Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 01/06/24
Area Forecast Discussion
National Weather Service Binghamton NY
1102 PM EST Fri Jan 5 2024
.SYNOPSIS...
A strong coastal storm pushes in mid day Saturday. Accumulating
snow will move in during the afternoon and continues into
Sunday. High pressure and dry weather moves in Monday.
&&
.NEAR TERM /THROUGH SATURDAY/...
920 pm update...
Made changes to the cloud cover with the low clouds retreating
north to Syracuse and Utica. So far the Montague radar is not
showing any snow showers/flurries in Oneida and Onondaga
Counties. Few clouds south of that so temperatures have fallen
into the teens. Will adjust hourly and min temps down. Mid and
high clouds move in quickly from the west in the next few hours.
Saturday into Sunday afternoon will be cloudy.
345 pm update...
Tonight is expected to be quiet with weak upper level riding
moving through ahead of the approaching low pressure system.
With mostly clear skies to start, lows will fall into the low to
mid 20s before mid and high clouds begin to advect in.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/...
345 PM Update:
A low pressure system moves from the Carolinas up to off of the
Mid- Atlantic coast Saturday with snow overspreading the region
late morning into the afternoon.
Synoptic overview: Recent trends in the models have been back
towards a more amplified shortwave with better phasing with the
northern wave. Better lift over towards the Ohio River Valley
has helped with shifting the storm farther west with stronger
FGEN across CNY and the Twin Tiers. The 850 mb low looks to
close off farther to the west as well over central PA with
strong easterly flow just N of it across NEPA. This is advecting
in warmer air and forecast soundings are showing temperatures
approaching freezing aloft near the Poconos and this could
reduce snow totals as some sleet may mix in. An inverted trough
develops as the low deepens off shore late Saturday night into
Sunday helping to keep widespread light snow going across much
of CNY while it is starting to look like a dry slot moves into
NEPA and bring an end to the snow by early Sunday briefly. Wrap
around moisture and weak lift with a saturated DGZ will help
keep light snow persisting Sunday.
Snow: With the track of the low passing to the SE of CNY and
NEPA, it is looking like the precip type will be mostly snow
with only a small possibility of some mixed precip in parts of
the Poconos and the Wyoming Valley. The WPC snowband tool shows
good consistency between the HREF and HRRR with a snow band
lifting northward impacting NEPA in the mid afternoon and
propagating into CNY by the late afternoon and early evening.
There is greater probability of inch per hour snowfall rates in
NEPA as there is better 850-700 mb FGEN as well as 700-500 mb
FGEN. Though recent westerly trends may push this better forcing
into the Twin Tiers and will need to be watched with the
evening and overnight runs. Winter storm warnings have been
hosted for most of the I-81 corridor and east with Onondaga left
out for now being on the northern edge of the snow. Advisories
have been issued for now for the western Southern Tier into the
Finger Lakes as confidence of the heavier snow amounts are lower
with the better forcing back towards the SE. Snow winds down
Sunday evening with only some scattered lake effect showers
Sunday night so all warnings and advisories expire Sunday
evening. The biggest possible failure mode is the strong
easterly winds aloft when the heaviest snow is expected to move
through with downsloping off the Catskills overpowering the FGEN
across the Twin Tiers into southern CNY. Snow ratios will be
around climatology with near 10:1 in NEPA (lower where sleet
mixes in) and then around 12-13:1 across CNY. Storm total snow
will mostly be around 6 to 9 inches in the warning area with the
lower amounts in the valleys so most of the urban areas may
stay below warning amounts but higher elevations above 1000 feet
are more likely to see at least 7 inches of snow. With the
easterly flow at 850 mb, eastern slopes of the Catskills may see
isolated 12+ inch amounts. The increased probability of warm
air advecting into the Poconos have lowered the potential to see
some of the higher end amounts.
Impacts: While this storm is not too anomalous for our area it
is the highest amounts that we have seen in almost a year.
Snowfall rates will be the main impact from mid afternoon
tomorrow into the evening. With ratios being largely 10:1 or
higher, snow loading on power lines and tree limbs is unlikely.
Winds is also not an issue at the surface so areas of blowing
snow will be limited to areas with large open fields.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
350 PM Forecast...
A quiet Monday is expected before a strong low pressure system
moves into the region for Tuesday and Wednesday.
An upper level ridge with associated surface high will slide
eastward Monday, bringing quiet conditions to the region.
Temperatures will be in the low to mid 30s during the day and
low to mid 20s Monday night.
A deep upper level trough will dig into the central US Monday
night into Tuesday morning. This will swing our overall wind
pattern from WNW to SW, advecting in warm, moist air from the
south. The upper level, mid level and surface low will stack on
top of each other and track from Missouri into the Great Lakes.
This track with the center of the low west of our CWA will push
warm air into the region, making this a mostly rain event vs.
the storm we are expecting to occur this weekend. Initial
precipitation is expected to begin Tuesday afternoon and start
off as snow or a rain/snow mix before transitioning to all rain
in a SW to NE direction. The initial precip could have some
sleet or freezing rain mixed in but current confidence in this
is too low to include it in the forecast given thermal profiles
are borderline in this model cycle. Temperatures will climb from
the low to mid 30s Tuesday to mid to upper 40s by Tuesday night.
As the low approaches the Great Lakes, it is expected to deepen
and generate a very tight pressure gradient across the NE US.
This will bring strong and gusty winds to the CWA Tuesday night
into Wednesday morning, with gusts currently forecast to reach
40-45mph across the entire CWA. The heaviest rain is expected to
occur Tuesday night into Wednesday morning as a very strong low
level jet is expected to develop off the Mid- Atlantic coast,
pumping high moisture into the storm as the strongest lift is
occurring over the CWA. Luckily, the storm is moving at a
pretty good pace and should be out of the region by Wednesday
evening, with some lake effect snow showers hanging around into
Thursday morning.
