Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 10/01/24
Area Forecast Discussion
National Weather Service Billings MT
646 PM MDT Mon Sep 30 2024
.KEY MESSAGES...
- Gusty NW winds decrease by evening.
- Frost or freeze possible tonight.
- Warmer/dry conditions and breezy in spots for Tuesday and
Wednesday.
- No chance of meaningful precipitation over the foreseeable
future.
&&
.UPDATE...
Extended the smoke and haze grids through Tuesday night based on
the latest HRRR guidance. Hazy skies look to become more common by
Tuesday evening. Archer
&&
.DISCUSSION...
Through Tuesday night...
Gusty post-frontal NW winds continue across the forecast area.
Highest gusts (near 50 mph) have been east of Rosebud County, but
gusts around 30 mph have persisted in the west. Strong 850mb cold
advection is shifting east of us and pressures are beginning to
fall in south central MT, so a gradual decrease in gusts should
occur thru the remainder of the afternoon. Once we get past sunset
winds will be much lighter thru the night, with drainage beginning
along the western foothills. With regard to the Elk Fire west of
Dayton, NW winds will veer to the N-NE this afternoon and become
light by sunset. Winds will shift to southerly tonight and the
drainage could result in surface smoke spreading to Dayton and
Ranchester, and possibly northward along the Little Bighorn toward
Lodge Grass and Crow Agency. Something to watch. There is an Air
Quality Alert in effect until 1pm Tuesday for Sheridan County.
Clear skies and light winds will yield a chilly night tonight...
likely the chilliest so far this fall. There is a good chance
(>70%) of a frost most places, and notoriously colder spots will
see a freeze. We are forecasting a low of 38F at the Billings
airport and 35F in the city. Take care of sensitive plants.
Tuesday will be warmer w/ less wind, but there will still be mixed
gusts on the order of 20-30 mph along the western foothills. Temps
will reach the 70s and near 80F in spots tomorrow. It goes w/o
saying that dry conditions will prevail through Tuesday night as
we remain dominated by a dry zonal flow.
JKL
Wednesday through Monday...
Dry zonal to NW flow will continue into this weekend, with normal
to above normal temperatures in the forecast. Highs will be in the
60s to 70s through Friday, and possibly up to 80F Saturday
through Sunday. The chance for precipitation through the weekend
will be negligible. Lingering gusty winds on Wednesday in the
western mountains and foothills in the 20s-30s mph will create
breezy conditions. Strong winds are not forecasted Thursday and
Friday, though an increase is possible on Saturday, as a result of
a passing shortwave. Wind gusts in the 20s-30s mph will again be
possible. To go along with the warm and windy conditions, minimum
relative humidity values will be poor throughout the extended,
15-25%. Because of this, fire weather concerns will continue,
mainly in the lower elevations where minimal rainfall has fallen
over the past few weeks.
Matos
&&
.AVIATION...
Winds will continue gradually decreasing until around 02z and
will be much lighter overnight and Tuesday. VFR will prevail
through the period, but local reductions to MVFR due to smoke from
the Elk Fire are expected near KSHR (and possibly near K00U by
early Tuesday). Slant range visibility will be reduced at times.
Archer
&&
.PRELIMINARY POINT TEMP/POPS...
Tue Wed Thu Fri Sat Sun Mon
-----------------------------------------------------------
BIL 039/077 051/075 041/065 039/075 051/079 047/078 048/079
00/U 00/U 00/U 00/U 00/U 00/U 00/U
LVM 035/079 049/076 034/067 035/079 046/078 044/078 044/077
00/H 00/N 00/U 00/U 10/N 00/U 00/U
HDN 035/079 047/075 039/066 036/076 045/081 044/078 044/080
00/H 00/U 00/U 00/U 00/U 00/U 00/U
MLS 035/075 050/070 041/064 037/073 048/078 044/073 045/077
00/H 00/U 00/U 00/U 10/U 00/U 00/U
4BQ 035/077 050/073 041/066 038/076 050/079 045/075 046/079
00/H 00/U 01/U 00/U 00/U 00/U 00/U
BHK 033/074 047/069 038/064 035/074 045/077 041/072 042/077
00/U 00/U 01/B 00/U 00/N 00/U 00/U
SHR 032/079 046/078 036/067 035/079 045/082 042/078 044/080
00/H 00/U 00/U 00/U 00/U 00/U 00/U
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...None.
WY...None.
&&
$$
weather.gov/billings
Area Forecast Discussion
National Weather Service State College PA
1115 PM EDT Mon Sep 30 2024
.SYNOPSIS...
Upper level low pressure will weaken/fill as it drifts slowly
east across the Central Appalachians tonight, before pushing
east of the area late Tuesday.
A front will move through on Wednesday and lead to drier and
sunnier conditions for the second half of the week.
&&
.NEAR TERM /UNTIL 7 AM TUESDAY MORNING/...
Regional radar loop at 03Z shows an area of light rain/drizzle
falling across the southern half of PA in a region of upper
level diffluence ahead of an upper low over the Ohio Valley.
Little change is expected overnight, as the upper low makes slow
eastward progress to near the western panhandle of WV by dawn.
Latest near term model guidance indicates an upsloping southeast
flow may cause the northern edge of the light rain/drizzle to
expand north along the spine of the Alleghenies into Elk and
perhaps Southern Mckean counties overnight. Have added ridgetop
fog to the forecast across the Southern Alleghenies based on
latest RAP and SREF prob charts.
