Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 09/10/22
Area Forecast Discussion
National Weather Service Binghamton NY
935 PM EDT Fri Sep 9 2022
Above average temperatures are expected today and Saturday
under partly to mostly sunny skies. The next system moves in
Sunday, with increasing cloud cover, falling temperatures, and
chances for showers. Rain shower chances continue into early
.NEAR TERM /THROUGH SATURDAY/...
Skies have cleared now that the sun is down and heating has
subsided. This is expected to continue through the overnight
hours before scattered clouds begin to work their way back into
the area from the southwest Saturday morning and thicken up by
the late afternoon ahead of the next low pressure system.
Tonight, temperatures will drop to the mid to upper 50s with a
few sheltered spots may dip into the low 50s. Highs on Saturday
will be a few degrees warmer than today as SW flow returns to
the area. Expect the low to mid 80s across the valleys with
upper 70s at higher elevations.
630 PM Update...
Another look was given to the overnight temperatures to see if
radiational cooling might knock temps down a few degrees lower
than guidance. It looks like winds just above the surface will
pick up later this evening, allowing for mixing to occur
overnight and counteract the effects of radiational cooling from
a clear sky. Because of this, lows were not adjusted from the
afternoon forecast package.
The forecast remains on track.
230 PM Update...
Sunny skies will be present the rest of this afternoon. However,
the sky may not look as blue as a typical clear day as elevated
smoke from wildfires out west sits over the region. This smoke
will remain elevated and is not expected to have any impacts to
conditions at the surface. HRRR smoke shows that this smoke will
hang around until late tonight.
A ridge of high pressure will be present over the region for
this period, resulting in dry conditions until late Saturday
night/early Sunday morning. After reaching the upper 70s to mid
80s this afternoon, temperatures will fall into the 50s and low
60s overnight. Other than the aforementioned elevated smoke,
skies will be clear. Fog that develops tonight should remain in
the valleys and not spread out like it did last night.
Visibilities will be reduced though where fog develops.
Fog clears out a couple hours after sunrise with sunny skies
expected through the morning hours. Southwest flow will advect
moist air into the region, and high clouds move in during the
afternoon, resulting in partly sunny skies. Temperatures will be
around the same as today, upper 70s to mid 80s. Heading into
the overnight, a shortwave moves up the ridge and will bring a
chance for showers to the western portions of the Twin Tiers and
Wyoming Valley after midnight. There are some timing
differences between model guidance and the arrival of these
showers, so the NBM and HREF were followed for PoPs. Sky cover
also increases ahead of this shortwave, leading to mostly cloudy
skies. Temperatures Saturday night will be slightly warmer,
only falling into the upper 50s to mid 60s.
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
230 PM Update...
Main concerns in the short term are focused on the potential
for rain Sunday and another round of showers and storms Monday.
A large area of low pressure over the Northern Plains will start off
as an open wave Saturday night and slowly rotate to the east through
the Midwest and Great Lakes Sunday into Monday...becoming cutoff
from the primary synoptic flow. This storm system will be able to
draw a deep layer of moisture across the mid Atlantic region
into parts of the Northeast on Sunday. The increasing moisture
and overall warm advection regime will cause cloud cover to
increase rapidly early Sunday morning. Rain is expected to
develop to the south and gradually spread north through the day.
The axis of highest PW values nudging in from the south will
top out around 1.75 to 2 inches...which is roughly 1-2 standard
deviations above normal. This rich and humid air mass will allow
for some efficient rainfall during the day Sunday and into
Sunday evening before the ribbon of moisture moves off the
coast. The stronger dynamical forcing will remain closer to the
upper low to the west and instability will be limited as well,
so conditions will only be marginal for heavy rainfall on
Sunday. Much of the region will likely see scattered showers on
and off through the day and into the evening hours. Highs in the
afternoon will top out in the 70s...and then only drop only
into the upper 50s and 60s Sunday night given the amount of
cloud cover persisting into Monday morning.
The upper low will be approaching from the west Monday morning and
move into the IN/OH area by Monday afternoon. A secondary warm front
will lift north across the mid Atlantic on Monday, which will allow
for strong layer lifting over PA and into NY. The deepest moisture
will still be centered off the coast, but stronger forcing from the
approaching upper low and jet streak rounding the base of the low
will provide the necessary ingredients for another round of showers
through the day. There will also be a weak to moderate amount of
instability present by Monday afternoon which will help generate
convection and scattered thunderstorms. Deep layer shear is expected
to hold off to the w/sw on Monday...so storms are not expected to be
severe at this time, but some heavy downpours are not out of the
question. High temperatures are expected to rise into the mid to
upper 70s close to 80 around Syracuse and Scranton on Monday.
.LONG TERM /TUESDAY THROUGH FRIDAY/...
230 PM update...
The cutoff low over Ohio Monday evening will speed up and lift to
the northeast across the eastern Great Lakes into southern Quebec by
late Tuesday/early Wednesday. As this occurs scattered rain showers
are possible across much of the region...especially Monday night
through Tuesday evening on the front end of the system and as it
passes through. The cold air at the center of the upper low as it
moves across central NY/ne PA should cause steep low/mid level lapse
rates to become favorable for isolated thunderstorms. Severe weather
is not expected. Then, on the back side of the system, a drier and
cooler air mass will settle in with some lake enhanced showers
firing off downstream of Lake Ontario into Wednesday. High pressure
really starts to dominate the region by Thursday with skies clearing
off and temperatures rebounding.
Highs on Tuesday should be able to climb into the mid to upper 70s,
but with the cooler air sliding in from the west/nw, lows Tue night
may fall into the lower to mid 50s. A bit more sun on Wednesday
should bring temperatures back into the 70s once again, but with
much lower humidity expected. Wed night may be the coolest night
with lows dropping into the upper 40s in some higher elevations and
lower to mid 50s for most other areas.
