Special Weather Statement, NWS Gray, ME

Area Forecast Discussion
National Weather Service Gray ME
1027 AM EDT Mon Jun 28 2021

.SYNOPSIS...
Hot will be the word today as temperatures rise into the 90s at
most locations. Heat index values may approach 100 degrees for
many lower elevation towns. A few showers and thunderstorms are
expected this afternoon and early evening which could bring gusty
winds and brief torrential downpours to a couple of towns. This
oppressive airmass may hang around the region into the middle of
the week with chances for showers and storms increasing each day
starting Wednesday. Further cooling is likely late in the week
with more showers possible.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
1015 AM Update...Very little change to today's forecast with
focus on heat inidices and scattered afternoon convection.
Observed temps heat up quickly with many areas in the mid to
upper 80s inland by late morning. Despite high instability/capes,
convection is expected to be limited with the capping
inversion. Some lift associated with an upper level jet entrance
region will be the focus for some storm initialization later
today. If anything, additional thunderstorms may develop along
outflow boundaries and a few storms may be capable of producing
gusty winds.

650 AM Update...Added a climate section below with the record highs
for today and tomorrow for PWM CON and AUG.

Previously...

Today should be the peak of the current hot stretch for most of
the forecast area with forecast highs in the 90s expected at
most locations with heat indices as high as 100F in the heat
advisory area. The heat advisory area remains unchanged as the
going forecast's temperatures and dewpoints look good.

Various CAMs continue to develop thunderstorms over northern and
central zones this afternoon, with a few stragglers as far south
as southwestern NH. Not much forcing for ascent expected today
with heights generally remaining neutral or even rising a bit.
However, some guidance indicates that the right entrance region
of an upper level jet will take a bit of a jog south today and
provide just enough lift to aid in thunderstorm initiation in
conjunction with a sagging SFC trough. Instability and wind
profiles indicate the potential for a few clusters or bowing
segments this afternoon, mainly along and north of a KHIE-KGYX
line. With SFC dewpoint depressions expected to be on the order
of 25 to 30F today, strong to potentially damaging winds will be
possible if not likely in the strongest cells this afternoon.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
Any showers and thunderstorms will quickly come to an end early
this evening. A dry but very warm night is expected once again
tonight, perhaps with a few area of fog, especially Midcoast ME.

Heights continue to gradually fall on Tuesday with best SFC
convergence across southern NH and south of there. This is where
the best chance will be for another round of thunderstorms
Tuesday afternoon. However, there is also a chance that any
storms remain south of the forecast area. We expect the rest of
the forecast area to remain dry. Temperatures will remain hot on
Tuesday, but a smidge cooler in the north. Dewpoint temps may
mix out a little better Tue afternoon and this may result in a
much smaller heat advisory area than today's.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
A blocky ridge-trough-ridge 500 mb pattern across North America will
become dislodged midweek as Pacific energy knocks the anomalous
ridge over the Pacific NW eastward. This will propagate a
trough from the Plains over the the Great Lakes with the ridge
responsible for our hot weather shifting south and east into the
Atlantic. The pattern does not look all that progressive with
the trough settling to our west and closing off into an upper
low over the weekend. Temperatures will trend much cooler after
Wednesday through the end of the week with a pattern conducive
for several bouts of rainfall. Details surrounding the timing
and placement of precipitation are thin at this time.

Wednesday looks to be the last day of significant heat in this
stretch of hot weather. A hot a humid airmass will still be in
place as northern New England is positioned between a trough
over the Great Lakes a ridge off the coast of southern New
England. South of the mountains and away from the Mid-Coast
temperatures will warm into the upper 80s to mid 90s and with
dewpoints in the mid 60s to near 70F heat indices will be a
couple degrees higher than ambient air temperatures. This will
likely bring heat advisory conditions to southern New Hampshire.

As the trough over the Great Lakes starts to dig Wednesday a
surface low will track through the St Lawrence valley dragging a
cold front near the International Border. Instability will be
more than sufficient for thunderstorms and bulk shear looks to
approach 40 kts across northern zones making organized
convection a possibility. The best chances for thunderstorms
will be across the north with decreasing chances towards the
coast as the front looks to wash out as it crosses the forecast
area.

Northern New England will be in a favorable region for ascent
Thursday as the trough axis remains to our west and jet streak
crosses the rooftop of Maine. There will be chances for showers
and thunderstorms across the area, although global models start
to diverge on placement (north versus south) as some models
start to form a cut off low over the Great lakes. Temperatures
will start their downward trend with highs 5 to 10F cooler than
Wednesday.

Uncertainty increases Friday into the weekend as global models
continue to diverge in handling the trough/upper low. Have
generally kept PoPs in the 30 to 50 percent range Friday through
Sunday as some solutions bring the upper low far enough west to
keep our area dry for some 12 to 24 hours periods. Temperatures
will continue their downward trend with highs in the 70s Friday
through Sunday.

&&

.AVIATION /14Z MONDAY THROUGH FRIDAY/...
Short Term...VFR conditions are expected today except in widely
scattered showers and thunderstorms this afternoon, mainly north
of KLEB-KPWM. A few of the strongest cells could produce brief
SFC wind gusts to around 45 knots this afternoon. Areas of fog
and stratus will be possible tonight, mainly Midcoast Maine,
possibly to KAUG and river valley locations farther west. VFR on
Tuesday.

