Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 02/20/22
Area Forecast Discussion
National Weather Service Gray ME
1032 PM EST Sat Feb 19 2022
.SYNOPSIS...
Snow showers will diminish overnight with gusty northwest winds
causing wind chills to fall below zero. High pressure builds in
Sunday, then shifts offshore Monday allowing temperatures to
climb above normal. A system will impact the region by mid-week
with the potential for rain for most of the area with mixed
precipitation possible for interior areas. High pressure will
build into the region from Canada on Thursday, followed by low
pressure passing off the New England coastline on Friday.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
1030PM Update: Snow showers continue to weaken south and east of
the mountains with only changes this hour being to match evening
temperature/dewpoint trends. Overnight lows look on track with
wind chills already below zero in the mountains...and in the
single digits to the south and east. Bundle up out there this
evening!
830PM Update: Band of SHSN along advancing arctic front has
remained coherent as it moves south and east...and have updated
the forecast for this over the next few hours as it brings a
wind shift along with another round of low vsbys. Expect
weakening of this band as it moves into the downslope regime
south of the Whites.
710PM Update: Remaining snow showers departing with a secondary
band noted south and east of KBTV which will make a run at the
CT Valley as it weakens moving south. Updated PoPs for current
radar presentation and matched up temperature trends /temps
needed to boosted a bit/. No other significant changes at this
time.
2030Z Update...
Have updated the forecast based on latest radar imagery and
mesoscale models. Snow showers and squalls will be reaching the
coastline within the next hour in Maine followed by falling
temperatures and low wind chills. Have adjusted pops this
package as well as winds and dew points.
Prev Disc...For the remainder of the late day and early evening
hours, roads temperatures continue to remain relatively steady
across the region. Pavement readings have remained mostly in the
30s across southern areas as cloud cover has thickened and
lowered with cooler readings further to the north. The warmest
layers are along and near the coastal plain and also over
southernmost New Hampshire. This has implications for the
potential for flash freezes across portions of the region as we
head into the evening hours. Cold pavement conditions continue
to the north.
Spoke with local fire departments earlier today for the status
of ice dams in New Hampshire. Reports indicate that most of the
activity has settled down for the time being with colder
temperature in place across the region, although rises have
occurred in the Conway area per gauged reports and fire
department reports. Will continue to closely monitor for
potential river rises or flooding however, especially along the
Sugar and Saco Rivers.
The latest HRRR and SPC analysis continues to do a very good job
depicting a line of snow squalls which were over central New York
State from the mid afternoon hours, albeit trends have been to
slow the timing of the line. Instability values and snow squall
parameters suggest this line will cross through the region
between 20Z-01Z from west to east, exiting the Midcoast region
early this evening. Low visibilities, gusty winds, dangerous
driving conditions and flash freezes may still occur.
Snowfall rates, visibilities and QPF have been increased through
this evening. Snowfall amounts could reach the 2 to 4 inch range
across the higher terrain in the north as this system crosses the
region.
Overnight, conditions settle down by the mid to late evening hours
with just some upslope snow showers in the favorable northwest
facing higher terrain. It will still be windy for a portion of the
night with GYX probability data plots indicating winds gusting to 25
kt. The same plots suggest a rapid decrease in the chance for
precipitation during the evening after the passage of the convective
snow shower and squall line. Temperatures bottom out in the single
numbers below zero in the north tonight and single numbers above in
the south. Winds will allow for wind chill values to drop to near 20
below zero in the north which is close to Wind Chill Advisory
Criteria.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
Much more quiet conditions expected on Sunday with the near normal
temperatures allowing for the threat of any ice jams to continue to
diminish with time. It will be mainly sunny over southern areas
where downslope conditions will persist. Mostly cloudy conditions
expected over northern areas where some moisture will enter the
region under an area of warm air advection over the periphery of the
ridge. Winds will diminish during the afternoon hours as the
strongest gradient shifts to the east.
A southwesterly flow then develops over the region as the large
ridge of high pressure exits off the Eastern Seaboard Sunday night.
