A Brief Period Of Extreme Heat Incoming

Hazardous Weather Outlook

National Weather Service Caribou ME

934 PM EDT Sun Jun 22 2025

MEZ001>006-010-032-240145-

Northwest Aroostook-Northeast Aroostook-Northern Somerset-

Northern Piscataquis-Northern Penobscot-Southeast Aroostook-

Central Piscataquis-Northern Washington-

934 PM EDT Sun Jun 22 2025

This Hazardous Weather Outlook is for Central Highlands Maine, Far

Eastern Maine, Far Northern Maine and North Woods Maine.

.DAY ONE...Tonight.

Hazardous weather is not expected at this time.

.DAYS TWO THROUGH SEVEN...Monday through Saturday.

On Monday, high temperatures will climb into the middle 80s. By

Tuesday, high temperatures will climb to around 90. Muggy conditions

will make it feel warmer on Tuesday when heat indices may reach the

mid 90s to near 100 degrees.

Showers and thunderstorms from north of the area may approach

northern Maine Monday evening into Monday night. Some of the storms

could be strong if they reach the area.

A cold front will approach the area Tuesday afternoon. Isolated

strong to severe thunderstorms are possible ahead of the front.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather

conditions according to Standard Operating Procedures.

$$

368

FXUS61 KGYX 230001

AFDGYX

Area Forecast Discussion

National Weather Service Gray ME

801 PM EDT Sun Jun 22 2025

.SYNOPSIS...

Dangerous heat and humidity build early this week before

temperatures cool back down towards seasonable levels mid to

late week. Unsettled weather expected at the end of the week and

through the weekend.

&&

.NEAR TERM /UNTIL 7 AM MONDAY MORNING/...

8 PM Update...Quick update to expire the Beach Hazards Statement

and Heat Advisory that were in effect until 8 PM this evening.

Heat headlines for tomorrow through Tuesday remain unchanged.

Impacts and Key Messages:

* No significant impacts expected

Hot, breezy, and dry conditions will continue into the evening

before we get some relief overnight. The Heat Advisory today has

been maintained as current apparent temperatures within it are

around 96F. Some weak returns are showing up on radar in the

foothills, but mid level dry air is likely keeping anything from

reaching the surface. The exception has been Mt. Washington

where they have been occasionally reporting showers.

Temperatures and dewpoints will take a diurnal dip which will

help give us one more comfortable night before oppressive heat

arrives. Lows north of the mountains look to end up in the mid

to upper 50s, with areas to the south in the mid to upper 60s.

&&

.SHORT TERM /7 AM MONDAY MORNING THROUGH MONDAY NIGHT/...

Impacts and Key Messages:

* Dangerous heat begins to build in as areas of southern New

  Hampshire will see heat indices around 105F Monday, with of

  the rest of the state and parts of interior western Maine

  seeing heat indices of around 95F.

Surface high pressure moves overhead Monday with the 500mb high

continuing to build over the region. 850mb temperatures look to

warm upwards of +20C which, with the halfway decent mixing

forecast soundings depict, will continue to support surface

temperatures near or exceeding 90F for areas away from the

coast. The higher dewpoints near 70 degrees will be primarily in

southern New Hampshire which will push them toward apparent

temperatures exceeding the 105F threshold. There is some

suggestion in the guidance that maybe some slightly drier

dewpoints get mixed down with the continued northwesterly flow,

but with apparent temperatures exceeding 100F it is not worth

splitting hairs. For this reason went ahead and issued the

Extreme Heat Warning for southern New Hampshire where confidence

is highest that they will meet or exceed that threshold. The

rest of southern New Hampshire and even into southwestern Maine,

away from the coast, will still see some oppressive heat with

indices exceeding 95F, but an advisory will be sufficient there.

The New Hampshire and Maine coast will be spared by a seabreeze

that will keep apparent temperatures comfortable. The rest of

Maine will be spared by the comparatively cooler surface

temperatures, in the upper 80s, but heat indices will still be

around 90 degrees which is still potentially dangerous. I want

to stress that weather or not you are in a warning/advisory or

not, caution should be taken when outdoors during this period of

oppressive heat.

Temperatures won`t cool down much Monday night, before heating

up again the next day so the current warning area will run

through the night due to warm overnight temperatures being a

contributing factor to heat stress. Low temperatures will

generally be in the low 70s in the southern half of New

Hampshire, with upper 60s in the northern half and throughout

western Maine. This heat has potential to break daily records

for max daytime temperatures (see climate section below) and

possibly warm low temperatures.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...

Impacts:

*Dangerous and extreme heat expected Tuesday. Heat Index values

may exceed 105F across locations south of the mountains. Heat

index values may approach 100F north of the mountains.

*Thunderstorms are possible Tuesday evening, a few may become

strong.

*Unsettled and cooler weather towards the end of the week,

 continuing through the weekend.

Details...Tuesday:

There are many moving parts to the forecast that will lead to

extreme heat on Tuesday.

