886
FXUS61 KGYX 061851
AFDGYX

Area Forecast Discussion
National Weather Service Gray ME
251 PM EDT Fri Jun 6 2025

.SYNOPSIS...
Showers and thunderstorms will be prevalent tonight as a
stationary front stalls over the area. This feature will linger
into Saturday, once again focusing shower development. Strong to
severe storms with localized flash flooding will be possible
through this evening. The next round of rain could pose
additional flood concerns for Saturday. A break arrives Sunday
as high pressure briefly builds. Conditions become unsettled
with the next week with widespread showers Tuesday into
Wednesday. Improving conditions expected for the second half of
the week.


&&

.NEAR TERM /THROUGH TONIGHT/...
Large scale ascent is just now arriving over the forecast area
and as a result convection is beginning to pop over parts of NH.
Coverage of showers and storms will continue to expand north and
east from this point.

Especially over the southern half of NH and adjacent
southwestern ME there is enough instability for stronger storms.
However we are lacking in shear...so organization is going to be
tough to come by this afternoon and evening. This should lend
itself towards pulse-type convection and/or merging cold pools
as storms cluster together later. There may initially be some
hail...but as time goes on wind will become the more dominant
hazard. Once we lose daytime heating the storms will also lose
their punch and start to scatter out.

There is more in the hydrology section below...but we also look
on track for heavy rainfall from any convection. HREF guidance
continues to show max QPF in the 3 to 4 inch range over 6 hours
this evening. This may also occur over a couple of
rounds...allowing the soil to saturate before the next round
arrives.

After the storm complex dissipates it will remain pretty moist
over the forecast area and fog may develop after midnight. It
will be highly dependent on how convection evolves over the next
few hours...so I have just patchy fog mention for now.

&&

.SHORT TERM /SATURDAY/...
The frontal boundary will linger into Saturday, with a wave of
low pressure riding along it. This will renew widespread
showers with some scattered convection. The environment will not
be supportive of severe storms due to limited shear and cape,
but there will be enough energy for periods of heavy rainfall.
This rain falling on already saturated grounds from Friday could
be sufficient to renew very localized flash flood concerns, and
potential for another flood watch. This will be dependent on
how this evening plays out and where the axis of heaviest rain
falls, before focusing on an area of flood risk tomorrow.
Expansive cloud cover and showers will keep temperatures capped
around 70. Some peaks of sunshine are possible in western
counties towards the end of the day as the front pushes east,
but most are the area will remain gloomy.

&&

.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
Ridging builds in Sunday providing a break in the weather with
sunny conditions and lower humidity. A negatively-tilted wave
swinging by Monday, increasing clouds and scattered showers with
cooler temperatures in the 60s. Conditions briefly dry out
Monday Night before a more amplified and organized upper trough
moves over the Great Lakes Tuesday. Increasing rain chances with
isolated thunder will develop as the system approaches, with
the cold front passing Tuesday night into Wednesday morning.
Looking at likely pops, and WPC Day 5 marginal ERO risk already
clips the Connecticut Valley. Afterwards high pressure build in
from the west and conditions dry out with seasonable
temperatures through the end of the week. At the time of this
issuance next Saturday`s forecast looks favorable with a low
probability for rain. Could it end the 12-13 straight rainy
Saturday run? Time will tell.

&&

.AVIATION /18Z FRIDAY THROUGH TUESDAY/...
Short Term...Scattered showers and thunderstorms will track
across southern NH into southern Maine through this morning that
will bring brief restrictions if the encounter any TAF site.
MOre widespread thunderstorms are likely this afternoon into
the evening with mainly VFR prevailing outside of any shower or
storm. Low cigs and fog will likely bring IFR/LIFR across much
of the area tonight. Some improvement is possible Saturday
morning while another round of showers and storms is likely late
Saturday morning into the evening.

Long Term...Conditions will gradually improve Saturday night
with VFR likely Sunday. Chances for showers increase Monday into
Tuesday that could bring periods of restrictions.

&&

.MARINE...
Short Term...VSBY restrictions possible in showers/thunderstorms
and even some fog over the waters through Saturday.

Long Term...Sub-SCA conditions. VSBY restrictions in showers
Tuesday/Wednesday.

&&

.Hydrology...
Significant flash flooding possible through this evening. A
flood watch is in effect for localized flash floods across
central and southern New Hampshire. A stationary front over the
area will keep a flood risk for parts of the area through
Saturday. As stated above, organized strong/severe convection
this evening will produce heavy rainfall. Storm motions will be
parallel with the flow, supporting backbuilding and training
potential, along with slow movers. These factors combined with
wet antecedent conditions could result in flash floods. Most
areas will be vulnerable to rapid runoff after 2-2.5", but some
areas could see 3-5" with repeated activity due to high rainfall
rates (~2"/hr). The quasi-stationary front will be the focus
for training, suggesting southern/central NH as the most
vulnerable. The front will remain a concern again on Saturday,
however the rainfall rates are expected to be less severe. The
flood risk tomorrow will also be highly dependent on the amount
and locations of heaviest rainfall today. It is likely that a
flood watch will be needed for parts of the area on Saturday,
unless the axis of heaviest rainfall falls outside of today`s
target areas.


&&



.GYX WATCHES/WARNINGS/ADVISORIES...
ME...None.
NH...Flood Watch until midnight EDT tonight for NHZ003>013-015.
MARINE...None.

&&
$$


NEAR TERM...Legro
LONG TERM...Jamison