Mostly Dry Spring Days Until Thursday Night & Friday Rain...and Possibly...Snow!

LKN_FRONTS_BOSDMA (25)A northeast wind blowing across New England in the spring often brings clouds, drizzle and showers.  Although that was the case during the first half of Monday, a decided trend toward drying and brightening was pronounced Monday afternoon and a sign of what’s to come.  The reason our First Alert Team has been advertising mostly dry and even relatively fair days of weather Tuesday through Thursday is because the persistent northeast wind has blown long enough to carry drier air out of Canada, and the result should continue to be intervals of sunshine between periodic bubbling clouds, making for a fair sky, with the heartiest clouds producing a few sprinkles at times but nothing of substantial impact.  Even limited sun provides a relatively strong spring sun angle, meaning temperatures inland could reach or exceed 60 degrees Tuesday and Wednesday afternoon, while ocean water temperatures in the 40s will keep daytime highs near the coast in the 50s both days.  A large chunk of high-altitude atmospheric energy moves east from the Great Lakes into the Northeast from Thursday into Friday and this is expected to prompt storm development near or directly over Southern New England, meaning rain develops Thursday evening and night and continues through Friday, along with an increasing and gusty east wind, especially near the coast.  NBCUFS_Snow
The story becomes more complicated in that Thursday night and Friday timeframe when looking at the temperatures through the lowest few thousand feet of the atmosphere over New England – cold enough that snow becomes a possibility for some!  Right now our thinking is snow will initially mix in Thursday night for the Green Mountains, Berkshires and Monadnock Region, then may spread into the higher terrain of Worcester County on Friday and at least some flakes may mix in during Friday for the suburbs north and west of Boston!  It’s honestly too early with this situation to speak with any confidence on snow amounts – our exclusive NBC Boston and NECN Forecast System is predicting amounts of two to six inches in the hills of the deep interior, with even higher amounts in mountains, but with a warm ground leading into the event and marginal air temperatures, our team of meteorologists certainly takes a cue from the very guidance we’ve built ourselves, but we also step carefully into a slew of variables that can significantly impact how much snow actually accumulates.  Regardless, the windswept rain for many will slow Friday travel for much of New England and wind gusts may exceed 45 mph at the coast.  The weekend brings improvement with a recovering temperature into the 50s and early next week our exclusive 10-day forecast features high temperatures into the 60s for at least a couple of days to start the week.

Cool, Lots of Clouds...But Not Too Wet Most of This Week

LKN_FRONTS_BOSDMA (24)Last week, New England benefitted from being stalled under fair weather between a slow-moving storm to our east, and another to our west.  This week, we flip the script – the weather pattern remains slow-moving but we’re close enough to a storm over the Great Lakes and Ohio Valley that clouds, cool air and occasional raindrops will be in the forecast for days to come.  Monday morning showers stretched from Southern VT to Southeast MA, with other clusters of showers over southwest New England.  Most of the morning showers melt away in favor of cloud cover and a cool breeze Monday midday and afternoon, with the persistent northeast wind off the 40-45° ocean water making it hard for afternoon air temperatures to exceed 50° in most eastern New England communities and in the 50s in Western and Northern New England.  A northerly and northeast wind seems unlikely to break in the days ahead, meaning while at times breaks of sun will increase when the wind becomes more northerly and a little less off the ocean, the majority of the week will deliver more clouds than sun.  With the sprawling storm center slowly drifting across the Eastern U.S. to our west and not directly overhead, that really limits how much rain is expected to fall, with total rain amounts over the entire week through Thursday evening only expected to be less than 1/10 of an inch!  So, outdoor plans look decent on most days this week, as long as clouds and cool air are part of the expectation.  The bigger change is expected Thursday night through Friday when the energy driving the storm system to our west finally draws close enough to swing a storm center nearby and delivers steady and soaking rain on Friday, with enough cool air that some snow may mix in for interior, higher-terrain communities!  For most of us, if this soaking rain comes together it would be welcome news to a depleted New England water table that’s been pushed all the way into drought for some of VT and Western NH, though the highest rainfall totals of around an inch would likely fall in the Southern half of New England, where abnormally dry conditions fall short of drought classification.  Saturday likely brings dry conditions but our First Alert Team isn’t excited about significantly warmer air, then a chance of showers builds again by later Sunday as afternoon high temperatures finally return above 55 degrees.  The good news looking at our exclusive 10-day forecast is next week doesn’t look as cool, or as cloudy…but with a jet stream “trough” – or dip in the storm steering jet stream winds aloft – over the Northeast U.S., we’re likely to find multiple rounds of clouds and showers sliding through particularly during the first half of the week.

