NWS Forecast Discussion

For Fremont, NH

FXUS61 KGYX 080317

Area Forecast Discussion
National Weather Service Gray ME
1017 PM EST Thu Dec 7 2023

If you thought last night was cold, well tonight will feature
temperatures as cold if not a couple degrees colder. However the
cold will be short lived, as a warming trend will begin Friday
and last through the weekend. Temperatures will climb into the
50s for many areas by Sunday, but rain will be close behind. A
strong storm will bring a combination of a soaking rain and
strong wind gusts to the area. It will be a quick moving storm
with clearing expected late Monday. Gusty winds continue and
colder temperatures return through midweek.


1017 PM Update... Deja vu all over again as stratus continues
to bank against the Whites in blocked NW flow late this evening.
Have taken the same logic as last night... with RAP low-level
moisture depicting these clouds well, and suggesting these
clouds hang around in convergent LL flow until the ridge moves
overhead by mid-Friday-morning. This brought lows up a bit for
the Connecticut River Valley vs the inherited, although the
remainder of the area is cooling quickly with flow going calm
under clear skies.

635 PM Update...Little to report at this hour. There is some
stratus working yet again into the upper Connecticut River
Valley this evening, so have incorporated this into the sky and
temperature forecast. Overall models aren`t as persistent with
overnight stratus toward the north as they were yesterday around
this same time in the evening... so overnight lows are intact,
with hourly trends incorporating more of last night`s hourly

High pressure remains firmly planted over the region which will
help to crash temperatures down once again under clear skies.
Up north low temperatures will fall below zero. The foothills
and interior will single digits and low teens. Across the south,
locations will see mid to upper teens. Clouds may spill over
into western New Hampshire tonight, but with a dry airmass
overhead there won`t be any worry for precipitation.


Short wave ridging tomorrow will make for another dry day with
light winds. High temperatures will be able to warm into the
upper 20s and low 30s in the north and mountains, and mid 30s to
near 40 across the south.

Ridging moves off to the east and a trough begins to approach
the region which will increase cloudiness from west to east as
the evening goes on. This will keep temperatures much warmer
than we have seen in recent nights. Expect temperatures in the
mid to upper teens to the north and 20s to the north. With a dry
airmass still overhead and no forcing, there shouldn`t be any
concern for precipitation during this period either.


Overview: Brief ridge slips east of the area Sat and will be
followed by a deep trof that gradually flattens but remains in
place thru the end of the week. Temps remain below normal...and
while precip may average above normal over the next week it is
mostly expected to fall Sun night into Mon.

Impacts: Storm system Sun into Mon will bring a combination of
strong winds and heavy rains. The extent of either remains
uncertain. At this time a period of strong wind gusts is likely
at the coast Mon morning...potentially greater than 60 mph north
of PWM. Poor drainage and overland flooding is possible across
all of the forecast area...with snow melt determining whether
river flooding occurs. See Hydrology section for more details.

Forecast Details: S/WV ridge axis moves east of the forecast
area Sat allowing deep southwesterly flow will set up over the
Eastern Seaboard. This will advect seasonally significant PWAT
values into northern New England. At this time the system
appears progressive enough to limit QPF to between generally
0.50 to 1.50 inches. I do not see the storm speeding up any from
current forecasts...so the trend to monitor will be if it slows
down at all or pivots and allows residence time of convective
fine line to linger over any areas. The Hydrology section below
covers the threats posed by rainfall in more detail.

The southerly LLJ will also increase with time into Mon morning
and bring a period of strong wind gusts to at least coastal
areas. The inland push of milder air and low level lapse rates
will be something higher resolution model guidance will start to
glimpse over the next 12 to 24 hrs...but at this time forecast
wind speeds at 925 mb suggest coastal areas are in line for at
least a wind advisory. The LLJ peaks mostly north of Casco
Bay...and so the Midcoast zones are more at risk of seeing gusts
come closer to high wind criteria. There is far more uncertainty
southwest along the coast...where LLJ orientation is more
southerly than southeasterly. This may limit the peak gusts and
inland extent of winds...especially across the Seacoast. Much of
this will also depend on storm track...where overnight guidance
was more easterly and kept strongest winds out to sea...07.12z
guidance came back west and maintained the wind threat. For now
I kept the forecast close to the median NBM
forecast...consistent other ensemble guidance on wind

Beyond the early week storm...CAA continues for much of the
week. This will keep winds gusty and colder than normal temps in
place. Precip chances will revolve around individual S/WV trofs
and upslope flow.


Short Term...VFR conditions will prevail through Friday.
Ceilings thicken as our next system approaches Friday night.

Long Term...VFR conditions expected for the majority of the
area to star the period Sat. Clouds will thicken and lower thru
Sun with widespread IFR or lower conditions in low CIGs and RA
thru Mon morning. A period of LLWS is also likely for coastal
terminals at least Mon morning. Winds shift to westerly Mon
afternoon and will remain gusty into midweek. Clearing is
expected quickly Mon south of the mtns...but MVFR CIGs may
linger around LEB and HIE in upslope flow.


Short Term...High pressure settling over the waters will keep
winds and waves below SCA thresholds. Freezing spray is possible
tonight through early tomorrow morning.

Long Term...Southerly winds will steadily increase ahead of the
next storm system. Storm force gusts will be possible for all
waters Sun night into Mon morning. I have used the highest of
wave guidance to get seas building to near 15 ft by Mon
morning...which may end up being higher if storm force winds are
realized. Winds shift to westerly behind the storm and will
remain gusts at least SCA thresholds thru the middle of the


A soaking rain is expected to move into the region Sunday and
increase in coverage and intensity Sunday night into Monday. The
moisture feed into the region pushes PWATs into the climatological
max territory (~1.2"), which is 3 standard deviations above normal.
Strong SW winds feeding the system will support high rainfall rates,
more comparable to the warm season. Heavy rain could result in urban
flood concerns and rapid rises on small streams, some of which have
recently grown ice. The big ? will be the snowmelt factor, which is
too uncertain to ascertain this far out. Coastal areas will
likely see a melt out, with notable loss in the coastal plains
to the foothills. System will need to be watched closely for
potential river flooding.






NWS GYX Office Area Forecast Discussion