ITHACA, N.Y. — After a weekend opener that brought temperatures down -11 F with a -27 F windchill at the airport, we could all use a reprieve. Thankfully, we should get one this week, as a ridge in jet stream brings some unseasonably mild temperatures to Tompkins County over the next several days, though with a fair amount of rain, and the risk of an icy glaze on the road tomorrow morning. No major storms are expected this week.

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The center of the Arctic high is now northeast of Bermuda, and being so far south from its origins has moderated the cold air within its confines. Secondly, being on the rear flank of the high’s clockwise flow means that southerly winds and warm air advection have been induced over Upstate New York. Temperatures have rebounded quite strongly since the bitter cold snap of Thursday-Saturday, with temperatures in the lower 40s across Tompkins County this afternoon.

A clipper low will pass by to the north of Ithaca tonight and tomorrow, its core staying over Canada. However, its cold front boundary will extend through Upstate New York, and this will lead to increasing cloudiness this evening, and a mixed bag of precip tonight. Generally, expect a light rain/snow mix (<0.1″ liquid-equivalent) in the valleys and urban Ithaca, primarily after midnight but a few preceding showers possible earlier this evening.

The issue lies with the dewpoint more than the temperature – once the precip starts, it’ll come down as rain initially, as temperatures will be in the upper 30s this evening. However, the dewpoint will be in the upper 20s, which means that as the rain falls and evaporates along the way, it will cool the atmosphere immediately adjacent. As a result, some rain will freeze over, so expect some sleet and snow to mix in this evening, changing over to rain as the dewpoint rises closer to the air temp. Tomorrow morning in the 8-11 AM timeframe, the air temperature and dewpoint will both be around 32-33 F, and that will be favorable for falling rain to freeze due to cold surfaces and dense cold air near the surface – in other words, be ready for some light freezing rain tomorrow morning.

Once the front passes, however, the wintry mix should come to an end. Skies will be cloudy for the remainder of Monday, with perhaps a few brief glimpses of sun late, and highs in the mid to upper 30s. As colder air filters in Monday night, temperatures will cool off, though remain above average for this time of the year, with partly cloudy skies and lows in the low 20s.

High pressure extends over the East Coast Monday night into Tuesday morning, but a developing storm system through Canada and the Western Great Lakes will amplify southerly winds between it and the high. This will result in a rather breezy day, 15-25 MPH with 30-40 MPH wind gusts. However, being out of the south, temperatures will climb to well above normal, mid 40s for highs. Rain begins to moves in during the afternoon Tuesday, and hangs around through the evening, though overall amounts should be light, around 0.1″. The front falls apart between the low to the north and a broken connection to the Lower Mississippi River Valley, as its southern branch detaches and becomes its own storm system. Showers will taper off after midnight, leaving cloudy skies and lows in the lower 30s.

Wednesday will be a mild and relatively peaceful day meteorologically, with partly to mostly cloudy skies and highs in the lower 40s. That storm system over the lower Mississippi will move ENE towards the Great Lakes during the day and night Wednesday, and its warm front should enter the area by Thursday morning. Expect an evening low in the lower 30s, with increasing clouds, south winds, and a couple of rain showers after midnight as temperatures climb into the upper 30s towards morning.

Thursday is looking like a washout of a day as the storm system slows down and eventually passes over Ontario on an ENE trek Thursday night. Expect a grey, breezy day with periods of light to moderate rain and highs near 50, as Tompkins will be in the warm sector of the low during the middle of the day. More sporadic rain showers will continue Thursday night with overcast skies and lows in the upper 30s.

Friday sees the cold front of the low pass through, though it won’t exactly be a plunge in temperature. Winds will be out of the west, with a few rain showers, cloudy skies and highs in the mid 40s. Friday night will see a scattered batch of rain and snow showers as cooler air enters the region, with lows in the upper 20s.

A few lake-enhanced showers will be possible next Saturday, with mostly cloudy skies and seasonable highs in the mid 30s. Dry conditions and lows in the low 20s are expected Saturday night, and highs near 40 with partly cloudy skies are on tap for next Sunday.

Graphics courtesy of the NOAA Climate Prediction Center.

Extended Outlook

Looking into the middle of the month and your Valentine’s Day plans, the outlook is for a continued jet stream ridge of milder air over the Great Lakes and Northeast, and an upstream jet stream trough over the West Coast. Pacific Ocean moisture (also called “Pineapple Express” events or atmospheric rivers) may result in enhanced rainfall over the Desert Southwest, which will then truck along the jet stream across much of the continental U.S. For Ithaca specifically, expect warmer and slightly wetter than normal conditions for the middle of February. If we have any further cold snaps this year, they don’t appear to be anytime soon.

Brian Crandall

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