Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 01/23/22
Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
902 PM EST Sat Jan 22 2022
.UPDATE...
Sufficient magnitude to low level drying in the wake of the first in
a trio of clipper systems will effectively offer a window of benign
conditions as support wanes for snow shower production overnight.
Forecast through 09z will continue to call for the occasional flurry,
but rapid loss of even a stratocu field off lake Michigan indicative
of the increasingly unfavorable enviroment for greater downstream
moisture flux.
Attention Sunday morning tied to the next clipper on pace to pivot
across the Ohio valley. Meaningful large scale ascent marking the
inbound height falls still expected to sweep across southeast
Michigan 09z-15z. Given the synoptic improvement in moisture
quality, this should prove sufficient for a widespread, light
accumulating snowfall for areas mainly south of the I-69 corridor. A
more localized axis of deeper ascent appears to manifest within the
I-94 corridor and Ohio border region, as a noted uptick in mid level
deformation engages a southward advancing frontal boundary. Some
iterations of the HRRR and RAP offer an elevated response within
this corridor, suggesting there remains some forecast sensitivity to
the possibility of a smaller scale, moderately intense fgen band. A
general 1 to 2 inch accumulation remains highlighted within this
corridor, highest amounts toward the Ohio state line. Elsewhere,
accums below an inch on target.
&&
.PREV DISCUSSION...
Issued at 632 PM EST Sat Jan 22 2022
AVIATION...
Lingering window through roughly 02z for light lake effect snow
showers to transit the southeast Michigan airspace. Intervals of
MVFR conditions will exist during this time. Upstream trends lend
confidence in some improvement in cloud bases toward prevailing
lower VFR for a period overnight /03z-09z/, with a slightly drier
low level environment also supporting a decrease snow shower/flurry
coverage. A modestly gusty west-southwest wind this evening,
gradually veering with time from PTK northward overnight as a weak
boundary eases across the area. Moisture increases during the mid-
late morning hours north of a low pressure system tracking through
the Ohio valley. This will result in a period of widespread, light
accumulating snow in IFR conditions across the Detroit/PTK airspace.
This moisture glances across FNT/MBS, affording a shorter window of
light snow in MVFR conditions. Improving conditions from north to
south by early afternoon under drier northerly flow. This will ease
ceiling heights back into lower VFR, with a general reduction in
overall coverage of stratus more likely toward evening.
For DTW...Very light snow showers or flurries will persist this
evening /through 02z/, before a brief window of dry conditions
emerge overnight. Upstream trends suggest activity will remain
limited in intensity. A light accumulating snowfall arrives for the
mid-late morning period Sunday /09z-15z/. Potential for accumulation
of around an inch during this time.
DTW THRESHOLD PROBABILITIES...
* High in ceilings aob 5000 feet through Monday morning. Medium
Monday afternoon.
* High for precipitation falling as all snow through the TAF period.
PREV DISCUSSION...
Issued at 401 PM EST Sat Jan 22 2022
DISCUSSION...
Reflectivity data from 1830-2030Z depicts more transient coverage of
lake-supported snow with diminishing rates (sans Tri-Cities). These
lingering snow showers will persist into the late evening hours as
the trailing edge of the PV anomaly lifts northeast and the corridor
of lower isentropic lift is shunted into southern Ontario. Sub-H7
winds then veer WNW stripping away some moisture from the residual
stratus layer before midnight solidifying a brief break in precip.
Given persistent mixing potential tapping into +35 knot 900 mb
winds, also nudged gusts up to 25 knots through 00Z this evening.
Dry mid levels will be shortlived as a second embedded shortwave
trough noses in late tonight, reintroducing middle troposphere
moisture advection. Marked ThetaE convergence after 06Z
reinvigorates the west to east expansion of the mid-cloud layer.
This provides some insulating potential for the southern half of the
forecast area where temperatures should settle in the upper teens to
low 20s. Meanwhile, H8 temps nearing -20C spill south across the Tri-
Cities/Thumb, and coupled with a longer window of partial clearing,
overnight lows approach single digit readings north of I-69 by
daybreak.
The embedded inbound progressive shortwave and associated surface
low will focus further south than today`s disturbance resulting in
minor accumulations along and south of the I-96 corridor where the
baroclinic zone is sharpest. Model trends suggest a Sunday morning
timeframe for the bulk of snowfall, although more limited in spatial
extent. Got more aggressive with PoPs and accumulations for the
southern four counties with between 0.5-1.0 inches by midday
(isolated 1.5 inches). Just a dusting to a coating north of I-69 of
dry snow where FGEN contribution is absent.
