Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 03/06/23
Area Forecast Discussion
National Weather Service Binghamton NY
728 PM EST Sun Mar 5 2023
.SYNOPSIS...
High pressure will build into the area overnight, but clouds
will persist. A clipper system will bring some accumulating snow
Monday Night into Tuesday, mainly across the Twin Tiers and
Poconos of northeast PA.
&&
.NEAR TERM /THROUGH MONDAY/...
7 PM Update...
Near term forecast remains nicely on track. Stratus clouds,
along with a few sprinkles and flurries continue to stream over
the region under the relatively cold northwest flow. CAMs
continue to show this flurry/sprinkle activity tapering off by
late evening, but the clouds hang on well into Monday morning.
There could be some partial sun breaks late morning or early
afternoon before more mid/high level clouds arrive from the
west. Still a good deal of uncertainty on where a snow band will
set up with the incoming clipper system Monday night...although
the latest HRRR and RAP do push some snow north into the Twin
Tiers and even parts of Central NY, along with all of NE PA. We
will continue to closely monitor trends with this system.
3 PM Forecast...
A few flurries and/or sprinkles, mainly around Otsego and
Delaware Counties, will exit the area early this evening.
Surface ridge will be moving in overnight, but with N to NW low
level flow persisting, low clouds will stay in place over most
areas tonight.
Attention shifts to Monday night`s clipper system for which the
forecast remains stubbornly uncertain. The basic set up is a
weak surface low over northern IL Monday morning will move into
western PA Monday evening, then slide ESE towards the Delmarva
Peninsula by Tuesday morning. Meanwhile, our surface ridge axis
will shift NE into northern NY and New England. This will keep
northerly low-level flow in place across NY, while southerly
flow attempts to nose in from the south. A WNW-ESE oriented low
level frontogenesis band looks to set up, bringing a band of
light precipitation to the Twin Tiers and Wyoming Valley.
Several models suggest a narrow band of locally heavier precip
will develop across the area. The NAM is the furthest north,
producing liquid QPF amounts of 0.50 to 0.65 inches from the
southern ends of the Finger Lakes into the Southern Tier and
Catskills through midday Tuesday. The GFS is more intense, but
further south, focused across the Scranton/W-B metro and the
Poconos. The ECMWF is much weaker and brings only light QPF of
0.05 to 0.20 inches to the area. Meanwhile, the 12Z HREF members
(aside from the FV3) target the Twin Tiers, and thread the
needle north of S/WB. Ensemble products are also all over the
place. The 12Z GFS ensembles for KBGM brings 24hr snowfall (10:1
ratio) ranging between 0.1 and 10 inches.
The "thread the needle" solution seems to be the best
compromise, with 2-4" amounts stretching from southern Steuben
County (NY) into the Poconos, and just north of Scranton. Warmer
temperatures and perhaps a bit of sleet in the southern Wyoming
Valley could diminish accumulation significantly in lower
elevations.
Trying to pin down the mesoscale band, is not really possible at
this time, but locally higher amounts will be possible. With the
drier air filtering in from the north, expect a sharp cutoff to
precipitation on the north side.
With the uncertainty, especially with the 12Z ECMWF still coming
in so far south, we held off on advisories for the time being.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
210 PM Forecast...
A strong and elongated ridge of high pressure centered over
central Canada will extend into the CWA Tuesday night. This will
bring NW flow and cooler temperatures to the region. 850mb temps
Tuesday night look to be around -13C, which will be cold enough
to kick off lake effect snow showers off Lake Ontario. Lake
effect showers could reach all the way into NEPA, given NNW flow
will allow for the chance of Finger Lakes streamers to develop.
Snow totals are expected to be very light, with up to an inch
expected across the Finger Lakes and trace amounts in the Twin
Tiers. NW flow will continue through Wednesday night, keeping
the chance for light lake effect snow showers and flurries
continuing through the period. NW flow and cloud cover will keep
temperatures cooler than normal for this time of year, with
highs in the upper 20s to low 30s for highs Tuesday and
Wednesday and lows in the upper teens to low 20s Tuesday night
and low to mid 20s on Wednesday night.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
210 PM Forecast...
The elongated axis of high pressure will build into the region
Thursday, disrupting flow and ending chances for lake effect
showers. Temps will still be cool Thursday as the Canadian
airmass hangs around with NE flow over the area. WAA returns as
the ridge slides eastward Thursday night into Friday. Temps
should climbing back to near normal with highs in the upper 30s
to mid 40s.
The next storm system will impact the region this weekend. Model
guidance solutions vary greatly with how the atmosphere will
develop. It does look like precipitation will Friday night
through Saturday, but how the precip develops and in what mode
is still in question. Current forecast used ensemble guidance
and capped PoPs at chance due to the uncertainty present. Given
the large spread of uncertainty, model guidance should vary
greatly over the next several runs but should come into better
focus by Wed.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
MVFR stratus clouds look to persist through at least 04-06z at
most taf sites; except ELM and AVP which will see intermittent
VFR CIGs. The lower MVFR/IFR clouds shift away from SYR and RME
late tonight or early Monday morning, as the flow turns
northerly and high pressure builds in. BGM/ITH and ELM look to
hold onto the MVFR/Fuel alternate CIGs the longest, until around
15-18z Monday. Then VFR cloud bases are expected areawide Monday
afternoon before any light rain or snow develop after 00z Tuesday.
North-Northwest winds 5 to 15 kts expected through the period.
Outlook...
Monday night and Tuesday...Restrictions likely as another
weather system brings snow. Worst conditions in the Southern
Tier of NY and NE PA.
Wednesday and Thursday...Restrictions possible with lake effect
snow showers; mainly Central NY sites.
Friday...Mainly VFR under high pressure.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...None.
NY...None.
&&
$$
SYNOPSIS...MJM/MPH
NEAR TERM...MJM/MPH
SHORT TERM...JTC
LONG TERM...JTC
AVIATION...MJM/MPH/TAC
Area Forecast Discussion
National Weather Service Cheyenne WY
517 PM MST Sun Mar 5 2023
.UPDATE...
Issued at 513 PM MST Sun Mar 5 2023
Allowed current Winter Weather Advisories to expire. Latest HRRR
guidance showing snow ending over the western mountains. Followed
its guidance and allowed the advisories to expire. Updates have
been sent.
&&
.SHORT TERM...(Late this afternoon through Tuesday night)
Issued at 300 PM MST Sun Mar 5 2023
A cold front extended from just east of Chadron and Scottsbluff to
Kimball. Winds shifted to the northwest and were gusting to 45 MPH.