Warm air advection over the region will allow for temperatures to
gradually rise during the overnight period which is reflected
in the non-diurnal trends.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
Monday, a weakening cold front will be advancing towards the
area from the NW. The cold front will carry little moisture, but
some snow showers will be possible across the western high
terrain. The more important variable will be cold air advection
associated with this front at the surface, as this could play a
role in precip types come Tuesday afternoon.
Monday night, the front attempts to continue across the eastern
CWA. This is visible from temp advection at the surface, but
the signal is more diluted in the low levels due to overrunning
SW WAA. This comes as the once separate jets begin to merge
across the southern Great Lakes. The GFS is strongest in keeping
this cold air anchored at the surface, plunging the front
through southern Maine. In addition, onshore warm air is also
weaker and presents a CAD situation as precip begins overunning
the area. This would result in a period of freezing rain inland
before joining southern NH and coastal ME with all rain Tues
evening/overnight. GEFS also displays a much weaker singular low
pres across the Northeast vs. EPS bringing a stronger sfc low
consensus through the eastern Great Lakes. As a result, ECMWF
and GEM solutions keep this cold front bottled up to the north
along the Quebec border, with a warmer rainy result outside of
the higher terrain. Have kept precip types locked to rain or
snow, but a mix may need to be mentioned in further forecasts if
confidence increases in a freezing rain solution, particularly
once NAM guidance is in range.
A non-diurnal temp trend continues Tuesday night into Wednesday
with rain overspreading the area. Low pressure will be tracking
NE, with enough lift out ahead to potentially bring some
enhanced precip rates. The more persistent stratiform precip
should move NE quickly w/ the low, as showers taper over the
area Wed and Wed night. With this warmup and potential rain
Monday through Wednesday, will again need to be wary of ice
movement amid runoff and snowmelt.
High pressure takes over Thursday and Thursday night, before
another disturbance approaches for Friday. A flatter, more
progressive track presents a chance for snow for much of the
area should the low stay to the south and track out to sea. Will
need to pay attention to positioning of a deformation band north
of the lows track, as well as any potential strengthening
over the GoME.
&&
.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
Short Term...
Summary: High pressure builds in through Sunday behind a
departing cold front before moving south of the region Sunday
night.
Restrictions: Last of the snow squall activity will impact AUG
and RKD through the next hour with brief LIFR/IFR VSBYS before
conditions return to VFR through Sunday night. The only other
exception to this will be some MVFR cloudiness this evening at
HIE.
Winds: Northwest winds 15g25kts will gradually subside after
midnight back to around 10kts before shifting southwest during
the day Sunday. Southwest winds will continue 5-10kts Sunday
night.
LLWS: No LLWS is expected through Sunday. Strengthening
southwest winds aloft Sunday night will bring the potential for
LLWS.
Snowfall rates / character: Snow at AUG/RKD will be briefly
heavy and not wet.
Long Term...VFR expected Monday outside of some MVFR at KHIE w/
-SHSN. Clouds thicken and lower late Mon night into Tuesday with
becoming IFR with snow changing to rain. SE winds increase and
become SW overnight into Wednesday. Conditions trend VFR
Wednesday evening with winds becoming W through Thursday.
&&
.MARINE...
Short Term...Bufkit profiles suggest mixing will rapidly be on the
increase across the waters early this evening with the frontal
passage. An abrupt wind shift to the northwest will occur and become
aligned through an increasingly deep layer through the night. This
will allow for gale force winds to continue during the overnight
period. Strong cold air advection will add to the wind gust
potential. Light freezing spray will develop with the cold air
advecting over the waters.
A narrow ridge axis will build over the waters Sunday, however the
gradient will still allow for SCA thresholds to be exceeded. By
Sunday night, winds will veer to the southwest as the gradient
increases between a large ridge of high pressure off the Eastern
Seaboard and a frontal system approaching from the northwest.
Long Term...SCA conditions continue into Monday afternoon, at
which both wave heights and winds will begin to slacken. Winds
shift SE Tuesday afternoon, with some Gale conditions possible.