After a two week lull in +1 inch snow events (nearly three weeks for
DTW), a system with appreciable snowfall is set to arrive Monday
morning. Low amplitude troughing within the polar jet will support a
sharpening and strengthening jet streak with the core brushing the
MI/OH state-line. Supporting top-down moisture surge complimented by
strong ThetaE advection within the H8-H7 layer ramps up after 06Z
Monday, although the highest specific humidity air holds further
south. Forecast soundings remain cold, so no question that p-type
will continue as snow throughout the event. Currently looking at
SLRs near 15:1, but if the 5-10 kft layer comes in a bit colder, the
depth of the DGZ would expand substantially, increasing the
potential for higher mean SLR and increased snowfall.
18Z model suite has fallen into better agreement regarding the peak
of the event which now appears centered around the evening commute
with snowfall rates near a half inch per hour. The most likely
outcome for snow totals still holds in the 2-4 inch range by Tuesday
morning. Locally higher amounts near 5 inches cannot be ruled out,
especially south of I-94. Will hold off on a Winter Weather Advisory
at this time given the onset is still some 40 hours away and the
duration for the forecast event totals is marginal, particularly for
areas along and north of I-69.
Colder and drier conditions expected for the mid-week timeframe in
the wake of Monday`s system. Surface high pressure from the northern
Plains builds southeast to 1037 mb over eastern Iowa by Wednesday.
There are some hints of isentropic ascent within a canopy of low
stratus supported by anticyclonic advection of lake moisture as the
thermal trough makes its coldest approach. QPF would be low and
coverage isolated-scattered, but far enough out that kept NBM PoPs
at this time. Highs will be stuck in the teens Tuesday and Wednesday
with the cold Canadian airmass, but aforementioned clouds should
prevent a collapse in overnight lows. GFS/ECMWF are out of phase
Wednesday night, onward, but perturbed height field will provide
additional opportunities for precip into the end of the week with a
recovery in thermal profiles by Thursday.
MARINE...
Southwest winds will be on the decrease into this evening cold front
passes over the central Great Lakes late this afternoon and evening.
The Gale Warning was allowed to expire, but there remains a chance
that an occasional gust to gales may occur through this evening.
Post frontal winds will shift to the west with gusts remaining above
20 knots through most of tonight across Lake Huron. A weak high
pressure moving across southern Ontario will shift winds more
northwesterly for Sunday morning with winds at this point 20 knots
or below. The next inbound low pressure system will quickly shift
winds back to the west Sunday evening and eventually towards the
southwest for Monday. Winds will become elevated again late Monday
into Tuesday morning as northwesterly winds bring a reinforcing shot
of arctic air pushes into the region. Forecasts gusts from the
northwest are to around 25 knots. Arctic high pressure will bring
lighter winds Tuesday afternoon into Wednesday.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
Lake Huron...NONE.
Lake St Clair...NONE.
Michigan waters of Lake Erie...NONE.
&&
$$
UPDATE.......MR
AVIATION.....MR
DISCUSSION...KK
MARINE.......AA
You can obtain your latest National Weather Service forecasts online
at www.weather.gov/detroit.
Area Forecast Discussion
National Weather Service Quad Cities IA IL
848 PM CST Sat Jan 22 2022
.UPDATE...
Issued at 843 PM CST Sat Jan 22 2022
Radar suggests an uptick in snow intensity west and north of the
area. This looks to be tied to the largscale ascent moving into
the area. RAP omega in the DGZ suggests that we may see less of a
sharp gradient on the southern end of this system. The HRRR still
thinks its going to be much further north, however the more
convective like returns on the back end of the system suggests
that current forecast is on track, if not a little more snow on
the southern end. Generally the 1-3 looks good across the southern
part of the advisory. We will need to watch what happens as the
rain on the backend transitions into cooler air. Potential exists
for increasing the totals on the southern end of the adv.
Regardless, little changes to overall messaging and impacts
associated with this clipper, just fine tuning of amounts.
&&
.SYNOPSIS...