Ensemble mean qpf overnight ranges from nothing over the
northern tier counties and Middle Susq Valley, to perhaps a half
inch on the ridgetops of Cambria and Somerset counties. Weak low
level cold advection should push readings to the mid and upper
50s in most locations by dawn.
&&
.SHORT TERM /7 AM TUESDAY MORNING THROUGH WEDNESDAY/...
The remnant of the upper low is progged to track along the Mason
Dixon Line Tuesday morning, then pass off the Delmarva Peninsula
by afternoon. Thus, expect rain to taper off to from west to
east Tuesday. However, low level moisture combined with an
upsloping southeast flow should result in lingering low clouds
and drizzle over the Central Mtns. We continue to undercut NBM
max temps Tuesday across most of Central PA, due to its warm
bias in cold air damming/easterly flow scenarios. Expect highs
to range from the upper 50s over the higher terrain of South-
Central PA, to the upper 60s over the Middle Susq Valley, where
model RH profiles support a few breaks or thin spots in the
overcast.
Model soundings remain nearly saturated from the surface to
700mb over the Central Mtns Tue night, indicating low clouds and
occasional drizzle is likely. In addition, a weak shortwave is
progged to traverse the region late Tue night, bringing a chance
of showers to the northwest part of PA.
Rising heights behind the departing shortwave signal drier and
milder conditions Wednesday overall. However, a dying occluded
front is progged to wash out over Northwest PA Wed, with a
persistent low level southeast flow ahead of it yielding
lingering stratus over most of the forecast area. A nearly
saturated sfc-850mb layer, combined with weak orographic
forcing, should result in spotty drizzle over the Central Mtns.
Similar to Tuesday, expect max temps to fall a bit short of
seasonal normals and NBM guidance, due to its warm bias in
CAD/easterly flow scenarios.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
All medium range guidance supports fair and warm weather
Thursday and Friday, as upper level ridging builds over PA. GEFS
2m temp anomalies are 5-10F above climo, translating to highs in
the 70s.
A cold front passage could produce a few showers Friday night.
However, current guidance tracks the parent shortwave and best
large scale forcing north of the region, so POPs are in the
15-30pct range. Fair and seasonable weather appears likely next
weekend, as surface high pressure builds across the state.
We have slightly undercut NBM min temps Sat night, when
conditions favor efficient radiational cooling directly under
the surface high.
The next chance of showers will come Sunday night with
the approach of another cold front. Current guidance indicates
the associated upper trough will be fairly deep and provide
enough forcing for a good chance of a light but measurable
rainfall Sun night into early Monday. Fair and cooler conditions
should follow later Monday, as surface ridging and dry air
arrive behind the front.
&&
.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
Heading into the early overnight hours, borderline MVFR/IFR
conds were found across much of central PA. The Susq Valley
(IPT/MDT/LNS) remained VFR beneath a ~4 kft cig.
Expect some degradation overnight in continued low clouds,
light/drizzle, and patchy fog. Many sites will likely return to
IFR, with the Susq Valley expected to at least dip back down to
MVFR.
Slight improvement is possible during the day on Tuesday, esp
across the north and east. However, continued east-southeasterly
flow will make it difficult to see significant improvement, and
we could see IFR conds persist across the Laurel Highlands and
the Ridge and Valley region.
More significant improvement appears in store later Wednesday
and especially Thursday.
Outlook...
Wed...AM rain/low cigs possible, then PM improvement.
Thu-Fri...Drier weather, with primarily VFR conds expected
outside of patchy morning valley fog.
Fri night-Sat...A few showers are possible. Otherwise,
predominantly VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...Lambert/Dangelo
NEAR TERM...Fitzgerald
SHORT TERM...Fitzgerald
LONG TERM...Fitzgerald
AVIATION...Evanego
Area Forecast Discussion
National Weather Service Grand Junction CO
530 PM MDT Mon Sep 30 2024
.KEY MESSAGES...
- A few storms have fired over the the southern valleys today. A
few sprinkles are expected with some gusty outflow winds
possible under and near the stronger showers and storms.
- High confidence continues of near record high temperatures
through the week.
- High pressure remains in control through the week with little
change from day to day.
&&
.SHORT TERM /THROUGH TUESDAY/...
Issued at 149 PM MDT Mon Sep 30 2024
A few storms have fired this afternoon over the southern
valleys with mostly cloud-to-cloud lightning noted, though a few
cloud-to-ground strikes have occurred as well. Looking at
available moisture and instability, the highest amounts are co-
located in that general area so this convection comes as no
surprise. Dry conditions remain at the surface across most of
the CWA so any showers or storms may produce a quick sprinkle or
trace QPF- wise. Evaporative cooling will allow some gusty
outflow winds with a few stronger gusts possible under and near
any of these cells. Again, these will remain over the San Juan
foothills and southern valleys. The rest of the CWA will see
clear to partly cloudy skies as more record high temps are
likely tied or broken. A few afternoon gusts of 20 to 25 mph
will also occur from time to time.
