Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Caribou ME
657 am EDT Thursday Oct 23 2014
low pressure from the Middle Atlantic States will intensify as it
slowly moves northeast toward Nova Scotia today through Friday.
This system will bring rain...heavy at times across especially
central and downeast portions of the region. This low will move
into the open Atlantic on Saturday.
Near term /through tonight/...
630 am update...adjustments were needed to the probability of precipitation and quantitative precipitation forecast as
well based on the latest radar and observation. Heaviest rain moving into
central and downeast Maine under some strong deformation from
925-700mbs. Further north, a batch of lighter rain as moving west-northwest
across eastern Aroostook County. Kept rain chances for this area
through this morning and then a break before the steadier batch
arrives later this afternoon. The rain looks like it will dry up as
it moves toward the St. John valley through midday.
Temperatures were adjusted to match the latest conditions.
The latest model guidance including the NAM/GFS and Canadian Gem
have backed off on the heavy precipitation form their previous runs west/The
Crown of Maine staying pretty dry through much of today say north of
the Caribou-Presque Isle and Houlton areas. The dry air and upper
ridge winning out at this time. The NAM and Canadian Gem were doing quite
well per the 06z analysis. Therefore, decided to pull back on quantitative precipitation forecast
for this event into tonight given the latest reports coming in
west/less than an 0.75" of rainfall so far from this event west/the
exception of eastern Washington county(1.25"). This is far below
what the earlier guidance was advertising. We are still expecting
bands of heavy rainfall to moving into the region later today into
tonight as the low begins to lift to the NE. Given was has been
reported so far, decision was to lower the total quantitative precipitation forecast by at least
0.50 inches. This was collaborated W/gyx. There is a chance that
amounts might need to be lowered even more today if the later
guidance continues to pull back. Will keep the Flood Watch going
since it is up. Some minor flooding could occur but mainstem
rivers will hold below flood stage. The main issue will be
urban(clogged drains west/leaves) and lowland flooding. See hydrology
The other concern will be the NE winds. A Wind Advisory is in
effect through 12 PM today for the coast. Winds at this time are gusting
to 30 miles per hour with some sites over the Outer Island hitting 35+ miles per hour.
Another surge of stronger gusts is possible later this morning
especially west/the waves of heavier rain. So, gusts of 40-45 miles per hour are
possible but mainly over the outer islands.
Daytime temperatures are going to continue to be at or slightly
below normal. Overnight lows will range from upper 30s to lower
40s across the north and west while central and downeast are
expected to see middle to upper 40s.
Short term /Friday through Saturday/...
surface/upper level low pressure will track to the east of the Gulf
of Maine during Friday. Expect steady rain Friday morning to taper
to showers later Friday afternoon. Expect the heaviest rainfall on
Friday to be across northern areas with lessor amounts across
central and downeast areas. High temperatures on Friday will range
from the upper 40s to lower 50s.
Expect partial clearing Friday night as the low moves east of Nova
Scotia and is replaced by brief ridging both at the surface and
aloft. Lows Friday night will be in the low to middle 30s.
Saturday will be a mainly dry day between the low exiting through
the Maritimes and the next system that will be moving through
central Canada. Highs on Saturday will range from near 5s north
and low to middle 50s downeast.
Long term /Saturday night through Wednesday/...
low pressure will cross the region Saturday night through Sunday
with showers likely Saturday night and Sunday...especially across
northern areas. High pressure will begin to build across the
region from the west Monday night and then move east of Tuesday. A
warm front will lift northeast across the region Tuesday night
followed by a cold frontal passage Wednesday night. Colder weather
will follow for Thursday.
Aviation /12z Thursday through Monday/...
near term: VFR for the northern terminals west/the exception for
khul(mvfr) this morning. Kbgr and kbhb at IFR. The northern
terminals are forecast to drop to MVFR later this morning into
tonight. Khul is expected to drop to IFR west/tempo MVFR conditions
into tonight. Kbgr and kbhb are forecast to stay at IFR into tonight.
Short term: MVFR/IFR Friday in lingering rain then improving to
VFR Friday night and Saturday. MVFR in showers Saturday night and
Sunday. VFR Monday.
near term: gale force conditions will continue through the
afternoon west/another surge of gusts to 40 kts later this morning.
Buoys at this time are seeing gusts close to 40 kts. Conditions are
expected to drop to Small Craft Advisory levels this evening as the low level jet lifts
to the NE. Wave heights are 12-14 feet at this time and daycrew's assessment
right there. See no reason to change the wave height forecast
west/12-14 feet dropping to 7 to 10 feet tonight.
Short term: Small Craft Advisory conditions can be expected Friday
and into Friday night. Winds/seas are then expected to fall below
Small Craft Advisory levels for the weekend before increasing to
Small Craft Advisory levels by Monday.
as mentioned above, a Flood Watch remains in effect through
Friday. Rainfall totals are expected to be a bit less than
previously forecast. 2-4 inches looks to be a better fit. As
mentioned above, rainfall totals that have come over the last
24-30 hours have been under what the guidance was showing. Mainstem
rivers will show some rises, but will stay below flood stage west/the
expected rainfall. Small streams could reach bankfull. The biggest
problem will be poor drainage due to leaves clogging storm drains
and lowland flooding.
ME...Flood Watch through Friday morning for mez010-011-015>017-
Wind Advisory until noon EDT today for mez029-030.
Marine...Gale Warning until 8 PM EDT this evening for anz050>052.