ITHACA, N.Y. — For those asking for a reprieve from the rain, heat and humidity that’s defined the past month or so, you’re in luck today – areas of high pressure will generally prevail Monday and for the second half of the week, leading to more comfortable conditions and dry conditions. However, the risk of heavy rain Tuesday night will give already wary flood-hit communities yet another thing to worry about.
Rainfall amounts over last 24 hours for New York State. Two distinct bulls eye clearly visible…first over western NY where 5-9 inches have fallen leading to devastating flooding in some areas and then 1-3″ over the Catskills into the western Mohawk Valley. pic.twitter.com/7LEQ2ap27L
— NWS Albany (@NWSAlbany) August 14, 2018
Woof. It’s been a week for the Southern Tier. After an unusually wet July, the first half of August continued the extreme wet weather pattern, with warm, moisture-laden air driven from the south combining with an unstable atmosphere resulting from a cutoff low pressure area. The cutoff low was removed from jet stream flow, and as a result it barely moved over a period of several days before finally being pushed out and exiting northeastward.
The results of this pattern have been nothing short of devastating for some of out Southern Tier neighbors. After monthly records last month, towns in the Finger Lakes and the Tiers were not capable of absorbing the additional 5 to 9 inches of rain that feel over just a few hours as pop-up storms and downpours trained over parts of the region (multiple cells passive over one place). Hector, just over the western county line, picked up 11.53″ in two days. When the ground is saturated, the water has to go somewhere, and the result of that was flash flooding.
The town of Lodi, just a little to our north in Seneca County, was among the hardest hit. Vehicles were swept away in the floodwaters, roads and bridges were washed out (supports and all), and a number of homes and businesses have been damaged or destroyed. The Ithaca Fire Department completed water rescues of at least twenty people from parts of the Hector and Valois areas. Thankfully, no fatalities have been reported.
Tompkins County was very fortunate that the storms did not train over towns here. The airport picked up a total of 1.40″ of rain last week. The Game Farm Road weather station in Dryden received 1.47″. Co-Op observers in Newfield and Caroline picked up 2.59″ and 0.78″ respectively.
As the cleanup continues following the destructive floods to the north and west, the weather should be generally favorable this week, but meteorologists and emergency response teams will be keeping a close eye on the potential for a renewed flooding risk Tuesday night.
Your Weekly Weather
At this moment, things are looking okay. A cool, quiet Sunday night will lead to a fairly pleasant day Monday, as high pressure moves eastward through New England and the Canadian Maritimes. With drier air than we’ve been seeing (though perhaps still a bit humid with dewpoints in the low 60s), temperatures should top out in the upper 70s and low 80s under partly cloudy skies. Monday night should be similarly quiet, with lows around 60 °F and a light south breeze, with clouds building up as we get closer to daybreak Tuesday.
The concern this week is the result of a strong low pressure area that will be approaching from the Ohio River Valley on Tuesday. The first line of precipitation will pass through during the afternoon with a warm front ahead of the low. This will not only create an initial round of rain, but a surge of very moist air from the south. Moist air allows for significant downpours when the atmosphere is unstable and rain develops, and the atmosphere will be very unstable as the cold front tracks into the area as the low heads into Canada. Potentially, a squall line with strong thunderstorms may develop.
This particular low is tracking with a low-level flank of the jet stream, which means it will move quickly, but that there will also be a wind threat with the rain threat. A half inch to an inch of rain is likely, two inches in isolated cases, with winds of 20 MPH gusting to 40 MPH with some storms. With saturated soils, that could make trees to come down, so be cautious if you’re outdoors Tuesday night.
For Tuesday, it will be a dry start, but rain will spread over the region by early afternoon. Temperatures will reach the mid and upper 70s before the thick clouds and rain stall out further warming. Rain showers and the occasional thunderstorm will continue into Tuesday night, with lows in the mid 60s. The rain should begin to wind down Wednesday morning as the cold front passes through and the air starts to stabilize. The rest of Wednesday will be mostly cloudy and breezy, with a few lingering showers and highs in the low to mid 70s.
As Canadian high pressure builds in from the west, Wednesday night through Friday night is looking quiet, comfortable and seasonably warm for later summer. Wednesday night will be partly cloudy and in the mid 50s, Thursday will be sunny and in the upper 70s, and Thursday night will be mostly clear with temperatures in the mid 50s. Friday will be a tad warmer as the high shifts east, topping out in the low 80s with sunny skies. Friday night will be a nice evening to hit the town, with only a few passing clouds and lows in the upper 50s.
For those with weekend plans, things are looking good for Saturday, but the next pulse of instability and rain may make its way in for Friday, though timing is a bit uncertain this far out. Expect mostly sunny skies for Saturday and early Sunday with highs in the low to mid 80s, and lows Saturday night in the low 60s.
Don’t count summer out just yer. A pronounced ridge of high pressure and heat is being picked up in multiple forecasting models for the end of the month, and it could be a very warm Labor Day holiday weekend. In fact, the NOAA Climate Prediction Center has highlighted the Northeastern U.S. for the small possibility of excessive heat, meaning temperatures well above normal such that they pose a risk to health and safety. Precipitation amounted are looking to be close to normal for the end of the month and start of September.