Little change on Tuesday though forecast moisture is expected to
decrease across the area except for a small sliver along the
NM/CO border. HRRR CAPE values are almost non-existent while the
NAMNEST does have some values around 100 to 200 J/kg. Expect
there will be some instability available but with a lack of
moisture, not too sold on any showers or storms. The NBM agrees
and gives us PoPs of 10% or less. The HRRR agrees while the
NAMNEST has very isolated convection in place for the same areas
we`re seeing convection today. For now, will hold off on any
mention of precip with more sun than clouds and those unseasonably
early October temps remaining in place.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
Issued at 149 PM MDT Mon Sep 30 2024
Model agreement remains lockstep with an elongated ridge of high
pressure anchored over the southern Continental U.S. With the polar
jet well to our north along the Canadian Border, we will wait
patiently for near record high temperatures to subside.
Unfortunately, this is going to require a ripple or two in the
longwave pattern...a seemingly small request the second week of
autumn here in the Rockies. Model phasing remains steady into
Thursday ahead of a wave that tries to drop out of the Gulf of
Alaska and come ashore in the PACNW Friday. Moisture will remain
in short supply for the CWA this week. A remnant pool of
moisture hangs on across AZ/NM, this will keep a sliver of
shower activity in the forecast Wednesday and, maybe, Thursday
on the terrain of southwest Colorado. Any showers that manage to
get going will drop some gusty outflows, but little to nothing
in the way of wetting rainfall. The PACNW wave on Friday seeds a
little hope for collapsing the ridge enough to perhaps cool
temperatures a degree or two next weekend. Precipitation looks
unlikely, but some cloud cover working through could offer some
relief as well. Unfortunately, the polar jet stays northward and
we continue to rely on weak shortwave perturbations for
sensible weather. Nonexistent moisture makes this a tall order.
In the meantime, near-record highs will continue with a chance
for a slight cooling trend headed into next week.
&&
.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 530 PM MDT Mon Sep 30 2024
VFR conditions and light terrain driven winds are expected over
the next 24 hours over eastern Utah and western Colorado as
high pressure remains in control.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...None.
UT...None.
&&
$$
SHORT TERM...TGR
LONG TERM...LTB
AVIATION...NL
Area Forecast Discussion
National Weather Service Goodland KS
1002 PM MDT Mon Sep 30 2024
.KEY MESSAGES...
- Breezy to gusty winds will continue across the area this
evening.
- Fire Weather Watch remains in effect for Yuma and Kit Carson
counties Tuesday. Near critical to locally critical fire
weather forecast for adjacent counties.
- Record/near record high temperatures anticipated for some
Wednesday.
- No rainfall is forecast for the next 7 days.
&&
.SHORT TERM /THROUGH TUESDAY NIGHT/...
Issued at 135 PM MDT Mon Sep 30 2024
Cold front continues to move across the area bringing breezy to
gusty northerly winds up around 40 mph at times to the area.
These winds will continue through early to mid evening before
the nocturnal inversion sets in and the pressure rises behind
the front stabilizes. The Red Flag Warning remains in place for
SW Nebraska; some consideration was given to expand it to
include the Colorado counties as there may be some overlap of
RH values around 15% and the continued strong winds along with
some higher values of GFDI. I opted to hold off the expansion
due to the limited number of hours where "critical" conditions
may be met. High temperatures for most will have been met by
1pm MT and we will see a steady downtrend for the remainder of
the afternoon.
For tonight, have lowered temperatures a few degrees into the
mid/upper 30s to mid 40s as radiational cooling may be strong
given a dry air mass, light winds and mainly clear skies. I do
have some concerns that some locally lower values potentially
approaching the freezing mark may be possible especially in
valleys across Yuma and Dundy counties due to dew points in the
low to mid 20s and light winds around 5-10 mph as a surface high
moves into the area around sunrise. I considered a Frost
Advisory for Yuma and Dundy counties in particular where the
lightest winds should occur but opted to hold off due to
concerns regarding the spatial extent of the frost potential,
some high clouds which may interfere with radiational cooling
and if frost would even form given the dry dew points and larger
dew point depressions. RAP has been fairly consistent bringing
in some meager low level moisture along and south of I-70
starting around 09Z-13Z Tuesday. Given how dry the low levels
are would be shocked if its anything more than a sprinkle or
two; more than likely would be virga. As a result, have nudged
up pops to around 5%.
Tuesday, the surface high slowly moves to the east keeping winds
light for most. As the high continues to move east return southerly
flow will occur across western portions of the area where some gusts
around 25-30 mph will be possible. RH values will again be in the
mid to upper teens creating some concern for fire weather conditions
especially across eastern Colorado. At this time the favored
area for multiple hours of critical fire potential lies across
western portions of those counties as a result and after
collaboration with NWS Boulder have opted to introduce a Fire
Weather Watch for Kit Carson and Yuma counties for Tuesday
afternoon. High temperatures will be more seasonal in the upper
60s to mid 70s across the area in wake of today`s cold front.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
Issued at 135 PM MDT Mon Sep 30 2024
Not much change from previous discussions regarding the extended
period. Mainly zonal upper level flow will be present for the
majority of the period. some brief periods of northwesterly flow are
possible as some ridging tries to develop across the Inter-Mountain
west towards the end of the week. At the surface some weak surface
cold fronts look to move through the area however with the first one
Thursday into Friday and another towards the end of the week into
the new work week. As of this time no impacts are expected with
these fronts.
