Marine Weather and Tide Forecast for Concord, NH

KEY MESSAGES
1. Warmer and more humid weather builds through the week as high pressure remains in control of the weather pattern.

2. Increasing moisture Thursday into the weekend will bring daily chances for showers and thunderstorms.

DISCUSSION
KEY MESSAGE 1 DESCRIPTION...

The Bermuda High builds westward toward the Eastern Seaboard this week, bringing warmer and more humid conditions by mid to late week. Temperatures generally reach into the mid 80s by Wednesday, with upper 80s to low 90s expected for most areas from Thursday through at least Saturday. Dew points will also be on the rise through the week, and likely begin to push 70 degrees by Thursday, and expand on Friday and the weekend.

The combination of heat and humidity likely pushes heat indices into the low to mid 90s across parts of southern New Hampshire and just back from the coast of Maine. The heat overall doesn't look like a high end event, but an extended period of multiple days with heat indices into the low to mid 90s.

Cooler temperatures likely don't arrive until early to mid week next week with a cold front. There remains a widespread time range on the possible arrival of this front anywhere from late Monday to Wednesday of next week.

KEY MESSAGE 2 DESCRIPTION...

A long wave trough over the Canadian Prairies will gradually deepen and slide east the second half of the week. Ensembles are in decent agreement that southwest flow ahead of the trough will advect deep moisture into the region with PWATs nearing 2.0 inches by Thursday. The trough axis does not cross the area through the weekend allowing for deep moisture to persist. Dew points in the upper 60s to low 70s Thursday through Saturday combined with surface heating will likely generate sufficient instability for thunderstorms during the afternoons. Ensembles are highlighting Friday and Saturday as the days with high probabilities of CAPE greater than 500 J/kg across much of the area with CAPE mainly focused over NH Thursday. Deep layer shear through the period may approach 35 kts, which will be sufficient for organized convection. The lack of a well defined surface feature for forcing and ridging just to the east suggests coverage of any showers and storms will be limited Thursday and Friday. Embedded short waves help knock the ridge down Saturday with better forcing for ascent overspreading the area. Saturday is when PoPs will climb into the 50 to 70 percent range south to north with PoPs lowering into next week. Machine Learning guidance out of CSU is highlighting potential for strong to severe storms Friday through Sunday with the highest probabilities on Saturday. It will likely take a few more model cycles to pin down the finer details on storms Friday into the weekend while there does appear some potential for torrential rainfall given the high PWATs and strong to severe storms.

AVIATION /18Z TUESDAY THROUGH SUNDAY/
Through Wednesday night: Mainly VFR. Patchy valley fog brings potential for restrictions at LEB and HIE tonight and again Wednesday night.

Outlook:

Thursday - Tuesday: Mainly VFR prevails at most terminals. A brief afternoon shower or thunderstorm is possible each day.
Nighttime valley fog will be possible each night, especially at LEB and HIE.

MARINE
High pressure continues to build over the waters and persists into Thursday with winds and seas remaining below SCA thresholds. A slow moving front approaches from the west Friday into the weekend while winds and seas remain below SCA thresholds. Mainly fair conditions prevail as high pressure remains in control of the weather pattern through the weekend, bringing a steady southwesterly flow.

GYX WATCHES/WARNINGS/ADVISORIES
ME...None.
NH...None.
MARINE...None.