ITHACA, N.Y. — In winter, one’s attire generally consists of warm coats, scarves and hats. In summer, the choices are more like loose tees, shorts and sun dresses. In spring, you get maximum versatility because the weather can swing from winter-like to summer-like and back within a matter of hours. That is the story of this week ahead, as from highest highs to lowest lows we can expect a 50°F temperature difference. Things will settle near to slightly above normal by weekend.

Your Weekly Weather

Hopefully most of you had a chance to get out and enjoy last week’s unseasonably warm and dry weather. Temperatures have moderated behind an area of low pressure that passed north of Tompkins County on Friday, and following a brief respite Saturday, system number two is working its way into the region. This second low is following a fairly similar path as Friday’s, with the core passing to the northwest of Ithaca, keeping the Southern Tier in its warm sector during the time of passage – the first volley of rain earlier this morning was the warm front ushering in the warm sector of the counterclockwise-rotating low. Temperatures across the area are running in the mid and upper 50s, a few degrees warmer than normal for the end of March.

However, there will be a second round of rain moving into Tompkins County late this afternoon and into the early evening as the core of the low passes Ithaca’s longitude and the cold front announces the entrance of the cold sector on the backside of the low. A few embedded weak thunderstorms are possible with this next volley as well as another one-tenth to one-quarter inch of rain.

The bigger story will be the persistent strong northwesterly winds that will pick up later this evening behind the low – through the night, a near constant 15-25 MPH northwest breeze is to be expected, with wind gusts exceeding 40 MPH in urban Ithaca, and 45-50 MPH possible on the exposed hilltops. The National Weather Service’s Binghamton office has issued a wind advisory from 6 PM this evening to 9 AM tomorrow morning, and as usual with a strong wind event, secure loose or light outdoor objects or move them indoors, and try not to park under any tree limbs that could snap and make for a rough Monday morning. Otherwise, plan for overcast skies tonight, heavier rains tapering off to lighter showers by 7 PM, and a few rain showers overnight, changing over to light snow showers after midnight with lows in the lower 30s.

Monday will be cold and blustery, with gusting winds steadily winding down as the day progresses. Near-overcast skies at morning will also break up to partly cloudy skies by lunch, and mostly clear skies by sunset as high pressure builds from the southwest. With the gusty northwest winds mixing the atmospheric column, temperatures will only warm up modestly, topping out in the mid and upper 40s. Monday night will be cold but quiet, with mostly clear skies and light winds turning to the south as the high shifts southeast of Ithaca and Tompkins County. Lows will be in the low 30s.

Tuesday is probably the best day of the week to run your errands or do work outdoors. On the backside of the clockwise-circulating high and enhances by a counterclockwise-spinning low to the west, strong southerly winds will being temperatures into the upper 60s with sunny skies. Tuesday night will see clouds build in ahead of the next storm system, with partly cloudy skies turning overcast by sunrise, and lows in the upper 40s.

Wednesday will be a stormy day as the extended trough from the low drapes across the country, from the low’s core in Canada do the Gulf Coast. This will allow some deeper moisture to flow up the frontal trough and provide heavier rains to the Southern Tier. Wednesday morning will be overcast and have lighter, more patchy rain showers ahead of the front. But as the cold front draws closer, that will transition to a heavier, steadier rain for the afternoon hours. Highs will be in the upper 50s with rainfall amounts during the day of one-quarter to one-half of an inch. The rain will break up a little bit during the evening with perhaps another tenth of an inch before midnight, and this will transition to snow showers after midnight, with lows in the low 30s.

For the sake of putting on your radars, wary readers, multiple forecast models show atmospheric dynamics favorable to the development of a significant snowband on the immediate backside of the front east of Tompkins County and possible including it, so a significant snowfall event (a few inches or more) during the early morning hours Thursday is possible but not a certainty at this time. Keep an eye on the forecast over the next couple of days.

Thursday will be a frigid day to ring in the month of April. A frontal trough of this size means an enormous amount of Arctic air will plunge into the eastern third of the country, with the rain-snow line all the way down to Memphis and Charlotte in the models. A strong northwest wind will keep temperatures in the mid 30s for highs, with mostly cloudy skies and lake-enhanced snow showers persisting through the day. Thursday night will see a few lingering snow showers as the atmosphere dries out, and a very cold night with lows around 20°F.

Friday will remain cold as the deep trough of polar air slowly migrates eastward. The air will be more stable so it will be sunnier, but highs will once again be in the mid 30s. Friday night will begin to see more temperate air make its way into the region as the trough of cold continues to move eastward, with partly cloudy skies overnight and lows in the mid 20s.

The weekend will be milder and quieter as high pressure once again builds in from the southwest, providing stable, warmer air. Saturday will be partly cloudy with seasonable highs in the low 50s, and Sunday will be partly cloudy and slightly warmer, in the mid 50s. Overnight lows will be in the upper 30s with partly to mostly cloudy skies.

Graphics courtesy of the NOAA Climate Prediction Center.

Extended Outlook

Looking ahead into the second week of April, after the late week cold snap, the high pressure system building in for next weekend will allow the upstream jet stream ridge to make its way eastward, providing modest warmer-than-normal conditions, as well as dry continental air that will result in below-normal precipitation. The West Coast and most of Alaska will be stuck under a deep trough in the jet stream further upstream. Longer-range models suggest this ridge will continue to migrate further eastward during the month, portending a warm and dry mid-April with the greatest anomalies over the lower Mississippi River Valley and Texas.

Brian Crandall

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