Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 03/04/23
Area Forecast Discussion
National Weather Service Binghamton NY
1006 PM EST Fri Mar 3 2023
.SYNOPSIS...
A strong low pressure system will track into the Great Lakes
tonight bringing a round of mixed precipitation and snow. This
low pressure system slowly moves east of our region this weekend
with high pressure building in behind with dry weather expected Sunday
night and Monday.
&&
.NEAR TERM /THROUGH SATURDAY/...
1000 PM Update...
Only minor adjustments to the immediate near term forecast
tonight with this update. Main change was to bring more of a dry
slot into the western half of the forecast area over the next
few hours (until 2-3 AM) as radar and satellite trends show this
occurring now. Also brought the mixed precip (sleet, freezing
rain and valley rain) further north and faster with this update.
Have received several reports of thunder snow/sleet over the
past 2 hours from Steuben county, up to Cayuga, Onondaga and
Oneida counties which was along an axis of conditional
instability, noted by colder/higher cloud tops on the 10.35um IR
satellite imagery. Added in some isolated thunder into the
grids along and north of I-90 for the next hour or two. Snowfall
rates are likely 1 to 2 inches per hour in this band.
Will keep current winter headlines as is for now, with freezing
rain and sleet still being reported in higher elevation
locations of NE Pa.
700 PM Update...
Steady snow has overspread much of the region in the past 2
hours. Some rain mixed in at the start for the valleys as
expected, but fairly quickly changed over to snow as wet bulb
cooling took place. The snow will overspread the NY Thruway
corridor and Oneida county by 8-9 PM this evening. For our
southern areas, latest obs and KBGM 0.5 Correlation Coefficient
product is already showing sleet and/or rain mixing in across SW
steuben County, southern Bradford county, Wyoming, Luzerne and
Lackawanna counties as of 7 PM. Temperatures fell as forecast
into the upper 20s to mid-30s as the precip (snow) quickly
overspread the region.
Overall the near term forecast remains in good shape and is
nicely on track. Made some minor adjustments, mainly to weather
type grids over the next 6-12 hours based on the latest
CAMS...especially the HRRR as it seemed to be handling the
incoming transition from snow to mix to rain well. Current
forecast now shows sleet mixing in with the snow along and
southwest of a Penn Yan--Binghamton--Monticello line by 9-10 PM
this evening...with sleet reaching Syracuse and Utica by
midnight or 1 AM tonight. Far northern Oneida county may stay
mainly snow for this event; however even here a bit of sleet or
freezing rain can`t be ruled out overnight as the warm layer
aloft races north. For the Twin Tiers south across all of NE PA,
some rain could very well mix in (especially lower elevations)
starting this evening in NE PA and after midnight for CNY. As
the strong low over the Great Lakes starts to occlude and
transfer its energy to a developing coastal low along the
NJ/Long Island coast late tonight; some colder air aloft
gradually rotates back into the area from NW to SE. This looks
to change the rain back to wet snow toward daybreak Saturday for
the Twin Tiers (although valleys may see rain still). Further
north across the Catskills, NY Thruway corridor and northern
Oneida county any mixing should go back over to snow around
daybreak and continue into the day Saturday as the 700mb low
circulation develops an area of light to moderate snow on the
western flank of the surface low. Overall only minor adjustments
to snow and ice amounts with this evening`s update.
300 PM Update...
Precipitation is making its way through PA and based off of
webcams and surface observations the precipitation is
transitioning to snow quickly with wetbulbing. Temperatures have
warmed across the region with many of the valley locations
wetbulb temperatures are over 33 degrees. Temperatures were
lowered as the precipitation moves in to force some snow into
the grids sooner so most valley locations outside of the Finger
Lakes will only have an hour of rain prior to snow changeover.
Downsloping in the lower elevations of the Finger Lakes will
help keep temperatures warmer longer after precip onset. A
strong 700 to 500 mb frontogenesis band moves through so once
the precip transitions to snow it will be heavy, with rates
approaching 1 inch per hour, mainly north of the NY/PA border.
Southerly winds at 700 mb at near 70 knots will advect in
temperatures above freezing aloft so precipitation will be
changing to sleet from south to north. The depth of the cold air
below the melting layer is still looking deep enough that
refreezing of the rain is likely so any freezing rain is limited
to high elevations.
Snow accumulations were lowered slightly in the Southern Tier
and southward as forecast soundings show that transition to
sleet happening in the early evening not long after sunset so
there is a short window for snow accumulations. Strong SE flow
will also lead to some downslope warming in the Wyoming Valley
so there may not be much if any snow accumulations there. Higher
elevations of NEPA still look to see a quick inch or so before
the transition to sleet and eventually rain tonight. Further
north along the Thruway, the SE flow will also lead to some
downsloping into the Syracuse area so snow totals were lowered.
Oneida county holds onto snow the longest and with the snowfall
rates approaching 1.5 and possibly 2 inches per hour near the
Tug Hill will help pile up the snow before the changeover around
midnight. There is still the concern that the warm front does
not slow as it moves north if the coastal low is any slower at
developing and the changeover happens sooner than forecast
north of the Thruway.
Once the coastal low develops late tonight into tomorrow
morning, subsidence begins over our region with stratiform
precipitation becoming more showery in nature. Some wrap around
snow showers will persist across CNY and the Finger Lakes into
tomorrow evening. Accumulations will be limited to higher
elevations as the light QPF and higher sun angle with breaks of
sun between clouds will melt snow faster than it can accumulate.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
230 PM update...
NW flow aloft, and a weak shortwave trough grazing by northern
NY will keep a few snow showers around Saturday night into early
Sunday, mainly over areas east of I-81. Surface high pressure
will shift east into central NY and central PA by Monday
morning, with precip from the next system likely staying at bay
until Monday night.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
230 PM update...
Surface low pressure over the Midwest will quickly track east
across Lake Erie by Monday evening, tracking south of the NY/PA
line and emerging SE of Cape Cod by Tuesday afternoon. Warm
advection ahead of this system will lead to a band of
precipitation developing across central NY Monday evening, and
spreading across the Twin Tiers Monday night.
There will be a risk of more mixed precipitation with this
system, though the warm nose is less pronounced than with the
current (Fri Night/Sat) system. The GFS tries to keep mostly
snow near and north of the Southern Tier of NY, but is often
biased with not pulling warm air far enough north. NBM-based
p-type grids actually look pretty good, keeping the risk of
mixed precip as far north as the Thruway Monday night into
Tuesday. Still too early for snow/ice accumulations, but liquid
QPF ranging from ~0.35 to 0.75 inches would suggest travel
impacts are likely, mainly from the Twin Tiers northward, with
rain more likely further to the south.
A prolonged period of NW flow and seasonably cool temperatures
looks to settle in behind this system, with light lake effect
snow periodically enhanced by weaker embedded shortwave troughs.
Low level winds are sub-optimal for a multi-lake connection,
with 850mb temps only in the -8 to -10 range except for when a
couple of shortwave troughs drop through. Most days will have
plenty of lake effect clouds and flurries/sprinkles, with highs
in the lower to middle-30s (except lower 40s Wyoming Valley PA),
and lows in the 20s.
&&
.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
715 PM Update
Snow and mixed precipitation is now overspreading the entire
forecast area, and will reach RME by 01-02z this evening. IFR to
LIFR restrictions are being observed in the snow as it moves in.
LLWS will be present at all terminals until around 12z Saturday
as a strong low level jet moves in with the warmer air.
AVP: Precipitation is already changing over to rain, but some
sleet or snow could still mix in through about 03z this evening.
The downsloping easterly flow off the Poconos is causing CIGs to
remain higher here, low end VFR for MVFR through the overnight
period. As the wind shifts Saturday morning to west-northwest
some borderline IFR/MVFR Fuel alternate CIGs are expected along
with scattered rain showers here. CIGs should rise back to
higher end MVFR by Saturday afternoon with mainly dry
conditions. East-southwest surface winds gust up to 30 kts
overnight.