The main talk for the week will be the continued run of above normal
temperatures as highs for most of the extended period look to
be in to the mid 80s to low 90s except for the days in wake of
the fronts. Some near record to record highs are possible
Wednesday and perhaps again Saturday. At this time confidence is
currently the highest in record highs being jeopardy Wednesday.
For more detailed information on the record highs please see
the Climate section below.&&
.AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/...
Issued at 1000 PM MDT Mon Sep 30 2024
VFR conditions are expected through the forecast period as high
pressure moves over the region. Winds, northeast around
10-15kts through 09z Tuesday, then light/variable. By 14z-15z,
becoming east-southeast around 10kts, then shifting south
10-20-kts from about 18z-19z through about 00z Wednesday.
Strongest gusts in the afternoon.
&&
.FIRE WEATHER...
Issued at 639 PM MDT Mon Sep 30 2024
After collaboration with NWS Boulder have issued a Fire Weather
Watch for Kit Carson and Yuma counties for Tuesday afternoon. A
surface high will move east through the morning allowing for
southerly winds to return to the area. Dew points will remain
low in the 20s resulting in RH values in the low to mid teens.
Winds look to gust to around 30 mph with the strongest west of
Highway 385.
&&
.CLIMATE...
Issued at 135 PM MDT Mon Sep 30 2024
Record/near record high temperatures are forecast for the
following locations Wednesday, October 2...
Goodland.....93 degrees set back in 1953
Burlington...92 degrees set back in 1997
Colby........93 degrees set back in 2006
Tribune......93 degrees set back in 2006
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...None.
CO...Fire Weather Watch from Tuesday afternoon through Tuesday
evening for COZ252-253.
NE...None.
&&
$$
SHORT TERM...Trigg
LONG TERM...Trigg
AVIATION...JN
FIRE WEATHER...Trigg/JN
CLIMATE...99
Area Forecast Discussion...Updated
National Weather Service Lincoln IL
730 PM CDT Mon Sep 30 2024
.KEY MESSAGES...
- A short period of wind gusts 30-35 mph is expected north of
I-72 Tuesday morning, immediately behind a cold front.
- There is a 20-30% chance low temperatures fall to less than 40
degrees Wednesday morning in low lying areas. If these colder
temperatures materialize, there could be patchy frost.
&&
.UPDATE...
Issued at 730 PM CDT Mon Sep 30 2024
Surface obs show the cold front extending from the northwest tip
of Missouri into north central Wisconsin, with the drier air
showing up nicely on nighttime microphysics satellite imagery.
Most of the cloudiness this evening has been hanging out east of
I-55, though some recent development has taken place west of
there as well. The front is expected to begin moving into areas
near Galesburg toward 3 am, reaching I-55 around 6 am and
southeast Illinois toward 9-10 am. Main impact in our area will be
a short period of wind gusts around 30-35 mph behind the front,
mainly north of I-72, though the gustiness drops off south of
there before midday. Lingering clouds should largely be scoured
out once the front passes.
Main forecast update was some minor adjustments to the dew point,
sky and wind grids through Thursday to incorporate the latest
trends.
Geelhart
&&
.DISCUSSION...
Issued at 150 PM CDT Mon Sep 30 2024
A cold front associated with a trough centered in Saskatchewan is
still slated to approach our area from the west by sunrise tomorrow
morning. As that front surges southeast-ward, it will outrun the
better upper level support with the trough displaced to the north
over northern MN/WI/Lake Superior. Nonetheless, the GFS suggests
it`ll maintain a remarkably tight theta-E gradient (nearly 1
degK/mile) as it crosses areas near and west of I-57 tomorrow
morning, weakening only a little as it departs the Prairie State
during the afternoon-evening. Ahead of that front, dew points are
forecast to remain in the 60s, which together with light winds and
a loss of diurnally-driven cloud cover may result in some patchy
fog formation. HREF probabilities (probs) for visibility less than
1/2 mile are around 10-25% near and east of Highway 50; NBM is
comparably less aggressive in reducing visibilities (vis) with
only 5- 10% probs for sub 1 mile vis, but thought it still worth
carrying a patchy fog mention in the forecast so that stands at
this juncture.
Circling back to the aforementioned cold front: This will bring an
abrupt end to whatever fog manages to form from the west in
locations it reaches before sunrise/surface heating (where fog will
be "burned off" from mixing). It will also bring a plunge in
dewpoints which, if you believe the 30.12z HRRR, will drop ~15
degrees in an hour and ~25 in 3 - making it feel much drier and more
Autumn-like in central IL. Also contributing to the Fall-like
feeling in the air will be the sudden increase in winds which the
HRRR suggests will gust to around 35 mph for a couple hours behind
the front, where the sharpest pressure rises and briefly enhanced
subsidence (from cold air advection, "CAA") will contribute to
momentum transfer. These winds will be the strongest across our
northwest counties, closer to the trough and thus beneath stronger
winds aloft. West of I-55, NBM suggests 50-70% chances for wind
gusts greater than 35 mph tomorrow morning, while further east those
probs taper to less than 30%; the chance of hitting Wind Advisory
criteria (45 mph) anywhere, however, remains less than 10%, so
headlines will not be necessary. Given the perpetual turbulent
mixing of the lower atmosphere by these gusty winds (which will
still be gusting to 25+ mph throughout the afternoon given lack of
clouds and hence deep mixing) and the associated cool advection from
the northwest, our highs tomorrow will be nearly 10 degrees cooler
than today (and more seasonable) - low 70s near and west of I-57.
