DAYS 1-5 (AUGUST 10-14)
A still-active pattern allows plenty of fair weather time between tantrums. One such tantrum is coming in the form of a passing low pressure system tonight. This is the system I’ve been eyeing for a couple days for a brief potential severe storm / tornado threat for the South Coast. It does look like a limited-coverge, short-lived threat for the South Coast region later this evening to the early overnight hours as low pressure passes right over that region. A trough in advance of this system can help kick off a few showers and thunderstorms late today with the help of daytime heating, but expecting only isolated coverage with that and north of I-90. This area will see only limited activity with the nighttime round – mostly just a swath of showers. It’s nearer the South Coast where downpours / thunderstorms / and brief damaging winds can occur. That system is outta here by early Friday, and we’ll have a sun/cloud day with drier air, though comfortably warm, but a gusty breeze. Then while the weekend is looking pretty decent overall, we do have one disturbance to keep an eye on, racing our way via the Great Lakes, later Saturday to early Sunday. The questions regarding the thunderstorm threat with this: Timing? Coverage? Global guidance has been a bit faster, while the shorter range (just on the edge of its time frame) is slower. Global guidance has already proven to be a bit too fast at this range the last couple systems, but not by much. Without over-thinking this and with a couple days to fine-tune it, I’m going with a “Saturday night event” from west to east, in the form of scattered showers and t-storms. Does an additional disturbance prolong the shower / thunderstorm chance on Sunday mainly south of I-90? We will have to re-evaluate that. While a bubble of high pressure brings fair weather at worst by later Sunday (if timing is slower) and at best all of Sunday (with faster timing), we see this continue at least into Monday before we look to the west for the approach of the next disturbance, which for now I think doesn’t get here that day, other than some advanced cloudiness.
TODAY: Sun dominant first half of day, then variably cloudy afternoon. Late-day thunderstorms possible west of I-495. Evening showers eastern CT to RI. Highs 80-87, a bit cooler South Coast. Dew point 60+. Wind S 5-15 MPH becoming variable around 10 MPH by evening.
TONIGHT: Mostly cloudy. Showers likely. Downpours and thunderstorms possible mostly south of I-90 which may have the ability to produce isolated tornadoes. Areas of fog forming. Lows 62-69. Dew point 60+. Wind variable 5-15 MPH, can be briefly strong and gusty near any downpours and thunderstorms mainly south of I-90.
FRIDAY: Sun and passing clouds. Highs 78-85. Dew point near 60. Wind W 5-15 MPH.
FRIDAY NIGHT: Partly cloudy. Patchy ground fog. Lows 62-69. Dew point lower 60s. Wind SW under 10 MPH.
SATURDAY: Partly sunny. Late-day shower or thunderstorm possible southwestern NH / central MA / eastern CT. Highs 80-87. Dew point 60+. Wind SW 5-15 MPH.
SATURDAY NIGHT: Variably cloudy. A shower or thunderstorm possible. Lows 62-69. Dew point near 60. Wind SW 5-15 MPH.
SUNDAY: Partly sunny. Chance of a shower or thunderstorm, especially in the morning. Highs 78-85. Dew point near 60. Wind W 5-15 MPH.
SUNDAY NIGHT: Mostly clear. Lows 57-64. Dew point under 55. Wind W up to 10 MPH.
MONDAY: Sun followed by clouds. Highs 77-84. Dew point rising back to near 60. Wind variable to S up to 10 MPH.
DAYS 6-10 (AUGUST 15-19)
A generally zonal flow pattern is expected, disturbances passing by with a couple shower and thunderstorm chances – most likely August 15 & 17. Temperatures near to slightly above normal.
DAYS 11-15 (AUGUST 20-24)
A weaker westerly flow and a little more high pressure domination overall reduces shower/storm opportunities and allows for a little more late summer heat potential during this period.