Long Term...Chances for SHRA and TSRA will occur daily Wednesday
through the weekend bringing periods of restrictions with the
best chances in the mountains. Valley and coastal fog will also
have chances of occuring each night.

&&

.MARINE...
Short Term...Marginal SCA conditions this morning off the
Midcoast of ME will diminish early this morning. SCA winds could
come back up this afternoon and evening but for the time being
it looks like they will stay just under thresholds although we
will continue to monitor trends.

Long Term...Winds and seas will remain below SCA thresholds
Wednesday into the weekend.

&&

.CLIMATE...
Here are some high temperature records for today and tomorrow:

For Today:

Site        Record for Today (6/28)    Record for Tomorrow (6/29)

KCON        100 in 1901                97 in 1944
KPWM        98  in 1991                96 in 1944
KAUG        93  in 1991                90 in 1997

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...Heat Advisory until 8 PM EDT this evening for MEZ012>014-
     018>026-033.
NH...Heat Advisory until 8 PM EDT this evening for NHZ004>015.
MARINE...None.

&&

NEAR TERM...Ekster/Jamison
SHORT TERM...Ekster
LONG TERM...Schroeter

Hazardous Weather Outlook
National Weather Service Gray ME
338 AM EDT Mon Jun 28 2021

MEZ018-023-NHZ007>015-290745-
Interior York-Coastal York-Sullivan-Merrimack-Belknap-Strafford-
Cheshire-Eastern Hillsborough-Interior Rockingham-Coastal Rockingham-
Western And Central Hillsborough-
338 AM EDT Mon Jun 28 2021

...HEAT ADVISORY IN EFFECT FROM 11 AM THIS MORNING TO 8 PM EDT THIS
EVENING...

This Hazardous Weather Outlook is for southwest Maine, New
Hampshire, central New Hampshire and southern New Hampshire.

.DAY ONE...Today and tonight.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Heat Advisory.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

Heat and humidity peak Today, but remain in place into Tuesday and
Wednesday with heat indices in the middle to upper 90s expected.
Continue to monitor this period for updates as heat advisories will
likely be needed for one or both days.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

MEZ012>014-019>022-024>026-033-NHZ004>006-290745-
Southern Oxford-Southern Franklin-Southern Somerset-
Central Interior Cumberland-Androscoggin-Kennebec-Interior Waldo-
Coastal Cumberland-Sagadahoc-Lincoln-Interior Cumberland Highlands-
Northern Carroll-Southern Grafton-Southern Carroll-
338 AM EDT Mon Jun 28 2021

...HEAT ADVISORY IN EFFECT FROM 11 AM THIS MORNING TO 8 PM EDT THIS
EVENING...

This Hazardous Weather Outlook is for Maine, south central Maine,
southwest Maine, western Maine and northern New Hampshire.

.DAY ONE...Today and tonight.

Please listen to NOAA Weather Radio or go to weather.gov on the
Internet for more information about the following hazards.

   Heat Advisory.

There will be a chance for thunderstorms this afternoon. Some
thunderstorms will be capable of gusty winds and torrential
downpours.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

Heat and humidity peak Today, but remain in place into Tuesday and
Wednesday with heat indices in the middle to upper 90s expected.
Continue to monitor this period for updates as heat advisories will
likely be needed for one or both days.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

MEZ007>009-027-028-NHZ001>003-290745-
Northern Oxford-Northern Franklin-Central Somerset-Knox-
Coastal Waldo-Northern Coos-Southern Coos-Northern Grafton-
338 AM EDT Mon Jun 28 2021

This Hazardous Weather Outlook is for south central Maine, west
central Maine, western Maine and northern New Hampshire.

.DAY ONE...Today and tonight.

There will be a chance for thunderstorms this afternoon. Some
thunderstorms will be capable of gusty winds and torrential
downpours.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

Hazardous weather is not expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

ANZ150>154-290745-
Coastal Waters from Stonington, ME to Port Clyde, ME out 25 NM-
Penobscot Bay-
Coastal Waters from Port Clyde, ME to Cape Elizabeth, ME out 25 NM-
Casco Bay-
Coastal Waters from Cape Elizabeth, ME to Merrimack River, MA out
25 NM-
338 AM EDT Mon Jun 28 2021

This Hazardous Weather Outlook is for Atlantic coastal waters.

.DAY ONE...Today and tonight.

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday.

No hazardous weather is expected at this time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

Special Weather Statement
National Weather Service Gray ME
409 PM EDT Mon Jun 28 2021

NHZ002>004-006-282045-
Northern Grafton-Southern Carroll-Southern Coos-Northern Carroll-
409 PM EDT Mon Jun 28 2021

...A STRONG THUNDERSTORM WILL AFFECT EAST CENTRAL GRAFTON AND NORTH
CENTRAL CARROLL COUNTIES...

At 408 PM EDT, a strong thunderstorm was located near Lincoln, moving
east at 40 mph.

Winds in excess of 40 mph are possible with this storm.

Locations impacted include...
Lincoln, Franconia, Woodstock, Tamworth, Sandwich, Bartlett, Jackson,
Albany, Waterville Valley, Livermore, Hart's Location and Thornton.

This includes Interstate 93 between mile markers 95 and 108.

If outdoors, consider seeking shelter inside a building.

LAT...LON 4397 7176 4415 7171 4418 7119 4387 7123
TIME...MOT...LOC 2008Z 271DEG 34KT 4406 7161

Tubbs