The temperature at Cheyenne dropped 15 degrees (48 to 33). The HRRR
did a good job developing banded snow showers ahead of the front,
with a snow squall that impacted parts of I-25 and I-80 from Laramie
to just north and west of Cheyenne late this morning. Snow showers
will continue, mainly west of I-25 through late afternoon. The Winter
Weather Advisory for WY Zones 110, 112 and 114 remains in effect until
5 PM.
An active southwest flow aloft with embedded shortwaves beneath a
150kt 250mb jet will provide the large scale lift, with enhancement
from surface convergence along a stalled boundary bisecting the CWA
from northeast to southwest. Snow showers will be focused from the
mountains east and northeast through the high plains. The 18Z WPC
guidance QPF trended down slightly from 06Z, with 0.25 to 0.50 inch.
Snow accumulations over the 60-hour period will range from 4 to 8
inches for elevations above 8000 feet, and 1 to 3 inches below. Weaker
low level pressure/height gradients will preclude strong winds, but
it will be blustery at times. Due to the prolonged nature of the
snowfall, did not consider issuing a Winter Weather Advisory at this
time. Later shifts can reevaluate with new model data.
Temperatures will average 10 to 15 degrees below normal with daytime
highs in the 20s and 30s. Nighttime lows will range from the single
digits and lower teens west, to the mid teens to mid 20s east.
.LONG TERM...(Wednesday through Sunday)
Issued at 300 PM MST Sun Mar 5 2023
The main focus of the long term forecast remains the potential winter
storm on Wednesday through Friday. However, there have been significant
changes to model consensus over the last 24 hours that have reduced
the odds of a major storm. Current consensus now tilts towards a minor
to moderate impact event for portions of the area for Wednesday night
through Thursday, though model disparity remains that will be detailed
below.
On Wednesday, we expect to have a stalled frontal boundary remaining
over our area with continued southwest flow aloft. A surface high over
the Canadian prairie will lead to increasing MSLP headed to the northeast
of us, and thus low-level upslope flow along and east of the Laramie
Range. Expect this to keep cold temperatures and low clouds mostly
locked in through much of the week ahead. Looking aloft, an earlier
weak shortwave will be skirting away from our area, while another
approaches from the west. We should be able to have a lull sometime
Tuesday night or Wednesday, but kept low end PoPs for most of the area
through this break due to timing discrepancies.
This second approaching shortwave will likely be the most noteworthy
of the week, but models have backed off significantly over the last
24 hours. Yesterday, GEFS mean 500-mb height anomalies had an upper
level low associated with the main longwave trough moving directly
over the Four corners, which is a concerning pattern. However, the
GFS and GEFS have come much more in line with the ECMWF solution with
today`s model runs. Now, the most likely scenario involves the main,
stronger upper level low hanging back off the coast of the Pacific
Northwest, while a shallower, weaker open wave ejects out ahead of
it across our area. This scenario is a much faster with less favorable
dynamics across our area. The GFS still shows a period of modest
isentropic lift overrunning the stalled frontal boundary with low-
level upslope flow Wednesday night, leading to a period of widespread
light to moderate snow along and east of the Laramie range. Such a
scenario would lead to widespread QPF values around 0.5 to 0.75" for
much of the area along and east of the Laramie range. However, even
after its considerable drop over the last 24 hours, the deterministic
GFS remains on the high end of the ensemble spread. Considering KCYS,
about 1/10 of the ECE members and 1/3 of the GEFS members show 0.5"
or more QPF through early Friday. The ECE mean is now about 0.25"
and the GEFS mean is around 0.5" owing to greater consensus around
the shallower, more progressive trough solution. There are certainly
known under- dispersion issues with these major ensemble systems
though, so we can`t rule out a significant storm still occurring
just yet, though the odds have decreased considerably. Right now,
the most likely scenario involves widespread light to moderate snow
overspreading much of the area Wednesday night through Thursday,
leading to advisory criteria totals for much of the area, with
perhaps some warning level snow possible in favored upslope areas
such as the southern Laramie range and Pine Ridge. The low-end
scenario is well depicted by the deterministic ECMWF, showing little
to no accumulation for most of the area except areas near and north
of US20. The high end scenario, shown on a few GEFS members, shows
a stronger but still progressive upper level low bringing briefly
heavy snow and stronger winds, leading to more widespread warning
criteria snowfall and northwest winds on the backside causing some
blowing snow headaches. At this time, the official forecast reflects
the ensemble consensus described above.
Looking towards Friday through next weekend, we start to see some
significant spread in the ensemble forecast. The leftover upper level
low near the Pacific Northwest coast is the main culprit of this
uncertainty. Whereas some solutions have this low starting to track
eastward shortly after the first low described above, others keep
it hung up in this area for several days longer. Regardless, a period
of moist westerly flow aloft looks likely to resume by late Friday
into Saturday and bring mountain snowfall back into the picture after
a brief lull late Thursday and Friday. There is strong consensus on
temperatures remaining below average through Friday, but an increasing
proportion of ensemble members (particularly ECE) are breaking the
tight grip of the cold temperatures by the weekend and bringing near
normal temperatures back to the picture for Saturday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 423 PM MST Sun Mar 5 2023
VFR is expected at all terminals this evening. However, low CIGs
and VIS are anticipated at KCDR and KAIA near 12Z Monday
morning. This will bring IFR/MVFR to those terminals. Reduced
CIGs and VIS can also be expected at KLAR and KRWL on Monday as
-SHSN spreads across the area beginning after 12Z and moving
slowly to the east. MVFR and IFR is possible during this time for
the SE WY terminals. Additional terminals may see MVFR
conditions, but confidence is not high at this time for it being
included in the TAFs.
&&
.FIRE WEATHER...
Issued at 300 PM MST Sun Mar 5 2023
Fire weather concerns will be low this week as a cold and unsettled
weather pattern dominates the region. A series of low pressure systems
will produce periods of light to moderate snow and blustery conditions.
Minimum relative humidities will remain well above critical thresholds.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...None.
NE...None.
&&
$$
UPDATE...GCC
SHORT TERM...MAJ
LONG TERM...MN
AVIATION...BW
FIRE WEATHER...MAJ
AREA FORECAST DISCUSSION
National Weather Service Hastings NE
548 PM CST Sun Mar 5 2023
...AVIATION UPDATE...