Prolonged Fair Weather to Prolonged Showers Starting Sunday

LKN_FRONTS_BOSDMA (23)A very slow-moving weather pattern across North America and the North Atlantic Ocean has been benefitting New England much of this week, and while the benefits only increase through Saturday, it looks like this same slow motion weather progression will mean an extended period of showers next week.  For now, each day has been progressively milder with cooling sea breezes kicking up in an otherwise light prevailing wind and our First Alert Team expects more of the same Thursday, Friday and Saturday, with even our coastal communities a bit warmer each day before sea breezes kick up each late morning through afternoon.  By Saturday, inland communities will likely rise all the way into the 70s under a fair sky and light southwest wind!  All of this dry weather continues to elevate both the pollen count and brush fire danger across New England, with the ongoing drought in Central and Eastern Vermont into Western New Hampshire not improving and even expanding a bit in the newest national drought update, released by the government and university consortium on this Thursday morning.  Well to the west of New England, a persistent jet stream trough – a dip in the jet stream – has been churning a sluggish storm system east with recurring areas of rain and thunder from the Mississippi River Valley and Midwest into the Tennessee Valley.  The jet stream is the fast river of air that flows high in the sky, steering storm systems and separating cool air to the north from warmth to the south, so to have a large jet stream trough means disturbances continue collecting in the same location, along with relatively cool air.  This jet stream trough will set up over the Eastern United States starting Saturday, opening the door here in New England to arriving rain middle to late morning Sunday, with showers continuing through the remainder of Sunday…but also sticking around, off and on, through all of next week!  Until the jet stream trough aloft breaks down and allows storminess to move away – which may not happen even into next weekend at the end of our exclusive 10-day forecast – the chance of showers remains elevated.  This certainly doesn’t mean it’ll rain nonstop and, in fact, it’s possible we don’t see very heavy rainfall totals when it’s all added up, but the chance of showers looks rather high on any given day next week into next weekend.

Slow-Moving Weather Pattern Means Dry This Week, Showery Next Week

LKN_FRONTS_BOSDMA (22)Our stretch of dry weather continues for a few more days in New England, though like previous days, Wednesday will bring a duel of sun and clouds in our sky.  Sunshine starting Thursday morning gives way to building, bubbling clouds developing in a combination of increased moisture and cool air aloft, on the western periphery of a large storm stalled over the Canadian Maritimes.  Our surface wind is also influenced by the big storm to our east, gently blowing from the northeast, off the ocean to keep coastal communities in the 50s at the warmest time of Wednesday while we cross 60 degrees inland.  The continued dry air with a light breeze means our pollen count remains high through the rest of the week, with maple the latest newcomer to the pollen scene, and brush fire danger remains elevated, necessitating caution with any outdoor burning.  Each day through Saturday gets progressively better as the large storm over the North Atlantic slowly weakens while nudging farther away, allowing for clouds to give way to sun Thursday and a fair sky Friday and Saturday.  With the onshore wind flow slowly weakening each day, coastal communities should be able to exceed 60 degrees at least briefly Friday and for a longer period of time Saturday, while inland communities make a run to 70 degrees both of those afternoons.  All signs point to a major change in the weather pattern for New England starting on Sunday, so enjoy the splendid weather while it lasts.  Interestingly, the global weather pattern isn’t changing much – a slow-moving weather pattern featuring some sprawling storm systems, but the big difference for us is instead of being stuck between storms, we’ll be stuck under one.  This should mean an increased chance of showers not only Sunday by mid to late morning, moving in from west to east and lasting the day, but an increased chance of showers on each day next week, all the way through the end of the week in our exclusive First Alert 10-day forecast.  As you might expect, increased clouds and showers – along with a likely weak onshore wind flow – will keep temperatures down, and on a few days (Monday chief among them) our team may need to lower the temperature forecast even a bit more as we get closer, depending on the amount of clouds and strength of the onshore wind.