Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 09/15/20
Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
733 PM CDT Mon Sep 14 2020
.UPDATE...
Issued at 732 PM CDT Mon Sep 14 2020
Cancelled the Red Flag Warning a little early this evening as
conditions are improving with rising RH and diminishing gusts. The
remainder of the forecast is still on track and no further changes
are planned.
&&
.SHORT TERM...(This Evening through Tuesday Night)
Issued at 207 PM CDT Mon Sep 14 2020
Somewhat persistent mid-level pattern is expected to continue over
the CONUS for the short range. The pattern being close to a positive
PNA setup. Rain chances look nil through the period given pretty
much capped environment over the region. The main issue is probably
smoke and perhaps fire danger. Warm front will continue to lift
north of the region tonight, with somewhat higher dewpoints expected
to advect north over the area. This will serve to keep overnight
lows rather mild, and should also lead to a bit higher RHs Tuesday
afternoon. Winds should also be a bit less gusty Tuesday afternoon.
For now not planning on any fire headlines. Meanwhile, HRRR smoke
model continues to indicate plenty of smoke aloft across the area
through Tuesday, and perhaps even some near sfc smoke over the
western part of the state on Tuesday. Will keep hazy conditions in
the grids, and will evaluate sfc smoke in later forecasts. A front
slides through Tuesday night with a return to lower dewpoints, and
cooler temperatures. Overall, though, temperatures will remain above
normal through most of the forecast period especially for Tuesday as
winds turn a bit southwest in the afternoon ahead of the approaching
cold front.
.LONG TERM...(Wednesday through Monday)
Issued at 207 PM CDT Mon Sep 14 2020
Will start out the long term period with an upper flow pattern that
consists of a cut-off upper low off the Pacific Northwest, a ridge
over the northern Rockies, and an eastern CONUS trough with a
northwest flow regime overhead. That means the forecast will be
initially dry, however a weak northwest flow wave, combined with mid-
level warm advection could support enough lift for some weak
convection early Thursday. Easterly low level flow and cloud cover
will probably limit warming during the day Thursday and Friday
however. A warm up returns for the weekend, as the aforementioned
Pacific Northwest upper wave moves across the Northern Rockies, and
brings in additional thunderstorm chances.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday Evening)
Issued at 623 PM CDT Mon Sep 14 2020
Terminals KABR,KATY,KPIR,KMBG
VFR conditions are expected through the next 24 hours. However,
haze from smoke will affect the region through the period, as
well, and may start to affect vsby on Tuesday across central SD.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...None.
MN...None.
&&
$$
UPDATE...Wise
SHORT TERM...TDK
LONG TERM...Connelly
AVIATION...Wise
Area Forecast Discussion
National Weather Service Binghamton NY
947 PM EDT Mon Sep 14 2020
.SYNOPSIS...
High pressure building in clears the sky of clouds though a thin
layer of smoke will be present aloft. Sunny skies with light
winds are expected for Wednesday before a weakening cold front
approaches Thursday bringing more clouds and isolated showers.
&&
.NEAR TERM /THROUGH TUESDAY NIGHT/...
One uncertainty tonight with the ongoing forecast is if the
high level smoke coming into the region will have any effect on
our low temperatures tonight. For now, temperatures are falling
off fairly quickly and in line with our forecast thinking below.
Ny mesonet data is showing portions of Chenango, Cortland and
Madison counties already seeing temperatures falling into the
low 40`s. Given these trends, low temperatures were decreased
slightly increasing the potential for patchy frost. A SPS was
issued for these counties given coverage does not look
widespread enough for an advisory. Previous discussion below.
Winds at the surface drop off as high pressure builds in along
with very dry air aloft depicted by water vapor imagery, tonight
will have efficient radiational cooling. Areas across northern
Oneida county along with some of the higher valleys in the
Catskills may have temperatures dip into the low 30s, enough for
some patchy fog to develop. With dry ground, the temperatures
right near the surface will cool faster so it is easier to get
some frost development even with lows that may be several
degrees above freezing.
Tomorrow, high pressure is right overhead with clear skies once
again. Any valley fog quickly burns off and temperatures recover
quick. The latest HRRR smoke run still has a thin layer of
smoke well above the surface so skies will look a bit hazy
tomorrow. WAA at 850 mb through the day will help keep overnight
lows warmer tomorrow night. Dry air in place and less efficient
radiational cooling is able to keep fog forming late Tuesday
night into Wednesday
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
220 pm update...
Still some uncertainty in the short term with respect to the
plume of moisture streaming north from the remnants of Sally and
also from the southern Atlantic coast. At this time it appears
any significant rainfall will remain to the south and se of the
forecast area, but this will require some monitoring through the
next couple days.
Quiet weather is expected on Wednesday with a surface high off
the Northeast coast and a broad/flat upper ridge overhead. Skies
should be mostly sunny with daytime heating and warm air
advection contributing to afternoon highs in the upper 70s and
lower 80s. Winds may be a bit breezy Wed afternoon as well with
sustained south winds around 15-20 mph and gusts up to 25-30
mph. The upper level pattern becomes slightly more amplified Wed
night into Thursday as a broad upper trough drops into the
upper Midwest and wrn Great Lakes. At the same time remnants of
Sally will be lifting north and ne through the Southeast US. At
this point it appears the incoming wave to the north will move
in before the tropical air mass is able to lift far north enough
to impact ne PA or central NY. Most of the model guidance
continues to hint at only a glancing blow of up to a quarter of
an inch of rain, at most, over parts of ne PA and the far srn
Catskills later on Thursday. So, have decided to stay with
persistence and continue with the chance PoPs coming in Thur
afternoon with light precip amounts.
Temperatures Wed night will be mild as increased cloud cover
keeps lows in the 50s. Highs on Thursday will be very
seasonal...topping out in the 70s.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
220 pm update...
The incoming wave from the west/nw may have enough large scale
forcing and enough moisture to work with to create some
scattered rain showers Thursday night, but by Friday morning the
deep dry air should be overtaking most of the region and allow
most of the rain to come to an end from west to east.
A large dome of high pressure with much cooler temperatures will
settle in late Friday through most of the weekend with very quiet
weather conditions, highs in the upper 50s and lower to mid
60s...and overnight lows in the 30s and 40s. Could have
favorable conditions for frost.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
Dense river valley fog will form at KELM overnight, beginning
around 08z and ending around 14z. Expect visibilities of 1/4SM
or less and ceilings around 100 feet in fog.
Otherwise, mostly clear skies and light winds will prevail for
the next 24 hours.
Outlook...
Tuesday evening through Wednesday night...VFR, except valley
fog KELM late nights-early mornings.
