Brief warm up ahead but winter is not over yet
Conrad Straden–The Tech
Tonight’s system will bring some more mixed precipitation, similar to Tuesday night. Light rain breaks out in the early evening, changing to sleet around midnight, and then to snow through Friday morning. The exact timing of changeovers are still uncertain, and a few degrees difference in temperature could mean we end up with no accumulation or several inches of snow. The bulk of the precipitation will move out by Friday morning; however, a light drizzle or mist will linger most of the day. Saturday will warm up, but it will remain cloudy and damp. Sunday will be stellar, with temps near 50°F and lots of sunshine. Looking ahead into next week, some models are showing extreme warmth with temperatures near 70°F, but I would take those with a grain of salt. The sea surface temperature in Boston Harbor is 36°F right now which is much colder than usual. This means that with a sea breeze (or any wind with an easterly component), we will remain much cooler than inland. For instance, it might be nearing 70°F in Worcester yet only in the 40s here. This is a typical early spring phenomenon in Boston. Sometimes this temperature difference can occur rapidly — called a backdoor front, it can drop temperatures by 20 degrees in just minutes. For next week, temperatures will likely stay in the 50s instead.
While meteorological winter is now over, that doesn’t mean we are out of the woods yet for wintry weather. Next week the Polar Vortex (PV) is forecast to split, causing a Sudden Stratospheric Warming event. In simple terms, this means that the upper layers of the atmosphere will experience rapid warming, which causes cold air in the troposphere to move southward into the mid-latitudes. The effects are generally delayed a few weeks, which means we will not see the effects until late March and early April. While it might be too late for sustained wintry weather, it could still mean more below-average days, delaying the nicer weather. The PV previously split back in late November, which is why December temperatures were below average. Having more than one PV split in one winter season is fairly rare, occurring about once per decade.
In other news, this Sunday is the beginning of Daylight Savings, which means clocks “spring” forward an hour. What this means is we will lose an hour of sleep Saturday night, but gain an hour of daylight in the evening. Sunset on Sunday will be at 6:42 p.m., while sunrise will be at 7:08 a.m.
Today: Rain Showers Late. High around 38°F (3°C). Northeast winds 10–15 mph with gusts to 25 mph.
Tonight: Mixed Precipitation. Low around 32°F (0°C). Northeast winds 10–15 mph with gusts to 30 mph.
Friday: Snow Early. High around 35°F (2°C) and overnight low around 33°F (1°C). Northeast winds 10–15 mph with gusts to 25 mph.
Saturday: Cloudy. High around 46°F (8°C) and overnight low around 45°F (7°C). Southwest winds 10–15 mph with gusts to 40 mph.
Sunday: Sunny. High around 55°F (13°C) and overnight low around 35°F (2°C). West winds 5–10 mph with gusts to 15 mph.