Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 02/09/22
Area Forecast Discussion
National Weather Service Buffalo NY
1004 PM EST Tue Feb 8 2022
.SYNOPSIS...
Lake snows east of Lake Ontario will bring a few inches of
accumulation tonight and again late Thursday afternoon into Thursday
night. Otherwise, looking at mainly nuisance rain/snow showers at
times with temperatures generally above normal for the rest of the
work week.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
Sharp mid-upper level trough is crossing region today with H5/H7
temps down to -30c/-16c per RAP analysis. Lake effect snow showers
are expected to continue this evening, mainly east of Lake Ontario
with larger scale forcing from the trough and longer over-water
fetch on westerly flow across Lake Ontario. Inversions rise to 6-
8kft briefly this evening before falling later tonight as warm air
advection quickly develops downstream of next upper trough and sfc
low diving across the northern Plains to Upper Great Lakes. Still a
window of time, through late evening where if flow aligns and
persists long enough several inches of lake effect snow could occur
across northern Oswego county into southern Jefferson county
eastward across the Tug Hill, before backing return flow and warm
air advection spell end to the lake effect. Right now appears
majority of snow will remain east of Oswego and south of Watertown,
but could impact I-81 at times.
Otherwise tonight, expect diminishing snow showers elsewhere with
skies becoming partly cloudy as the trough quickly shifts east.
Temps will fall off this evening western NY to Genesee Valley upper
teens to near 20, before becoming steady or slowly rising late
tonight. Temps east of Lake Ontario will fall to the middle teens by
late tonight.
We`ll flip the pattern tomorrow, at least briefly as strong warm air
advection ramps up in the morning ahead of the Upper Great Lakes
system. Temps will rocket up through the 30s and reach into the
lower to maybe middle 40s by early afternoon before temps fall back
late in the afternoon as leading cold front returns to region from
the west. Mid to high clouds ahead of the system, then thickening
clouds in the afternoon. Weak lift ahead of the front may
result in a few showers, mainly in form of rain, mid to late
afternoon. Then colder air working in late behind the cold
front could lead to rain/snow mix. Light intensity to any precip
through the day. Soundings indicate LLJ that accompanies the
warm front may begin to mix down in the afternoon as cooler air
arrives, leading to southwest winds gusting 20-30 mph near Lake
Erie and over western Niagara Frontier in the afternoon.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/...
A pair shortwaves and fronts will bring progressively colder air
across the region with chances for snow showers through
Thursday...along with some enhanced snow shower activity ENE of the
lakes.
Thursday evening...behind the final front 850 hPa temps drop down to
-10C/-12C over the lakes as the trough moves over and through the
region. This will likely be enough to support...albeit brief...a
period of accumulating lake snows east of Lake Ontario. A 250-260
flow will initially direct lake snows across S. Jefferson and far N.
Oswego County. The availability of the longer fetch of lake Ontario
and any added upstream connections will lend just enough support to
potentially produce several inches (3-5 inches) of snow before lake
snows track to the north and then diminish by Friday morning.
Off Lake Erie...a similar scenario will unfold but be hampered by
the shorter fetch of the lake which will likely limit accumulations.
That said...thinking guidance is a bit underdone due to ice coverage
represented in the modeling. Have bump up snowfall accumulations
across S. Erie and a small portion of Chautauqua County to reflect
this issue. Even so...it appears we are only looking at a few inches
(1-3 inches). Winds gradually back to the SW then S as we progress
through the night. When this occurs...lake snows will push north and
then quickly weaken as a mid-level warm front pushes into and
through the area.
Friday...any remaining lake snows will end early in the morning as
warm air advection processes take over. This will leave the area
precipitation free ahead for much of the day ahead of the next
clipper and cold front. High temps climbing to near 40F.
Friday night...clipper and its cold front approach the region with
increasing chances for snow showers overnight.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
Arctic cold front plows across western and northcentral NY Saturday
morning. A mix of rain and snow showers with the front initially
will quickly transition to all snow from northwest to southeast by
early afternoon, then taper off to scattered snow showers behind the
boundary during the second half of the day. The other signature of
this boundary will be the much colder air that filters in across the
area in the wake of the front for the second half of Saturday right
through the first part of the new work week, with at least the
chances for some limited lake effect snow downwind of the Lakes
Saturday night and Sunday.