.DISCUSSION...(This evening through Sunday)
Issued at 233 PM CST Sun Mar 5 2023
Key Messages:
* A cold front will bring mostly cloudy skies and cooler
temperatures to start the work week.
* Unsettled weather could begin as early as Tuesday night,
although the brunt of the next system is not expected until
Thursday.
* Models have trended weaker and further north with the mid-week
system, focusing snow to our north and bringing a mix of rain
and snow to the tri-cities area. Still plenty of time for
changes as this system is still nearly 4 days away - although
model agreement and trends do not look promising for much in the
way of snowfall at this time.
* Below normal temperatures are expected for the end of the week
and into next weekend, although with normals climbing rapidly
this time of year, bitterly cold weather is not anticipated.
A very nice afternoon is being observed across the local area today
with afternoon temperatures 15 to 20 degrees above seasonal norms
and generally light southerly winds. The main exception is across
north central Kansas where these above normal temperatures are
being accompanied by occasionally gusty southerly winds...which
is resulting in elevated to near critical fire weather concerns in
a few spots. That said...expect winds to continue to diminish
through the remainder of the afternoon...helping to alleviate the
fire concerns.
For tonight...expect a cold front to our northwest to push south
across the local area by daybreak...with breezy northerly winds
and cooler temperatures in its wake. This cold front is helping to
fire up a couple of thunderstorms across the Nebraska panhandle
this afternoon...but is not expected to bring any precipitation
locally.
While temperatures will be noticably cooler behind this cold front
on Monday, they will remain seasonable...with most locations
reaching the 40s and lower 50s by afternoon. In addition to the
winds and cooler temperatures...expect a fair amount of cloud
cover through the day, with low level stratus expected to invade
the local area before daybreak Monday...eventually thinning out
later in the day. The HRRR seems to be the outlier for
tomorrow...with dense fog depicted covering much of the local area
by daybreak...and discounted this idea mainly due to steady and
breezy north winds as well as significant cloud cover advecting in
overnight...although a very narrow band of denser fog cannot be
completely ruled out on the leading edge of the incoming stratus.
For the remainder of the period...expect west southwesterly flow
aloft to continue across the region...with a quick passing upper
disturbance in this flow bringing a small chance for precip
Tuesday night into Wednesday...with little to no accumulation
expected. The better chance for precipitation will come with a
deeper upper level trough Thursday/Thursday night.
Originally...models were further south with this system...and
intensifying it as it crossed the area...but have since trended
further north with the 500mb circulation not being intensified
until it passes well east of the area. Given the trends...this
does not look overly promising for a significant precipitation
event across the local area...with the best chance of any
rain or snow now mainly across our Nebraska counties...with the
higher snowfall accumulations focused across the Dakotas. Will
continue to monitor as further changes are possible...but the main
impact at this time appears to be below normal temperatures
returning for the end of the week and into next weekend...although
again...bitterly cold air is not expected.
&&
.AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Tuesday)
Issued at 531 PM CST Sun Mar 5 2023
Skies have cleared out today and mostly clear skies will persist
through the evening hours. Late tonight, there is a chance for low
stratus and fog to return from the north...introduced some MVFR to
IFR conditions shortly after midnight...perhaps increasing in
coverage around daybreak. The real question is whether this is
limited to low stratus or if some denser fog develops...there is
model guidance supporting both. If this remains low stratus,
visibility will remain around 4SM to 5SM in areas of patchy fog...if
more widespread fog develops, visibility may drop as low as 1SM
or less for a brief period. Elected to go with 3SM to 5SM
visibility as more forecast soundings favor that solution and
breezy winds should hinder development of denser fog. Either way,
visibility will improve after sunrise and ceilings will gradually
lift during the morning...VFR conditions are expected from late
morning through the end of the TAF period.
Winds will be light and variable through around midnight, at which
time winds will begin to increase from the north. Winds will
continue to increase Monday morning to around 15 kts
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
DISCUSSION...Rossi
AVIATION...Hickford
Area Forecast Discussion
National Weather Service Goodland KS
516 PM MST Sun Mar 5 2023
.UPDATE...
Issued at 515 PM MST Sun Mar 5 2023
Allowed Red Flag warning to expire due to winds becoming light.
UPDATE Issued at 236 PM MST Sun Mar 5 2023
Red Flag Warning for Sherman and Thomas County has been cancelled
as winds and relative humidity values have remained well below
critical levels. Short term guidance indicates that this trend of
below critical criteria winds and humidity will continue through
the remainder of the diurnal mixing period, therefore minimizing
any threat for the rapid growth and spread of fires if one were to
develop. The Red Flag Warning for Cheyenne (CO), Greeley, Wichita,
Gove and Logan counties continues through 00Z.
&&
.SHORT TERM...(This evening through Wednesday Morning)
Issued at 120 PM MST Sun Mar 5 2023
A surface low is moving across the area with an associated lee
trough ejecting off of the Rockies. Warm front has lifted north
across the majority of the area along with locations south of I-70
behind a dryline located roughly from Smith Center to Great Bend.
Very dry air represented by large dew point depressions is being
observed behind the dryline as Scott City is 69/13 and La Junta is
65/1. Breezy to gusty winds are expected to increase through the
remainder of the afternoon as mixing increases and the low level
wind field strengthens. Based on 1 hour GFS/HRRR guidance it
appears that the most likely areas to see multiple hours of
critical fire weather will be located south of I-70 with locations
along the Interstate seeing perhaps an hour or two during the
late afternoon hours. Blowing dust threat continues to diminish
and will be removing from the forecast. Overall the Red Flag
Warning will remain through the rest of the afternoon.
This evening, a cold front moves through the area as winds will
switch to the NW. Winds will remain sustained around 10-15 mph as
low temperatures into Monday morning will fall into the lower 20s
over Yuma County to around freezing over the eastern areas.
Monday looks to be a relatively quiet and cooler day with high
temperatures in the low 40s to low 50s across the area. Into the
evening, winds will become easterly allowing for an upslope
component to materialize, a weak shortwave comes off of the
mountains leading to the potential for light snow and perhaps
light freezing drizzle along and west of the KS/CO border. I have
added in the light freezing drizzle for this package as forecast
soundings from the GFS/HRRR/NAM all show dry mid-levels with a
saturated low level. A warm nose is seen around 750mb, especially
south of I-70 across Cheyenne County Colorado and Kit Carson
county; north across Yuma guidance differs on if the entire column
will be below freezing or exhibit the warm nose so went with a
broad -ZL/-SN. It will also be worth monitoring how warm the
ground is for any slick spots to develop as temperatures have been
warmer and soil temperatures are a few degrees above freezing.
