Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 02/19/23
Area Forecast Discussion
National Weather Service Goodland KS
340 PM MST Sat Feb 18 2023
.SHORT TERM...(This evening through Sunday)
Issued at 301 PM MST Sat Feb 18 2023
Current satellite shows mid to high level cloud cover continuing to
stream across the region from the southwest. RAP 500mb analysis
shows west-southwesterly flow with forecasts of the NAM and GFS
showing a shift to more zonal flow as an upper level trough
approaches from the northwest and a lee trough begins to push
eastward. Temperatures top out today in the upper 30s to upper 40s
and overnight lows drop into the mid-teens to mid-20s.
Another lee trough develops and heads east-southeast as the upper
level trough swings through and shifts flow out of the northwest
Sunday night into Monday. Expect similar temperatures tomorrow as
were experienced today, perhaps only slightly warmer due to
decreased cloud cover and continual melting of the snowpack.
Temperatures will continue to warm on Monday into the mid 40s to mid
50s.
.LONG TERM...(Tuesday through Saturday)
Issued at 1230 PM MST Sat Feb 18 2023
Tuesday...the 500mb flow begins the period from the northwest,
backing to the west during the day then to the southwest during the
night as a large upper level low and its trough organize over the
intermountain west. This mornings model guidance has the better 850-
500mb moisture for precipitation north of the area through the day.
Last night and this mornings NBM update has silent pops for the
daytime hours which is generous. During the night, moisture in
the 850-500mb layer increases across the northwest 1/3 or so of
the forecast area ahead of the upper trough and as a result we
have some slight chance and low chance pops for some light rain
mixing with or changing over to light snow. Little if any
accumulation is currently expected. High temperatures are forecast
to be in the lower to upper 50s which is close to the better
performing temperature guidance from the past 7 to 15 days. 850mb
temperatures of 8C to 13C and MEX guidance would suggest higher
temperatures then currently forecast. Low temperatures in the
middle teens to upper 20s.
Wednesday...the upper trough to our west is forecast to remain
stationary through the day, ejecting a piece of energy across the
area during the night. GFS/GEM/ECMWF 850-700mb relative humidity
forecasts remain fairly high during the day as a cold front moves
through. Mid level moisture lifts northeast and out of the area
during the morning with another batch moving into the western
part of the forecast area during the afternoon. Overall, I still
think slight chance to likely pops are a bit overdone. Should any
snow fall, current forecasts from the NBM and other guidance show
zero to 0.2 of an inch, highest across the northwest 1/2 of the
area. For the overnight hours, we`ll continue with slight chance
to likely pops through midnight for additional light snow
accumulation up to perhaps one half inch. Todays temperature
guidance isnt as cold as the previous shift with high temperatures
in the lower 30s to middle 40s. 850mb temperatures from the
GFS/GEM/ECMWF average about -7C across the northern CWA to +3C
across the south at 18z with slowly cooling temperatures through
the afternoon. Low temperatures are forecast to range from -6F in
Yuma, CO to +5F in Hill City, KS. Wind chill readings during the
night are currently forecast to be in the
-7F to -22F range, coldest in Yuma county.
Thursday...the 500mb flow remains from the southwest with another
deep trough trying to organize over California/Nevada. Dry weather
is currently forecast through the day with a slight chance of light
snow during the evening per NBM and GEM models. GFS/ECMWF relative
humidity forecasts at 850-700 and 700-500mb are drier and not
supportive of any precipitation. Arctic air continues to pour into
the area from the north with GFS/GEM/ECMWF 850mb temperatures
ranging from -14C across the north to -7C across the south...about
7C to 10C colder compared to Wednesday. NBM high temperatures range
from the upper teens to around 20 degrees across the north to 30
degrees across the south. Low temperatures fall into the single
digits above zero with wind chill readings in the single digits
below zero.
Friday...the GFS/ECMWF/GEFS models push the upper trough axis east
toward the Continental Divide through the period. Dry weather is
currently forecast. 850mb temperatures from the GFS/ECMWF rise 13C
to 16C compared to Thursday supporting much warmer temperatures in
the 30s to middle 40s. Low temperatures are forecast to be in the
middle teens.
Saturday...the GFS/ECMWF models move the upper trough axis into the
northern plains southwest into New Mexico during the day. A lack of
moisture through 500mb supports a dry forecast at this time.
