Area Forecast Discussion
Issued by NWS Caribou, ME
FXUS61 KCAR 271338
Area Forecast Discussion
National Weather Service Caribou ME
938 AM EDT Mon Mar 27 2017
High pressure will move east of the area tonight as low pressure
approaches from the Great Lakes. Low pressure will cross the
area Monday into Tuesday.
.NEAR TERM /THROUGH TONIGHT/...
935 AM Update:
Latest radar reflectivity showing first batch of precipitation
in the form of light snow currently exiting northern Aroostook
County. Another area of precipitation was currently moving into
central and downeast portions of Maine associated with
approaching short wave . KCBW 88D Correlation Coefficient was
indicating mixed precipitation occurring with Bangor currently
reporting freezing rain. Winter Weather Advisories remain up for
the entire area into this evening for a wintry mix. Have updated
grids to freshen up pops/temps/dew points based on latest
observations but no major changes at this time.
Low pressure is currently passing to the west of New England as
strong high pressure moves away to the east. This is resulting
in over running precipitation spreading across the region. Snow
in coastal areas is expected to quickly change to mixed
precipitation this morning then rain along the immediate
coastline while mixed sleet and freezing rain will continue just
inland from the coast. Snow will change to mixed precipitation
in western and central areas this afternoon then this evening in
the far northeast. Have used a 50/50 blend of the Nam and GFS
for temperature grids. For precipitation type have used the
precipitation from thickness tool run on a 50/50 blend of the
NAM an GFS and using 33 degrees as the cutoff temperature for
mixed/rain. For snowfall amounts will use snow ratio blender run
on the NAM using the Cobb Method. Expect a mix of light
Freezing rain and sleet tonight.
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
Sfc low currently ovr the Great Lakes wl spread east and be located
north of New England by 12z Tue. Expect pcpn to be ongoing at the
start of the short term as s/wv ripples acrs the state ahd of
ejecting Hudson Bay trof. Locations acrs Downeast wl lkly see
drizzle and/or frzg drizzle Tue mrng as moisture rmns bhnd
under inversion fm departing sfc low. Mixed pcpn wl be possible
north of Downeast ahd of next sfc low. By late mrng, temps look
to rise enuf to be all rain north of a Dover-Houlton line with
only far reaches of the St. John Vly experiencing mixed pcpn in
Sfc low and assoc bndry mv thru CWA on Tue night with pops dropping
off fm west to east to slgt chc by Wed mrng. All med range guidance
agree on low rmng well to the south of Nova Scotia on Wed with only
isold-lochc pops expected acrs the nwrn zones in the aftn as H5 trof
swings thru the state. Expect maxes on Wed to be similar to Tue
with mins Wed night slightly colder than prior nights.
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
Brief upr lvl ridging wl bring quiet wx to the CWA thru the end of
the week. The next question centers arnd pcpn for Saturday with GFS
diving upr low well to the south acrs the Mid-Atlantic while EC and
CMC bring it thru New England. This, in turn, plays a significant
role in where sfc low ultimately mvs with GFS mvg it south of Cape
Cod while the others bring it into the Gulf of Maine albeit at
different times. Hv gone abv Superblend for Sat with hichc acrs far
swrn zones drg the day with confidence not high enuf to go lkly at
this point. Temps thru the end of the pd wl lkly be abv normal.
.AVIATION /13Z MONDAY THROUGH FRIDAY/...
NEAR TERM: Expect IFR conditions through tonight.
SHORT TERM: IFR expected on Tue in mixed precip across northern
terminals and drizzle/low clouds at BGR and BHB. Expect
conditions to improve to MVFR at all terminals Wed morning.
High pressure will be building into area Thur afternoon with VFR
NEAR TERM: Have used a 50/50 blend of the Nam12 and GFS for
sustained wind speeds. For Waves: The primary wave system is
currently long period southerly swell (1-2 feet/8 seconds).
Expect southeasterly wind wave to build this morning (4-5 feet/5
seconds by noon) as low pressure passes to the west of New
England. East southeasterly wind wave will continue to build
this afternoon into the evening reaching a maximum of 8-9
feet/7-8 seconds by mid to late evening. Seas will begin to
subside late tonight as low pressure develops in the Gulf of
Maine weakening the pressure gradient. Have used the Near Shore
Prediction System for wave heights as most of fetch area will be
confined to the NWPS Domain and boundary conditions from the
WWIII look reasonable. Will keep timing of SCA as is.
SHORT TERM: Cannot rule out SCA levels persisting into early Tue
morning but after this time seas and winds will remain below SCA
criteria until Wed evening.
ME...Winter Weather Advisory until 10 PM EDT this evening for
Winter Weather Advisory until 8 PM EDT this evening for MEZ029-
MARINE...Small Craft Advisory from 10 PM this evening to 3 AM EDT
Tuesday for ANZ050>052.