The already saturated ground combined with heavy rain and very
strong winds could bring downed trees and power outages
starting Tuesday night. For a discussion on the flood potential,
please see the hydrology section below.
On Friday a weak, quick hitting shortwave will graze the area.
Track and timing are still somewhat uncertain but it looks like
areas north of the Southern Tier have the best chance at snow
showers Thursday night into Friday.
&&
.AVIATION /04Z SATURDAY THROUGH WEDNESDAY/...
Lake effect clouds are expected to produce MVFR conditions
tonight at RME and as the evening progresses SYR as well. There
is the potential for ceilings drop as low as fuel alt. at both
terminals with confidence higher in that occurring at RME vs.
SYR. Both terminals will become VFR tomorrow morning before
ceilings lower later in the TAF period as snow begins to
approach from the south. ITH can reach high-level MVFR levels
overnight as the lake effect clouds shift south, but will be VFR
tomorrow morning.
VFR conditions are expected this evening through tomorrow
morning at ELM, BGM and AVP before ceilings begin to lower in
the afternoon ahead of the approaching winter storm. As snow
develops from south to north, IFR visibilities are expected to
develop with the potential tomorrow evening near or just after
the end of the TAF period for lower than IFR restrictions during
the heaviest of the snow. Something else that will have to be
monitored is the potential for LLWS as NAM soundings show
borderline easterly LLWS for AVP and perhaps RME toward the end
of the TAF for a few hours.
Outlook...
Saturday night through Sunday...IFR restrictions likely with
snow.
Sunday night through Monday...Restrictions in wrap around lake
enhanced snow showers. Less at AVP. Slow improvement Monday from
southwest to northeast.
Tuesday...VFR in the morning but restrictions possible during
the afternoon with mixed precipitation and strong winds.
Wednesday...Restrictions possible from rain and wind.
&&
.HYDROLOGY...
Strong low pressure moving through the region Tuesday-Wednesday will
bring deep moisture, mild temperatures and strong winds to the area
to help fuel an increased flood risk for the Upper Delaware and
North Branch Susquehanna basins. The Chemung basin and the
Oswego drainages appear to be at a reasonably lower risk for the
moment. The finer details of any flood risk will be determined
closer to the event, but the latest ensemble probabilities of
rainfall, runoff and stream level rises point toward an enhanced
flood threat for the Western Catskills and northeastern
Pennsylvania counties where our guidance is indicating a 60-80
percent chance for 2 or more inches of rainfall. This combined
with a good chance that temperatures may surge well into the 40s
overnight Tuesday into Wednesday will result in additional
water melting away from the snow pack forecast to develop this
weekend.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...Winter Storm Warning from 11 AM Saturday to 7 PM EST Sunday
for PAZ038>040-043-044-047-048-072.
NY...Winter Weather Advisory from 3 PM Saturday to 7 PM EST Sunday
for NYZ009-016>018.
Winter Weather Advisory from 1 PM Saturday to 7 PM EST Sunday
for NYZ015-022>025.
Winter Storm Warning from 3 PM Saturday to 7 PM EST Sunday for
NYZ036-037.
Winter Storm Warning from 1 PM Saturday to 7 PM EST Sunday for
NYZ044>046-055>057-062.
&&
$$
SYNOPSIS...AJG/TAC
NEAR TERM...AJG/TAC
SHORT TERM...AJG
LONG TERM...JTC
AVIATION...DK/JTC
HYDROLOGY...
Area Forecast Discussion
National Weather Service Buffalo NY
935 PM EST Fri Jan 5 2024
.SYNOPSIS...
There may be a few light snow showers east of Lake Ontario
overnight, otherwise it`ll be dry overnight. Low pressure will
then move through the lower Ohio Valley Saturday afternoon, then
redevelop and deepen along the southern New England coast
Saturday night through Sunday. This system will bring some
modest accumulating snow to much of the region Saturday
afternoon through Sunday, with the greatest accumulations over
the southeastern portions of the area and the least amounts near
the Canadian border.
&&
.NEAR TERM /THROUGH SATURDAY NIGHT/...
There`s just not enough moisture given the low inversion levels
at around -10C to get much lake effect going, so dropped PoPs
further east of Lake Ontario. Can`t rule out some light snow
showers or flurries, which will shift over Lake Ontario late
tonight. Little to no accumulation. Elsewhere, it`ll be dry.
Clear skies across the Western Southern Tier will allow better
radiational cooling there where lows will be in the teens. Cloud
cover will keep temps in the 20s elsewhere.
Our attention then turns back to the synoptic scale. A partially
phased pair of shortwaves will move across the Great Lakes and Ohio
Valley Saturday, with the southern wave containing the deeper
moisture and stronger forcing responsible for spinning up secondary
coastal cyclogenesis off the Jersey Shore by Saturday evening. This
rapidly deepening coastal low will then move northeast just off the
southern New England coast by Sunday morning. An initial surge of
warm advection and moisture transport, along with DPVA and upper
level divergence will move northeast across the eastern Great Lakes
Saturday afternoon through the first half of Saturday night, with
forcing and moisture supporting a period of widespread snow crossing
the area from southwest to northeast.