Next upper level trough and associated moisture starved cold front
will bring a reinforcing shot of cold air and possibly some
scattered snow showers as it crosses the area Sunday night. Next
weak clipper type system moves through the area to start the new
work week with some light snow showers possible Monday and Monday
night, before high pressure builds in Tuesday with increasingly
drier weather expected.
Otherwise, highest temperatures during this entire period will be at
the start Saturday morning. Temps then fall through the day
Saturday, with readings taking a dive back to well below average
right through the end of the period.
&&
.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
Snow showers will remain confined to areas east of Lake Ontario
overnight. A brief heavier snow shower could drop vsby to MVFR
at KART between 04z and 08z.
Otherwise VFR conditions overnight.
Outlook...
Wednesday...Mainly VFR.
Thursday...MVFR to VFR. Chance of snow showers.
Friday through Sunday...MVFR. Chance of snow showers.
&&
.MARINE...
Winds will lower during the overnight into Wednesday as high
pressure moving off to the east backs winds southerly.
A warm front will cross the lake later Wednesday, shifting flow to
the southwest. Low pressure over the northern Great Lakes will
slowly move east and the enhanced pressure gradient will bring a
period of small craft headlines by Thursday.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...None.
MARINE...None.
&&
$$
SYNOPSIS...JLA/TMA
NEAR TERM...JLA/TMA
SHORT TERM...AR
LONG TERM...JM
AVIATION...JLA/SW/TMA
MARINE...TMA
AREA FORECAST DISCUSSION
National Weather Service Wilmington OH
936 PM EST Tue Feb 8 2022
.SYNOPSIS...
High pressure begins to shift eastward but keeps conditions dry
through Wednesday night. Several waves of upper level energy
will keep clouds and chances for precipitation in the forecast
the next several days. A stronger system moves in late on Friday
and pushes out on Saturday, setting up the Ohio Valley for a
cool and mostly dry weekend.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
There is a pretty wide variation in temperatures across the
region this evening, with mid 20s in the cool spots in central
Ohio (25 at VTA) and much warmer conditions in northern Kentucky
(42 at KY Mesonet HHTS). With SSW flow expected to increase over
the next couple hours, would expect little (if any) further
drops in temperatures tonight, with some gradual rises expected
after 06Z. With no model really picking up the current gradient
all that well, the hourly temperature traces were difficult to
project precisely for the next 4-8 hours, but in general min
temps should be close to the current values being observed as of
9PM.
Based on 00Z model data, there remains some subtle evidence of
a weak front aloft (850mb/700mb) just ahead of the mid-level
trough axis, roughly coincident with where the HRRR is
suggesting a narrow band of light rain/snow may develop tomorrow
morning. Will keep the low-end PoPs for this feature, though
would expect most places will be unlikely to receive anything
measurable.
Previous discussion >
A broad region of high pressure remains stretched across the
Ohio Valley down through the lower Appalachians and into the
Gulf. This high pressure system gradually shifts eastward
throughout the day. Return flow on the back side of the high
will begin to advect warmer air in from the Gulf. Even though
skies do become mostly clear overnight, sustained southerly
winds of 5-10 mph should help moderate temperatures and keep
lows to near or just below freezing across our CWA. During this
period, influence of the high pressure will keep conditions dry.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
An H5 trough and its associated PVA traverses the ILN fa
Wednesday morning, which could offer some isolated to scattered
pcpn as a rain-snow mix during the morning. Several hi-res
models do show this potential weak line of pcpn traversing our
CWA in the morning, so decided to include slight chance to low
end chance for PoPs during this timeframe.
The afternoon should offer a relatively dry period for our
counties before the primary cold front moves in later during the
evening. Skies will generally remain mostly cloudy to overcast
throughout the day with the low levels continuing to saturate.
Majority of our counties south of I-70 should observe highs
above 40, with counties near/south of the OH River potentially
observing temperatures near 50 with the enhanced WAA during the
day.
By the evening, a surface cold front will begin to move in from
the west, increasing chances for pcpn. While majority of models
(as well as the HREF) do show a good signal for pcpn, the
overall QPF remains very light, so PoPs generally remain in the
chance category for now due to lower coverage. Light snow
accumulations will be possible in our northern counties along
and N of I-70, but snow accumulation should be pretty limited.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
Positively-tilted mid-level trough will pass across the area at the
beginning the period which, combined with low level cold air
advection, will keep a good amount of cloud cover over the region
until late in the day. Surface high pressure will quickly move east
Thursday evening with a fairly strong pressure gradient developing
ahead of the next approaching system. So expect temperatures to drop
quickly during the evening but then steady out and even start to
rise before daybreak Friday.
