Area Forecast Discussion
Issued by NWS Caribou, ME
FXUS61 KCAR 271418
Area Forecast Discussion
National Weather Service Caribou ME
1018 AM EDT WED JUL 27 2016
A cold front will approach from the northwest this afternoon and
stall across the region tonight into Thursday. The front will push
further south Thursday night and stall near the coast on Friday.
.NEAR TERM /THROUGH TONIGHT/...
1007 am update...
Latest meso analysis showed cold front residing back across
Quebec w/a pre-frontal trof out ahead of it. Already seeing some
dewpoint pooling in NW Maine( mid 60s) w/temps and dewpoints
climbing per the latest obs. So, adjusted the hrly temps and
dewpoint. Decent theta e ridge in Quebec nosing ene. This will be
an aid in tstm development this afternoon. Pops were adjusted the
match the latest radar trend of showing some showers moving across
southern Quebec skirting the nw border. Still anticipating tstms
to develop this afternoon w/gusty winds and hail. Midnight crew
had this well handled. Areas to most affected will be n and nw
areas where best forcing and instability resides. Will continue to
monitor for any changes into the afternoon.
Previous discussion below...
Current sfc analysis places high pressure up the spine of the
Appalachians with ridge axis nosing into CWA as of 06z. Cdfnt is
dropping into Quebec fm James Bay with regional Canadian radars
showing showers and an isold tstorm approx 150 miles north of
Ottawa. Timing of cdfnt is much slower than previously thought
with projected arrival time to international border well aft 00z
tonight and even closer to 06z.
Tda wl be the warmest day of the week with sw flow drawing in H9
temps on the order of +21C acrs nrn zones. Dwpts wl rmn in the lwr
60s with projected highs in the l/m 80s this aftn. Convective temps
progged to be in the lwr 80s and expect that storms wl begin to
fire acrs the Crown of Maine after about 18z as diurnal htg
maximizes. Hv dropped pops down to just isold until aft 21z where
tstorms could become more sctd in cvrg. Frzg levels of around 10kft
combined with 35-40 kts of 0-6km bulk shear may lead to small hail
along with gusty winds, mainly for northern Aroostook this aftn
Expect a dry and sunny day for Downeast as temps appch the 90-
degree mark. Capping inversion arnd 600mb wl prevent storms fm
As the evng wears on expect pcpn to dwindle to just isold showers
due to loss of htg. Patchy fog wl be a possibility once again
tonight as front wl take it`s sweet time mvg into the CWA and
eventually stalling out as guidance indicates sfc low wl ride up
along the bndry sometime in the mrng.
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
A trough of low pressure will be over Eastern Canada on Thursday
as a ridge of high pressure remains along the coast. A weak cold
front will be stalling across the central part of our region on
Thursday bringing a mostly cloudy sky and showers. Soundings are
showing capes over 1000 J/KG, so a chance of thunderstorms,
supported by some weak surface convergence and cooling aloft, will
be included during the afternoon. A very weak upper level
shortwave may also enhance cooling aloft a bit and support
thunderstorm development on Thursday. As the shortwave pushes east
Thursday night, it will push the front a bit further south. The
front will reach the coast overnight Thursday night and stall
along the coast on Friday. this will bring a chance of showers and
some thunderstorms to Downeast areas Friday while northern areas
have partial clearing.
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
The front along the coast will push offshore Friday night into
Saturday as high pressure builds in from the west. Saturday will
turn out a bit cooler and drier across the area with sunshine mixed
with fair weather cumulus clouds. Sunday will be sunny to partly
cloudy and comfortable with high pressure over the region. Dry and
seasonably warm weather should prevail Monday and Tuesday as surface
high pressure takes residence just to our south. A frontal boundary
across eastern Canada will be nearby to the north and may allow a
thundershower to stray into far northern areas either afternoon.
.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
NEAR TERM: Mainly VFR expected today outside of localized low
MVFR/IFR restrictions in fog this morning. Northern terminals may
see -shra/-tsra this afternoon into evening but confidence is too
low to include in terminal forecasts, with the exception of FVE,
at this time.
SHORT TERM: MVFR conditions can be expected on Thursday in
variable low clouds and some showers. MVFR conditions may persist
Downeast Thursday night into Friday with an improvement to VFR
across the north. VFR conditions are likely in high pressure over
NEAR TERM: Winds and seas will be below SCA criteria through
tonight. Fog will reduce visibilities once again late tonight over
SHORT TERM: Winds and Seas are expected to remain below SCA
Thursday through the weekend. Fog will likely reduce visibilities
over the waters Thursday through Friday morning as a result of
warm humid air over the colder waters.