River Flood Warning 12, NWS Gray, ME

Area Forecast Discussion
National Weather Service Gray ME
1025 PM EDT Fri Nov 2 2018

.SYNOPSIS...
A front will remain stalled across New England into Saturday.
A series of low pressure disturbances will track along this
boundary bringing several rounds of heavy rain to the area
through Saturday morning. The last in the series of lows will
rapidly intensify as it departs into New brunswick late
Saturday. This low will generate strong and possibly damaging
winds late Saturday into Saturday evening. High pressure and
dry weather follows for Sunday. The next disturbance looks to
bring rain to the region by early next week.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
1020 PM...Overall, grids in decent shape, did some tweaking of
pops to better reflect arrival time of steady rain over the
next few hours. Added slight chc for TSRA overnight, given there
were a few flashed in NH last hour, and elevated cape will be
increasing a little bit later tonight.

735 PM...Have lowered pops thru the evening hours to show the
arrival of steady rain late this evening to around midnight.
MAde some minor adjustments to T/Td, but overall temps don;t
move too much tonight, and may rise slightly as we approach
daybreak.

Previously...At 18z a stationary front extended from the Gulf
of Maine through northern Massachusetts and extreme southwest
New Hampshire and into central New York state with a series of
weak waves rippling along it. NWS Doppler Radar mosaic showed
scattered convection across the area at moment with some
embedded thunder over New Hampshire. For tonight...we'll see
scattered convection through this evening along with areas of
drizzle and fog. The precipitation will once again expand in
coverage and become heavy at times overnight as a new low
develops over the mid Atlantic region and tracks into western
New England by morning. Strong upward vertical motion and the
rich moisture plume ahead of the sharpening upper trough should
produce some heavy downpours by late tonight.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
On Saturday the surface low tracks northeast and passes just
south and east of our higher terrain. We'll see rain heavy at
times in advance of the low with precipitation ending quickly
with passage of the surface low and the trailing cold front.
The upper trough goes negative tilt during this time and the
cold air injection into the system will cause the low to rapidly
deepen. While precipitation ends outside the mountains and we
see some clearing in the downslope flow...the mountains should
hold on to some rain...transitioning to accumulating snow as the
colder air floods in. The partial clearing and cold air advection
south of the mountains should allow us to mix quite readily and
it's likely in the high wind watch areas we'll see several hours
of strong wind gusts late tomorrow into tomorrow evening. Still
some uncertainty with respect to areal extent and strength of
the winds...so we'll leave the current watch in place before
deciding on advisory versus warning wind headlines. We'll see
another slug of one to two inches overnight into the day
Saturday mainly south of the mountains. That amount is
sufficient to push several rivers to near bankfull based
on latest ensemble and deterministic forecasts. One or two
river forecast points may briefly reach minor flood and there
could be some localized drainage and ponding of water late
tonight and into the day Saturday. Otherwise...no significant
hydro issues are expected at this point. For Saturday
night...winds gradually diminish with some lingering upslope
clouds and snow showers for the higher terrain and mostly clear
skies elsewhere.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
With the strong low pressure system transitioning into the short
term the extended has gotten a little less interesting.

Early on we will still have CAA and fair mixing...which should
lead to gusty NW flow early in the day Sun. High pressure
quickly moves into the region during the day however...and that
will allow winds to drop off in the mid afternoon. Probably the
most exciting news will be that we will see widespread sunshine
for a change! Surface ridge axis will be overhead Sun
night...and so I have gone with the colder guidance on min
temps. I expected that radiational cooling should be pretty
efficient...with the exception of valley fog. Given the extended
wet stretch it should be pretty easy for fog to develop...but
that may hold temps up a little.

As high pressure slides E and return flow sets up ahead of the
next S/WV trof a warm front will move Nwd towards the forecast
area. Given the Ely low level flow...that should set up cold air
damming and the development of low clouds N of the front.

A more significant trof will move thru the MS Valley and support
strong cyclogenesis thru the Great Lakes. This gale will
continue N into Canada...but will continue to drive a cold front
towards the Northeast. We lose the strongest forcing for
ascent...but an advancing line of showers and possibly thunder
will approach late Tue into early Wed. Deep cyclonic flow looks
to set up for the remainder of the week. We will likely see a
day or two of lingering low level moisture forced over the mtns
for upslope showers.

&&

.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
Short Term /through Saturday Night/...MVFR with areas of IFR
through Saturday midday in RA, fog, and widely sct TSRA. NW
surface winds developing Sat PM and gusting to 45 KT into Sat
evening before gradually diminishing. Across the mountains
MVFR and lcl IFR will linger in cigs and -shsn late Saturday...with
conditions improving to VFR elsewhere.

Long Term...With high pressure building in VFR conditions
prevail at all terminals Sun into Mon. After the wet conditions
of the past week...cool temps should allow for widespread valley
fog to form. LIFR conditions are most likely at HIE and LEB. A
warm front lifts into the area Mon night and Tue...and CIGs will
begin to lower with areas of IFR developing. Strong Sly winds
aloft should allow for a period of LLWS as well. The main cold
front and RA moves thru on Wed...and there is at least a chance
for some TSRA along it.

&&

.MARINE...
Short Term /through Saturday Night/...Winds and seas will build
rapidly Saturday as the surface low quickly intensifies during
the day. Have converted current watch headlines to warnings as
confidence is high we'll see strong winds across the waters
tomorrow into tomorrow night in developing strong cold air
advection behind the departing low.

Long Term...Will see some lingering gusts around 25 kts and seas
gradually diminishing early Sun in the wake of departing low
pressure. High pressure builds in quickly for Sun night into
Mon. Onshore flow begins to increase Tue and a period of SCA
conditions is likely.

&&

.HYDROLOGY...
Widespread 2 to 2.5" event will continue into Saturday. A
number of rivers across southern New Hampshire and into the
whites are expected to reach action stage with a chance for
minor flooding. Two key factors will determine the extent of any
flooding: the amount of rain received today, and the placement
of the axis of heaviest precipitation. The heaviest
precipitation has in general pushed south of the Whites into
southern New Hampshire. This should help to keep the flashier
rivers in the mountains out of flood stage but may make urban
flooding in the Manchester and Nashua area more problematic.

We'll see another slug of one to as much as two inches overnight
into the day Saturday mainly south of the mountains. That
amount is sufficient to push several rivers to near bankfull
based on latest ensemble and deterministic forecasts. One or two
river forecast points may briefly reach minor flood and there
could be some localized drainage and ponding of water late
tonight and into the day Saturday. Otherwise...no widespread
hydro issues are expected at this point and no headlines are
planned.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...High Wind Watch from Saturday afternoon through Saturday
     evening for MEZ018>028.
NH...High Wind Watch from Saturday afternoon through Saturday
     evening for NHZ007>015.
MARINE...Gale Warning from 2 PM Saturday to midnight EDT Saturday night
     for ANZ151-153.
     Storm Warning from 2 PM Saturday to midnight EDT Saturday
     night for ANZ150-152-154.

&&

SYNOPSIS...
NEAR TERM...Cempa/Schwibs
SHORT TERM...Schwibs
LONG TERM...Legro
AVIATION...
MARINE...
HYDROLOGY...

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>