Issued at 124 PM CST Sat Jan 22 2022
At 200 PM, a shortwave/Alberta Clipper was evident on water vapor
imagery over southeastern South Dakota with clouds spreading into
north central Iowa. A weak frontal boundary was sliding across
eastern Iowa into northwest Illinois. Temperatures ranged from
the upper teens to lower 30s across the area. Cedar Rapids was the
cool spot at 17 degrees while keokuk was the warm spot at 34
degrees. There were gusty westerly winds across the area with
speeds of 10 to 20 knots.
&&
.SHORT TERM...(This Evening through Sunday)
ISSUED AT 124 PM CST Sat Jan 22 2022
Key Messages:
1. There are no adjustments to the Winter Weather Advisory for
tonight.
2. The area of accumulating snowfall has shifted northward
slightly with this issuance. 3 to 5 inches of snow is possible
north and east of a Manchester Iowa to Sterling Illinois line with
1 to 3 inches possible across the remainder of the advisory. There
is going to be a sharp cutoff in accumulating snow south of the
advisory area.
3. Patchy drifting snow is possible overnight with winds of 10 to
20 knots especially in open areas.
Models continua to trend more northerly with this wave and faster
with the bulk of the snow falling between 00 to 12 UTC Sunday. The
main forecast concerns were snowfall amounts.
Models are in very good agreement on the overall forecast over the
next 24 hours. The track of the Alberta Clipper tonight has
trended northward by a few miles. This currently brings the
surface low from Sioux Falls late this afternoon to the Quad
Cities at 06 UTC to central Illinois by 12 UTC Sunday. A band of
FGEN forcing will overspread northern Iowa into southern Wisconsin
this evening and overnight focusing the best lifting and moisture
along the Highway 20 corridor. Soundings will slowly saturate
after 00 UTC as moisture spreads into the area ahead of the wave
with precipitation beginning after between 00 to 03 UTC northwest
of a Cedar Rapids to Dubuque line then spreading southward through
06 UTC.
Model soundings show good saturation through the dendritic growth
zone as the wave moves across the area. Models hold temperatures
in the teens through the event resulting in a snow to liquid
ration of roughly 15 or 20 to 1 with the highest SLRs east of a
Manchester to Sterling line. This results in a 3 to 5 inches of
snow across this area along with 1 to 3 inches possible east of a
Cedar Rapids to the Quad Cities to Princeton Illinois line with a
quick drop off in snow totals south and west of this line.
Additionally, expect winds of 10 to 20 knots between 12 to 18 UTC
Sunday that may result in some drifting of snow through the
morning north of Interstate 80.
The low temperatures for Sunday morning will occurring in the 7
t0 9 AM range as temperatues quickly drop as the clipper exits to
the east and strong cold advection spreads across the area. High
pressure will quickly build into the area for the day on Sunday
allowing clouds to quickly clear with sunshine expected across the
area through the afternoon. High temperatures on Sunday will
range from the lower teens along the Highway 20 corridor to the
lower 20s south of a Fairfield to Galesburg line.
.LONG TERM...(Sunday Night through Saturday)
ISSUED AT 124 PM CST Sat Jan 22 2022
Key messages:
1. Clipper system to bring another chance of light snow Sunday
night/Monday mainly across northeast IA through northern IL. Snow
amounts between a dusting and 2 inches is forecast.
2. Dry conditions and below normal temperatures are expected for
much of the work week, with wind chills approaching advisory levels
(below -20 degrees) Tuesday night and Wednesday night.
Sunday night-Monday...the last in a line of clippers will track
through the CWA bringing another chance of light snow. Most of the
12z model runs and their ensemble members keep the best lift/forcing
and higher snow chances across northeast IA into northern IL. With
that being said, there has been a slight increase in QPF with this
system and now has 0.05-0.20" forecast through Monday 18z. The
higher QPF amounts are now seen across northern IL in Jo Daviess,
Stephenson, and Carroll counties and points east, which will be
closer to the low pressure track. Can`t rule out some light snow
along the cold front across our far southern areas as the 12z NAM
suggests and after coordination with neighbors, have added
slight/chance PoPs for this possibility. Snowfall amounts between 1-
2 inches is possible along and north of a line from Independence IA,
to Clinton, to Princeton IL. Snow totals from a dusting up to an
inch will be possible south of that line. This new snow should fall
prior to the morning commute on Monday for all areas except
northwest IL, where the greatest impacts of snow covered roads and
sidewalks are expected. Snow will end by late morning in all areas.
