me discuss
Office: GYX
FXUS61 KGYX 151039
AFDGYX
Area Forecast Discussion
National Weather Service Gray ME
639 AM EDT Tue Jul 15 2025
.SYNOPSIS...
Drier weather returns today with heat and humidity building in
through late week. Chances for afternoon showers and
thunderstorms return late week.
&&
.NEAR TERM /THROUGH TONIGHT/...
645 AM Update... Issued a dense fog advisory for portions of
western ME based on latest sfc observations. Otherwise, no
changes were made at this time.
Previously...
Key Messages:
-Increasing heat is expected today with afternoon heat indices
into the lower 90s in many interior locations with middle 90s
in extreme southern NH.
Discussion:
Nighttime microphysics satellite imagery early this Tuesday
morning shows a sharp clearing line quickly moving eastward in
the wake of the cold front. As the skies clear through dawn this
morning the lingering low-level moisture will likely result in
the formation of radiational fog in locations that are not
already currently foggy. The last of the rain is now over the
Gulf of ME and islands and therefore a dry remainder of the
overnight can be expected. Current temperatures are primarily
into the upper 60s/lower 70s and little in the way of additional
cooling is expected given the small dew point depressions.
Surface high pressure will build to our southwest today with
southwesterly flow prevailing across the region. This combined
with partly to mostly sunny skies will allow high temperatures
to warm into the upper 80s to near 90 degrees across most of the
region away from the immediate coast along with the mountains.
Dew points will begin the day into the lower 70s but some
increased afternoon mixing should lower them a bit into the
upper 60s. Therefore, heat indices will be within a few degrees
of actual air temperatures.
Latest guidance indicates that Canadian Wildfire smoke will
arrive from north to south today with ASOS/AWOS observations
over southern Quebec already reporting haze. The ME and NH DEP
is forecasting moderate particle pollution and based on this and
ground truth to the north I added haze to the grids.
&&
.SHORT TERM /WEDNESDAY/...
Mainly clear skies will prevail tonight along with light winds.
Some weak radiational cooling is possible but it will be another
warm night given that dew points will remain elevated, limiting
the cooling potential. Radiational fog may develop late along
with some marine fog along the coast. Overnight lows will fall
into the 60s across most locations.
Stout Bermuda High will continue to maintain a humid airmass along
the eastern Sea Board Wednesday. Dewpoints in the upper 60s to low
70s combined with highs in the low 90s will bring heat indices into
the mid 90s across interior western Maine and much of New Hampshire
south of the Whites. Embedded short waves within SW flow aloft will
bring slight chances for a shower or thunderstorm across western NH
Wednesday afternoon and evening.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
Long Term Update...Embedded short waves within a weak trough that
migrates east through the end of the week will bring chances for
showers and thunderstorms. The latest NBM brings the highest chances
for showers and storms Thursday while a lagging cold front will
continue chances through Friday. Global models and the 00Z NAM
suggest there will moderate instability Thursday with modest deep
layer shear and high PWATs so this will be the next day to watch for
any strong to severe storms and torrential rainfall. High pressure
will build in over the weekend bringing a cooler and drier air
mass.
Previously...
Pattern Overview: A shortwave trough crosses Thursday bringing
a chance for showers and thunderstorms, but the better day looks
like Friday as additional forcing comes in the form of a
surface front. Zonal flow through the weekend will keep
afternoon showers in the forecast with some suggestion that a
sharper trough may approach early next week.
Impacts and Key Messages:
* Heat and humidity peak midweek with heat indices reaching the
mid to upper 90s in southeastern New Hampshire and
southwestern Maine.
Details:
Thursday and Friday: Thursday sees increasing clouds and
shower/thunderstorm chances as a shortwave trough crosses the
area. CSU machine learning continues to show low probabilities
that a few storms could be on the stronger side. Long range
ensembles are showing another surge in moisture during this time
frame with the continued southwesterly flow driving PWATs up
across the area, so these probabilities are likely stemming from
precip loaded storms. With that being said any storms would be
capable of producing heavy rain which could lead to localized
flooding. Dewpoints peak in the low to mid 70s on Thursday, but
surface temperatures will be a degree or two cooler than the day
before. Despite the cooler temperatures, higher dewpoints
likely will necessitate Heat Advisories for Thursday as well.
Thursday remains a warm night with temperatures similar to
Wednesday night. Friday looks very similar with the addition of
a surface front that would provide further forcing potentially
leading to more widespread showers/storms. Trends will have to
be watched during this time period as timing of fronts is always
tricky, but nonetheless CSU continues to show low probabilities
of stronger storms and WPC has targeted these days with
Marginal Risks for the heavy rain potential. Depending on the
timing of the front there is likely going to be an interesting
temperature gradient with locations behind the front dropping
into the 70s with lower humidity and locations ahead of the
front during peak heating in the mid to upper 80s with humidity
holding strong. If the front does clear the area by nightfall,
it would make for a cooler night as well.
