Jul 11, 2016 11:53 PM
NH1 First Alert Weather: Heat and humidity strike back in NH
NH1 Chief Meteorologist
On Tuesday...a surface high center quickly retreats offshore to our south. Return flow of warmer air will introduce some areas of mid and high clouds to the area during the afternoon. Westerly winds should keep the seabreeze at bay with high temperatures in the 80s. A few 90 degree readings are possible over southern New Hampshire. Dewpoints should remain below 60F Tuesday and should be the last relatively comfortable day this work week. A few passing clouds Tuesday night otherwise a dry night with patchy late night valley fog and stratus once again. Lows will range from the upper 50s to mid 60s.
With high pressure off the coast Wednesday through Friday under a building upper level ridge aloft...a southwest flow will bring warming temperatures and increasing humidity to the region. The threat of showers and thunderstorms will also increase each day as a cold front approaches slowly from the west. Wednesday should be mainly dry across the area with highs in the Lwr 90's and dewpoints in the mid 60's.
As the front gets closer Thursday...the greatest threat will be in western areas and the mountains during the day Thursday but spreading eastward Thursday night. The weak front should cross the region Thursday night into Friday morning but temperatures and humidities will remain rather high during the day Friday. Both Thursday & Friday will see highs around the 90 degree mark or higher across the interior. Dewpoints will be in the 60's, near 70 making the heat index feel 95-100 to end the week.
Behind the front...Saturday`s temperatures should be cooler...but a secondary front could bring another threat of showers and thunderstorms for Saturday afternoon...depending on the timing. Models differ considerably on timing with some more progressive than others. For now...have kept the area mainly dry for Sunday but less confidence than previous forecasts. After the system moves east...dry and cooler weather is expected early next week.