GFS/ECMWF 850mb temperatures drop about a few degrees C but high
temperatures from the NBM are higher than Friday. I`m thinking
current high temperatures in the lower 40s to lower 40s may be
optimistic for some but based on typical mixing to 850mb some of the
forecast area highs are on track.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 340 PM MST Sat Feb 18 2023
KGLD...VFR conditions are expected through the period. A west
wind up to 10kts at taf issuance at taf issuance will continue for
much of the night, veering to the northwest at similar speeds
during the afternoon Sunday.
KMCK...VFR conditions are expected through the period. A light
southwest wind at taf issuance will veer to the west at speeds up
to 10kts from 05z-15z then veer to the northwest at speeds up to
12kts through Sunday afternoon.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...CC
LONG TERM...99
AVIATION...99
Area Forecast Discussion
National Weather Service Green Bay WI
811 PM CST Sat Feb 18 2023
New Information added to update section
.UPDATE...
Issued at 810 PM CST Sat Feb 18 2023
Warm advection continues this evening ahead of a southern stream
system across the central Plains and a cold front over the
Dakotas. Mid and high clouds from the southern stream system are
spreading across Wisconsin this evening. Persistent south flow and
cloud cover overhead will keep temps mild overnight with lows in
the middle 20s to near 30 by the Lakeshore.
Rap analysis and upstream soundings indicate a very dry airmass is
present across the northern Mississippi Valley and western Great
Lakes region this evening. Despite warm advection occurring, think
models are too aggressive developing low clouds overnight across
north-central WI. Dewpoint depressions fall significantly behind
the front over the western Dakotas. This front will arrive over
north-central WI on Sunday morning, which seems like a better
approximation for the timing of low cloudiness.
In the end, the only modest change to the going forecast was to
adjust sky cover.
&&
.SHORT TERM...Tonight and Sunday
Issued at 242 PM CST Sat Feb 18 2023
Southerly flow and WAA aloft brought back some high clouds for the
region this afternoon, gradually reducing the sunshine for much
of the region through the early afternoon. High temperatures
remain on track to be in the upper 30s to low/middle 40s for the
mid afternoon.
South to southwesterly flow will continue into the overnight
hours tonight which will keep low temperatures warmer than last
night. Lows tonight will range from the middle to upper 20s for
most of the area, almost ten degrees warmer than last night.
An alberta Clipper system will pass across the north during the
day Sunday. Weak CAA could produce at least a few light snow
showers across the far north, but qpf for any snow during the day
will likely be fairly minimal with all the dry air at the surface
to overcome. High temperatures will be fairly similar to today,
with highest in the middle 30s to lower 40s.
.LONG TERM...Sunday Night Through Saturday
Issued at 242 PM CST Sat Feb 18 2023
Three systems are expected to move through the region through the
middle of next week, with each likely to have greater impact than
the previous.
Sunday night...
A weak clipper low pressure system will pass through Canada; well
north of the forecast area, but an associated cold front will
move through during the afternoon and evening. The best chance of
snow will be across north central WI, aided by lake-effect in the
Lake Superior snowbelt. However, a secondary are of light
precipitation may develop along the cold front as it moves through
our southeast counties in the evening. Expecting a dusting a half
inch in far north central WI, with little or no accumulation
elsewhere.
Monday afternoon and Monday night...
A second clipper low is expected to impact the region Monday
afternoon and night. This system will be stronger, track farther
south, and have a more potent short-wave in association with it.
Expect accumulating snow to overspread the northwest half of the
forecast area late Monday afternoon, and the rest of the region in
the evening. Total accumulations of 1-3 inches are expected
northwest of a line from Wausau to Antigo to Iron Mountain, with
a dusting to an inch farther southeast. This low will likely
result in some travel impacts for north central and parts of far
northeast WI. Minor lake-effect snow showers will continue into
Tuesday morning before ending.
Tuesday night through Thursday...
Models show significant isentropic lift and mid-level
frontogenetic forcing Tuesday night, along with upper level
divergence in association with the RRQ of a jet streak. The
forcing may briefly weaken Wednesday morning before ramping up
again later Wednesday. A band of snow is expected to set up
across mainly central and east central WI, including the Fox
Valley, with potential for 2-4 inches in some locations.