Nevertheless be prepared for slick spots if driving across east
Colorado Monday night into Tuesday morning especially across
bridges and overpasses.
Tuesday, will be by far the coolest day of the short term period as
all guidance has 850mb temperatures around 0C or less along with
mostly cloudy to overcast skies through the day. I did lower high
temperatures a few degrees from the NBM using a blend of
CONSRAW/MET guidance. As a result many locations will look to
struggle to get above the freezing mark Another chance of light
snow is possible across NW areas Tuesday night into Wednesday
.LONG TERM...(Wednesday through Sunday)
Issued at 105 PM MST Sun Mar 5 2023
Wednesday...the forecast area is under southwest flow aloft ahead of
an open and approaching upper level trough. During the day, moisture
in the 850-700mb layer slowly increases (mainly along and north of I-
70) with a dry slot above 700mb across the entire area. Presently
there is a slight chance for some light rain and/or snow along/north
of I-70. High temperatures are forecast to range from the middle 30s
to middle 40s. Overnight, the 850-700mb layer continues to saturate
under northeast to easterly surface winds at speeds of 10 to 15 mph.
The GFS/ECMWF models bring some mid level moisture across the
northern half of the forecast area as the upper trough approaches.
850mb temperatures hover around 0C with low temperatures in the
middle 20s to lower 30s. Will maintain chance to categorical pops
for rain/rain and snow/snow depending on location. Snowfall amounts
this cycle only a few tenths of an inch.
Thursday...GFS/ECMWF/GEM/GEFS models swing the upper trough axis
across the area during the day then into Iowa during the night.
There is quite a bit of dry air moving through the area while the
lower levels remain saturated enough to support some light
precipitation. With 850mb temperatures warming from south to
north during the day the current forecast highs range from the
middle 30s to around 40 along the KS/NE border to the upper 40s
across Tribune and Leoti. The warmer temperatures and a lack of
mid level moisture support have lowered overall snowfall amounts
quite a bit with amounts ranging from zero to one half inch
possible, highest across the north where cooler/colder
temperatures reside longer.
Based on the GFS/ECMWF/GEM 850-500mb relative humidity forecasts and
their qpf, its doubtful at this time to get any precipitation during
the night but for now will stay with the NBM`s slight chance to
chance pops for now. Low temperatures are forecast to be in the
lower teens to middle 20s.
Friday...the GFS/ECMWF/GEFS models show near zonal flow across the
area. Its currently forecast to be dry under increasing mid and high
level cloudiness. High temperatures are forecast to be in the middle
30s to lower 40s with overnight lows in the upper teens to lower
20s.
Saturday...GFS/ECMWF/GEFS 500mb flow shows a general westerly
component. 850-500mb relative humidity is quite high from the GFS
when compared to the ECMWF and shows a wave moving through the upper
flow during the night, supporting the NBM output of slight chance
pops for light rain changing to light snow. There is a large
discrepancy in 850mb temperatures during the day with GLD for
example showing -3C from the GEM, +4C from the GFS and +15C from the
ECMWF. No confidence to stray from NBM output highs in the lower to
upper 40s across the area. Low temperatures are forecast to be in
the lower to middle 20s.
Sunday...the current forecast has a slight chance for some light
rain for a few locations along/north of I-70 in the afternoon with
high temperatures in the middle 40s to around 50. This could be
supported by the GFS which has a weak wave moving through nearly
zonal flow aloft and some moisture in the 700-500mb layer moving in
from the west. Confidence however is low as the 500mb flow from the
ECMWF is similar to the GEFS and is drier throughout the atmosphere
compared to the GFS.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 246 PM MST Sun Mar 5 2023
VFR conditions are currently forecasted to persist through this
TAF period. Winds will become northwesterly as a cold front moves
through the area this evening. Some Hi-Res guidance such as the
GLAMP, HRRR have started picking up on a signal for some fog
potential Monday morning along and east of Highway 25, which may
impact KMCK. I am currently a little skeptical of this as winds
look to remain around 10 knots, which typically doesn`t support
fog formation. This will continue to be montiored through the
evening. Winds will become more ENE throughout the day Monday
around 10-12 knots.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JTL
SHORT TERM...Trigg
LONG TERM...99
AVIATION...Trigg
Area Forecast Discussion
National Weather Service Grand Rapids MI
1032 PM EST Sun Mar 5 2023
LATEST UPDATE...
Update
.UPDATE...
Issued at 1032 PM EST Sun Mar 5 2023
A mid level shortwave working east from the plains states towards
the Great Lakes is driving strong isentropic lift upstream this
evening, best seen on the 295K surface. Upglide is strong on the
order of 40-50 knots directly up the surfaces which has led to a
significant expansion in precipitation areal extent and intensity
over Iowa, Wisconsin and Northern Illinois. The zone of
upglide/lift works east into Lower Michigan in the next few hours
and continues overnight. The precipitation is occurring from
elevated bases between 850mb and 700mb. This is seen in cloud
bases of 6,000 to 8,000 feet upstream. The HRRR brings some weak
instability into the area tonight on the order of 200-400 j/kg at
max. Plenty of lightning occurring upstream as well as a few
reports of small hail. We will likely see some lightning sneak
into the area late, but not expecting any convection that results
in anything too serious.
Precipitation type should mainly be rain across the southwest
portion of the forecast area (south and west of GRR) with a mix of
rain/snow or snow elsewhere. Given the convective nature of the
precipitation we will see some snowfall rates overnight across
Central Lower Michigan that will at least reach moderate levels.
1-3 inches of snow is certainly possible by daybreak up there with
some impacts to morning travel. Best chance for accumulations that
will reach impactful levels are in the zone where we have a Winter
Weather Advisory out and will continue that headline as is.
&&
.DISCUSSION...(This evening through next Sunday)
Issued at 209 PM EST Sun Mar 5 2023
- Accumulating snow during the Monday morning commute for Big
Rapids, Mt Pleasant and Clare
We will issue a winter weather advisory for that region.
Difficult forecast for snow amounts and/or potential for a period
of freezing rain for the Monday morning commute. The area of
developing precipitation in northern IA and eastern SD is forecast
to track into Lower MI later tonight and through the CWA Monday
morning. Driving this precipitation is a 40 to 50 LLJ occuring
underneath a mid level wave that features some FGEN. Theta E was
decreasing with height in this area of precipitation in the
700/500 mb layer. That decrease in Theta E with height is forecast
to increase over the next couple of hours as the LLJ strengthens.
