Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

Area forecast discussion 
National Weather Service Caribou ME
1110 am EDT Mon Oct 24 2016

strong low pressure will remain to our north today. The low will
weaken and move east Tuesday into Wednesday. High pressure will
cross the region Thursday.


Near term /through tonight/...
11:10 am update...a small shortwave crossing the area enhanced
snow showers activity a bit across northern and central areas.
This shortwave will move through to the east early this afternoon.
Some spotty light showers and flurries may continue over northern
and central areas. Raised temps a bit downeast where sunshine has
warmed the air a bit.

Previous discussion...low pressure will continue to spin over
Quebec today and tonight, keeping cold, breezy, and showery
conditions across our region. Northern areas will see isolated to
scattered rain showers redevelop today, possibly mixing with snow
at times. Sky cover will be thickest in the north as well, with
sunshine increasing as one heads south toward the coast. Highs
will range from around 40 in northern Aroostook County to the mid
and upper 40s downeast, though gusty winds will make it feel

Showers should increase in areal coverage across the northern half
of our forecast area overnight as a weak cold front sinks south out
of Canada. Locations along and north of a Danforth to Greenville
line will have the best chances of seeing precipitation, and with
temperatures dipping into the lower to mid 30s, expect at least a
rain/snow mix to occur across much of that region. Any snow
accumulation will be an inch or less; outside of the higher
elevations of the North Woods, don't expect much more than a dusting
to fall overnight. A shower or two will be possible across far
downeast toward the coast, but dry weather will prevail for most.
Lows in these locations will be in the mid to upper 30s.


Short term /Tuesday through Wednesday/...
an east-west upper trof alg with a sfc low departing ewrd from Labrador
into the open north Atlc will still keep cldnss alg with sct rn/sn
shwrs for Tue into Wed spcly across the north hlf of the region, with
sn shwrs msly in th ovrngt and morn hrs with little or no
accumulation. Aftwrds, sfc hi pres from cntrl can will only bring
slow clrg to the region Wed ngt, spcly slow for nrn and ern ptns
of the forecast area. For this reason, ovrngt lows will not be as cold as
they could for spcly the ern hlf of the region.


Long term /Wednesday night through Sunday/...
Thu should be sunnier, with somewhat milder hi temps in the aftn.
Then low pres from the Midwest will bring increasing cldnss to
the region Thu eve and lgt precip by late Thu ngt. Sfc and llvl
925-850mb temps look to be cold enough to support lgt sn or a mix
of lgt sn and rn across the north late Thu ngt into early Fri morn.
Most models then bring milder air both Alf and at the sfc for a
transition to all rn by late Fri morn before more MDT precip
rates arrive. However, the latest model trend with the 00z run
shows sfc low pres re-developing alg he downeast Maine coast by
later Fri as the upper trof sharpens an closes off ovr the Gulf
of ME. This could result in more resistance of llvl cold air to
hold ovr nrn ME on Fri, possibly delaying a chgovr to all rn.
Considering prior model runs were not as bullish with the upper
lvl low and associated dynamics, we will wait for additional model
runs before considering more in the way snfl, spcly considering
any event will have to fight llvl blyr warming from the Atlc. Fcst
total quantitative precipitation forecast from this event will range from a quarter to hlf inch
across the north third of the region to a half to 0.75 inches across
the cntrl and downeast ptns of the region by late Fri ngt with Max
pops Fri in the high likely range.

Aftwrds, models in the longer range disagree in the longer range
with a weaker follow-up low pres system from the Midwest with the
00z opnl GFS tracking it alg the downeast coast Sat ngt and
bringing lgt msly rn to the region and the European model (ecmwf) tracking it
further S and missing the region with any sig precip. For now,
we just mention chc shwr pops for the region Sat into Sat eve
given the model uncertainty.


Aviation /15z Monday through Friday/...
near term: VFR will prevail at all terminals through 00z Tuesday.
Scattered rain and snow showers are possible in the north, mainly
at fve, and these may bring visibility and ceilings down to MVFR
at times. MVFR will become more likely at the northern terminals
overnight as snow showers will become more numerous with the
passage of a weak cold front; occasional IFR will be possible. Bgr
and bhb will remain VFR through 06z Tuesday, then ceilings will
lower to around 2500 ft.

Short to long term: mainly MVFR clgs and attms vsbys with sct
rn/sn shwrs Tue and Wed for nrn taf sites, otherwise, low VFR
clgs for downeast sites. Clgs gradually lifting to VFR for nrn
taf sites Wed ngt, then all taf sites unlmtd VFR Thu and Thu eve.
Clgs then gradually lower late Thu ngt to MVFR and then to IFR on
Fri with rn, which may begin as a mix of rn/sn for nrn taf sites.


near term: 605 am was anticipated, winds have dropped
through the morning hours. Gusts over the inner waters are now at
or below 20 kt, while the outer waters are at or below 30 kt. Have
therefore dropped all headlines for the bays and downgraded the
Gale Warning to a Small Craft Advisory, which was extended out to
8 am Tuesday.

Previous discussion...headlines remain unchanged this
morning. The Gale Warning is in effect until 8 am for the outer
waters, where gusts to 35 kt are still common. The inner waters
are currently experiencing marginal small craft wind gusts, but
will leave the Small Craft Advisory as is for now. Both of these will likely be
able to be downgraded (or removed in the case of the sca) with the
6 am update, but will wait to see trends to make a decision. For
tonight...gusts of 25 to 30 kt look to be the rule over the outer
waters. Inner waters will be marginal, but should mainly be below
Small Craft Advisory levels.

Short to long term: near Small Craft Advisory WV hts ovr outer mzs will begin the
short term, then no hdlns xpctd Tue aftn thru Thu eve. Winds an
wvs will likely reach Small Craft Advisory criteria again late Thu ngt all mzs and
cont into at least Sat morn as southeast winds increase ahead of low
pres apchg from the great lks.


Car watches/warnings/advisories...
Marine...Small Craft Advisory until 8 am EDT Tuesday for anz050-051.



Near term...Hastings/mcb
short term...vjn
long term...vjn

National Weather Service Glossary of Abbreviations