Thursday through Thursday night...Occasional restrictions
possible with isolated showers.
Friday into Saturday...Mainly VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...None.
NY...Frost Advisory from 1 AM to 9 AM EDT Tuesday for NYZ009-046-
057.
&&
$$
SYNOPSIS...AJG
NEAR TERM...AJG/MWG
SHORT TERM...BJT
LONG TERM...BJT
AVIATION...DJP
Area Forecast Discussion
National Weather Service Bismarck ND
1009 PM CDT Mon Sep 14 2020
.UPDATE...
Issued at 1007 PM CDT Mon Sep 14 2020
The forecast for tonight remains on track. No changes with this
product issuance.
UPDATE
Issued at 634 PM CDT Mon Sep 14 2020
Opted to add in areas of smoke west for tonight with a few
visibility restrictions starting to show up the last couple of
hours at Beach, Tioga, Estevan, Watford City, and over portions of
eastern Montana. HRRR near-sfc smoke model has this depicted well,
expanding slowly to the east overnight and through the day
Tuesday. For now kept smoke and/or haze through Tue afternoon,
leaving out Tue night for now but will need it eventually.
Otherwise the forecast for tonight remains on track.
&&
.SHORT TERM...(This evening through Tuesday)
Issued at 218 PM CDT Mon Sep 14 2020
Current surface analysis places low over southern Saskatchewan
into north central Montana with high over the Great Lakes into
the Midwest. Upper level analysis places broad ridge over the
Rockies into the plains. Some high clouds lifting over the ridge
continue to pass through our area. The main feature, though,
continues to be the smoke aloft. The smoke has had some influence
on temperatures today, as we have remained cooler than expected.
For tonight, a cool front starts to drop through the area tonight.
Main concern with this is whether this will have an influence on
mixing some smoke down to the surface, particularly over western
locations. Will continue to advertise widespread haze for now,
but will have to keep an eye on observations and reports to see if
this mixing down does develop.
On Tuesday, cool front will continue to drop through the area in
the morning, but the colder air will this system will lag behind
a bit, so a mild day is expected. Have dropped temperatures down a
bit, though, due to the influence of the wildfire smoke. Ridge
breaks down over our area, though will strengthen over the western
United States.
.LONG TERM...(Wednesday through Monday)
Issued at 218 PM CDT Mon Sep 14 2020
Cool high pressure settles in for Wednesday, bringing a notably
cooler day. Low precipitation chances enter the forecast for
Thursday as modest cyclonic flow sets up over the region. Models
push a compact low over the Pacific Northwest on Friday, which
will zip towards our area for the weekend bringing precipiation
chances.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 634 PM CDT Mon Sep 14 2020
VFR conditions expected through the forecast period. Reduced
visibility in patchy/areas of smoke expected across western ND
tonight at times. This will likely continue Tuesday, expanding to
the east.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...NH
SHORT TERM...JJS
LONG TERM...JJS
AVIATION...NH
Area Forecast Discussion
National Weather Service Burlington VT
1014 PM EDT Mon Sep 14 2020
.SYNOPSIS...
High pressure will build into our region tonight with mainly clear
skies and light winds anticipated, areas of frost are expected in
the colder valleys, away from Lake Champlain. Tuesday will feature
filtered sunshine as high level smoke from western fires impacts our
area again with temperatures in the upper 50s to mid 60s. Breezy and
milder conditions return on Wednesday, before a cold front with
scattered showers arrives for Thursday.
&&
.NEAR TERM /THROUGH TUESDAY NIGHT/...
As of 1014 PM EDT Monday...Minor changes needed to late evening
temperatures, winds, and sky cover, but we remain on track to
see the coldest overnight conditions of the season in northern
New York and much of Vermont where frost and freeze conditions
will develop overnight. Aside from a few passing clouds in
northern portions of the forecast area, skies have remained
clear, promoting good radiational cooling and pre-dawn fog in
favored river valleys. It is already 33 degrees at the
Adirondack Regional Airport, our region`s typical cold spot. In
contrast, persistent northwesterly winds in the Champlain Valley
are keeping temperatures relatively mild in the low 50s. Made
some slight increases to wind speeds in this area through the
next few hours, but as the pressure gradient weakens, winds
should gradually fall off and so will temperatures. However,
lows there are still expected to remain too mild for frost.
Finally, lowered cloud cover with no widespread clouds through
the early morning hours, but we still may see some high clouds
from upstream over Ontario arrive towards daybreak.
Previous Discussion...
Sfc analysis places center of 1031mb high pres over northern MI
with cyclonic northwest upslope flow prevailing acrs our cwa
this aftn, along with some diurnally driven fair wx cumulus,
under filtered sunshine from high level smoke from western
fires. Tonight the fcst challenge will be temps and areal
coverage of frost/freeze conditions. Little change made with
regards to our thinking with temps mid/upper 20s slk/nek where
freeze warning continues, while SLV, central/northern VT and
valleys along the western slopes experience temps in the lower
to mid 30s with frost advisory. Meanwhile, upper 30s to mid 40s
occur in CPV. Some patchy frost possible away from the Lake, in
places like Essex, Milton, Sheldon, and Whiting, but coverage
will be patchy at best with temps in the mid 30s. Some questions
to think about, does high level smoke impact radiational
cooling tonight, nam 3km shows lingering moisture around 850mb,
does trrn clouds persist, and how quickly do winds decouple,
will factor into temps overnight. Dewpoints have been slow to
drop this aftn, so thinking a few locations will drop below
cross over value with patchy fog possible, especially climo
favored areas that received rainfall on Sunday.
Tuesday, expecting filtered sunshine again with impacts from smoke
likely, given HRRR output and upstream satl trends. Temps under
developing llvl waa wl warm into the upper 50s to mid 60s by mid
aftn. Winds generally light from the north at 4 to 8 mph, before
switching to the south toward evening. 925mb to 850mb jet increases
overnight into the 30 to 40 knot range by 12z Weds, supporting
warming llvl thermal and a challenging temp fcst overnight. Thinking
temps drop quickly early evening with lows mid 30s to upper 40s,
before warming aft midnight, especially wider valleys of the
SLV/CPV, where southerly winds increase.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
As of 258 PM EDT Monday...Another dry but windy day is expected
Wednesday as strong surface high pressure shifts offshore while a
cold front approaches from the west. Pressure gradient tightens up
early Wednesday morning with southerly gusts in the 20-30 mph range
likely on land through the day, while on Lake Champlain gusts could
exceed 35 mph producing wave heights in the 3-6 foot range. Probably
be dealing with a decent amount of smoke in the air as well per
latest HRRR smoke model until a cold front swings through on
Thursday. No big changes to the timing of the front as guidance
continues to come into agreement there. It appears chances for
precip will increase after midnight and expect scattered showers to
slowly progress northwest to southeast through the day, exiting east
of the region by Thursday night. Overall QPF will be light in
intensity, and generally less than a quarter inch.