Saturday-Monday: A drier airmass is ushered in behind the front
for the weekend with temperatures feeling much more pleasant.
Zonal flow aloft, with some suggestion of brief shortwaves
rotating through, keeps low chances of pop-up afternoon showers
and storms in the forecast. Global models than suggest a sharper
trough and surface low pressure develop early next week which
may be the next best chance for widespread showers and storms,
but this is still out in time and unsurprisingly models greatly
vary in representation of this feature, so its only worth a
mention for now.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
Short Term...Low ceilings combined with FG will continue to
result in locally IFR-LIFR restrictions through an hour or so
either side of 12Z this morning. Mainly VFR conditions are then
expected later today with SW winds of 5-15 kts. Ground FG may
develop again tonight, especially across coastal and valley TAF
sites. Otherwise, VFR conditions and light S-SW winds will
persist on Wednesday. No LLWS is anticipated.
Long Term...Low stratus and fog will be present Wednesday night
and Thursday morning bringing about IFR/LIFR restrictions.
Ceilings during the day Wednesday should be VFR with more in the
way of MVFR ceilings looking likely with widespread shower
activity and a few afternoon thunderstorms Thursday and Friday.
&&
.MARINE...
Short Term...Winds and seas to remain below SCA thresholds
through the period. Marine fog will persist through this morning
before dissipating some later today and then returning again
tonight.
Long Term...Wind gusts and seas remain below SCA criteria
through Friday. Increasing southwesterly flow will continue
areas of fog development through at least Friday morning.
Afternoon showers and thunderstorms may also move over the
waters on Thursday and Friday.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...Dense Fog Advisory until 9 AM EDT this morning for MEZ012>014-
019>022-025>028-033.
NH...Heat Advisory from 11 AM this morning to 8 PM EDT this evening
for NHZ012-013.
MARINE...None.
&&
$$
NEAR TERM...Tubbs
SHORT TERM...Schroeter/Tubbs
LONG TERM...Baron/Schroeter
Office: CAR
FXUS61 KCAR 150832
AFDCAR
Area Forecast Discussion
National Weather Service Caribou ME
432 AM EDT Tue Jul 15 2025
.SYNOPSIS...
High pressure will build across the region today into Wednesday.
Low pressure will cross the region Thursday, followed by
another cold front on Friday. High pressure returns on Saturday.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
4:30 AM Update...Decided to issue a Dense Fog Advisory for the
Bangor region and Downeast through mid-morning. Observations
show visibility in Bar Harbor at one-quarter mile. Webcams from
other Downeast airports also show areas of dense fog at this
time. This fog will burn off later this morning.
Previous Discussion...
High pressure will be in control of the weather across Northern
and Eastern Maine in the Near-Term period. This will result in
mostly sunny skies during the day and mostly clear skies
tonight. 850mb temperatures of 16-17C today support highs well
into the 80s for inland locations. Some of the warmest spots
along and southeast of Interstate 95 could reach 90 degrees.
With dew point temperatures in the lower to mid 60s, heat index
values should stay just below heat advisory criteria everywhere.
Southwest winds will cool off the immediate coast, resulting in
highs in the 70s there.
Weak upper-level energy will pass through central and northern
areas this afternoon. This could touch off an isolated shower or
two from the Central Highlands northward. Most places will stay
dry, but still believe the CAM guidance is handling the
situation better than the NBM. A rumble or two of thunder will
be possible over the Crown of Maine. The threat of any showers
or thunderstorms will quickly end this evening with the loss of
daytime heating. Enough radiational cooling is expected north of
Katahdin to allow lows to drop into the upper 50s to lower 60s.
Generally mid 60s for lows tonight elsewhere, except at the
coast where lows will be in the 50s to lower 60s.
Hotter and more humid conditions for Wednesday, as 850mb
temperatures rise to 18-19C. Many inland lower elevation
locations will reach or exceed 90 degrees. Dew points will rise
to near 70 degrees from around Dover-Foxcroft and Lincoln
southward. Heat advisories may be needed for these area
southward to Bangor for Wednesday afternoon. However, not enough
confidence to issue at this time due to borderline values.
Further north, dew points will be in the mid 60s, which will
limit heat index temperatures there. Southerly winds will keep
Coastal Downeast cooler. Expect 60s and 70s at the immediate
coast and outer islands, with lower 80s closer to Route 1. An
approaching cold front could bring isolated showers or
thunderstorms in the afternoon over the Crown of Maine. However,
the warm air aloft will likely limit the threat.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/...
Warm temperatures will continue into the night Wednesday night,
with low temperatures only falling to into the mid to upper 60s
across much of the forecast area. These warm temperatures, along
with elevated dewpoints in the 60s, will not offer much relief
from the heat of the previous day.
On Thursday, a shortwave supported by the right entrance region
of a jet streak positioned north of the St. Lawrence River, will
bring the next round of showers and storms to the forecast area.