Breezy northwest winds are forecast Monday afternoon and may keep
temperatures from rising too much throughout the day. Highs should
occur in the morning or early afternoon with readings in the
mid/upper 30s south of I-80, to the upper 20s/low 30s north.
Monday night-Wednesday...large 1037mb surface high will build into
the Midwest bringing dry conditions and below normal temperatures.
850mb temps will drop into the -15 to -17C range keeping highs in
the single digits over fresh snow cover and the lower teens
elsewhere. The coldest night will be Tuesday night, with the
surface high overhead. Lowered min temps some Tuesday night from
the NBM as temperatures will quickly drop into the single digits
and teens below zero by Wednesday morning. These readings will not
be too far off from record lows for CID/DBQ. Even with a light
wind Monday night and Tuesday nights, wind chills will drop into
the -10 to -30 degree range and wind chill headlines will likely
be needed.
Wednesday night-Saturday...return flow develops Wednesday night
ahead of another cold front to move through Thursday. Moisture along
the front will be quite limited and just an increase in clouds is
expected at this time. The rest of the period will bring near to
slightly above normal temperatures and dry conditions with northwest
flow aloft.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday Evening)
ISSUED AT 608 PM CST Sat Jan 22 2022
VFR conditions will come to an end as snow and lower clouds move
into the area in the next few hours. DBQ has the potential for
LIFR vsbys as potentially heavy snow moves in. Winds could be
gusty after the snow and may lead to some blsn. Otherwise, expect
improvement to VFR later in the period.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...Winter Weather Advisory until 6 AM CST Sunday for Cedar-Clinton-
Dubuque-Jackson-Jones-Scott.
Winter Weather Advisory until 4 AM CST Sunday for Benton-
Buchanan-Delaware-Linn.
IL...Winter Weather Advisory until 6 AM CST Sunday for Bureau-Carroll-
Henry IL-Jo Daviess-Putnam-Rock Island-Stephenson-Whiteside.
MO...NONE.
&&
$$
UPDATE...Gibbs
SYNOPSIS...Cousins
SHORT TERM...Cousins
LONG TERM...Gross
AVIATION...Gibbs
Area Forecast Discussion
National Weather Service Jacksonville FL
914 PM EST Sat Jan 22 2022
...INLAND FREEZE TONIGHT...
.UPDATE...
Latest satellite imagery shows widespread low clouds continuing
with ceilings mainly in the 500-1000 ft range. The guidance has
been too quick to let up on the clouds and the imagery and
guidance suggested to keep more of the area in the clouds
overnight. This will have affects on the eventual low temps with
some uncertainty on the min temps mostly over the srn zones where
the clouds will likely linger the longest, and some of the
guidance has hinted at low temps slightly warmer than prior
forecast. The 00Z JAX sounding shows warming in the lowest layers
but cold advection just above the cloud deck, indicating a
a pattern of erosion of the low clouds at least around the JAX
metro area. For the update, mainly just refreshed the temps and
increase the sky cover rest of tonight. Otherwise, the freeze
warning remains up but may not be as cold in some areas due to the
lingering clouds. Of note too for today, we have broken the
record low maximum temperatures at the following local climate
sites: Alma, Craig Airport, Jacksonville Intl Airport, and
Gainesville.
.MARINE...
Current forecast was on track with little change. SCA remain
intact for most of the area waters.
&&
.PREV DISCUSSION [659 PM EST]...
.NEAR TERM [Through Tonight]...
Observed temperatures this afternoon/evening are trending colder
than the forecast temperatures due to a persistent deck of low
stratus over the entire area, and we could set records for coldest
maximum temperatures for this day (see climate section). Overcast
skies are expected to continue through this evening for most of
the area, then cloudiness will begin to decrease from north to
south throughout the night. Northerly winds will become calm over
SE GA and the Suwannee Valley tonight, which will allow surface
low temperatures to drop into the upper 20s. Areas generally from
Amelia Island to Gainesville will also see cold low temperatures
in the lower 30s. A Freeze Warning has been issued for areas
where lows will be at or below freezing tonight, and widespread
frost will be possible in this area as well. Cloud cover will
linger longer and winds won`t be as calm over N central FL and
along the NE FL coast, so low temperatures will be slightly warmer
in the middle 30s. Patchy frost will be possible in N central FL
and in rural areas of coastal counties in NE FL, but winds and
cloud cover are expected to prevent frost from becoming
widespread.