Despite the smoke, highs Wednesday should reach into the mid 70s
across the region, with a cooler day in the 60s on Thursday.
Wednesday night lows will range through the 50s.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
As of 258 PM EDT Monday...Behind the front, another very quiet period
of weather is expected as an expansive area of high pressure will
build in for Friday through the weekend with an abundance of
sunshine during the day and clear cool nights. Highs will be cool in
the 50s for most locations through Sunday, then warm into the 60s on
Monday. Areas of frost will be possible each night across much of
the region, especially in the Adirondacks and central/northeast
Vermont where temps drop into the 30s.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
Through 00Z Wednesday...VFR conditions will continue at
terminals, except for a period of dense fog and low clouds causing
VLIFR visibilities and ceilings at MPV and SLK. Most likely time
frame for these conditions is between 08Z and 13Z. Otherwise,
surface high pressure will limit wind speeds to mainly under 5
knots through 18Z, with slightly higher wind speeds developing
after that time, especially at New York sites where return
southwest flow will commence.
Outlook...
Tuesday Night: VFR. NO SIG WX.
Wednesday: VFR. NO SIG WX.
Wednesday Night: Mainly VFR, with local MVFR possible. NO SIG WX.
Thursday: Mainly VFR, with local MVFR possible. Chance SHRA.
Thursday Night: VFR. Chance SHRA.
Friday: VFR. Slight chance SHRA.
Friday Night: VFR. NO SIG WX.
Saturday: VFR. NO SIG WX.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...Freeze Warning until 9 AM EDT Tuesday for VTZ004.
Frost Advisory until 9 AM EDT Tuesday for VTZ003-006>008-010-
016>018.
NY...Freeze Warning until 9 AM EDT Tuesday for NYZ030-034.
Frost Advisory until 9 AM EDT Tuesday for NYZ026-027-029-031-
087.
&&
$$
SYNOPSIS...Taber
NEAR TERM...Kutikoff/Taber
SHORT TERM...Lahiff
LONG TERM...Lahiff
AVIATION...Kutikoff
Area Forecast Discussion
National Weather Service Grand Forks ND
906 PM CDT Mon Sep 14 2020
.UPDATE...
Issued at 906 PM CDT Mon Sep 14 2020
Still have a parade of clouds moving across the FA. There are a
few locations reporting a 5000 foot ceiling, one across the
western Devils Lake region and another around the Lake of the
Woods.
UPDATE Issued at 633 PM CDT Mon Sep 14 2020
A quiet night is anticipated. A fair amount of smoke and cirrus
will continue to drift across the FA.
&&
.SHORT TERM...(This evening through Tuesday night)
Issued at 310 PM CDT Mon Sep 14 2020
The primary impacts or concerns will be temps and impact of thick
cirrus/smoke on the day time highs and then possible air quality
issues. Over the next 18 to 24 hours will see a weak surface low
slide across the forecast area. Ahead of the low will continue to
see warm advection and southerly winds. Strong capping will limit
precip from developing even as 850mb winds increase this evening
as low level jet of up to 40 kts develops. Lows tonight will be in
the 50s and low 60s. Trailing trough or wind shift will slide
south across the area tomorrow morning with winds becoming
northerly during the daytime from NW to SE across the area. Went a
bit lower with temps tomorrow as smoke has limited insolation and
heating at the SFC today. Will see a good gradient with highs in
the low 80s in the south ahead of the wind shift and upper 60s in
the Devils Lake basin behind the trough. Will need to monitor the
surface observations behind the wind shift as HRRR is suggesting
that some of the upper level smoke maybe transported downward to
the surface tomorrow. Air quality and vsby may be impacted. Model
trend continue to paint the western portions of the area with the
best chance of occurrence.
.LONG TERM...(Wednesday through Monday)
Issued at 310 PM CDT Mon Sep 14 2020
Main concerns this period continue to be a drop in temperatures,
potential frost/freeze conditions, and possible rainfall on the
weekend. The jet stream dipping into the Red River Valley will bring
below normal temperatures for the remainder of the work week, thanks
to cold air advection. Confidence is increasing for the potential of
more frosts and/or freezes in our future because of lows in the 30s
and light winds on both Thursday and Friday mornings so that is
something we will have to watch closely. Considering many locations
that could be seeing freezing conditions with this have already had
their first freeze of the season, impacts will be minimal other than
having to scrape your windshield. Highs will stay in the 50s and 60s
to end the week.
Our next concern comes with an upper level trough riding behind the
ridge. It is not appearing to be significant as of now, though
confidence is on the low side about the rainfall aspect due to
ensemble spread. The worst case scenario as of now appears to be up
to a 1/4 of an inch of rainfall heading into next week. Again, the
signals are there saying that rain will come, but we are lacking the
confidence to say exactly how much as of now. It is appearing to be
of minimal impact to any weekend plans right now.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 633 PM CDT Mon Sep 14 2020
A low level jet is expected tonight, mainly impacting KFAR and
KBJI with low level wind shear. Otherwise, surface winds will drop
off this evening, then increase again Tuesday mid morning. A
northwest wind switch is also expected on Tuesday. Finally, models
are showing some MVFR clouds developing at KGFK and KTVF around
sunrise Tuesday. Confidence not really high, but mentioned a TEMPO
group at KGFK and KTVF for that.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...None.
MN...None.
$$
UPDATE...Godon
SHORT TERM...JK
LONG TERM...AK
AVIATION...Godon
AREA FORECAST DISCUSSION
National Weather Service Hastings NE
623 PM CDT Mon Sep 14 2020
.DISCUSSION...(This evening through Monday)
Issued at 355 PM CDT Mon Sep 14 2020
Mainly dry and warm is the theme, though there are a few
relatively minor forecast "issues" to keep an eye on.
Upper air analysis indicates strong upper ridging continuing to
dominate the weather over much of the central CONUS. A weak upper
trough can be seen over the Desert SW, but the main upper
westerlies remains well N, closer to US/Canadian border. At the
sfc, ridge axis continues to slowly shift E thru the Midwest as
lee troughing deepens over the High Plains. This is resulting in
return S/SE flow locally, but the air remains dry w/ Tds in the
upper 40s and 50s.
A belt of smoke can be seen on satellite imagery essentially
stationary over S Neb. This high level smoke that will likely not
be going anywhere any time soon given very weak flow above H6.
