NWS Gray, Maine Area Forecast Discussion

FXUS61 KGYX 061936

Area Forecast Discussion
National Weather Service Gray ME
336 PM EDT Mon Jul 6 2020

Highs pressure over the waters tonight shifts east on Tuesday
and settles SE of the maritimes foe Wednesday. Scattered
thunderstorms are expected on Wednesday as a front drops out of
Quebec. High pressure builds in for the end of the week with the


For the most part it should be a quiet night with mainly clear
skies and light winds winds. This will allow temps to fall
quickly, and should be the coolest night we`ve seen in awhile,
and will likely see for the next week ahead. Lows range from
around 50 in the mtns to uppers to around 60 in srn NH and on
the coast. Models aren not in good agreement on whether stratus
forms or not tonight, but given how quickly fog/stratus over
the Gulf of ME is moving S, will play it down, but if it does
happen will likely be late. Do thing that some patch fog is
possible is some sots, given the good cooling tonight.


Tue looks to be dry, but will likely see strong enuf S pres grad
flow that the marine air will fairly well inland, especially
into the ME. Also, expecting a fair amount of cirrus thru the
day. Highs range from the upper 60s to low 70s in the coast to
around 80 inland areas of NH.


The week ahead features very hot temperatures with a chance for
shower and thunderstorms, a typical July pattern.

Taking a hemispheric view the polar jet has retreated northwards
into the Canadian arctic leaving most of the CONUS under strong
ridging with just the occasional short wave to disturb it. The
most notable portion of the polar view is in fact a large ridge
of high pressure over the western Arctic. While notable in its
own right for near record setting temperatures in Siberia that`s
also the feature that will need to break down to allow more
typical circumpolar flow and allow our own CONUS ridge to move
on at the end of the week.

Starting Wednesday we`ll begin to see the surface high build into
our area. To make room for it, first we`ll need a shortwave dropping
south out of Quebec to make way for it. This will likely touch
off showers and thunderstorms. Expect the most storm coverage
in the mountains where the greatest instability lies. Storm
coverage will be widespread across the entire region, however
the greatest upper support is to the east, leaving the greatest
threat for Severe weather extending through central Maine. In
addition to severe weather, forecast soundings suggest storm
motion could be fairly slow leading to heavy rain.

As we move into Thursday and Friday high pressure and a very humid
airmass takes hold. Guidance continues to put dewpoints into the low
70s across the southern portion of the region, and with even a
midpoint of high temperatures in the 90s this will put the heat
index near 100 in the Merrimack valley. While Thursday has been
trending as the warmest day, feel it is likely that Friday will be
just as warm if not hotter as the prolonged flow and inability to
cool down or mix overnight will help to keep the humid air around.
Thus have gone on the upper edge of guidance for Friday

For the weekend, widespread rainfall is expected. A low develops
off Cape Hatteras on Thursday and moves up the eastern seaboard.
While the exact track may vary the overall consensus is for
widespread rainfall and have introduced likely pops for
Saturday. While this time period is too far out for exact QPF
amounts, the strong southerly flow suggests a potential
atmospheric river event with a maxima in rainfall in the
foothills of the White mountains.


Short Term...Some radiation fog at almost all terminals
tonight, but will likely come in later than previous night. VFR
expected Tuesday into Tuesday eve, with some flight
restrictions possible later Tue night as rain and low cigs move

Long Term...Scattered afternoon thunderstorms may briefly impact all
terminals on wednesday. High pressure builds in for the end of the


Short Term...Seas/winds blo SCA criteria.

Long Term...High pressure will build in for the middle of the week. By
the end of the week a low will begin to move up the coast, crossing
the waters on Friday night with SCA conditions likely.




LONG TERM...Curtis

NWS GYX Office Area Forecast Discussion