BGM, ITH, ELM: IFR to LIFR snow has moved in on schedule and
last until about 02Z to 04Z when warm air moves in overhead and
(sleet) ice pellets mix in which will help improve the vis to
MVFR at times. Precip changes back to a mix of snow and valley
rain late tonight into Saturday morning with low end MVFR to
IFR cigs through the day.
SYR, RME: Snow moves in around 00-02Z and will be heavy with
LIFR vis most likely at times through around 6Z. Snow mixes with
sleet and helps improve vis somewhat. Once a cold front moves
through late tonight precip changes back to all snow with MVFR
vis and cigs lasting through much of the day on Saturday.
Outlook...
Saturday night through Sunday...Lingering cold northwest flow
will allow for MVFR to IFR CIGs with a few snow flurries or
showers possible at times off the lakes or with a weak clipper
system Sunday afternoon.
Sunday night and Monday..Improving to VFR likely.
Monday night and Tuesday...Restrictions possible as another
weather system brings a mix of snow and rain to the area.
Wednesday: Restrictions possible with lake effect snow showers;
mainly Central NY sites.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...Winter Weather Advisory until 1 PM EST Saturday for PAZ038>040-
043-044-047-048-072.
NY...Winter Storm Warning until 1 PM EST Saturday for NYZ009-037-
046.
Winter Weather Advisory until 1 PM EST Saturday for NYZ015>018-
022>025-036-044-045-055>057-062.
&&
$$
SYNOPSIS...AJG/MJM
NEAR TERM...AJG/MJM
SHORT TERM...MPH
LONG TERM...MPH
AVIATION...AJG/MJM
Area Forecast Discussion...Updated
National Weather Service Billings MT
819 PM MST Fri Mar 3 2023
.UPDATE...
Extended the higher PoPs for S. Big Horn, Sheridan County and SW
mountains out until 06Z, after which time the HRRR shows
precipitation ending as the airmass dries out. Also kept some low
PoPs from KLVM to KBIL to Rosebud County and N based on light
radar returns. Arthur
&&
.DISCUSSION...
Tonight through Saturday Night...
Some lingering snow showers in the mountains and foothills will
persist into the early evening following a Pacific Cold Front that
moved through today. Outside the mountains the rest of the area
will remain dry overnight as the flow continues to become more
zonal to flat ridging overnight.
Winds will decrease across the over the lower elevations this
evening, but the foothills will continue to see elevated gusts to
around 30 mph through the early morning hours Saturday. Flow aloft
will start to turn more southwesterly tomorrow ahead of the
trough over the Pacific Northwest that will be our weather maker
next week. With the downslope flow, temperatures will remain
around normal with highs in the 40s Saturday. Through the evening
Saturday night, the southwesterly flow will bring increasing
chances to the southwestern mountains. Reimer
Sunday through Friday...
The extended forecast will be dominated by an upper trough over
the western US early in the week, then weather pattern uncertainty
late in the week.
Sunday into Monday, the large-scale upper trough axis will be
located along the West Coast, with several shortwave troughs
moving northeastward over the Northern Rockies. These shortwave
troughs will bring areas of ascent over the region and produce
periods of snow. At the same time, surface high pressure over
Canada will supply colder air to the region. The temperature
forecast suggests that snow accumulation will be limited to
grassy surfaces during the daytime but will occur on most-all
surfaces at night when air temperatures are lower and there is no
solar heating. Precipitation amounts look light, around 0.10-0.30
inches. Snowfall amounts could reach about 1-3 inches on grassy
surfaces Sunday, then 1 inch or less on all surfaces Sunday night,
then another 1 inch or less on grassy surfaces again Monday. In
terms of probabilistic snowfall, NBM shows the chance of receiving
at least 2 inches of snow on grassy surfaces from Sunday through
Monday is 50-90% over much of south central MT and eastern Fallon
and northeastern Carter Counties and 20-50% over the valleys of
Park County, MT and much of southeast MT to the Sheridan County
Foothills.
Monday night into Friday, uncertainty increases as model solutions
diverge on how the upper air flow pattern will evolve. Some model
solutions bring additional precipitation over our region from
an upper low while others bring an upper ridge over the area and
produce mostly dry conditions. Models do generally agree that the
heavier precipitation should occur to the east of Billings with
lighter amounts west of Billings. Stay tuned to the forecast as we
refine the details for next week.
High temperatures will generally be in the 20s and 30s Sunday
through Friday, though the uncertainty does increase for
Wednesday-Friday. By Friday, the NBM shows the 10th-90th
percentile range in high temperatures at Billings to be 19F to
44F. RMS
&&
.AVIATION...
Expect scattered snow showers to continue over the lower
elevations central and west through 02z, and in the mountains and
foothills through 03-04z. West winds will gust 20-35 knots across
the lower elevations through around 01Z. Winds will stay elevated
along the western foothills (KLVM) tonight. Expect local/brief
MVFR to IFR with any snow showers in the mountains, as low as LIFR
in the foothills (KSHR), while mountains are frequently obscured.
Otherwise, VFR will prevail over the next 24 hours. Chambers
&&
.PRELIMINARY POINT TEMP/POPS...
Sat Sun Mon Tue Wed Thu Fri
-----------------------------------------------------------
BIL 021/040 025/033 021/030 017/032 017/030 017/031 011/033
20/B 27/S 65/S 32/S 22/S 32/S 22/S
LVM 015/035 022/030 017/027 013/032 013/029 011/031 011/034
21/B 48/S 54/S 31/B 11/B 21/B 23/S
HDN 013/040 020/033 017/030 011/032 012/031 012/030 006/033
20/U 16/S 64/S 43/S 33/S 43/S 32/S
MLS 017/038 023/032 016/027 017/027 013/026 013/027 007/026
00/U 15/S 33/S 33/S 22/S 23/S 22/S
4BQ 018/040 024/034 019/029 018/029 015/028 016/028 007/028
00/U 24/S 43/S 34/S 33/S 33/S 22/S
BHK 013/036 021/030 011/023 008/022 007/022 009/023 006/023
00/U 46/S 52/S 34/S 33/S 23/S 22/S
SHR 010/035 013/029 012/026 009/028 009/026 008/025 003/029
80/U 15/S 33/S 33/S 23/S 33/S 22/S
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...Winter Weather Advisory in effect until 11 PM MST this
evening FOR ZONES 138-169.
WY...Winter Weather Advisory in effect until 11 PM MST this
evening FOR ZONE 199.
&&
$$
weather.gov/billings
Area Forecast Discussion
National Weather Service Charleston SC
1036 PM EST Fri Mar 3 2023
.SYNOPSIS...
A cold front will move through tonight, followed by high
pressure through early next week. Another front will cross the
area on Tuesday night. High pressure will return for the middle
of next week.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
Southwest winds will continue strong in many areas into the
overnight as we tap into the low level jet where there are
winds as strong as 45-55 kt. In addition, with DCAPE in excess
of 700-800 J/kg there will be similar gusts with a band of
showers that still has several hours before it clears the
forecast counties. As a result we have extended the Wind
Advisory by 1-3 hours.
The aforementioned band of showers associated with the cold
front is still outside the forecast region as of this writing.
But it will finally move into our northwest tier by 12 AM,
reaching Charleston, Beaufort, Savannah and Hinesville around 2
to 3 AM, and off the coast before daybreak, except for parts of
coastal Georgia.
While there hasn`t been any lightning recently, since there is
still some CAPE, we held onto a slight chance of t-storms
through the night.
While we do have PoPs as high as 70-80 percent, it won`t rain
more than about an hour at any given location. This will keep
the QPF down under 1/4 inch.
We adjusted the hourly temps quite a bit warmer based on trends
and a slower arrival of the showers and cold front. This will
result in slightly higher min values than the previous
forecast, as once again it`ll end up being far above climo.
Previous discussion...
A record high temperature of 85 degrees was tied at KSAV today.
