Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 12/29/23
Area Forecast Discussion
National Weather Service Aberdeen SD
540 PM CST Thu Dec 28 2023
.KEY MESSAGES...
- Stratus expected to clear out through this evening, but lingering
or redeveloping fog is possible tonight over the Missouri and James
River valleys.
- Cold frontal passage timing appears to be speeding up, now working
down into the CWA late Friday night into Saturday morning (a.k.a
colder high temperatures Saturday?).
- Mostly dry long term with near to slightly above normal
temperatures.
&&
.UPDATE...
Issued at 539 PM CST Thu Dec 28 2023
Will continue to track and edit the forecast for the low clouds
and fog that are on the diminishing trend early this evening, with
more anticipated on the west side of the Sisseton Hills/James
River Valley.
&&
.SHORT TERM /THIS EVENING THROUGH FRIDAY NIGHT/...
Issued at 133 PM CST Thu Dec 28 2023
At 1 PM CST, high pressure is over the region (centered just off to
the west of the CWA), with light northwest winds (generally 10 MPH
or less). Temperatures are in the 30s, for the most part. Fog and
stratus are slowly dissipating/shifting south and east out of the
CWA; much of north central and part of northeast South Dakota has
cleared off in sunshine this afternoon, while other areas still
remain under some fog and stratus. Low level dry air advection and
WAA is underway across the northern/northwestern third of forecast
zones, expected to continue advecting southeastward across the CWA
through tonight.
Much of the 12Z guidance and BUFKIT soundings data suggests there
will be enough low level dry air advection on north-northwesterly
winds (increasing late tonight into Friday morning) overnight to
scour out the remaining low stratus clouds. HREF guidance appears to
highlight some rather shallow fog potential overnight throughout the
Missouri and James River valleys tonight, despite the low level
drying forecast for tonight. Nocturnal thermal inversion is
potentially strengthened by the low level WAA overnight into Friday.
Somewhat stronger northwesterly mixing potential exists during the
day on Friday, supporting the potential for temperatures to warm up
to or above 40 degrees for some locations.
The RAP model appeared to be leading the charge for trending the
Saturday cold fropa faster, and the 12Z GSM models appeared to be
falling in line with that scenario. Presently, the cold fropa is
progged to extend down into northeast South Dakota prior to 6 AM CST
on Saturday.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
Issued at 133 PM CST Thu Dec 28 2023
A somewhat meridional yet split flowish pattern aloft is expected to
continue over the CONUS, and is predicted similarly among the
various models. About the only time period where some light snow
could occur is Saturday aftn/evening. At that time energy/trof aloft
dig south over the eastern CWA. Bufr soundings indicate enough
lift/moisture to suggest a low end PoP is warranted. After Saturday
evening, pcpn chances look pretty much nil through most of the next
week. The main juicy storm track through the coming week looks to be
over the southern CONUS, quite reminiscent of past El Niño winters.
Temperatures will start off cold Sat/Sun as a cold sfc high
back-door`s the forecast area from the N/NE. Used a mix of
NBM/MOS/NBM 20th percentile for temps. By the middle of next week.
a milder airmass should take over but temperatures are forecast
to only slightly exceed seasonal norms.
&&
.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/...
Issued at 539 PM CST Thu Dec 28 2023
Terminals KABR,KATY,KPIR,KMBG
VFR ceilings and visibility should continue at both MBG and PIR,
with the LIFR ceilings just ending at PIR. Otherwise, at ATY and
ABR, the forecast will be more difficult. Conditions will start
out VFR, but fog will be possible later this evening and
overnight. Have brought down the forecast to IFR at ABR from
02-13, as fog should be more thick near or just to the east of the
site.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...None.
MN...None.
&&
$$
UPDATE...KF
SHORT TERM...Dorn
LONG TERM...TDK
AVIATION...KF
Area Forecast Discussion
National Weather Service Caribou ME
1016 PM EST Thu Dec 28 2023
.SYNOPSIS...
A low pressure complex will track over the Gulf of Maine tonight,
then exit southeast of the Maritimes Friday through Sunday.
High pressure will build toward the region Monday and sink
southwest of the area into Tuesday.
&&
.NEAR TERM /THROUGH FRIDAY/...
1015 pm update...
Regional radar showing precip has made it as far north as
possibly Baxter SP with sleet being reported at MLT at this
hour. Temps are hovering around the 32 degree mark along and
just south of I95 so have bumped the start time of the WWA up
and it is in effect now. With frozen ground and roads washed
clean of any salt potential exists for untreated roads and
bridges to become slippery very quickly tonight. Have slowed
pops by 1-2 hours across the north late tonight as high pressure
and dry air is holding on. 00z NAM is showing a mainly dry day
over nrn Aroostook with low moving south of Nova Scotia and
gives us snow with upr trof approaching tomorrow evening. Not
biting off on this soln though HRRR has slowed down approach of
pcpn until after 15z acrs the St. John Valley. Update to ingest
latest temps/dwpts and progress of rain/freezing rain into the
fcst and did a quick revamp of wx and associated snow/ice
amounts during the storm but revised forecast looking almost
negligible comparatively speaking.
Prev discussion blo...
A complex potentially impactful wintry event expected tonight
into Friday. Travel impacts are possible across the Central
Highlands into portions of the Baxter Region to Southern
Aroostook County tonight into Friday.
