Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Caribou ME
724 PM EST Friday Nov 28 2014
high pressure will build across the region overnight through
Saturday. A warm front will cross the region Sunday. A cold front
will then cross the region Monday.
Near term /through Saturday/...
an upper level disturbance will cross the region early tonight
with mostly cloudy skies along with isolated snow showers or
flurries with little or no snow accumulation. Surface high
pressure will then begin to build east across the region overnight
with partly cloudy/mostly clear skies. Overnight low temperatures
will be dependent on the extent of cloud cover and how rapidly the
cloud cover decreases. Generally expect low temperatures to range
through the single digits to around 10 above across northern and
central portions of the forecast area...with around 10 interior
downeast and through the teens to around 20 along the downeast
coast. Have updated the forecast to adjust for current conditions
along with overnight temperatures and cloud cover.
high pressure will crest over the state Saturday morning then
begin moving to the east later in the day. Have used a model
consensus approach for probability of precipitation...quantitative precipitation forecast and sky conditions and blended
the NAM...GFS and European model (ecmwf). For temperature and dewpoint have
initialized the grids with the superblend and then lowered
temperature a few degrees due to seasonably cold air mass in
Short term /Saturday night through Monday/...
at the start of the period...a high pressure ridge will be moving
east of the area as a warm front approaches from the SW. The
primary low with this warm front will be centered over Northern Lake
Superior. By early Sun morning the warm front pushes into western
Maine...with the GFS a bit faster than the European model (ecmwf). By Sun morning the
GFS moves the warm front to eastern ME/western New Brunswick. The European model (ecmwf)
has the warm front into central Maine. By middle day the GFS moves
the warm front into New Brunswick...moving Maine into the warm
sector...with the cold front to the northwest of Maine over Quebec city.
The European model (ecmwf) moves the warm front into western New Brunswick...with the
approaching cold front west of Quebec city. Both models move the
cold front into northwest ME Monday morning. The GFS moves it into the southern Gulf
of ME by the end of the period...the European model (ecmwf) extends it along the
coast of Maine by the end of the period.
Loaded a blend of the GFS/ECMWF/Gem/NAM through the short term
period of the forecast for hrly temp/dp...wnd/pop/sky. Loaded
nawave4 for seas in the coastal waters. Added 15 percent to winds
for gusts over land 30 percent over the coastal waters. Used
hpcgrids for quantitative precipitation forecast...ECMWF/GFS blend for the last 12hrs.
Long term /Monday night through Friday/...
at the start of the extended the GFS and European model (ecmwf) are in good
general agreement over system...however the European model (ecmwf) in about 6 hour
behind in the timing of the system movement. Monday evening the GFS
shows a cold front over the southern Gulf of Maine waters...with high
pressure ridging into southern Maine...a trough extending west across
northern Maine...an upper level trough extending south out of northern
Canada across Quebec to just south of James Bay. The European model (ecmwf) shows
the front extending SW along the Maine coast...and moves it off
shore early Tuesday morning. Both models show our weather dominated by
high pressure for through early morning Wednesday. Wednesday morning both models
show the next frontal system moving into western ME. Both with a cold
front moving into western Maine front a system over Hudson Bay...the
European model (ecmwf) showing a more dynamic system extending much farther south
than the GFS. From here the models solutions differ. The GFS
stalls the front over Maine...with it becoming stationary over the
southern half of the state through Friday evening. The European model (ecmwf) shows a
secondary low forming along the front over the Portland area Wednesday
evening...moving it NE through New Brunswick then on into the
Maritimes...moving the cold front trough our area by early Thursday
morning. The European model (ecmwf) maintains a high pressure ridge over the area
through the end of the period..with a new system approaching to
the west. The GFS builds high pressure in for Sat.
Loaded the superblend through the period.
Aviation /00z Saturday through Wednesday/...
near term: occasional MVFR conditions are possible across the
region early tonight...with VFR conditions overnight through
Short term: VFR conditions all sites at the start of the period.
Sky con will slowly fall through the night as the warm front
approaches. MVFR by morning in light snow...falling to IFR in
light to moderate snow by morning. Sky con and visibility will begin to
improve in the afternoon as the front moves east into New
Brunswick. Occasional MVFR conditions are possible Monday. VFR
conditions are expected Tuesday. MVFR/IFR conditions are possible
near term: winds/seas are expected to be below Small Craft Advisory
levels tonight through Saturday...though a few wind gusts up to
25 knots are possible tonight.
Short term: a Gale Warning may be required during the day
Sunday...followed by an Small Craft Advisory for winds and seas through the end of