Strong mid-level short wave will pass across the Great Lakes on
Friday into Friday night. This will push a cold front across the
area. Precipitation will occur with this system, mainly as rain. But
if precipitation starts early enough on Friday or lingers late
enough into Friday night, there could be some snow. There is also
some potential for light precipitation to persist into Saturday
morning. There will be a large temperature gradient across the
forecast area on Friday with highs ranging from the lower 40s in the
north to the mid 50s in the south. After the front moves through,
there will be a return to below normal temperatures area wide.
Long wave trough will remain across eastern North America into early
next week. A stronger impulse will drop into this trough on Monday,
but with some uncertainty with moisture availability, kept PoPs low.
Once this system moves through, ridging will ensue with the
beginning of some moderation in temperatures.
&&
.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
VFR conditions are expected through most of the TAF period. LLWS
will be likely to occur overnight, along with surface winds out
of the south / south-southwest to around 10-12 knots. This will
persist through early Wednesday morning.
There may be some brief showers (perhaps a very light rain/snow
mix) moving through some of the airports in the 13Z-16Z time
period, but no significant impacts are expected. Some
precipitation chances may also occur very late in the TAF
period, but chances are too low to include in any of the TAFs
except KDAY as of now.
OUTLOOK...MVFR ceilings are possible at times through Thursday,
and MVFR ceilings are possible again on Saturday.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...None.
KY...None.
IN...None.
&&
$$
SYNOPSIS...Clark
NEAR TERM...Clark/Hatzos
SHORT TERM...Clark
LONG TERM...
AVIATION...Hatzos
Area Forecast Discussion
National Weather Service Lincoln IL
848 PM CST Tue Feb 8 2022
.SYNOPSIS...
Issued at 239 PM CST Tue Feb 8 2022
Temperatures are expected to warm into the upper 30s to lower 40s
Wednesday which will continue to slowly eat away at the deep snow
pack across much of central Illinois. A few widely scattered
showers are possible Wednesday afternoon and evening, but most of
the day will remain dry. The next chance for more widespread rain
and snow arrives Thursday night and continues into Friday.
&&
.UPDATE...
Issued at 848 PM CST Tue Feb 8 2022
A weak cold front is moving into the Illinois River Valley this
evening, and will reach Indiana by sunrise. The front will produce
a shift to westerly winds and be associated with mid-level cloud
cover, but will have a fairly subtle cooling behind it, and very
little chance of precipitation. A couple high-res models depict a
weak precipitation band as it enters Indiana, so will leave a
chance of flurries in forecast from I-57 eastward after midnight.
Otherwise, lows look to be upper 20s most areas, upper 30s south
of I-72. Afternoon forecast package needs no significant updates.
&&
.SHORT TERM...(This evening through Wednesday)
ISSUED AT 239 PM CST Tue Feb 8 2022
Through Wednesday, an upper trough will slowly shift east across
the Great Lakes while, at the surface, low pressure currently
centered over Manitoba will shift to eastern Ontario/James Bay. A
weak trailing front will pass across central Illinois tonight
followed by another cold front Wednesday afternoon. Do not
anticipate any significant weather from tonight`s front other than
a modest wind shift to westerly and increasing mid and high
clouds. Couldn`t completely rule out some isolated
sprinkles/flurries, but most of central Illinois will remain dry
overnight. Winds will back to the southwest again Wednesday
morning ahead of the next front which will contribute to another
mild day considering the deep snow pack still in place across the
area. With this second wave, expect steepening low and mid level
lapse rates with the top of mixed layer positioned within the snow
growth zone. This could allow for isolated to widely scattered
showers to develop during the late afternoon and evening as an H5
vort max pivots across portions of central and northern Illinois.
While global guidance generally favors the northern half of the
state for any precip, the RAP and HRRR indicate the potential for
showers across the entire CWA so have added slight chance PoPs to
account for this possibility. Boundary layer temperatures are warm
enough to support a mix of rain and snow Wednesday afternoon and
evening, though dynamic cooling from any heavier showers should
support a transition over to snow. If any snow showers develop, a
quick dusting is possible, but overall coverage is expected to
remain low to mitigate the threat of widespread impacts.