The heat that will have settled over the region will aid in
providing instability, with plenty of southerly moisture
advection persisting into the area. PWATs will be abnormally
high, lifting into the 1.3 inch range by 12z Thursday which is
around the 90th percentile for the area, and then rising
further towards 2 inches by 00z Friday, which well exceeds the
90th percentile for northern Maine. Any stronger showers or
storms could easily tap into this high moisture content,
resulting in the threat for moderate to heavy rainfall, and the
chance for localized flooding, particularly in any poor drainage
areas.
The greatest threat for thunderstorms on Thursday will be across
the northern half of the forecast area, closer to the synoptic
forcing from the jet streak dynamics to the north as well as an
approaching cold front, still off to the west at this time.
Additionally, a sea breeze is likely given the southerly flow
ahead of this shortwave, which will bring more stable conditions
into the Interior Downeast region.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
A cold front from the west will enter the forecast area early
Friday morning and quickly swing through the area through the
day. With frontal passage expected through the north by mid
morning on Friday, the chance for any stronger storms in the
north is low. However, the front will continue to push into the
Downeast region through Friday afternoon, which will line up
better with peak diurnal heating and could result in a few
thunderstorms through the afternoon and evening. Elevated
moisture levels remain ahead of the front, and so there could
still be areas of moderate to heavy rainfall with the frontal
passage into Friday afternoon. However, a drier air mass is
moving in behind the front, and will quickly end the threat of
heavier rain after the boundary moves through.
High pressure should return through the day on Saturday, with
drier weather and more seasonable temperatures as highs lift to
around 80 throughout the forecast area. The next system will
approach from the west on Sunday, though the recent model trends
from the 00z GFS and CMC both have shifted towards a slow moving
front from the north draping into the area instead of a low
pressure tracking across the center of the state. Uncertainty
still remains at this time on how this next low pressure system
will evolve, and how widespread or isolated rain chances may be
heading into early next week.
&&
.AVIATION /09Z TUESDAY THROUGH SATURDAY/...
NEAR TERM:
KFVE/KCAR...Brief IFR/LIFR possible through 11-12z with low
cigs. Otherwise, mainly VFR through today, tonight, and
Wednesday. PROB30 of TSRA around 18-22z. Isolated TS possible
again Wednesday PM. W winds 5-10 kts today. Light and variable
winds tonight. SW winds 5-15 kts Wednesday.
KPQI...IFR/LIFR through 10-12z with occasional fog. Then mainly
VFR through today, tonight, and Wednesday. VCSH possible this
PM and Wednesday PM. Isolated TS possible as well, but not
enough confidence to include in 06z TAFs. W winds 5-10 kts
today. Light and variable winds tonight. SW winds 5-15 kts
Wednesday.
KHUL...Brief IFR through 10-12z with low cigs. Otherwise,
mainly VFR today, tonight, and Wednesday. W winds 5-10 kts
today. Light and variable winds tonight. SW winds 5-15 kts
Wednesday.
KBGR/KBHB...Mainly LIFR through 12z with low cigs and FG.
Improving to VFR by around 14z. IFR/LIFR possible again tonight
with low cigs and BCFG, mainly at KBHB. W winds 5-10 kts today.
Light and variable winds tonight. SW winds 5-15 kts Wednesday.
SHORT TERM:
Wed night: Generally VFR across the north, trending towards MVFR
late. MVFR/IFR at Downeast terminals, potentially LIFR, in FG
overnight. Winds light and variable.
Thurs: All sites trending towards low end VFR to MVFR as rain
moves in from the north. Thunderstorms possible, mainly at
northern terminals. S winds 5 to 10 kts.
Thurs night: MVFR/IFR over most terminals, with FG possible
along with lingering rain showers. Light S winds may begin to
shift NW late at FVE/far northern terminals behind frontal
passage. LLWS possible ahead of the front.
Fri: MVFR/IFR early, quickly lifting to VFR behind frontal
passage from north to south. Winds shifting NW 5 to 10 kts with
gusts to 20 kts. LLWS possible ahead of the front.
Fri night - Sat: VFR across all terminals with SKC. Winds light
and variable.
&&
.MARINE...
NEAR TERM: Winds and seas will remain well below Small Craft
Advisory criteria today through Wednesday. Wave heights will be
around 1-2 feet, with southwest to south winds 5-10 kts. Fog
will reduce visibility on the waters, especially during the
nighttime hours.
SHORT TERM: Winds and seas will likely remain below small craft
advisory criteria through the end of the week and into this
weekend. Fog may reduce visibility over the waters Wednesday
night through Thursday night.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...Dense Fog Advisory until 9 AM EDT this morning for MEZ015>017-
029-030.
MARINE...None.
&&
$$
Near Term...Clark
Short Term...AStrauser
Long Term...AStrauser
Aviation...Clark/AStrauser
Marine...Clark/AStrauser
