Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 01/24/21
Area Forecast Discussion
National Weather Service Caribou ME
923 PM EST Sat Jan 23 2021
.SYNOPSIS...
Low pressure will remain over the Maritimes into Monday. High
pressure will build into the area Tuesday into Wednesday. A
large storm system will pass south of the area Thursday.
&&
.NEAR TERM /THROUGH SUNDAY/...
9:23 PM Update: Satellite pictures continue to show a weather
disturbance moving out of the Gaspe Bay Peninsula and into
northern Maine. Area radars showing some weak returns across
northeast Aroostook County. The near term models have been
consistent on the idea that snow shower activity will increase
late this evening and especially after midnight across northern
and central Aroostook County. Until the snow showers start to
become better organized it remains a challenge as to the amount
of areal coverage and intensity. There is certainly the
potential that a few spots could pick up an inch or two of
flurry snow, while other areas remain nearly dry. The big
concern will be if any of the snow showers become more intense
and combine with the gusty wind in open areas and higher terrain
to produce a sharp reduction in visibility. Confidence is not
high enough to issue any special statements, but this will need
to be watched closely overnight.
Previous discussion:
clouds begin to return later tonight as another disturbance
swings down from Canada. The two runs of the HRRR along w/the
latest RAP and NAM show some snow breaking out n of the border
and then sliding s into northern Maine later tonight. A 40-45 kt
llvl jetstreak is forecast to dive across the region later
tonight aiding kicking off the snow. The highest percentages for
accumulating snow per the NAM NEST and HRRR is pointed to NW
and NE Aroostook w/up to an inch of snow, where the best
moisture convergence is forecast to be situated. Decided to go
w/light snow wording where percentages were at least 60%, and
snow showers w/percentages below 60%. Temps will cool off
through the evening before being capped by the clouds. Further s
across the Penobscot Valley and Downeast, less clouds initially
will allow for temps to drop off sharply. Given the llvl
jetstreak, winds will increase in the blyr overnight and w/the
colder temps in the forecast, wind chills will be going below
zero everywhere. The coldest wind chills will be across the
western areas as temps are expected to hit in the low single
numbers. Given that winds chills could reach AOB -20F in Nrn
Somerset County. After collaboration w/ GYX, decided to issue a
Wind Chill Advisory for that area from late tonight into Sunday
morning. Blowing snow expected through the night especially in
the open areas.
For Sunday, gusty NW winds of 15-20 mph w/higher gusts during the
day w/plenty of clouds across the northern 1/2 of the CWA
including the Maine Central Highlands. Less cloud cover further
due to a downsloping wind. This will need to be watched however
as the GFS/NAM soundings show moisture being trapped under a
warm layer developing aloft. The warming forecast to take place
as that warm layer takes hold. This will lead to light snow and
snow showers winding down by early afternoon. Temps during the
day will warm some but w/clouds around will be capped in the
upper teens and lower 20s across the CWA w/the exception of
western areas, as temps will run below normal. Blowing snow will
continue during the day.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
Fairly strong North Atlantic low pressure will be off the
Canadian Maritimes as a ridge axis begins pushing into Western
New England. Decent pressure gradient between the high and low
results in breezy northwest winds. Northwest flow with moisture
being advected in aloft from the north around the large low we
can expect stratus or stratocu in place. As we have seen
recently just enough moisture aloft getting squeeze out we will
likely see flurries and snow showers across the St. John Valley
into the North Woods. Despite the winds, partly to mostly cloudy
skies across the north the cold air advection will push
temperatures down into the single digits to teens.
Monday starts out generally clear south & east of the Longfellow
Mtns and I-95. Flurries and snow showers across the far North
with mostly dry and cold breeze south. During the day the FA
stays split with sunshine across the Highlands to the Downeast
coast. Partly sunny to perhaps overcast at times across northern
areas thanks to the increased moisture aloft north of the
elongated vorticity max overhead. Snow showers should be limited
to far Northwest areas with potential streamers coming off the
St. Lawrence else where a quiet weather day. Tuesday stays quiet
as well as high pressure pushes into Western Maine with mostly
dryer air aloft with the exception across far Northern areas.
Later in the day 850-700mb winds shift northeast and moisture is
advected in from the Canadian Maritimes in response to a
developing storm system over the Mid Atlantic states. This shift
in the winds will cause clouds to increase during the daytime.