.LONG TERM...(Wednesday night through Tuesday)
ISSUED AT 239 PM CST Tue Feb 8 2022
Northwest flow aloft will be the general rule Thursday through at
least the weekend with a number of shortwave digging across
portions of the Great Lakes and Midwest. Temperatures return to
below normal Thursday as H85 thermal trough is centered over the
Midwest. A strong wave is progged to dig across the Canadian
Prairies into the northern Great Plains Thursday into Friday. In
response, shortwave ridging and mid level warm air advection will
overspread portions of the Midwest in advance of this trough which
will help push temperatures back into the 40s at least briefly on
Friday followed by the next chance for precip starting Thursday
night. Precip may begin as snow before changing over to rain as
the column warms. A strong cold front will push across central
Illinois later Friday with precip chances diminishing in its wake.
Over the weekend, a strong 1040mb high will spread southeast from
the northern Great Plains and Upper Midwest. The ridge axis will
move across Central Illinois Sunday morning bringing back the next
chance for single digits temps to the area. A reinforcing cold front
will move across the region Sunday night prolonging the cold temps
into Monday of next week.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 542 PM CST Tue Feb 8 2022
VFR conditions expected through tonight as a cold front brings
additional mid and high level cloud cover. An upper level
disturbance arriving Wednesday afternoon will bring more moisture
and cloud cover, with central IL having predominantly MVFR cigs or
lower VFR and possibly a few showers. Winds S 09-13 kts this
evening, shifting to W and gusty after the cold front moves trough
around 03Z-06Z. W winds continuing through the forecast period,
and remaining 08-12 kts with higher gusts.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...37
SYNOPSIS...Deubelbeiss
SHORT TERM...Deubelbeiss
LONG TERM...Deubelbeiss
AVIATION...37
Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
642 PM CST Tue Feb 8 2022
.SHORT TERM... (Through Late Wednesday Night)
Issued at 217 PM CST Tue Feb 8 2022
An upper-level shortwave trough traversing the Midwest will force a
cold front southeastward through the CWA this evening. Given that
low and mid levels will be quite dry (PW <0.5") and ascent is not
anticipated to be vigorous, passage of this front will devoid of
precip and only mark the onset of weak CAA as low-level flow veers
to the west-northwest in its wake.
Another upper-level shortwave trough will arrive in Wednesday
with another cold front pressing southeastward through the region.
The combination of cyclonic flow through a deep vertical layer,
steepening low-level lapse rates (from CAA maximized around 700
hPa), and marginal low-level moisture could also be sufficient to
yield isolated rain showers across east- central and south-central
IL with weak low-level convergence along the cold front during
the late afternoon/evening. The 18z HRRR is the most aggressive
with this scenario, even generating 100 to 200 J/kg of MUCAPE, but
its solution is likely contaminated by erroneously high surface
dewpoints. A few snow flakes could mix with the rain as the
boundary layer cools during the evening. Behind the first front,
temps at 850-hPa will cool 7 to 10 C between today and Wednesday,
but with surface winds and low-level flow predominantly westerly
ahead of the second cold front high temps will again be above
average and only up to 10 F cooler (in the low-40s to mid-50s F).
Reinforcement of CAA will occur again behind this second front.
Pfahler
.LONG TERM... (Thursday through Next Tuesday)
Issued at 217 PM CST Tue Feb 8 2022
Prevailing weak CAA will continue into Thursday with high temps
approximately average for early/mid-February. At upper levels, time-
mean northwesterly, broadly cyclonic flow will remain established
over the Midwest through the remainder of the week and into early
next week. This flow will be navigated by a continued parade of
upper-level shortwave troughs, partially consisting of a weak
shortwave trough early Thursday and a sharper, more robust shortwave
trough propagating across the region late Thursday night/Friday.
This second shortwave trough will send a stronger cold front through
the CWA, relative to its predecessors. There should be greater
moisture, although still somewhat limited, available to interact
with more vigorous ascent stemming from pre-frontal WAA and low-
level convergence along the front. Therefore, light precip will be
possible ahead and along the cold front late Thursday night into
Friday. Some wintry precip cannot be ruled out briefly initially
Thursday night, but strong WAA should quickly raise temps above
freezing, favoring rain thereafter. Friday could be another warm day
across the CWA with strong low-level southwesterly flow, deeper
mixing near the front, and a majority of the snowpack likely eroded
by that point from previous days of melting. The exact magnitude
of warmth will hinge upon the timing of frontal passage with later
a later passage favoring warmer temps than currently forecast.
