ITHACA, N.Y. — If you raked and bagged your leaves, here’s hoping they’re tucked away; a rather potent cold front will be coming through in the next few hours. Gusty, chilly winds will prevail for the next few days before milder, sunnier conditions return late in the week.

Your Weekly Weather

Let’s start off by noting the imminent threat coming in during the early evening hours today – a strong cold front moving in as part of a deep area lof low pressure trekking eastward over the upper Great Lakes. There’s enough energy in the atmosphere ahead of this front that thunderstorms are likely in the 5-6 PM timeframe, a little earlier west of Ithaca and a little later to the east. This front is well placed to take advantage of a lower-altitude “jet streak”, a minor branch of the jet stream, and the front will allow the jet streak’s higher winds to mix down closer to ground level.

At present, a region-wide wind advisory has been posted through 10 PM, with the possibility of wind gusts in the 40-50 MPH range on more exposed hilltops as this front blows through Tompkins County, and we’ll need to keep a close eye on those thunderstorms in the event that the squall line turns severe. The squall line generated significant wind damage in Ohio earlier, and the risk for wind damage with this rapidly-approaching line is significant.

If you have any light objects unsecured outdoors, move them into a sheltered space immediately, as they may become airborne during a high wind event; be wary of tree limbs and prepare for the possibility of intermittent power outages. If you’ll be driving a high-profile vehicle, try to adjust your driving plans to avoid this evening, and if you can’t, then proceed slowly and with great caution if you’ll be passing through areas that will leave you exposed to a strong westerly wind. Heavy rain is also likely with this front, with lighter rains ahead of the squall line. Expect one-quarter to one-half of an inch of rain, mostly in that 5-6 PM timeframe, and rapidly winding down after 7 PM.

Once the front passes through around 7 PM, winds will turn from the southwest to a more westerly direction, and it will be a breezy night, with winds in the 15-20 MPH range under mostly cloudy skies. Lows will be in the mid 30s Sunday night, but that wind will make it feel more like the upper 20s.

Monday will be something of a raw, unpleasant day to be outdoors, with breezy westerly winds, mostly cloudy skies, and highs in the mid 40s. Some lake effect snow showers will be possible to the north of Ithaca (thanks to Lake Ontario), and to the west (thanks to Lake Erie). Monday night will see the winds abate somewhat, and it will be dry and mostly cloudy to start off the night, but some rain and showers will be possible closer to morning as a weak, fast-moving short wave (pulse of instability) slides through the Southern Tier. Lows Monday night will be in the mid 30s.

Tuesday will be another cold, cloudy day as that short wave pushes through during the morning and afternoon. No accumulating snows are expected during the morning and rainfall amounts will be light, less than one-tenth of an inch. However, that short-wave will reinforce the flow of cold air, and winds will be breezy out of the northwest – highs will be in the low 40s, but it’s going to feel more like low to mid 30s. With the winds turning more northwesterly with the short wave’s passage, Tompkins County will be a better angle to receive lake effect snow showers off of lake Ontario Tuesday night, even as high pressure begins to build in from the west. A coating is possible by morning, with lows Tuesday night in the mid 20s and a wind chill that makes it feel like the mid teens.

Wednesday will be cold but dry as high pressure passes to our southwest, tapping cold air from the upper Great Lakes and advecting it into the Southern Tier on a northwesterly breeze. Highs will be in the mid 30s with decreasing clouds during the day, from mostly cloudy in the morning to a few patchy clouds by sunset. Wednesday night will be cold and partly cloudy, with lows in the low 20s.

Thursday will be a noticeable improvement as the high shifts eastward, placing us in the rear flank of its clockwise flow. Those southerly winds will warm temperatures up appreciably, while the high provides for stable air and generally partly cloudy conditions. Highs will be in the upper 40s. Thursday night will see partly to mostly cloudy skies, with lows in the mid 30s.

The winds take on a more southwesterly angle for Friday as the high becomes rather elongated, with dual maxima over the southern Appalachians and southern Atlantic coast. This will tap warmer air from the lower Mississippi River Valley, and temperatures will be well above normal, with partly cloudy skies and highs in the upper 50s. The high will continue to control our weather into the overnight, and Friday night will be partly cloudy with lows in the upper 30s.

The weekend is looking pleasant to start, although forecast models are indicating a storm system passing to our west and then our north, up and over the Southern Tier Sunday. that may result in some scattered rain showers, but we’ll miss the bulk of it according to current projections. Expect mid 50s Saturday with partly cloudy skies, partly cloudy skies Saturday night with lows in the upper 30s, and mostly cloudy with a few showers Sunday with highs in the mid 50s.

Graphics courtesy of the NOAA Climate Prediction Center.

Extended Outlook

Looking ahead to the week of Thanksgiving – and for the sake of others, please practice social distancing – it’s looking like it’ll be warmer than normal as a fairly expansive ridge in the jet stream settles in over much of the continental United States. That said, there will some slightly elevated chances for precipitation, most likely in the form of rain, during the late November period. Early indications suggest the warmer-than-normal conditions could last into early December as that ridge over the upper Midwest persists.

Brian Crandall

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