Wave heights also respond increasing 4 to 7 ft through
Wednesday.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...None.
NH...None.
MARINE...Small Craft Advisory until 7 AM EST Sunday for ANZ151-153.
Gale Warning until 7 AM EST Sunday for ANZ150-152-154.
&&
$$
SYNOPSIS...
NEAR TERM...Arnott
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
Area Forecast Discussion
National Weather Service Spokane WA
346 PM PST Sat Feb 19 2022
.SYNOPSIS...
A cooler and showery weather pattern is expected for the remainder
of the weekend into Monday. Moderate to locally heavy snow
accumulations are likely for the Cascade crest and the Idaho
Panhandle mountains. The chance for valley accumulations will
increase Sunday Night into Monday morning as colder air arrives.
Bitter north winds will develop Monday and Monday night bringing
a return of winter temperatures to our region.
&&
.DISCUSSION...
Today through Sunday: A Pacific cold front is sweeping across the
region this afternoon from the northwest. A lack of deep layer
moisture and strong westerly flow has kept the bulk of the
precipitation with the front near the Cascade crest and Idaho
Panhandle. Breezy winds will gradually subside this evening.
Tonight into Sunday temperature lapse rates will increase as a
cold pool at 500mb tracks over the region. This will result in an
unstable atmosphere promoting showery weather. Moist, unstable,
upslope flow into the Cascade crest will really ramp up the snow
showers. This is even more true in the Puget Sound Convergence
Zone with several mesoscale models showing Stevens Pass to be
impacted for at least part of the night beginning this evening.
The National Blend of Models is giving this location 20" of snow
through Sunday afternoon. A Winter Storm Warning remains in place.
With some continued mid level westerly flow models are showing
the greatest focus of showers through Sunday over the Cascades and
Idaho Panhandle. Snow levels will gradually lower to 1500-2500
feet by Sunday afternoon but the bulk of the accumulations should
stay in the mountains. Lookout Pass as well as the Blue Mountains
will likely be impacted by several inches of snow so have issued a
Winter Weather Advisory for these areas. One caveat to the idea
of mainly mountain snow through Sunday is the last couple NAM
model runs which show a band of moderate to heavy showers
developing in a west- east convergence band around Wilbur to
Spokane/Coeur d`Alene Sunday morning which could yield a surprise
band of wet snow accumulations. But with other models weaker or
non existent with idea this solution carries low confidence.
Sunday Night into Monday an arctic front begins to sag south into
the region. Typically arctic fronts from the northeast follow a
slower timing as the Rocky Mountain Divide slows the forward
progress of the front. The 12z ECMWF is one of the slower
solutions and followed this idea, which is close to the timing of
the morning HRRR runs. The arctic air is expected to reach the
North Idaho Panhandle Sunday night, before tracking into the
Spokane area and Upper Columbia Basin Monday morning and then down
into southern WA/Lewiston area by late Monday afternoon. Models
continue to show an unstable atmosphere along and ahead of the
front. Frontal forcing may produce a band of accumulating snow
with the front with the highest threat over the Idaho Panhandle
and eastern third of WA per ensemble data. But can not rule out
some light snow with the front for any given area. Given most
areas will have a threat of light snow have trended up POP`s
towards the SREF. Gusty northeast winds will develop behind the
front with models continuing to show the highest winds through the
Purcell Trench of North Idaho, and across the Upper Columbia
Basin. JW
Monday night through Saturday: The Inland Northwest will be in a
much colder, but drier pattern this period. A broad trough and
north to northeast flow will draw in the drier arctic early this
week. The flow will keep some snow chances going near the Cascades
and Blue Mountain Monday night. The more notable feature will be
the breezy to windy conditions. A tight northeast to southwest
pressure gradient will contribute to this through Tuesday before
slackening Tuesday night onward. Right now winds are forecast to
be in the 15-25 mph range outside of the sheltered mountain
valleys, with gusts of 30 to 40 mph. The forecast highs and lows
from Monday night to Wednesday will be around 20 degrees below
normal, meaning lows in the single digits and lower teens and
highs in the upper teens to 20s. Combined with the aforementioned
winds, we could be looking at some dangerous wind chills Monday
night into Tuesday morning. This includes the north Idaho and
northeast WA valleys, the Spokane/C`dA area, Palouse and the
Upper Columbia Basin, where wind chills of -10 to -20 F may be
seen.