Mostly sunny across the southern half of the CWA with partly
sunny skies across the northern half.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
Upper level low will be shifting out over the North Atlantic
from the Canadian Maritimes keeping the heart of the split 500mb
jet overhead. Aloft at 700mb & 850mb the flow is generally from
the north & northeast which means we wont see any true arctic
air. Will it be cold? Yes, still cold but it will be above
average throughout the period. Wednesday ridging axis off to our
west with generally weak north-northwest flow there will be
moisture at the mid-levels so expect a partly sunny day.
Temperatures in the upper 20s to mid 30s from north to south.
Thursday we will be well north of a rapidly developing storm
system off the Mid-Atlantic coast. Generally a light northeast
flow with partly to mostly sunny skies given the ridging at
500mb just to our west over Vermont & Quebec. Thursday night and
Friday model guidance is in pretty decent agreement that the
moisture from a large Nor`easter will stay south of the FA.
However, it is possible there may be some snow showers on the
far fringe reaching the Downeast coast & islands. It is a
possibility but not confident it occurs based on latest ECMWF &
GFS solutions with the best chance being just increasing
clouds. Friday took a blend of guidance with generally a ridging
axis building in behind the departing storm system. The GFS
operational run is hinting at a sharp vorticity max associated
with a 500mb shortwave. This feature may pose at most the
potential for increased cloud cover across the north but very
little moisture to work with so we should stay dry.
Generally partly cloudy skies Saturday morning with light winds
so another morning with lows in the single digits north, teens
in the south. 12z operational suite consistent with bringing the
ridging into the FA but north flow with increased moisture
aloft suggests a partly sunny day. Temperatures look to be near
or slightly above average by next weekend.
&&
.AVIATION /01Z SUNDAY THROUGH THURSDAY/...
NEAR TERM:
Tonight...VFR/MVFR for the northern terminals becoming MVFR with
local IFR at times in snow showers overnight. VFR for KBGR and
KBHB. NW winds 10-15 kt w/gusts 25+ kt. LLWS for northern
terminals later tonight.
Sunday...MVFR early for northern terminals becoming VFR. KBGR
and KBHB will stay VFR. NW winds 10-15 kt w/gusts to 30 kt. LLWS
for the northern terminals.
SHORT TERM:
Sun Night... MVFR clgs North becoming VFR. VFR elsewhere.Slight
chance of snow showers at FVE & CAR. NW winds 5-15 kts at all
sites with perhaps a few gusts to 25 kts at BHB.
Mon... VFR. MVFR clgs possible in the afternoon at FVE. NW winds
5-15 kts.
Mon Night... MVFR clgs at FVE, CAR, PQI. VFR elsewhere. NW
winds 5-15 kts.
Tue... VFR. MVFR clgs possible at FVE, CAR, PQI at times. NW
winds becoming N during the day 5-10kts.
Wed... VFR. MVFR clgs possible at FVE, CAR at times. N winds
5-10 kts.
Thu... VFR. N winds 5-15 kts.
&&
.MARINE...
NEAR TERM: Gale Warning remains in place through Sunday. NW
wind now gusting to gale force at the eastern Maine Shelf as of
9 pm with gusts to 40 kt overnight and into Sun. Seas attm were
around 4-5 ft,but are expected to build 5-7 ft later tonight
into Sun. Freezing Spray Advisory in place through Sun morning
for moderate freezing spray.
SHORT TERM: Gales will drop to SCA winds and seas Sun night. Mon
morning SCA waves will fall below SCA levels. Winds will remain
at SCA levels through Tue morning. Then falling below SCA
through Tue night before going back to SCA overnight into Wed.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...Wind Chill Advisory from midnight tonight to 7 AM EST Sunday
for MEZ003.
MARINE...Freezing Spray Advisory from midnight tonight to 7 AM EST
Sunday for ANZ050>052.
Gale Warning until 7 PM EST Sunday for ANZ050>052.
&&
$$
Near Term...CB/Hewitt
Short Term...Sinko
Long Term...Sinko
Aviation...CB/Hewitt/Sinko
Marine...CB/Hewitt/Sinko
Area Forecast Discussion
National Weather Service Cheyenne WY
759 PM MST Sat Jan 23 2021
.UPDATE...