A surface low will track from the Central Plains to the Great
Lakes region Wednesday night into Thursday, though there are
still differences in the track (ECMWF farther south than the
GFS). In addition, a potent short-wave and associated deformation
zone are expected to move into the region on Thursday. The ECMWF
Extreme Forecast Index (EFI) shows potential for high impact
winds, QPF and snowfall during this period, and the majority of
ensemble members and operational models indicate significant QPF
amounts of 0.5 to 0.8 inches. Heavy snow, strong winds and
blowing/drifting snow look like a real possibility, but this
system has yet to be sampled by the radiosonde network over the
CONUS, and there are differences in the track, so prefer a
cautious and gradual ramp-up with messaging.
Rest of the extended...
A weak system is progged to push through the area Friday night
into Saturday, accompanied by a chance of light snow.
&&
.AVIATION...for 00Z TAF Issuance
Issued at 524 PM CST Sat Feb 18 2023
- As a clipper passes north of Lake Superior on Sunday, a weak
cold front will move across northern WI. Only spotty, light
rain and snow showers will be possible on Sunday afternoon.
- Low level wind shear remains likely to develop late this
evening into the overnight hours at all taf sites.
- Ceilings will remain VFR with only mid and high clouds until
the front arrives on Sunday morning. Then MVFR clouds are
expected to spread from northwest to southeast across north-
central WI on Sunday. Delayed the arrival of these lower
ceilings by several hours. These clouds will likely struggle to
reach the Fox Valley and Lakeshore, but did bring them into
GRB/ATW in the afternoon.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE.........MPC
SHORT TERM.....Uhlmann
LONG TERM......Kieckbusch
AVIATION.......MPC
Area Forecast Discussion
National Weather Service Melbourne FL
953 PM EST Sat Feb 18 2023
...New UPDATE, MARINE, AVIATION...
.UPDATE...
Issued at 951 PM EST Sat Feb 18 2023
Made some adjustments to the forecast with latest guidance this
evening, mainly winds and PoPs, but over all nothing major. The
PoP forecast for tonight and Sunday remains troublesome, with
pretty high confidence in development of a weak surface trough
just offshore by the afternoon, but less agreement how much rain
and where. The HRRR and ARW continue to promote isolated showers
along the coast, at best, as the trough gets pushed eastward
before it can deliver much rainfall, while the NAM Nest and FV3
are much more aggressive with scattered to even numerous light
showers moving onshore and inland as far as the Orlando metro
before getting kicked off to the east. Given the uncertainty,
opted to be generous with 20 pct PoPs along the coast and inland
to I-95, especially later in the afternoon Sunday, but no further
inland since the NAM and FV3 are not initializing well. As for
winds, nudged the forecast closer to the hi-res models since the
blends were smoothing out too many smaller scale features, such as
the afternoon sea breeze development south of Melbourne.
Otherwise, partly to mostly cloudy skies, a gentle breeze, and
overnight lows ranging from the low 50s up north to the low 60s
down south.
&&
.MARINE...
Issued at 951 PM EST Sat Feb 18 2023
Tonight...Boating conditions continue to improve, but remain
hazardous in the Gulf Stream due to seas up to 8 ft, including
portions of the Treasure Coast nearshore waters. A Small Craft
Advisory remains in effect for the offshore waters until 10 AM,
and the Treasure Coast nearshore waters until 4 AM. High pressure
over the SE U.S. shifts ENE, loosening the pressure gradient
across the local waters. Winds 10-15 kts nearshore and 15-20 kts
offshore continue to ease, becoming 5-10 kts nearshore and 10-15
kts offshore, while veering from NE to E. Seas in the Gulf Stream
up to 8 ft subside to 5-7 ft by morning. Seas closer to shore 3-5
ft.
&&
.AVIATION...
(00Z TAFS)
Issued at 951 PM EST Sat Feb 18 2023
VFR conditions prevail through the TAF period as high pressure
builds over ECFL. Light easterly winds become VRB at times Sunday,
especially inland. Coastal terminals switch to onshore in the
afternoon with the sea breeze. VCSH at coastal terminals starting
early Sunday morning as a weak surface trough developing offshore
increases rain chances. BKN-OVC VFR CIGS building northward
through the night, reaching inland terminals by morning.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 66 56 75 58 / 0 10 20 0
MCO 71 58 81 60 / 0 10 10 0
MLB 72 62 79 60 / 10 10 20 0
VRB 74 64 82 61 / 10 10 20 0
LEE 71 55 79 58 / 0 0 10 0
SFB 71 57 80 59 / 0 10 10 0
ORL 72 59 81 61 / 0 10 10 0
FPR 73 64 80 63 / 10 10 20 10
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...None.