Setup...A 500mb nearly cutoff low pressure will drift southeast
over the Ohio River Valley tonight as low pressure deepens to
997mb over the Gulf of Maine tonight south of Nova Scotia over
Georges Bank. Strong high pressure to the north has created
20-30 degree dew point depressions in the St. John Valley and NE
Aroostook County. This is a challenge with moisture trying to
advect northward into the Central Highlands and the County. High
pressure will be NE of the Gaspe Peninsula continuing to pump
dry air southward but will lose its battle into tomorrow morning
as upper level trof at 500mb pivots SE from Quebec. Low pressure
will track NE to the Nova Scotia coastline as the 500mb trof and
secondary weak surface low dives south into Western Maine.
Precipitation will likely taper slightly Friday morning before
increasing again in response to the 500mb trof and secondary
sfc low pressure system. The trof will be sliding towards Maine
heading into the short term as noted below...
Temps...Temperatures will be fall back into the low to mid 30s
from the Bangor region to the Downeast coast where 925mb temps
remain warm with warm air advection aloft. It is here where
temperatures will stay above freezing but cannot rule out
isolated 32F readings in the colder spots of interior Hancock
and Central Washington counties. Across the Central Highlands at
850mb a warm nose will warm temps to +1-2C as surface
temperatures with nighttime strengthening of the CAD fall into
the upper 20s to low 30s but below 32F as dew points likely in
the 29-32F range as well. Across the far north except large dew
point depressions to slowly come together with moistening of the
boundary layer but it will be slow with that strong high
pressure.
Precip...Across the Downeast coast into the Greater Bangor area
expecting precip to remain as rain through Friday with temps
above freezing throughout the column. Cannot rule out some
isolated freezing rain in interior Hancock along and north of
Route 9 corridor and this includes Central Washington County.
Central Highlands north of the Route 6 corridor with light
precip falling through that above freezing 850mb layer and
surface temps below freezing expect a period of freezing rain
or freezing drizzle tonight into Friday. It is here that by
daybreak ice accretion up to one tenth of an inch is possible
making for slick travel on untreated surfaces. Most roads have
no salt residue and will require treatment as freezing rain
falls on colder surfaces. Southern portions of the Central
Highlands along Route 6 will change to rain tomorrow as the
boundary layer warms above 32F. North of Moosehead to Baxter and
Southern Aroostook to perhaps Houlton will remain at or below
32F which will result in freezing rain remaining. As the low
pressure tracks south of Nova Scotia tomorrow and the upper trof
arrives from the NW, modeled soundings in decent agreement the
column will cool resulting in a switch to snow. Tonight into
tomorrow midday across the County north of Houlton there could
be some mixing before changing to snow but totals are very
uncertain given the dry air. Icing across the Central Highlands
before the switch to snow by tomorrow evening will top out in
the 0.1-0.2 inch range for some locations but most locations see
at least a glaze. By late day into the evening expect the column
to continue to cool changing any mixed precip to snow from the
Route 6 corridor northward into the County with snow beginning
to accumulate especially in the North Woods although very light.
Impacts...Mainly travel will be impacted tonight into tomorrow
with roads becoming slick given that most surfaces are
untreated. Ice accretion of 0.1-0.2 inch with light winds is
expected to cause any other issues other than travel. Winter
Weather Advisories have been hoisted in two tiers. The first
one goes from 1AM tonight through 10am Friday for mainly
freezing rain from Dover-Foxcroft to Topsfield. North of here
from the Moosehead Region to Baxter into Southern Aroostook
County we opted to go with a Winter Weather Advisory for
intially freezing rain up to 0.2 inch and then 1-2 inches of
snow on top of it. This advisory goes from 1AM Friday till 10AM
Saturday but again mainly a travel impact event.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
The stronger low pressure system will continue to move off to
the E over the maritimes while the secondary low that has
developer to the west will slowly progress E on Friday night.
Though the trof of cold air should start to work into the
region, the upper level model thickness still shows a layer of
warm air aloft. Thus decided to keep freezing rain in the
forecast for the earlier hours of Friday night, mainly in higher
terrain. As the night progresses, the cold air will dominate,
changing all precip to snow in the north and rain in the south
with a rain/snow line across the Central Highlands. By Saturday,
the upper level ridge should push the low to the E, which will
gradually decrease the precip across the area. Expect light snow
in the north and rain in the south. Temps should hover right
around freezing in the north while the south should see temps in
the upper 30s.
By Saturday night, the ridge should move into the region, with
some remaining snow showers in the north. These snow showers
have the potential to develop into Laurentian plumes with the
strong NW flow and moist low and mid levels. By Sunday, clouds
should start to dissipate with temps hitting near normal.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
The rest of the week should be fairly inactive. A general trend
of the jet stream staying south across the southern United
States. The next system should move through the region on
Thursday in the form of a weak cold front, but the models are
fairly inconsistent this far out. Stayed with the NBM forecast
for this time period.
&&
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
NEAR TERM: IFR over Downeast terminals tonight in rain and low
cigs. This will continue next 24 hours. As precip and low cigs
move north expect that HUL becomes MVFR around 06z, PQI and CAR
around 09z and FVE holding off until 12z. Light fzra expected
at HUL for majority of the day, though may begin to mix with
snow toward end of TAF period. Light snow expected further to
the north though cannot rule out a very brief period of time at
PQI and CAR where -fzdz may occur as precip becomes lighter in
the afternoon.
SHORT TERM: Friday night-Sat...MVFR/IFR, occasional LIFR in
rain/snow. Variable winds 5-10 kts.