This setup does not change much as the system moves into our CWA
late tonight. Like many of the models are showing...the
precipitation should continue to expand as it moves into southwest
Lower MI and it could be convective. It`s unclear what the
surface temperatures will be like when the precipitation moves
in...mainly due to the convective potential of this system. Higher
precipitation rates will drive down the surface
temperatures...while lighter rates may allow them to stay a few
degrees above freezing limiting the impacts. Confidence on the
surface temperatures nearing freezing temperatures is highest near
and north of a White Cloud to Mount Pleasant line which is where
we will feature a winter weather advisory. Ensemble mean 24 hr
snowfall for Mt Pleasant from the GFS...Canadian and ECMWF support
a 2 to 5 inch snowfall for that region. It`s worth noting at
several high res models including the NAM an RAP are further south
with the accumulating snow and would suggest drawing that
advisory further south. Our confidence on this happening is not
high enough to feature a headline for places like Grand Rapids or
Lansing but it is something that will need to be
monitored/considered on later shifts depending on the trends. As
for the freezing rain potential...given the idea of heavier bursts
of precipitation due to the convective nature of this system...we
will limit the freezing rain risk. If it does happen...it should
be of a short duration.
- Impacts possible from the storm system for the end of next week
For several runs in a row the models have been showing a low
pressure system tracking through the southern Great Lakes region.
The forecast area is shown to be in the baroclinic zone. Stronger
mid level height fall are seen as well. Also, a negative tilt to
the wave in the upper levels is noted so upper level diffluence
should be supportive of widespread precipitation. The northern
zones stand the best chance to stay on the wintry side of the
storm where southern zones may swap over to rain. As usual this
far out...timing...track and strength differences exist. Ensemble
trends in GFS with the 24 hour snowfall have been increasing with
this system. We will feature above normal POPs for this end of the
week system.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 729 PM EST Sun Mar 5 2023
Low pressure will move from Kansas this evening to Ohio by Monday
evening. Precipitation will spread into the area tonight and
continue on Monday as a warm front sets up to the south of the
state. The precipitation will mainly be in the form of rain at the
TAF sites, but there will be some snow that mixes in at the I96
TAF sites tonight. The most widespread and heaviest precipitation
will occur tonight and Monday morning between 06z and 15z.
In terms of aviation conditions ceilings will slowly lower
overnight with IFR conditions settling in. IFR will become
dominant during the afternoon hours of Monday.
Winds will be from the east at 10-20 knots much of the next 24
hours. The strongest winds will be overnight.
&&
.MARINE...
Issued at 209 PM EST Sun Mar 5 2023
The winds will increase considerably tonight as the wave of low
pressure moves in. This system will feature a 40 to 50 knot low
level jet. The surface flow will feature an offshore component
with this system. Commonly this supports slightly less wind than
over the open waters. While a few gusts to gale force are
possible in the nearshore waters...ensemble mean wind gusts from
the ECMWF and GFS keep the values under gale force. For that
reason we will hold onto the small craft advisory.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...Winter Weather Advisory from 3 AM to 6 PM EST Monday for
MIZ038>040-044>046.
LM...Small Craft Advisory until 10 AM EST Monday for LMZ844>849.
&&
$$
UPDATE...Duke
DISCUSSION...MJS
AVIATION...Duke
MARINE...MJS
Area Forecast Discussion
National Weather Service New Orleans LA
546 PM CST Sun Mar 5 2023
...New AVIATION...
.SHORT TERM...
(This evening through Tuesday)
Issued at 317 PM CST Sun Mar 5 2023
Warming trend is expected for the area as the surface high
pressure centered north of the area treks eastward and winds turn
to south to southeasterly. This warmth will be unseasonably warm
(again) but not expecting any record breaking values.
Meanwhile, ample moisture from the onshore flow will help bring
higher dew points. For tonight and into tomorrow morning, there is
some signal for fog, possibly dense, especially for coastal MS
and nearby St Tammany/Washington parishes. SREF probabilities,
CAM guidance as well as the timing for 100% RH is conducive for
fog but the problem is just how dense will it be. Right now,
feeling fair confidence on some light patchy fog, but much lower
on dense (1/4 sm) fog. Due to this low confidence, held off on a
dense fog advisory for now but it will need to be revisited again
later tonight.
There is a fairly small chance of rain (5-10%) Monday afternoon
into the evening due to the higher moisture values and some weak
warm advection. Confidence is not super high on this either, but
synoptic hour runs of the HRRR has shown some isolated showers, so
opted to add a small 10-15% PoPs during this time frame.
&&
.LONG TERM...
(Wednesday through Saturday)...
Issued at 317 PM CST Sun Mar 5 2023
The central Gulf coast will remain under the influence of a broad
and persistent 500mb ridge axis stretching across the entire Gulf
of Mexico on Wednesday and Thursday. This ridging will extend
down to the surface, and this will keep rain chances suppressed
and temperatures well above average both days due to strong deep
layer subsidence. Given the strength of the subsidence in place
and increasing solar insolation as we move deeper in
climatological Spring, temperatures will easily warm into the mid
to upper 80s both Wednesday and Thursday over interior areas of
the CWA. Closer to the coast, the cooler shelf waters will keep
highs in the upper 70s and lower 80s. Overall, the deterministic
NBM remains on the lower end of the ensemble spread, and have
maintained using NBM 50th percentile values for the temperature
forecast on Wednesday and Thursday. At the same time, a persistent
onshore flow in the low levels, will increase low level humidity,
and a very muggy late Spring and early Summer like feel to the
air can be expected. The potential for some advection fog to
impact the area will continue to exist on Wednesday morning, but
the risk appears to be lower for Thursday morning due to an
increase in boundary layer winds. However, overcast skies from a
stratus deck will be in place during the early morning hours on
Thursday in response to the warmer air moving over the cooler
shelf waters. Any stratus will quickly clear by mid-morning as
temperatures warm and boundary layer mixing increases.
