Amherst, MA 01003 Weather

What Has Changed

Gale Warnings have begun to be replaced by Small Craft Advisories for near shore southern waters, and this will continue over the next 24 hours.

Key Messages

- Cooler day on Friday with plenty of sun and diminishing wind.

- Prolonged stretch of dry weather with seasonable temperatures prevails this weekend into much of next week.

Discussion

KEY MESSAGE 1...Cooler day on Friday with plenty of sun and diminishing wind.

Friday will continue the stretch of beautiful Fall weather for the region as we say goodbye to any influence from Subtropical Storm Josephine, replaced by building high pressure encroaching from the north. The weakening gradient will mean less of that northerly wind through the day. After winds initially start out breezy, gusting 15- 25 mph they'll end the day much lighter. Overnight in fact, under high pressure winds will become calm under clear skies, so lows were trended toward the colder MOS guidance, in the upper 20s to low 30s. This, after a cooler day on Friday after cold advection kicks in aloft; 925mb temps drop from 9C today to 0-1C on Friday leading to highs in the 50s.

KEY MESSAGE 2...Prolonged stretch of dry weather with seasonable temperatures prevails this weekend into much of next week.

A prolonged stretch of dry but pleasant autumn weather is in store for Southern New England spanning this weekend then continuing into a large portion of the upcoming workweek. Expansive area of surface high pressure of around 1030-1034 mb will remain anchored across the Northeast and mid-Atlantic region, with mild days and cool nights with strong diurnal temperature ranges. About the only nuanced difference is that a cold front sags southward Monday night into Tuesday with a cooler northern-stream airmass filtering southward; but the front is moisture-starved and only seems capable of producing some enhanced cloudiness Monday evening and a cooldown in high temps moving into next week. Mildest days look to be this weekend with temperatures in the mid to upper 60s, but there could be a shot at 70 degrees with several days of dry weather serving as a mild feedback mechanism for overachieving maximum temps over guidance. Highs then cool off into the mid 50s to low 60s for early next week as the cooler lower-level airmass works it way in (925 mb temps dip to around +2 to +4C), only modifying toward mid to late next week.

Aviation

Forecaster Confidence Levels...

Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent.

00Z TAF Update:

Tonight: High confidence.

VFR, with FEW-SCT stratocu as cool front sags south from NH/VT early tonight. North winds around 8-12 kt, though around 12-16 kt with gusts to 25-30 kt for Cape and Islands.

Friday...High confidence.