Typically, extreme heat days in New Hampshire and Maine require

clear skies, offshore/N/NW/Westerly flow, anomalously high

500mb heights and anomalously high temperatures at the top of

the mixed layer, and high mixed layers as well. There is high

confidence that most, if not all of the following will come

together on Tuesday.

Some light westerly winds over the mountains will allow for the

mixed layer to lift over western Maine. The higher mixed layer

should allow for temperatures across interior western Maine to warm

substantially through the day Tuesday. An area of high dewpoints

will shift eastward as well, allowing for a very unusually hot and

humid day across much of Maine. Locations south of the mountains

should see temperatures in the upper 90s. A possible exception here

would be places in the coastal Midcoast, such as Rockland and

Boothbay. Still these locations too look to be anomalously hot,

looking at mid-80s there. Opted to expand the active Extreme

Heat Watch to the coast, as guidance suggests heat index values

should meet criteria even in most of the coastal zones.

A few clouds associated with a cold front

to the north and light upslope flow should keep temperatures a hair

cooler north of the mountains, though relief will be minimal and

Heat Advisories will still likely need to be issued. Temperatures

north of the mountains look to be in the low 90s in the valleys and

80s at higher elevations.

A weak cold front moves through the area Tuesday afternoon. Timing

is uncertain, some model guidance has the front moving through

earlier in the afternoon. If this is the case, The front could help

cool off temperatures a little. However, the consensus appears

to favor a later passage of the front, allowing for the

aforementioned heat to build through the day. If storms develop,

there is potential that they could be strong, with heavy rain,

hail and winds being the primary threats Tuesday evening. The

SPC has issued a marginal risk over most of northern NH and NW

Maine.

Wednesday and onwards:

Afterwards, the ridge boosting out temperatures shifts west as

an upper-level low over the Canadian Maritimes moves southward.

This shift should allow for temperatures to sharply drop off

through the remainder of the week, with upper-80s likely on

Wednesday, and low 70s on tap for the end of the week. The

cooler temperatures will arrive with unsettled weather on

Friday, continuing through the weekend.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...

Short Term...VFR will prevail at most terminals through

tonight, with the exception being valley fog that may bring

about visibility restrictions at LEB and HIE. Gusty winds will

taper off around 23Z as well. Fog will burn off quickly Monday

morning and then VFR will then be the prevailing condition

through Monday night.

Long Term...VFR expected through the day Tuesday, some

restrictions possible as a cold front moves through towards the

end of the day. VFR expected through Thursday as mostly clear

skies continue. Lower restrictions are possible on Thursday and

Friday as unsettled weather may move through the area.

&&

.MARINE...

Short Term...High pressure building over the waters will keep

wind gusts and seas below SCA thresholds trough Monday night. A

sea breeze is expected to develop Monday afternoon.

Long Term...Southwesterly winds at 7-15kts expected Tuesday

morning. Winds become variable at 7-12kts through the rest of

the week. Seas will be 2-4ft on Tuesday, and through the

remainder of the week.

&&

.CLIMATE...

Anomalously high pressure will allow for dangerous heat and

humidity to build into the region. This heat could potentially

be record breaking for Monday (6/23) and Tuesday (6/24). Below

are the records for our climate sites

  Site             Record June 23rd    Record June 24th

Portland Jetport    91 (1983)              93 (1976)

Augusta             89 (1999)              93 (1963)

Concord             94 (2020)              95 (1980)

&&

.GYX WATCHES/WARNINGS/ADVISORIES...

ME...Heat Advisory from 11 AM to 8 PM EDT Monday for MEZ012-033.

     Extreme Heat Watch from Tuesday morning through Tuesday

     evening for MEZ012>014-018>028-033.

NH...Heat Advisory from 11 AM to 8 PM EDT Monday for NHZ002>006-009-

     010-013.

     Extreme Heat Watch from Tuesday morning through Tuesday

     evening for NHZ004>006-009-010-013-014.

     Extreme Heat Warning from 11 AM Monday to 8 PM EDT Tuesday for

     NHZ007-008-011-012-015.

MARINE...None.

&&

$$

NEAR TERM...Baron/Schroeter

SHORT TERM...Baron

LONG TERM...Palmer

URGENT - WEATHER MESSAGE

National Weather Service Gray ME

757 PM EDT Sun Jun 22 2025

MEZ012-033-NHZ004>006-009-231200-

/O.CON.KGYX.HT.Y.0003.250623T1500Z-250624T0000Z/

/O.CON.KGYX.XH.A.0001.250624T1500Z-250625T0000Z/

Southern Oxford-Interior Cumberland Highlands-Northern Carroll-

Southern Grafton-Southern Carroll-Belknap-

Including the cities of Milton, Ellsworth, North Conway, Albany,

Jackson, Ossipee, Harrison, Norway, Laconia, Bridgton, Rumford,

Brookfield, Bethel, Crawford Notch, Moultonborough, Wakefield,

Bridgewater, Holderness, Wolfeboro, Ashland, Oxford, Tuftonboro,

Plymouth, Lyme, Bryant Pond, Newry, Meredith, Hanover, Lebanon,

Naples, Gilford, Locke Mills, Chatham, Rumney, Conway, and

Fryeburg

757 PM EDT Sun Jun 22 2025

...HEAT ADVISORY REMAINS IN EFFECT FROM 11 AM TO 8 PM EDT MONDAY...

