Area forecast discussion
National Weather Service Gray ME
1035 PM EDT Friday may 24 2013
Synopsis...
a cold front will push offshore and stall this evening. Low
pressure will develop on the front near Cape Cod and will slowly
drift north through the Gulf of Maine Saturday and Saturday night.
Low pressure will accelerate north into Labrador on Sunday. High
pressure will build in from the west Sunday night through Monday.
High pressure will shift offshore on Tuesday. A warm front will
approach from the southwest Tuesday night and Wednesday and will
push east of the region Wednesday night.
&&
Near term /through Saturday/...
update...
have updated grids based on current conditions...with the cold
front now having slipped south of the coast waters as of 0230z. Low
pressure will continue to take shape off the new eng coastline
thereafter...with cyclogenesis occurring near Cape Cod this
evening.
Latest hrrr model picking up well on convective segments crossing
the forecast area at this time. This model depicts more areas of
rain moving through the region late tonight and Saturday morning.
Will continue to monitor cold air rushing into the mountains from
Canada overnight. There could be some mixed snow and rain over the
higher terrain for this storm which is very similar to the may
26th 1967 event.
Have adjusted winds and temperatures for the higher terrain. Winds will
become rather gusty for any hikers out of the north and north over
the next couple of days...with some snow across the high terrain.
Previous disc...
cold front currently moving east through eastern New Hampshire
and northwest Maine and this boundary will continue to push off to
the east through the remainder of the afternoon. Front will stall
offshore this evening and will be the focus of light to moderate
rainfall in middle coast and central Maine during the remainder of
the afternoon into this evening. Will see a brief break in the
action across New Hampshire during the rest of the afternoon
before next batch of precipitation edges in from the west. Will take some
time for low pressure to get spun up overnight so this break may
translate eastward into western Maine for the evening hours before
850 over-running gets going in earnest across western Maine after
midnight.
12z models trending farther west with axis of heaviest precipitation and
coming into line with last night 00z European model (ecmwf). 24 hour quantitative precipitation forecast for the
mountains and Connecticut Valley Down to around an inch to 1.5
inches through 00z sun. With this in mind...doesn't appear
flooding will be an issue considering the break in the action
this afternoon and long duration of the event itself...so holding
off on any watches at this point in time.
&&
Short term /Saturday night/...
rain will continue Saturday through Saturday night as surface low
becomes trapped under upper level system and meanders around the
Gulf of Maine through Sunday morning. May see some wet snow over
the highest terrain at some point on Saturday in far western zones but
enough warm air wraps around the system that this would be fairly
brief. Better chance for this would be in The Greens of Vermont
and the dacks. Will be a cold and blustery day with temperatures holding
in the 40s in most areas and showing little change Saturday night.
&&
Long term /Sunday through Friday/...
upper level and surface lows lifting NE on Sunday with steadier prcp
becoming more scattered in nature and lighter in intensity. Any leftover
rain showers ending Sunday night as the system moves into the Maritimes.
Memorial Day looks like fair weather now with system pulling out far
enough to the NE. Still some cyclonic flow aloft and some leftover
moisture that could produce some cloudiness especially in the north/Montana
zones due to upsloping northwest surface winds. Might see an isolated rain showers in
the north/Montana zones otherwise no prcp expected on Memorial Day.
High pressure and upper level ridge build in for Tuesday into Wednesday.
The upper level ridge holds 0n over the eastern U.S. But a series of weak
upper level short wave troughs drive through the ridge for late Wednesday
and Thursday. This forms a warm frontal boundary to our S that
lifts north and will provide some cloudiness and isolated to scattered rain showers
from late Wednesday through Thursday. The upper level ridge becomes
better established over the East Coast Thursday night and Friday as the
short waves exit the coast. This should allow warm air to continue
moving in from the SW. Still can't rule out possible rain showers due to warm
fnt moving through.
Generally used blend of gfs40/NAM/met/mav/HPC quantitative precipitation forecast for periods 4
and 5 then gfs40, gmos, HPC qpf, mex MOS and wna4 for the rest of
the long term forecast.
&&
Aviation /03z Saturday through Wednesday/...
short term...IFR/LIFR ceilings tonight through Saturday night.
Long term /Sunday through Wednesday/...MVFR to possible IFR in rain showers
that will be tapering off Sunday into Sunday night. Mainly VFR
Monday through Tuesday and most of Wednesday.
&&
Marine...
short term...have extended Small Craft Advisory to go right through Saturday.
Although winds drop off at some point...waves will remain at least
in the 3 to 5 foot range...with greater seas out over the open waters.
Coastal Flood Advisory for minor splash-over around the time of
high tide.
Long term /Sunday through Wednesday/...Small Craft Advisory wind gusts and seas
possible Sunday through most of Sunday night then high pressure drops
conditions below Small Craft Advisory levels Monday through Wednesday.
&&
Fire weather...
no problems noted.
&&
Coastal splash-over...
very minor effects around the time of high tide which will occur shortly.
Gyx watches/warnings/advisories...
ME...coastal Flood Advisory until midnight EDT tonight for
mez023>028.
New Hampshire...coastal Flood Advisory until midnight EDT tonight for nhz014.
Marine...Small Craft Advisory until 6 PM EDT Saturday for anz150>154.
&&
$$
Jc