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
Mostly VFR conditions are expected through the period, however fog
will likely develop at ELM and RME overnight into early Saturday
morning. Any fog will bring IFR restrictions through Saturday
morning until an hour or two after sunrise.
Otherwise, skies will be mostly clear with some mid-level
cumulus over the region during the afternoon and some high
clouds also move in from the south tomorrow evening ahead of
the next system.
Saturday night...Mainly VFR.
Sunday through Tuesday...Chance for rain showers and associated
restrictions. Afternoon thunderstorms will be possible Monday
and Tuesday afternoon.
Wednesday...Lingering showers for SYR and RME Wednesday morning.
Otherwise, mainly VFR.
Area Forecast Discussion
National Weather Service Boise ID
913 PM MDT Fri Sep 9 2022
.DISCUSSION...An upper level ridge will rebuild over the region
over the short term. With slightly warmer temperatures possible,
smoke may keep temperatures a few degrees lower than forecast.
Smoky conditions will continue over the next several days with
little change expected.
.AVIATION...Smoke reducing visibility. Surface winds: variable 10 kt
or less becoming E-SE 10-15 kt Saturday. Winds aloft at 10k feet
MSL: NW 10-20 kt, decreasing to 5-15 kt Saturday.
Sunday Outlook...Smoke reducing visibility. Surface winds variable
10 kt or less, becoming E-SE 5-15 kt in the afternoon.
.AIR STAGNATION...Smoky conditions will continue over the next
several days with little change expected. Some improvement may
come early next week as shower chances increase.
SHORT TERM...Tonight through Sunday night...Today`s cool surface
air mass and supporting upper trough will move off to the east
tonight as an upper ridge approaches from the Pacific. This will
lead to a warming trend that will peak on Sunday when the ridge
passes overhead. Smoke from wildfires has become thick enough to
require an Air Quality Advisory from the Idaho Department of
Environmental Quality. The Advisory will last through 3 PM MDT
Monday. With the HRRR smoke model showing smoke persisting under
the incoming upper ridge, it is likely that all areas will remain
smoky all the way through, thickest in northern parts of our CWA.
Already the smoke is thick enough to lower daytime temperatures
and we have lowered our forecast highs for both Saturday and
Sunday about 1 degree in the south to 3 degrees in the north.
Northwesterly surface winds today will become light to locally
moderate easterly Saturday as a surface high pressure area moves
to our east while a surface thermal trough forms to our west. On
Sunday the surface thermal trough will be right over our CWA with
light winds converging into it from the east and west. Moisture
from Hurricane Kay off northern Baja California will work
northward this weekend, reaching southern Harney and southern
Malheur Counties early Monday morning. Clouds will increase in
those counties but the rest of our CWA should stay clear, but
smoky, through Sunday night.
LONG TERM...Monday through Friday...The ridge from the weekend
will continue to slide east through Idaho on Monday, allowing
additional south to southwest flow over the region. Moisture
remnants from Tropical Cyclone Kay are anticipated to move over
the forecast area on Monday. Influence and coverage of this
moisture will be influenced by a presence of a trough, which could
limit shower presence. Confidence on development of showers on
Monday is not overly high. The wave associated with the inland
remnants of Kay will lift across the area on Tuesday, which looks
to be another day of a challenged forecast. The speed of this
trough varies per model, again influencing moisture location and
intensity across the forecast area. Following this system, another
wave of low pressure along the Pacific coast will move into the
Pacific Northwest later in the week, after Wednesday and
potentially as late as Thursday. Timing and resulting moisture
will depend on the final track of this system. Potentially drier
conditions anticipated Friday after the departure of that later
trough. Overall, the long term forecast looks to have periods of
showers and thunderstorms, with thunderstorm coverage mainly
anticipated on and after Tuesday. Temperatures across the region
will return to near normal on Tuesday, with values cooling to
below normal by Thursday.
ID...Fire Weather Watch from Sunday afternoon through Sunday evening
PREV SHORT TERM...LC
PREV LONG TERM....KB
Area Forecast Discussion
National Weather Service Boston/Norton MA
1015 PM EDT Fri Sep 9 2022
High pressure will continue to dominate our weather through this
weekend with dry weather and seasonable late summer temperatures,
although we will see a milky haze from wildfire smoke aloft. In
addition, swells from distant Hurricane Earl will bring rough
surf and a high risk of rip currents at the ocean beaches. Our
weather will turn wet early next week with showers and
thunderstorms at times.
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
No major changes to the ongoing forecast this evening. Did tweak
temperatures overnight to reflect observed trends.
745 PM Update:
Forecast looks to be in great shape with no significant change
needed at this time.
High pressure established across Southern New England with clear
skies, a dry air mass and light to calm winds. Sets the stage
for strong radiational cooling now that the sun has set. As
noted earlier, little to no lower level moisture evident in
model forecast soundings supports mainly clear weather for many
except at times in the river valleys late in the overnight.
Lows look on track with no changes needed there as well.
Satellite loop shows clear skies throughout SNE this afternoon
as high pressure remains in control. We may see some diurnal
cumulus form near some of the higher terrain until sunset, but
that`s about it. Starting to see some evidence of western
wildfire smoke on GOES-16 Airmass RGB making its way into
southern Canada and approaching the Northeast, much like HRRR
forecasts indicate. It`s possible we may be in for a reddish
sunset tonight and especially during sunrise Saturday.
Otherwise, we`re in for another night of ideal radiational
cooling conditions with a dry airmass, clear skies, and light
winds. Model cross sections don`t show a lot of lower level
moisture than they have past few nights, so any fog/low clouds
should be fairly localized and limited to interior valleys.