We felt compelled to expand the Wind Advisory to include a few
more counties, including inland Chatham, which includes the
Savannah area. This is based on soundings and most guidance
actually showing winds just as strong if not greater than in
some places where we already had a Wind Advisory. The 00Z
radiosonde launch from KCHS has revealed winds of 30 kt at 1000
ft, 45 knots at 2000 feet and 49 knots at 3000 feet. Suffice to
say that the Wind Advisory is a good call as it won`t take much
to tap into these winds.
Our updated forecast leaned heavily toward the HRRR and HREF
regarding the timing of the band of showers and perhaps a few
t-storms. This is around 11 PM to 1 AM as it crosses our
northwest tier, 1 AM to 3 AM for the Charleston, Beaufort,
Savannah and Hinesville regions, and off the coast by 5 AM to 6
AM. Within a moist southwest flow and a CAPE axis to move in,
some renegades showers can occur out ahead of the main
convective line. No changes in the thinking about how much
t-storm activity there will be if any, as we show isolated
coverage wherever we have 30% or greater chances of rain.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
The cold front will be just offshore by daybreak Saturday. A
cooler and drier airmass will dominate through Monday as large
high pressure extends across the Southeast U.S. and the polar
jet remains displaced well to the north. A weak coastal through
will begin to develop off the coast by late Sunday afternoon
into Monday in response to high pressure shifting off the North
Carolina Outer Banks. No meaningful impacts are expected from
this feature except maybe a slight uptick in marine-based
stratocumulus moving along parts of coastal Georgia in the
northeast low-level flow. Although it will be somewhat cooler,
temperatures will generally remain above normal for early March.
Highs Saturday will peak in the mid-upper 70s in the offshore
flow then cool to the lower-mid 70s Sunday with mid 70s to lower
80s Monday. Lows both Sunday and Monday mornings will bottom
out in the upper 40s well inland to the mid-upper 50s at the
beaches.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
A progressive, zonal flow will gradually give way to a strong
ridging pattern across the central and eastern CONUS through much of
the extended period. A cold front will drop through the area Tuesday
night and well well to the south, but with limited moisture return
ahead of it very little in the way of meaningful rainfall is
expected. A modified cP airmass will finally settle into the
Southeast U.S. by mid-late week which will usher in a return to
temperatures at or even below normal as Canadian high pressure
dominates. By Thursday, highs may struggle to warm out of the mid-
upper 60s. A stationary front to the south may return as a warm
front Friday, serving as a focus for scattered showers.
&&
.AVIATION /04Z SATURDAY THROUGH WEDNESDAY/...
VFR early tonight, before a band of showers and maybe a couple
of t-storms moves across the terminals between 06Z and 09Z.
When it does, MVFR visibilities are expected. There will be a
few showers out ahead of this main band, mainly at KSAV. We
include VCSH for this occurrence. VFR will return late tonight
and through Saturday.
S and SW winds will remain elevated until the convection moves
through, averaging around 20 kt sustained, with peak gusts of
near 30 kt, perhaps occasionally higher given winds as high as
40-50 kt around 2000-3000 feet. Winds veer W with the passage of
a cold front after the showers end, and speeds drop considerably
thereafter.
Extended Aviation Outlook: There are no concerns at this time.
&&
.MARINE...
Tonight: A tight gradient will exist in response to an
approaching cold front, which leads to Gale Warning for all
waters except the Georgia waters out 20 nm. 1000 mb geostrophic
winds of 50+ kt will persist through at least 06Z, and although
tempered somewhat by warm advection, we`re still looking at
frequent gusts of 35 to 45 kt over the marine zones where we
have the Gale Warning in effect. It`ll be close to Gales on the
AMZ354 waters, but it still appears that winds will stay just
short. We do maintain mention of the Hazardous Weather Outlook
just in case a short duration Gale Warning becomes necessary.
Mariners can expect a band of showers and maybe a few t-storms
to move in with the cold front by 1-3 AM, before they exit most
of the region, with the exception of the outer Georgia waters
by daybreak.
Saturday through Tuesday: Conditions will steadily drop below Small
Craft Advisory levels for seas Saturday morning as high pressure
builds into the area behind a cold front. Offshore winds will turn
northeast Saturday night into Sunday with somewhat of an enhanced
pressure gradient developing resulting in winds 15-20 kt. There
could be a few gusts to 25 kt over the waters, but these do not look
frequent enough to justify a Small Craft Advisory at this time.
Winds will gradually veer more southerly Monday into Tuesday ahead
of another cold front.
&&
.CLIMATE...
Record High Temperatures:
March 3:
KCHS: 86/1976
KCXM: 80/2022
KSAV: 85/2023 and previous
Record High Minimum Temperatures:
March 3:
KCHS: 64/1997
KCXM: 65/1997
KSAV: 65/1899
March 4:
KCHS: 63/2008
KCXM: 65/1917
KSAV: 65/2008
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...Wind Advisory until 1 AM EST Saturday for GAZ087-088-099>101-
114-115-118.
SC...Wind Advisory until 1 AM EST Saturday for SCZ040-042-043-047-
051.
Wind Advisory until 3 AM EST Saturday for SCZ044-045-048>050-
052.
MARINE...Gale Warning until 7 AM EST Saturday for AMZ330-350-352-374.
Small Craft Advisory until 7 AM EST Saturday for AMZ354.
&&
$$
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
CLIMATE...
Area Forecast Discussion
National Weather Service Cheyenne WY
442 PM MST Fri Mar 3 2023
.SHORT TERM...(Late this afternoon through Sunday night)
Issued at 235 PM MST Fri Mar 3 2023
Broad, low-amplitude upper level trough extends from the Intermountain
West through the northern/central Great Plains. Embedded within the
quasi-zonal flow aloft are several shortwave disturbances. One was
moving east through southern SD/northern NE, with another moving across
WY. These disturbances are providing sufficient lift with weak mid level
instability (~100 j/kg MUCAPE) enhancing snow shower development. A
couple bands of moderate to heavy snow were impacting travel along
I-80 between Rawlins and Laramie. The latest high-resolution guidance
continues to show potential snow squalls developing along the Pine
Ridge (Niobrara County WY to Dawes County NE) and Cheyenne Ridge
(I-80 Summit east to Kimball/Sidney NE) late this afternoon and early
evening. A quick one inch of snow is likely under these heavier snow
bands. Besides the snow showers, gusty westerly winds of 35-45 MPH
will produce blowing snow and visibility under a half mile at times.
The Snowy/Sierra Madre mountains can expect an additional 3-5 inches
through late this evening where a Winter Weather Advisory remains
in effect until 11 PM. The snow will end from west to east late
tonight. Total mountain accumulations will range from 4-8 inches above
8000 feet.
Saturday will be the transition day as a upper level ridge shifts west
to east over the CWA. Slightly elevated mid level heights/thicknesses
and southwesterly low level flow will allow for modest temperature
moderation with afternoon highs in the 30s and 40s. Clouds increase
from west to east Saturday afternoon in advance of the next Pacific
shortwave trough. Snow showers will develop and increase in coverage
west of the Laramie Range Saturday evening. The showers will spread
to the I-25 corridor Sunday. Scattered snow showers will continue
Sunday night over the southern WY mountains, with more isolated coverage
to the immediate east with the passage of a cold front. 850mb gradients
(CAG-BRX/CAG-CPR) increase to 50-60 meters by midday Sunday. 700mb
winds peak near 55kt along the Laramie Range Sunday morning. Random
forest high wind probabilities are 40 percent for Bordeaux with peak
gusts 50-55 MPH midday Sunday. East Platte County (I-25 Coleman)
probabilities are 55 percent with peak gusts just below 58 MPH. Therefore,
confidence for high winds is low to moderate. Low confidence for the
remaining wind-prone zones with probabilities around 20 percent.
Nonetheless, periods of moderate to heavy snow with blowing snow are
expected for the Snowies/Sierra Madres Saturday night through Sunday
afternoon. Total mountain accumulations of 6 to 11 inches are forecast
above 8000 feet. Winter Weather Advisory remains in effect from 8
PM Saturday through 5 PM MST Sunday afternoon. Sunday will be milder
east of the Laramie Range with gusty downslope winds and highs in the
40s to around 50.