AM...Small Craft Advisory until 4 AM EST Sunday for AMZ555.
Small Craft Advisory until 10 AM EST Sunday for AMZ570-572-575.
&&
$$
SHORT TERM...Haley
LONG TERM....Weitlich
AVIATION...Haley
Area Forecast Discussion
National Weather Service Marquette MI
532 PM EST Sat Feb 18 2023
.SHORT TERM...(Remainder of today and tonight)
Issued at 1222 PM EST SAT FEB 18 2023
This morning has been marked by mostly cloudy skies and temperatures
in the 20s. As we progressed through the morning though, ridge axis
moving through resulting in increasing subsidence has helped to
clear skies out across much of the south and west. Some spots that
have seen the clear skies have warmed into the low 30s. Overall, its
been a nice day across Upper Michigan.
For the remainder of the afternoon, expect skies to continuing
clearing as ridge axis moves overhead. Temps are expected to warm up
into the 30s across the region with the warmest spots being in the
south-central where some mid-30s are expected. An upstream shortwave
and surface low is expected to continue pressing eastward across the
northern Plains tonight, with WAA occurring over the forecast area
ahead of the clipper, resulting in slowly increasing cloud cover.
With the cloud cover expected to be slow some spots could dip into
the teens, but generally expecting overnight lows to be in the 20s
across the forecast area.
.LONG TERM...(Sunday through Saturday)
Issued at 247 PM EST SAT FEB 18 2023
Key Messages:
-Cold front and trailing LES Sun PM/Mon AM, snow highest in Baraga
terrain
-Clipper low and snow chances Monday into Tuesday, again with
trailing LES
-Potential for impactful system late week
-Continued pattern of cooler temps and shortwaves followed by LES
An active pattern is set up for the UP for the long term forecast,
with broad troughing over Canada giving a good setup for multiple
shortwaves of varying strengths to pass through the CONUS. The first
is a fairly subtle shortwave supporting a clipper system Sunday
night into Monday morning, followed by a more well defined shortwave
passing through the Upper Great Lakes Monday. The wave with the most
potential impact arrives towards the late week, though great
uncertainty exists on key details that could impact the location of
the resultant low and what environmental variables are available
that translate into snowfall impacts. Beyond the late week, this
wavy pattern continues, though confidence continues to fall with the
Butterfly Effect of every passing system making predictive
confidence in the details of the longer term forecast very low. The
other impact of Canadian broad troughing is prevailing northerlies
that can lead to lake effect snow in the wake of passing shortwaves.
Starting with Sunday, warm air advection and southerly surface flow
ahead of a subtle shortwave will bring daytime highs above freezing.
While the 06Z GEFS progs a low that deepens from 1007 to 1002 mb as
it follows the north shores of Lake Superior during the day Sunday,
mid to upper level dry air will limit system snowfall to light
showers at best, per the 12Z WRF ARW and HRRR runs. Temperatures
around freezing will allow for some ptype mixing including some
fzdz, though with QPF limited by before, any ice will be a light
glaze or less. Following the cold front, 850mb temperatures fall
almost 10 degrees C in 12 hours, reaching well into the negative
teens C by 09Z Monday. Amazingly, Lake Superior has almost no ice to
inhibit lake effect snow for February, and surface level moisture is
supportive for lake effect snow bands out of the north and northwest
late Sunday into Monday. However, as soundings indicate the moist
layer is only generally below 5kft and only marginally into the DGZ,
both QPF and snow ratio will be limited despite the supportive
thermal profile.
Lake effect snow will rapidly end Monday morning around 12Z as winds
turn southerly ahead of the next system. While this is technically
an Alberta clipper as the shortwave originates from the Alberta
Rockies and digs south, the magnitude of the shortwave is abnormally
strong, and this will support a low pressure passing through the
CWA. The 06Z GEFS has the mean low center over Marquette at 994 mb
06Z Tuesday, with ensemble centers from Isle Royale to Menominee.
The 00Z EPS is a bit slower and not as sure about the center`s
location, with centers ranging from Milwaukee to the MN Arrowhead,
with the Canadian ensemble being a mixed bag of both solutions. A
more southerly track might give more snow, but even the more
northerly low track could give at least advisory levels of snow
given the vigorous lift in the DGZ expected with deep moisture
expected. Following tropa, northwesterly flow and cold advection
aloft once again provide a helpful thermal profile for lake
enhancement at first followed by pure lake effect snow for the NW
bands. The lake effect will be capped in intensity by broad
anticyclonic flow, though the thermal and moisture profile should be
supportive enough for at least light lake effect showers to persist.