With a lack of clouds Tuesday night into Wednesday morning, if winds
should go slack near sunrise, it could be quite cool with lows in
spots reaching the 30s. NBM certainly thinks so, with probs as high
as 20-40% in rural, low spots (especially near the IL River Valley)
for min temps less than 40 degF. Can`t rule out patchy frost if this
manages to materialize; we`ll keep an eye on trends for winds and
cloud cover tomorrow night, but at this time it seems it`d be too
localized for a frost headline.
After welcoming October with another taste of Fall, temps will
rebound by Thursday as h5 heights gradually rise behind the
departing trough and zonal flow overspreads the Midwest once again.
Highs in the mid 70s to low 80s are forecast Thursday through
Sunday, Thursday currently looking like the warmest day. Dry
conditions are expected the remainder of the week, but a slight
chance of precip enters the picture late Saturday night into Sunday
as some guidance, including the deterministic ECMWF, brings a
compact upper trough through the Great Lakes and precip attempts
to form along its trailing cold front as it sweeps across the Ohio
Valley. If warm advection is strong enough ahead of this front,
we should be able to get enough moisture, and consequently
instability, to even get some thunderstorms given the potential
wind shear with this system. We`ll keep en eye on this system,
though severe potential seems minuscule at this time.
Bumgardner
&&
.AVIATION... (For the 00z TAFs through 00z Tuesday Evening)
Issued at 614 PM CDT Mon Sep 30 2024
Main aviation concern will be with the winds Tuesday morning, as
a sharp cold front moves across central Illinois between 11-14Z.
Light and variable winds ahead of it will quickly switch to the
north-northwest, with a period of gustiness around 25-30 knots
into midday. Gusts begin to back off some early afternoon, but
sustained speeds will remain 10-15 knots.
Ceilings near 4000 feet will prevail in eastern Illinois a good
portion of the night, scattering out with the passage of the
front. Latest HREF shows about a 30% chance of MVFR ceilings at
KCMI around 12Z immediately ahead of the front, but it should not
last long if it does pan out.
Geelhart
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Area Forecast Discussion
National Weather Service North Platte NE
655 PM CDT Mon Sep 30 2024
.KEY MESSAGES...
* Cooler temperatures return to the region on Tuesday before more
seasonal temperatures return through the weekend.
* No precipitation is expected with dry conditions prevailing
through the weekend.
* Near-critical fire conditions are expected Tuesday and Wednesday
across much of western and north central Nebraska due to low
humidity and strong winds.
&&
.UPDATE...
Issued at 655 PM CDT Mon Sep 30 2024
Looking at the latest HRRR guidance, am more concerned about
lighter winds in the NW Sandhills and northeastern Panhandle
overnight. With forecast lows in the lower 30s and lighter
expected winds, feel more confident in frost headlines for
Sheridan and western Cherry county. We will have some dry air to
overcome for frost formation as current dew points in NW
Nebraska are in the upper teens. With the expected degree of
dry air, will keep the frost mention patchy.
&&
.SHORT TERM /THROUGH TUESDAY NIGHT/...
Issued at 228 PM CDT Mon Sep 30 2024
A quiet weather pattern will remain in place through the short term
and into the foreseeable future. Conditions will remain dry through
Tuesday as strong high pressure remains over the central US. With
the passage of the cold front this morning, temperatures will drop
significantly from the past several days. Highs tomorrow will only
rise into the mid 60s to low 70s. For overnight lows tonight,
temperatures will drop into the 30s for most locations. A few
isolated locations across northern Nebraska could even see a low dip
into the upper 20s. Would not be surprised if some patchy frost
develops across the Sandhills and into the Pine Ridge where these
colder temperatures are expected. However, due to slightly stronger
winds and drier air overnight, no frost headlines have been issued.
Tuesday night lows also remain cooler, but will only drop into the
40s, which is near normals for this time of year.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
Issued at 228 PM CDT Mon Sep 30 2024
Quiet and dry conditions continue through the end of next week as
strong upper level ridging gives way to zonal flow. Outside of some
warmer days on Wednesday (mid to upper 80s) and Saturday (mid 80s),
temperatures remain near normal (in the mid 70s) through next
weekend. While it`s possible to see these temperatures rise a bit
over the next few days, the zonal flow will keep any major chances
of warm air advection from infiltrating the region.
&&
.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 610 PM CDT Mon Sep 30 2024
North to northwest winds will remain gusty of 25 to 30 kts
through shortly after sunset before subsiding and becoming light
and variable overnight. VFR conditions prevail across western
and north central Nebraska through the period.
&&
.FIRE WEATHER...
Issued at 403 AM CDT Mon Sep 30 2024
Fire weather concerns return to the region for Tuesday and Wednesday
as RH values drop and winds increase. Near-critical fire conditions
are expected both days affecting much of the area.
For Tuesday, near-critical fire conditions are expected with the
lowest humidity values being across the Panhandle and portions of
northern Nebraska. Afternoon RH values will drop to 15 percent or
below with southerly winds gusting up to 20 to 25 mph. While it will
be close, the strongest winds up to 30 mph are not expected to be
correlated where the lowest RH values will be located. In addition,
much cooler, below normal temperatures, are expected on Tuesday,
helping to keep widespread fire concerns at bay. Have opted to hold
off on any fire headlines this issuance, however, fuels are ready to
burn, and a headline may still be raised overnight.