Saturday night...VFR/MVFR. Decreasing snow shower chances.
NNW winds around 10 kts.
Sunday...VFR/MVFR. NW winds 5-10 kts.
Sunday night-Tue...VFR. Variable winds 5-10 knots Sunday night,
then NNW winds 5-10 kts Monday.
&&
.MARINE...
NEAR TERM: Small Craft Advisory in effect through 1PM Friday
across all of the coastal waters out to 25nm. NE winds tonight
20-25kt with gusts up to 30kt. Seas becoming 3-5ft tonight with
a period of 5-6sec. NE winds gusting to 30kt will drop below SCA
conditions by afternoon. Seas generally 3-6ft with the highest
seas 20-25nm offshore. Wave period becoming 8-9sec by afternoon.
Tonight expect light rain and patchy fog reducing vsby. Rain
continues to be possible all day tomorrow reducing vsby at
times.
SHORT TERM: Winds and seas should remain below SCA conditions
for this time period.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...Winter Weather Advisory until 10 AM EST Saturday for
MEZ003>006-010.
Winter Weather Advisory until 10 AM EST Friday for MEZ011-031-
032.
MARINE...Small Craft Advisory until 1 PM EST Friday for ANZ050>052.
&&
$$
Near Term...Buster/Sinko
Short Term...LaFlash
Long Term...LaFlash
Aviation...Buster/Sinko/LaFlash
Marine...Buster/Sinko/LaFlash
Area Forecast Discussion
National Weather Service Quad Cities IA IL
518 PM CST Thu Dec 28 2023
.KEY MESSAGES...
- Winter weather advisory continues this afternoon/evening,
with some slick roads and sidewalks for the evening commute.
Some refreeze of water on roads creating icy spots overnight
also a concern.
- Mostly dry conditions and temperatures returning closer to
normal for the last few days of 2023.
&&
.SHORT TERM /THROUGH FRIDAY/...
Issued at 215 PM CST Thu Dec 28 2023
Water vapor imagery and 12z upper air analysis shows the large upper
low that has brought a myriad of weather to the central CONUS since
Sunday night centered over southeast IL. A TROWAL feature behind the
upper low has brought light to moderate snow (visibility 3/4 to 3
statute miles) to the northern half of the CWA this morning. SPC
meso page showed the max wetbulb aloft for much of the morning
just below 0C and model soundings also confirmed a below
freezing profile resulting in all snow falling. Snowfall amounts
from spotters have been between a dusting and 2.5 inches in
Lowden IA and Stockton IL. Road conditions and webcams show
primary roads and Interstates partially covered or just wet,
whereas secondary roads have a little more snow.
This Afternoon/Tonight
Radar trends and latest CAMS show light to moderate snow continuing
across much of the CWA through mid evening. RAP forcing/low level
convergence progs this evening show a weakening trend occurring
around 00z through the rest of the overnight. This is also supported
on the 12z HREF, with snowfall rates less than 0.25"/hr at that
time. With pavement and surface temps just above freezing, not
anticipating much additional accums after 00z tonight. Additional
snowfall amounts now through 6pm will be around an inch, with total
snowfall amounts between a half inch to 3 inches on elevated and
grassy surfaces. Will continue the winter weather advisory for now,
but may be able to be cancelled early. Low clouds and a north wind
overnight will keep temperatures in the lower 30s for much of the
night. With dewpoints also in the upper 20s and lower 30s, there is
some concern for re-freezing of water on area roads tonight creating
some slick spots, especially on bridges and overpasses.
Friday
The upper low continues its slow eastward trek out of the region and
into the Ohio River valley. Clouds will slowly clear out from
northwest to southeast through early afternoon, with a light north
wind. Went near the NBM 50th percentile for highs resulting in
readings in the upper 30s. If clouds linger tomorrow, which is a
possibility temps may be a bit too warm, especially in north central
and west central IL.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
Issued at 215 PM CST Thu Dec 28 2023
The pattern aloft will transition to a northwest flow over the
weekend through early next week. A strong shortwave will move
through the upper Midwest Saturday night-Sunday that may clip our
northeast third of the CWA. Thermal profiles will be cold enough for
all snow. However, moisture will be limited and better forcing
displaced to our north. In the wake of this system, brisk winds look
to bring temperatures down closer to average but still above normal
for the start of the New Year.
The first week of the year will be rather quiet, with an active
Pacific jet keeping the storm track to our south. Dry conditions are
forecast with temperatures rebounding back into the mid to upper 30s
for highs and the upper teens to lower 20s for lows. No real cold
air intrusions are expected for the next 7 days across the
CONUS.
Another system will drop south out of Canada and into the upper
Midwest late next week that may bring more chances of precipitation,
but with timing and location differences this far out will keep a
dry forecast going at this time.
&&
.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/...
Issued at 514 PM CST Thu Dec 28
The slow moving upper low bringing widespread light snow to
eastern Iowa and northwest Illinois will continue to remain in
place through 06Z tonight, then gradually shift east and weaken.
Visibility in light snow and fog will vary between 1 and 3 miles
this evening in all sites, and though accumulation this evening
is generally under 1 inch, this may accumulate on elevated
surfaces including planes. Runways will likely be wet, or a bit
slushy given ongoing treatment in commercial airports.