From Wednesday to Saturday the winds slacken and temperatures
slow begin to moderate with the cold trough slowly losing its
influence. It is not until Saturday that highs come closer to
seasonal normals, but not quite make it there. An upper
disturbance passing in the northwest flow will have to be
monitored for possible snow chances around Thursday, but right now
the risk is too low to include in the forecast. A better chance
arrives next Saturday as a system approaches from the west, but
there are still model disagreements on how quick the flow turns
southwest to carry that system inland. /Cote`
&&
.AVIATION...
00Z TAFS: Breezy to locally windy conditions are expected through
early this evening behind a cold front. Showers will develop
through the evening and overnight hours for the ID Panhandle and
eastern third of WA. Given the convective nature and a potential
area of mid level convergence for added lift around Spokane/Coeur
d`Alene there is quite a bit of model differences regarding the
coverage and intensity of the showers. The highest focus per
ensemble data is expected on the Palouse into the LC Valley and ID
Panhandle. Snow levels will be around 2000-3000 feet late tonight
possibly dropping to 1500-2500 feet Sunday AM. JW
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 31 40 24 27 7 21 / 20 40 40 60 0 0
Coeur d`Alene 31 39 23 25 6 19 / 40 60 60 60 0 0
Pullman 33 39 26 31 9 22 / 40 60 50 70 0 0
Lewiston 39 47 31 38 19 28 / 20 60 40 60 10 0
Colville 25 41 26 29 3 22 / 30 30 30 30 10 0
Sandpoint 31 37 20 23 6 18 / 50 50 60 50 0 0
Kellogg 31 36 21 24 3 14 / 80 90 80 60 0 0
Moses Lake 31 47 29 35 13 27 / 0 10 10 30 0 0
Wenatchee 33 46 31 34 13 23 / 10 10 10 40 10 0
Omak 26 44 25 33 11 25 / 0 20 20 20 10 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Winter Weather Advisory from 10 PM this evening to 10 AM PST
Monday for Central Panhandle Mountains.
WA...Winter Storm Warning until 4 PM PST Sunday for Western Chelan
County.
Winter Weather Advisory from 10 PM this evening to 4 AM PST
Monday for Northeast Blue Mountains.
&&
$$
Area Forecast Discussion...RESENT
National Weather Service Pueblo CO
306 PM MST Sat Feb 19 2022
.SHORT TERM...(This evening through Sunday)
Issued at 304 PM MST Sat Feb 19 2022
Key Messages:
1)Warm and quiet the rest of today.
2)Critical Fire Weather conditions possible along southern I-25
tomorrow afternoon.
Currently...
Clear skies and warm temperatures continue across the CWA this
afternoon. A few areas are seeing gusty winds, including some of our
mountain passes and the far southeast plains, with SPD gusting to
around 40 knots. Even so, conditions are still not quite meeting
thresholds for fire weather highlights.
Rest of Today-Tomorrow...
Winds will die off a bit this evening as flow aloft turns more
westerly. Low temperatures tonight will be slightly warmer than last
night, with mid-high 20s over the plains, while the higher terrain
and mountain valleys will still be seeing single digits. Skies are
also expected to remain mostly clear. The warming trend from the
previous several days will continue into Sunday, with high-40s to
low-50s over the valleys, and high-60s to potentially low-70s
possible over the plains, with the warmest temps expected closer to
the KS border. RH will be a bit lower across the area than today,
with values in most areas over the plains dipping below critical
thresholds. When looking at the fire weather concerns for tomorrow,
the limiting factor will be the wind. Most guidance kept sustained
winds near or below 10 knots or so, with a few gusty areas appearing
sporadically throughout the afternoon. However, a few of the models,
including the latest HRRR and the NBM, pick up on some potential gap
flow just east of the mountains over I-25. In accordance with these
possible conditions, have hoisted a Fire Weather Watch over the
southern I-25 corridor. Have left everything north of Pueblo County
out of it for now, as gusty conditions appear spotty and
inconsistent. These potential conditions will persist well into the
afternoon and early evening, after which winds are expected to die
off while RH recovers.
