Higher Summits Forecast

A lot to go over today, so one step at a time. Bermuda high pressure that has been dominating the weather this past week will be pushed a bit south today as a trough approaches from the west. Although the high is weakening, it will once again be hot and humid today with the record to beat on the summit being 65F which seems within reach as models are indicating a tie or a near tie of this daily record high. The only limiting factor that may prevent this from occurring though will be from a low to our north that will be dragging a weak cold front down from the northwest today. This cold front will then stall out as a frontal boundary just north of the summits and will act as a focus for clouds and possible shower or thunderstorm activity this afternoon into the overnight hours. Overnight into early Friday, this boundary will then lift north as a warm front as a low approaches from the west. The low lifting this front northward won’t affect the state until later this weekend but first we have to get through Hurricane Earl. As the warm front exits early Friday, a brief gap will occur in the weather allowing for a bit of clearing but this won’t last long as high clouds start in from the south from Earl. Clouds will thicken and lower during the day and showers and possible thunderstorms may approach for the afternoon but most of the activity will occur overnight Friday into Saturday morning. The overall consensus in the models this morning is to keep the center of the storm offshore enough to keep the heaviest rain and highest winds well to our east. But there are a few variables that may track this differently. The main factor will be the timing of the trough to the west but also the timing of the surface low with this trough expected on Sunday. If these slow and the storm shifts to the left of the track cone by as little as 2 degrees, this could be a direct hit. If the storm shifts to the right more, we could get almost nothing out of it. But so far, everything is tracking correctly and should, at least for NH and the summit, be a glancing blow. But before Earl causes concern, it will be the hazy and poor air conditions today and early Friday that will be more noteworthy. Conditions will be poor enough that the NH Dept of Environmental Services has declared an air quality action day for the summits. As a result of the poor air quality, it is advised that sensitive individuals like children, the elderly, or those with heart or lung conditions limit activities requiring prolonged or heavy exertion; like hiking. But even healthy individuals should take caution and may feel the ill effects of the poor air. And with such limited views with the haze and intermittent fog, when the frontal boundary sets up and showers or thunderstorms start popping up, seeing cells approaching will be limited limiting the amount of time you might have to seek shelter.

Today:

In and out of the clouds under increasingly cloudy skies w/ a slight chance of afternoon showers or thunderstorms.

Highs: mid 60s°F

Wind: W 35-50 mph decreasing to 20-35 mph

Tonight:

Mostly in the clouds under mostly cloudy skies w/ a slight chance of showers or thunderstorms.

Lows: mid 50s°F

Wind: W 20-35 mph

Tomorrow:

In and out of the clouds under mostly cloudy skies w/ a slight chance of showers and thunderstorms.

Highs: lower 60s°F

Wind: W shifting SE 20-35 mph decreasing to 10-25 mph