The most interesting of the snow systems expected to impact the UP
during the long term forecast will be arriving in the late week
period. It is a fragile setup that will depend on not only the
results of the previously discussed troughs, but the interaction of
a pair of troughs that pass through the CONUS Wednesday through
Friday morning. The first is a deep trough over the Baja California
late Tuesday that negatively tilts as it ejects northeast Wednesday
and early Thursday. While the synoptic forcing of this trough will
remain perhaps hundreds of miles south of the UP, the trough will
serve to make winds across the Mississippi Valley more southwesterly
instead of southerly, severing a potential Gulf moisture connection
that was initially expected to funnel high QPFs into the trailing
trough, which will itself eject out of the southern Rockies
Wednesday and arrive in the Upper Midwest early Thursday. The 06Z
deterministic GFS ended up near the high end of its own ensemble
regarding snowfall totals for KSAW, undermining the confidence of
high totals that are shown in the NBM 4.1 probs. The European and
Canadian ensembles lack the high ceiling of the GFS ensembles, but
holds a good floor of at least advisory criteria snowfall for
Thursday. Despite the ensemble disagreement, the ensembles generally
agree on a broad 1030s high filling the wake of the low, ending
precip for the UP early Friday.
Models diverge into near-chaos into the weekend, though the
ensembles (especially the Euro) favor another clipper of some flavor
over the weekend. Expect impacts relatively similar to the early-
week snow for the weekend if this verifies. Into next week, the same
pattern of troughing upstream supporting many shortwaves and below
average temperatures to persist. Winter is not dead!
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 532 PM EST SAT FEB 18 2023
VFR conditions are expected through tonight. Lowering ceilings are
expected ahead of an approaching clipper, with all sites expected to
be MVFR by Sunday morning. SAW could briefly go IFR Sun morning.
&&
.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 247 PM EST SAT FEB 18 2023
Winds across the lake are below 20 knots until early Sunday morning,
when southerly gusts increase to 20 to 25 knots in the east half. As
a cold front passes across Lake Superior Sunday, gusts across the
lake increase to 20 to 25 knots with the central lake seeing some
gusts up to 30 knots Sunday evening. Winds gradually decrease
overnight, and by Monday morning, winds across the lake are below 20
knots. Monday evening, southeasterly winds in the west half increase
to 20 knots ahead of a low pressure passing directly over the lake
overnight into Tuesday. This low will cause gale force gusts over
the central lake Tuesday morning and the eastern portions of the
lake by midday Tuesday. As the low departs Tuesday evening, winds
gradually fall below 20 knots overnight. With multiple shortwaves
passing over the CONUS Wednesday, tightening pressure gradient will
increase northeasterly winds to 25 to 30 knots Wednesday, with a
gale event expected Thursday. High pressure keeps wind below 20
knots on Friday.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
SHORT TERM...JTP
LONG TERM...GS
AVIATION...07
MARINE...GS
Area Forecast Discussion
National Weather Service Pueblo CO
314 PM MST Sat Feb 18 2023
.SHORT TERM...(This evening through Sunday)
Issued at 313 PM MST Sat Feb 18 2023
Key Messages:
1) Potential for strong/damaging winds srn I-25 corridor tonight
2) Windy and warmer on Sunday
Good deal of high level cloudiness has limited temps somewhat on the
eastern plains this afternoon, while better mixed areas near the
mountains have risen into the mid/upper 50s on the strength of gusty
west winds. Overnight, main concern is high wind potential over the
srn I-25 corridor, as mid/high level wly winds increase. Not a great
set-up for a strong mountain wave as shear profile is only briefly
neutral at best, though some gap-flow enhanced winds to 50 kts still
look possible from La Veta Pass eastward toward Aguilar and
Walsenburg through the night. HRRR gusts have been trending downward
the past few runs, so confidence in 60 mph gusts is somewhat low,
though with warning already out, will keep it in place for now.
Elsewhere, expect pockets of breezy west winds through the night,
keeping temps somewhat mild once again. A few snow showers will
reach the Continental Divide toward sunrise as upper wave
approaches, though better chances for snow will hold off until the
daytime hours on Sunday.