Sided with cooler MOS guidance for lows tonight, mainly
in 50s to lower 60s.
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
100 PM Update:
* High surf/dangerous rip currents Saturday at ocean beaches
For those planning a trip to the beach Saturday, be aware that
we expect high surf and dangerous rip currents at ocean beaches
(both South Coast/Islands and on the North Shore). Remember
that most beaches are no longer staffed with lifeguards for the
season since we are now past Labor Day. It will also be
dangerous to view the surf from jetties or the coastline, so be
sure to stay a safe distance away! It`s quite possible an
elevated rip current threat will persist Sunday too.
A High Surf Advisory remains posted Saturday for the ocean
beaches along south coast of RI and MA, including Cape Cod and
the Islands. Offshore buoys are reporting long period swells of
7+ ft, from combination of low pressure over North Atlantic and
some contribution from distant Hurricane Earl. These swells are
expected to peak early Saturday morning and will bring rough
surf and dangerous rip currents to ocean beaches. We added the
North Shore as well (coastal Essex County) for Saturday since
model wave guidance pushes these higher SE swells westward
toward Cape Ann during the day. Areas from Boston south to
Plymouth County should be spared of these higher swells due to
shadowing effects from the Cape.
Otherwise, high pressure will bring another day of sunshine and
slightly warmer temperatures (80s), except along immediate coast
where sea breezes will keep it a little cooler. Saturday night
will be another night of clear skies and light winds, but
slightly higher dewpoints means low temperatures will run a
little milder, mainly in 60s.
.LONG TERM /SUNDAY THROUGH FRIDAY/...
* Increasing clouds but continued dry for Sunday. Rip currents
due to swell from distant Hurricane Earl may continue to
affect the coastlines.
* Unsettled Mon and Tues with showers and embedded t-storms.
While severe weather not anticipated, could have localized
downpours. Temps cool to more seasonable levels.
* Drier weather returns for mid to late week with cooler than
normal temperatures for late Sept.
Deep layer ridge remains established across SNE early on Sunday,
but recent runs in guidance shows a tendency to weaken the ridge
sooner than prior indications. Per model forecast soundings this
doesn`t translate to rain chances on Sunday, with a good amount
of unsaturated air below 500-600 mb. Shown mostly cloudy skies
but a lot of this cloudiness should be of the mid- level cloud
type with dry weather for the daytime hrs. Clouds continue to
increase Sunday evening as ridge axis shifts eastward, allowing
for rising moisture levels and some mid/upper level support for
increasing rain chances across western MA/CT. Cooler highs in
the mid 70s to around 80 for the western interior areas and
along the immediate coastline, with warmer mid-80s highs in the
coastal plain. Lows mainly low to mid 60s with an uptick in
Note that we may still have some lingering swell from distant
Hurricane Earl that could continue a risk for rip currents into
Sunday; though it won`t necessarily be a great beach day (at
least compared to Sat) but keeping awareness high as beaches
become less staffed with lifeguards in the post Labor Day
Monday through Tuesday Night:
Still anticipating a couple days of wet weather as a plume of
elevated PWAT values (1.5-1.7" / 1.5-2 standard deviations
above normal for mid-Sept) interacts with height falls
associated with a closed but gradually deamplifying low across
the Gt Lakes. Some instability is noted in some models, most
bullishly in the NAM with CAPE with about 800-1000 J/kg. In
addition, in conjunction with the high PWAT values we do also
see warm cloud depths in the 12kft to 13kft range favorable for
efficient downpours through warm rain microphysical processes.
Probably won`t see severe weather given modest to borderline-
supportive vertical wind profiles; these profiles also are
strong enough from a storm-motion perspective to keep
showers/embedded storms moving. Kept PoP at high chance to low
likely for now but could see a need to increase these in coming
day pending continued consistency in subsequent guidance. Closed
low deamplifies Tue night as it moves NE into northern New
England, swinging a cold front through SNE Tue night into early
Wed AM, tapering off rain chances.
Temperatures trend cooler than normal on the highs (mid 70s-near
80) owing to cloudiness/rain and reduced sunshine but milder
than normal low (mid 60s) due to the same influences at night.
Wednesday through Thursday Night:
Other than some spotty light rain showers across northern MA,
many areas are generally dry. While dry weather prevails, a shot
of colder air (850 mb temps in the mid to upper single digits C)
and high pres in control, it could support some cool nights with
much lower humidity in this period. Highs also look to trend
cooler than normal, in the mid to upper 70s.
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
Forecaster Confidence Levels:
Low - less than 30 percent.
Medium - 30 to 60 percent.
High - greater than 60 percent.
VFR through Saturday night. Expect some localized MVFR/IFR in
patchy valley fog tonight and again Saturday night, but it
should be less widespread than past few mornings. Light winds
will allow for coastal sea breezes Saturday.
KBOS Terminal...High confidence in TAF.
KBDL Terminal...High confidence in TAF.
Outlook /Sunday through Wednesday/...
Saturday Night through Sunday Night: VFR.
Monday: Mainly VFR, with local MVFR possible. Chance SHRA.
Monday Night: Mainly VFR, with local IFR possible. SHRA likely.
Tuesday: Mainly VFR, with local IFR possible. Breezy. Chance
Forecaster Confidence Levels:
Low - less than 30 percent.
Medium - 30 to 60 percent.
High - greater than 60 percent.
100 PM Update: High confidence.
High pressure will remain over waters through Saturday night. NE
winds will diminish tonight, followed by lighter winds and
coastal sea breezes Saturday, then light southerly winds
SCAs remain posted for rough seas on outer waters and for
RI/Block Island Sounds. Seas peak Saturday morning, mainly due
to SE swell, and begin to subside Saturday night.
