Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 11/28/21
Area Forecast Discussion
National Weather Service Duluth MN
538 PM CST Sat Nov 27 2021
.DISCUSSION...(This evening through Friday)
Issued at 426 PM CST Sat Nov 27 2021
Summary: Gusty northwest winds are expected tonight as a weak
cool front moves through the Northland. A clipper system will
bring accumulating snow to region Sunday night and Monday.
Additional light snow chances arrive Wednesday.
A deep trough aloft and associated lobe of vorticity were located
over eastern Manitoba late this afternoon per RAP analysis and
GOES-East IR imagery. The trough and vorticity will dig
southeastward tonight with the trough closing off over northwest
Ontario by 06Z. Strong winds aloft on the western periphery of the
low along with low-level cold air advection should keep the
boundary layer mixed overnight with gusty northwest winds of 10 to
25 mph with gusts of 20 to 35 mph expected. A few snow showers or
flurries are not out of the question, especially over north-
central Minnesota and the Arrowhead. The favorable fetch and warm
surface water temperatures on Lake Superior (around 42 F, +5.5 C,
per satellite observations from 11/25) should be sufficient for
lake-effect snow showers over the northern portions of the
Bayfield Peninsula and northern Iron County, with a better chance
of snow showers farther east into Upper Michigan. The main
question for the LES potential is residence time over the water
and turbulent mixing of drier air aloft. With gusty winds expected
over the water, parcels may not linger long enough over the
southwest arm of Lake Superior to realize enough heat and moisture
flux to support lake-effect snow. Will continue to carry PoPs and
accumulating snow for now, but later shift may end up reducing
amounts should snow showers be slow to develop or under-perform.
The upper low will drift southeast of the area on Sunday and wind
gusts will gradually subside. Attention then shifts to a clipper
system which will bring our next chance of widespread accumulating
snow to the Northland Sunday night through Monday night. There
are still minor timing differences among the deterministic and
ensemble models, which limits our precision in timing to 3-hour
increments starting late Sunday evening. Think well see a
frontogenetic band of snow along the elevated warm front,
oriented northwest to southeast, move across our area. Light snow
should move into northwest Minnesota during the late afternoon or
early evening and arrive in central and north-central Minnesota
after 9 PM. Light snow will move eastward with time, resulting in
snow covered and slippery roads in time for the Monday morning
post-holiday commute. Were carrying a broad area of 1 to 3
inches of accumulation through Monday afternoon with some lake-
enhancement/lake-effect snow possible thereafter into early
Tuesday morning for portions of Iron County. An additional inch or
two isnt out of the question for the northwest Wisconsin
snowbelt areas by the time the snow wraps up.
Temperatures for the remainder of the week will oscillate between
slightly above and slightly below normal as northwest flow
remains in place aloft. A progressive pattern of shortwave troughs
will alternate between cold air advection and warm air advection
regimes every 24 to 36 hours through next weekend. A more
organized clipper may bring another round of snow to the Northland
Wednesday and Wednesday night with a few inches of accumulation
possible. Another clipper may bring a dusting up to an inch or two
of snow Thursday night and Friday with scattered snow showers
possibly lingering into the weekend.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 538 PM CST Sat Nov 27 2021
Starting out with VFR across the terminals but an upper-low and
cold air advection will dive south-southeast into the area
tonight. MVFR ceilings upstream across eastern Manitoba and far
northwest Ontario will arrive tonight. Have kept BRD scattered for
now, but opted for MVFR ceilings elsewhere. Scattered snow
showers or flurries are possible tonight and have added VCSH to
INL and HIB with this update. The cold air advection tonight
should be able to mix the boundary layer and produce gusty winds
as an axis of stronger winds aloft on the western periphery of the
upper-low moves over our area. The axis of the jet should be far
enough aloft to preclude LLWS at this time. Models are notoriously
fast in clearing ice clouds in cold air advection regimes. So,
have ended the wind gusts at the terminals between 11Z and 14Z.
Will hold onto the MVFR ceilings for a little while longer even as
the forecast soundings indicate skies will clear. All sites
should be VFR by late afternoon at the latest.
&&
.MARINE...
Issued at 426 PM CST Sat Nov 27 2021
Strong northwest winds of 10 to 25 knots with gusts of 25 to 30
knots are expected tonight into Sunday morning. Occasional gale-
force gusts to 35 knots are possible for the waters of the North
Shore from around midnight through 9 AM. An upgrade to a Gale
Warning for those areas may be needed later tonight if it appears
the gale-force gusts will be more persistent than currently
forecast. Winds will weaken by Sunday afternoon and will gradually
back southwesterly ahead of an approaching area of low pressure.
Light snow will push eastward over the water Sunday night and
Monday and may produce visibility of less than 1 mile at times.
Temperatures over the water may be warm enough to melt some of the
snow into rain. West and northwest winds in the wake of the area
of low pressure will be gusty late Monday night through Tuesday.
As of the time of this discussion, gusts should be 20 knots or
less, near the threshold for Small Craft Advisories. If later
forecasts indicate higher wind speeds than currently expected,
Small Craft Advisories will likely be needed.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 21 29 20 35 / 10 0 70 70
INL 20 27 17 32 / 10 10 70 70
BRD 18 32 22 40 / 0 0 60 20
HYR 19 31 17 37 / 10 0 70 70
ASX 23 32 18 36 / 20 10 50 70
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
LS...Small Craft Advisory until 4 PM CST Sunday for LSZ121-140>148-
150.
