-- Discussion containing changed information from previous version are highlighted. --
937
FXUS61 KGYX 142230
AFDGYX

Area Forecast Discussion
National Weather Service Gray ME
630 PM EDT Fri Jun 14 2024

.SYNOPSIS...
Cold front moves offshore tonight with cooler and
drier air arriving for the weekend. After another seasonable day
Monday...temperatures and humidity will build through the
middle of the week with an extended period of very hot and
humid conditions expected through the week.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
-- Changed Discussion --
Have cleaned up PoPs a bit for the next few hours based on
latest radar imagery and CAM output. A broken line of low-topped
thunderstorms, at times showing brief supercell characteristics,
has developed in a corridor from near Plymouth NH to Waterville
ME. Instability and deep shear continues to be sufficient for a
few strong storms with gusty winds being the main threats.
Cannot rule out a svr storm or two. This threat will continue
into the evening before the bulk of the activity moves off the
coast in advance of a cold front.

Previously...

Scattered strong to severe storms continue for the next few
hours before the front pushes offshore this evening. The best
chance for these looks to actually be across central Maine and
New Hampshire, where temps were able to warm more with more
sunshine and less shower activity earlier in the day. Southern
NH appears to have a lower chance for storms than earlier
thinking after being worked over more by morning showers, but
temps are still warming back up again and there will likely
still be some storms later this afternoon. Damaging winds and
large hail continue to look like the main threats with these
storms.

The front pushes offshore this evening, with clearing
overnight. The front slows down in the Gulf of Maine overnight,
which slows the clearing closer to the coast, so some clouds may
linger through daybreak tomorrow. Father north, cooler and
drier air begins to work in overnight, with lows falling to near
50 degrees.
-- End Changed Discussion --

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
High pressure moves in from the northwest during the daytime
tomorrow, bringing dry conditions and seasonable temps. A
northwesterly breeze also helps to keep the seabreeze away,
allowing temps to warm into the mid to upper 70s south of the
mountains. Overall, a pleasant and comfortable day is expected
for tomorrow, offering a great day to get air conditioners in
ahead of next week`s heat.

Tomorrow night looks seasonably cool, with lows falling into
the 40s in most spots. Mid to upper 30s are likely across the
northern valleys, and some patchy frost can`t be ruled out in
some of the most sheltered valleys. The high crests over New
England tomorrow night, providing clear skies and light winds
overnight.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
     
-- Changed Discussion --
Record Heat Forecast Confidence Continues to Increase...

Overview: Amplifying 500mb ridge axis across the Eastern CONUS will
continue to build through the week before cresting across our region
by mid-week with extremely anomalous  height fields. Potential
suppression of the amplified ridge towards the end of the
forecast period as shortwave troughs move across Northern New
England bringing the threat for thunderstorms, cloud cover and a
cooling trend.

Impacts: Multiple days of heat indices in excess of 95 to 100F
beginning Tuesday likely continuing through the end of the week. The
potential exists for heat indices in excess of 105F especially over
southern NH and SW ME.  The Merrimack Valley is of particular
concern.

Forecast Details: Sunday - Surface ridge will be centered over the
area with a perfect June day expected as dewpoints remain in
the 50s under mostly sunny skies.

Monday - Surface warm front pushes through the area as Mid-Atlantic
heat doom amplifies northward.  A few showers are possible along the
warm front along with increased cloud cover and the beginning upward
trend in humidity but overall seasonable weather is expected.

Tuesday - Quick ramp up in temperatures and humidity as 500mb
heights increase to 596 dam along with 850 temps of 26C. This will
allow for heat index values to surge into the 90s and the first day
that heat headlines might be needed.

Wednesday - Thursday things get worse with some impressive 500mb
height anomalies over us as the heat dome becomes centered across
the NE CONUS.  Reforecast Ensemble Means are near record values in
all ensemble camps, thus record highs or near record highs have high
confidence at Day 6 forecast time frame.  In addition the heat will
be building with low temps remaining in the 70s, causing
unconditioned buildings to have issues. Looks like if excessive heat
warnings are needed it will be in this time-frame.

Friday - Guidance is hinting at a slight suppression of the heat
dome as the area looks to be in the ring of fire as 500mb shortwaves
will be riding over the ridge bringing the chance for thunderstorms,
most likely severe in nature based off climatology break down of
ridge patterns.
-- End Changed Discussion --

&&

.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
-- Changed Discussion --
Short Term...Scattered showers and brief TSRA continue into the
evening hours across central and coastal terminals for the next
few hours. VFR conditions prevail otherwise, and return in full
by late this evening. VFR conditions then prevail through
tomorrow night.

Long Term...No aviation impacts are expected Sunday through Monday
with VFR conditions in dry weather.  The issue moving into the week
will be the building heat and possible impacts to crews.
-- End Changed Discussion --

&&

.MARINE...
Short Term...Marginal SCA conditions continue through this
evening. A cold front moves through the waters the evening,
with scattered thunderstorms during the early evening hours.
High pressure builds across the waters for the weekend, bringing
fair conditions.

Long Term...This period will be dominated by surface high pressure
allowing seas to remain below SCA conditions. Offshore to parallel
flow will be the dominate wind pattern through next week. Expect
seas to be in the 2 to 3 feet range.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...None.
NH...None.
MARINE...Small Craft Advisory until 8 PM EDT this evening for ANZ150-
     152-154.

&&

$$


NEAR TERM UPDATE...Ekster