Cigs will remain IFR tonight, with levels holding in the 500 to
1000 ft range through 12-14Z. After tonight, dry air will slowly
move into the area, first ending the snow, then gradually
lifting the cigs to MVFR through the day Friday. By Friday late
afternoon, some clearing may move into eastern Iowa, especially
near CID.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...Winter Weather Advisory until 9 PM CST this evening for IAZ041-
042-052>054.
Winter Weather Advisory until midnight CST tonight for
IAZ064>068-077-078.
IL...Winter Weather Advisory until 9 PM CST this evening for ILZ001-
002-007.
Winter Weather Advisory until midnight CST tonight for ILZ009-
015>018-024.
MO...None.
&&
$$
SHORT TERM...Gross
LONG TERM...Gross
AVIATION...Ervin
Area Forecast Discussion
National Weather Service Grand Forks ND
945 PM CST Thu Dec 28 2023
.KEY MESSAGES...
- Dense fog continues to impact northwest Minnesota, and is expected
to dissipate from west to east this afternoon.
- Mostly clear and quiet weather is expected Friday.
- A fast moving clipper brings colder air and light snow to the
area Saturday.
&&
.UPDATE...
Issued at 945 PM CST Thu Dec 28 2023
Dense fog continues to expand, resulting in the expansion of the
dense fog advisory. This goes through 6am, but I imagine that
could change. Possibility remains for patchy fog in southeastern
ND as well, but none has developed quite yet. Forecast remains
on track.
Issued at 643 PM CST Thu Dec 28 2023
Fog appears to be back-building west as the sun sets this
evening. Continuing to monitor the need for a expansion of the
FG.Y but that may come later in the overnight. HRRR visibility
suggests it will happen at some point though, at least in the
southern valley. Otherwise, forecast remains on track.
&&
.DISCUSSION...
Issued at 328 PM CST Thu Dec 28 2023
Fog and mist continue to dissipate from west to east this afternoon,
with most areas west of the Red River now seeing mostly clear skies.
Heading into the overnight period, temperatures should be able to
fall into the teens to low 20s, with the coldest temperatures
occurring where skies have completely cleared. Winds remain out of
the west and will be light through the evening and into the
overnight hours.
Heading into Friday, west to northwest winds increase slightly, with
gusts to near 30 mph possible. Portions of the area where ice still
coats trees and power lines could see minor impacts due to tree
branches falling from ice-impacted trees. Overall, this should be
minimal. High temperatures are expected to climb into the 30s, which
will promote the melting of ice, especially with mostly clear skies.
Our next system arrives on Saturday, and will bring a surge of
colder air into the Northern Plains. Very light snow and flurries
are possible; however, there is little in the way of available
moisture, thus any accumulations and associated impacts would be
minimal. Gusty north winds follow this cold front passage, with
gusts up to 35 mph possible much of Saturday afternoon. Highs on
Saturday will range from the upper teens near the International
Border, to near 30 degrees in far southeastern North Dakota.
Sunday through the middle of next week: Look for near normal
temperatures on Sunday, with a return to warmer than average
temperatures from Monday through Wednesday. No strong signals exist
for impactful weather through this period; however, there is a
rather consistent trend toward a pattern change that could take
shape heading into late next week. This would bring much colder
temperatures to the region heading into next weekend and beyond.
&&
.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 519 PM CST Thu Dec 28 2023
FG will continue to bring aviation impacts to the MN TAF sites.
This could possibly expand into the Red River Valley overnight
(FAR) but we will continue to monitor. Winds will shift to more
northerly into Friday morning and increase to around 10 - 15
knots. MN TAF sites will remain cloudy for a lot of the morning
into the early afternoon before clearing out, whereas ND TAF
sites can expect VFR conditions all day Friday.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...Dense Fog Advisory until 6 AM CST Friday for NDZ008-016-027-
030-039-053.
MN...Dense Fog Advisory until 6 AM CST Friday for MNZ001>009-
013>017-022>024-027>032-040.
&&
$$
UPDATE...AK
DISCUSSION...Lynch
AVIATION...AK
Area Forecast Discussion
National Weather Service Goodland KS
821 PM MST Thu Dec 28 2023
.UPDATE...
Issued at 818 PM MST Thu Dec 28 2023
ESTF update to remove mention of fog from previous forecast.
Slightly drier air is now occurring over the western CWA as T/TD
spreads range from 3 to 6 degrees. This combined with the shift
in winds to more westerly has negated fog formation at this time.
UPDATE Issued at 607 PM MST Thu Dec 28 2023
Continuing to monitor NW portions of the CWA for potential fog
development over the next few hours. Areas of concern continue to
be focused on locales receiving the most snowfall from the recent
storm, and where that portion that has yet to melt. As of 01z
Friday, the latest area obs show no signs of fog development.
T/Td spreads remains at least 3 degrees or higher and winds are
slowly becoming more westerly, which could provide enough
downslope effect to stave off fog. While warming is not expected
as skies are clearing this evening, it will be drying of the
airmass. If winds taper off some, fog could ensue, but will
monitor closely.