Thus, filtered sun conditions will continue for at least the next
24-36 hrs, and maybe even more noticeable tmrw aftn-eve per latest
HRRR smoke progs. Would expect to see additional waves of smoke
thru the week, even once upper flow incr, as there is simply just
a lot of smoke and a lot of fires over W/NW CONUS where upper flow
will be coming from.
Other than the smoke, skies will be clear overnight. Can`t
completely rule out some patchy valley fog over E/SE portions of
CWA as forecast lows are a few deg below crossover temps. Haven`t
included in forecast attm as Srly winds likely won`t completely
decouple, but will pass along to eve shift to watch areas from
Beloit to HJH to JYR.
Another caveat to keep an eye on is potential for near critical
fire weather over the far W tmrw aftn. Winds will be a bit brzy
out of the S/SSW and high temps will be at or 1-2 deg above today.
Moisture doesn`t change much as offshore flow continues over W
Gulf of Mexico. Current RH progs are just above near-critical
criteria around 26-28 percent, but situations like this usually
trend drier with time. Kept mention out of the HWO, for now, but
may need it for far W few counties. There`s also a non-zero chc
for at least near-critical values later this week and into the
weekend. Continued sunny skies, breezy winds, and very little chc
for pcpn will allow drought conditions to steadily worsen, which
will only add to fire wx concerns and allow for RHs to run on the
low side, esp. since we`re past crop evapotranspiration season.
A weak cold front will slide thru the area on Wed, but main push
of colder air remains N, so really it`ll just be a wind shift and
slightly less dry air. The ridge axis looks to remain progressive
such that return flow sets up already by Thu aftn. Weaker mixing
over E CWA may keep highs closer to 80F, but elsewhere should see
mid-upper 80s. Model diffs for Fri appear to have resolved
themselves as EC is no longer indicating clds and 60s. In fact,
latest EC ensemble has jumped from mid-upper 60s for highs Fri to
80s on latest run.
Pcpn chcs remain very limited thru the forecast. Blend tried to
give slgt chc PoPs Thu night, but kept out for now as just don`t
want to over promise rain at this point. It was only slgt chc over
far N anyway. The next chc arrives at some point next weekend
with a cold front, but the front doesn`t look terribly strong.
&&
.AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Wednesday)
Issued at 616 PM CDT Mon Sep 14 2020
VFR conditions are expected through the period with a few high
level clouds and steady southerly winds near 10KTS expected
through the overnight hours. Expect winds to increase again during
the late morning hours Tuesday as a fairly tight pressure gradient
remains in place across the region and mixing to near 850 MB is
realized.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
DISCUSSION...Thies
AVIATION...Rossi
Area Forecast Discussion
National Weather Service Lincoln IL
802 PM CDT Mon Sep 14 2020
.SYNOPSIS...
Issued at 211 PM CDT Mon Sep 14 2020
While few clouds are expected across central Illinois through
Tuesday night, a smoke layer will persist and diminish the amount
of sunshine on Tuesday. Pleasant nighttime sleeping temperatures
are on tap, with lows in the 50 to 55 degree range tonight. Expect
highs on Tuesday to be around 80 degrees across the region.
&&
.UPDATE...
Issued at 759 PM CDT Mon Sep 14 2020
High pressure is centered over the Great Lakes with ridging
extending back across the mid Missouri Valley. On the southern
periphery of this ridge axis, fair conditions are in place across
central Illinois with calm or light E/NE winds. Hazy conditions
continue aloft due to smoke from western wildfires. No
significant changes to the forecast with only minor adjustments
to hourly trends in the near term.
&&
.SHORT TERM...(This evening through Tuesday)
ISSUED AT 211 PM CDT Mon Sep 14 2020
Expansive smoke layer seen on satellite imagery this afternoon
across the northern half of the CONUS. HRRR vertical smoke
forecast shows this continuing through Tuesday, and forecast sky
grids will reflect the smoke, despite minimal cloud cover. The
smoke had earlier suppressed the diurnal temperature rise, but
lower 80s are being observed south of I-70 where the smoke is
thinner. With more of a south/southwest surface flow on Tuesday,
highs around 80 should be more widespread.
.LONG TERM...(Tuesday night through Monday)
ISSUED AT 211 PM CDT Mon Sep 14 2020
Little in the way of rain is expected in the long term. Remnants
of Hurricane Sally to remain well to our south, so any focus will
be with the cold front passing through Wednesday night. Little
moisture available to work with it, thanks to the hurricane. GFS
and European model have been showing a wind of light rain, with
latest trends shifting closer to the Ohio River. Will maintain
some 20/30 type PoP`s mainly south of I-70 Wednesday and Wednesday
night for now.
Still some model variability in the southward extent of the colder
air with the northern stream trough late week. The Canadian model
is the coldest, with 850 mb temperatures around 3C by Friday
evening, though in the middle time-wise. The European model delays
the coldest air until Saturday evening, at which point the GFS is
already showing a significant warming trend. Will favor more of a
mid-point solution for now, which features highs in the mid-upper
60s and and lows dipping into the mid 40s by Saturday morning. All
models show upper level ridging coming in late weekend and a
warming trend.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 605 PM CDT Mon Sep 14 2020
Fair weather is expected across central Illinois under the
influence of high pressure over the Great Lakes. A thick layer of
smoke is expected to persist at or above 150 in otherwise clear
skies. Light east winds will veer to southerly on Tuesday.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Deubelbeiss
SYNOPSIS...Geelhart
SHORT TERM...Geelhart
LONG TERM...Geelhart
AVIATION...Deubelbeiss
Area Forecast Discussion
National Weather Service Northern Indiana
710 PM EDT Mon Sep 14 2020
.SYNOPSIS...
Issued at 1034 AM EDT Mon Sep 14 2020
Dry, fall like conditions prevail through the middle of next
week, with just a low chance of rain on Thursday. Tuesday morning
will be quite chilly with lows in the lower and middle 40s.
Temperatures then moderate to near 80 by Wednesday, followed by
another reinforcing shot of cooler air for the weekend.
&&
.SHORT TERM...(This Evening through Tuesday)
Issued at 228 PM EDT Mon Sep 14 2020
Ridge axis of high pressure centered across Ontario will slowly
drift across the region through Wednesday with the coldest night
coming up tonight as strong radiational cooling, combined with
advection of lower dewpoints from the NE, lead to lows likely under
guidance values (AOA 50) in the middle 40s. Potential flies in the
ointment could be lack of full decoupling of wind field or lack of
full advection of low to mid 40 dewpoints upstream. Will ride with
previous forecast thoughts and keep lows as is.