For Wednesday, near-critical fire conditions are expected once again
as humidity drops to near or below 15 percent in the afternoon.
However, winds are anticipated to stay below 20 mph keeping much of
our area from reaching widespread critical fire conditions. Will
continue to monitor as the latest data comes in for Wednesday.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning until 9 PM CDT /8 PM MDT/ this evening for
NEZ204-206-208>210-219.
Frost Advisory from 3 AM to 9 AM MDT Tuesday for NEZ004-094.
&&
$$
UPDATE...Buttler
SHORT TERM...Kulik
LONG TERM...Kulik
AVIATION...Viken
FIRE WEATHER...Kulik
Area Forecast Discussion
National Weather Service Memphis TN
919 PM CDT Mon Sep 30 2024
...New UPDATE...
.UPDATE...
Issued at 918 PM CDT Mon Sep 30 2024
Temperatures around the Mid-South range from the upper 60s to
lower 70s under partly to mostly cloudy skies. Patchy fog is still
forecast to develop this evening, and could become dense across
portions of western Tennessee. Latest statistical and hi
resolution guidance is most suggestive that this potential will
develop toward sunrise, although dense fog development could
occur earlier in areas where radiational cooling is most
efficient. While current trends do not support the issuance of a
dense fog advisory yet, the potential will continue to be
evaluated and may be issued when needed.
Otherwise, isolated showers will be possible ahead of a
southeastward moving cold front tomorrow. Have made minor changes
to PoPs, otherwise the forecast is in good shape with no other
changes planned or needed.
JPR
&&
.SYNOPSIS...
Issued at 300 PM CDT Mon Sep 30 2024
Patchy fog will be likely overnight with leftover soil moisture.
High pressure will begin building over the region tomorrow, ahead
of a cold frontal movement. Benign weather will prevail over the
next seven days with near normal temperatures with highs in the
mid 70s to mid 80s and lows in the 50s to lower 60s.
&&
.DISCUSSION...
(This evening through next Sunday)
Issued at 300 PM CDT Mon Sep 30 2024
Benign weather is present across the Mid-South this afternoon
with current temperatures in the upper 70s to lower 80s as a
stubborn stratus deck continues to linger with mostly light and
variable winds at the surface. An upper level low pressure system
continues to trail east, currently centered over the Kentucky and
West Virginia border, resulting in possible isolated shower
development through sunset today. This upper low will continue to
weaken and move east as we head into the evening hours. Increased
soil moisture from this lingering upper level low will lead to
patchy to possible widespread fog development across the entire
area overnight. A Dense Fog Advisory may be needed tonight with
decreased visibilities, though will leave this decision to the
evening crew, if warranted. Fog should lift by daybreak as winds
begin to increase slightly.
Ridging will begin slowly building in from the west tomorrow
afternoon, drying us out and warming us up slightly. In this
transition period, isolated shower development will be possible
tomorrow afternoon with extra lift from a weak shortwave that
looks to set up over the Missouri Bootheel. Temperatures will
climb slightly tomorrow with highs in the low 80s across the area.
A cold front will begin pushing northwest to southeast, across
the Mid-South Wednesday morning, decreasing temperatures slightly
into the mid 70s to low 80s. A dry airmass will follow this
leading cold front, resulting in continued dry conditions across
the region. Zonal flow aloft and surface high pressure will begin
moving over the area Thursday, warming us up slightly with highs
in the mid 80s Friday.
Ensemble guidance denotes another cold front moving across the
area Friday evening, increasing dewpoints out ahead of it with
dry, slightly cooler air following it. As dewpoints increase ahead
of this secondary front, isolated shower development will be
possible, though non-mentionable PoPs were carried due to
uncertainty. Temperatures will once again decrease into the upper
70s to lower 80s. The latest 8-14 day outlook has us staying near
normal, in the upper 70s heading into mid October.
AEH
&&
.AVIATION...
(00Z TAFS)
Issued at 643 PM CDT Mon Sep 30 2024
Patchy fog and low stratus clouds remain the primary aviation
concern overnight. 12Z HREF guidance mean depicts IFR/LIFR
coverage mainly near MKL. Latest HRRR has trended more pessimistic
over west TN and north MS with respect to VSBY after 06Z.
Relative to last night, northerly winds off the deck will
stronger (15KT versus 5KT at FL020). This may result in just
enough mixing of dry air aloft to limit surface VSBY reduction.
PWB
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...None.
MO...None.
MS...None.
TN...None.
&&
$$
PUBLIC FORECAST...AEH
AVIATION...PWB
Area Forecast Discussion
National Weather Service Marquette MI
823 PM EDT Mon Sep 30 2024
.KEY MESSAGES...
- Cold front passing over the UP tonight to bring light rain
for most (but not all). Wind gusts overnight up to 30 mph,
higher potential along Lake Superior.
- Gusty west/northwest winds upwards of 35 mph possible (40-60%
chance) over and along Lake Superior Tuesday. Winds shifting
to the southwest remain breezy for Wednesday.
- There could be some limited to elevated fire weather concerns Tuesday
through Thursday as min RHs could dip to or below 30 percent.