Please refer to the discussion on High Surf Advisories in Short
Term section above.
Outlook /Sunday through Wednesday/...
Saturday Night: Winds less than 25 kt. Local rough seas.
Sunday through Sunday Night: Winds less than 25 kt. Seas up to
Monday: Winds less than 25 kt. Areas of seas approaching 5 ft.
Slight chance of rain showers.
Monday Night through Tuesday: Winds less than 25 kt. Seas
locally approaching 5 ft. Chance of rain showers.
MA...High Surf Advisory from 6 AM to 6 PM EDT Saturday for MAZ007.
High Surf Advisory until 6 PM EDT Saturday for MAZ020-022>024.
RI...High Surf Advisory until 6 PM EDT Saturday for RIZ006>008.
MARINE...Small Craft Advisory until 8 AM EDT Saturday for ANZ232.
Small Craft Advisory until 6 PM EDT Saturday for ANZ235-237.
Small Craft Advisory until 8 AM EDT Sunday for ANZ250-254>256.
Area Forecast Discussion
National Weather Service Caribou ME
936 PM EDT Fri Sep 9 2022
High pressure will prevail tonight through the weekend. A weak
cold front will stall north of Maine Monday. Low pressure from
the west will approach Tuesday and move over the area Wednesday.
.NEAR TERM /THROUGH SATURDAY NIGHT/...
928 PM update...Dropped overnight lows a degree in two in line
with trends from recent nights. With the longer nights this time
of year and dew points in the upper 50s to lower 60s, areas of
fog appear destined to form again after midnight in river
valleys under a steep and shallow radiation inversion. The other
item of interest for Saturday besides unseasonably warm and
humid conditions will be smoke. Smoke from western fires is
expected to create hazy conditions throughout Saturday based on
METSAT trends and HRRR guidance. The smoke is above 5000 feet.
High pressure will remain over the region for tonight and
Saturday, making for clear skies and calm winds. For tonight,
HREF and SREF models indicate another round of valley and river
fog in the late hours. Some higher terrains could see
encroaching patchy fog in the early morning hours on Saturday.
The warm airmass at 925mb will stick around the area through
tonight with temps around 18C. This with the thin layer of mid
level clouds push temps into the upper 50s tonight. By Saturday,
ample sunshine after the initial morning fog. Once that burns
off, sun and the warm airmass will push temps to above average
values for this time of year. Expect highs in the low 80s with
calm winds. For Coastal Downeast, the very distant Hurricane
Earl will affect seas on Saturday, creating 13-15 second swell,
which will generate some dangerous waves along the coast. A High
Surf Advisory has been issued beginning in the early morning
Saturday and ending late Saturday evening.
.SHORT TERM /SUNDAY/...
H5 ridge will be firmly entrenched over the CWA on Sunday. With high
pressure at the surface accompanied by clear skies and light winds
another round of river valley fog is expected Sat night into Sun
morning. High cirrus will move into fm the west shortly after
daybreak and spread east during the day. However expect cirrus will
be thin enuf drg the day to have little impact on temps with highs
well into the 80s over inland locations. Temps wl obviously be
cooler where fog tends to hang on longer in the morning.
Cold front will be dropping south thru Quebec drg the day before
slowing down and essentially weakening in place btwn 06-12z Monday
to the north of the border. This wl result in cloudy skies and
should prevent valley fog fm developing Sun night along with warmer
min temps Mon morning.
With boundary lurking acrs the north cannot rule out an isold shower
developing over the St. John Valley in the afternoon. GFS indicates
a fairly potent s/wv moving thru the state drg the afternoon but
rmng operational runs do not indicate this, including it`s ensemble
mean and have discounted this soln.
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
Our focus Monday night into Tuesday will be on an upper low lifting
out of the Great Lakes and toward the Northeast. The upper low will
cross into the southern Great Lakes Monday night as a weak surface
low and occlusion approaches the Mid-Atlantic coast. Moisture
lifting north ahead of the occlusion will bring increasing clouds
Monday night. The occlusion will begin to push into our region on
Tuesday as the upper low slides into the eastern Great Lakes. This
will likely bring showers late Tuesday into Tuesday night. Both the
GFS and ECMWF indicate there may be some mid level convection
supported by humid air advecting north beneath upper level
divergence and cooling associated with the approach of the upper
low. This could make rainfall amounts quite variable across the area
with widespread light to moderate rain and locally heavier rain
where the convection sets up. Showers will continue Tuesday night
then diminish on Wednesday as the low lifts out to the northeast. A
surge of much cooler air will follow Wednesday night into Thursday
as high pressure approaches and pushes Canadian air south across our
region. High pressure will crest over the area Thursday night
bringing a clear, calm and cold night possibly with some Frost in
the colder northern valleys. A mostly sunny and seasonably cool day
should follow for Friday with high pressure remaining over the
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
NEAR TERM: Mainly VFR conditions tonight in light and variable
winds. Early morning IFR/LIFR in low terrain terminals due to
areas of fog. For Saturday, ample VFR conditions with light and
Monday night...VFR Lowering to MVFR or IFR Downeast and MVFR over
the north. Light S wind.
Tuesday IFR downeast, MVFR possibly lowering to IFR north. Light SE
Tuesday night...IFR, Possible S LLWS. S wind.
Wednesday. IFR improving to VFR Downeast and MVFR north. Light S
wind becoming NW and gusty late.
NEAR TERM: Winds will remain below SCA, however, Hurricane Earl
will cause seas to increase throughout tonight into Saturday.