Sky obscuration issues will be confined to either thin cirrus or
high level smoke particulates that will continue to linger for the
next several days across the region. HRRR smoke loops shows an
increase in these levels as we get into tonight, which should allow
for a nice sunset tonight.
&&
.LONG TERM...(Tuesday Night through Monday)
Issued at 228 PM EDT Mon Sep 14 2020
...Dry conditions to persist well beyond the long term period. Brief
shot of cold air arriving for the weekend...
Unfortunately no hope for any meaningful rain into the long term and
beyond period as best moisture for approaching cold front Weds night
into Thurs remains trapped as ridge axis over our area settles
south, trapping gulf and tropical related moisture. Remnants of
Sally and its needed rain this far north will stay in areas that
generally don`t need it. Spurious pops that have been placed into
grids over past days have been removed.
Only other item to note will be the quick shot of colder air still
in store for Fri into Sat with highs struggling into the 60s and
lows dropping well into the 40s and if ECMWF is correct maybe some
mid and upper 30s (would be just shy of records, but close enough to
make those with outdoor plants and flowers cringe). Will see how it
unfolds through the week. Slow moderation of temps will occur as
upper level heights slowly begin to increase.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday Evening)
Issued at 705 PM EDT Mon Sep 14 2020
No noteworthy changes to the TAFs for this cycle. Diurnally-
driven cumulus at FWA will quickly fade with sunset. Otherwise,
high cirrus/smoky skies from western wildfires through the TAF
period.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...Roller
SHORT TERM...Fisher
LONG TERM...Fisher
AVIATION...Brown
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Area Forecast Discussion...UPDATED
National Weather Service North Platte NE
903 PM CDT Mon Sep 14 2020
.UPDATE...
Issued at 903 PM CDT Mon Sep 14 2020
A forecast update is in place for warmer temperatures across ncntl
Nebraska using the RAP model plus bias correction. A veering low
level jet tonight should funnel warmer air into ncntl Nebraska.
The new forecast is a few degrees warmer than the previous
forecast in that region.
&&
.SHORT TERM...(This evening through Tuesday night)
Issued at 351 PM CDT Mon Sep 14 2020
The warm front that was responsible for some patchy fog this morning
across far northern Nebraska has slowly moved northward into central
South Dakota this afternoon. Thick smoke aloft from wildfires across
the west coast is easily visible on satellite imagery over much of
the northern Plains and upper Midwest. Near critical fire conditions
should continue across portions of the eastern Panhandle and
northern Sandhills into the evening hours before RH recovery begins.
RH values have largely stayed above criteria today, though winds
have been gusting to around 30 MPH across much of the Panhandle and
northern Sandhills. These winds will stay more elevated than the
last couple of nights, and as such should help to keep low temps a
little milder.
A cool front slowly sags into the northeastern portions of the
forecast area during the afternoon hours Tuesday. RH values will
drop into the lower teens to near 10 percent behind this front in
areas west of Highway 61. Luckily winds will be lighter Tuesday
afternoon than they were today, so will forego any fire headlines
with this forecast package. This frontal passage will be dry with
very little in the way of moisture to help drive any precipitation
and should only result in a wind shift to the northwest as it passes
through. This front should clear the CWA by Wednesday morning.
.LONG TERM...(Wednesday through Monday)
Issued at 351 PM CDT Mon Sep 14 2020
Beyond Wednesday, an upper level trough is progged to drop into the
Great Lakes/Ontario and will leave the CWA in broad northwesterly
flow aloft into the weekend. There looks to be some moisture return
Thursday as a mid-level warm front passes through the area.
Unfortunately, this moisture return will not be all that deep, as
recently upgraded Hurricane Sally will help to keep the Gulf closed
off to much in the way of moisture advection northward. This being
said, cannot rule out some showers/isolated thunderstorms across
north central Nebraska in association with this front. QPFs
unfortunately look to be on the lighter side at this time, which
will not help with the ongoing drought/fire concern situation.
Additionally, winds look to shift to more southwesterly Thursday
afternoon across southwest Nebraska and will help to lead to very
deep mixing and could lead to a return to elevated fire weather
concerns.
Upper level ridging looks to briefly build back in during the first
half of the weekend before an upper level low begins to progress
across the northern Plains. A cool front will likely pass through
during the late weekend/early next week and could offer some
precipitation chances, though timing and placement differences in
model solutions leads to very low confidence at this time.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 627 PM CDT Mon Sep 14 2020
VFR conditions should prevail through Tuesday afternoon. Gusty
winds will pick up around KVTN in the early morning hours and
around KLBF in the afternoon. Generally winds will be out of the
south in southwest Nebraska. Winds will shift from the south to
the southwest in northern Nebraska in the early morning. High
altitude haze from western U.S. wildfires is expected to remain
over western Nebraska but will not impact surface visibilities.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE...CDC
SHORT TERM...Brown
LONG TERM...Brown
AVIATION...Meltzer
Area Forecast Discussion
National Weather Service Newport/Morehead City NC
1018 PM EDT Mon Sep 14 2020
.SYNOPSIS...
A cold front will cross the area this evening. Cooler and much
drier high pressure will build in from the northwest through
Thursday. Another cold front could approach the area late in the
week.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
As of 1015 PM Mon...Cold front is offshore with a 1026 mb high
over the Great Lakes ridging into the area from the north.
Stratus continues to hold on over the region with lingering pool
of low level moisture, and latest HRRR suggests these will hold
through much of the night. Can`t rule out a sprinkle or two, but
overall precip threat is over so dropped all PoPs for rest of
the night.
Prev disc...Isolated to scattered showers and thunderstorms
will continue across ENC ahead of a cold front this evening.
Storm will remain below severe limits with meager CAPE and shear
present. The showers should push south of the area by late
evening with the front pushing offshore bringing clearing skies
overnight. CAA will usher in a pleasant airmass with lows
expected in the low to mid 60s inland to upper 60s along the
coast. Long period swells from distant Hurricane Paulette will
impact the beaches bringing large surf and potential ocean
overwash, especially across the OBX. See Tides/Coastal flooding
section below for more information.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
As of 4 PM Monday...High pressure builds into the region from
the north Tuesday bringing dry conditions and comfortable
temperatures with dewpoints in the 60s. Significant drying in
the column with PWs falling below 1" bringing plenty of
sunshine, though will see sct afternoon cumulus with daytime
heating. Highs expected in the upper 70s to lower 80s.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
As of 310 AM Mon...High pressure builds into the area through
Wednesday, bring with it cool, settled weather. The next cold
front will begin to approach the region late week and pull
tropical moisture from the remnants of Tropical Cyclone Sally,
increasing rain chances late week and into the weekend.
