Area Forecast Discussion
Issued by NWS Portland, ME

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46
000
FXUS61 KGYX 282004
AFDGYX

Area Forecast Discussion
National Weather Service Gray ME
404 PM EDT Thu Mar 28 2024

.SYNOPSIS...
A stalled front brings another round of steady, heavy rains
tonight as low pressure tracks northward offshore. This along
with significant snowpack ripening or, in the case of the
coastal plain and adjacent interior, significant snowpack melt
will increase the threat for flooding. Precipitation ends as
snow Friday, especially across the higher terrain, before things
become drier and gusty over the weekend, especially Saturday.
Dry and warmer into Monday, with unsettled weather by the middle
of next week.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
Periods of rain continue to stream northward through the area
overnight tonight as stalled front remains offshore, with the
steadiest rain and highest amounts still expected along the
coastline. Patchy dense fog continues overnight, especially in
areas that still have snow cover present. A steadier round of
rain is moving in for the late afternoon hours, and then after a
brief showery period through the evening another steadier round
moves through the overnight hours as low pressure tracks
offshore. The last round overnight is mostly expected to miss
western New Hampshire, with the highest amounts toward the
MidCoast.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
The steadiest and heaviest rain continues through the MidCoast
and central Maine most of the day. The rain will try to end as a
bit of snow on the backside of the low by late in the day, with
the best chance for this across the higher terrain. Even so, a
brief burst of snow can`t be ruled out in the lower elevations
if the precip becomes heavy enough in the late afternoon as the
low goes by. New Hampshire spends most of the day dry, with a
fairly sharp cut set up through western Maine most of the day
tomorrow.

Winds become gusty by the late afternoon hours, especially
downwind of the mountains in Maine after the low passes by the
east. Gusty conditions continue overnight tomorrow night as
upslope snow showers continue through the higher terrain and
near the Canadian border. Relatively cooler air also begins to
return. Temps cool to near freezing along the coastline, with
mid 20s expected across northern areas as drier air moves in on
the northwesterly flow.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
Fairly amplified 500 MB pattern continues across NOAM and
environs which will be enhanced by fairly potent wave diving S
out of W Canada and closing off a 500 MB low over the E by the
middle of next week. This allows ridging to build late this
weekend into early next week, followed by troughing mid-late
week. Temps tend to stay fairly close to normal through the
period, trending a little of above normal this weekend and
slightly below normal next week.

Breezy conditions will continue into Saturday, in response to
deepening sfc low tracking NE through the maritimes. It should
be fairly sunny with highs around 40 in the mtns, to the mid to
upper to 40s along the ME coast, and into the low 50s in srn NH.
Winds diminish some some Sat night, but decoupling is unlikely
except in the most sheltered, but still enough CAA to push lows
from 20-25 in the mtns to the upper 20s to low 20s in the S.
There may be a surge of clouds late Sat night into early Sunday,
but it should clear out to at least partly, if not mostly sunny
by midday with highs a hair warmer than Saturday, and less
wind. Monday night will be mainly clear with lows mostly in the
20s. And Monday stays dry and warmer with partly sunny skies and
highs 45-50 in the mtns to 50-55 in the S.

It’s after this that the weather turns unsettled as the closed
low deepens to our SW, and generally pushes NE Wed-Thu. IT does
build a decent ridge ahead of it which may keep things
relatively dry on Tuesday, but Tue night through Thu look
relatively unsettle as that system pushes through with shower
and a period of steady precip at some point. Temps, both sfc and
aloft, look marginal for rain or snow, with the mtns showing the
best chc of a more significant snow, and climo says this will be
a mainly rain event for the southern zones, but given how far
out in the forecast it is, and we;re dealing with a closed low
separated from the flow, confidence is still low, despite some
agreement between the Euro and the GFS.


&&

.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
Short Term...Periods of IFR to LIFR continue at all terminals
into the overnight hours. Gradual improvement to MVFR and then
VFR progresses overnight and into tomorrow across western
terminals, with rain and IFR to LIFR continuing across coastal
terminals tomorrow. All terminals return to VFR tomorrow night,
but HIE likely sees periods of MVFR ceilings in upslope flow
tomorrow night. Northwesterly wind gusts to 30kts are likely
late tomorrow and tomorrow night.


Long Term...Mainly VFR Sat through Monday night, with potential
for some flight restrictions developing on Tuesday. NW winds
continue to gust to around 30 kt on Sat.

&&

.MARINE...
Short Term...Northwesterly gales develop across the outer
waters tomorrow afternoon as low pressure tracks through the
eastern Gulf of Maine and into Nova Scotia tomorrow night. These
continue into Saturday morning, with SCA conditions expected
across the Bays.


Long Term...SCA winds may persist into Sat night, but should
fall below criteria from Sunday through Tuesday.

&&

.HYDROLOGY...
Unfolding rain on snow event expected to continue for another
18-24 hours with minor flood conditions possible. The primary
impact will be small stream and river rises, and flooding along
low water crossing and urban areas due to rain and snowmelt.
Moderate rainfall will combine with warmer temperatures and high
dewpoints for snowmelt, with losses of 1 to 1.75" from the
existing snowpack, less in the headwaters. The latest forecast
track will keep the heaviest rainfall across central and eastern
Maine, with the regional flood risk highest along the Midcoast
and lower Kennebec River Valley with an additional 1-2" of rain
and 1" of snowmelt. Though there will be less rainfall, the
cumulative rain/snow runoff could be sufficient for small stream
and urban issues into southern NH and SW ME. A slight wobble in
the track or longer duration of rain could easily result in
more widespread impacts. Moderate river flooding is not expected
at the time of this issuance, with probabilities less than 10%.
Note: Many climate sites are in the top 5 wettest on record,
with this late month event expected to approach all time records
for Augusta and Portland. Portland`s record 11.24" in 2010,
Augusta`s is 9.71" in 1953.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...Flood Watch through Friday evening for MEZ009-012>014-019>022-
     024>028-033.
     Flood Watch through Friday afternoon for MEZ018-023.
NH...Flood Watch through Friday afternoon for NHZ004-006-008>015.
MARINE...Gale Warning from 2 PM Friday to 8 AM EDT Saturday for ANZ150-
     152-154.
     Small Craft Advisory from 8 AM Friday to 8 AM EDT Saturday for
     ANZ151-153.

&&

$$


NEAR TERM...Clair
SHORT TERM...Clair
LONG TERM...Cempa


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.