The day of greatest concern is Wednesday as min RHs are
expected to get below 30 percent and a low-level jet moves
overhead.
- Frost possible early Friday and Saturday mornings in the interior areas.
- Our next rain chances don`t look to return until at least late this
week/next weekend.
&&
.SHORT TERM /THROUGH TONIGHT/...
Issued at 302 PM EDT Mon Sep 30 2024
GOES-16 water vapor imagery shows a very dry airmass over Upper
Michigan and Lake Superior this afternoon while RAP Analysis shows a
surface trough associated with a cold front passing through
Minnesota. This cold front is draped south from a 988mb low pressure
approaching the western shores of Hudson Bay. Enhanced southerly
flow ahead of this trough has allowed for some warmer temperatures
over the UP today with the high temperature at MQT already up to 73,
and some southerly downslope areas could touch 80 today.
Overnight, the cold front to the west will pass over the UP going
from west to east. CAMs show a broken line of showers passing
through the UP in the overnight period, but it is not a given that
everywhere will see rain as total PoPs from the HREF are only about
50% in the west, though some reinvigoration of showers is expected
in the east in the early morning hours with about a tenth of an inch
of precip expected. The bigger impacts will come in the winds, with
rapid pressure changes and strong cold advection behind the front
allowing for stronger winds to mix down to the surface. HREF mean
wind gusts behind the front at up to 30 mph with some higher wind
gusts possible along Lake Superior. The Euro ensemble mostly concurs
with this, but does highlight up to 50% chances of the Keweenaw
Peninsula seeing gusts exceeding 40 mph overnight, and those
probabilities have trended upwards with each of the last 5 model
runs. No land wind products are expected at this time. The cold
advection behind the front will contribute to clearing skies and
cooler air overall as lows fall into the 40s for all except the
immediate shorelines.
&&
.LONG TERM /TUESDAY THROUGH MONDAY/...
Issued at 412 PM EDT Mon Sep 30 2024
Rainfall for the most part leaves our area Tuesday morning, although
there is a slight chance (10-20%) that we could see some lake-effect
sprinkles at times in the NW wind belts throughout the day (mainly
over the east). Afterwards, winds pick up again Wednesday as a low-
level jet moves overhead in response to a shortwave over northern
Ontario. This could cause some elevated fire weather concerns
Wednesday, as min RHs are expected to get below 30 percent in some
of the interior areas. Expect temperatures to be around normal for
Tuesday, and to increase to above normal once again by the middle of
the week. However, the temperatures are not expected to be as warm
as they have been the past several days and today. Another cold
front looks to move through Wednesday night, but guidance is keeping
us dry due to the antecedent dry air and high pressure ridging
building in behind it from the Northern Plains. Our next best chance
for rainfall doesn`t look to occur until at least the end of this
week.
As the last of the rainfall associated with the cold front ends over
the east Tuesday morning, expect sunny skies to return to the area,
in addition to some breezy northwesterly winds behind the front; we
could see some spots near Lake Superior gust up to as high as 35 mph
in the morning hours. Given the dry air via the ridging moving back
in behind the front, we could see some limited fire weather concerns
in the south central as min RHs approach 30 percent. However, the
cooler temperatures behind the front could help to somewhat
alleviate this concern Tuesday. With temperatures sharply dropping
behind the cold front (highs only getting into the upper 50s to low
60s), we could see a few lake-effect clouds and possibly a few lake-
effect sprinkles in the northwest wind belts throughout the day,
mainly over the east where there will be more moisture flux from
Lake Superior given the longer fetch. However, with model soundings
showing a layer of dry air up to 5 thousand feet, lake-effect
rainfall will have a hard time reaching the surface. Therefore,
while there is about a 10 to 20% chance of seeing some lake-effect
sprinkles over the northwest wind belts Tuesday, any appreciable
precipitation amounts should be next to nothing.
Moving into Tuesday night, mid to upper level cloud cover looks to
move into our area as a shortwave over northern Ontario begins to
lift. While we are very likely to remain dry (90% likelihood), the
cloud cover may provide just enough insulation to prevent frost from
forming over the interior areas. Therefore, while there is still a
small chance (10-20%) of seeing patches of frost form Tuesday night,
given the little bit of insulation from the cloud coverage, I think
that will be enough to prevent its formation. As for lows, expect
them to range from the mid 30s in the interior to the low to mid 40s
along the Great Lakes.
A low-level jet passes overhead Wednesday and could bring some
breezy southwesterly winds over the U.P. throughout the day. In
addition, with min RHs getting down below 30 percent in some spots
and high temperatures of the mid 60s to around 70 expected, we could
very well see some elevated fire weather concerns Wednesday. This
situation will need to be monitored closely, as this weather setup
could help in increasing wildfire spread. While a cold front looks
to push through the area Wednesday night, no precipitation is
expected with it as the mid and lower levels will remain dry and the
better moisture will be further north in northern Ontario. More dry
conditions could be seen Thursday too as high pressure ridging
continues over the area. However, with winds being weaker, the fire
weather threat doesn`t look to be as significant.