.LONG TERM...(Monday through Friday)
Issued at 235 PM MST Fri Mar 3 2023
The long term forecast remains rather dreary with below average
temperatures and daily snow chances expected. Luckily, high wind
potential looks minimal next week due to the current flow pattern
aloft.
The first half of the work week will feature a near-zonal flow pattern
with a few embedded shortwaves. This will funnel fairly moist Pacific
air into the CWA. The position of the jet max over the CWA, in
conjunction with the shortwaves, will provide a sufficient lifting
mechanism in order to generate light snow with this moisture. Monday
through Wednesday, a few rounds of light snow can be expected across
the area. Although significant accumulations are not expected with
each wave, the compounding accumulation over several days could lead
to decent snowfall amounts. Across the plains, 2 to 5 inches of snow
between the Monday to Wednesday timeframe could be possible. These
amounts are also in agreement with both GEFS and ECMWF ensemble
guidance. For the end of the work week, deterministic models are
finally starting to align on a similar solution. Both the GFS and
ECMWF are showing a deep trough moving across the Rockies Thursday
through Friday. The GFS shows a deeper trough with the surface low
setting up further south in southern Colorado/northern New Mexico.
This would not be the most ideal set-up to get significant snowfall
amounts, but the GFS still has impressive QPF amounts over the two
days with a saturated profile due to a moisture stream out of the
Gulf of Mexico. The ECMWF also has the surface low set up around
the Colorado/New Mexico border, but without the moisture tap into
the Gulf to provide better QPF amounts. Of course, this storm still
sits out in Day 7 so models still have time to resolve this system.
Lastly, this pattern also keeps us colder than average for the week
with the frontal boundary hanging around in southern Colorado. Lowered
temperatures for the week below NBM guidance as 700 mb temperatures
will range from -12C to -16C. Highs next week will range from the
20s to lower 30s which puts temperatures about 10 to 20 degrees below
average. If the deep trough in Day 7 comes to fruition, even colder
temperatures can be expected.
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 438 PM MST Fri Mar 3 2023
Southeast Wyoming Terminals: Some lingering showers are possible
this evening, but the main precipitation line has moved off into
western Nebraska. Cannot rule out low CIGs and visibility drops that
may occur if -SN showers pass over any terminals. Behind the
precipitation line, winds will remain rather strong with gusts over
30 kts possible at times. Winds will likely ease later tonight with
clearing skies. Expect VFR conditions through the day Saturday.
Western Nebraska Terminals: VFR to MVFR conditions are expected
overnight tonight for the Nebraska terminals as a line of snow
showers moves across the area. Low ceilings and visibilities are
likely with the snow showers. The HRRR shows a line of snow
showers developing at 00Z Saturday. A line of snow showers has
formed just west of the Nebraska/Wyoming border and will begin to
impact Scottsbluff within the next hour. The other terminals will
likely see snow uptick over the next 2-3 hours.
&&
.FIRE WEATHER...
Issued at 235 PM MST Fri Mar 3 2023
Widespread snow cover from recent weather disturbances and additional
accumulating snow over the next several days will limit fire weather
concerns. Windy conditions with minimum humidities of 25 to 35 percent
are forecast east of the Laramie Range this weekend through Sunday.
The trend of below normal temperatures and above normal precipitation
will continue next week due to a persistent and active weather pattern.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...Winter Weather Advisory until 11 PM MST this evening for WYZ112-
114.
Winter Weather Advisory from 8 PM Saturday to 5 PM MST Sunday
for WYZ112-114.
NE...None.
&&
$$
SHORT TERM...MAJ
LONG TERM...SF
AVIATION...SF/AM
FIRE WEATHER...MAJ
AREA FORECAST DISCUSSION
National Weather Service Kansas City/Pleasant Hill MO
529 PM CST Fri Mar 3 2023
.Discussion...
Issued at 401 PM CST FRI MAR 3 2023
Key Messages:
- Warm This Weekend
- Light Rain Possible Saturday - Monday
- Midweek Weather System; Large Uncertainty
Discussion:
Negatively tilted trough axis has moved east of the Mississippi
River, and the 977mb surface cyclone has entered the western Ohio
River Valley. The precipitation associated with this system has moved
out of the forecast area. Mid to upper-level flow has become zonal
on the backside of the trough axis. Stronger height gradient
currently exists over and along the OK-KS and MO-AR statelines.
There is a weak H5 ridge axis over the High Plains of Kansas and
Nebraska, resulting in an AVA regime downstream into the forecast
area. This has promoted subsidence throughout the day, and the
clearing skies can be tracked on GOES 16 satellite imagery. The late
day insolation will allow western portions of the forecast area
including the KC metro to reach the 50s this afternoon. Eastern
portions of the forecast area will likely hang onto the cloud cover
a bit too long on the backside of the cyclonic flow, keeping
temperatures in the mid to upper 40s. This is also where heavier
rainfall occurred, and had more precipitation drag and evaporation
cooling during the afternoon hours. The winds will continue to
diminish through the night as the stronger pressure gradient trails
the exiting surface cyclone. With clear skies, calm winds, and
recent surface moisture recharge, fog cannot be ruled out. Current
RAP soundings do show the dewpoint depression decreasing this
evening, but do not quite achieve saturation near the surface. There
is some concern though the RAP may be trying to mix too much with
the late afternoon clearing. For now, have kept fog out of the
official forecast for this evening, but would expect low lying areas
to perhaps see some fog. Visibility observations will continued to
be monitored this evening and overnight.
Through the weekend and into Monday, the mid-level pattern can
generally be described as zonal. The first weak ridge axis currently
west of the area will pass through overnight, and provide us some
weak WAA. For Saturday this will keep temperatures in the mid to
upper 50s across most of the area, with lower 60s well south of
Interstate 70. There is a signal for weak isentropic ascent from
Topeka, KS to Bethany, MO that may result in light sprinkles or
areas of rain on Saturday. CAM soundings are showing some mid-level
saturation that could support this, but are very dry at the surface.
In addition, a weak vorticity max is expected to ride through the
zonal flow. While most the strongest portion of it will be over
Iowa, it may be enough to squeeze out light rain across western and
northern portions of the forecast area on Saturday. Rain
accumulations of only a few hundredths should be expected. That
vorticity max/short-wave trough moves into the western Great Lakes
Region by Saturday evening and allows subtle ridging within the H5
flow to move in overnight into Sunday morning. Expect surface to
850mb flow to turn south-southwesterly at and promote more WAA,
keeping temperatures on an upward trend into Sunday. Currently
forecasting temperatures in the mid 60s northward, where lingering
cloud cover may limit daytime heating. Central and southern portions
should reach the upper 60s, and may have a shot at hitting the lower
70s. The question will be how much moisture comes in behind the
ridge axis. If flow remains more southwesterly, skies should remain
clear and allow the higher end of likely temperatures to be
achieved. If the winds are more southerly and allow more moisture,
cloud cover may keep temperatures toward the median of most
guidance. The ridge axis though will keep any forcing away for most
of the afternoon and early evening, thus expecting dry conditions
with respect to precipitation on Sunday. Sunday evening, a short-
wave trough ejects out of the Rockies and moves across Nebraska and
Iowa. There is strong enough dCVA ahead of this vorticity maximum
that a surface cyclone develops and moves across the Central Plains
of Nebraska. Late Sunday Night and over night into Monday, this may
be able to result in light rain activity in northern Kansas and
Missouri. Rainfall accumulations again likely to be light, as the
better forcing stays closer to the base of the short-wave trough
which is currently progged to stay north of the forecast area.
