Scientific Forecaster Discussion
fxus61 kcar 171441
Area forecast discussion
National Weather Service Caribou ME
941 am EST Wed Jan 17 2018
low pressure will approach from the southwest this morning and
track across the Gulf of Maine this afternoon. The low will exit
into the Canadian Maritimes tonight. High pressure will build
toward the region Thursday.
Near term /through tonight/...
930 am update: a little band of lgt sn formed ovr NE Aroostook
County this morn, but latest model trends indicate that this
will move east by aftn and the main synoptic snow band from
Millinocket swrd. Otherwise, minor chgs were made to hrly cld
cvr, temps, dwpts, and hi temps based on latest Sat and sfc obs.
Orgnl disc: overrunning light snow has broken out across
southern portions of the area as a coastal front sets up and
cyclogenesis occurs off the New Jersey coast. The low will
deepen some 10-14 mb over the next 18 hours as it tracks
northeastward towards Yarmouth Nova Scotia this evening. The low is well-
supported by a strong upper level jet streak and will be a
fast- moving progressive system. It'll speed away this evening
with a relatively weak northern stream upper trough
The Winter Weather Advisory will remain in place for today into
this evening. The storm track has shifted south along with the
entire snow forecast. The heaviest snow is now expected in
coastal Washington County. All precipitation is now expected to
remain as snow along the coast and outer islands with this more
southerly storm track. The heaviest quantitative precipitation forecast appears to be this
afternoon in coastal Washington County as the low tracks towards
the West Coast of Nova Scotia. During this time, snowfall rates
near the Washington County coast could reach an inch an hour.
Total snowfall amounts in coastal Washington County could reach
just over 7 inches, but since it's occurring in a period
exceeding 12 hours, will not upgrade to a warning. In the
coastal zones, had to bump up snow ratios above those suggested
by roebber or Cobb methods towards a 10-12 to one. Further
north towards Aroostook County, amounts were reduced with the
dry air in place such that areas north of Presque Isle will
receive less than an inch.
Snow will exit the region this evening and high pressure will
build. Blowing snow is not expected to be an issue with light
winds and clearing skies after midnight. Lows will drop towards
the single digits to low teens in most of the area except the
coast where upper teens to lower 20s are forecast.
Short term /Thursday through Friday night/...
high pressure will cross the region Thursday into Friday, with a
warm front approaching later Friday into Friday night.
Partly/mostly cloudy skies are expected across northern areas
Thursday into Friday, with mostly cloudy skies along with a
chance of light snow or snow showers Friday night. Across
downeast areas, expect mostly clear/partly cloudy skies
Thursday, with partly cloudy skies Friday. Temperatures will
be at slightly above normal levels Thursday/Friday.
Long term /Saturday through Tuesday/...
a warm front will cross the region early Saturday, with a cold
front crossing late. Expect mostly cloudy skies along with a
chance of light snow or snow showers across northern areas
Saturday. Across downeast areas, expect partly/mostly cloudy
skies early with partly cloudy skies late. Low pressure will
track toward the Great Lakes Sunday, with a developing warm
front to the east of the low. Partly/mostly cloudy skies are
expected across the forecast area Sunday. The low will lift
across the Great Lakes Monday while high pressure exits across
the Maritimes. Expect increasing precipitation chances Monday,
though how rapidly precipitation is able to advance with
retreating high pressure is still uncertain. Generally expect
precipitation in the form of snow Monday, though mixed
precipitation could develop downeast dependent on how rapidly
warmer air is drawn north. Uncertainty then develops Tuesday
regarding the track/timing of the Great Lakes low and whether a
secondary low develops across the region. Precipitation
types/amounts Tuesday will be dependent on the eventual track of
the low and whether a secondary low develops which could limit
the northern extent of warmer air. Generally expect above normal
level temperatures Saturday through Tuesday. However,
temperatures Monday into Tuesday will be dependent on the
eventual track/timing of low pressure and whether a secondary
Aviation /15z Wednesday through Sunday/...
near term: a wide variety of conditions will occur over the
area today. For starters, bhb and bgr will have steady snow all
day and into the early evening with IFR vis. IFR cigs may also
occur at bhb. Heavier snow will occur this afternoon towards
Machias and Eastport with 1/2 mile vis possible. Snow will move
northward and affect hul and pqi this afternoon into the evening
with IFR vis. Brief periods of snow and IFR vis may affect car
and fve this evening, but MVFR cigs appear to be the predominant
Short term: occasional MVFR conditions are expected across the
north and mountains Thursday into Sunday, with occasional IFR
conditions also possible Saturday. Generally VFR conditions are
expected downeast Thursday into Sunday.
near term: the Small Craft Advisory looks marginal by winter standards with some
25 kt gusts entering the waters this afternoon into the early
evening. Will maintain the headline as is. Otherwise, the most
significant weather will be steady snow closer to the coast with
reductions in visibility. Rain is expected to mix with the snow
Short term: Small Craft Advisory conditions are expected
Thursday into Thursday night. Conditions are expected to be
below Small Craft Advisory levels Friday into early Friday
night. Small Craft Advisory conditions will then develop again
later Friday night.
ME...Winter Weather Advisory until 11 PM EST this evening for
Marine...Small Craft Advisory until 7 PM EST this evening for anz050-