&&
.SHORT TERM...(This evening through Saturday night)
Issued at 100 PM MST Thu Dec 28 2023
Through Tonight: Patchy dense fog may develop over a limited
portion of the area for a few hours after sunset this evening,
mainly along and north of I-70 in eastern CO and adjacent KS
border counties (Burlington-Goodland north to Idalia-St. Francis)
between 6-10 pm MST /01-05 UTC Fri/. A differential heating -- or,
in this case, snow melting -- gradient exists near the CO/KS
border this afternoon, on the western periphery of afternoon
stratus (at 19 UTC, Yuma was CLR and Wray was OVC017). The
aforementioned stratus is anticipated to rapidly dissipate or
recede eastward around or shortly after sunset. The thought here
is that.. the rapid onset of strong radiational cooling over (and
adjacent to) portions of the snow pack that experienced
appreciable melting.. i.e. central and western portions of Yuma
and Kit Carson Counties where insolation was unimpeded by cloud
cover.. may rapidly foster the development of dense fog within an
hour or two after sunset. HRRR surface vis forecasts suggest
that, if dense fog develops.. it would be spatiotemporally
limited in nature (as described above).
Fri-Sat night: Primarily a temperature forecast. Expect dry
conditions, benign weather and a warming trend associated with
pronounced synoptic subsidence /height rises/.. as the expansive
upper level low over the central CONUS finally shifts eastward to
the Appalachians (Fri) and Atlantic (Sat). With mostly clear skies
and light winds, daytime highs and overnight lows will largely be
a function of snow cover. With this in mind, areas situated along
and north of I-70 in eastern CO and far northwest KS (where snow
depth is greatest) are most likely to experience a muted warming
trend /relatively cooler temperatures/.
.LONG TERM...(Sunday through Wednesday)
Issued at 1135 AM MST Thu Dec 28 2023
Sunday...500mb pattern features an upper ridge axis along the
Continental Divide with low pressure to our east and west of the
Rockies. Any cloudiness will be limited to cirrus level with dry
weather expected. Cooler air backs into the area with high
temperatures falling below normal (30 year average 41-43 degrees)
into the 30s. Low temperatures also fall slightly below normal
into the 10 to 17 degree range.
Monday...the trough west of the Rockies Sunday reaches the
Continental Divide overnight with increasing mid and high clouds
moving over the area from the west-southwest. Presently, dry
weather is expected. High temperatures rise a few degrees from
Sundays highs with readings in the middle 30s to middle 40s. Low
temperatures will generally be in the middle teens to lower 20s.
Tuesday...this mornings model guidance is showing the upper
trough axis moving across the area during the day with a slight
northwest component in the axis during the night, allowing for a
bit drier air aloft to move in. Presently, the better 850-500mb
moisture and qpf remains south of the Kansas border so we`ll
continue with a dry forecast. High temperatures are forecast to be
in the upper 30s to middle 40s with low temperatures in the
middle teens to around 20.
Wednesday...upper level ridging moves over the area, ahead of a
low pressure system that is forecast to move into the southwestern
part of the country by 12z Thursday. Very little moisture to work
with for any precipitation so dry weather looks good. High
temperatures are forecast to be in the upper 30s to middle 40s
with low temperatures in the middle teens to lower 20s.
Thursday...similar to Mondays nights scenario, Wednesdays upper
low is forecast to track east into Arizona/New Mexico through the
period. Moisture and precipitation with this system stays well
south of Kansas and Colorado so no need to mention any
precipitation at this time. High temperatures continue in the
upper 30s to middle 40s with low temperatures in the middle teens
to lower 20s.
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 333 PM MST Thu Dec 28 2023
For KGLD, the main wx focus during the forecast period will be
the potential for dense fog to form from about 01z-05z. Conditions
could drop to IFR during this time with visibility less than a
mile and ceilings below OVC010. After 05z Friday, VFR. Winds,
west-northwest 10-15kts.
For KMCK, MVFR fog is possible from 02z-06z with visibility
dropping to 2sm and ceilings around BKN015, otherwise VFR
conditions will ensue. Winds, west-northwest around 10kts.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JN
SHORT TERM...Vincent
LONG TERM...99
AVIATION...JN
Area Forecast Discussion
National Weather Service Indianapolis IN
911 PM EST Thu Dec 28 2023
.Key Messages...
- Chances for rain and snow through Friday with best chances for
snow in the NW and W portions of the forecast area
- A coating of snow is possible, mainly western parts of the CWA
- Seasonable temperatures persist through the next week
&&
.Forecast Update...
Issued at 911 PM EST Thu Dec 28 2023
- Scattered light rain showers changing to snow overnight.
Surface analysis this evening showed a trough of low pressure
stretching from southern Michigan to eastern IL. This feature was
associated with a large upper level low pressure system that was
found over Central Indiana. Radar this evening shows scattered rain
showers, with some very light snow mixed in across mainly western
parts of Central Indiana. Temperatures and dew points across the
area were in the middle 30s.
Models overnight suggest a slow SE progression of the upper low and
the associated surface trough across Central Indiana. HRRR suggests
best light precipitation will be focused over points mainly in the
Wabash Valley overnight, before reaching southern Indiana by
morning. Pops will still be needed throughout the forecast area,
with the highest values in the Wabash Valley with gradually lowering
values toward the east. Look for the lightest amounts of
precipitation east.
An additional challenge overnight is precipitation type. Forecast
soundings show a gradually cooling column overnight. Initially a
small layer of temperatures above freezing appear near the surface,
allowing our ongoing precipitation to be mainly rain. However, as
cooling goes on through the night, the forecast soundings show a
column completely below freezing. This would be indicative of a
change over to snow. Thus will work that change over during the
overnight hours. Any accumulations should be less than 0.5 inches.
&&
.Short Term...(This evening through Friday)
Issued at 331 PM EST Thu Dec 28 2023
Current radar and observations show increasing coverage of
precipitation this afternoon as a surface low develops over northern
Indiana. Rain is the predominant precip type, but snow is already
being reported in a few spots near far northwest portions of central
Indiana as evaporational cooling has cooled temperatures a few
degrees.