.SHORT TERM [Sunday Through Monday Night]...
High pressure will be centered to our west on Sunday with the
ridge axis extending over the area, then the high is expected to
shift directly over the area on Monday. West-northwesterly winds
will prevail on Sunday, then winds will become calm across the
entire area on Monday. Dry weather is expected both days with
clear skies Sunday and mostly clear skies on Monday.
Temperatures on Sunday will be warmer than they were today during
the day, but clear skies and calming winds will lead to another
cold night. Sunday high temperatures will be in the 50s area-
wide, and Sunday low temperatures will be in the upper 20s to
lower 30s inland and middle 30s at the coasts. A Freeze Watch has
been issued for late Sunday night into Monday morning for all of
SE GA and inland NE FL where lows are expected to be at or below
freezing. Widespread inland frost is expected as well.
Temperatures will increase on Monday with highs in the upper 50s
to lower 60s and lows in the upper 30s to lower 40s.
.LONG TERM [Tuesday Through Saturday]...
An upper level cutoff low moving over the southern US is expected
to spawn a surface low over the northern Gulf of Mexico that will
track across the Florida peninsula on Tuesday. Scattered showers
are expected to start over our western zones during the early
morning hours on Tuesday, and showers are expected to become
widespread in the afternoon. The low will exit into the Atlantic
Tuesday night, and showers will come to an end by Wednesday
morning.
High pressure will build to the northwest on Wednesday,
then to the north and northeast on Thursday. Coastal troughing is
expected to develop Thursday into Friday that could produce
coastal showers. Next weekend, an upper level shortwave trough is
expected to dive south towards the Southeast US and could bring
another low pressure system across the area. However, there is
quite a bit uncertainty in the forecast this far out due to large
difference in model solutions. The GFS brings a low across the
area with widespread showers, but the ECMWF only brings a few
showers to our area and spawns the low off the Mid-Atlantic
coast.
.AVIATION...
[Through 00Z Monday]
At 00Z, IFR ceilings continues at all sites except for SSI where
it went to MVFR a few hours ago. LIFR ceilings are stubborn to
improve at SGJ which is not addressed in most of model guidance.
The LIFR/IFR conditions for the northeast FL TAFs look to, more
or less, continue through the night though some temporary
improvements are possible later tonight for JAX and CRG but it
appears that ceilings could lower again toward the 07Z-10Z time
frame. We can`t rule out a short window of LIFR ceilings for GNV
later tonight based on NBM guidance. We should still see gradual
improvement Sunday morning but have pushed back the MVFR and VFR a
bit later based on HRRR and NAM guidance and VFR conditions
expected to develop at TAF sites in the 15Z-18Z Sunday time frame.
North-northwest winds decrease tonight through Sunday morning,
with winds turning more northwest to west at 5-10 kt Sunday
afternoon.
.MARINE...
High pressure will be to the west through Sunday, then shift over
the area on Monday. Winds and seas will remain elevated through
Sunday, but conditions will relax on Monday. Small Craft
Advisories are in effect through Sunday. A low pressure system is
expected to form over the northern Gulf of Mexico and move across
the local waters late on Tuesday. The low will exit to the
northeast on Wednesday, then high pressure will build to the north
and northeast on Thursday.
Rip Currents: High risk today at NE FL beaches, moderate risk
today at SE GA beaches. Moderate risk at all area beaches Sunday.
.FIRE WEATHER...
High pressure to the west-northwest will gradually shift over
the area through Monday with dry weather expected Sunday and
Monday. Northerly winds tonight will shift to westerly Sunday.
Light transport winds will result in lower daytime dispersions
for NE FL on Sunday, values will be in the 20-30 range with
lower dispersions closer to the Gulf coast. Transport winds
will become weak on Monday, resulting in low daytime
dispersions below 20 for most of NE FL. Significant fog not
expected. Cold temperatures expected tonight and Sunday night,
freeze and frost conditions expected for most of the area.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 27 54 30 58 38 / 0 0 0 0 20
SSI 32 53 35 58 43 / 0 0 0 0 20
JAX 31 55 32 60 41 / 0 0 0 0 20
SGJ 36 56 35 60 44 / 0 0 0 0 20
GNV 32 56 30 61 39 / 0 0 0 0 20
OCF 35 58 30 63 40 / 0 0 0 0 20
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...Freeze Watch from late Sunday night through Monday morning for
Baker-Bradford-Central Marion-Eastern Alachua-Eastern Clay-
Eastern Marion-Eastern Putnam-Gilchrist-Hamilton-Inland
Nassau-Northern Columbia-Southern Columbia-Suwannee-Trout
River-Union-Western Alachua-Western Clay-Western Duval-
Western Marion-Western Putnam.
