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Area forecast discussion
National Weather Service Gray ME
1107 am EST Fri Feb 24 2017

Synopsis...
a weak cold front will stall just to our south early this
morning before returning north as a warm front by late today. A
strong cold front accompanied by widespread showers will cross
the region Saturday night followed by a drier and colder air
mass for Sunday into Monday. A disturbance will approach from
the west late Monday and Monday night.

&&

Near term /until 6 PM this evening/...
11am update: major update to temps for this afternoon thru Sat.
After a close look at temps it still appears guidance having a
major problem resolving strong waa pattern over the deep
snowpack. Have raised temps significantly over central and
northern areas this afternoon since temps already running about
10 degrees above forecast at 11am. Over southern areas raised
temps and dewpoints a few more degs. For tonight strong waa will
continue so not expecting temps to fall much so raised the
overnight min temps significantly. On Saturday the strong waa
pattern and southerly flow aloft continues so another warm day
and raised temps across all areas. No other changes attm.

945 am update: narrow band of showers across soutern New Hampshire and
extreme southern ME along a warm front moving north. This narrow
band of showers extends west thru upstate New York. Made adjustments
to pops based on latest radar and extrapolated timing forward
using hrrr. Also made significant adjustments to sky cover for
next several hours based on visible satellite imagery. Patchy
fog continues so will also move it forward to the noontime
hours. Temps seem on track with only minor tweaks needed based
on latest obs data. No other changes attm.

715 am...minor estf update to reflect the current mesonet as
well as radar trends in near term grids.

Prev disc...
at 07z...a cold front extended from our coastal waters into
southern New England then westward to a surface low over
Missouri. The surface front will stall just to our south by
morning. The surface low over Missouri will track into the
lower Great Lakes by evening, and begin to push our stalled
front northward as a warm front today. We'll see clouds lower
along and ahead of this boundary with showers breaking out
across the forecast area. There'll be some areas of drizzle and
fog as the warmer air spreads north over our diminishing
snowpack. There'll be a steep gradient in high temperatures
today, with readings only near 40 along the international
border while locations along the New Hampshire/Massachusetts
border warm to around 60 degrees.

&&

Short term /6 PM this evening through 6 PM Saturday/...
low clouds and fog with areas of drizzle is expected tonight as
the warmer air flows northward over the snowpack and Gulf of
Maine. The surface warm front should remain hung up just south
of the mountains and foothills where a few heavier showers will
remain possible. It'll be another unseasonably mild night with
lows ranging from the mid 30s to mid 40s.

On Saturday...a strong southerly flow should finally push the
warm front to our north. Temperatures will warm into the 50s and
lower 60s...with only the far northern mountains remaining in
the 40s. The fog should lift and we'll see mostly cloudy skies
with scattered showers becoming more widespread by late afternoon
ahead of an approaching strong cold front.

&&

Long term /Saturday night through Thursday/...
short wave trough embedded in broader and weak long wave
troughing will affect the region Sunday night. Near zonal
flow/weak ridging will be the rule thereafter until mid week.
Another disturbance arrives for the Wednesday-Thursday time
frame.

On Sunday a cold front will exit into the Atlantic Ocean with
upslope flow following in its wake. Ahead of the front
temperatures should warm into the mid 40s along southern and
coastal sections thanks to gusty westerly flow and compressional
warming. Showers should diminish by Monday early morning as
moisture diminishes. Temperatures will continue to be warm
Monday and Tuesday from the foothills south especially. Over the
north we will reach warmer readings by Wednesday as the next
warm front lifts over the region.

Widespread showers are likely beginning Tuesday and wrapping up
on Thursday. P-type will waver between snow and rain showers
with an area of rain/snow mix at the interface. This will be
largely dependent on surface temperatures and the time of
day...with snow move widespread at night and changing over to
rain during the daytime.

At week's end high pressure builds in ahead of the next low
pressure system churning/deepening in the Great Lakes region.

&&

Aviation /16z Friday through Tuesday/...
short term /through Saturday/...VFR with LCL IFR in fog through
13z...then conditions lowering to MVFR throughout with areas of
IFR in ceilings and -shra. Widespread IFR tonight in drizzle and
fog with LCL LIFR. Conditions gradually improving to MVFR with
areas of IFR Sat PM in ceilings and -shra.

Long term...precipitation will continue very lightly across the
mtns and possibly foothills into Sunday with areas of MVFR at
hie and leb. VFR Sunday night into Monday morning with -shra
developing across the mtns once again.

&&

Marine...
short term /through Saturday/...winds and seas remain below Small Craft Advisory
through tonight. Winds and seas should build to Small Craft Advisory on Saturday
ahead of an approaching strong cold front.

Long term...scas will continue/be needed as seas will stay in
the 5-7 ft zone until Monday night with gusts to 25-30 kts in a
similar time frame.

&&

Hydrology...
a Flood Watch remains posted for interior portions of Maine and
New Hampshire from 00z Saturday through 00z Monday. Daytime
temperatures will soar into the 50s and lower 60s through
Saturday with mild overnight lows. Light rain will move in today
as a warm front moves north producing around 0.25 inches across
mostly central and northern locations. On Saturday night, the
cold front moves through with another 0.50 to 0.75 possible. The
warmth will ripen and melt the snowpack with rivers and streams
responding both today and Saturday. Rainfall will add to the
runoff late from today through Saturday. At the current time,
the main threat is ice jam flooding. The threat is higher in New
Hampshire where temperatures will be warmest and precipitation
will be heaviest.

&&

Gyx watches/warnings/advisories...
ME...Flood Watch from 7 PM EST this evening through Sunday evening
for mez007>009-012>014-020-021.
New Hampshire...Flood Watch from 7 PM EST this evening through Sunday evening
for nhz001>009-011-012-015.
Marine...none.

&&

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