmer air on the rear western flank of its clockwise circulation. It will be a tad on the humid side with dewpoints in the low 60s, but mostly sunny with highs in the upper 80s. Thursday night will be another pleasant night with mostly clear skies and lows in the low 60s.

Models indicate a weak SW-NE oriented frontal trough passing through Tompkins County Friday, though the timing is still inconsistent between various model runs. General consensus (the model blend) is for a late morning passage, with pop-up shower and thunderstorms in the PM hours due to localized instability and daytime heating. Skies will be partly cloudy with highs in the mid 80s. Friday night will see showers ending a little after sunset, with partly cloudy skies and lows in the upper 50s.

Taking a gander at the models for next weekend, generally expecting warm and dry conditions. Expect mid to upper 80s both Saturday and Sunday with mostly sunny skies, and overnight lows in the mid 60s.

Graphics courtesy of the NOAA Climate Prediction Center

Extended Outlook

Looking ahead into the start of September, the large-scale weather pattern favors two pronounced jet stream ridges over the Pacific Northwest and Atlantic Coast, with Pacific flow into Mexico and Texas, which will provide moisture to an area struggling with its own drought issues. The combination of moist air (which takes more solar energy to warm) and displacement of air to the northwest and east will allow for cooler-than-normal temperatures in the South-Central U.S. Upstate New York sees some of that moisture advected northeastward along with the warm air, so warmer and slightly wetter than normal conditions are expected for the period.

Brian Crandall

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