Issued at 751 PM MST Sat Jan 23 2021
Light to occasionally moderate snow ongoing late this evening
across southeast Wyoming and portions of western Nebraska. A weak
deformation zone has remained across south central Wyoming and
will likely be slow to dissipate tonight. Will keep the current
Winter Weather Advisories and Winter Storm Warnings going through
midnight, especially since the mountain zones have hit criteria
with 12 to 15 inches of snow estimated across the Snowy and Sierra
Madre Range. Recent reports out of central Carbon County are
around 5 inches to almost 6, so pretty sure criteria will be met
or come close enough over the next 6 hours. Lowered tonight`s
temperatures a few degrees, especially in areas that may see some
clearing by early Sunday morning. Added some fog to the lower
valleys and also to the southern Laramie Range as winds shift into
the south/southeast by sunrise. Updates have been sent.
&&
.SHORT TERM...(This evening through Tuesday)
Issued at 150 PM MST Sat Jan 23 2021
Forecast concerns deal primarily with ongoing snow event and snow
totals through Sunday morning.
Currently...Frontal boundary lays along the I-80 Corridor from
Cheyenne to Rawlins to Evanston this afternoon. Widespread area of
clouds seen on IR imagery moving across Carbon County at this
time in an area of strong isentropic upglide at the 295 and 300K
isentropic surfaces. Had heavy snow earlier across Rawlins with
ASOS reporting M1/4SM on their observation. Did have a report of 5
inches from our spotter out west of Rawlins earlier...but have
not heard anything from her in the past two hours or so. Webcams
showing snow from Arlington west to Rawlins. Looking at road
surfaces...snow does not look to be sticking to the roads out that
way at this time. Snow is sticking on I-25 up by Douglas however
as a band of snow moves through southern Converse County at this
time.
Going to let the current headlines run through the evening hours.
Both the HRRR and Hires NMM continue to show a band of moderate
to heavy snow along the front this evening across central and
northern Carbon County around 00Z that runs through 06Z...so with
5 inches already reported at Rawlins...confidence is high that the
warning will still verify this evening.
Was some concern for snow squalls this afternoon. Looking at the
NAM Snow Squall Parameters...we do see around 1.5 units along I-80
near Laramie through 00Z. But then it really tapers off
afterwards. Will continue to monitor webcams and radar and will
pass off to the evening shift when they arrive.
Snow really tapers off after 06Z tonight on mesoscale guidance. We
may be able to cancel the headlines after that time and will defer
to the evening shift for that.
Monday looks dry and cold with 700mb temperatures around -10C. 20s
and low 30s for highs across the CWA. We do see another chance for
snow Tuesday as another southwestern shortwave tracks across
central Colorado. This system looks to impact areas east of the
Laramie Range into the Panhandle with upslope flow. QPF forecasts
are on the low side...so significant snow accumulations are not
expected with this next system.
.LONG TERM...(Tuesday night through Saturday)
Issued at 150 PM MST Sat Jan 23 2021
Wednesday...Ridging aloft will help produce a warmer day with
maximum temperatures from the mid 20s to near 40 degrees at lower
elevations.
Thursday...The warming trend continues as the flow aloft turns
westerly with rising heights and thicknesses helping maximum
temperatures to climb into the mid 30s to near 50 degrees at lower
elevations.
Friday...Relatively mild and windy weather prevails as the southwest
flow aloft strengthens with surface lee troughing developing.
Saturday...With a trough aloft and its associated cold front moving
across our region, temperatures will be somewhat cooler with periods
of variable cloud cover. With limited lift and moisture,
precipitation chances look rather meager.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday afternoon)
Issued at 413 PM MST Sat Jan 23 2021
Widespread MVFR cigs and visibilities over the terminals this
evening due to low clouds and areas of mainly light snow, with
periods of IFR conditions in heavier bands of snow. Conditions
expected to improve west to east late evening and overnight with
VFR at all terminals by late Sunday morning.
&&
.FIRE WEATHER...