Heading into Friday, all of the deterministic guidance has come into
better agreement today. A progressive positively tilted trough axis
will eject out of the Four Corners Thursday night and pass through
the Plains and Midwest Friday into Friday night. As the trough
passes by, a cold front will slide into the area from the northwest
on Friday. Increased forcing along the front should produce clouds
and showers with the highest rain chances Friday afternoon
immediately ahead of the frontal boundary. Based on the lack of
strong deep layer forcing and limited instability as noted in model
soundings, have opted to stick with a chance POP forecast of 40 to
50 percent for Friday afternoon. There may be an isolated weak
thunderstorm that forms along the front, but weak mid-level lapse
rates should prohibit any deep and long-sustained convection from
forming. Temperatures will remain above average ahead of the front
with highs in the upper 70s and lower 80s expected.
After the front passes through the area Friday night, winds will
shift to the west and northwest, and a drier and cooler airmass will
begin to advect into the region. Although a 925mb thermal trough
will passing through, temperatures of around 50 degrees at 925mb are
supportive of highs near 70 for Saturday afternoon. Overall, a very
pleasant day is anticipated due to the lower humidity, near normal
temps, and mostly sunny skies.
&&
.AVIATION...
(00Z TAFS)
Issued at 538 PM CST Sun Mar 5 2023
Model sounding and satellite trend analysis has strengthened
confidence that a widespread low stratus and fog IFR event will
occur at all of the terminals. This will be a mixed event with
radiation fog being the primary concern at MCB and BTR, and
advection fog closer to the coast at GPT, ASD, HDC, NEW, MSY, and
HUM. IFR and lower Fog and stratus development should initially
begin at the coastal terminals of GPT and HUM around 08z as a
region of deeper moisture residing just offshore this evening
begins to move inland on the back of a developing southerly flow.
The advection fog will then spread north and impact MSY, NEW,
HDC, and ASD by 10z. Further inland, clear skies and marginally
favorable boundary layer winds of around 15 knots will interact
with radiational cooling and a developing inversion to induce
radiational fog and low stratus development between 09z and 11z.
The fog and stratus impacts will be most pronounced from 11z to
15z when the boundary layer is expected to be fully decoupled.
After 15z, all of the terminals will see conditions gradually
improve as temperatures warm into the 70s and 80s. By 18z, VFR
conditions are expected at nearly all of the terminals due to the
warming increasing boundary layer mixing. Only GPT could remain in
MVFR status with some broken stratus at 1500 feet due to
continued warm air advection over the cooler shelf waters.
&&
.AVIATION...
(18Z TAFS)
Issued at 1144 AM CST Sun Mar 5 2023
VFR conditions will prevail for about half the forecast period
before the potential of MVFR or IFR conditions overnight tonight
into tomorrow morning due to fog/lower stratus deck settling in.
Generally light winds out of the east will turn to out of the
south tonight, beginning to pump moisture back into the area.
Biggest chances right now are particularly for terminals closer to
the coast and the MS sound (KGPT, KASD, KHDC). Other terminals
could have some light and patchy fog. Best timing for fog
potential would be approx 09z to 16z. -BL
&&
.MARINE...
Issued at 317 PM CST Sun Mar 5 2023
Quiet conditions are expected for all the marine areas for the
week. Winds currently are in transition to onshore flow as high
pressure moves eastward. This light onshore flow pattern will
remain through basically the whole week. -BL
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 52 80 63 81 / 0 10 0 10
BTR 58 84 68 85 / 0 10 0 10
ASD 59 83 66 84 / 0 10 0 10
MSY 63 82 68 82 / 0 10 0 0
GPT 59 78 67 79 / 0 10 0 0
PQL 56 81 65 83 / 0 10 0 0
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...None.
GM...None.
MS...None.
GM...None.
&&
$$
SHORT TERM...BL
LONG TERM....PG
AVIATION...PG
MARINE...BL
Area Forecast Discussion
National Weather Service Marquette MI
713 PM EST Sun Mar 5 2023
.SHORT TERM...(This evening through Tonight)
Issued at 227 PM EST SUN MAR 5 2023
Water vapor imagery and RAP analysis reveal a pair of upstream
shortwaves which will be impacting U.P weather later tonight into
Monday. One shortwave is over the eastern Dakotas and another is
over the northern Rockies. Ridging has yielded mostly sunny skies
today over Upper Mi with temperature readings already reaching into
the upper 30s to mid 40s across the area.
Tonight, the first shortwave from the eastern Dakotas moves in later
tonight spreading snow into Upper MI courtesy of isentropic ascent
associated with the wave. The ascent looks like it will be strongest
into s central Upper MI where stronger winds are noted crossing
perpendicular to tightly spaced isobars on the mid-level theta sfcs,
and that is where most of the model guidance places the higher qpf,
similar to what GFS/CMC/ECMWF ensembles have been showing for days.
GFS/CMC/ECMWF also have been showing gradual downward trends in qpf
with a less aggressive n and ne advance of pcpn tonight. With some
of the CAMs, particularly the RAP and HRRR, starting to trend in
that direction as well, will lean the pcpn fcst tonight toward the
global models which have been leading the way on this event. The 12Z
NAM remains the farther north outlier solution. Expect -sn to spread
out of WI into the Ironwood area in the late evening, then advance n
and e thru the night. The snow may struggle to reach the Keweenaw
and the far eastern fcst area by 12z Mon as antecedent dry air and
weaker ascent work to limit the advance of snow. Away from those
areas, expect snow accumulations of 1-3 inches by 12z Mon, greatest
across s central Upper MI and in particular across Menominee County.
Will continue the Winter Weather Advisory for the south central
counties late tonight into Monday and will keep Marquette County in
the advisory mainly for additional expected snowfall and potential
lake enhancement Monday into Monday evening off of Lake Superior in
a ene wind direction.
.LONG TERM...(Monday through Sunday)
Issued at 324 PM EST SUN MAR 5 2023
Overall, not much has changed since yesterday with the primary focus
continuing to be the wet snow event that ends Monday night. Tuesday-
Thursday still looks like a nice stretch of mostly sunny weather
with warm, sunny days and cool, clear nights. Potential still exists
for a longer-duration event late this week, but confidence remains
low. A general trend from above- to below-normal temperatures is
expected throughout the extended period, but expect the whole week
to average above normal for most. Overall near normal precip is
expected, but that will depend on what happens late this week.