Behind the cold front, CAA will facilitate the arrival of a much
colder airmass Friday night with 850-hPa temps falling to around -15
to -18 C (-1 std dev below average). This airmass will promote below
average temps through Saturday. However, yet another upper-level
shortwave trough will traverse the Midwest around Sunday, providing
a brief moderation and then cooling of temps into Monday. Global
model guidance are indicating that a large-scale upper-level flow
pattern change will take place across the CONUS shortly following
this shortwave trough`s departure, breaking the northwesterly flow
regime.
Pfahler
&&
.AVIATION... (For the 00z TAFs through 00z Wednesday Evening)
Issued at 639 PM CST Tue Feb 8 2022
VFR flight conditions are expected to prevail through Wednesday.
A weak cold front will move through the region on Wednesday. Some
lower VFR clouds between 4000-8000 feet will likely accompany the
front, and there may be a few sprinkles along and east of the
Mississippi River, but no major impacts are expected other than a
wind shift to the west-northwest.
Carney
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...None.
IL...None.
&&
$$
WFO LSX
Area Forecast Discussion
National Weather Service Paducah KY
Issued by National Weather Service Springfield MO
521 PM CST Tue Feb 8 2022
.SHORT TERM...(Tonight through Thursday)
Issued at 233 PM CST Tue Feb 8 2022
A mild day is occurring across the quad state region this
afternoon as temperatures have warmed into the upper 40s to mid
50s thanks to southwesterly winds and sunny skies.
Some cloud cover moves into the area overnight into tomorrow as a cold
front passes west to east across the region on Wednesday
afternoon into evening. Due to the later passage of the front,
high temperatures on Wednesday will again be mild and very similar
to today. Weather should generally remain dry given a relative
lack of moisture with the frontal passage, but the RAP and HRRR
short term models do suggest some low-end isolated shower chances
across southern Illinois and Indiana. Have included slight chance
PoPs Wednesday evening to account for this.
Dry conditions and slightly cooler temperatures in the 40s to low
50s (coldest over the northern CWA) are in store for Thursday
under mostly clear skies a weak surface high pressure moves over
the quad state region.
.LONG TERM...(Friday through Tuesday)
Issued at 233 PM CST Tue Feb 8 2022
Overview:
Overall, this portion of the forecast looks predominately dry,
though some low end precipitation chances will be possible again
on Friday and Saturday despite some model variance.
The upper-level pattern late this week into early next week will
be mainly defined by west to northwesterly flow across the region
given am upper-level ridge over the eastern Pacific and western
CONUS and a general troughing pattern over the eastern half of the
CONUS.
Friday-Tuesday:
Inside this northwesterly upper-level pattern, a couple shortwave
trough/surface cold front pairs are expected across the region:
the first on Friday evening into Saturday and another on Sunday
night into Monday. The overall moisture return with these systems
are lacking, but the GEFS does show a weak remnant of Pacific
moisture present with the Friday-Saturday system. This could be
just enough moisture to produce some light, measurable
precipitation for the area, but chances are low at the moment. If
we do see precipitation with the Friday-Saturday system, it looks
to be mainly in the form of rain, but could briefly mix with snow
if any precipitation falls Friday night. The Sunday night clipper
system looks to be even more moisture starved, so this is
currently reflected in a dry forecast for Sunday night-Monday.
A colder airmass moves in behind the late Friday cold front,
dropping high temperatures back into the 30s for Saturday and
Sunday.
Model consensus is in fairly good agreement on a shortwave ridge
moving over the central CONUS early next week, which should lead
to temperatures gradually warming back to near 50 degrees by
Tuesday with the early portion of the week remaining dry.
Mid-late next week:
Larger upper-level troughing digs through the Rockies into the
central CONUS, with an associated surface low developing with it.
Ensemble guidance hints at a better fetch of western Gulf moisture
being brought northward with this system, with a potentially
wetter pattern in store for this timeframe further backed by a wet
signal in the CIPS extended analog guidance.
&&
.AVIATION...
Issued at 514 PM CST Tue Feb 8 2022
Initially clear skies will continue into tonight before some mid
level cloud cover slides over the region. Despite clouds moving
over the area, VFR flight conditions will prevail.
In advance of an approaching dry cold front, low level winds shear
will impact the areas TAF sites into the early morning before
diminishing early in the morning.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...None.
MO...None.
IN...None.
KY...None.