12/18Z guidance continues to trend faster with this first phase
of the system, with an earlier start time and also earlier exit
time. 00Z HRRR also supports this idea. Expect snow to develop
first across the western Southern Tier by early afternoon
Saturday, reaching the I-90 corridor from Buffalo east into the
Genesee Valley and western Finger Lakes by mid to late
afternoon, then the eastern Lake Ontario region by early
evening. The quality of deep moisture and forcing will generally
increase with southeastern extent, allowing the southeast edge
of our CWA from the upper Genesee Valley into the western Finger
Lakes and southern Tug Hill region to see somewhat higher snow
intensity and longer duration, with the lightest intensity and
shortest duration found near the Canadian border. This first
batch of snow will be in and out, followed by a dry slot and
break in the snow as early as mid to late evening over Western
NY, and then overnight for points farther east. Additional light
wrap around snow will move back into Western NY by very late
Saturday night/early Sunday morning.
Accumulations Saturday afternoon through Saturday night will be
greatest over the southeastern edge of our CWA, from Allegany County
through the western Finger Lakes to the southeast corner of Lake
Ontario and the southern Tug Hill. Expect a general 3-5" in this
area, with a few isolated 6" reports possible mainly across higher
terrain. Snow accumulations will then decrease with northwest
extent, down to 2-3" around Rochester, and only 1-2" at most near
Lake Erie including the Buffalo Metro and Niagara Falls. There will
be some additional minor accumulations during the day Sunday, more
on that in the short term below.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
Coastal low pressure that brought the steadier general snows to
portions of the area Saturday will move slowly east-northeast from
just off the southeastern New England coast to east of Cape Cod on
Sunday. That said, a trough will extend back across our region from
the low keeping at least some light wraparound snow shower activity
going across the area through the day, steadiest of which will be
across the eastern Lake Ontario region through early afternoon. A
west to west-northwest flow will set up across Lake Erie NY with
850mb temps around -7C/-8C, which is marginal for a true lake
response, but plenty cold enough to bring some lake enhanced
activity in across areas east of Lake Erie with lingering synoptic
moisture in place. Most areas south of Lake Ontario will will see an
inch or less of addtional accumulation through the day. However,
combination of localized lake enhancement/upslope flow may squeeze
out a couple more inches across the higher terrain of Chautauqua,
southern Erie, and northwestern Cattaraugus counties. An additional
1-2 inches will also be possible east of Lake Ontario in the more
widespread wraparound snows. Highs mainly in the low to mid 30s,
with some mid and upper 20s Tug Hill/western Dacks.
Coastal low pulls east into the Atlantic Sunday night, taking the
surface trough across our area with it, which will make way for a
large area of double barrel high pressure to approach from the west.
Cool westerly flow will continue off Lake Erie with a northwesterly
flow off Lake Ontario, keeping some lake enhanced snow showers going
east and southeast of both Lakes respectively with some additional
light accumulations possible, mainly an inch or less. Low temps
mainly in the 20s, with mid/upper teens Tug Hill/western Dacks/SL
valley.
A few scattered light lake enhanced snow showers may linger into the
first part of Monday morning, before high pressure ridges in across
the area Monday and Monday night with associated subsidence and
drier air bringing a brief period of quiet weather for Monday
afternoon and Monday night. Will tack on a few degrees for Monday
with highs mainly ranging through the 30s, upper 20s Tug
Hill/western Dacks. Strengthening southeasterly flow sets up Monday
night in advance of the next system, with lows mainly ranging
through the 20s, with these likely occurring first half of the
night, then either remaining steady or rising through early Tuesday
morning.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
...Strong Winds Likely Tuesday and Wednesday...
This afternoon a well defined upper level low is seen on GOES-18
water vapor imagery off the coastline of British Columbia. This
feature will drop across the Rockies and into the deep southern
Plains where it will form a surface low to the lee of the Rockies,
and deepen this surface low as it tracks across the Mississippi and
Ohio Valleys. A negatively tilted upper level trough will send this
surface low very near our region, with still model uncertainty to
whether this low tracks just to our west, or in an elongated form
tracks across our region. The ultimate track will have bearings upon
wind, as well as precipitation type.
For this forecast will continue towards continuity/ siding towards a
more western track with the surface low.
Precipitation Tuesday likely to start in the form of snow will
overspread our region from southwest to northeast. A strong,
southerly 70 to 80 knot LLJ will advect milder air northward in the
lower levels changing snow over to rain. Gusty surface winds will
also support temperatures across WNY rising towards 40 to mid/upper
40s in the downslope regions. This southerly flow will also stand a
good chance to mix down to the surface with advisory level gusts for
much of the region. Though a steepening inversion with the falling
precipitation, the base of this LLJ is just a thousand feet above
the surface and below the inversion and it will not take much to
bring these winds down to the surface. Strongest gusts will likely
be the northwest face of the Chautauqua Ridge and Tug Hill where
southeast winds will accelerate within the downslope regions of
these areas. If the surface low does take a more eastward track over
our region Tuesday and Tuesday night, then the axis of the LLJ will
be eastward, and these southerly winds will not be as strong.
The greatest potential for advisory snow amounts continues to be
east of Lake Ontario on the Tug Hill. Rain will be predominate
Tuesday night with the cold air still off to the west. Latest NAEFS
brings PWATS of 2-3 SD across our region Tuesday night. Will
highlight moderate rain in the forecast for the Southern Tier,
Genesee Valley and then onto the North Country. Here, rainfall
amounts over an inch will be possible.
As this surface low ends the deepening phase, and now behind the low
winds at the surface may not be as strong as what was experience in
the warm sector. The axis of the very strong LLJ will now be to the
east, though increased mixing efficiently within the CAA will still
support westerly gusts that may near advisory levels to the east of
the Lakes Wednesday.
Cold air deepening in the westerly flow will also bring some minor
lake effect snow east of the Lakes Wednesday night. Temperatures at
850 hPa lower to around -8C Wednesday night which over a lake that
still sits at +5 to +6C will be enough instability to generate bands
of lake snow. Still not looking like a major event with lake induced
equilibrium levels rising to around 5K feet, moisture not too
plentiful in the snow dendritic growth zone and an approaching ridge
Thursday likely to maintain a fair amount of shear before eventual
drier airmass crosses the lakes.