Issued at 150 PM MST Sat Jan 23 2021
Minimal fire weather concerns as the area stays in cold
temperatures through at least Tuesday before any warming takes
place. Many locations across southeast Wyoming...along and west of
the Laramie Range have seen snow accumulations as well. High
pressure builds back into southeast Wyoming Wednesday with
increasing temperatures and winds. Forecast still calls for non-
critical afternoon humidity with these increasing winds and
temperatures though...so no critical fire weather conditions
continue through the week.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...Winter Weather Advisory until 5 AM MST Sunday for WYZ101>103-
105>107-110-111-113.
Winter Storm Warning until 5 AM MST Sunday for WYZ104-109-112-
114.
NE...None.
&&
$$
UPDATE...TJT
SHORT TERM...GCC
LONG TERM...RUBIN
AVIATION...RE
FIRE WEATHER...GCC
Area Forecast Discussion
National Weather Service Des Moines IA
539 PM CST Sat Jan 23 2021
.DISCUSSION.../Tonight through Saturday/
Issued at 303 PM CST Sat Jan 23 2021
Forecast highlights:
-Snow and FZDZ tonight
-Moderate to heavy snow central to southern Iowa on Monday
-Possibly another light snow event Wednesday
Tonight into Sunday...weak isentropic lift along the 285K to 300K
surfaces with subtle moisture transport and just enough omega
within the snow growth region to continue the light snow over
northern Iowa this afternoon and into the evening. A secondary
round a snow is likely along some mid-level WAA ahead of a surface
low tracking across Nebraska. This is a bit further south per the
latest hi-res models and they suggest a band to develop over
west-central Iowa. The band looks to push east-northeast through
the evening hours and the latest few runs of the HRRR have been
consistent with the location and intensity along the western
portions of the CWA, including the I-80 corridor, to move in by
around 00z. Could see 2-3 hours of 0.5" to 1.0" snowfall rates
before 06z tonight and would be intense enough to cause some
travel issues along the Interstate 80 corridor west of the DSM
Metro. May need to expand the Winter Weather Advisory further
south if solutions continue this way. Late tonight, the deep
moisture moves east and ice introduction is lost along and south
of Highway 30 to the Missouri border overnight. Low level moisture
remains and is deep to around 2-3km and there is weak forcing to
cause areas of FZDZ overnight into Sunday morning. The
precipitation looks be over by 12z Sunday at the latest with a low
chance of some lingering light snow/FZDZ across the far eastern
edges through 14z.
Sunday night through Tuesday...Surface high pressure builds in
over much of MN and northern IA tomorrow night into Monday
providing a substantial amount of dry air into the state for the
incoming snow storm to contend with during the day Monday. 500mb
vort max and trough eject out of the southern Rockies and track
northeast through the Southern Plains Sunday night into Monday.
The low deepens as it moves northeast and by Monday afternoon the
surface low looks to be centered over eastern KS/western MO
(according to the 23.12z GFS). Surface pressure gradient tightens
as low the deepens to around 990mb by Monday afternoon and
northeast winds of 25 to 35 mph with some higher gusts possible at
times. This should really produce low visibility with the
moderate to heavy snow falling Monday afternoon into the evening
commute. As for the snow, the deformation zone sets up from
northeast KS through northern MO into south-central to southeast
portions of Iowa Monday afternoon. Along and south of the
Interstate 80, soundings becoming deeply saturated b/t 12-15z
Monday with a strong omega bullseye centered in the dendritic
layer over south-central to southeast Iowa. Forecast soundings
suggest a small warm layer b/t 900-850mb (1km) and looks to be
deep enough to cause some melting of the snow and thus have a
period of sleet going Monday morning across the far south. Before
12z Monday, there`s no ice introduction into the column but lift
present to cause some freezing drizzle before the deeper moisture
moves into southern Iowa after 12z.
Regardless of the FZDZ/PL potential, the forcing is strong enough
to produce very heavy snow and cool the column to below freezing
throughout its depth. Thus, intense snowfall rates at times are
likely Monday afternoon into the evening during the height of the
frontogenetical forcing and lift. This will really impact the
evening commute from DSM southward. Cross section from around
Denison to Columbia, MO, shows enough negative EPV for CSI release
and thus leading towards the potential for TSSN at times over
southern Iowa. Plus, the strongest frontogenetical forcing between
650-600mb, but evident in 750-700mb and 850-800mb, over southern
Iowa/northern Missouri, only helps the snowfall intensity. The
caveat with all of this is the surface high pressure to the north
providing the aforementioned dry air entrainment and leading to a
sharp gradient of heavy snow to just trace amounts. A sharp
gradient is likely even countywide and thus ranges are likely a
bit drastic but viable. The trend has been that the heaviest band
continues to shift northward over the past couple of model runs,
but only by a half of an Iowa county or so. Regardless, the DSM
metro and along Interstate 80 corridor looks to be the northern
edge of the heavier snowfall and thus included this area within
the Winter Storm Watch. The consistency of the heavy snow is
likely to be very sticky and could stick to powerlines and trees
leading to the potential for power outages with the strong winds
associated with the system.