Long period swell waves of 13-15 sec will build in generating
wave heights of 5-7 ft in the outer waters and up to 5 ft for
intracoastal waters. Thus a Small Craft Advisory has been issued
beginning tonight through Saturday evening.
Wind and seas are expected to be below SCA Tue night through
mid- week. However, a cold frontal passage may result in some
brief wind gusts up to 25 kt on Wed. Humid air over the waters
and showers may lower vsby Tue into Tue night.
ME...High Surf Advisory from 5 AM to 8 PM EDT Saturday for MEZ029-
MARINE...Small Craft Advisory until 11 PM EDT Saturday for ANZ050-051.
Small Craft Advisory from 6 AM to 8 PM EDT Saturday for ANZ052.
Area Forecast Discussion...UPDATED
National Weather Service Morristown TN
1034 PM EDT Fri Sep 9 2022
Issued at 1018 PM EDT Fri Sep 9 2022
Forecast appears to be in good shape. Made only some slight
adjustments to PoPs and winds over the next few hours, and largely
blended towards the previous forecast from late tonight through
the daybreak time frame. Regional radar imagery shows some light
returns moving NW from SC and GA towards our CWA. Have been hard
pressed to find any rainfall reaching the surface on surface obs
this evening, outside of northwest AL, so did go ahead and lower
PoPs through the next several hours to come in line with the more
recent runs of the HRRR. Otherwise, as mentioned, largely blended
back towards the previous forecast after 06z-09z or so. Continue
to agree with the day shift that there`s a possibility that some
advisory level wind gusts could be seen in the mountains later
tonight. Increasing southeast H85 flow through the overnight
hours will provide some gusty winds to the higher terrain, and the
latest HRRR and even NBM guidance show some mountain wave- like
signatures extending away from the mountains and into the TN
valley after midnight. However, lack of more supporting features
(strong inversion above mountaintop level, strong pressure
gradients across the Appalachians, etc) give me enough pause to
forego issuing an advisory at this time. Think the stronger wind
gusts will be more the exception than the rule, although breezy
conditions are expected in the higher terrain.
(This evening through Saturday)
Issued at 256 PM EDT Fri Sep 9 2022
1. Area of showers and perhaps a few rumbles of thunder will lift
north across the area tonight into Saturday.
2. Gusty winds in some of the higher elevations and foothills of the
E TN mountains tonight into early Saturday.
In the upper levels, a closed low over the lower Mississippi Valley
will slowly drift northwest and weaken. Lower levels will feature
southeast flow that will strengthen tonight and then weaken a bit
and turn more southerly. A band of isentropic lift will surge north
across the area later tonight into Saturday and will be the primary
focus for rain across our area. Convective energy looks very
limited at best, so will include no more than a slight chance of
thunder in the forecast. There will be plenty of available moisture
with PW values approaching 2 inches across much of the area.
However, the band should move quickly enough to keep flooding risk
low most areas. In addition, the low level flow will be downsloping
into the northern/central valley areas which will also help to keep
precip amounts lower in those areas. However, some heavier showers
may linger long enough to produce isolated localized flooding, so
will keep the mention of localized flooding that is already in the
The 850 mb jet will be southeast and approach 30 to 40 kts tonight
into early Saturday. Looking at the vertical wind/temperature
profile and the overall pattern, it does not look very favorable for
mountain wave enhancement. While it looks marginal for a east TN
mountain/foothills wind advisory, still do expect some strong wind
gusts in the normally favored locations tonight into Saturday
morning and this will be mentioned in the HWO as well.
(Saturday night through next Friday)
Issued at 256 PM EDT Fri Sep 9 2022
1. Unsettled, wet weather continues Sunday into Monday ahead of a
2. Cold front moves through Monday with dry and seasonable weather
expected most of next week.
At the start of the extended period, an open wave will be in the
process of phasing with a northern stream wave that will dig into
the midwest. This northern stream wave will eventually become cutoff
on Sunday with an upper low meandering across the Midwest and into
the Ohio Valley into early next week. Southerly flow in the boundary
layer will keep a moist airmass in place Sunday into Monday while
mid level PVA and upper level divergence keeps synoptic scale ascent
across the area for likely or higher PoPs. A front will progress
through the area Monday with much drier air in its wake.
Precipitation chances will be tapering off from west to east on
Monday with the highest chances being along and east of I-81, across
portions of northeast Tennessee and southwest Virginia.
The upper low begins to move off toward the northeast Monday night
into Tuesday. Behind this feature, heights will begin to increase as
ridging sets up across the plains and MS River Valley. This will
keep conditions dry Tuesday through Friday with temperatures near
Issued at 756 PM EDT Fri Sep 9 2022
Expect VFR flight categories to continue until late tonight for
KCHA and probably into the morning hours for KTYS and KTRI.
Current guidance shows band of showers lifting north into the TN
valley between 09z and 11z. Easterly flow across the Appalachians
will likely hinder showers moving north through KTYS and KTRI so
have trended TAFs accordingly. Ceilings are expected to fall to
IFR levels at KCHA but may be slow to lower further north due to
downslope flow counteracting increasing low level moisture.
.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN 84 68 77 70 / 20 80 80 50
Knoxville McGhee Tyson Airport, TN 84 67 78 68 / 20 70 70 50
Oak Ridge, TN 85 66 76 67 / 20 70 80 50
Tri Cities Airport, TN 81 63 76 65 / 10 40 80 60
Area Forecast Discussion
National Weather Service Portland OR
323 PM PDT Fri Sep 9 2022
.SYNOPSIS...A strong east wind event is on tap for today into
early Saturday. This will bring critical fire weather conditions,
above normal temperatures, and smoke and haze in various quantities
for different parts of the area. A southerly flow reversal Sunday
into Monday will lead to a strong onshore push which will replenish
moisture for lower elevations, along with a cooling trend next week.
