-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KCAR 221338
AFDCAR

Area Forecast Discussion
National Weather Service Caribou ME
938 AM EDT Tue Aug 22 2017

.SYNOPSIS...
Low pressure will approach from the west later today. The low
will track to our north tonight into Wednesday as it brings a
cold front across the area.

&&

.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
940 am update...
Bndry conts to lurk somewhere in the vicinity of nrn Maine with
dwpts well into the 60s at all but the St. John Vly tho winds
are out of the south at all locations. Front wl lkly shift north
as sfc low currently sitting acrs east-cntrl Ontario tracks
closer this aftn. Vry little dvlpmnt being seen on radars this
mrng with the exception of convection tracking acrs Ontario and
upstate NY ahd of advancing s/wv. Hv backed off on pops for this
aftn as rain on ern side of convection is dissipating as it
heads east. Only evidence of front is area of stratus dvlpng
acrs nrn Maine. Expect a warm and muggy day acrs the CWA this
aftn.

previous discussion
High pressure will continue to slide to the east of the eastern
seaboard through tonight, while low pressure tracks to the
northwest of the region. Very warm and humid air will continue
to drawn across the region today, as a frontal boundary across
northern most Maine early this morning moves back to the north
as a warm front. Expect partly to mostly sunny skies today,
along with unseasonably warm temperatures. Showers and
thunderstorms are expected to develop across western areas late
this afternoon in advance of an approaching cold front from the
west. High temperatures today are once again expected to range
from the low to mid 80s across much of the area away from the
immediate coast.

The cold front will continue to approach the region from the
west this evening, with increasing chances for showers and
thunderstorms, as forcing increases in advance of the
approaching front. Despite the lack of significant surface based
cape tonight, the atmosphere will be highly sheared, with 0-6 km
shear values expected to be in the 40 to 50 kt range. This will
result in the potential for gusty winds in any thunderstorms.
Storm Prediction Center continues with a marginal risk of
thunderstorms across mainly northern and western portions of the
forecast area today. In addition to the gusty wind potential,
another concern will be with regard to locally heavy rainfall.
Forecast soundings show deep moist profiles with precipitable
water values ranging from 1.5 to 2.0 inches, along with dew
point temperatures in the mid to upper 60s. Showers and
thunderstorms will begin to diminish from west to east late
tonight as the cold front continues to move east across the
region. Patchy fog can also be expected tonight. Lows tonight
will continue unseasonably mild, ranging from the mid to upper
60s.
-- End Changed Discussion --

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
Shwrs and any remaining tstms alg with patchy fog should move
msly E of the Rgn by Wed aftn behind a cold front with only
nominal additional rnfl. Behind the front, sfc dwpts should
fall into the 50s with hi temps being lmtd to the 70s across the
N.

Cooler and dry conditions should then spread across all of the
FA Wed ngt as winds decrease ovrngt. Thu and Thu ngt look to be
msly fair and cooler, with prtl cldnss and isold shwrs possible
across the N half during the aftn and erly eve hrs as upper lvl
s/wv energy moves into the FA from Srn QB. Any shwr activity
should dissipate by late Thu ngt with the loss of day tm
htg/instability.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
Models in the long range keep upper lvl troffiness ovr the Rgn
Fri thru the weekend and even perhaps into erly next week. Of
the longer range models, the GFS is the most aggressive with
keeping an upper lvl low ovr the the area with more in the way
of implied day tm/erly eve shwrs each day.

The 22/00z ECMWF and CANGEM models indicate more ewrd movement
of the upper low into the Can maritimes by late weekend and
erly next week implying drier conditions for the Rgn. Using
CPC`s 6 to 10 day outlook which is calling for increased odds of
below normal precip for our area as a tie breaker, we kept max
PoPs in the slgt chc category each day/erly eve for now until
the models better agree on a specific s/wv for higher PoPs. High
and low temps will be at to below avg in the long range spcly
across the N and Cntrl due to continual llvl cool advcn and day
tm prtl cld cvr.

&&

.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
NEAR TERM: VFR expected at the terminals most of the daylight
hours. Showers and thunderstorms are expected to develop from
west to east late this afternoon, and then continue to spread
east across the remainder of the region tonight. Patchy fog is
also expected to develop tonight, with widespread IFR developing.
Could see LIFR conditions developing vicinity of Bar Harbor
terminal with very moist air coming in off the Gulf of Maine,
with low stratus and fog expected to impact the field.

SHORT TO LONG TERM: IFR conditions in shwrs and patchy fog erly
Wed morn across all of the TAF sites should improve rapidly to
VFR behind the cold front by Wed aftn and cont so Wed ngt thru
Sat.

&&

.MARINE...
NEAR TERM: Winds/seas will gradually increase today, reaching
small craft advisory levels tonight. A small craft advisory has
been issued from this evening into Wednesday, except for the
intra coastal zone. Visibility is expected to decrease to 1 to
3 nm in areas of fog, along with developing showers and
thunderstorms tonight.

SHORT TO LONG TERM: SCA conditions ovr the outer MZs along with
areas of fog across all of our waters Wed morn should improve by
Wed aftn, with any remaining patchy fog dissipating by Wed eve
behind a cold front. Winds and wvs should then remain below SCA
thresholds thru the remainder of the late week and weekend. Went
below WW3 wv guidance values spcly Wed morn where we only went
with about 75 percent of the guidance attm given the warm
season hi bias due to ovr estimation of sfc wind speeds in a
srly sfc wind regime. Primary wv pds will increase from arnd 5
sec Wed to arnd 10 sec by late in the week as the wv type
becomes longer pd swell.

&&

.CAR WATCHES/WARNINGS/ADVISORIES...
ME...None.
MARINE...Small Craft Advisory from 8 PM this evening to noon EDT
     Wednesday for ANZ050-051.

&&

$$

Near Term...Duda/Farrar
Short Term...VJN
Long Term...VJN
Aviation...Duda/Farrar/VJN
Marine...Duda/Farrar/VJN