Area Forecast Discussion
Issued by NWS Caribou, ME-- Highlight Changed Discussion --
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FXUS61 KCAR 011301
Area Forecast Discussion
National Weather Service Caribou ME
901 AM EDT FRI JUL 1 2016
Weak high pressure will move east of the region today. A warm
front will cross the area tonight. A cold front will cross the
.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --9 AM UPDATE...THE AIR IS WARMING QUICKLY UNDER CLEAR SKIES WITH
LIGHT WINDS SO HAD TO RAISE TEMPS SEVERAL DEGREES ACROSS THE AREA
THROUGH THE MORNING HOURS. OTHERWISE, NO MAJOR CHANGES THIS HOUR.
Orgnl Disc: Some lctns are reporting intermittent shallow patchy
fog very erly this morn, but this should burn off shortly aft
sunrise. This will leave msly sunny skies for the region ovr the
majority of the day, with increasing cldnss by eve as a strong
s/wv trof apchs from the great lks. Hi temps will be several
degrees warmer than ystdy with the earlier start of sunshine and
fcst warmer aftn 925-850mb temps, allowing for most lower trrn
lctns N of the immediate coast to reach and exceed 80 deg F.
Cldnss will rapidly thicken this eve, with warm advcn shwrs
breaking out SW to NE across the region ovrngt. Pockets of
elevated CAPE up to 250 to 500 J/KG may result in embedded sct
nocturnal tstms with the rnfl which will result in brief higher
rnfl rates, but given little potential of training of stms, we do
not plan on any enhanced hvy rnfl wording attm. Rnfl amounts
across most of the FA up to Sat morn looks to arnd a hlf inch,
with lcly higher amounts spcly ovr cntrl/wrn high trrn lctns.
Ovrngt lows look to be mild; several deg abv seasonal norms.
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.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
With the passage of the warm front early Saturday morning,
rainfall will end. It will leave the northeast corner of the state
last. The warm front will leave the forecast area in a rather
fleeting warm sector that will end abruptly with a powerful cold
front in the afternoon. Severe weather is a big concern and hinges
on the timing of the cold front. If the cold front is too fast and
the convective temperature is not reached, the area will dodge a
bullet as the dynamics for strong storms are compelling and
probably the best so far this season. Will not add enhanced
wording now due to the timing questions of whether the loaded gun
soundings will materialize in time. The current thinking is that
quick destabilization will occur from late morning into early
afternoon and the cold front will quickly sweep across the area
in the afternoon with potential for supercells. Damaging winds,
large hail, and even a brief tornado would all be possible if the
cold front is slow enough. The eastern border of the state is the
most likely recipient of severe storms and Washington County is
flashing the very best signals for severe. Among the parameters
giving rise to concern include mid- level lapse rates, SBCAPE, 0-6
bulk shear, 0-1 bulk shear, LCLs, BRN, 0-1 EHI and SIGTOR. If
timing doesn`t change with Friday`s 12Z guidance, it may be time
to add the enhanced wording.
Once the front crosses, cooler and drier air will rapidly advect
into the forecast area with lows dropping to the lower 50s. Upper
40s are possible through the Allagash and western mountains. Highs
on Sunday will be quite cool with mid to upper 60s north and low
to mid 70s for Bangor and Down East. These temperatures will be
accompanied by very gusty west winds reaching as high as 35 mph.
These winds and fully leaved trees could cause a few power
outages. Will maintain chance pops for light showers in northern
Aroostook on Saturday night and Sunday. This same region will be
cloudy on Sunday while the southern half of the forecast area
receives more sunshine. Expect clearing skies Sunday night with
lows in the low 50s.
.LONG TERM /MONDAY THROUGH THURSDAY/...
Winds will be strong again on Monday with gusts again hitting over
35 mph with strong mixing and cool air aloft. Highs will be a bit
warmer with less cloud cover. This means low to mid 70s north and
upper 70s to near 80F south. Some guidance suggest an upper level
shortwave could sweep across the area with a few light showers and
will assign slight chance pops. The remainder of the period will
feature a warming trend with humidity creeping back up. Widespread
80s will return Wednesday and Thursday with the exception of
cooler temps on the coast. A cold front will gradually approach
.AVIATION /13Z FRIDAY THROUGH TUESDAY/...
NEAR TERM: VFR xpctd tdy, xcpt for any brief pd of MVFR/IFR vsbys
with patchy fog erly this morn, contg this eve then clgs and vsbys
lowering to IFR region wide across all the TAF sites late Fri ngt
with shwrs and possible tstms.
SHORT TERM: IFR and MVFR cigs will quickly lift Saturday morning
and give way to VFR conditions. However, severe thunderstorms may
impact area terminals in the afternoon with large hail. Otherwise,
VFR conditions are expected later Saturday evening through
Tuesday. Winds will be a significant consideration Sunday and
Monday with gusts potentially reaching 30 kts.
NEAR TERM: No hdlns xpctd attm, but S winds will increase with wv
hts tngt to just under SCA criteria. Wv pds will begin at 7 to 8.5
sec then diminish to 5.5 to 7 sec ovrngt as the wind wv component
increases. Went with about 85 to 90 percent of WW3 wv guidance for
fcst wv hts thru the near term. In addition, marine ST and fog
will likely lower vsbys ovrngt to 1 nm or less by daybreak Sat.
SHORT TERM: Fog will be the first concern over the waters well
into Saturday night. Thunderstorms are the next concern on
Saturday afternoon. With the holiday weekend and influx of
recreational boaters, these thunderstorms could cause issues with
sudden increases in winds and seas. These same recreational
boaters will be at risk again on Sunday with wind gusts reaching
nearly 25 kts and seas hitting around 4 feet. While an SCA
wouldn`t be strongly considered for these conditions in the
winter, public safety necessitate an advisory.