..DISCUSSION (through Thursday)...Water vapor satellite imagery at 3
PM shows tremendously dry mid levels as northeast flow continues
across Oregon and Washington behind an upper trough which is diving
southeastward towards the Great Basin. Below normal temperatures
continue as the cool air mass associated with this trough has become
entrenched across eastern Oregon and Washington, while west of the
Cascades temperatures are running a solid 10 degrees above normal as
east flow is downsloping across the Cascades.
The North Bend minus Spokane pressure difference has increased to
15.4mb as of 2PM (which is over-performing a bit from what guidance
has suggested), and unsurprisingly wind speeds have spiked in
response. Gusts to 40 mph have been observed in many locations,
including at PDX with the onset of the easterly surface flow this
morning from the Gorge. Overall, HREF is suggesting peak gusts for
most areas will be 10-15mph less than they were during the 2020
Labor Day event, so we`ll continue to message the possibility of
gusts to around 25-35mph across much of the Willamette Valley, 35-
45mph near the Portland/Vancouver Metro, and 45-55mph across the
high Cascades and exposed areas in the Foothills this evening.
Overnight tonight, the event will turn into more of a classic gap
flow event, where areas within and downwind (i.e., west) of the gaps
in the Cascades and Coast Range - most notably the Columbia River
Gorge - will experience their highest winds. The mean of the HREF
ensemble is suggesting gusts to 50+mph through the west end of the
Columbia River Gorge tonight, which seems reasonable given the
forecast maximum pressure difference of roughly 8mb from Astoria to
the Dalles for early Saturday morning.
The CAMs have not been doing a great job of resolving where the best
mixing of strong winds a few thousand feet above the surface will
reach the ground thus far during this event, and so it`s doubtful
they will do well tomorrow either. Still, it`s worth noting they`re
suggesting another burst in the northern lowlands when surface
heating begins tomorrow morning. This seems like a reasonable
possibility given forecast soundings are advertising still a fair
amount of wind even just a thousand feet above the ground at that
time, though the strong winds aloft will be quickly easing as the
gradient weakens with the northeastward shift of the coastal thermal
trough and resultant moderating temperatures east of the Cascades.
As a surface low moves up the coast Saturday and Saturday night, a
southerly flow reversal will overspread the forecast area from the
southwest to bring in cooler conditions and increase low level
moisture, finally assuaging some fire weather concerns for many (but
not all) areas; more details on that follow in the fire weather
The other concern is wildfire smoke. DEQ`s website suggests air
quality has deteriorated into the moderate category for many
locations, including (1) the Portland Metro where smoke has entered
the area from wildfires to our north and east, and (2) the Eugene
and Corvallis areas where smoke has arrived from primarily the Cedar
Creek Fire near Oakridge. The particulates resulting in this reduced
air quality are PM2.5, which are particularly hazardous to human
health, so staying inside and keeping windows closed if possible is
recommended. It is uncertain what will happen with air quality
across the area tonight into tomorrow, but the HRRR smoke model
suggests additional smoke will filter into the region from the east
due to the strong winds.
Saturday will also be a hot day, and some locations will have the
potential to experience record high temperatures as readings climb
into the mid to upper 90s inland and low 80s to locally 90 along the
coast. NBM continues to hint at this potential heat for coastal
communities as it advertises a 60% chance for highs above 85 degrees
at Astoria. The one exception to the heat inland will be in parts of
Lane County where the smoke concentration is the greatest and high
temperatures could be cut several degrees short by the smoke`s
limiting effect on incoming short wave radiation.
The CAMs are hinting that some convection could fire along the
leading edge of the cold front from the offshore low Saturday
evening, though no members of either the EPS or GEFS ensembles are
putting QPF anywhere in the area and soundings suggest the moisture
will be above 600mb (except along the coast where there will be some
marine moisture). Given the conflicting data, a 20% chance for
showers was added to much of the area tomorrow evening/night,
meaning there will be a four times greater probability that rain
will not fall than that it will. Anything that falls will likely
only be a few sprinkles, as is often the case with virga.
Sunday, onshore flow keeps the area much cooler compared with
Saturday, and the southwest to west flow should drive much of the
smoke out except in the immediate vicinity of fires. (Unfortunately,
this could result in a wave of low level smoke surging up the
Willamette Valley into southern Washington Saturday night into early
Sunday morning. But even so, the front is likely to loft whatever
low level smoke is present so that it is no longer concentrated near
The upper low finally passes above the area Monday, deepening the
marine layer and likely resulting in drizzle for low elevations both
Monday morning and possibly Tuesday morning as well. The EPS
ensemble even has several members producing QPF for PDX Monday
morning, indicating the drizzle could reach inland locations too.