Wednesday through Friday...another quick moving shortwave will
bring yet more snow to portions of Iowa on Wednesday. QPF amounts
are in the 0.10" to 0.15" range and with the latest 23.12z runs of
the ECMWF and GFS in good agreement on the QPF location, there is
an uptick in confidence with the snow potential on Wednesday.
Winds remain on the lighter side, 10-20 mph, but might be enough
to cause some blowing and visibility restrictions. Especially with
the fresh snow anticipated to receive on Monday.
&&
.AVIATION.../For the 00Z TAFS through 00Z Sunday evening/
Issued at 539 PM CST Sat Jan 23 2021
Main concern will be precip chances/type into prior to 18z...
then major storm south half within 36 hours. Wave crossing region
tonight with quick shot of MVFR/IFR cigs in -sn and lowering VSBY
to 1-3sm at times; aft 06z south sites mainly KDSM (through 14z)
and KOTM (through 17z) -fzdz expected. Minor ice accums expected.
Winds generally not an issue; cigs gradually rise by 21z
north/central. Major snow event Monday. /rev
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
Winter Storm Watch from Monday morning through late Monday night
for IAZ059>062-070>075-081>086-092>097.
Winter Weather Advisory until 6 AM CST Sunday for IAZ004>007-
015>017-023>028.
&&
$$
DISCUSSION...Podrazik
AVIATION...REV
Area Forecast Discussion
National Weather Service El Paso TX/Santa Teresa NM
435 PM MST Sat Jan 23 2021
.AVIATION...00Z TAF CYCLE
Winds will be the main issue for this cycle, but VFR conditions
are expected. For tonight, winds will gradually subside after
sunset with generally a SW direction favored and sustained speeds
under 10 knots. This will change mid to late afternoon (after 18z)
tomorrow as a cold front pushes west to east across the area.
Winds will increase sharply behind the front from the W to SW
(240-270) with sustained speeds of 20 to 25 knots and gusts over
30. SHRA and perhaps even SHSN will accompany the front with
highest chances toward DMN. At this time though, chances are too
low to include in the TAFs. With winds favoring the WSW, BLDU
cannot be ruled out though recent rains may mitigate this risk.
&&
34
.PREV DISCUSSION...200 PM MST Sat Jan 23 2021...
.SYNOPSIS...
Active weather is expected across southern New Mexico and west
Texas early next week as a series of upper disturbances with a
cold front move across the region. It will be windy on Sunday
with chances lowland rain showers and mountain snows. Monday
through Tuesday temperatures will become colder with widespread
snows continuing over the higher mountains while rain and
possible snow fall across much of the lower elevations. Over 8
inches of total snow are expected over portions of the Gila
Wilderness and Sacramento Mountains. Warmer dry weather is
forecasted for Thursday though Friday.
&&
.DISCUSSION...
.SHORT TERM...Tonight and Sunday...
Breezy winds largely subside tonight a few hours after sundown.
Seasonably warm temperatures expected tonight as cloud cover moves
into western areas. May even be an isolated snow shower after
midnight.
Bowling ball trough approaches during the day on Sunday as 80-90 kt
jet at 500 mb passes overhead. BL height consistency is an issue on
the NAM/GFS, which has an impact on wind speeds. GFS shows a swath
of low end advisory level winds from southern Dona Ana east into far
west TX and southern Otero county Sunday afternoon into the
overnight hrs. EURO shows breezy winds as well, but like NAM, not
advisory level. Thing is, could see some brief really strong winds
as front and associated upper trough move through, especially
LRU/ELP and east as just above sfc winds ramp up into the evening,
which would by default warrant an advisory. Still on the fence.
Regardless, it will be windy across the region Sunday.
