DAYS 1-5 (MAY 12-16)
A slow transition of the spring weather pattern continues over the next several days. Last week’s omega block (low West, high Plains, low East), as noted on yesterday’s blog post, transitioned to a rex block pattern (high North, low South). We’re currently under the influence of high pressure, but as we move through this week, the large scale features shift and the high slides to the east while the low to the south drifts northeastward, our way. However, there will be resistance from the high and the overall process will be quite slow to occur. This means that while we see an increase in clouds after today’s abundant sun, the clouds will struggle to thicken up into midweek, and any rain will be held at bay to our south and west as well. Finally by Thursday and Friday as we see the now broad and weaker upper low move further northeast, we’ll see a trend to a more southerly air flow and as a result more moisture with lots of clouds and increased shower chances. Neither of these days look like full on rainy “wash-out” kind of days though.
TODAY: Clouds scoot across southeastern NH / northeastern MA early on, otherwise abundant sunshine. Highs 60-67 Cape Cod / South Coast, 68-75 elsewhere. Wind W to SW 5-15 MPH.
TONIGHT: High clouds fan in from the southwest. Lows 48-55. Wind SW to variable under 10 MPH.
TUESDAY: Sun & high clouds. Highs 63-70 coast, 70-77 inland. Wind variable up to 10 MPH with coastal sea breezes.
TUESDAY NIGHT: High clouds increase. Lows 50-57. Wind SE up to 10 MPH.
WEDNESDAY: Limited sunshine / lots of clouds. Highs 60-67 coast, 67-74 inland. Wind SE up to 10 MPH.
WEDNESDAY NIGHT: Mostly cloudy. Lows 52-59. Wind SE up to 10 MPH.
THURSDAY: Mostly cloudy. Chance of showers. Highs 64-71, coolest coastal areas. Wind SE up to 10 MPH.
THURSDAY NIGHT: Mostly cloudy. Chance of showers. Lows 53-60. Wind S up to 10 MPH.
FRIDAY: Mostly cloudy. Chance of showers. Highs 63-70, coolest South Coast. Wind S 5-15 MPH.
DAYS 6-10 (MAY 17-21)
Continued slow pattern shift as upper level low pressure dominates but the core of which passes to our west then north. This starts us out in a southerly air flow which then trends more westerly. There are shower chances early in the period, the May 17-18 weekend, before a drying trend takes place. Temperatures near to slightly above normal for the period overall.
DAYS 11-15 (MAY 22-26)
Late month pattern features a broad trough of low pressure and mostly west to east flow, with a trend for more cool air from Canada – i.e., temperatures near to below normal, with mostly dry weather interrupted by brief shower chances. Memorial Day Weekend is May 24-26 as part of this expected pattern.