Overall, the pattern for early to mid week next week looks much
cooler; according to cluster analysis there isn`t a whole lot of
spread among the ensemble members in the upper level synoptics, and
according to NBM there isn`t much spread in the low level weather
conditions forecast by those members either. NBM gives around a 75-8
5% chance that highs will not surpass 80 Tuesday through Thursday of
next week. -Bumgardner
.FIRE...Significant offshore wind event is underway this
afternoon as a well defined thermal trough resides along the CA and
OR coasts while surface high pressure builds over the Columbia River
Basin, promoting moderate to strong east winds over much of
northwest OR and southwest WA. Relative humidity values are
generally in the teens across the area with a few obs showing single
digits in Willamette National Forest. Red Flag Warnings remain
largely on track with respect to timing and forecast details. Expect
winds to peak tonight into early Saturday over the higher terrain
and through the Gorge, with some gusts to 50 mph over exposed
terrain in the Cascades and 40-45 mph gusts in the Gorge and over
favored terrain in the Coast Range. For Willamette Valley, have
tweaked the wind forecast upward in the northern valley this evening
based on a few gusts to around 40 mph coming out of the Gorge into
PDX this afternoon. Otherwise, still generally expecting winds to
max out around 35 mph in the rest of the valley this evening, with a
relative lull overnight and winds then picking back up Saturday
morning. Overnight recoveries will be poor throughout the area,
struggling to reach 30 percent in most locations and especially in
the Cascades. Winds should diminish relatively quickly on Saturday
night as the thermal trough develops into a closed low and pushes
offshore, weakening the gradient. This will yield improving although
still relatively dry conditions for Sunday. /CB
.AVIATION...00Z TAFs: Strong easterly winds continue throughout
the area with gusts as high as 45 kt at the highest terrain, and
around 30 kt through the Willamette Valley. Currently receiving
reports of LLWS but due to the uniformity of the wind speeds, have
omitted from the forecasts. Satellite imagery shows widespread
smoke from the Cedar Creek Fire pushing eastward over the southern
Willamette Valley including KEUG and KSLE. Seeing some reductions
to visibility due to smoke and haze, and there still remains the
possibility of seeing IFR level conditions if smoke settles
to the surface.
Elsewhere, will likely see some smoke aloft or haze due to nearby
fires, but not expected to be nearly as concentrated. Could see
some eddies forming on the leeward side of the mountains due to
downsloping and warming, although confidence is low. Easterly
winds will strengthen downstream of the Columbia River Gorge at
KTTD and Coast Range gaps such as KTMK and KAST through 06-09z
Saturday before gradually weakening thereafter.
For detailed Pac NW aviation weather information, go online to:
KPDX AND APPROACHES...VFR conditions will persist through the next
24 hours. Will see very gusty easterly winds with speeds upwards
of 35 kt at times. Reports of LLWS below 2000 ft at +/- 10 kt, but
due to a lack of directional shear, have not included in the TAF.
Winds will ease slightly after 10Z Saturday, but not expected to
reduce significantly until later Saturday morning.
.MARINE...A closed area of low pressure continues to push
northward along the coastline which, when combined with high
pressure inland, is creating very strong offshore flow. Expecting
gusty winds around 15 to 20 kt with gusts up to 25 kt throughout
all of the waters, easing from the inner waters westward
starting early this evening. Winds have been slow to increase
today, but have been sitting right along the Small Craft Advisory
wind threshold. However, seas remain elevated with hazardous,
choppy seas. Generally seeing seas around 7 to 9 ft at 9 to 10
seconds throughout the waters. These conditions will persist
through the evening, when they will begin to ease to closer to 5
to 7 ft. Will continue the Small Craft Advisory due to a
combination of winds and hazardous seas.
After this east wind event, will see a wind reversal as onshore
flow returns on Sunday. A southwesterly flow will usher in
monsoonal moisture from the decaying tropical storm off of the
California Coast. Could see slightly elevated winds at that time,
but do think they will be marginal. High pressure builds once
again bringing a typical summertime pattern to the region.
For information about upcoming marine zone changes, go online to:
OR...Red Flag Warning until 8 PM PDT Saturday for Central Oregon
Coast-North Oregon Coast.
Red Flag Warning until 11 PM PDT Saturday for Central Oregon
Cascade Foothills-East Slopes of the Central Oregon Coast
Range-Mt. Hood National Forest West of Cascade Crest-North
Oregon Cascade Foothills-North Oregon Coast Range-
Willamette National Forest-Willamette Valley.
WA...Red Flag Warning until 8 PM PDT Saturday for South Washington
Coast and West Willapa Hills.
Red Flag Warning until 11 PM PDT Saturday for Clark County
Lowlands-East Willapa Hills-Eastern Gifford Pinchot
National Forest Mt Adams Ranger District-Extreme South
Washington Cascades and Foothills.
PZ...Small Craft Advisory from 3 AM to 8 AM PDT Saturday for Columbia
Small Craft Advisory until 9 AM PDT Saturday for Coastal waters
from Cape Shoalwater WA to Cascade Head OR out 10 nm-Waters
from Cascade Head to Florence OR from 10 to 60 nm.
Small Craft Advisory until 3 AM PDT Saturday for Coastal waters
from Cascade Head to Florence OR out 10 nm.
Small Craft Advisory until 3 PM PDT Saturday for Waters from
Cape Shoalwater WA to Cascade Head OR from 10 to 60 nm.
Interact with us via social media:
Area Forecast Discussion
National Weather Service Reno NV
301 PM PDT Fri Sep 9 2022
Warm daytime temperatures will be present through the weekend, but
cooler days are in store for next week. Shower and thunderstorm
activity will be present for areas in the Sierra Nevada as a
tropical system migrates northward. Chances for showers and storms
remain through early week before the moisture exits to the east
later in the week.
Smoke from surrounding wildfires, especially from the Mosquito Fire
actively burning on the western Sierra slopes, has quickly become a
major concern for northern CA and western NV communities. Smoke will
continue to impact the region for the foreseeable future with
degraded air quality and significant visibility reductions. Recent
HRRR smoke forecast guidance indicates major smoke impacts for the
Martis Valley, Carson Valley, and Tahoe Basin this afternoon. Light
winds overnight will provide little relief, as smoke looks to linger
in these areas into tomorrow morning. A wave of near-surface smoke
looks to push east of the Sierra crest tomorrow afternoon, with
potential for widespread air quality impacts even into the Greater
Reno-Sparks area. If you have outdoor plans this weekend, consider
postponing or cancelling them to days with better air quality as
unhealthy to very unhealthy AQI is likely. For latest air quality in
your location, please visit fire.airnow.gov.
