Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Caribou ME
609 PM EDT Tuesday Oct 21 2014
low pressure will intensify south of the region tonight and move
slowly northward Wednesday into Friday. This system will bring
significant rainfall to the region.
Near term /through Wednesday/...
6 PM update...had to expand rain coverage into eastern downeast
locations and central Penobscot County. Also lowered temperatures a bit
downeast where rain has cooled the air.
Lots of rain on the way as low pressure Parks itself off the
southern New England coast. So far, has just been intermittent
light rain central/downeast. The first push of more substantial
rain comes tonight for downeast, and lingering into tomorrow. Not
looking for anything that heavy for tonight and tomorrow...just
intermittent light to moderate rain. The northern edge of the rain
for tonight and Wednesday will be a bit difficult to pinpoint, but
at this point, don't see the rain getting much further north than
Houlton until perhaps late Wednesday afternoon or Wednesday
evening. Becoming quite windy out of the northeast late Wednesday
near the coast.
Short term /Wednesday night through Friday/...
consensus model trends indicate whats left of the warm advcn rainfall
will be sliding east of the forecast area at the beginning of this period Wednesday evening.
This will leave most of Wednesday night with light or no rainfall over much of the
forecast area...xcpt the coast by Erly Thursday morning...where the beginning of a more
pronounced deformation rainfall band moving north-northeast from central new eng will
begin to affect this portion of the forecast area.
This deformation rainfall band will have the deepest moisture with the
greatest precipitable waters Thursday into Thursday night as it slowly slides nwrd into central
and eventually northern portions of the forecast area. Whats left of this band will exit
northern portions of the forecast area by midday Friday. We indicate the potential of heavy
rainfall in our grids Thursday through Thursday night approx in the area encapsulated
by the 0.50 inch 6 hrly quantitative precipitation forecast isopleths for each successive 6 hour period
during these two periods. Rn should taper to scattered showers S to north over the forecast area
Friday behind the departure of the deformation band. With cloud cover and
rainfall expeceted over the region through most of this period...diurnal/nocturnal
temperature differences will be sig less than climatology.
Long term /Friday night through Tuesday/...
cool and unsettled conditions will continue through the weekend with scattered
showers as whats left of the upper low from the Middle Atlantic States and
another upper trough from central can moves across the region. Drier
conditions and a warming trend will commence Erly next week as
upper level ridging replaces the upper trof/low.
Aviation /22z Tuesday through Sunday/...
near term: VFR for areas from Presque Isle north through
Wednesday, except perhaps going down to MVFR late tomorrow
afternoon as rain begins to move in. Houlton will be near the
north edge of the rain tonight into Wednesday, so tough call on
VFR vs MVFR there. Further south, expect Bangor and Bar Harbor to
go down to MVFR this evening as the rain moves in, then probably
fluctuating in between IFR and MVFR late tonight through Wednesday
with intermittent rain.
Short to long term: MVFR clgs expeceted across northern taf sites Wednesday night
into Thursday morning...with LIFR-IFR clgs and visibilities in rn downeast sites
during these periods. All sites should be LIFR to IFR in clgs and visibilities
with rn Thursday afternoon into Friday...with downeast sites improving to MVFR
by late Friday afternoon. Northern taf sites will remain IFR Friday night with
downeast sites MVFR then MVFR north and VFR downeast Sat and sun.
near term: northeasterly gales expected to develop late tonight
and persist into Wednesday. Seas will build from about 4 feet this
evening to 7 to 11 feet Wednesday. Could be some minor coastal
erosion issues with the high tide coming early Wednesday evening.
Don't think it's enough for a coastal Flood Advisory at this
Short to long term: the glw will continue through Thursday...with an interim
Small Craft Advisory likely needed for Thursday night. No hdlns needed for Friday into the
weekend at this time...with waves and winds possibly close to Small Craft Advisory thresholds
attms over the weekend. We kept close to ww3 WV guidance for this
ME...Flood Watch from Thursday morning through Friday morning for
Wind Advisory from 8 PM Wednesday to noon EDT Thursday for
Marine...Gale Warning from 5 am Wednesday to 8 PM EDT Thursday for