Area Forecast Discussion
Issued by NWS Caribou, ME
FXUS61 KCAR 281957
Area Forecast Discussion
National Weather Service Caribou ME
357 PM EDT SAT MAY 28 2016
Weak high pressure will build down from Canada tonight. A warm
front will lift north of the area later Sunday into Sunday night
bringing showers to the region.
.NEAR TERM /THROUGH SUNDAY/...
A cold front lies draped somewhere along the Downeast coast this
afternoon. In addition, a sea breeze is evident on satellite
imagery and in coastal observations. Cherryfield is now down to 74
degrees after topping out at 82 degrees around noon. We`re still
anticipating showers and isolated thunderstorms to develop this
afternoon in the Bangor region down to the coast. Current SB CAPES
are running 1000+ J/kg in far southwestern Penobscot County, as
per the latest mesoanalysis from SPC. This combined with the cold
front and sea breeze should be enough to spark some convection.
Cumulus fields have been increasing over the past couple of hours,
so shouldn`t be too much longer for showers to develop. Once this
occurs, the latest HRRR shows the activity initially drifting
southeast toward the coast, but the precipitation will then lift
back northward along the sea breeze front once it becomes
established. Any thunderstorms that develop will be capable of
producing small hail and heavy rain. Showers will wind down later
this evening as daytime heating is lost.
For the remainder of tonight into Sunday...Weak high pressure
tries to build in tonight, then the cold front will lift back
north as a warm front late Sunday. Lingering moisture will allow
patchy fog to develop across our central and southern areas,
particularly along the coast. Further north, there could be a
brief clearing this evening, but high clouds will spread in from
the west quickly overnight. Showers will also spread eastward
later tonight out ahead of the warm front as it progresses
northward. These showers will eventually spread over northern
Maine Sunday morning, with the most concentrated activity over
western and central Aroostook County. Further south, particularly
south of Millinocket, the showers will be more spotty. Both the
GFS and the NAM indicate some elevated instability across the
north as well, so wouldn`t be surprised to see a few thunderstorms
during the afternoon. Highs will be cooler than today, especially
in central and Downeast areas where highs will be some 10 to 15
degrees cooler than today. Northern Maine will top out in the
lower to mid 60s, while southern areas will be in the mid 60s to
around 70. Cooler along the immediate coast where they`ll be lucky
to hit 60.
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
Initially...shwrs topping the upper ridge from QB prov will cont
ovr msly Nrn/Cntrl ptns of the FA Sun ngt...then remnant shwrs
from the trop system currently just SE of the Carolinas will
clip the Srn ptn of the FA on Mon...with perhaps enough
instability for aftn TSTMS. With highest trop PWATs from the
Bahamas area in excess of 1.50 inches ovr the S hlf of the FA
attm...we mention heavy downpour wording with tstms Mon aftn...but
this could be pessimistic...spcly if deep trop moisture remains S
of the FA. Overall...6 hrly QPFs do not look to be that high
attm...but bears watching for possible heavier rnfl meso-scale
features spcly on Mon.
Some clrg will be possible spcly ovr the Srn two thirds of FA
Mon ngt as the mid lvl s/wv moves E of the FA...taking trop
moisture with it. Tue will begin msly fair...but a s/wv movg E
from Cntrl Can will bring a chc of shwrs to msly Nrn and Cntrl
ptns of the FA later Tue aftn into erly Tues eve. With very lmtd
CAPES...we mention isold tstms with greater than 25 percent chc
PoPs...with lgt 6 hrly QPF amounts.
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
Behind the last exiting s/wv from cntrl Can...skies should clr
ovrngt Tue with fair and near seasonal hi temps on Wed and Thu.
The next chc of shwrs will be later Fri into Sat as s/wv trof
system from the midwest begins to move ENE toward the FA. Max
PWATs possibly in excess of 1.50 inches could mean sig rnfl with
this system...but for now given that this is days 6 and 7 in the
outlook...we lmtd max PoPs to the hi chc category for now.
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
NEAR TERM: At the northern terminals, VFR conditions will
continue to prevail overnight, though local MVFR/IFR in patchy fog
is possible at times. However, IFR will become more likely after
12z Sunday as widespread showers with isolated thunderstorms
spread over the area. The southern TAF sites, meanwhile, will be
VFR this evening and then drop to MVFR and possibly IFR after 05z
in areas of fog. This will persist until 12z Sunday and then
ceilings will lift to MVFR and eventually VFR by the afternoon.
SHORT TERM: LIFR and IFR conditions xpctd across the FA Sun ngt in
shwrs and fog...then improving to MVFR by Mon aftn into Mon ngt
with shwrs/tstms diminishing Mon ngt. conditions should improve to
VFR on Tue and cont thru Thu.
NEAR TERM: No headlines will be needed over the waters through
the remainder of the weekend. The main concern for the period will
be reduced visibility in areas of fog into Sunday morning.
SHORT TERM: No high probability pd of SCA winds/seas are xpctd...
xcpt perhaps Mon ngt...where a brief pd of SCA wv hts may occur
with with a below SCA WSW wind fetch. Low vsbys in fog could be
problem Sun ngt into Mon morn as moist tropical air flows nwrd ovr
the cold Gulf of ME waters.