Starting at 12z Monday, a ~1008 mb surface low will be positioned
near Kansas City, MO with a broad precipitation shield displaced
well to the north across portions of MN/WI/MI. 12z Global models
continue to be farther south than CAMs with the axis of heaviest
precip, but the 15z RAP trended toward global models. The 12z
NAM/HRRR were considered outliers for this forecast package, which
also suggests HREF guidance is questionable. For the 12-hour period
between 12z Monday and 00z Tuesday the general consensus is for less
than 0.20" of QPF for all but the central UP where easterly upslope
flow may locally squeeze out >0.3" of QPF. Most models show two
local maxima, 1) over Marquette County where enhancement off Lake
Superior is possible and 2) over Menominee and Delta Counties where
enhancement of Lake MI seems more likely. Even though I trimmed QPF
substantially, I`m still not confident that the totals forecast for
Marquette County will materialize. Since precip rates aren`t
expected to be heavy, marginal surface temperatures and relatively
strong March sun may limit travel impacts especially during the
afternoon at lower elevations. A few hundredths of additional QPF
are expected Monday night, but the greater hazard may be associated
with patchy ice from refreezing of wet roads/sidewalks.
Tuesday through Thursday looks like a stretch of superb weather with
warm, mostly sunny days and cool, mostly clear nights. Ensemble
median 850mb temps are generally in the -8C to -10C range, which may
be cool enough for lake effect clouds and flurries at times.
However, the very dry air mass suggests mostly sunny/clear skies
should prevail at most places. Slightly increased Tmax for Tue-Thu
into the and decreased Tmin for Tue and Wed nights. Diurnal temp
ranges around 30F seem possible across the interior with lows around
10F and highs around 40F.
By Thursday evening a low pressure should be developing across the
South-Central Plains that lifts northeast toward the Lower Great
Lakes on Friday. This is somewhat faster than yesterday`s model
solutions suggesting snow may begin Thursday night and transition to
lake effect by Friday night or Saturday morning. Overall, model-to-
model and run-to-run differences continue to be large and this
should continue until the early week system moves away. GFS/CMC and
associated ensemble solutions favor a longer duration event whereas
ECMWF/EPS solutions do not. There does appear to be good agreement
that the post-system air mass will be cold enough for pure lake
effect as 850 temps cool to around -15C.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 713 PM EST SUN MAR 5 2023
VFR conditions will prevail into tonight before deteriorating
tonight as the next disturbance spreads snow over Upper Michigan.
Initially, terminals will lower to MVFR and eventually IFR or worse
around daybreak. Meanwhile, easterly winds will become strong
tomorrow afternoon at IWD and CMX with sustained speeds in excess of
12 kts and gusts to 22 kts.
&&
.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 324 PM EST SUN MAR 5 2023
Ridging over the lake keeps wind gusts below 20 knots until around
midnight when easterly wind gusts increase to 20 to 25 knots, then
increasing to 35 knot gales across the far western lake Monday
morning. Elsewhere, gusts increase to between 20 and 30 knots on
Monday before diminishing below 20 knots late Monday night. Despite
generally high pressure over the lake, the gradient between lower
pressure to the south and a 1050mb high over central Canada will
keep wind gusts around 20 knots through the midweek. Wind gusts
increase Thursday evening and into the weekend as a low pressure
tracks into the Great Lakes region, but uncertainty in the low track
makes forecast details difficult. However, should the low pressure
track near Lake Superior, gales are possible for the late week and
early weekend. Waves of 8 to 11 feet are expected on Monday and are
possible for the late week and weekend period if the low pressure
tracks close enough.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
Winter Weather Advisory from 4 AM Monday to 1 AM EST Tuesday for
MIZ005.
Winter Weather Advisory from 1 AM EST /midnight CST/ to 7 PM EST
/6 PM CST/ Monday for MIZ010>013.
Lake Superior...
Gale Warning from 7 AM EST /6 AM CST/ to 7 PM EST /6 PM CST/
Monday for LSZ162.
Lake Michigan...
None.
&&
$$
SHORT TERM...Voss
LONG TERM...EK
AVIATION...TDUD
MARINE...EK
Area Forecast Discussion
National Weather Service Pueblo CO
711 PM MST Sun Mar 5 2023
.UPDATE...
Issued at 654 PM MST Sun Mar 5 2023
Winds are decreasing and humidity values are starting to
increase across much of the area, therefore, have allowed much of
the High Wind Warnings and Red Flag Warnings to expire. With that
said though, conditions remain favorable for strong winds
overnight across the Southern Sangre de Cristo Mountains,
Walsenburg Vicinity/Upper Huerfano River Basin Below 7500 Feet,
and western Las Animas County, where a High Wind Warning remains
in effect until 8 AM Monday morning. Also, while winds have
decreased and humidities increased, a Red Flag Warning remains in
effect for parts of Huerfano County from 11 AM to 6 PM Monday,
where winds will again become gusty and humidity values are
expected to drop to around 10 percent.
&&
.SHORT TERM...(This evening through Monday)
Issued at 225 PM MST Sun Mar 5 2023
...Very strong damaging winds and Red Flag conditions will remain in
place over portions of Southeast Colorado through the early
evening...
Key messages:
1) Very strong and damaging winds, with areas of blowing dust, will
still be possible over portions of the San Luis Valley and plains
through the evening. Stronger winds will remain longer into the
early morning hours over the southern I-25 corridor.
2) Severe crosswinds could make travel dangerous over portions of
the southern I-25 corridor for high profile vehicles through the
early evening hours.
3) Critical fire weather conditions over the plains and Palmer
Divide will continue into the early evening hours. Critical fire
weather conditions are expected again tomorrow afternoon for
Huerfano County, and spotty conditions over areas of western Las
Animas County and the San Luis Valley.
4) Lingering snow showers over the northern Sawatch Range will be
winding down later this evening. There could still be some blowing
snow until then.
Detailed discussion:
Currently and tonight...
A longwave trough upstream is forcing a weak perturbation trough
over the area with very strong winds aloft between the 700 to 500 mb
level of over 100 mph. The tightening of the surface pressure
gradient, combined with brute forcing has allowed for very strong
winds and areas of blowing dust to be present over many of the lower
elevations in southeast Colorado. Strongest winds are currently in
the Walsenburg area, with gap flow winds through La Veta Pass
further enhancing some of the stronger gusts. This aligns with what
a lot of the higher resolution guidance is showing. Given this,
severe crosswinds could make travel dangerous over portions of the
southern I-25 corridor for high profile vehicles through the early
evening hours. Some of the higher resolution models, such as the
NAMNest and HRRR have the strongest winds also begin just downwind
of the southern Sangres and this is sticking around until the early
morning hours tomorrow with reverse shear showing up in the cross
sections over these areas, alluding to the likely occurrence of
this. Extreme fire weather conditions currently across the plains
and Palmer Divide will end by the early evening hours as winds begin
to subside, and relative humidities recover after sunset.