Tuesday night through Wednesday...Very cool and comfortable
weather expected through Wed with high pressure building in NW
and dew points limited to the low-to-mid 60s. Highs will hover
around 80 and overnight lows in the 60s inland and low-70s along
the coast. A weak coastal trough looks to nudge its way ashore
on Wednesday, providing an schc for an isolated shower. Guidance
restricts any precip to the southern coast for now and have put
in a low end schc POP to reflect this. Otherwise, will remain
dry both days.
Thursday through Saturday...Developing trough over the Great
Lakes and Northeast will begin to push high pressure offshore.
An associated cold front will make its way towards the area and
draw tropical moisture from the remnants of Sally. Exact timing
and evolution is strongly dependent on the long-term forecast
of Sally and its interaction with the front. At any rate, we can
expect rain chances to begin increasing around Thursday/Friday
with the system moving out at some point Saturday.
Sunday...Cold front will stall offshore as high pressure builds
in from the north. Will remain mostly dry with some rain
chances along the coast depending on where the front lingers.
Tight pressure gradient between the stationary boundary and
building high pressure will make for a breezy NE flow.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
Short Term /through Tuesday/...
As of 740 PM Mon...VFR conditions prevail across the TAF sites
as a cold front sinks south towards the Crystal Coast. A decent
band of lower clouds is developing behind the front but with
drier air filtering in expect these to remain scattered in
nature and expect VFR conditions to continue overnight. High
pressure builds in from the north, reinforcing the drier airmass
and for Tuesday. Cloud heights remain low tomorrow and can`t
rule out a couple hours of MVFR conditions. Main concern is
gusty northeast winds behind the front with a few gusts to 20 kt
possible during the day.
Long Term /Tuesday night through Saturday/...
As of 330 AM Mon...VFR expected to prevail through Wed. Another
cold front will begin approaching Thursday and draw up tropical
moisture from the remnants of Tropical Cyclone Sally,
increasing the chance for POPs and sub- VFR cond through Friday.
&&
.MARINE...
Short Term /through Tuesday/...
As of 400 PM Monday...Adverse marine conditions will persist
through the short term with gusty post frontal winds as well as
large swells impact the waters from Hurricane Paulette as it
lifts north of Bermuda. A cold front will push south across the
waters this evening with high pressure building in from the
north Tuesday bringing N to NE winds around 15-25 kt with gusts
up to 30 kt through Tuesday. Seas have build to 5-9 ft this
afternoon and are expected to peak around 7-10 ft Tuesday
morning, then gradually begin to subside in the afternoon.
This long period swell component will make for especially
dangerous conditions near shoals and crossing inlet bars.
Long Term /Tuesday night through Saturday/...
As of 330 AM Mon...Will continue to see strong swells from
Paulette gradually subsiding through the week. Seas will
gradually drop to 6-8 ft Tuesday night. NE winds will also
diminish gradually to 10-15 kts Tuesday night. Seas will
continue to improve through Wednesday as Paulette continues to
pull away with waves dropping below SCA criteria for the
northern and southern waters initially during the afternoon
followed by the central waters Wed night. Waves will diminish to
3-5 ft Thu and Fri. Winds remain modest around 10-15 kts,
veering E on Wednesday and SE Thursday ahead of an approaching
cold front. Winds shift NNE late Friday and begin to pick up
behind the front Friday night.
&&
.TIDES/COASTAL FLOODING...
As of 430 PM Monday...Long period swell from distant Hurricane
Paulette will continue to increase across the coastal waters
through Tuesday morning. The wave runup from this long period
swell will combine with already elevated water levels associated
with above normal astronomical tides and persistent breezy to
gusty northeast winds to bring the threat for ocean overwash
around the times of high tides beginning this afternoon into
midweek. The easterly swell will be most problematic for
vulnerable east facing beaches including Pea Island to Rodanthe,
Avon, the north end of Buxton, portions of Ocracoke Island, and
Cape Lookout National Seashore north of Cape Lookout.
The next two high tide cycles will be the most problematic for
dune erosion and ocean overwash and have issued a Coastal Flood
Advisory for OBX Dare and Hyde through mid-morning Tuesday. The
higher high tide occurs around 5:30 PM this afternoon, but long
period swells will be peaking around the 6 AM Tuesday high
tide, so want to cover both tide cycles. Swells will be
subsiding through the day Tuesday and there is expected to be
less of a threat during the Tuesday evening high tide cycle.
Additionally, very strong rip currents and powerful breakers
will occur at least into Wednesday.
The high astronomical tide cycle will continue into early next
week and could see minor flooding adjacent to the sounds around
times of high tide from late Wednesday and continuing into the
weekend. In addition, another large swell event may impact the
beaches this weekend.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...Beach Hazards Statement through Tuesday evening for NCZ195-196-
199-203>205.
High Surf Advisory until 8 PM EDT Tuesday for NCZ196-203>205.
Coastal Flood Advisory until 9 AM EDT Tuesday for NCZ203>205.
MARINE...Small Craft Advisory until 6 PM EDT Tuesday for AMZ131-137-230-
231.
Small Craft Advisory until 8 PM EDT Tuesday for AMZ135.
Small Craft Advisory until 10 PM EDT Wednesday for AMZ152-154.
Small Craft Advisory until 7 PM EDT Wednesday for AMZ156-158.
Small Craft Advisory until 4 PM EDT Wednesday for AMZ150.
&&
$$
SYNOPSIS...MHX
NEAR TERM...SK/MS
SHORT TERM...SK
LONG TERM...ML
AVIATION...MS/ML
MARINE...SK/ML
TIDES/COASTAL FLOODING...MHX
Area Forecast Discussion
National Weather Service Marquette MI
759 PM EDT Mon Sep 14 2020
.SHORT TERM...(This evening through Tuesday)
Issued at 329 PM EDT MON SEP 14 2020
Its a relatively calm and uneventful weather day across the region.
The sky has largely been devoid of clouds and temps have warmed into
50s and low 60s across the region. The interesting thing we`ve noted
today has been the sky, where high level hazy has been present for
most of the day, especially toward the south. Both the HRRR
integrated smoke and GOES-16 Smoke Detection product highlights this
region with high confidence smoke particles and looking at the
pattern and tracing these particles backwards with a GFS hysplit
run, these particulates originated in the Pacific Northwest.
The overall pattern over the region is dominated by near zonal flow
with a slight NW flow component across much of the northern CONUS.
Within this flow pattern tonight, a shortwave ejecting out of the
Rockies with developing surface low over the Northern Plains will
progress eastward into the Upper Great Lakes tonight and tomorrow.