The surface low is expected to slowly drift south into the
area this evening/overnight with precipitation increasing in
coverage. Snow will likely mix in at times as temperatures gradually
cool through the night. In addition, evaporative cooling from higher
precipitation rates will help cool temperatures slightly. The best
chance for snow will be across west/southwest portions of the area
where minor snowfall accumulations are expected, mainly on grass and
elevated surfaces. Marginal surface temperatures will likely limit
travel impacts. However, use caution if driving as any localized
heavier snow bands could lead to slick spots, especially on elevated
surfaces. Look for temperatures to drop into the low-mid 30s
tonight.
Widely scattered light precipitation will likely linger into Friday
with the aforementioned surface low still centered over the area.
Expect some light snow to be mixed in around daybreak, but subtle
diurnal warming should change precip type to all rain later in the
day. Gloomy conditions combined with light precipitation will keep
highs in the upper 30s to near 40F.
&&
.Long Term...(Friday night through Thursday)
Issued at 331 PM EST Thu Dec 28 2023
The long range will start off with some light mixed precipitation as
a low exits to the east. Model soundings point towards low clouds
and dreary conditions persisting into the weekend with potentially
pockets of sun shining through. Another wave could again bring
scattered light precipitation on Sunday but would only expect
drizzle and flurries at this time should anything form. Latest y
mix in at a few TAF sites overnighguidance is suggesting less
than a 15% chance and confidence is not high enough to increase
from guidance.
Surface high pressure for next week will bring higher confidence
that it will be dry for at least the first few days of the new year.
Towards the end of the forecast period, some models are hinting at
another system that could bring some more precipitation, potentially
for central to eastern parts of the forecast area. There is a bit
too much noise for much confidence at this time.
Temperatures will stay relatively consistent through the period with
highs from the upper 30s to low 40s and lows from the mid 20s to
near freezing.
Beyond day 7, some hints in ensemble guidance of a trend towards a
more active pattern. While not a strong signal, a period of cooler
than average temperatures are possible as well.
&&
.Aviation...(00Z TAF Issuance)
Issued at 601 PM EST Thu Dec 28 2023
Impacts:
- Light rain or drizzle likely through the evening
- Snow may mix in at a few TAF sites overnight, mainly near KHUF/KBMG
- IFR/LIFR conditions are expected.
Discussion:
Little change from the ongoing TAF Forecast. Upper level low
pressure over southern IL and Southern IN will continue to slowly
drift southeast through the period. Extensive lower level clouds
and cigs below 1K ft were found across the TAF sites and much of the
region.
Rain showers across the area are expected to continue this evening
and as temperatures fall slightly through the night, snow may mix in
with the precipitation. Best chances for snow will be at LAF and
HUF, with lesser chances at IND and BMG. All of this will result in
continued IFR or worse conditions overnight with low cigs and low
visibility.
As the low drifts farther away on Friday afternoon, winds will shift
to the west or northwest and cigs should improve to MVFR.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Update...Puma
Short Term...Melo
Long Term...KF
Aviation...Puma
Area Forecast Discussion
National Weather Service Pittsburgh PA
652 PM EST Thu Dec 28 2023
.SYNOPSIS...
Weak high pressure will bring a relatively quiet night as a
cooling trend begins over the Upper Ohio River Valley. A trough
of low pressure will bring rain and snow showers Friday night
and Saturday.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
KEY MESSAGES:
- Temperatures will be cooler overnight but still about 10F
above normal
- It will be relatively quiet with nothing more than a brief,
light shower
Update...
Upper low over southern Indiana will make little forward
progress overnight. With the earlier shortwave out of the area,
subsidence has eased and heights will begin to fall this
evening. Scattered showers are possible across the
western/central portions of the forecast area before dissipating
late tonight. Cold air advection (oddly from the southwest...),
will allow overnight temperatures to drop into the 30s
areawide.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY/...
KEY MESSAGES:
- Temperatures will be closer to seasonal normals during the day
Friday and Saturday.
- Rain and snow showers will return but snow accumulations will
be limited to the ridges and mainly above 2,000 feet MSL
Upper low crosses Kentucky during the morning and then reaches
West Virginia in the late afternoon. The low then accelerates
into southeast PA and eventually New England Friday night as it
phases with a trough digging into Quebec.
The coldest 850 mb air of roughly -6C should be in place Friday
before warm advection starts from the northwest Friday night.
The combination of the cooling from the upper trough and
increasing westerly flow will result in showers especially over
the ridges Friday night. Warm advection and a surface trough
could force rain/snow showers elsewhere Friday night into
Saturday.
Things start to dry out Saturday as 500 mb heights rise about
70 meters as a fast moving ridge builds into Upper Ohio River
Valley. Guidance has lingering precipitation in the morning
likely from warm advection.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
KEY MESSAGES:
- Temperatures will be near seasonable normals during the day
but remain about 10 degrees above normal at night.
- A quick-hitting clipper will reintroduce precipitation chances
for New Years Eve.
The next upper trough moves from MN to WI Saturday night and
then into MI on Sunday, bringing 50 meter height falls to the
forecast area. The trough passes overhead on Monday and then
continues to the east coast.
