ITHACA, N.Y. — Last week, it was noted that the high pressure area sitting over us would prevent Florence from affecting our region. In the immediate case, that was correct; the worst of the storm has been confined to the Carolinas. However, its remnant circulation and rains are still churning, and as the high pressure recedes, the remains of Florence will be upon us. Grab your umbrellas and rain boots.

Weather Recap

We seem to doing a redux for remnant tropical cyclones. At about this time last week, it was the remains of Tropical Storm Gordon that were affecting the Southern Tier. At this posthumous stage, the winds aren’t an issue, and fears of a storm surge are not high on the list for anxious Ithacans. However, tropical moisture tends creates an atmosphere with a high “precipitable water content” (PWC/PWAT), meaning the air is laden with water vapor, the rains it brings are more intense, and if the system is slow-moving, prolonged with the potential of flooding.

In the case of Gordon, the rains associated with its aftermath, which had merged with a frontal system heading northeastward, left about 1.88″ of liquid sunshine in the rain gauges at the Ithaca-Tompkins airport, which was then followed by a resurgent ridge of high pressure and the rather hot and humid conditions that prevailed for most of the past week. According to the Northeast Regional Climate Center, September is running well above normal temperature-wise, though it looks like that should moderate somewhat over the week ahead, with rather comfortable and pleasant conditions once the remnants of Florence have swept through.

Graphic courtesy of NWS Binghamton.

Your Weekly Weather

At the moment, things are dry, thanks to the high pressure areas located off the coast near Maine and the Canadian Maritimes. However, its presence at this point is fairly tenuous. Its clockwise circulation, along with a low pressure area over Canada, create an environment conducive to allowing the remnants of Florence to make their way over the Appalachians and through the Northeast before heading out into the Atlantic again (redevelopment is not expected).

There is some concern of flooding with the remnants of Florence. The soil in many communities is already saturated from weeks of high rainfall amounts, so it won’t take much to create significant runoff from heavy rain. Fortunately, the atmosphere won’t be too unstable, so thunderstorms will be sparse, and weak where they do form. But Tompkins County should expect another soaking rain, a multi-hour moderate to heavy rain event that will leave 2-3″ in most areas, with the higher amounts in elevated locations that can force uplift and wring more moisture out of the tropical airmass. Keep an eye out Monday night and Tuesday morning for any flash flood warnings in areas near streams or creeks, which may wash over and into adjacent roads and neighborhoods.

For your Monday, expect a dry start, with some high cirrus clouds overhead, thickening as the day progresses. Temperatures will top out in the mid to upper 70s before the rains move in, generally in the 2-5 PM period, a little sooner for those south and west of Ithaca and later in that time frame for those north and east of Ithaca,  Monday night will be a wet one, you’ll want to have an umbrella if out and about. Rain, moderate to heavy at times, will persist to around daybreak Tuesday morning, with a couple inches likely. Lows will be in the upper 60s.

Tuesday will start to see the rains taper off as the system advances eastward, but lingering scattered showers will bring periods of additional rain during the day, heavy at times. The rain should start dissipating and the clouds will start breaking up late in the day. Highs will be in the mid 70s. Tuesday night, expect mostly cloudy skies becoming partly cloudy by dawn, with lows around 60 °F.

Things should be quiet for the rest of the week as Canadian high pressure builds back into the region. Temperatures should be seasonable as the week continues. For Wednesday, expect a pleasant day, with partly cloudy skies, comfortable humidity, and temperatures in the low 70s. Wednesday night will be cool and quiet, with just a few passing clouds and lows around 50 °F.

Thursday will be a tad warmer, but otherwise much the same. The forecast is for just a few passing clouds and high temperatures in the mid 70s. Thursday night should be a bit milder thanks to southerly winds, with partly cloudy skies and lows in the low 60s.

Friday comes with a moderate chance of rain from a weak system passing to our south, but generally, it should be partly sunny with highs in the mid to upper 70s. Friday night will be mostly cloudy with a few scattered rain showers, and lows in the upper 50s.

Next weekend, Cornell Homecoming for all those Big Red readers out there, should be fairly pleasant for tailgating, watching the football team play against Yale, celebrating 150 years of classes and keeping the restaurants downtown busy. Saturday is looking sunny with highs in the upper 60s, Saturday night mostly cloudy in the mid 50s, and Sunday will be partly cloudy with highs around 70 °F – a picture perfect weekend to ring in the start of autumn on Saturday.

Graphic courtesy of the NOAA Climate Prediction Center.

Extended Outlook

Taking the long view, the NOAA Climate Prediction Center is expecting near normal temperatures for the remainder of September, with near normal precipitation amounts. We’ll be on the cusp of a persistent ridge of heat over the Southeastern United States, which may push into and recede from the area depending on the state of the atmosphere on a given day. Temperatures in late September typically top out in the mid to upper 60s with lows in the mid to upper 40s, so we’re starting to get into jacket weather in the mornings, but otherwise it wouldn’t be an unpleasant way to wrap up the month.

Brian Crandall

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