&&
$$
SHORT TERM...WFO SGF
LONG TERM...WFO SGF
AVIATION...WFO SGF
Area Forecast Discussion
National Weather Service Pendleton OR
756 PM PST Tue Feb 8 2022
.UPDATE...A few light showers developed across the Lower Columbia
Basin and the northern Blue Mountains this evening but trace
amounts were observed. Any shortwave on satellite is not
discernible but WSR-88D did show returns around 20-40dBZ. The
shortwave also caused winds to increase to around 15-20 mph in
the Kittitas Valley and the eastern Columbia River Gorge where a
cross-Cascade gradient is present, albeit weak. The HRRR did a
great job initially with the composite reflectivity, as it showed
the showers dissipating at this time. The precipitation has
encountered subsidence with the stable high pressure and has
mostly ended. Forecast was updated to add sprinkles earlier this
evening in the Columbia Basin and Blue Mtn Foothills as well as
bump up winds slightly in the Eastern Gorge and Kittitas Valley.
Wister/85
&&
.PREV DISCUSSION... /issued 217 PM PST Tue Feb 8 2022/
SHORT TERM...Today through Thursday...An upper-level ridge is
currently parked off the coast of the Pacific Northwest and is
expected to persist through the period. As far as sensible weather,
a weak shortwave combined with some modest Pacific moisture wrapping
around the top of the ridge will lead to a slight chance of light
rain and light high-elevation snow for the Washington Cascades,
northern Blue Mountains, and Wallowas/adjacent high terrain in
Wallowa County tonight through Wednesday morning. This increased
moisture and perhaps a bit more cloud cover may also serve to
moderate tonight and Thursday morning`s lows compared to what was
observed this morning. Additionally, periodic breezy conditions
through the Kittitas Valley and adjacent high terrain may occur
through Thursday afternoon.
Perhaps the most notable point of discussion is afternoon high
temperatures each day. Highs will range from the low 50s to low 60s
this afternoon for much of the forecast area, though some higher
valleys in northeast Oregon have yet to mix out and are stuck in the
20s and 30s. 850 mb temperatures are forecast to rise through the
period, so expecting afternoon highs of mid 60s to 70 possible
Thursday across central Oregon. More uncertainty exists for the
Foothills of the Blue Mountains, the Columbia Basin, and the
aforementioned high valleys due to the potential for strong
subsidence inversions to set up. Should the inversions lead to the
development of stratus decks, fog, or just fail to fully mix out for
the aforementioned areas, afternoon highs could be significantly
cooler than forecast. The NAM is currently advertising this
situation for the Washington side of the Columbia Basin and adjacent
valleys Wednesday and Thursday, though other guidance is not as
aggressive with the stratus and thus have warmer afternoon highs.
Have opted to keep afternoon highs a few degrees warmer, nudged
towards the 50th percentile for the NBM as this is generally a
few degrees warmer than the deterministic NBM. Plunkett/86
LONG TERM...Friday through Tuesday...A ridge of high pressure
centered along the coast will move inland late Friday and Saturday
continuing the warm and dry trend into the weekend. The ridge will
then flatten on Sunday as an approaching upper level trough
approaches from the Gulf of Alaska. This trough will push a cold
front through the region late Sunday night and Monday followed by
the trough passage Monday night and Tuesday. The front push a band
of precipitation across the forecast area on Monday mainly impacting
the Cascades and eastern mountains with some rain changing to snow
as snow levels lower. Behind the front there will be increasing
westerly winds which will linger into Tuesday. Precipitation will
also taper off to showers over the mountains on Tuesday.
AVIATION...00Z TAFS...Mid and high level clouds coming over the
ridge will provide BKN-OVC AOA 10-15K through the period with some
FEW-SCT 070-12K. This will allow VFR conditions to prevail. Winds
will generally remain less than 10 kts.
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 36 56 35 60 / 10 0 0 0
ALW 39 57 37 60 / 10 0 0 0
PSC 35 52 34 52 / 10 0 0 0
YKM 31 53 29 54 / 0 0 0 0
HRI 37 53 35 57 / 10 0 0 0
ELN 34 47 32 49 / 0 0 0 0
RDM 33 62 33 68 / 0 0 0 0
LGD 32 47 32 51 / 0 0 0 0
GCD 33 52 32 59 / 0 0 0 0
DLS 42 58 40 61 / 0 0 0 0
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...None.
WA...None.
&&
$$
UPDATE...85
SHORT TERM...86
LONG TERM....91
AVIATION...91