Winds increase area-wide on Sunday as upper wave drops through the
Rockies and mid/upper level jet remains over Colorado. Many areas
could see west winds gust in the 30 to 40 mph range by afternoon as
surface pressure falls on the plains and mixing deepens, with the
windiest spots in/near the eastern mountains. Max temps will climb
with the wind, and 40s/50s will be widespread, maybe a 60f reading
far southeast corner of the plains. Snow will become more widespread
along the Continental Divide through the day, though accums will
remain light with just an inch or 2 possible over the higher peaks
of the Sawatch/Mosquitos through the day.
.LONG TERM...(Sunday night through Saturday)
Issued at 313 PM MST Sat Feb 18 2023
Key Messages:
1) Potential for damaging winds near Rampart Range and northern
Sangre de Cristo Mountains Sunday night into Monday.
2) Heavy snow possible for eastern San Juan Mountains Tuesday
night into Wednesday.
3) Shallow arctic airmass for the plains possible Wednesday into
Thursday.
.Sunday night and Monday...Next trough passes to the east of the
region Sunday night. Behind the trough, northwest winds aloft will
move into the region. The atmosphere is setting up for the
potential for a mountain wave induce high wind event Sunday night
and into Monday. Subsidence will create a near mountain top
inversion with vertical shear being weak. The high resolution
models are picking up on the signal with a ribbon of higher winds
in the lee of the eastern mountains. The high resolution models
show an area of strong winds just to the lee of Pikes peaks with a
ribbon of winds,not quite as strong, extending northward into the
Rampart Range. Past experience with the high resolution models
suggest that the winds may be stronger in the lee of the Rampart
Range. Another area which can get strong winds are in the lee of
the northern Sangre de Cristo Mountains on the western edge of the
Wet Mountain Valley. Will maintain the high wind watch for this
time as would want to see another run or two to get the finer
details. Further south, high resolution models also suggest some
strong winds in the lee of the southern Sangre de Cristo Mountains
and southern slopes of the Spanish Peaks. Past experience
indicates that these areas do not get high winds with northwest
flow. In addition, the higher winds stay in the mountain zones
which have higher wind highlight criteria. Decided not to add them
to the watch at this time. Otherwise it will be a mild day with
windy conditions over and near the mountains.
.Tuesday through Thursday...Trough moves onshore over the Pacific
Northwest on Tuesday and moves into the Great Basin Wednesday
before lifting northeast across Colorado. Moist southwest flow
will impinge on the mountains Tuesday night and continues into
Wednesday night. The Continental Divide region looks to get
another round of significant snowfall with the heaviest snow over
the eastern San Juans. Very preliminary snowfall estimates are 1-2
feet for the eastern san Juans with around half the amount for
the remainder of the Continental Divide region. Further east, the
plains and eastern mountains will be near the southern boundary of
a shallow arctic airmass. Tricky temperature forecast for
Wednesday and Thursday depending on how far south the arctic air
reaches. Did not adjust the NBM temperatures which keeps the core
of the colder air further north. With southwest winds aloft, the
deeper arctic air would tend to stay further north and increased
solar radiation may modify the airmass. However, arctic air has a
tendency to move further south than what the models anticipate.
.Friday and Saturday...Another trough will move across the region
during this period with the best orographics over the eastern San
Juan Mountains. Arctic air on the plains moves to the east with a
warming trend. --PGW--
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 313 PM MST Sat Feb 18 2023
VFR at all taf sites the next 24 hrs. At KALS, still a brief window
for gusty SW winds into this evening, then occasional moderate s-se
winds expected overnight. Should be enough mixing to limit
fog/stratus potential overnight. Gusty w-sw winds then likely after
18z Sun. At KCOS, winds will become n-nw this evening and overnight,
then strong w-nw winds develop after 18z Sun with gusts to 35 kts.
At KPUB, occasional periods of west winds gusting to 25 kts possible
this evening and overnight. Still some potential for strong west
winds during the day Sun, though model data hints at a weak eddy
near the airport which may lessen wind speeds somewhat, especially
in the morning.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
High Wind Watch from Sunday afternoon through Monday morning for
COZ072-073-081-082.
High Wind Warning until 10 AM MST Sunday for COZ087-088.
&&
$$
SHORT TERM...PETERSEN
LONG TERM...PGW
AVIATION...PETERSEN