The additional concern is precipitation Sunday, in the form of
lowland rain and mountain snow. Showers will develop early to midday
Sunday across western areas, then pick up in intensity Sunday
afternoon and into the evening. Best precip will be far western
areas, near the Divide, Gila, and the Sacs as well. Expecting most
of the accumulating snow across elevations above 7500 ft with 1 to 3
inches expected (collectively into Sunday night), but could see iso
higher amts on the highest peaks. Elsewhere will see rain showers or
perhaps mainly "white rain". The interesting part about this system
is there may be just enough instability juxtaposed with lift from
the upper trough and steep lapse rates for some rumbles of thunder.
NAM suggests this will be the case for most of the area, or a slight
chance anyway, whereas the extended HRRR paints more for western
areas. If a few more robust convective cells do develop, could be
strong wind gusts in the vicinity given the winds aloft. High
temps near 60 east and 50 west.
&&
35-DeLizio
.LONG TERM...Sunday Night through Saturday.
Strong upper trough will move across New Mexico and far west
Texas Sunday evening and should be east of the CWA by midnight.
Initially strong southwesterly flow ahead of system should
transport abundant moisture via Baja into the CWA with dynamic
forcing ahead of trough producing widespread precipitation. This
will occur while cold air advection continues behind Sunday`s cold
front resulting in below freezing temperatures with temperatures
falling to below freezing by sunrise Monday. However currently
believe most of the precipitation will end around midnight as
drier air flows into the region. Consequently snow will be mainly
limited to higher mountains with amounts mostly below 3 inches
above 7000 feet. Some of the lower elevations may receive a
dusting western zones.
Drying trend will be short lived as another deep upper level low
moves across southern California into Arizona Monday afternoon
with system showing only a very slow eastward drift across
northern Arizona through Tuesday afternoon. Slow approach of
system will place southern New Mexico and west Texas into a
prolonged period of increasing dynamic lift per differential PVA
fields. In addition models indicate mid level frontogenetic
forcing will be occurring much of this time. Moisture advection
will be modest but given the sustained lift precipitation will
spread west to east Monday and become widespread Monday night and
Tuesday, especially for locations west of the Rio Grande. Due to
both dynamic cooling and cold air advection snow levels will also
fall. Thus persistent snow expected upon the Gila Wilderness area
with total snow amounts up to 12 inches over a few locations by
sunrise Wednesday. Over 6 inches of snow also outlooked over the
Sacramento Mountains with several inches possible lower elevations
western zones where dynamics will be strongest.
A more westerly flow aloft develops Tuesday night as low
accelerates eastward across the Rockies and this should bring
rain/snow to an end. Snow amounts will therefore be mostly at or
below an inch lower elevations east of Rio Grande. However
continued easterly winds at low levels will sustain inflow of
Canadian air mass causing temperatures to remain well below
normal Wednesday. But as another deep upper trough approaches west
coast flow become more southwesterly resulting in a warming trend
Thursday and Friday. By Saturday this trough moves into the
southwestern United States possibly bringing more rain and
mountain snows to the area.
&&
05-Rogash
.AVIATION...Breezy SW winds through the afternoon, subsiding
shortly after sunset, ~01z, generally 10G20KTs with some higher
values. Precipitation and lowering CIGS begin to push into the
Continental Divide Sunday morning into midday with CIGS lowering
at KDMN and perhaps KTCS. Expecting terminals to remain dry
through around 18Z, then chance for showers after. VFR expected
however through this TAF cycle.
&&
35-Delizio
.FIRE WEATHER...
Quiet Saturday night, then storm approaches Sunday. Expect rain and
snow showers by the midday hours Sunday with the steadiest precip
Sunday afternoon into the overnight. Areas east will see light
precipitation in the form of rain, except for the Sacramento mtns. A
general 1 to 3 inches of snow expected Sunday into Sunday night for
high elevations over 7500 ft. Winds will be breezy to windy,
especially across the international Border and into far West TX.
Additionally, cannot rule out a rumble of thunder or two across
western areas Sunday afternoon. More breezy to winds conditions
Monday as the next storm system pushes into the Borderland. More
precip expected for mainly western areas and the Gila, with moderate
to heavy precip possible in the form of snow. Expecting a general 4
to 8, 6 to 12 inches across the Gila with 4 to 8 across the Sacs
with this system Monday through Tuesday night. Some snowfall
possible for the western lowlands as well including locations like
Deming and vicinity, could see a few stray snow showers elsewhere
farther east. This complex system pulls east by Wednesday leaving
cooler and drier conditions to end the week.