Monday afternoon, the short-wave continues to moves eastward as the
flow generally remains zonal, and this pushes the center of the
surface cyclone into the Great Lakes Region. An H5 ridge develops
back of the Central and Northern High Plains, resulting in mid to
upper-level northwesterly flow. This pushes the trailing cold front
the surface cyclone southeast across the forecast area, and will
bring cooler temperatures Monday afternoon. Winds ahead of the cold
front will have been primarily southwesterly, keeping the air dry up
to around 700mb. Despite the enhanced convergence along the cold
front, the troposphere is looking too dry to support any substantial
rainfall event. The better support will be confined to areas
directly in the path of the surface cyclone and further east where
moisture advection will be stronger. Through Tuesday, H5 ridge moves
across the Central Plains. For most of the day Tuesday, flow remains
northwesterly after the cold frontal passage, which will keep
temperatures much cooler than compared to the warm temperatures over
the weekend. Still expecting dry conditions on Tuesday though as the
ridge will cause all forcing to move well northward.
For the middle of this upcoming week, a stronger PV anomaly is
expected to move across CONUS and result in multiple short-wave
troughs and vorticity maxima that will bring the next opportunity
for greater rainfall accumulations. The general time frame will be
sometime Wednesday through Thursday. Model guidance spread is quite
large though, mainly attributed to timing differences. The
deterministic GFS brings in an area of QPF early on Wednesday with
the first wave, while the ECMWF is not nearly as excited. The ECMWF
then brings in greater QPF by Thursday morning. In their respective
ensembles, there is large spread with respect to timing of the
arrival of the first short-wave trough across the region. The NBM
POPs remained relatively low, but in place for an extended period of
time. When the system moves through, would expect the rain shower
activity to be more concentrated over a shorter period of time. But
given the high uncertainty with the timing of the strongest forcing,
have left the lower POPs over a longer time period in the forecast.
For precipitation on Wednesday, most likely looking at rain as
temperatures will remain above 35. If precipitation lingers into
Thursday and colder air moves in during the evening, snow or a
rain/snow mix is possible. GEFS probabilities for at least one-
hundredth of an inch of liquid precip is over 60 percent for most of
the forecast area between Wednesday and Thursday, the main question
remaining at what exact time over that period. At this point, it is
tough to determine the extent of impacts.
Beyond the middle of next week, there is a signal for a stronger PV
anomaly to enter the western CONUS and moves across the nation. The
extended range guidance all vary in the exact strength. For Friday,
this could send a shot of WAA into the area, with precipitation for
next weekend.
&&
.Aviation...(For the 00Z TAFS through 00Z Saturday Evening)
Issued at 519 PM CST FRI MAR 3 2023
VFR conditions through the TAF period. Winds will become light
and variable overnight, shifting out of the south by Saturday
afternoon. Winds are anticipated to remain under 10 knots with dry
weather conditions.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
Discussion...Krull
Aviation...Klaus
Area Forecast Discussion
National Weather Service Goodland KS
227 PM MST Fri Mar 3 2023
.SHORT TERM...(This evening through Sunday night)
Issued at 130 PM MST Fri Mar 3 2023
Through Tonight: Mid-upper level cloud cover will increase from
the west this evening, as a progressive shortwave -- presently
situated in northern Utah -- approaches from the west. Light
precipitation -- snow or rain/snow (p-type may be rate-dependent
in northwest KS) -- will accompany this feature as it tracks
eastward across the Tri-State area tonight, mainly in the 03-09Z
time-frame. The progressive nature of the upper wave -- i.e.
relatively short `window of opportunity` -- suggests that
significant/impactful precipitation is unlikely. Simulated
reflectivity and precipitation forecasts via the latest (18Z) runs
of the HRRR and RAP suggest liquid equivalent precipitation
ranging anywhere from a few hundredths to 0.10-0.20" -- yielding
anywhere from a dusting to ~1" of snow accumulation -- mainly
along/north of I-70. Locally higher accumulation (1-2") cannot be
ruled out. Either way, significant impacts are not anticipated.
Cloud cover will decrease from west-east Sat morning.. via
subsidence in the wake of the aforementioned shortwave passage.
Sat-Sat night: A modest lee cyclone will develop in eastern
Colorado Sat eve-night as an upper level low -- presently situated
offshore British Columbia -- digs southward along the northern
Pacific Coast -- and flow aloft backs to the SW over the central
Rockies. With an evaporatively cooled airmass /weak meso-high/ in
place over the region (in the wake of precipitation early Sat
morning).. expect light/variable winds during the day and highs
cooler than today, ranging from the upper 30s to lower 50s. Low-
level southerly return flow will commence Sat evening.. in
response to pressure falls in the lee of the Rockies. SSE winds
may increase to 20-30 G 45 mph across portions of the area Sat
eve/night.. mainly in eastern CO and adjacent KS border counties
where the MSLP-H85 height gradient will be [relatively] tightest.
With breezy SSE winds.. expect lows warmer than previous nights..
ranging from the mid 20s to mid 30s.
Sun-Sun night: Guidance suggests that the aforementioned lee
cyclone will progress eastward across western KS (Sun aft) and
central/eastern KS (Sun eve/night). With the lee cyclone situated
more-or-less directly over the Tri-State area (i.e. a minimum in
the MSLP-H85 gradient) -- winds will predominately be a function
of vertical mixing. At present.. prolonged, deep (10-12 KFT AGL)
vertical mixing is most likely to occur along/south of I-70..
where forecast soundings indicate 30-40 knot WSW flow will reside
therein. Expect noticeably warmer temperatures.. with highs
ranging from the lower 50s (Yuma county) to mid-upper 60s (south
and east of Goodland) and breezy to strong WSW winds -- strongest
along/south of I-70 -- where locally reduced visibilities
associated with blowing dust can be expected.
The Fire Weather Watch remains in effect Sunday afternoon for
areas situated [roughly] along/south of I-70.. i.e. no changes.
.LONG TERM...(Monday through Friday)
Issued at 222 PM MST Fri Mar 3 2023
At the start of the long term period, models show the CWA having a
westerly zonal flow aloft with an upper air trough developing over
the Pacific Northwest on Monday. For Tuesday, forecast guidance
predicts the CWA`s upper air flow turning a bit west-southwesterly
as the western trough continues to develop with a ridge forming over
the Central Plains. On Wednesday, long term model solutions start to
diverge a bit particularly with the western trough as the ECMWF
starts to show it progressing slowly eastward by the afternoon hours
while the GFS does not move it until eastward until late
Wednesday. For Thursday, long term guidance does have the CWA
gaining a southwesterly flow aloft being between the trough in the
west and the ridge in the east with the ECMWF still showing a
quicker eastward progression than the GFS for the western trough.
Going into Friday, the GFS depicts an upper air low developing in
the base of the trough over the CO/UT border and giving the CWA a
southerly flow aloft by the afternoon hours. As an alternative,
the ECMWF projects the axis of the trough to slowly pass over the
CWA during the afternoon hours giving the CWA a northerly upper
air flow by Friday night. With the discrepancies seen between the
long term model solutions especially in the last few days of the
forecast period, these will be monitored for better consistency
going forward.
At the surface, models appear to be showing chances for
precipitation almost each day after Monday. Models generally agree
that Monday stays dry behind the previous day`s cold front passage.
On Tuesday evening and into the night, chances for light snow are
seen particularly for areas along and north of I-70 due to a surface
low developing in southeastern CO though there is some placement
differences in this low seen in the models. Minimal snowfall
accumulation looks to be expected with this precipitation. These
wintry precipitation chances appear to continue into Wednesday and
increase during the evening and overnight hours due to a shortwave
disturbance aloft. The snowfall intensity looks to change from light
to moderate on Thursday morning into the afternoon before returning
to light intensity by the evening as a surface low moves across
northern TX throughout the day. Models do show snowfall chances
continuing into Friday though lessening a bit as the aforementioned
surface low continues an eastern progression. Will continue to
monitor this midweek winter system as it does show some potential to
produce a few inches of snowfall across the CWA at the moment, but
there is some pretty low confidence in snowfall amounts due to
this event being quite a ways out still. It is worth mentioning
the ECMWF EFI for QPF and snowfall is +0.67 and +0.69 for 00Z Friday
now though for a good portion of the CWA. Fire weather does not
look to be a concern during the long period with minimum RH values
staying above the 15 percent criteria.