A cold frontal boundary with relatively cooler air behind it will
move through during the late evening hours through early morning
hours tomorrow. HRRR has this moving through a little quicker than
some of the other high res models, between 8 and 9 PM over Kiowa
County. This will allow for winds to become northeasterly across the
plains Forecasting low temperatures has been a challenge along
locations of the southern I-25 corridor, given the uncertainty of
how far west the boundary will make it with the strong westerly
winds shooting through the gap. Therefore temperatures have not been
modified too much, but there is the possibility that some locations
near the Walsenburg area could see temperatures as much as 10
degrees warmer if the winds remain persistent out of the west
through sunrise. Otherwise, temperatures will cool off quite a bit
over a majority of the plains, getting down into the low to mid 20s
for most locations. In high country, the lows will drop into the
teens and low 20s for the higher mountain valleys and San Luis
Valley, which is relatively warmer due to mixing with the winds, and
some single digits for the higher elevations.
Tomorrow...
Longwave troughing will remain in place upstream with slight ridging
over the region. This will allow for winds to diminish a bit and dry
conditions to be predominant across all of southeast Colorado. Winds
are still going to be gusty, but not nearly as strong tomorrow.
There will be some areas along the southern I-25 corridor, mainly
Huerfano County, which will still experience stronger gusts with
lower relative humidity values during the afternoon. Therefore,
critical fire weather conditions will be likely over areas of
Huerfano County, and there could be some spotty areas in western Las
Animas County, as well as in the San Luis Valley. Highs tomorrow
will be cooler with easterly winds in place across most of the
plains, and back around the seasonal average for this time of year.
The San Luis Valley will still remain on the more mild side, due to
the downsloping westerly winds still in place. -Stewey
.LONG TERM...(Monday night through Sunday)
Issued at 225 PM MST Sun Mar 5 2023
Key Messages:
1. Cold front will waver north to south across southeast CO
resulting in a challenging temperature forecast through mid week.
2. Potential exist for freezing drizzle across El Paso county and
portions of the southeast plains Monday Night and Tuesday and
possibly again Tuesday night into Wednesday.
Persistent southwest flow over the area through mid week will bring
mild temperatures and breezy to windy conditions across the
mountains and valleys. Meanwhile, a cold front will be wavering
northwest to southeast each day across the plains resulting in a
challenging high temperature forecast depending on where the cold
front lays up. This cold front will surge westward Monday night
with shallow saturation occuring across the southeast plains towards
morning, bringing the potential for drizzle and freezing drizzle
along and east of a line from Air Force Academy to Canon City to
Springfield. Area of greatest concern for will be across El Paso
and eastern Fremont counties where east to southeast upslope flow
will maximize orographic lift on the south side of the Palmer
Divide and against the higher terrain in eastern Fremont county.
Less confidence exists farther south across the east slopes of the
Wet mountains where a non-zero risk of some light icing could
occur. For now think some minor ice accumulations will more likely
stay confined to El Paso county where elevated surfaces may
become cold enough for some light ice accumulation early Tuesday
morning. Have introduced some fog into the forecast as well. Will
need to monitor this area for the potential for slick spots,
particularly bridges and overpasses. For now, models are
suggesting a Trace to 0.01 on the high side of accumulations,
which would suggest only minor impacts to travel. Otherwise, high
temperatures show quite a bit of variability within the NBM and
guidance across the plains Tuesday. Leaned towards the colder side
of guidance, especially across El Paso county where low clouds
are likely to linger through most if not all of the day. Greatest
uncertainty exists at KSPD where guidance and NBM probs gives a
range of highs from from 35 to 65. Stuck with highs generally in
the 40s for now. Will have to watch the southern I-25 corridor
counties for a return of critical fire weather conditions Tuesday
afternoon, but suspect that the cold air will be stubborn to
erode and we won`t quite make the 3 hours duration for fire
weather highlights.
The cold front will make another push westward Tuesday night with
another round of drizzle and freezing drizzle possible Tuesday night
into Wednesday morning. NBM pops are not picking up on this
potential, and with some uncertainty as to how deep and cold the
saturated layer will be have left FZDZ out of the grids for now.
This will need to be reassessed as higher res models begin to
resolve these details. But signals are there for a repeat
performance of freezing drizzle which could extend down into the
southern I-25 corridor as well. High temperatures on Wednesday are
in jeopardy of being colder than the optimistic NBM suggests and
have shaded them down across the plains in some areas. With the
approach of the next upper trough into the Great Basin Wednesday
afternoon some light snow will develop along the Continental Divide
with some overrunning precipitation, rain and snow showers, across
the Pikes Peak region during the afternoon. This upper trough will
glance by to the north Wednesday night and Thursday bringing some
light precipitation to northern areas. With a more northerly track
to this system, precipitation chances for the plains will be not be
all that great, but there could some brief showers along the cold
Thursday afternoon and evening.
Generally zonal flow will bring another chance for mountain showers
into western areas Friday night into next weekend though there is
quite a bit of variability in the models and ensembles. The
operational GFS much more amplified with another trough coming in
for late weekend. EC and EPS show a zonal to even a weak ridging
pattern with GEFS also much less amplified the operational GFS and
leaning towards a drier solution. Will keep majority of the pops
confined to the Continental Divide for now. -KT
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 225 PM MST Sun Mar 5 2023
VFR conditions are expected to prevail for all TAF sites (KALS,
KCOS, and KPUB) throughout the forecast period. Winds will be
synoptically influenced at all terminals. They are currently very
strong and gusty out of the SW, especially at KALS and KPUB where
gusts could occasionally reach 45 kts, and BLDU will still be
possible until 02Z at KALS and 01Z at KPUB. If this does occur, it
could bring down VIS temporarily to IFR/LIFR criteria. Winds will
begin to diminish and shift more to the SSW at KALS and then back to
the SW again, becoming gusty after 15Z and through the remainder of
the forecast period. At KCOS and KPUB, they will also weaken and
come around to the NNE and NE, and eventually SE and SSE
respectively, and remain that way through the end of the forecast
period.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
High Wind Warning until 8 AM MST Monday for COZ074-075-087-088.
Red Flag Warning from 11 AM to 6 PM MST Monday for COZ229.
&&
$$
UPDATE...SIMCOE
SHORT TERM...STEWARD
LONG TERM...KT
AVIATION...STEWARD