.LONG TERM...(Sunday night through Saturday)
Issued at 304 PM MST Sat Feb 19 2022
Key Messages:
1) Above normal warmth continues on Monday ahead of approaching cold
front.
2) Critical fire weather conditions will be possible across the
southeast plains Monday.
3) A return to winter-like weather early next week, with impactful
mountain snows and much colder weather expected across southern
Colorado.
Will begin to see the next system to impact the region moving into
the western CONUS early Monday, with a digging trough and southward
moving cold air approaching the region. Associated cold front will
be diving south during the day on Monday, though much of the plains
now look to remain in the warmer air longer. Given the strength of
the air mass dropping south during this time, would anticipate the
front to quickly push south. However, it is appearing that some mid
level energy will eject overhead on Monday and help with a
developing low over the eastern plains. This will likely help keep
the front to the north slightly longer, along with supporting a
strengthening wind field. While not quite as warm as Sunday, another
day of above normal warmth is expected over the eastern plains,
along with continued fire weather concerns. It`s now appearing that
falling dew points and RH values and increasing west southwest winds
will support critical fire weather conditions over portions of the
southeast plains Monday afternoon and could see the need for fire
weather headlines with later forecasts.
By late in the day Monday and especially Monday night, upper trough
will continue to shift east and while cold front pushes south across
the plains. This will shift focus towards the expected colder
conditions next week, along with increasing snow chances over much
of southern Colorado. Some potential for some stronger gusts with
the FROPA Monday evening with some guidance hinting at the potential
for these stronger gusts. At this time though, any gusts don`t
appear to be overly strong or widespread. Snow will likely be
ongoing across the Continental Divide Monday night, with some
potential for snow along the Palmer Divide. Additionally, forecast
sounding across the eastern plains do indicate some increasing low
level moisture and low level omega post fropa. With a briefly
lingering warm nose and lacking deep moisture, there would be some
concern for light freezing drizzle over the eastern plains. Low
confidence on this scenario, but will continue to keep a close eye on
it.
While still some uncertainty with the system`s evolution, there are
features that continue to stand out. One is with the rather cold air
mass that is anticipated to settle in, with guidance showing really
cold 700mb temps in place through the middle part of next week. This
will support well below normal temps over the CWA during that time,
and possibly persisting through the end of the work week. Several
nights during this time frame are anticipated to observe low temps
near or below zero over much of southern Colorado. Also during this
time, really low wind chills will be a concern and given how the
system may unfold, it`s possible that some locations may see a
longer period of values well below zero. Still continue to see
signals for impactful snow over the higher terrain, especially
across the southwest mountains, among varying guidance. Southwest
flow really sets up out ahead of this initial main upper trough and
then looks to continue out ahead of another approaching trough.
While this setup will favor higher snow across the southwest
mountains, other locations along the Continental Divide as well as
the eastern mountains look to periodically observe favorable flow
and synoptic support. Confidence with snow across the lower terrain
is low, though still remains a distinct possibility. While
accumulating snow will be possible across the lower terrain next
week, it`s still too early to know exact amounts, impacts, and
location at this time. Will continue to keep a close eye on this
potential though, as some guidance is showing the possibility for
multiple periods of travel impacts over the I-25 corridor and other
main highways.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 304 PM MST Sat Feb 19 2022
VFR conditions are expected at KALS, KCOS, and KPUB over the next 24
hours. South to southwest winds gusting up to 30 knots will be
possible later this afternoon over the far southeast corner of the
state.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
Fire Weather Watch from Sunday morning through Sunday afternoon
for COZ228>230.
&&
$$
SHORT TERM...GARBEROGLIO
LONG TERM...RODRIGUEZ
AVIATION...GARBEROGLIO