The Tri-State Area looks to see the warmest daytime highs on Monday
being in the lower 40s to lower 50s followed by highs in the middle
30s to lower 40s on Tuesday and Wednesday. Cooler daytime highs are
in the forecast on Thursday and Friday being in the upper 20s to
upper 30s range. Overnight lows on Monday through Wednesday
expect to be in the upper teens to middle 20s while lows on
Thursday and Friday night are forecasted to be in the lower to
middle teens range.
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 130 PM MST Fri Mar 3 2023
Occasional MVFR conditions are possible this evening and
overnight (04-08Z time frame).. mainly at the GLD terminal.. as
light precipitation (SN|SNRA) progresses eastward from northern
Colorado into northwest Kansas. VFR conditions will otherwise
prevail. Breezy (15-20 knot) NNW winds will veer to the N and
decrease to ~10 knots by sunset this evening, becoming light and
variable overnight. Light and variable winds will prevail through
late morning and early afternoon -- shifting to the SE and
increasing to 10-20 knots by late afternoon -- breeziest at the
GLD terminal.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...Fire Weather Watch from Sunday morning through Sunday afternoon
for KSZ013-027-028-041-042.
CO...Fire Weather Watch from Sunday morning through Sunday afternoon
for COZ254.
NE...NONE.
&&
$$
SHORT TERM...Vincent
LONG TERM...076
AVIATION...Vincent
Area Forecast Discussion
National Weather Service Lincoln IL
744 PM CST Fri Mar 3 2023
.SYNOPSIS...
Issued at 158 PM CST Fri Mar 3 2023
Temperatures will fall into the upper 20s tonight, then warm into
the mid 40s to mid 50s Saturday. Expect temps in the 50s area
wide Sunday. Dry weather is expected over the weekend, but breezy
conditions will return Sunday.
&&
.UPDATE...
Issued at 744 PM CST Fri Mar 3 2023
Deep low pressure that brought heavy rain, high wind, and a narrow
band of snow to central IL today is now tracking over northwest
Ohio. In its wake, the MSLP gradient is rapidly decreasing as weak
high pressure builds into the Mississippi Valley. This has allowed
winds to drop under 10 mph over the western CWA, while 25-40 mph
gusts were still blowing east of I-57. These will subside over the
next few hours. Clearing has already pushed through the central
CWA and the clear skies will overspread the rest of the area this
evening. Overnight lows should bottom out in the upper 20s to
around 30F.
&&
.SHORT TERM...(This evening through Saturday)
ISSUED AT 158 PM CST Fri Mar 3 2023
Widespread rain and snow, thunder, and strong winds are all in
place across central Illinois this afternoon. Gusts in excess of
60 mph have already caused damage and power outages across
portion of central Illinois. Heavy rain measuring one to two
inches has fallen along portions of the I-55 corridor and south of
the I-70 corridor where radar estimates that some localized
amounts over 2 inches have already occurred. Meanwhile, farther
north across Bloomington rain has transitioned to a wet, heavy
snow with large flakes and is beginning to stick to the grass and
elevated surfaces.
As of 1 pm this afternoon, deep 978mb low pressure center is
analyzed about a county south of Lawrenceville with a warm front
draped east-northeast into southern Indiana. Severe threat was
primarily along and south of the low track so this should keep the
central Illinois forecast area out of the severe storm threat the
rest of the day. A very tight pressure gradient is in place north
and west of the low center and anticipate gusts of 40 to 60 mph
to continue through this evening. HRRR suggests wind gusts will
peak between 21-23Z late this afternoon before shifting east into
Indiana after 00Z. The Wind Advisory was upgraded to a High Wind
Warning through 7pm for counties along and east of I-55.
Wintry precip is also starting to pick up across the region with
thundersnow or a rain/snow mix reported along much of the I-55
corridor. Latest RAP indicates a corridor or deep, sloped f-gen in
place from roughly the I-57 to I-55 corridor with banded precip
(and embedded storms) occuring along the cold side of this
enhanced mesoscale forcing. RAP shows the f-gen pivoting to the
east-northeast and exiting the state by around 00Z this evening.
Dynamic cooling within this band is allowing a transition over to
snow, with some sites still well above freezing reporting snow.
Fortunately a relatively warm boundary layer and pavement temps
are limiting accumulations to the grass and elevated surfaces so
far, but some reports of slippery roads are starting to come in
early this afternoon. A dusting up to an inch or two is still
possible along and north of the I-74 corridor east of Bloomington
through this evening. Precip will diminish between 00-03Z this
evening as the strongest forcing exits the state. Winds will also
begin to diminish below high wind warning/advisory criteria around
this time as the gradient begins to relax.
Fair weather returns to the forecast Saturday as high pressure
builds across the region. After starting the day in the mid to
upper 20s temps will warm into the mid 40s to mid 50s under a
light southwest breeze.
.LONG TERM...(Saturday night through Friday)
ISSUED AT 158 PM CST Fri Mar 3 2023
High pressure will be over the region Sunday shifting to the
eastern Great Lakes and Upper Ohio Valley through the day. To
our west, weak low pressure will develop over the central Great
Plains. South to southeast winds will pick up through the day
across central Illinois in between these two features. Expect
gusts to peak in the 25 to 35 mph range Sunday afternoon while
warm air advection helps drive temperatures back well above normal
with highs in the 50s and possibly a few 60s south of I-70. The
low is progged to lift from near Kansas City Sunday night to near
Milwaukee Monday. Breezy south winds and increasing cloud cover
will keep temperatures propped up Sunday night and set the stage
for us to warm into the 60s area wide Monday. Precip will be
favored to our north closer to the low track and leading warm
front, but a few spotty showers are also possible later Monday
near and north of I-74 along a trailing cold front.
Temperatures will trend back down through midweek behind the cold
front as a strong Canadian ridge of high pressure centered over
Manitoba extends southeast into the Midwest. Temperatures will be
more seasonable Tuesday and Wednesday with highs in the 40s.
Precip chances return late in the week as a southern stream wave
brings a chance for showers and storms to portions of the lower
and mid Mississippi Valley.
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 523 PM CST Fri Mar 3 2023
Strong low pressure was located over east central Indiana late
this afternoon. Tight pressure gradient on the back side of the
low was still producing northwest gusts near 40 kt at KCMI, but
gusts have been decreasing to the west. This trend will continue
this evening, with all gusts diminishing by 06z. IFR ceilings were
observed at KCMI at 23z, however ceilings are quickly rising to
the west, and clear skies are noted on satellite imagery over
western IL. So after a short period of MVFR ceilings shifting
east this evening, VFR skies are forecast through 00z Sun.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...25
SYNOPSIS...Deubelbeiss
SHORT TERM...Deubelbeiss
LONG TERM...Deubelbeiss
AVIATION...25
Area Forecast Discussion...UPDATED
National Weather Service Jackson MS
957 PM CST Fri Mar 3 2023
...New MESOSCALE UPDATE...
.MESOSCALE UPDATE...
Issued at 946 PM CST Fri Mar 3 2023
A weak surface high will continue to spread over our CWA from the
west and help bring cooler and drier air to the the region.
Satellite imagery showed a layer of stratus over our delta region
that models suggest wl spread east through Saturday morning. These
clouds will keep morning lows up a few degrees as compared to
clear skies. The current forecast accounts for the clouds and all
sites will bottom out in the 40s. /22/
&&
.DISCUSSION...
Issued at 219 PM CST Fri Mar 3 2023
Tonight-Saturday...
Tonight: Much quieter conditions are expected in the wake of the
line of severe storms that moved through this morning. RAP
synoptic/sfc analysis indicates upper low is quickly swinging to the
NE out of the MO Bootheel into W Kentucky. The sfc cold front is
quickly moving E into central to eastern AL. GOES-E water vapor
imagery indicates strong subsidence/dry punch moving across the
region, with much drier conditions at the sfc/aloft building in.
With nearly 5mb gradient, some gusty winds up to 30-40mph or brief
higher gusts are possible, but gradient winds will relax quickly as
the sfc low continues moving ENE into the evening. Will keep an
"Elevated" in the HWO/graphics & going wind advisory will remain in
effect through 6PM. Some gusty winds could persist briefly after.