Associated surface low rather weak and tracks across MI toward
western NY Sunday and New Year`s Eve. While 850 mb temperatures
remain around -4C Sunday before dropping Sunday night, the
boundary layer looks unstable which could result in some rain
showers and a convective afternoon boundary layer to start. Most
of the precipitation would change over to snow Sunday night and
there could be accumulations with increasing west to northwest
upslope flow as the upper trough passes overhead.
500 mb heights rise about 140 meters with the next upper ridge
passage Monday night and Tuesday.
Confidence drops in the forecast by Wednesday and Thursday with
the next trough moving across the Great Lakes area. Timing
between various ensemble guidance is different by at least a
day, and none of the solutions looks particularly wet so the
impacts to the forecast will be minimal. Heights have been
consistently a tad below normal on the GEFS during this time so
would expect temperatures near to slightly below normal. Current
NBM deterministic highs are 2-4F above normal Wed/Thu and with
low confidence will not adjust them.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
Generally low VFR, with patchy MVFR, stratocu cigs will
continue tonight with an upper low centered across Indiana.
Current satellite trends, along with RAP and HRRR model output,
shows some potential for partial clearing overnight for airports
south of FKL and DUJ as weak surface ridging builds across a
portion of the Upper Ohio Valley region. Probabilistic forecast
from both the SREF and NBM also support a scattering out of the
stratocu overnight.
Cold air aloft and low convective temperatures should support a
rapid redevelopment of the stratocu Friday morning, though cig
heights should be mainly low VFR. Airports across Ohio should
see more MVFR cigs in closer proximity to the upper low.
MVFR restrictions should overspread the area again Friday
evening, as the upper low begins to phase with a northern stream
trough, and a cold front spreads rain and snow showers across
the region.
.OUTLOOK..
Restrictions, along with rain and snow showers, are expected
Friday night and Saturday as the cold front completes its
passage. Cig restrictions are likely to continue through Sunday
ahead of approaching low pressure. Restrictions in rain and
snow showers are likely again Sunday night and Monday with the
crossing low/cold front. VFR returns Tuesday under high
pressure.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
PA...None.
OH...None.
WV...None.
&&
$$
SYNOPSIS...Craven
NEAR TERM...Craven/Rackley
SHORT TERM...Craven
LONG TERM...Craven
AVIATION...WM
Area Forecast Discussion
National Weather Service Blacksburg VA
945 PM EST Thu Dec 28 2023
.SYNOPSIS...
Through Saturday night, the lower Mid-Atlantic will remain
under the influence of a deep low pressure system over the
central United States that is drifting slowly eastward. As this
system passes overhead Friday night, the associated cold air
will cause rain showers to change to snow showers across the
mountains. Snow showers will persist through Saturday night
before coming to an end with accumulations greater than an inch
along the higher ridges above 3000 feet.
&&
.NEAR TERM /THROUGH FRIDAY/...
As of 940 PM EST Thursday...
Key Messages:
-Rain changing to snow Friday.
-Light snow accumulations above 3000 feet.
Latest short range guidance still has southwest Virginia,
northwest North Carolina, and southeast West Virginia until
after 4AM/10Z Friday morning. Cloud cover has been increasing
since 6PM and will continue to fill in overnight.
In locations that have been clear during the evening,
temperatures have cooled into the lower 30s to lower 40s. As the
cloud cover expands, the temperature drop will slow down. Have
lowered minimum temperatures for tonight based on current
observation trends.
As of 610 PM EST Thursday...
Made some minor adjustments in temperatures for this evening
into tonight utilizing the latest surface obs, their trends and
blended in the NBM. In general, expected low temperatures
tonight to range from the mid 20s in the mountains to the mid
30s in the Piedmont. As the upper low in the Midwest approaches
tonight, cloud cover increases overnight into Friday morning.
The deeper moisture arrives Friday with rain and snow showers.
The latest HRRR looked a little slower with the onset of the
precipitation. Kept the precipitation early Friday morning just
along the western mountains. The NAM appeared too robust with
moisture Friday morning. More changes later tonight.
Previous Discussion:
As of 1250 PM EST Thursday...
The upper level low that has plagued the central Plains and
Midwest the last several days will move over Virginia/North
Carolina tomorrow. Low level thicknesses support initial
precipitation as light rain. 85H temperatures cool through the
day to have elevations above 3000 feet changing over to snow
showers early in the afternoon. Around 4p, lower elevations will
see rain changing to snow. Temperatures remain warm enough for
any precipitation east of the Blue Ridge should stay as a
liquid. Snow amounts through early evening will range from a
trace in the valleys to one to two tenths for elevations above
3000 feet.
For this afternoon into tonight, a lee trough will have light
west winds over the mountains and foothills and a southwest wind
over the piedmont. There will be more sun than clouds today
with increasing cloudiness overnight. The exception would be
southeast West Virginia where clouds and a few showers/sprinkles
will persist into early evening.
Temperatures will warm into the 40s across the mountains and
50s east of the Blue Ridge this afternoon. Lows tonight will dip
into the upper 20s to mid 30s. Cooler temperatures expected
tomorrow as the low passes overhead. Max temperatures across the
mountains will range from the mid 30s to lower 40s, which may
occur by noon. East of the Blue Ridge should see temperatures
peaking in the afternoon from the mid 40s to lower 50s.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
As of 100 PM EST Thursday...
Key Message:
1) Mountain snow showers arrive Saturday...
Closed upper low currently situated over the Midwest will
slowly pivot east by the end of the week as northern stream
energy moving through Canada captures the upper low and
eventually takes it into New England.