Ventilation Sunday through Tuesday generally very good to excellent
given the windy conditions and poor thereafter. Min RH`s >30 %
through Tuesday, decrease Wed-Thurs, but remain above critical
values generally.
&&
35-DeLizio
&&
&&
.PRELIMINARY POINT TEMPS/POPS...
El Paso 40 58 35 53 / 0 30 30 0
Sierra Blanca 38 60 31 51 / 0 20 30 0
Las Cruces 36 52 30 49 / 0 30 20 0
Alamogordo 38 55 27 49 / 0 40 40 0
Cloudcroft 24 35 15 27 / 0 50 50 10
Truth or Consequences 36 50 30 49 / 0 40 20 20
Silver City 32 42 27 38 / 0 80 60 70
Deming 33 51 27 49 / 0 40 30 10
Lordsburg 31 48 24 46 / 0 80 50 50
West El Paso Metro 42 57 35 53 / 0 30 30 0
Dell City 30 62 28 52 / 0 20 30 0
Fort Hancock 34 65 30 57 / 0 20 20 0
Loma Linda 36 53 30 46 / 0 30 30 0
Fabens 36 60 32 54 / 0 20 20 0
Santa Teresa 36 55 30 50 / 0 30 20 0
White Sands HQ 40 55 34 50 / 0 30 30 0
Jornada Range 30 52 27 48 / 0 30 30 0
Hatch 32 53 28 49 / 0 30 20 10
Columbus 36 53 31 50 / 0 30 30 0
Orogrande 38 56 29 50 / 0 30 30 0
Mayhill 32 48 23 39 / 0 50 50 10
Mescalero 25 45 19 36 / 0 50 50 10
Timberon 23 45 17 36 / 0 50 50 10
Winston 23 45 18 41 / 0 50 40 40
Hillsboro 29 49 24 46 / 0 50 30 30
Spaceport 31 51 25 47 / 0 30 20 10
Lake Roberts 21 40 21 37 / 20 80 60 70
Hurley 30 45 24 41 / 0 70 50 70
Cliff 29 46 28 43 / 20 80 60 70
Mule Creek 26 42 28 39 / 20 90 70 80
Faywood 33 45 26 42 / 0 60 50 50
Animas 32 50 26 47 / 0 70 50 50
Hachita 31 50 25 48 / 0 50 40 30
Antelope Wells 32 50 29 47 / 0 60 50 30
Cloverdale 34 41 30 39 / 0 80 50 60
&&
.EPZ WATCHES/WARNINGS/ADVISORIES...
NM...Wind Advisory from 1 PM Sunday to 6 AM MST Monday for NMZ411-413-
417.
TX...Wind Advisory from 1 PM Sunday to 6 AM MST Monday for TXZ418>424.
&&
$$
35/05/34
Area Forecast Discussion
National Weather Service Grand Rapids MI
700 PM EST Sat Jan 23 2021
LATEST UPDATE...
Aviation
.SYNOPSIS...
Issued at 327 PM EST Sat Jan 23 2021
- Light snow event Sunday
- Moderate snow event late Monday into Tuesday
- Seasonable mid week then warming toward weekend
&&
.DISCUSSION...(This evening through next Saturday)
Issued at 327 PM EST Sat Jan 23 2021
- Light snow event Sunday
Our next winter weather event is a 1 to 3 inch snowfall which
happens mostly during the mid morning hours of Sunday. The
greatest snowfall amounts will be between Route 20 and Route 10
with only limited amounts south of I-96.
This event is caused by a northern stream wave coming in phase
with a southern stream wave. We have coupling of the entrance
region of the northern stream jet with the exit region of a much
stronger southern stream jet. The area of enhanced lift from the
coupled jet feature crosses Lower Michigan during the mid morning
hours of Sunday. The mid level dynamics are strongest with the
northern stream wave. That creates weak isentropic ascent from the
northern part of southern jet (I-80) to the stronger dynamics
near Lake Superior during Sunday morning. The moisture for this
event is limited so the snowfall amounts will also be limited. The
bottom line through is greatest precipitation amounts will be
over the northern 1/3 of our CWA. Areas south of I-96 will see
very little snow tomorrow.