This ridge will be fast moving as the 12Z model guidance of the
ECMWF and GFS bring another shortwave trough and surface storm into
the Great Lakes region for Friday. Precipitation along a warm front
extending eastward across the Eastern Great Lakes will be possible
for Friday. At this point in the forecast, initially cold aloft to
support snow, increasing temperatures along the warm frontal push
will change precipitation over to rain. None the less an active
period continues as we near mid-January.
&&
.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
Satellite imagery shows lingering MVFR stratus from KBUF-ROC
northward during this evening, and this will eventually
lift/dissipate later tonight with the wind shift. KJHW has
already cleared to VFR. After 06Z, expect mainly VFR flight
conditions in mid/high clouds.
Mainly VFR likely to persist on Saturday until snow moves in.
Large scale snow will move in Saturday, dropping visibility to
1-2SM at most TAF sites after it starts, but the steadier snow
will only last about 6 hours.
Outlook...
Saturday night...IFR/MVFR. Snow tapering to snow showers from
west to east.
Sunday...Periods of light snow with MVFR/IFR.
Monday...Mainly VFR.
Tuesday...Snow or rain developing, changing to mainly rain later
Tuesday and Tuesday night. Deteriorating to MVFR/IFR. Very windy.
Wednesday...Rain changing back to snow, with areas of MVFR/IFR. Very
windy.
&&
.MARINE...
Pressure gradient will temporarily lax overnight as high
pressure briefly builds in ahead of an approaching low pressure
system. Small craft headlines for eastern Lake Ontario are set
to drop off at 1 a.m. as winds and waves continue to diminished
Low pressure will then move into the Ohio Valley Saturday, then
redevelop and strengthen off the southern New England coast Saturday
night and Sunday. A period of moderate easterlies will develop
Saturday through Saturday evening on Lake Ontario, and may bring
another round of Small Craft Advisory conditions to the west half of
the lake. These easterlies will then diminish overnight Saturday
night, and then swing around to the northwest Sunday through Sunday
night behind the departing east coast system.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...Winter Weather Advisory from 4 PM Saturday to 4 AM EST Sunday
for NYZ004-005-014.
Winter Weather Advisory from 7 PM Saturday to 7 PM EST Sunday
for NYZ006-008.
Winter Weather Advisory from 1 PM Saturday to 4 AM EST Sunday
for NYZ021.
MARINE...Small Craft Advisory until 4 AM EST Saturday for LOZ044-045.
&&
$$
SYNOPSIS...Hitchcock
NEAR TERM...Apffel/Hitchcock
SHORT TERM...JM
LONG TERM...Thomas
AVIATION...Apffel/Hitchcock
MARINE...Apffel/Hitchcock
Area Forecast Discussion
National Weather Service Corpus Christi TX
542 PM CST Fri Jan 5 2024
...New AVIATION...
.SHORT TERM...
(Tonight through Saturday night)
Issued at 313 PM CST Fri Jan 5 2024
Key Messages:
- Brief patchy fog early Saturday morning and again late Saturday
night.
Surface high pressure and flat ridging aloft will continue to bring
drier air across S TX tonight, leading to mostly clear skies
overnight. With light and variable winds expected tonight combined
with clear skies and a dry airmass, will allow for maximum
radiational cooling. Lows tonight will fall into the mid 40s along
the Rio Grande, southern Brush Country and along the Coastal Bend.
The northern Brush Country will see mid to upper 30s. Can not rule
out a few locations in the drainage areas around Choke Canyon
briefly dipping down to freezing around sunrise, but the chance is
very low (<10%). Temperatures are expected to be 1-3 degrees warmer
for Saturday night.
The NBM indicated fog developing across the interior Coastal Plains
by early Sat morning with visibilities down to 1/2SM at some
locations. The HRRR and RAP also indicate visibilities dropping, but
forecast soundings do not look conducive for fog with a wide
temp/dewpt spread. The SREF probability of the visibility dropping
below 1SM is less than 10 percent. However, the moist soil from the
recent rain may be sufficient for shallow fog to develop. Thus, have
included a mention of patchy light fog developing around sunrise
Saturday morning. There is a slightly better chance (10-20%) of fog
developing after midnight Saturday night.
A pleasant day is in store for Saturday with mostly sunny to partly
cloudy skies and highs in the upper 60s to mid 70s. Winds will be
light and variable Saturday morning, becoming more westerly by the
afternoon
&&
.LONG TERM...
(Sunday through next Thursday)
Issued at 313 PM CST Fri Jan 5 2024
Key Messages:
- Strong to severe thunderstorms possible Monday, mainly over the
Victoria Crossroads.
- Freezing temperatures possible Tuesday night.
- Windy Tuesday behind a strong cold front.
- Elevated to Critical fire weather danger possible Monday and
Tuesday.
The long term forecast remains on track with the previous packages.
After a quiet weekend, the weather pattern will become fairly
progressive. A slug of moisture will be in place Monday, with PWATs
around 1", ahead of a strong cold front so there is some potential
for convection along the front. While the majority of the support for
severe weather will remain just to the northeast of our area, SPC
has placed the Victoria Crossroads in a Slight Chance for Severe
Weather as CAPE values around 1300 J/kg bleed into the area. With a
strong 40-50 knot 850 mb jet over the area, winds will mix down,
with a 40-60% chance of 40 mph wind gusts. A Wind Advisory may be
necessary for Monday and Tuesday. These strong winds and dry
conditions will also lead to Elevated to Critical fire weather
concerns Monday night and Tuesday.