Moving into late this week and this weekend, we could see some rain
chances starting late Thursday night/Friday (mainly the east) as the
GFS and Canadian as portray a shortwave digging through the Upper
Great Lakes. However, with high pressure ridging building in
directly behind this shortwave and the uncertainty of the
shortwave`s strength and location, the certainty of the rain chances
is rather small at this time (15-20%). Moving into late this
weekend, model guidance does have better convergence on a solution
bringing rainfall to the area. However, given that this is several
days out and there are numerous errors in the models at this time,
confidence in these rain chances are rather low (20 to 40% chance).
Besides the rain, we could see some frost develop in the interior
areas early Friday and Saturday mornings. Agricultural interests may
want to take note and prepare beforehand, as the frost could damage
unprotected crops.
&&
.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 823 PM EDT Mon Sep 30 2024
VFR conditions for duration of the TAF period despite cold front
passage. The main threat with the front will be the strong
southerly winds ahead of it through this evening, then northwesterly
in its wake early tonight. Gusts of 25 to 30 kt will be possible
along with a brief period of LLWS, especially at CMX around 03Z Tue.
Wind gusts will subside by Tue 12Z at IWD and SAW, but will persist
into this afternoon at CMX. Will also include VCSH mention at CMX
and SAW early Tuesday morning, but little to no impact is expected
with that.
&&
.MARINE...
Issued at 412 PM EDT Mon Sep 30 2024
Southerly winds of 20 to 30 knots from the tip of the Keweenaw to
the eastern Lake Superior buoy this afternoon and evening increase
to northwest gales up to 35 knots behind a cold front late tonight,
before the winds weaken to 20 to 30 knots Tuesday behind the front;
therefore a Gale Warning has been issued for all of the open lake
save for the far east from 11 PM EDT tonight to 8 AM EDT Tuesday. As
ridging builds back over the area Tuesday afternoon, the winds begin
to die back down, becoming 20 knots or less again by Tuesday
evening. However, with a low-level jet moving in from the west late
Tuesday night, winds begin building from the southwest, eventually
becoming gales up to 40 knots by Wednesday morning mainly over the
western half of the lake; NBM probabilities show that there is about
a 30 to 40% chance that gale-force gusts up to 45 knots are possible
mainly around Isle Royale around midday too. Expect another gale
warning to be issued for this event once the first gale event is at
least underway. As the low-level jet leaves the area late Wednesday,
expect the winds to weaken to around 20 knots as they become more
west and northwesterly. However, the westerly winds could gust back
up to 20 to 30 knots over the western lake Thursday as a developing
shortwave moves in from the west. Winds generally slacken to 25
knots or less Friday into early this weekend as high pressure once
again rebuilds across our area.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
Gale Warning until 5 AM EDT /4 AM CDT/ Tuesday for LSZ162-
241>244-263-264.
Gale Warning from 2 AM to 8 AM EDT Tuesday for LSZ249-250-265-
266.
Lake Michigan...
None.
&&
$$
SHORT TERM...GS
LONG TERM...TAP
AVIATION...GS/TDUD
MARINE...TAP
Area Forecast Discussion
National Weather Service Tampa Bay Ruskin FL
826 PM EDT Mon Sep 30 2024
...New UPDATE, AVIATION...
.UPDATE...
Issued at 825 PM EDT Mon Sep 30 2024
A band of deep tropical moisture over the Nature Coast allowed
for scattered to numerous showers and storms to stream onshore
there this afternoon, while ridging aloft and a drier air mass
kept conditions largely rain free across the central portions of
the forecast area. Over southwest Florida, a surge of moisture
from the south allowed for a few showers and storms to develop
this afternoon, and HREF is indicating that some of these showers
could hold together overnight and lift north towards the Tampa Bay
by early morning, although the HRRR keeps conditions drier.
Rain chances have been tweaked slightly for the next few hours to
keep up with radar trends and show the potential for these
showers along the southwest Florida Coast. Otherwise, the forecast
looks on track through the first couple of periods, with somewhat
wetter conditions expected Tuesday afternoon across much of the
area.
&&
.AVIATION...
(00Z TAFS)
Issued at 825 PM EDT Mon Sep 30 2024
A couple of stray showers or storms are continuing to occasionally
impact area terminals, mostly over southwest Florida and the
interior. Overnight, a few showers could linger around southwest
Florida area terminals through after midnight, gradually lifting
north and could impact Tampa Bay area terminals by around day
break. More widespread thunderstorms are expected Tuesday
afternoon, potentially disrupting flight categories at area
terminals by around 17-19z.
&&
.MARINE...
Issued at 244 PM EDT Mon Sep 30 2024
High pressure in the southwest Atlantic will maintain light flow
with winds less than 10 kts and seas less than 2 feet through the
middle of the week. A cold front then moves through the area
Wednesday into Thursday and this will cause winds to shift
easterly and increase by the end of the week. In addition, a
disturbance could move into the southern Gulf of Mexico by the
end of the week and the National Hurricane Center has given this
feature a 40% chance of development within the next 7 days so
interests in the Gulf waters of west-central and Southwest Florida
should monitor the progress of this system.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 78 89 75 89 / 20 70 40 60
FMY 77 92 76 92 / 40 30 20 50
GIF 78 92 75 91 / 20 70 40 60
SRQ 77 90 75 91 / 20 60 40 50
BKV 74 90 72 89 / 10 70 30 60
SPG 80 90 79 89 / 20 60 40 50
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...None.
Gulf waters...None.
&&
$$
UPDATE/AVIATION...Fleming
MARINE...Giarratana