ITHACA, N.Y. — For those of you looking to get back outdoors after last week’s cold snap, there will plenty of opportunities this week as high pressure remains in control through Thursday with comfortable temperatures ranging from the upper 50s Monday to upper 60s for Wednesday and Thursday. Some light if persistent rain showers are likely to work in for the second half of the week, though nothing drenching is expected, and highs will cool slightly but remain comfortably in the 60s through the weekend.
Weather Recap
March 2021 is in the record books as a rather warm and dry months as far as Marches in the land of gorges go. At 35.6°F, average temperatures were 3°F above normal for the month. In terms of seasonal ranking, though, that’s not very impressive – according to the Northeast Regional Climate Center, March 2021 is the 32nd warmest out of about 122 valid years of records for the Ithaca area, March is a highly variable month thanks to the strong gradient between the warming lower latitude and still frigid polar regions, and it’s not uncommon for the temperature to be five degrees above or below normal depending on whether a jet stream trough or ridge dominates this longitude of the globe. A year hasn’t been this close to the climatological March normal since 2013.
Across the region, the story was much the same – every single one of the 35 first-order weather stations were above normal for the month of March, and five had top ten warmest Marches, with Erie, Pennsylvania the most abnormal with its fifth-warmest March on record. The only sizable area recording below normal values was in and around the Whiteface Mountain observational sites (lodge and summit) in the Adirondacks. This was to be expected as a ridge in the jet stream dominated the East Coast for much of the month, allowing milder air to surge northward.
On the precipitation side, March was also a fairly dry and snowless month for Tompkins County. The NRCC’s Game Farm Road site recorded 1.19″ of liquid and liquid-equivalent precip for the month of March, well below the average of 2.64″. In fact, 1.19″ makes for the tenth-driest March in the NRCC’s Ithaca-area records. The snow situation wasn’t any better – 1.9″ of snow were recorded at the Game Farm Road station in March, much less than the 11.7″ usually seen during the month.
Regionally, there was a little more variation in precipitation, with 27 of the 35 first-order weather stations recording drier-than-normal Marches, and Erie, Rochester and Syracuse recording top-ten driest Marches. However, all 35 stations were below normal for snowfall. This is a problem because much of the Lake Ontario watershed is now in abnormally dry or mild drought conditions, and it gets harder to make up precipitation deficits as the air temperature warms because evaporation is more effective when it’s warmer outside. Upstate New York needs a wet spring to avoid potential water supply and brush fire issues this summer.
As for the week ahead, it’ll be generally pleasant for outdoor activity, but with only a few rain showers likely later in the week, the parched soil conditions to the north and west of Ithaca are likely to get worse and expand in areal impact.
Your Weekly Weather
A sunny, seasonably mild day is wrapping up across the Finger Lakes this Sunday, as high pressure over the Deep South continues to press into the region. The storm system that came through last week is up in Atlantic Canada at this time and behind the low, the counterclockwise flow remains northwesterly, but like two gears turning against each other, the flow is actually picking up the westerly flow of a clockwise-circulating high over Mississippi and Alabama, providing a moderating effect to local temperatures. A second high over the Canadian Shield will reinforce the northwesterly winds.
With the loss of daytime heating, it’ll be a clear and seasonably cool night ahead for Ithaca and Tompkins County. Expect moonlit skies with lows in the mid 30s in the city of Ithaca and areas next to Cayuga Lake (and the moderating effect the water lapping its shores provides), and lower 30s in the outlying areas.
Monday should be a mild and sunny day, though you’ll still want to have a light jacket handy. Most areas will top out in the upper 50s with a light northwest wind. A few fair weather cumulus might pop up in the afternoon and early evening, but these will wither away with the loss of diurnal heating and a mostly clear night is once again expected for Tompkins County Monday night, with lows in the mid 30s.
The high pressure to the south stays largely in place for Tuesday. Temperatures will climb slightly higher as the wind calms and less agitation of the air allows the air to more efficiently absorb that heat energy created with the plentiful sunshine to be present during the day. Expect another day of mostly clear, sunny skies, with temperatures making it into the lower 60s for highs. The ridge in the jet stream will allow for a weak short wave (pulse of instability) to travel through the region Tuesday evening and night, but with little moisture available this will only produce a few isolated light rain showers along with partly to mostly cloudy skies. Lows Tuesday night will be in the low 40s.
The southern high shifts eastward into the Atlantic for Wednesday, and a developing storm system over the Great Plains will enhance the southerly flow of the high’s rear (western) flank. The northern high, however, will keep the atmosphere relatively stable while warmer air is advected (thermally transferred) northward on southerly winds. Partly cloudy skies will decrease in coverage as the day progresses, and it will be pleasantly warm with highs in the upper 60s. Wednesday night will see partly cloudy skies and a mild overnight low in the mid 40s.
Rather unusually for this region’s “Storm Country” reputation, but the storm over the Great Plains doesn’t do the usual “strengthen and move northeast” as we typically see; in fact, models show that it will weaken, drift north-northwest and eventually be dragged northeastward into Canada by a trough to the north. The southerly flow between the low and the Atlantic Ocean high will continue Thursday, providing for another day with partly sunny skies and highs in the mid to upper 60s. Southerly flow will tap into some of the moisture dredged up by the system and let it flow it into the Southern Tier Thursday night, which will create mostly cloudy skies and a chance for some light rain showers after 2 AM, but most areas will remain dry with lows in the upper 40s.
Friday’s a little tricky because the models show a cutoff low developing in the Western Great Lakes behind the previous storm system, and that may drive eastward and impact Ithaca’s weather next weekend. The motion and intensity is not yet consistent in model runs, so there’s greater uncertainty than normal with the forecast 4-7 days out. What is likely is that shortwaves will also pass around the edge of the jet stream ridge and tap into the moisture advected in Thursday night to create unsettled conditions for Friday and the weekend, though nothing that looks like a washout. It will be mostly cloudy with a chance for some light to moderate rain showers Friday, with the clouds limiting the warming somewhat and capping highs in the lower 60s. Friday night will see mostly cloudy skies with a chance for rain showers and lows in the mid to upper 40s.
With concerns about the potential cutoff low’s movement noted, right now the weekend is looking a little unsettled and on the warm side of normal. Plan for mostly cloudy skies Saturday with the chance for a few rain showers and highs in the low 60s. Saturday night will see mostly cloudy skies and diminishing showers with a low in the mid 40s. Sunday is looking dry and partly cloudy with highs in the low to mid 60s.
Extended Outlook
Looking ahead into mid-April, medium-range models are consistently in a broad ridge with a sharp peak in the ridge (high amplitude) over the Great Lakes and Northeast, indicating warmer-than-normal temperatures are likely for the period. Overall dry continental air will be balanced out with southerly flow from less stable mid-Atlantic and Southeastern U.S. coastal areas, resulting in what’s expected to be near-normal precipitation amounts for the 8-14 day forecast period.