Cold air will pour into the area Tuesday. Most locations will remain
in the mid to upper 30s, with those in low-lying drainage areas the
most likely to experience freezing temperatures. There is still some
question how cold we will actually get, with the ECMWF indicating
much colder (~3 degrees) 850mb temperatures than the GFS. If the
ECMWF is correct, we could see more areas nearing freezing for
Tuesday night.
With dry air and strong winds developing behind the cold front,
elevated to critical fire weather is expected, mainly across the
Brush Country.
&&
.AVIATION...
(00Z TAFS)
Issued at 542 PM CST Fri Jan 5 2024
VFR conditions will generally prevail through the TAF cycle at
most terminals under clear to mostly clear skies. The only
exception is for a brief period between 09-13Z Saturday morning
for patchy fog development. However, models have begun to cut back
on such possibility as dewpoint depressions seem to remain wide.
For now though, will continue to carry this mention on a TEMPO
MVFR group until better agreement is reached. Otherwise, expect
light and variable winds through the end of the cycle.
&&
.MARINE...
Issued at 313 PM CST Fri Jan 5 2024
Winds and seas across the offshore waters have dropped below
advisory levels and the Small Craft Advisory has been allowed to
expire. However, conditions across the offshore waters remain at
moderate levels this afternoon and mariners with small craft
should exercise caution. Seas may occasionally reach 7 feet and
winds may briefly be around 20 knots through the remainder of this
afternoon. Otherwise, northwest winds will continue to decrease
becoming light across the bays and coastal waters by this evening.
Light offshore winds can be expected Saturday and Saturday night.
Winds will increase to moderate to strong ahead of a cold front
on Monday. Isolated to scattered showers and thunderstorms are
expected Monday and Monday night. The front will move across the
waters Monday night and Tuesday, with strong to very strong flow
developing in its wake. Frequent gusts to gale force are likely
(60-80%) Monday night and Tuesday. Winds will become light and
onshore flow returns Tuesday night.
&&
.PRELIMINARY POINT TEMPS/POPS...
Corpus Christi 43 71 45 70 / 0 0 0 0
Victoria 40 69 40 65 / 0 0 0 0
Laredo 43 72 44 71 / 0 0 0 0
Alice 42 74 42 72 / 0 0 0 0
Rockport 47 69 48 69 / 0 0 0 0
Cotulla 38 74 40 72 / 0 0 0 0
Kingsville 42 71 43 71 / 0 0 0 0
Navy Corpus 49 69 53 70 / 0 0 0 0
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...None.
GM...None.
&&
$$
SHORT TERM...TE
LONG TERM....LS
AVIATION...ANM/88
Area Forecast Discussion
National Weather Service Dodge City KS
538 PM CST Fri Jan 5 2024
...Updated Aviation Discussions...
.KEY MESSAGES...
- Storm #1 snowfall of 2 to 4 inches across much of southwest,
west central, and southwest Kansas will have some impact on
warmup both Saturday and Sunday along with cloud cover.
- Dangerous blizzard conditions are now likely (greater than 50%
chance of occurrence) across much of our southwest Kansas
region.
- Onset of dangerous winter conditions from mid-morning Monday
out west along Highway 83 to early afternoon around Dodge City
to late afternoon across Highway 183 corridor.
- Widespread accumulating snow of 3" or more likely (greater
than 70%) with widespread frequent wind gusts 50+ mph during
the height of the storm leading to dangerous blizzard
conditions focused on Monday afternoon through early Tuesday
morning.
&&
.SHORT TERM /THROUGH SATURDAY/...
Issued at 340 PM CST Fri Jan 5 2024
Storm #1 was exiting the western half of Kansas this afternoon, but
abundant low cloud continued, keeping temperatures right around 32
degrees this afternoon. Low clouds will continue through most of the
night east of Highway 83, but there will be a gradual erosion of the
low cloud with a greater erosion of cloud toward daybreak as
stronger northwest winds kick in. The HRRR is showing 1/4 mile
visibility in fog later this evening, but the light westerly
component wind does not favor fog development, and even if fog does
develop, it will likely not last more than a few hours until the
stronger downslope winds kick in.
Over this weekend, weather will be fairly tranquil in between
storms. Even though the low cloud will dissipate early in the
morning, higher level cloud will move in from the west, so full sun
is not likely until perhaps mid to late afternoon to aid in a more
robust snow melt. High temperatures have been lowered a couple
degrees to the upper 30s most locations given the rather large areal
extent of 2-4" new snow cover.
On Sunday, as Storm #2 begins to take shape across the Southwest,
thicker mid and high level cloud will move in, and this will limit a
warmup along with any remnant snow cover. Regardless, we should be
able to lose most of the rest of Storm #1`s snowpack before the next
storm moves in Monday.
&&
.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
Issued at 340 PM CST Fri Jan 5 2024
Major winter storm system will impact our southwest Kansas region
Monday and Monday Night. The GFS and ECMWF, along with their
associated ensemble systems continue to put southwest Kansas in the
crosshairs for potentially major impacts from blizzard conditions.
The mid level (500mb) cyclone will close off across north central
New Mexico very early Monday morning and continue to strengthen from
a 536dm low at 12Z to around a 531dm low at 00Z Tuesday as the
cyclone center travels almost due east from northern New Mexico,
across the Texas Panhandle and into west central/northwest Oklahoma.
This will support robust 700-850mb development across the Texas
Panhandle as well with a 700mb low midday somewhere near the Texas-
Oklahoma Panhandle border. Almost all the models are showing a very
impressive blossoming of precipitation in the 12-18Z time frame
Monday, just as low level cold advection begins to develop. A
southwest-to-northeast oriented front will move east in earnest by
midday 18Z and any liquid precipitation will rapidly change to snow,
surface temperatures falling through the upper 20s, and north winds
rapidly increasing to 25 to 35 mph sustained. By afternoon, wind
gusts from the north will continue to increase to 45 to 55 mph to go
along with snowfall rates of 1/2 to perhaps 1" or even greater at
times. This dangerous combination of weather elements will almost
assuredly lead to blizzard conditions with widespread whiteout
or at the very least near-whiteout conditions over open areas
outside of towns/cities of southwest Kansas.
