Black Friday Winter Storm Update One
8:24 PM AST Friday 26 November 2021
Special weather statement in effect for:
Fredericton and Southern York County
Significant snowfall tonight and Saturday.
Total 24-hour snowfall forecast: 10 to 15 cm, possibly 20 over higher terrain.
Locations: western and central New Brunswick, including the City of Fredericton.
Remarks: A mixture of wet snow and rain will quickly transition to snow this evening, with widespread amounts of 10 to 15 cm. The snowfall will be heavy at times and may make travel difficult. The precipitation will taper off Saturday evening.
Be prepared to adjust your driving with changing winter road conditions. When clearing snow from your property, remember to take frequent breaks.
Please continue to monitor alerts and forecasts issued by Environment Canada. To report severe weather, send an email to NBstorm@ec.gc.ca or tweet reports using #NBStorm.
000
FXUS61 KCAR 270307
AFDCAR
Area Forecast Discussion
National Weather Service Caribou ME
1007 PM EST Fri Nov 26 2021
.SYNOPSIS...
Intensifying low pressure will lift across the Maritimes
overnight through Sunday. Another low crosses the Gulf of
Maine and exits across the Maritimes by Monday evening. High
pressure will ridge across the region on Tuesday, while another
low moves across northern Maine on Wednesday.
&&
.NEAR TERM /THROUGH SATURDAY/...
1000 PM Update: Latest radar imagery shows the dynamic snow band
across the N gradually diminishing in size and intensity with a
break ovr Cntrl an Downeast areas. However, new deformation
banding is beginning to form and intensify ovr SW coastal ME,
and this area will begin to move into Downeast areas late tngt
as Nrn areas get a brief break in snfl. So far, highest reported
snfl amts range upwards to 4 to 6 inches across the N where
precip at the start msly began as sn with sn ratios since late
aftn were upwards to 16 to 17:1 despite sn falling between 31 to
33 deg F. Sn ratios have come down some to 10 to 13:1 for now.
Otherwise, fcst hrly temps/dwpts were updated into the erly morn
hrs Sat to unchgd ovrngt lows. With little temp fall
experienced across the FA since late aftn, the fall of temps
will be delayed to msly after mdngt when more sig llvl cold
advcn begins.
Prev Disc: No changes were made to the Winter Storm
Warning/Winter Weather Advisory headlines. An intensifying
surface low located along the Maine coast early tonight, will
lift north across New Brunswick overnight along with a closed
upper low. However, whether the track is closer to the Maine/New
Brunswick border, or more across central New Brunswick, is
still uncertain. A more western track would favor heavier
precipitation across eastern portions of the forecast area
tonight. Models indicate an area of focused lift and Q-vector
convergence lifting north across the forecast area tonight with
a developing deformation zone which will help support
precipitation. The location and movement of the deformation zone
will also impact snow accumulations. Precipitation will remain
in the form of snow across northern areas tonight. Based on
critical thicknesses, a rain/snow mix will occur across central
areas early tonight with mostly rain Downeast. Cold air
advection with the deepening low will then allow a transition to
snow southward across the forecast area through the evening.
The vertically stacked system tracks north to the Gaspe
Peninsula Saturday. The most persistent snows Saturday will
occur across northern and central areas with the deformation
zone lifting north. Across Downeast areas, early snow will taper
to snow showers during the afternoon. Additional snow
accumulations are expected Saturday, with the greater amounts
across the north and mountains. Storm total snow accumulations
through Saturday are expected to range from 5 to 10 inches
across northern areas, with 4 to 7 inches across central areas
and 3 to 6 inches Downeast. Gusty winds could support patchy
blowing snow across northern areas Saturday. Low temperatures
tonight will range through the 20s north, to the upper 20s to
around 30 Downeast. High temperatures Saturday will range from
the upper 20s to around 30 north, to the lower to mid 30s
Downeast.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
The nrn 1/2 of the region will still be feeling some effects of
that low lifting across the Gulf of the St. Lawrence on
Saturday night w/some snow showers and breezy conditions.
Additional accumulations of around an inch are possible in the
St. John Valley and back into the N Woods. The central areas
will see less clouds but it will be turning colder as the latest
mdl guidance, such as the GFS and the ECMWF, show some of the
coldest air of the season pouring into the region right into
Monday. Temps on Sunday will be lucky to bust 30F across the nrn
1/2 of the region, while central and downeast areas should
sees/low mid 30s w/a good deal of sunshine and less wind. Weak
high pres building in later Sunday into Sunday night. Clearing,
lighter winds and the cold airmass in place along w/snow cover,
will lead to some pretty cold overnight lows for late November.
We are talking upper single number up across the nrn border and
to the w.
Monday could turn out to be an interesting day. The 12Z mdl
guidance continued to follow its previous runs w/a cutoff low
in the upper levels apchg from the w Sunday night w/increasing
clouds by the early morning hrs on Monday. A sfc low is forecast
to develop just off the srn New England coast and lift nne on
Monday. There are still some discrepancies in regards to
placement and timing of the precip, which looks to be in the
form of snow all the way into the Downeast region. As stated by
the midnight crew, the ECWMF and its ensembles are further w
w/some measurable snowfall, and the 12Z run has stayed the
course. The 12Z Canadian has shifted w as have some of the GEPS
members. The GFS has continued w/an eastwards track, but a light
to the w. We`ll have to see how the latest mdl guidance trends
w/the newer runs over the day or so. For now, decided to trend
to the w, but not as far as the ECMWF and Canadian, as the
latest NBM is more neutral w/its track. So, leaned w/pops up to
60% across the eastern 3rd of the region for Monday and went
w/just snow. If the westward trend does continue, we could be
seeing some more measurable snow w/in the 4 inch range by
Monday evening.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
As stated by the midnight crew, we appear to get into
a more progressive pattern w/a series of systems affecting the
region, albeit fairly weak.
After the low pulls through the Maritimes Monday night, high
pres is expected for Tuesday w/lighter winds, some possible
sun, but still rather cold for the last day of November. Another
fast moving system is shown by the longer range guidance is
forecast to move across northern Maine w/some more snow by
Wednesday. Although, this system looks to deliver light snow
w/minor accumulations. High pres to move in for Thursday w/sun
and drier conditions. For Friday, there is potential for yet
another storm system which could a significant snow as it moves
up along the Maine coast. Still plenty of time to see how this
system takes shape. At any rate, temps through this term are
expected to be near or slightly below normal for the 1st couple
of days of December.......
posted by Advackia at 8:59 PM
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