ITHACA, N.Y. — If you’re chaperoning the kiddos on Halloween night, make sure you have an umbrella handy – it and much of the week ahead will be drenched with rain. On the bright side, at least all of that precipitation will be liquid, and you can get away with a light jacket as the young ones go door to door. Small blessings folks.
— NWS (@NWS) October 27, 2018
Last week was a cold one. Temperatures haven’t broken 50 °F since last Tuesday, rather unusual given that the average high temperature this time of the year is in the mid 50s. Traces of snow were reported on a few days, but nothing measurable (greater than 0.1″) has been picked up at the airport or at the Cornell/Northeast Regional Climate Center (NRCC)’s weather station on Game Farm Road just yet.
According to data from the NRCC, the first 0.1″ of snow in Ithaca has an average arrival date of October 19th. Problem is, precipitation tends to vary a lot from year to year. If we go through the past thirty or so years of data, only six years had October snowfalls of 0.1″ or greater (1988, 1990, 1993, 2008, 2009, 2016) and of those, four (1988, 1993, 2009, and 2016) were 1″ or greater. In fact, here’s the Voice’s 2016 article on the October snow of that year, exactly 1.0″ on the 27th. October 1988 gets the distinction of being the snowiest October in the entire 125 years of records, thanks to 6.5″ on the 22nd-23rd of that year.
It looks like we should make it out of this October snowless, but it’s definitely been a rainy week, with measurable rain (>0.01″) on four of the past seven days. Unfortunately, that pattern will continue, albeit with some milder, more seasonable temperatures.
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The coastal system that started off the weekend drenching is now well out to sea, but a fast-loving area of low pressure is crossing through the Northeast Sunday night and into Canada, meaning that the wet, cloudy conditions have yet to depart. With that cloud cover, lows Sunday night should stay around 40 °F, so don’t expect any snow flakes.
Monday won’t be a washout, but it will be cloudy and cool, with some scattered showers behind that low. Highs will top out in the upper 40s in Ithaca proper, with mid 40s in the outlying towns. The northwest winds coming in behind that low are going to make feel a few degrees cooler, so bundle up.
Thankfully, it will start to clear out Monday night – the remaining showers dissipate and the clouds start to break up. It will be mostly cloudy and dry by Tuesday morning. Lows will be in the upper 30s.
An area of high pressure over the Southern Appalachians will steadily build in for Tuesday, and in a welcome change of pace, it should be a pleasant fall day. The clockwise flow of the system will promote warm air advection (the scientific way of saying heat carried along on the flow of air), so temperatures will climb into the mid 50s under partly cloudy skies. If you have to things outdoors this week, this is the day to do it. Tuesday night will see clouds thicken ahead of the next system, but the eastward-moving high will keep the milder air flowing, so lows will only fall back to the mid 40s.
Wednesday/Halloween will be another rainy day as a cold front slowly works its way in from the west, ushering in a solid, steady band of by early afternoon (late morning for those of you west of Ithaca). The front will stall out and hold in place, so the rain will stick around. A steady flow of mild air from the southwest ahead of the cold front will push highs into the upper 50s to near 60 °F.
Let’s make this clear for you costume planners – Halloween night will be rainy, alternating between light and moderate periods. Plan accordingly. Expect mid 50s for trick-or-treating, and overnight lows will be in the low 50s.
If that weather’s not bad enough, a developing low pressure area from the lower Mississippi River Valley will phase in and ride along the front. That will create a surge of mild but very moist air, and with the unstable air of the front, it will generate heavy rain for much of Thursday. There is some concern of flooding, depending on length of rainfall and intensity, so keep an eye out for updates.
For Thursday, expect rain, heavy at times. Highs will be in the upper 50s. Thursday night, the low should continue to lift northeastward, and the front will slowly grind eastward, allowing the rain to start winding down. Lows will be in the upper 40s Thursday night with frequent showers, and Friday will be mostly cloudy with scattered showers and a high in the upper 50s. It will remain mostly cloudy Friday night, with lows around 40 °F as cold air starts to seep in behind the front.
The weekend’s looking unsettled as the front lingers on the East Coast and a weaker low pressure area along the jet stream sends a pulse of instability through our region, leading to more cloudiness and showers as cooler temperatures settle in. Saturday will be most cloudy, with scattered showers and in the low 50s, Saturday night will be quiet and bottom out in the upper 30s, and some sun will make an appearance on Sunday with highs in the low 50s. Overall, it’s seasonable temperatures for the week, but much wetter than usual.
Looking ahead towards the first half of November and Veteran’s Day Weekend, it’s a mixed bag. On the bright side, it will likely be warmer than normal, as a pronounced trough in the jet stream settles into the middle third of the continent, and the east and west coasts fall under a a pair of ridges that will channel warmer air northward. On the not so bright side, the eastern two-thirds of the country and also likely to see wetter than normal conditions as disturbances track along the jet, south from Canada, east through the plains states, and out via the Great Lakes. Given it’s still early in the cold season, it’s better than heavy snow.