It cannot be stressed enough how dangerous it will likely be across
much of southwest Kansas by Monday afternoon, especially along and
between the Highway 83 and Highway 283 corridors from Oklahoma
border north to Interstate 70. The dangerous combination of frequent
wind gusts 45 to 60 mph, moderate to heavy snow, and temperatures
falling into the 20s will likely continue through the mid evening
hours. Latest models keep the intense 850-700mb gradient across
southwest Kansas through at least sunrise Tuesday morning. Sustained
winds are expected to finally settle down by mid morning Tuesday,
which will help visibility improve.
As far as total snowfall goes, there is roughly a 50% chance of
total snowfall in the range of 2 to 8" across much of southwest
Kansas. It is increasingly likely that 6-9 inch snow will fall
in a southwest to northeast band somewhere, but this will
probably only occur in a roughly 30-mile wide band with
gradually lower amounts on either side of this greatest snowfall
axis. Regardless, given these wind speeds, blizzard conditions
are likely with even 2" of new snowfall. For all the above
reasoning, we have issued a Winter Storm Watch pretty early
given the increased probability of Blizzard Criteria being met,
which requires at a minimum 3-hr duration of visibility
frequently below 1/4 mile in considerable blowing/drifting snow
from 35 mph sustained wind or in frequent gusts.
Please keep checking back regarding the updated timing of when the
dangerous conditions will develop for your specific location,
because the weather will likely be considerably different during the
day Monday from west to east across the front and change rapidly
once the north winds pick up and the temperature drops below 32
degrees.
&&
.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 516 PM CST Fri Jan 5 2024
Focus on the 00z TAFS will be on low ceilings and areas of fog
between 00z and 12z Saturday. CAMS remain in good agreement
with abundant low level moisture being present over southwest
Kansas overnight as light west/northwest winds develop. The
westerly wind direction does not typically favor fog capable of
reducing visibility to less than 1 mile but given how light the
winds are forecast to be for several hours and high boundary
layer moisture am currently leaning towards the latest CAMS
with a 2-4hour window of low visibilities due to fog overnight.
Confidence for the LIFR (<1 mile) visibility overnight is
30-50% with the best timing for this to occur between 03z and
09z Sat. There is a +80% chance for ceilings to be in the IFR
category overnight with a 40-60% chance for LIFR. Ceilings will
improve Saturday morning as wind speeds increase to around 15
knots between 15z and 18z Saturday.
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
Winter Storm Watch from Monday morning through late Monday
night for KSZ030-031-043>046-061>064-074>078-084>087.
&&
$$
SHORT TERM...Umscheid
LONG TERM...Umscheid
AVIATION...Burgert
Area Forecast Discussion
National Weather Service Green Bay WI
556 PM CST Fri Jan 5 2024
Updated aviation portion for 00Z TAF issuance
.KEY MESSAGES...
- The weather pattern will be conducive for several wintry systems
to impact the region over the next week.
- Probabilities for greater than 1 inch and 2 inches of snow have
expanded south to areas north of a Merrill to Kewaunee line
from tonight into Saturday night. In general, a 1 to 3 inch
snowfall is possible north of a Merrill to Manitowoc line.
- Potential for significant snow on Tue/Wed has decreased.
However, the best chance for over an inch of snow will be
across east-central Wisconsin with another round of light snow
possible Wednesday night and Thursday.
- After a very mild start to winter over the last month, a pattern
shift could result in below normal temperatures by the middle of
the month.
&&
.DISCUSSION...
Issued at 223 PM CST Fri Jan 5 2024
Short Term...Tonight and Saturday
The latest RAP analysis and satellite/radar imagery show low
pressure centered over the south-central Plains and another weak
low over North Dakota. Modest warm advection is occurring ahead of
both systems leading to areas of freezing drizzle over northeast
Minnesota, northwest and north-central Wisconsin. Ceilings below
1000 ft along with visibilities below 5sm remain from Merrill to
Manitowish Waters. However, the southwest flow in the low levels
has be gradually pushing the low overcast northeast, with low
clouds scattering out at Marshfield and Wisconsin Rapids. A crude
approximation shows the low clouds scattering out over Vilas
county in the 4 pm - 6 pm time frame, which leaves little time for
freezing drizzle to become significant issue once the sun goes
down and prior to the snow developing. Think the best course of
action is to handle lingering freezing drizzle with an SPS.
Otherwise, returns seem to be expanding on area radars across
Minnesota and far western Wisconsin early this afternoon. This may
be occurring a little quicker than models indicate though have not
seen ground truth of precip reaching the ground. In general,
models indicate returns increasing further this afternoon to the
west with light snow moving into Vilas county around 6 pm. As the
low pressure systems move east or northeast, precip trends and
snowfall accumulations remain the primary forecast concerns.
Tonight...Low pressure systems will converge on Wisconsin by 6 am
Saturday. Increasing QG forcing and upper divergence in the left
front quad of a jet streak in combination with weak warm
advection will lead to precip continuing to expand across northern
Minnesota, the western Upper Peninsula and far northern Wisconsin
this evening. In general, precip amounts have diminished/shifted
north tonight with snowfall amounts indicating areas north of a
Rhinelander to Iron Mountain line having the highest potential for
greater than an inch. Precip will also start to expand over
northeast WI and particularly near the lake shore late tonight where
winds will be backing to the southeast direction and bring in
enhanced precip off the Lake. While delta T`s are rather marginal
(11-12C), a couple of the higher resolution models develop upwards
of a half inch of snow for the lakeshore by 6 am Saturday.