However, quiet, dry night is expected as center of sfc high builds
over Mid-S. Light winds combined with cooler thermo/partly cloudy
skies will support lows falling into the mid-upper 40s.
Saturday: W-SW flow aloft & mean ridging will build through the
region to start the weekend. Combined with cooler low-level thermo
profiles & W-NW low-level flow, quiet, dry & slightly cooler aftn is
in store. Highs will peak in the upper 60s N to low-mid 70s S. Some
lingering low stratus could through midday but should be cleared out
by the aftn hours. /DC/
Saturday night through Thursday night...High pressure will prevail
over the area Saturday night, with lows falling mostly into the mid
40s. High pressure will continue on Sunday, but as the surface high
moves east of the area the flow will become more southeasterly. With
the more southerly flow, temperatures will warm into the
mid/upper 70s. A warm front will push northward on Monday and this
may kick off a few showers Monday into Monday night.
The ECMWF/GFS push a weak frontal boundary into the area on Tuesday
and this will continue to kick of a few showers across the area. The
boundary will hang around the region on Wednesday and Wednesday
night, with continued chances for showers/thunderstorms. Little will
change on Thursday as the stationary frontal boundary continues to
extend across the area. Showers/thunderstorms will continue to be
possible through Thursday night. /15/
&&
.AVIATION...
(00Z TAFS)
Issued at 553 PM CST Fri Mar 3 2023
A gusty west wind to 20kts wl continue until 01Z for the northern
TAF sites. After 01Z a lighter wind is expected and a lighter west
to northwest wind is expected through Saturday. VFR conditions wl
prevail through 03Z but a layer of MVFR stratus wl lower cigs from
the northwest through the night. MVFR cigs wl take until 18Z to
improve across the northern TAF sites but VFR conditions are
expected cntrl and south by 15Z. VFR conditions are expected
Saturday aftn and evng. /22/
&&
.PRELIMINARY POINT TEMPS/POPS...
Jackson 47 71 48 79 / 0 0 0 0
Meridian 47 72 47 77 / 0 0 0 0
Vicksburg 47 71 48 79 / 0 0 0 0
Hattiesburg 49 76 49 80 / 0 0 0 0
Natchez 47 72 49 79 / 0 0 0 0
Greenville 47 66 47 74 / 0 0 0 0
Greenwood 47 67 48 76 / 0 0 0 0
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...None.
LA...None.
AR...None.
&&
$$
DC/15/22
Area Forecast Discussion
National Weather Service North Platte NE
934 PM CST Fri Mar 3 2023
...UPDATED DISCUSSION FOR WINTER WEATHER ADVISORY...
.SYNOPSIS...
Issued at 329 PM CST Fri Mar 3 2023
- A period of light snow is expected tonight across north central
Nebraska and also across portions of the southeast panhandle
into southwest Nebraska. Accumulations of 1 to 3 inches possible
mainly northern Sheridan into Cherry County.
- A significant change in the weather pattern next week with much
colder temperatures and chances for accumulating snow.
&&
.UPDATE...
Issued at 935 PM CST Fri Mar 3 2023
Snow continues to overspread areas of southwestern South Dakota
and adjacent northwest Nebraska. NDOT road cameras are beginning
to show quick accumulations across portions of the northern
Panhandle.
Recent high-res guidance solutions have come into better
agreement with a narrow swath of potentially heavy snowfall
amounts near the HWY 20 corridor in northern Nebraska. This is a
direct result of convective enhanced snowfall rates, with steep
lapse rates noted in forecast soundings, nonzero MUCAPE, and deep
ascent through much of the vertical column. A period of 1"/hr
snowfall rates look increasingly probable near the SD/NE state
line in the 06-09Z timeframe, with a growing number of high-res
ensemble members suggesting this potential. With this in mind,
have increased QPFs/snowfall totals across much of northern
Sheridan/Cherry counties where the greatest threat of enhanced
snowfall rates exists. With new snow accumulations around 3" for
the HWY 20 corridor, have hoisted a Winter Weather Advisory for
Sheridan and Cherry counties. One big caveat, with convectively
enhanced snowfall rates, locally higher amounts will be very
possible, and this will continue to be monitored closely.
&&
.SHORT TERM...(This evening through Saturday night)
Issued at 329 PM CST Fri Mar 3 2023
An upper trough, currently located across western Wyoming and far
eastern Utah will move across the forecast area tonight. Another
area of light snow is in agreement by the 12Z NAM, HRRR and RAP
bringing an area of light snow across the southeast panhandle into
southwest Nebraska . Have likely POPs across most of Cherry and
Sheridan County tonight with snowfall amounts from 1 to 3 inches.
This is similar to the the previous forecast. Some chance POPS
also exist further south across the southeast pnhdl and southwest
Nebraska overnight where snowfall amounts up to an inch are
possible. This system will have some weak instability and
convective elements to support some brief higher snowfall rates.
A cold front will move in later tonight behind the system.
On Saturday, a slight chance for light snow is possible until mid
morning across the northeast as the upper trough exits the area.
Slightly cooler from the upper 30s to lower 40s with weak mixing
expected.
Saturday night, surface low pressure will extend up along the
Front Range. This will bring an increase in southeast winds to 15
to 25 mph. Lows not as cold from the upper 20s to around 30 most
locations. There will also be a disturbance in southwest flow
aloft providing a chance for light snow to northern Nebraska. Not
expected much in the way of snowfall, with the better potential
across South Dakota.
.LONG TERM...(Sunday through Friday)
Issued at 329 PM CST Fri Mar 3 2023
On Sunday, warm air advection will occur across the area as
southwest winds turn westerly in the afternoon. Highs should reach
50 degrees or warmer. This will be followed by a strong cold front
moving through Sunday night.
An upper trough across the northwestern U.S early next week is
forecast to deepen over the Great Basin through Wednesday. Medium
range models are beginning to come into agreement that the upper
trough may develop a closed low near the Four Corners Region on
Thursday. Ensemble guidance also supports this. Confidence remains
low, but is increasing that a significant system may evolve across
the Central and Northern Plains by Thursday and Friday. This will
bring increasing chances for snowfall as the week progresses. Will
need to monitor model trends closely.
Much colder temperatures are forecast next Tuesday through Friday.
Highs by next Thursday and Friday are only expected to have highs
from the mid 20s to around 30, which is at least 20 degrees below
normal for this time of year.
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 526 PM CST Fri Mar 3 2023
For the KLBF terminal: Expect mainly cloudy skies through midday
Saturday. Ceilings will lower to 4000 to 8000 FT AGL overnight
with showers in the vicinity of the terminal. Ceilings will then
rise to 8000 to 15000 FT AGL Saturday morning. Skies will then
clear out Saturday afternoon with scattered clouds around 25000 FT
AGL. For the KVTN terminal: Ceilings will continue to lower into
the evening hours, reaching around 2000 FT AGL overnight. Light
snow will be possible after 07z with visbilities as low as 2SM.
Snow showers are expected to end by sunrise Saturday with ceilings
increasing to 7000 FT AGL Saturday morning, then 20000 FT AGL
Saturday afternoon.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until 6 AM CST /5 AM MST/ Saturday for
NEZ004-005-094.
&&
$$
UPDATE...Brown
SYNOPSIS...Roberg
SHORT TERM...Roberg
LONG TERM...Roberg
AVIATION...Buttler
Area Forecast Discussion
National Weather Service Morristown TN
1014 PM EST Fri Mar 3 2023
...New UPDATE...
.UPDATE...
Issued at 1008 PM EST Fri Mar 3 2023
The main change with the update was an early cancellation of wind
products for much of East Tennessee and southwest North Carolina.
Observations for the last 2 hours have continued to suggest a
downward trend in winds from central East Tennessee southward.