Out ahead of the low, a warm front will lift through the region this
evening, with theta-e advection, WAA/isentropic forcings increasing
along the boundary as it lifts through. As a result, rain showers
are expected to develop over Lake Superior. Additionally, with
MUCAPE values near 500j/kg, some elevated thunderstorms will be
possible. Models are in good agreement that the better forcings will
remain over the Lake, but some light rain and drizzle can`t be ruled
out over the region tonight into early tomorrow morning. With the
WAA increasing, expecting overnight lows to bottom out largely in the
50s across the forecast area.
Tomorrow, as the low moves into the region, strong LLJ and deeper
daytime mixing will allow for gusty winds to reach down to the
surface. At the moment, 30 mph gusts across the region are expected.
The strong winds from the south will build waves on Lake Michigan
and Bay of Green Bay, likely resulting in some minor lakeshore
flooding. Will be issuing a lakeshore flood advisory for Delta and
Schoolcraft county for this potential. Daytime highs tomorrow will
climb to ~5-10F above normal. Expecting highs in the west in the
upper 70s to near 80F in downslope locations. In the east, where
Lake Michigan will moderate temps, highs near 70F are expected.
.LONG TERM...(Tuesday night through Monday)
Issued at 412 PM EDT MON SEP 14 2020
Relatively benign longterm forecast ahead as broad troffing and
negative height anomalies remain over the Great Lakes period through
at least the end of the week. Models show a closed off mid-level low
off the Pacific Coast helping keep the troubling ridge locked over
the western CONUS as downstream troffing develops over the Great
Lakes to start the longterm period. Sfc high pressure drops into the
central CONUS Wednesday afternoon along the W to NW flow aloft,
which should help keep things on the drier side. Cooler air funnels
in Wednesday into Thursday, which should keep temperatures below
normal through Saturday. As the closed low over Pacific pushes
inland Thursday night, it shifts the western CONUS ridging eastward
with it, which should help bring an increase in temps (back closer
to normal) to the UP in the latter half of the weekend into the
start of next week.
Tuesday night into Wednesday, sfc low impacting the region on
Tuesday pulls away into Quebec with weak pressure rises keeping
things a little windy through the night, especially along the
lakeshores. CAMs are suggesting light rain across the Keweenaw and
east half of the UP, but model soundings aren`t as keen on the idea,
so including some sprinkles across the Keweenaw and some drizzle
across the east. Late in the night some CAA increases, which may
bring some light rain showers, but moisture is still limited to the
sfc. By Wednesday afternoon, 850mb temps fall to near 2C, bringing
cooling temps, but moisture is generally too limited for
precipitation.
The rest of the week into the weekend, models are suggesting blo
normal height anomalies bringing temperatures 10 to 15 degrees blo
normal, at least through Friday. Widespread frost to freeze chances
will be around Wednesday night into Friday as sfc high pressure
moves into the region. The next chance for precipitation comes in
the second half of the weekend as a shortwave moves through the
central CONUS.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 758 PM EDT MON SEP 14 2020
Low pres tracking from ND tonight to Lake Superior by Tue evening
will bring increasing s to sw winds tonight into Tue. The increasing
low-level winds will transport a ribbon of low-level moisture n and
ne tonight, possible leading to a short period of MVFR cigs at KCMX
overnight. Downslope nature of the flow at KIWD may prevent a cig
from developing there. At KSAW, a more favorable upslope southerly
wind may result in developing MVFR cigs overnight falling further to
IFR late night until mid morning Tue. Otherwise, expect VFR cigs to
prevail outside of the aforementioned potential lower clouds. With a
stable sfc based layer present, low-level jet overspreading the area
will result in LLWS at all terminals overnight into Tue morning.
Gusty sfc winds to 30+kt will follow once the LLWS breaks due to
daytime heating and resultant building mixed layer.
&&
.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 329 PM EDT MON SEP 14 2020
A warm front will lift through the lake tonight, helping to develop
showers and perhaps some thunderstorms. As this front lifts through
southerly winds will increase as low pressure approaches from the
west. A tightening pressure gradient and strong low level jet will
result in near 30kt gusts over mainly the eastern portion of the
lake with some gale force gusts being possible, especially for
higher platforms. As the gradient relaxes overnight Tuesday and
winds become northwesterly, winds should lay down briefly, before
they building again to near 30kts.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
Lakeshore Flood Advisory from 10 AM Tuesday to 2 AM EDT
Wednesday for MIZ013-014.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
SHORT TERM...JP
LONG TERM...JAW
AVIATION...Rolfson
MARINE...JP
Area Forecast Discussion
National Weather Service Pocatello ID
212 PM MDT Mon Sep 14 2020
.SHORT TERM...This afternoon through Wednesday night...
Ridge of high pressure remains in place through the period. Winds
remain gusty this afternoon, with Red Flag Warnings in place, see
Fire Discussion below. Otherwise smoke and air quality appear to
be biggest impact, especially with very large fire actively
burning south of Twin Falls. Air Quality statements in place for
portions of East Idaho. See Air Stagnation Discussion below. Have
broadbrushed smoke and haze across all of East Idaho, more
aggressive than HRRR Smoke concentration fields would indicate.
Though, given the better upstream proximity to larger active fires
in Oregon and western Idaho, central mountains the most likely to
be impacted by smoke inundation. Thickness of smoke layer may have
some downward impact on daytime high temperatures over the next
few days.
.LONG TERM...Thursday through Monday.
Upper ridge amplifies Thursday and Thursday night for likely
warmest period of the week. Models continue to favor Friday timing
for progression of next cold front through East Idaho as Pacific
trough swings inland. Winds increase in relation to the front,
mainly for Friday and Saturday. Increased southwesterly flow
aloft could have a variable impact on smoke issues headed into the
weekend, but increased winds and potential onset of showers and
generally isolated thunderstorms Friday will definitely complicate
the forecast. Unsettled conditions continue through Saturday,
while cooler temperatures remain through the weekend. DMH
&&
.AVIATION...
The main concern for aviation will continue to be regional wildfire
smoke over the next several days, with otherwise "clear" skies, no
precip, and no significant wind as a ridge of high pressure remains
in control. A general SW flow will remain in place across SE Idaho
to the NW of the high pressure center, a synoptic pattern that will
generally favor continued advection of smoke into the region from
massive fires in CA/OR with potential deterioration each night under
nocturnal inversions. Fluctuations in the SW flow may actually
modify the source region of this smoke, however. For KBYI/KSUN, that
source region will likely remain CA/OR, but for KPIH/KIDA/KDIJ, the
flow may at times tap into a bit "cleaner" air from UT/NV, which
could allow for some slight improvement between this afternoon and
Tues afternoon. This idea is hinted at in the 12z HRRR smoke model
guidance. In general, we blended current vsby obs toward slow but
slight improvement in the 18z TAF package, but smoke is tricky and
forecast confidence is low. Any terminal could continue to flirt
with MVFR vsbys at times (especially KSUN), but generally 5-8 miles.