Freeze Warning from 1 AM to 9 AM EST Sunday for Baker-Bradford-
Coastal Nassau-Eastern Alachua-Eastern Clay-Gilchrist-
Hamilton-Inland Nassau-Northern Columbia-Southern Columbia-
Suwannee-Trout River-Union-Western Alachua-Western Clay-
Western Duval-Western Putnam.
GA...Freeze Watch from late Sunday night through Monday morning for
Appling-Atkinson-Bacon-Brantley-Clinch-Coastal Camden-
Coastal Glynn-Coffee-Echols-Inland Camden-Inland Glynn-Jeff
Davis-Northeastern Charlton-Northern Ware-Pierce-Southern
Ware-Wayne-Western Charlton.
Freeze Warning from 1 AM to 9 AM EST Sunday for Appling-Atkinson-
Bacon-Brantley-Clinch-Coastal Camden-Coastal Glynn-Coffee-
Echols-Inland Camden-Inland Glynn-Jeff Davis-Northeastern
Charlton-Northern Ware-Pierce-Southern Ware-Wayne-Western
Charlton.
AM...Small Craft Advisory until 7 PM EST Sunday for Waters from
Fernandina Beach to St. Augustine FL from 20 to 60 NM-
Waters from St. Augustine to Flagler Beach FL from 20 to 60
NM.
Small Craft Advisory until 9 AM EST Sunday for Coastal waters
from Fernandina Beach to St. Augustine FL out 20 NM-Coastal
waters from St. Augustine to Flagler Beach FL out 20 NM-
Waters from Altamaha Sound GA to Fernandina Beach FL from
20 to 60 NM.
&&
AREA FORECAST DISCUSSION
National Weather Service Jackson KY
928 PM EST Sat Jan 22 2022
.UPDATE...
Issued at 925 PM EST SAT JAN 22 2022
Only minor updates to the near term forecast. A weak impulse
moving through the area this evening is resulting in a thin band a
lower stratus crossing the area from NW to SE. Also made minor
tweaks to temps based on current trends. Otherwise, forecast
remains on track. Updates sent to NDFD and web servers.
&&
.SHORT TERM...(This evening through Sunday night)
Issued at 332 PM EST SAT JAN 22 2022
It has been a fair but chilly afternoon with 20z temperatures
running in the upper 20s and low 30s. Have tweaked grids slightly as
forecast temperatures were running a few degrees behind. Looking
regionally, surface high pressure is in control across the Southern
Plains and Lower Mississippi Valley this afternoon. To our north, an
upper level longwave trough is placed across Eastern Canada,
supporting a surface low just north of the Great Lakes. A cold front
will run just east of Montreal, bending back across the state and
through Southern Missouri near 12z Sunday, breaking back north in
the form of a warm front tomorrow afternoon. An approaching cold
front will then take shape across the Upper Mississippi Valley,
sliding east into the evening and bringing a slight opportunity for
PoPs. This quick moving clipper is expected to pass through to
our north, doing just that, clipping portions of Eastern Kentucky.
With very low QPF associated and fairly dry mid levels initially,
anticipate little in the way of precipitation for all but our far
northern counties and the high terrain late Sunday evening. Hi-
Res guidance, namely the HRRR and Nest are a bit more aggressive,
suggesting both PoPs making it a bit further south and higher QPF,
but am not so inclined to agree given ensemble runs, sounding
profiles, and other Hi-Res members. With that said, will see the
increase of cloud cover across the CWA into Sunday morning and
through the day, with flurries during the morning and sprinkles in
the afternoon possible for mainly the northern half of the CWA.
Additionally, a SW to NE oriented LLJ will cross the CWA during
the morning to mid afternoon. 850mb winds are between 35-45 kts
and any momentum transfer down to the surface could produce gusts
up to 20- 25 mph. Dry conditions then return for the start of the
new work week.