...EXTREME HEAT WATCH REMAINS IN EFFECT FROM TUESDAY MORNING THROUGH

TUESDAY EVENING...

* WHAT...For the Heat Advisory, heat index values up to 100

  expected. For the Extreme Heat Watch, dangerously hot conditions

  with heat index values up to 107 possible.

* WHERE...In Maine, Interior Cumberland Highlands and Southern

  Oxford Counties. In New Hampshire, Belknap, Northern Carroll,

  Southern Carroll, and Southern Grafton Counties.

* WHEN...For the Heat Advisory, from 11 AM to 8 PM EDT Monday. For

  the Extreme Heat Watch, from Tuesday morning through Tuesday

  evening.

* IMPACTS...Heat related illnesses increase significantly during

  extreme heat and high humidity events. Hot temperatures and high

  humidity may cause heat illnesses.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out of

the sun, and check up on relatives and neighbors.

Do not leave young children and pets in unattended vehicles. Car

interiors will reach lethal temperatures in a matter of minutes.

Monitor the latest forecasts and warnings for updates.

&&

$$

URGENT - WEATHER MESSAGE

National Weather Service Gray ME

757 PM EDT Sun Jun 22 2025

MEZ012-033-NHZ004>006-009-231200-

/O.CON.KGYX.HT.Y.0003.250623T1500Z-250624T0000Z/

/O.CON.KGYX.XH.A.0001.250624T1500Z-250625T0000Z/

Southern Oxford-Interior Cumberland Highlands-Northern Carroll-

Southern Grafton-Southern Carroll-Belknap-

Including the cities of Milton, Ellsworth, North Conway, Albany,

Jackson, Ossipee, Harrison, Norway, Laconia, Bridgton, Rumford,

Brookfield, Bethel, Crawford Notch, Moultonborough, Wakefield,

Bridgewater, Holderness, Wolfeboro, Ashland, Oxford, Tuftonboro,

Plymouth, Lyme, Bryant Pond, Newry, Meredith, Hanover, Lebanon,

Naples, Gilford, Locke Mills, Chatham, Rumney, Conway, and

Fryeburg

757 PM EDT Sun Jun 22 2025

...HEAT ADVISORY REMAINS IN EFFECT FROM 11 AM TO 8 PM EDT MONDAY...

...EXTREME HEAT WATCH REMAINS IN EFFECT FROM TUESDAY MORNING THROUGH

TUESDAY EVENING...

* WHAT...For the Heat Advisory, heat index values up to 100

  expected. For the Extreme Heat Watch, dangerously hot conditions

  with heat index values up to 107 possible.

* WHERE...In Maine, Interior Cumberland Highlands and Southern

  Oxford Counties. In New Hampshire, Belknap, Northern Carroll,

  Southern Carroll, and Southern Grafton Counties.

* WHEN...For the Heat Advisory, from 11 AM to 8 PM EDT Monday. For

  the Extreme Heat Watch, from Tuesday morning through Tuesday

  evening.

* IMPACTS...Heat related illnesses increase significantly during

  extreme heat and high humidity events. Hot temperatures and high

  humidity may cause heat illnesses.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out of

the sun, and check up on relatives and neighbors.

Do not leave young children and pets in unattended vehicles. Car

interiors will reach lethal temperatures in a matter of minutes.

Monitor the latest forecasts and warnings for updates.

&&

$$

URGENT - WEATHER MESSAGE

National Weather Service Caribou ME

137 PM EDT Sun Jun 22 2025

MEZ011-015>017-031-230915-

/O.CON.KCAR.XH.A.0001.250624T1500Z-250625T0000Z/

Central Penobscot-Southern Penobscot-Interior Hancock-Central

Washington-Southern Piscataquis-

Including the cities of Guilford, Lincoln, Amherst, Calais,

Springfield, Great Pond, Princeton, Dover-Foxcroft, Wesley, Milo,

Eastbrook, Aurora, Brewer, Howland, Old Town, Dedham, Grand Lake

Stream, Bangor, and Orono

137 PM EDT Sun Jun 22 2025

...EXTREME HEAT WATCH REMAINS IN EFFECT FROM TUESDAY MORNING THROUGH

TUESDAY EVENING...

* WHAT...Dangerously hot conditions with heat index values up to 106

  possible.

* WHERE...Southern Piscataquis, Central Washington, Interior

  Hancock, Central Penobscot, and Southern Penobscot Counties.

* WHEN...From Tuesday morning through Tuesday evening.

* IMPACTS...Heat related illnesses increase significantly during

  extreme heat and high humidity events.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Drink plenty of fluids, stay in an air-conditioned room, stay out of

the sun, and check up on relatives and neighbors.

Do not leave young children and pets in unattended vehicles. Car

interiors will reach lethal temperatures in a matter of minutes.

&&

$$

MStrauser