Once winds shift into the SW at KBYI this eve, local smoke from the
rapidly growing Badger Fire SW of Oakley may begin to directly
impact that terminal too. Will continue to monitor. - KSmith
&&
.FIRE WEATHER...
A Red Flag Warning remains in effect until 9 PM this eve for gusty
winds/low RH across Zones 475/476. Very dry conditions are expected
to continue through Wed, with min RH values generally 7-14%
regionwide each afternoon and very poor overnight recovery above
nocturnal inversions. In fact, mid/upper slopes may not rise above
20%. A generally SW wind flow will remain in place as well to the NW
of a high pressure center (with diurnal terrain-driven modifications
each day depending on location), but speeds will relax a bit for the
next several days (gusts generally less than 20 MPH). SO, very dry
fuels, the very low RH profile, and a Haines Index of 6 continue to
spell a very critical fire wx pattern, with winds the limiting
factor for reaching Red Flag criteria. At this time (and after
collaboration with a couple neighboring offices), we will headline
these conditions in the FWF, but hold shy of issuing a Red Flag. By
Thurs/Fri, models show reasonable agreement in a low pressure system
tracking east across the nrn Rockies and breaking down the ridge,
and the increased pressure gradient may support an increase in
winds. This may overlap with continued critical RH values Thurs,
before RHs start to moisten Fri. Model guidance is holding (perhaps
suspiciously) light on the winds at this time, so we want to watch
trends...it`s too early to tell if Red Flag criteria will be met.
Stay tuned. This low will bring a cold front by Fri night, resulting
in significantly cooler temps/higher RH values for Sat/Sun. Showers
are possible Fri/Sat as well, although early indications suggest QPF
of less than 0.20 inches. - KSmith
&&
.AIR STAGNATION...Wildfire smoke remains the primary driver for
air quality concerns across East Idaho under influence of strong
high pressure. DEQ Air Quality statements remain in place for
portions of East Idaho. As of this afternoon, very large and very
active fire south of Twin Falls producing a pronounced smoke plume
per satellite and radar imagery. Expect this plume to worsen
conditions tonight and into tomorrow, at least locally through
the Eastern Magic Valley, Lower Snake Plain, and nearby lower
elevation areas. Otherwise, central mountains in best proximity
to receiving smoke from upstream fires in western Idaho and
Oregon, and thus lower elevations have the greatest chance of
significantly lowered air quality. Expect these conditions to
continue through the week. DMH
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning until 9 PM MDT this evening for IDZ475-476.
&&
$$
Area Forecast Discussion
National Weather Service Shreveport LA
933 PM CDT Mon Sep 14 2020
.UPDATE...
Went ahead and removed pops from ongoing forecast based on latest
radar trends. Surface ridge to the north to maintain light
northeast winds overnight. Otherwise, aside from high cirrus
fingers across northeast Louisiana along the western fringes of
Sally, mostly clear skies expected through the night. Current
forecast is on track, no major adjustments at this time. /05/
&&
.PREV DISCUSSION... /issued 713 PM CDT Mon Sep 14 2020/
UPDATE...
Just sent a quick update to extend widely scattered shower and
thunderstorm wording for the next couple of hours across portions
of north Louisiana and deep east Texas as weak banding features
begin to shift west across the region. /05/
PREV DISCUSSION... /issued 638 PM CDT Mon Sep 14 2020/
AVIATION...
Mainly dry conditions to prevail across area terminals through the
forecast period ending 16/00Z. MVFR ceilings possible across all
terminal sites near daybreak with VFR conditions prevailing
otherwise. Otherwise, northeast winds around 5 to 10 knots
overnight to increase to 5 to 10 knots with higher gusts on
Tuesday. /05/
PREV DISCUSSION... /issued 300 PM CDT Mon Sep 14 2020/
SHORT TERM.../Tonight through Tuesday Night/
Diurnal instability is finally overcoming subsidence northwest of
Hurricane Sally, and isolated to widely scattered showers and
thunderstorms are quickly developing over Northeast Louisiana and
Southeast Arkansas. Additional development and movement
southwestward is expected this afternoon. The latest HRRR suggests
a few showers may develop as far northwest as Southeast Oklahoma,
but most of the convection will be southeast of a line from Lufkin
TX to El Dorado AR. The showers and storms should quickly end
after sunset with the loss of daytime heating.
As Sally very slowly approaches the Gulf coast, we`ll begin to see
increasing influences on our weather on Tuesday. Northeasterly
winds will increase to between 10 and 15 kts areawide with gusts
near 20 kts across North Central Louisiana. Good chances for
scattered diurnal convection associated with Sally are expected
Tuesday afternoon across most of our Louisiana parishes with the
exception of the far northwest corner. Similar to the last couple
of days, being this far removed from the center, showers and
thunderstorms should once again gradually dissipate during the
evening hours.
Hurricane Sally is expected to make landfall Tuesday night.
CN
LONG TERM.../Wednesday through Sunday/
Starting 12z Wednesday...As we head into the long term period,
Hurricane Sally will be in the process of moving inland somewhere
between Louisiana and the Florida Panhandle. We will see some deeper
moisture on the far western fringes of Sally, which will bring an
increase in showers and thunderstorms Wednesday afternoon. On
Thursday, Sally will continue to track towards the northeast across
Mississippi and Alabama. As Sally pushes to the northeast, an upper
trough over the Southern Plains will begin to push off to the east
as well. As the trough pushes to the east, we should see showers and
thunderstorms redevelop Thursday afternoon across the area.
Drier and cooler conditions are expected across much of the area as
we head into the weekend. Temperatures Friday through Sunday will be
up to 5 degrees below seasonable normals. Friday will see high
temperatures ranging from the lower 80s across the north to the
upper 80s to the south. On Saturday, areas along and north of I-30
will struggle to get out of the 70s, with similar conditions on
Sunday. Looks like it will be a good weekend to get out and enjoy
the weather.
33
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 73 90 72 88 / 0 10 10 30
MLU 73 90 72 88 / 10 40 20 50
DEQ 69 87 69 86 / 0 10 10 40
TXK 69 87 70 84 / 0 10 10 30
ELD 70 88 70 86 / 0 20 10 40
TYR 71 88 69 87 / 0 10 0 20
GGG 71 89 70 88 / 0 10 0 20
LFK 73 92 72 92 / 0 10 0 20
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...None.
LA...None.
OK...None.
TX...None.
&&
$$
05/20/33