Sensible weather through the short will be fairly quiet. Flurries in
our farthest north counties are possible into the morning tomorrow,
eventually changing over to isolated to scattered rain showers. With
some upslope flow taking place into the evening and overnight
tomorrow, could see lingering stratus and the opportunity for light
snow showers/flurries in the high terrain bordering Virginia.
Temperature-wise, another chilly night is on tap with valleys
bottoming out in the mid teens and ridges in the upper teens to low
20s. Temperatures will continue rebounding for the end of the
weekend topping out in the upper 30s (in the north) and mid 40s (in
the south). With a bit more cloud coverage overnight Sunday,
ridge/valley splits won`t be as pronounced, ranging from the mid
teens for the Bluegrass and lower 20s in the southeast.
.LONG TERM...(Monday through Saturday)
Issued at 251 PM EST SAT JAN 22 2022
Monday starts quiet but transitions to a potentially active period
late Monday night into Tuesday. There`s a lot of variability on the
events for Tuesday and none of the models are lining up to present
any sort of consensus or clear-cut solution. With that being said,
currently leaning for a middle ground approach which is the NBM
solution as the NAM is too aggressive and the GFS/ECMWF is not
aggressive enough. Nonetheless, if any precipitation occurs it`ll be
light snow showers or light rain/snow showers with little to no
accumulations except or higher elevations in relationship to upslope
snow showers in the eastern mountains.
Moderately weak ridging/zonal flow builds in behind Tuesday`s event
keeping slightly below average temperatures overhead through the
remainder of the week. Downstream attention turns toward the end of
the period as somewhat decent model consensus exists for an end of
the week winter system bringing widespread PoP to the Ohio Valley.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
ISSUED AT 610 PM EST SAT JAN 22 2022
VFR to start the 00Z TAF period. SCT to BKN ceilings around 4k ft
will pass across SYM early in the period, otherwise mainly FEW
high clouds across eastern KY this evening. Winds will be light
and variable tonight and overnight, then become SW 5-10 kts with
gusts of 15-20 kts during the day on Sunday, becoming westerly
towards the end of the period. Some MVFR ceilings will drop down
ahead of a cold front late Sunday afternoon into early evening,
most likely to impact SYM during this TAF cycle.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...CMF
SHORT TERM...BB
LONG TERM...VORST
AVIATION...CMF
Area Forecast Discussion
National Weather Service Pendleton OR
749 PM PST Sat Jan 22 2022
.UPDATE...Fog and stratus clouds are blanketing portions of the
Lower Columbia Basin, Blue Mtn Foothills, and the eastern Columbia
River Gorge this evening with dense fog along the Blue Mtn
Foothills. Current Freezing Fog Advisories for the Basin and
Foothills look good, and there are no plans to extend to other
forecast zones at this time. The southern end of the Yakima Valley
has the best potential for dense fog where dewpoint spreads are
currently around 2-3 degrees, but the north end of the valley has
about an 8 degree spread at this time. The HRRR has been quite
impressive this evening showing the fog making its way into
Prosser and Sunnyside which the night fog on GOES-17 is showing.
High pressure aloft with the center of the upper level ridge off
the coast will remain stationary through Sunday afternoon. Strong
low and mid level inversions have developed, and surrounding RAOB
sites at BOI, MFR, SLE and OTX show the top of the mid level
inversion around 12K-15K feet. A strong stable air mass along with
weak winds aloft have created poor ventilation and limited mixing.
There will be some improvement in the mixing Sunday night when a
shortwave trough moves south from Canada and across the PacNW.