Finally, increased low temps due to south winds and cloud cover.
Saturday...Shortwave energy and a weakening surface trough will
slowly move across the region. Southeast/onshore flow will
continue for much of the day as delta T`s increase to 12-13C,
which is sufficient for lake enhancement. The higher resolution
models are also indicating increased low level convergence across
the Door Peninsula and into far northeast WI from early in the
morning through about mid-afternoon that could create locally
higher precip rates. Due to this convergence, qpf and snow amounts
have increased across northeast Wisconsin, resulting in forecast
accumulations of 1-2 inches across much of northeast WI.
The 24 hours snowfall forecast has increased across parts of
north-central WI, most of northeast WI and into the Fox Valley.
This looks like a relatively long duration, light snow event with
snowfall amounts failing to reach 3 inches in a 12 hour time span.
Given the snow will also be falling on a weekend, will refrain
from issuing an advisory.
Long Term...Saturday Night Through Friday
An active pattern expected with several systems moving across the
middle of country over the next week. Also, a big pattern shift
is expected by the middle of the month with a return of below
normal temps which is a complete reversal from the record warmth
of the last month.
For Saturday night, light snow will linger across much of the area
into the evening. Forecaster confidence in snowfall amounts are
lowest along the Lake Michigan shoreline. Low level winds coming
off the relatively warmer waters of Lake Michigan and lake to
850mb temperature differences around 12C will result in some lake
enhancement in this region. However, some of the meso models are
depicting a lake ban setting up across Kewaunee and southern Door
counties which could boost snowfall totals considerably higher
than what is currently forecast. Later shifts will need to monitor
this area to see if these lake bands materialize. Overnight Saturday
night, light snow along a frontal boundary will move into north-
central Wisconsin which could bring light snowfall amounts to this
region. The light snow will linger into Sunday morning across the
north.
Otherwise, tranquil conditions are expected Sunday afternoon through
Monday afternoon. The first system is expected to move across the
region Monday night into Tuesday evening. There is still a lot of
uncertainty in snowfall amounts with the system across northeast
Wisconsin. The ECMWf could have 2 to 4 inches over Kewaunee, Calumet
and Manitowoc counties with lighter amounts to the north. Several
other models were showing under an inch. Since this system is still
several days out, will continue to monitor to see where this system
ends up.
A potent clipper system will move across the region Wednesday night
and Thursday. The latest model trends today would suggest several
inches of snow are possible with this system. The models will
likely jump around with the track of the system so snowfall amounts
will vary in the coming days. Another system will pass south of the
area on Friday into Friday night bringing a small chance of light
snow. Looking towards the middle of the month, arctic air across
Canada will slide southward into the northern United States, bringing
some of the coldest air of the season by the 15th. That is not saying
much as Green Bay, Rhinelander and Wausau haven`t fallen below
zero so far this winter. That is how mild it has been.
&&
.AVIATION...for 00Z TAF Issuance
Issued at 537 PM CST Fri Jan 5 2024
The weather system that will impact the region over the next 24
hours appears to be disorganized and has saturation issues, so
it will be difficult to forecast precise start/end times for the
precipitation, and low cloud trends tonight.
Flight conditions have improved to VFR along and south of a line
from roughly TKV-GRB-MTW, but MVFR conditions remained over far NE
WI, and IFR was observed in far NC WI. Minor VSBY restrictions in
Vilas County hinted at a possibility of localized light freezing
drizzle.
Light snow is expected to develop over far north-central WI this
evening before gradually spreading across the rest of the region
late tonight into Saturday morning. After a period of VFR
ceilings this evening, flight conditions will deteriorate again
to MVFR/IFR as the snow develops. Plowing operations may be needed
north of a TKV-AIG-EZS-GRB-MTW line, where 1 to 2 inches of snow
could accumulate by midday Saturday, with nearly 3 inches possible
near the Upper Peninsula border. Under an inch of snow is
expected elsewhere.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
DISCUSSION.....MPC/Eckberg
AVIATION.......Kieckbusch
Area Forecast Discussion
National Weather Service Louisville KY
808 PM EST Fri Jan 5 2024
.Forecast Update...
Issued at 800 PM EST Fri Jan 5 2024
A complicated forecast, with, not surprisingly, the Ohio Valley
being in a zone dealing with competing warm air advection and wet-
bulb cooling. The past several days, models have pegged the zone
east of I-65 and roughly along and north of I-64 as the target for a
quick transition from rain to snow in the early morning hours
Saturday before the deeper moisture lifts out and we`re left with
just low clouds and mist by mid morning.
So the easy part is saying yes, it will precipitate overnight. Now,
to assess how models are handling the competition. Latest ACARS
sounding from Louisville shows the saturated layer coming down from
above at around 600 mb. This is roughly on schedule with the RH
fields from the NAM/RAP, though a little ahead of schedule with the
HRRR. It also shows temps around 850 mb are right at 0C, which all
three models are handling fairly well. As you progress forward to
06Z, you can see wet bulb effects initially cool down the column but
then temperatures flat line or even rise. All three of those models
show this.
Another feature to watch for that could cool a localized area down
is seeing some hints at narrow banded features developing. These
could briefly punch through that warm air with the heavier rates and
allow some snow to make it to the surface.
Given the above factors, think the southern side of our advisory
area has the best chance to see those banded features and the
northern side may actually stay more as rain. KY Mesonet
temperatures over the northern Bluegrass have dropped off quickly
despite cloud cover this evening. With surface winds forecast to
remain easterly, not expecting too much of a warm up, so cannot rule
out briefly heavier rates dropping some snow there either. Ongoing
placement of Winter Weather Advisory thus looks reasonable, and
Special Weather Statement outside of that Advisory would cover
localized up to 1" amounts.