There is very good model agreement with this system. This
includes the hi-res models, the longer range models and the
ensembles from the SREF, ECMWF, GFS and Canadian. The hourly runs
of the HRRR and RAP model look very similar with this also.
Surface temperatures will be mostly near 30 during this event and
since it is during the day I see only limited impacts so it does
not seem we would need any sort of weather advisory for this snow
event.
- Moderate snow event late Monday into Tuesday
Our next system may turn out to give us one of our higher event
total snowfalls of the season to date. The event on the 29th into
the 30th of December brought 4 to 8 inches to this area. The event
on Tuesday seems to be one of those 4 to 6 inch events. However
the 12z run of the ECMWF has the heaviest snowfall farther north.
It is giving 8 to 12 inches between late Monday night and
Wednesday evening over central Lower Michigan. The axis of that
snowfall is along I-96 with the heaviest snowfall amounts over
western sections. However it is very important to note the ECMWF
has TWO storms. The one on Tuesday then the next on Wednesday. I
wrote about that second system yesterday, saying it looked to me
like that could get snow far north then the models at that point
suggested. We will have to watch this closely. We may be in a
position to make up some of our snowfall deficits.
What we have very complex interplay with a series of very closely
spaced Pacific systems. There lead system (the one that gives us
the Tuesday event) is currently over the Southwest CONUS. There is
yet another Pacific system just off shore of British Columbia that
will dig strongly south and shear the system over the SW CONUS out
into to Plains Monday. However there is a strong system currently
near the Dateline. That system is stronger than the two in front
of it. It is so strong it builds an significantly large upper
ridge over the SW CONUS by midweek. That allows the second system
to come out of the Southwest CONUS a little less sheared out at
upper levels. Thus the 300 mb close low is still together as it
crosses Michigan in Wednesday. If this happens we get two snow
events. It would snow Tuesday, then it would let up Tuesday night
only to redevelop Wednesday. Also if this does happen we will get
deeper cold air (850 temps would fall to near -15c) so some lake
effect snow will trail this system into Thursday.
One other point about all this is that what matters the most is
how much of a closed 700 to 500 mb circulation reaches Michigan.
This system (lead system) is shearing out, so it will weaken as it
moves eastward. Snowfall amounts will decrease from west to east
with this system no matter what too. If the system no longer has a
close mid-level circulation we get only a few inches of snow on
Tuesday.
The GFS does not bring the second system far enough north to give
us snow on Wednesday but I actually believe the ECMWF makes more
sense in doing what it shows on the 12z run. Time will tell but
for now we will not issue any headlines, this may change tomorrow.
- Seasonable mid week then warming toward weekend
Now we have to see how that third system develops and how the
upstream upper level ridge it builds moves east. It seems likely
it will be progressive since there are more Pacific shortwaves to
push that third one inland. At some point, surely by the weekend
we will get into deep southerly flow. Both the GFS and ECMWF do
agree on some sort of rain event with warm temperatures either
late in weekend or early in the following week but much colder
weather is likely to follow that.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 700 PM EST Sat Jan 23 2021
VFR conditions will continue much of the night, but after about
10Z light snow will begin overspreading the area from west to
east. Initially MVFR vsbys are expected but IFR vsbys will follow
a few hours after the snow starts.
The MKG, GRR and LAN terminals are more likely to have persistent
IFR Sunday 12Z-18Z, with less chance of IFR farther south at AZO,
BTL, and JXN. Expect moderate icing from the sfc to 17K ft while
the snow is impacting the area Sunday morning.
After 18Z Sunday the snow should diminish and move out, leading
to improvement in vsbys. However cigs will probably remain
predominately MVFR.
&&
.MARINE...
Issued at 327 PM EST Sat Jan 23 2021
It would seem our next system to bring marine headlines is the
Monday night into Tuesday system. That would be an east wind
through so the large waves would be on the west end of our Near
Shore. Likely we will end up with some sort of marine headlines
with this system but the east winds would mitigate much in the way
of shoreline wave issues.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
LM...None.
&&
$$
SYNOPSIS...WDM
DISCUSSION...WDM
AVIATION...Meade
MARINE...WDM