There is very little impact on the forecast area except to bring
gusty winds in the Grande Ronde Valley where gusts 30-40 mph are
expected south of La Grande. Pressure gradients will tighten and
thermal gradients from the colder Baker Valley to the Grande Ronde
Valley will be fairly significant. Otherwise, the fog and stratus
may lift some in and around the Columbia Basin. Wister/85
&&
.PREV DISCUSSION... /issued 221 PM PST Sat Jan 22 2022/
SHORT TERM...Tonight through Tuesday...Strong high pressure
aloft just off the coast will remain in place for the next few
days. There is one shortwave trough that will drop sewd across the
region on the eastern periphery of the high Sunday night and
Monday. The main weather concern through the short term is the
potential for freezing fog and low clouds. Have just issued a
freezing fog advisory for the Columbia Basin and the northern
foothills of Oregon and SE Washington through 1 pm Sunday. The fog
is hanging around this afternoon longer than earlier anticipated
and think once the sun sets it will only expand and visibilities
will deteriorate. The HRRR visibility forecast shows rather low
visibilities overnight into Sunday morning. Other areas of concern
are the Yakima and Kittitas Valleys but will let subsequent
shifts monitor visibility trends since confidence is not
sufficient to issue fog highlights at this time. On Sunday the
pressure gradient in the southern Grande Ronde Valley tightens a
bit and this will lead to at least breezy winds in Ladd and Pyles
Canyons. Latest pressure difference forecast between Ontario and
Meacham from the NAM is 7.7 mb Sunday evening which is weaker than
previous model runs so confidence that wind highlights will be
needed is low. At least patchy fog and low stratus will continue
into Tuesday which will keep the lower elevations cold compared
to the mountains where temperatures will be above normal. 78
LONG TERM...Tuesday Night through Saturday...Models continue to
show general agreement in having a ridge off the west coast though
they have differences about passing weak shortwaves that become more
pronounced by Friday. Ensemble analysis shows the deterministic runs
are well positioned towards the average of their ensembles but the
model ensembles are clearly in different camps which affects overall
confidence later in the week. A quiet period with low clouds and fog
is expected in the Columbia Basin and adjacent lower valleys through
Friday with mostly clear skies elsewhere. Conditions in the Columbia
Basin are expected to improve on Friday though confidence in this
isn`t high. Tuesday night the ridge axis will be offshore but the
GFS has a moderately strong wave moving over the ridge while the
Canadian has a weaker wave. The ECMWF has a barely perceptible wave.
Even the GFS wave will do little more than provide a brief mixing
out of the Columbia Basin low clouds and fog. Thursday and Thursday
night models have the ridge axis overhead, so am expecting the low
clouds and fog to persist with mostly clear skies elsewhere. Friday
and Friday Night, the ECMWF brings a trough through the area while
the Canadian brings a weaker trough through about 6-12 hours later.
The GFS shows a weak wave riding over the ridge mainly into British
Columbia. Have leaned towards the ECMWF and Canadian with a chance
of snow in the Cascades Friday through Saturday with a slight chance
of snow in the eastern Oregon mountains on Saturday. At this point,
mountain snow amounts look to be light and generally less than an
inch. Temperatures under the fog and low clouds will be in the lower
to mid 30s while elsewhere temperatures will be in the 40s to lower
50s. Winds will be light aside from some 10 to 20 mph winds in the
Grande Ronde Valley on Wednesday and again on Friday and Saturday. 83
AVIATION...00Z TAFs...High pressure will provide generally clear
skies over much of the area for the next 24 hours aside from some
high cirrus. However, low clouds and fog have developed today in the
Columbia Basin and with high pressure remaining in place, am
expecting the low clouds and fog to increase in intensity and
coverage. ALW is expected to remain at LIFR CIGs and visibility for
the next 24 hours with brief MVFR conditions for a few hours around
00Z. PSC will likely also see LIFR conditions return after 05Z as
will PDT and DLS after 09Z. YKM will have low stratus and MVFR/IFR
CIGs and visibilities are expected there. DLS, YKM, PDT and perhaps
PSC will see some improvement after 18Z-21Z tomorrow afternoon. RDM
and BDN are expected to remain at VFR for the next 24 hours. Winds
will remain under 10 KTS for the next 24 hours. 83
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 26 30 25 32 / 0 0 0 0
ALW 28 34 27 33 / 0 0 0 0
PSC 27 34 26 36 / 0 0 0 0
YKM 21 37 24 39 / 0 0 0 0
HRI 26 34 27 37 / 0 0 0 0
ELN 22 36 23 41 / 0 0 0 0
RDM 27 53 27 56 / 0 0 0 0
LGD 23 41 24 42 / 0 0 0 0
GCD 26 49 29 48 / 0 0 0 0
DLS 30 40 29 42 / 0 0 0 0
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...Freezing Fog Advisory until 1 PM PST Sunday for ORZ044-507.
WA...Freezing Fog Advisory until 1 PM PST Sunday for WAZ028-029.
&&
$$
UPDATE...85
SHORT TERM...78
LONG TERM....83
AVIATION...83
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