&&
$$
DISCUSSION...Huyck
AVIATION...Huyck
MARINE...Huyck
Area Forecast Discussion
National Weather Service Norman OK
827 PM CST Sat Nov 27 2021
...New UPDATE...
.UPDATE...
Issued at 817 PM CST Sat Nov 27 2021
Latest RAP and CAMs bring the rainfall further to the south and
east and out of our forecast area, which are consistent with the
radar reflectivity trends. As a result, removed rain from the POP
and Weather grids slightly earlier for our western north Texas
counties and our Oklahoma counties bordering the Red River. No
other changes have been made to the forecast.
&&
.SHORT TERM...
(This afternoon through Sunday)
Issued at 1154 AM CST Sat Nov 27 2021
A mid-level low will move west to east across central Texas through
this evening. There is a fairly definite northern edge to the
moisture and the rain with this system. Mid-level flow will increase
from the northwest over Oklahoma later today, and along with a
passing cold front, will keep a distinct northern edge to light
rain. Likely pops will be confined to the southern tier of our TX
counties with slight rain chances just north of the Red River for
today. The cold front now moving through northwestern Oklahoma is
expected to clear central Oklahoma by late afternoon and
southeastern Oklahoma around midnight. Only slightly cooler air is
expected to take temperatures down closer to late-November averages
on Sunday with breezy north winds subsiding around mid-day Sunday.
In fact, this airmass will move eastward toward Arkansas by Sunday
afternoon allowing south winds to develop in western Oklahoma.
&&
.LONG TERM...
(Sunday night through next Friday)
Issued at 1237 PM CST Sat Nov 27 2021
Summary:
Most of the coming week will bring us above normal temperatures
(highs in the 60s and lower 70s) with little to no rain chances.
Meteorological Analysis:
The overall synoptic pattern will be northwest flow with an upper
level ridge impinging from the west for most of the long term
period. Models indicate a shortwave moving through Tuesday
/ Wednesday bringing only the slightest of cool downs. Moisture will
remain too far south for us to have any rain chances with this
system.
The forecast becomes a bit more uncertain toward next weekend
(starting Friday) when a minority of ensemble members try to push
off the ridge to our west. There`s enough of a signal to at least
forecast lower temperatures Saturday and Sunday, but any rain
chances still look to be below mentionable probabilities.
Day
&&
.AVIATION...
(00Z TAFS)
Issued at 527 PM CST Sat Nov 27 2021
Mid-level clouds and light rain over our far southern counties
will shift back south before 03Z or so, leaving decreasing
cloudiness behind. North winds behind a cold front will continue
overnight, then decrease during the day on Sunday, then (in the
west) shift to light southerly or (in the central and east) light
and variable.
&&
.UPPER AIR...
Issued at 118 PM CST Thu Nov 25 2021
No Upper Air Flights are planned.
&&
.PRELIMINARY POINT TEMPS/POPS...
Oklahoma City OK 37 58 39 69 / 0 0 0 0
Hobart OK 35 61 37 71 / 0 0 0 0
Wichita Falls TX 39 64 38 73 / 20 0 0 0
Gage OK 29 61 37 74 / 0 0 0 0
Ponca City OK 33 57 36 69 / 0 0 0 0
Durant OK 41 62 37 69 / 10 0 0 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...None.
TX...None.
&&
$$
SHORT TERM...68
LONG TERM....14
AVIATION...23
Area Forecast Discussion
National Weather Service Sacramento CA
217 PM PST Sat Nov 27 2021
.SYNOPSIS...
High confidence that dry weather will continue over
the next 7 days. Expect cool and locally foggy mornings in the
Valley and mild afternoons.
&&
.DISCUSSION...
Visible satellite is showing mostly clear skies across interior
Northern California this afternoon under high pressure. Ensemble
guidance is in extremely good agreement that high pressure will
remain over California through the upcoming week. Under this
pattern, dry weather will persist with above normal daytime
temperatures and generally light winds. Daytime temperatures will
range from the mid 60s to low 70s across the Valley and 50s to 60s
in the mountains and foothills, which is around 5 to 20 degrees
warmer than the daily normal for this time of year. Overnight
temperatures will be chilly in the Valley (40s) and mild in the
foothills (upper 40s to mid 50s). Fog and low stratus chances
are possible in the late evening through early morning hours in
the Valley, though HREF and HRRR indicate fog could be more
localized in nature. -HEC
&&
.EXTENDED DISCUSSION (Wednesday THROUGH Saturday)...
Cluster analysis shows strong ensemble agreement that high
pressure will continue into next weekend over California. Forecast
remains very similar to the short term with dry conditions and
above normal temperatures prevailing. -HEC
&&
.AVIATION...
VFR conditions predominate the next 24 hours. Areas of MVFR
conditions develop overnight in BR. Local IFR/LIFR is expected in
the Central Valley, generally south of KRBL from 12Z thru about
18Z. The best potential for patchy fog will again be over the
northern San Joaquin Valley. Surface winds will be mainly light
and variable with wind gusts under 10 kts.
&&
.STO WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$