DAYS 1-5 (JULY 5-9)
While the clouds cleared out better than I expected yesterday, the marine layer held strong, and that has lead to a cloudier morning than I expected today. Also, the lead trough in a 1-2-punch from the northwest carries quite a bit of cloudiness above the stratus we have over much of the region now, so this will keep us on the cloudier side at least into if not through mid morning until enough of the mid level cloudiness goes by to allow the sun to work on the stratus layer below. Also, the expected early morning showers near the NH Seacoast are right in that region as of the writing of this update (8AM), and a few may clip far northeastern MA as well before exiting to sea. Eventually, we get into sunshine and it warms up rather quickly, but there will be a boundary setting up as we try to set up a land breeze against what still wants to be an onshore flow. This boundary is going to be our first potential trigger point for showers and thunderstorms during the afternoon. This may take place anywhere along the boundary, but probably only a couple or a few cells, so we’ll have to visually watch the clouds and of course the radar and now-cast the event if and when it unfolds a bit later. The second kicker is a short wave / cold front coming down from northern New England later in the day and this evening. Still favoring southern, especially southeastern NH, and eastern, especially northeastern MA for the greatest storm potential. These storms may appear in cluster form and have the potential for wind damage, both straight line and (lower risk of) tornadic. Wind damage should be isolated, but could be significant where it occurs. And of course hail and frequent lightning may accompany any storms today. Things settle down later tonight and then a little push of high pressure from eastern Canada comes for Monday, a day of northerly to easterly wind but with dry weather. Then as the high slips off to the southeast, the wind will turn more southeasterly on Tuesday, which may feature more cloudiness as a warm front approaches. A shower may occur near this boundary but activity should be fairly limited on Tuesday as the boundary lifts very slowly through the region. This will set up a more humid and warmer day Wednesday, with a warm front passing and a cold front approaching – a set-up for possible thunderstorms. This boundary will weaken but may still be in the area Thursday for continued humid weather and an additional risk of a shower or storm in some locations.
TODAY: Cloudy into or through mid morning then becoming partly sunny. Isolated to scattered showers and thunderstorms favoring eastern MA mid to late afternoon, and potential thunderstorms in southeastern NH and northeastern MA by early evening. Humid. Highs 80-87, but cooler along some coastal areas. Wind variable under 10 MPH this morning, E 5-15 MPH immediate coast and SW 5-15 MPH elsewhere midday on, but variable and gusty winds, potentially strong, are possible near and in any storms.
TONIGHT: Variably cloudy evening with possible showers and thunderstorms, favoring southeastern NH and eastern MA. Partly cloudy overnight. Patchy fog. Humid. Lows 60-67. Wind NW to N up to 10 MPH, gusty near any storms.
MONDAY: Mostly sunny. Highs 73-80, coolest coast. Wind N to E 5-15 MPH.
MONDAY: Partly cloudy. Lows 60-67. Wind SE under 10 MPH.
TUESDAY: Increasing clouds. Slight risk of a shower. Highs 75-82, coolest coast. Wind SE 5-15 MPH.
TUESDAY NIGHT: Mostly cloudy. Slight risk of a shower or thunderstorm. More humid. Lows 63-70. Wind S up to 10 MPH.
WEDNESDAY: Partly sunny. Chance of showers and thunderstorms, especially during the afternoon and evening. Humid. Highs 82-89, cooler some South Coast locations. Wind SW 5-15 MPH.
WEDNESDAY NIGHT: Partly cloudy. Risk of a shower or thunderstorm early. Patchy fog. Humid. Lows 65-72. Wind SW up to 10 MPH.
THURSDAY: Partly cloudy. Risk of a shower or thunderstorm, mainly in the afternoon. Humid. Highs 85-92, cooler South Coast and Cape Cod. Wind SW 5-15 MPH.
DAYS 6-10 (JULY 10-14)
A piece of upper level high pressure will decrease the shower and thunderstorm risk but briefly spike the heat in the region on July 10, potentially the hottest day of the summer so far. Watching the potential for some increased moisture in the region during the July 11-12 weekend translating to less heat, but higher humidity and a great shower/t-storm risk. Drier air follows for July 13-14 based on current timing.
DAYS 11-15 (JULY 15-19)
The ridge center re-forms well to the west, leaving this area in a northwesterly air flow, which features a couple opportunities for showers and thunderstorms from passing disturbance, and temperatures generally near to slightly above normal.