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831
FXUS61 KGYX 151027
AFDGYX

Area Forecast Discussion
National Weather Service Gray ME
627 AM EDT Sat Jun 15 2024

.SYNOPSIS...
A cold front will drift south and exit the forecast area later
this morning. Behind the front an area of high pressure will
settle over the region through Sunday, bringing mild and less
humid conditions for the weekend. A warm front will move into
the region Monday followed by a stretch of very hot and humid
conditions through the week.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
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6 AM Update: Residual showers continue to shift offshore early
this morning as a cold front lags near the coast. This will be
the last of rain chances as cooler and drier air will be ushered
in behind it, as noted already inland. While some clouds will
be found across coast to start...drier air will quickly erode
them leading to mostly sunny skies.

Prev Discussion: Cyclonic flow aloft is in place as the trough
axis shifts to our east. Surface high pressure will be building
down from the Great Lakes, however gradient winds and mixing
will favor a WNW breeze around 15 to 20 mph, higher in the
mountains. Dew points will plummet into the 40s, and this
combined with some cooler temperatures in the mid 60s to mid 70s
will favor comfortable conditions.
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&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
With the surface high settling over the region overnight, the
scenario will promote clear skies allowing temperatures to
bottom out. Looking at lows in the upper 30s to mid 40s by early
Sunday morning. This will likely lead to some valley fog given
calm winds, particularly in the Connecticut River valley. The
high will drift east on Sunday with return flow, helping to
bring temperatures and dewpoints up. Looking at highs in the mid
70s for most of the region with dewpoints climbing back into
the 50s. Overall conditions will be mild, a welcome period
before the upcoming heat during the work week.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
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Record Heat Forecast Confidence Continues to Increase. Few
changes to the long term. Hot but mainly dry forecast.

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.

RECORD HIGHS FOR JUNE 19:
Concord-98, 1995
Augusta-98, 1995
Portland-94, 1995

RECORD HIGHS FOR JUNE 20:
Concord-98, 1993
Augusta-95, 1953
Portland-93, 2020
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&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
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Short Term...Looking at RH values dropping into the 35-45%
level this afternoon, supporting clear skies and VFR conditions.
Winds will increase with gusts around 20kt for most terminals,
but by tonight with high pressure building overhead it will drop
off.

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.
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&&

.MARINE...
Short Term...At the time of this issuance a cold front boundary was
sinking south towards the coast while a 1010mb surface low lingered
off the Midcoast. Despite the nearby proximity of the low, buoy obs
show seas are mostly in the 2-4 ft range across the coastal waters,
and winds are in the 5-10kt range. The low is pulling away from the
area as the cold front sinks south. A period of 10 to 20kt winds
possible behind the front this afternoon. Surface high pressure will
build across the waters for the weekend, bringing fair conditions
into Sunday. Both ahead of, and behind, the front, seas of 2-4 ft
are expected. Over the far outer edges of the central waters, a
brief period of seas of 4-5 ft will be possible through this
evening, especially with the Northwest wind fetch. No headlines
are planned through Sunday with high pressure in control.

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...Beach Hazards Statement from 8 AM EDT this morning through
     this evening for MEZ024>028.
NH...None.
MARINE...None.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
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ME...Beach Hazards Statement through this evening for MEZ024>028.
NH...None.
MARINE...None.
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&&

$$

NEAR TERM...Jamison
LONG TERM...Dumont