Another round of isolated thunderstorms are possible this afternoon,
mainly for the Eastern Sierra. Biggest concerns for any storms that
develop include dry lightning strikes outside of precip cores and
gusty outflow winds up to 50 mph. Thunderstorm chances increase on
Saturday for most areas south of US-50 as Tropical Storm Kay tracks
into southern CA and pushes moisture northward along the Sierra.
Storms look to develop early tomorrow afternoon, taking a northwest
track through the evening. These storms will likely be wetter in
nature, with localized areas of heavy rain possible. Rainfall amounts
will be generally on the lighter side, up to 0.01", however the
rainfall rates in terrain driven showers could produce wetting rains
of up to 0.25". The areas of main concern are for Mono, Mineral and
even as far north as Alpine County. This calls to attention burn
scars in elevated terrain, since showers in those areas will be the
most efficient rain makers.
A gradual cooling trend continues today, with highs finally below
100 degrees! However, highs through tomorrow will remain above-
average for this time of year. -Whitlam
Sunday into Next Week...
One thing that is certain in the extended forecast, temperatures
will be moderating towards seasonable averages. Sunday kicks off a
series of lowering daytime highs, with western Nevada valleys
starting to see upper 80s to low 90s. Sierra locations will be
refreshed to see 70s and even some 60s! Throughout the week this
trend continues, and by midweek lower valleys will hover in the low
80s. A low moving into the Pacific Northwest has already begun to
shift our airmass, allowing for the influx of cooler temperatures.
So if you`re waiting to be rewarded for your perseverance through
the recent heatwave, your patience won`t have to be prolonged.
Winds will be light through early afternoon, before the typical
afternoon breezes gust to around 25 mph. Monday will be a similar
situation, although the wind field will be influenced from the
south by flow associated with a tropical system. This southerly
flow will become more westerly as the system lifts into the Great
Basin into the latter part of the week. As the system begins an
eastward trajectory by midweek, winds look to become stronger
during our late day breezy period. One other consideration will be
gusty outflows associated with any showers and storms that form
in the eastern Sierra.
Now for the lower confidence items in the forecast...
Smoke from the Mosquito Fire will continue to dominate area skies,
with fluctuating air quality values. This afternoon, the Tahoe Basin
and Carson Valleys are being impacted by poor air quality. The smoke
projections are dependent on the behavior of the fire as well as
wind speed and direction. We are good at predicting winds, but we
cannot predict how a fire will behave. The moral of the story is the
forecasts for smoke plumes will vary daily. For now, we have seen
extreme fire behavior that has created the dense smoke overhead, and
we anticipate the trend to continue for the foreseeable future.
The next item of concern is the tropical system streaming
northwestward along the southern Pacific coast. Recent ensemble
guidance suggests a weakening system as we go forward in time, which
lessens our chances of getting significant rainfall this far north.
Tropical Storm Kay is projected to move further out to sea, and into
cooler waters, which will further the weakening process. Areas along
the Sierra Nevada mountains will see the most impacts from this
system. Higher terrain will help to squeeze out the moisture as the
topographical lift provides additional forcing. For Sunday into
Monday, chances range from 45-65% for Mono County, but even the
Tahoe Basin could see chances around 40%. Lower elevations may
only see some cloud cover, although with the smoke coverage, it
could be hard to distinguish cloud layers from the smoke. The
shower chances dwindle to 30-40% into midweek, as the system gets
moved eastward over the Great Basin after being swept into the
main flow. We sure could use some of this tropical moisture to
surge further northward and help us out with the Mosquito Fire,
but it doesn`t seem likely at this time. -HRICH
Smoke and haze will continue to impact most regional terminals
through the weekend. MVFR and occasional IFR conditions are possible
for KTVL/KCXP/KMEV after 00 UTC as high concentrations of near-
surface smoke from the Mosquito Fire pushes east of the Sierra
crest. Additional waves of dense smoke are expected each afternoon
and evening this weekend. Otherwise, haze will impact slantwise
visibility for all terminals.
Isolated thunderstorms are possible this afternoon for Mono and
southern Mineral counties, which may impact KMMH. Storms look to
produce little rain today, but they are capable of producing gusty,
erratic outflow winds between 30-40 kts. Thunderstorm chances expand
northward to the US-50 corridor on Saturday, with potential to
impact KMEV/KMMH. These storms look to produce heavier rains, which
may lead to mountain obscurations and reduced vis/cigs. -Whitlam
As we close the book on this unparalleled early September heat wave,
the number of records set at Reno are plentiful:
* New Daily Record Highs: 7 days in September with new records set,
plus 2 more days on August 30-31 with tied record highs. The
record of 106 on 9/6 blew past the previous record on that date by
an impressive 10 degrees!
* Warmest September Temperature: 106 degrees on 9/6. This surpassed
the highest temperature ever reported in September (and even
August), and was equal to the 4th hottest day in Reno`s climate
* Latest Calendar Day with 100+ degrees: Set on 9/8/2022, three
days later than the previous record from 2020.
* Total number of 100+ degree days in September: 8 days. Prior to
2022, only 8 100+ degree days occurred in September through the
ENTIRE climate history of Reno, going back to 1888.
* New Daily Record High Minimums: A total of 5 record high minimum
temperatures were set and 2 were tied between 8/30 and 9/8.
* Warmest minimum temperature for any September day: 69 degrees on
9/7, surpassing the previous record of 67 degrees.
* Consecutive 100+ degree days: 9 days, from 8/31 through 9/8. This
is the third longest such streak, just short of two 10-day streaks
which occurred in July 2005 and July 2021.
* Total number of 100+ days in a calendar year: 22 days, equaling
the record total set just last year.