Stratham, New Hampshire 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

071
FXUS61 KGYX 031501 AAA
AFDGYX

Area Forecast Discussion...UPDATED
National Weather Service Gray ME
1001 AM EST Tue Dec 3 2024

.SYNOPSIS...
A broad and chilly cyclonic flow will remain over the region
today, bringing a few flurries or snow showers to the
mountains. A complex series of upper level troughs will once
again cross the forecast area Wed night and Thu with snowfall
and some rain. Afterward, gusty winds and a very cold airmass
moves in behind the late week system bringing below normal
temperatures.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Update...Minor changes to reflect latest observational trends.
Mostly expanded the coverage of snow showers and flurries again.

Previously...

Very similar day expected today as compared to yesterday with
stratocu in the mountains with occasional upslope snow showers.
Downstream over the lower elevations, partly sunny skies will
likely give way to variable cloudiness this afternoon as weak
instability allows for strato-cu to spread southeastward. Highs
will be similar to the values seen on Monday, with readings in
the 20s in the mountain zones and 30s at lower elevations.
Westerly winds will be rather light at 5 to 10 MPH.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
Another chilly night tonight with widespread lows in the teens.
Clouds will gradually diminish downwind of the mountains this
evening but remain in the mountains where flurries and snow
showers may very well persist, especially the first half of the
night.

Widespread WAA occurs on Wednesday as a short wave trough and
attendant low pressure system approaches from the west. The
result will be slightly warmer highs with increasing high
clouds during the day, particularly during the afternoon hours.

The forcing for ascent may be sufficient for light snow or
flurries to begin across westernmost zones (CT River Valley) by
the end of the today period (6-8 pm).

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
Long Term Update... The main focus during the long term period
continues to be on the clipper system for Wednesday night and
Thursday. Overall the model trends have remained quite
consistent over the last few runs with this system, and that has
remained the case tonight.

One aspect of the system that is starting to appear as the
system comes into view on the mesoscale guidance is the
balancing act between the cold and the moisture with a
strengthening coastal wave. The 3km NAM showcased this, with a
more robust low bringing more moisture into interior areas, but
also pulling in a wedge of warm air into central and even parts
of northern Maine. The stronger the low the more moisture will
be in play for higher snowfall amounts, but also a further
northward pushing rain/snow line. So this is one features that
bares watching as the system comes into better view on the
mesoscale guidance today, with the heaviest band of snow likely
to be just west of the rain/snow line across parts of central
and northern Maine.

Full Discussion...

Pattern Overview: Upper level ridging overhead Wedensday will
briefly bring a break from any precipitation. An upper low
approaches and passes north of our area Thursday. This will
provide the forcing for precipitation Wedensday night through a
good part of Thursday. Afterward, broad troughing will be just
enough to keep precipitation chances through much of the
weekend, but the bigger story will be below normal temperatures.


Impacts and Key Messages:
* Slick travel possible during the Thursday morning commute
* Gusty winds Friday may pose a limited risk for power outages
* Subzero wind chills possible across much of the area early
  Saturday morning

Details: Upper level ridging will keep the area dry during the
day Wednesday, but as upper level moisture increases ahead of
approaching vertically stacked low pressure skies will cloud up
as the day goes on. High temperatures look to end up in the 20s
north and 30s south. Snow begins to break out around the 7 PM
hour in northern zones, overspreading the area overnight. Models
have come into better agreement on a track that takes the
center just north of our area, meaning snow amounts look higher
in the mountains and foothills (around 2-4 inches), but decrease
quickly heading toward the coast where temperatures are going
to end up more marginal. These areas look to end up around just
an inch or 2 at best. Obviously there is still plenty of time
for slight shifts in the track that would pull amounts either
way, so we will be watching closely. This system has just
started to come into view of the hi-res models so it would be
tough to pinpoint any areas of concern at this point, but
broadly speaking locally higher amounts are possible in northern
Coos county and the Western Maine Mountains as the 700 mb low
looks to track just north of this area. Models are also honing
in on enough of a temperature gradient developing overnight
along the coast that frontogenesis could intensify snow rates
somewhere in the coastal plain. So, even though they might only
receive an inch or two before a switch to rain, they may receive
it in a short period of time. With all that being said the only
impacts on the mind at this point would be slippery travel
during the morning commute away from the immediate coast.

Precipitation quickly tapers off Thursday, and then attention
turns to a tightening pressure gradient as the system departs to
the north. Confidence is increasing on wind gusts in the
ballpark of 30-35 mph across much of the area Friday, with Euro
ensemble probabilities up to a 60-70% chance of approaching 40
mph in northern zones and along the coast. Leaves aren`t on the
trees this time of year, but would think this could still lead
to a limited risk for power outages, especially in those areas
where they are still holding on to heavy wet snow. A much colder
airmass moves in Friday as well leading to low temperatures in
the low teens and single digits, and while gusts will be
subsiding overnight it is likely much of the area experiences a
period of subzero wind chills by early Saturday morning.

These cold nights continue though the weekend as well as some
low chances for precipitation as the region ends up under a
broad troughing pattern. Models have some differences in timing
and weather features heading into early next week, but all have
flow turning more southwesterly which would begin to nudge temps
back toward normal.

&&

.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
Short Term...Widespread VFR conditions expected thru Wed.
Upslope SHSN continue thru the day Tue...so some local MVFR CIGs
are possible at HIE.

Long Term...Ceilings will begin to lower toward MVFR during the
day Wednesday, with snow breaking out Wednesday night. This likely
brings periods of at least IFR restrictions to all terminals
overnight. Heading toward Thursday morning, visibility
improvements may occur at coastal terminals as a transition to
rain begins. Otherwise, conditions trend back to VFR overnight
Thursday. VFR prevails through Saturday with a chance for
ceilings and visibility to trend down again Saturday night.

&&

.MARINE...
Short Term...Winds and seas expected to remain below SCA
thresholds thru tonight.

Long Term...Winds and seas build above SCA conditions Wednesday
night as strong low pressure moves into the region. By Thursday
night wind gusts may be approaching gale force, lasting until
Friday night. Afterward, winds and seas begin to subside,
potentially falling back below SCA criteria on Saturday.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...None.
NH...None.
MARINE...Small Craft Advisory from 6 PM Wednesday to 4 PM EST Thursday
     for ANZ150-152-154.
     Small Craft Advisory from 6 PM Wednesday to 10 AM EST Thursday
     for ANZ151-153.

&&

$$

NEAR TERM...Legro
SHORT TERM...Ekster
LONG TERM...Baron/Clair/Ekster