As the upper low passes overhead, could see a few rain showers
east of the mountains on Friday night and into Saturday.
Mountain snow showers possible over southeast West Virginia and
far southwest Virginia. As the low passes, flow becomes more
northwesterly during the day Saturday and upslope mountain snow
will continue through Saturday night. Upslope snow will be done
by Sunday and a weak ridge between the next incoming trough
passes overhead, allowing for high pressure to briefly build for
Sunday. This will provide widespread 40s and low 50s across the
region.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
As of 100 PM EST Thursday...
Key Message:
1) High uncertainty in the extended forecast for any potential
storm systems...
A rather chaotic weather pattern is setting up for the extended
with quite a bit of upper-level energy rotating through the
CONUS. This leads to wild variations between deterministic model
runs and therefore, the extended is mostly weighted on ensemble
guidance.
Overall drier weather returns with intermittent waves of energy
passing across the region. This pattern would support the
potential for low pressure development within the east, which
could spread moisture across the area. Model guidance hints at a
potential system early next week. Anything beyond saying there
is a potential system is complete guess work.
With expected troughing over the east, cooler temperatures can
also be expected over the extended period through early next
week.
&&
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
As of 635 PM EST Thursday...
VFR conditions will continue this evening into tonight. An
upper low will travel southeast tonight into Friday. As the low
center approaches, clouds will increase tonight into Friday. The
upper level low will bring precipitation to mainly the
mountains late tonight into Friday. This will mainly be a
rain event, changing to snow Friday afternoon. Flight
conditions will remain VFR east of the Blue Ridge. Ceilings
across the mountains should lower to MVFR levels Friday morning
while western slopes could drop to IFR. VFR visibilities for
most expect western slopes could lower to IFR as rain changes to
snow.
Moderate confidence in ceilings,visibilities and winds
during the taf period.
EXTENDED OUTLOOK...
Upslope rain showers will transition to snow showers by Friday
evening, with this activity persisting into Saturday night.
East of the Blue Ridge, flight conditions will be VFR behind the
cold front in the westerly downslope flow.
Sunday night and Monday, a low pressure system will bring a
chance of snow and MVFR flight conditions to the mountains.
Drier conditions expected Tuesday into Tuesday night. Isolated
to scattered MVFR rain and snow showers are possible on
Wednesday.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...None.
NC...None.
WV...None.
&&
$$
SYNOPSIS...RCS
NEAR TERM...AMS/KK/RCS
SHORT TERM...BMG
LONG TERM...BMG
AVIATION...KK/RCS
Area Forecast Discussion
National Weather Service Topeka KS
447 PM CST Thu Dec 28 2023
.KEY MESSAGES...
- Low clouds and very light wintry precipitation possible again
tonight/early Friday AM
- Warming up through Saturday, then dry cold frontal passage
early Sunday
&&
.DISCUSSION...
Issued at 200 PM CST Thu Dec 28 2023
A brief window of clearing has finally allowed for some diurnal
heating early this afternoon; however, diurnal cu has already
begun to fill in behind the clearing line as a response, and
additional high clouds will also be rotating through the area
this afternoon and this evening -- so heating will be limited
to just a couple more degrees across the region.
Additional stratus is already making its way south across
Nebraska, and will arrive this evening. With a similar setup
and quite a bit of local moisture still hanging around, would
expect a pretty similar profile again tonight and early Friday
morning with enough moisture to squeeze out some light wintry
precipitation. HREF probabilities for accumulating precipitation
are still pretty low, but with a decent little wave rotating
down the back side of the upper low and saturated low-levels,
the chance for non-accumulating snow or very light sleet is
higher than PoPs would represent. Have added some flurries for
now across eastern portions of the forecast area, but will need
to continue to monitor near-term forecast soundings for the
potential for freezing drizzle, across especially southeastern
portions of the area where saturation is a little shallower.
The troublesome upper low finally makes some eastward progress
Friday, and should allow skies to clear by mid- to late-morning.
Temperatures should rise into the 40s in spite of strengthening
cold air advection, and sunshine should make some decent
progress melting lingering snow cover across north central and
central KS. Haven`t added anything into the gridded forecast
yet, but will need to assess the potential for some freezing fog
early Saturday across the areas where snow cover still exists
today.
Warming continues Saturday, then a cold frontal passage is
expected late Saturday night into early Sunday morning. The
front should be dry, but will knock temperatures back to a few
notches below normal for Sunday through early next week.
Ensemble spread then starts to increase by middle next week as
longwave troughing rebuilds over the eastern CONUS and northwest
flow intensifies across the central states. Cluster analysis
shows slightly colder temperatures with more amplified
solutions, as well as a slightly wetter pattern near or just
south of the forecast area at the end of the forecast period.
LREF members start to show some possibility of wetter weather
returning in the Jan 5-6 timeframe, which for now is just
beyond the end of the forecast period.
&&
.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 447 PM CST Thu Dec 28 2023
Satellite shows MVFR stratus moving south. A linear extrapolation
would bring CIGS around 1100 feet into the terminals between 00
and 01Z. There is good agreement between the RAP and NAM for
this stratus will mix out from west to east Friday with VFR
conditions developing at TOP and FOE between 18Z and 20Z. Can`t
rule out a flurry overnight but the bigger concern would be for
the moisture to be so shallow that if there is precip, it may be
more of a freezing mist. Confidence is to low to include at
this time.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
DISCUSSION...Laflin
AVIATION...Wolters