Good Thursday morning!
An unusual storm track through the St. Lawrence River Valley puts our snowpack at jeopardy as warmth and rain take over Friday. Strong wind gusts may also leave some in the dark with possible power outages. Plus, there’s a flood threat on area rivers. Let’s break it down.
First up, a quiet Thursday. Before all that action, high pressure still rules all day long. We’re mostly sunny throughout the morning, with gradually increasing and thickening clouds by this afternoon. The temp warms to about 40° with a light south wind of 5-10 mph. Tonight, the temp will drop into the upper 20s to low 30s, just as the rain gets started.
Between 10 PM and midnight, rain spreads from south to north as a warm front enters the picture ahead of the low. The actual low moves from the Upper Ohio River Valley towards the St. Lawrence River Valley, putting us on the rainy (as opposed to snowy) side. This poses many problems.
Initially, until around 3-5 AM, some pockets of freezing rain and icing are possible, especially in northern New Hampshire, east-central and northeast Vermont, plus the St. Lawrence River Valley. Icy buildup should generally be less than 0.10″, and by daybreak, plain rain takes over. The temp skyrockets throughout the day into the upper 40s to low and even mid 50s.
Rain is steadiest early to mid-morning. By late morning into early afternoon, rain tapers to scattered showers. But at this point, a low-level jet enters the picture. Southeast wind gusts of up to 50 mph rush down along the western and northern side of our mountain ranges, breaking limbs and lines possibly leaving some in the dark with scattered outages.
Friday night into Saturday, scattered rain continues, moderate at times. Around 0.75″ to 1.5″ of rain falls, combined, however, with an extra 1-3″ of water thanks to mountain snowmelt. That all rushes into our rivers, creeks and streams…many of which have ice on top. Ice jams and potential flooding should be on all of our minds. Even when the rain stops falling, there may be a delayed response as the water works its way down in elevation.
Saturday, a cold front sweeps through. The temp will fall from the 40s in the morning, gradually through the day into the 20s. Rain will wrap up, but changes to snow as it does, with some upslope snow showers of a dusting to 1-2″ possible along western and northern mountain slopes, up to peaks.
From there, quieter weather again takes hold through Christmas. The temp maxes out in the upper 20s to low 30s daily, with a mix of sun and clouds. A few Santa-approved, festive flurries or light snow showers are possible Christmas Eve.
Have a phenomenal day!
-Skytracker Meteorologist Amanda Thibault