&&
.Short Term...(This evening through Saturday)
Issued at 325 PM EST Fri Jan 5 2024
=====================================================================
Key Messages...
- System moves through the region late tonight through midday
Saturday, mixed precipitation types likely along and north of the I-
64 corridor.
- Slushy snowfall accumulations of up to 1 inch expected in
portions of north central KY and southern IN (east of I-65). Locally
heavier totals possible, but low confidence in location.
=====================================================================
Dry conditions are present across the region this afternoon as upper
level ridging continues to hold on across the southeastern CONUS. To
the west, troughing over the central Plains is mutually amplifying
with a developing area of sfc low pressure over the northwestern
Gulf of Mexico. Temperatures across central KY and southern IN are
fairly seasonable this afternoon, with readings ranging from around
40 degrees in the north to the upper 40s across south central KY.
Tonight, the system over the northwestern Gulf will lift northeast
through MS/AL into the lower Tennessee Valley. Moisture advection
ahead of the system will saturate the column from top-down, with
moist isentropic lifting leading to the development of light
precipitation after midnight tonight. At precipitation onset, p-type
is expected to be mainly rain, though a brief period of sleet cannot
be ruled out as the column saturates.
The challenge in the forecast late tonight into tomorrow morning is
that there are competing factors which will play a substantial role
in precipitation type. Because there is no readily-available supply
of cold air with this system, most if not all model soundings show
the near-sfc layer (up to around 1 km) being at or just above
freezing. Combine this with low-level warm advection ahead of the
system, and you have a couple factors detrimental to frozen p-types.
On the other hand, several short range models (12Z NAM is a good
example) show good mid-level frontogenesis across SE Kentucky early
tomorrow morning. Additionally, the KY Bluegrass region will be
positioned within the cyclonic downshear region (left exit) of the
mid-level jet axis. These two factors would support the development
of heavier mesoscale precipitation bands, which would lead to
downward transport of colder air aloft. With enough near-surface
cooling, as shown in the HRRR and some other high-res progs, rain
should change to snow in spite of marginal sfc temperatures.
Where these heavier snowfall rates occur, a quick accumulation of
wet snow would be expected. The most consistent signal (and
therefore the highest confidence) in snowfall accumulations has been
over the KY Bluegrass, where you get the greatest assistance from
dynamic support, while also not being so far south that warm
advection overwhelms everything. Where there is highest confidence
in light snow accumulating to around 1 inch tomorrow morning, have
gone ahead with a winter weather advisory. Could certainly see the
advisory being expanded south and west if subsequent hi-res guidance
and obs continue to support accumulating snow along and south of the
I-64/I-75 corridor.
By mid-morning Saturday, precipitation will pull out of the region
as the sfc low quickly pushes off to the west. Modest low-level cold
advection and trapped near-sfc moisture should keep a broad low
stratus deck in place through the day on Saturday, resulting in a
cool and gray day tomorrow. Highs on Saturday will struggle into the
upper 30s and lower 40s.
.Long Term...(Saturday night through Friday)
Issued at 225 PM EST Fri Jan 5 2024
=============================================================
Key Messages:
* Wet & Gusty Storm System Likely Tuesday
===========================================================
A weak upper level wave/trough will pass through the region Saturday
night into Sunday and bring with it some light precipitation. Model
ensemble thermal profiles generally suggest rain, with only a very
small percentage (<5%) hinting at any sort of light snow
accumulation potential. Surface temps will generally be above
freezing Saturday night into Sunday, so in the off-chance that snow
does occur, the relative light nature of it combined with warm low-
levels will make it non-impactful.
Upper level ridging builds in from the west late Sunday into Monday
and high pressure will settle over the eastern CONUS, setting up
southerly to southeasterly return flow over the Tennessee and Ohio
Valleys. This should help to bump up high temps into the upper 40s
and low 50s Monday.
A fairly significant and compact upper level trough will then swing
from the southern Plains into the Ohio/Tennessee Valleys Monday
night into Tuesday, bringing with it widespread precipitation and
gusty conditions. Majority of model guidance ensembles (>90%) keep
precipitation as all rain at onset Monday night, but if the
trough/surface low takes a more southerly track, we could see wintry
precip to briefly start things off before transitioning to a cold
rain. The bigger story will be the gusty winds. EPS probabilities
for +40mph peak wind gusts on Tuesday are as high as 90% across
southern and eastern Kentucky, with 20% to +30% chances for +50mph
peak wind gusts within the same areas. Precipitation may also end as
snow on the backside of the system with minor accumulations possible.
Our system will likely lift out of the region by Wednesday with
drier conditions in its wake, though they may be short-lived as yet
another system takes aim at the region late Thursday into Friday.
&&
.Aviation...(00Z TAF Issuance)
Issued at 630 PM EST Fri Jan 5 2024
Potent storm system crossing the Midwest this hour will bring in a
surge of precipitation to the region in the next few hours. Cooling
temperatures aloft will compete with warmer southerly winds aloft to
make a transition area of rain/snow likely along/near the I-64
corridor starting around 8Z and continuing to daybreak. That
transition zone should push northward by mid morning, allowing for
all rain before the rains end and we`re left with just mist/low cigs
(very likely IFR) at least into the early afternoon hours. Another
wave coming in Saturday evening won`t have as much moisture to work
with, but could keep our low cigs around for beyond this TAF period.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...Winter Weather Advisory from 3 AM to 1 PM EST Saturday for
KYZ035>037-040>043-048-049.
IN...None.
&&
$$
Update...RJS
Short Term...CSG
Long Term...DM
Aviation...RJS