This coincides with the current high-res placement of the LLJ and
weakening observed MSLP gradient. An SPS was issued for the
Tennessee areas due to lingering gusty winds through at least the
next 3 hours or so. Places in the northeast are still seeing gusts
near or above 40 kts with similar indications in the mountains as
well, so these places were allowed to continue. It is certainly
possible that these zones will need to be cancelled early as well
but not at this time. Additionally, temperatures have been milder
than expected, largely due to a slower CAA with the approaching
front. Hourly values were updated to reflect this trend. PoPs were
also eliminated due to a quicker exiting of remaining showers.
&&
.SHORT TERM...
(This evening through Saturday)
Issued at 250 PM EST Fri Mar 3 2023
Key Messages:
1. Line of showers and storms currently moving through the
central East TN Valley still pose a risk of strong damaging wind
gusts and isolated tornadoes. This threat continues east into
northeast TN and southwest VA over the next few hours.
2. Strong damaging non-thunderstorm wind gusts continue areawide
through this evening, even behind the line of showers and storms.
3. The possibility of widespread tree and powerlines damage
continues into the evening hours.
A line of showers and storms currently moving through the central
East TN Valley still pose a risk of strong damaging wind gusts
and isolated tornadoes. This threat continues east into northeast
TN and southwest VA over the next few hours. A tornado watch
remains in effect for most areas. See latest watch products for
more details. At the current hour, shear values remain very high
across the area with a few hundred J/kg SBCAPE, which is why the
tornado threat continues. Aside from tornado threat, any stronger
showers and storms could transport higher winds aloft down to the
surface with wind gusts in excess of 70 mph due to the 70kt 850mb
jet that remains overhead.
Outside of the showers and storms, strong and gusty winds continue
areawide due to the gradient winds. These higher gusts will
continue behind the line as the cold front approaches and moves
through and a High Wind Warning continues for all areas through
this evening.
Latest HRRR runs show showers and storms exiting east between 23Z
and 00Z tonight, but again, strong winds will continue behind
this line. Temperatures fall into the upper 30s to low 40s late
tonight behind the cold front.
Saturday looks dry with clouds clearing from late morning into
the early afternoon hours. Temperatures will be cooler with highs
in the lower 50s to low 60s.
&&
.LONG TERM...
(Saturday night through next Friday)
Issued at 250 PM EST Fri Mar 3 2023
Key Messages:
1. Less active by chances of rain Monday night/Tuesday morning and
again Wednesday night through Friday. Rainfall amounts will
generally be light.
2. Temperatures will range from near normal to above normal through
the period.
Discussion:
Weak flow aloft will encompass most of the long term period. Late
this weekend, high pressure will dominate the Tennessee Valley
promoting dry weather conditions, and near normal temperatures. Late
Sunday and into early next week, flow turns toward the south
advecting warmer air poleward. This also proceeds an area of low
pressure that is expected to quickly lift into the midwest and Ohio
Valley. An attendant front will progress through the area Tuesday
with chances of showers along and ahead of the front.
Forecast confidence decreases mid/late week as an upper level trough
moves into the plains. Low pressure is expected to develop across
the south before lifting north across the Southern Appalachians.
Chances of showers will increase Wednesday through the end of the
period. Temperatures during this time period will be near to above
normal.
&&
.AVIATION...
(00Z TAFS)
Issued at 607 PM EST Fri Mar 3 2023
Remaining showers and storms will continue to move off to the east
of the area with the main story being the continued strong
southwesterly winds. Gusts could exceed 35 kts through the evening
hours. These winds will gradually lessen through the night but
will likely remain gusty until the morning hours. Regarding
ceilings, reductions to MVFR are expected at TYS and TRI with TRI
possibly seeing periods of IFR by the early morning. CHA is most
likely to stay VFR through the night. TRI will be slow to clear
tomorrow with a light, more northerly wind expected through the
day.
&&
.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN 42 63 40 69 / 0 0 0 0
Knoxville McGhee Tyson Airport, TN 41 59 36 66 / 0 0 0 0
Oak Ridge, TN 40 61 37 66 / 0 0 0 0
Tri Cities Airport, TN 39 56 33 64 / 30 0 0 0
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...High Wind Warning until 6 AM EST Saturday for Hancock-Hawkins-
Johnson-Northwest Carter-Northwest Greene-Southeast Carter-
Southeast Greene-Sullivan-Unicoi-Washington TN.
High Wind Warning until 1 AM EST Saturday for Blount Smoky
Mountains-Cocke Smoky Mountains-Sevier Smoky Mountains-
Southeast Monroe.
VA...High Wind Warning until 6 AM EST Saturday for Lee-Russell-Scott
VA-Washington VA-Wise.
&&
$$
SHORT TERM...SR
LONG TERM....Diegan
AVIATION...BW
Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
821 PM MST Fri Mar 3 2023
.UPDATE...
Issued at 819 PM MST Fri Mar 3 2023
Potent compact shortwave with unstable profiles in the DGZ
continues to support impressive snow bands across southwest into
scentral SD. Have issued an adv for areas along the NE border
where hires models are progging strong FGEN tonight, with adv
levels snow expected.
&&
.DISCUSSION...(This Evening Through Friday)
Issued at 101 PM MST Fri Mar 3 2023
Water vapor shows short wave moving through WY with broad trof
offshore the Pac NW coast. At the surface, cold front that moved
through overnight and this morning has shifted well south of the
forecast area. Radar imagery showing increasing signatures across
the central/southern Black Hills as lee side convergence
strengthens.
An uptick is snow is still anticipated this afternoon/evening
across the central/southern Black Hills and southwest into south
central SD, as short wave currently over WY moves across and low
level lapse rates strengthen. Higher probabilities for advisory
level snow are still highest in both the NBM and HREF around and
east/southeast of Custer. Control runs of the HRRR, RAP show
higher amounts of snowfall onto the plains south/southeast of the
Black Hills, but this is not well supported with ensemble
solutions. Most snow amounts on the plains are expected to remain
under 3 inches. Still have relatively high probabilities (30-50%)
of 1+ inch snowfall rates this afternoon/evening in areas of
Custer State Park and Wind Cave National Park, within the Winter
Weather Advisory. There is some potential for this heavier snow to
extend up into the central Black Hills, and will need to be
monitored the rest of this afternoon/evening. Snow should end from
west to east after midnight and be mostly out of our forecast
area around daybreak Saturday.
For Saturday, short wave ridge behind departing short wave trof
will bring dry west/southwest winds and highs into the 30s through
mid 40s, warmest east of the Black Hills.
Next ejecting short wave arrives Saturday night, with broad
isentropic lift setting up across our northern zones. Could be a
few inches in/around the Black Hills with the initial warm
advection push Saturday evening, before the steadier snow sets up
further north. That snow will continue into Sunday morning before
the main short wave slides through. NBM probabilities for 6+
inches in far northwest SD are in the 15-30% range, with higher
probs into ND and parts of North Central SD. Could also be another
minor burst of snow across the northern Black Hills Sunday Night
with a bit of upslope setting up behind the main short wave.
Short wave ridge crosses early Monday, with cold northerly winds
as surface ridge builds south into the Northern Plains. Snow
chances increase again late Monday as next ejecting short wave
overruns the colder air mass at the surface.
High confidence in much colder weather through next week with
periods of snow with each passing short wave ahead of the main
upper trof developing over the western CONUS. Most likely periods
of snow are Tuesday into Wednesday, with a possible brief break
before more snow develops Thursday into Friday.
&&
.AVIATION...(For the 00Z TAFS Through 00Z Saturday Evening)
Issued At 420 PM MST Fri Mar 3 2023
Snow with areas of MVFR conditions (localized IFR/LIFR conditions
in heavier snow) will continue across portions of northeastern
WY, the Black Hills, and southwestern SD this evening. Conditions
will improve from west to east late tonight. Elsewhere, VFR
conditions should prevail through the period.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...Winter Weather Advisory until midnight MST tonight for SDZ028-
029-074.
Winter Weather Advisory until 5 AM MST /6 AM CST/ Saturday for
SDZ042-044-047.
WY...None.
&&
$$
Update...JC
DISCUSSION...Johnson
AVIATION...JC