Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 08/31/23
AREA FORECAST DISCUSSION
National Weather Service Bismarck ND
836 PM CDT Wed Aug 30 2023
.UPDATE...
Issued at 827 PM CDT Wed Aug 30 2023
Storms continue over western ND this evening. Will monitor as
needed.....
UPDATE Issued at 653 PM CDT Wed Aug 30 2023
Area of thunderstorms looks to be developing over western McKenzie
county. This is an area of diminishing Cinh, near 1500 j/kg ml
cape 35 knots of shear. Will continue to monitor. Made some minor
adjustments to pops based on this development.
UPDATE Issued at 501 PM CDT Wed Aug 30 2023
A band of showers with some occasional thunder is working it`s way
across central ND this afternoon. This is in an area of little
cape or shear, so do not any strong storms associated with this
area. Another area of thunderstorms was situated over southeast
Montana, and may approach the area later tonight. The main
question late this afternoon/early evening is whether convection
will fire along the ND/MT border. There is an area of cu
developing there, within an area of surface convergence but at
this time it looks shallow with little vertical development. There
is some modest cape and decent bulk shear if anything would
develop but as of late afternoon the area remains capped. We made
some updates to pops for the area of convection moving through
central ND and the lack of convection currently in the west.
&&
.SHORT TERM...(This Evening through Thursday)
Issued at 305 PM CDT Wed Aug 30 2023
An upper level disturbance and associated surface low will bring
chances for showers and thunderstorms through tonight, with breezy
conditions, and lingering smoke.
Surface low is starting to take shape across the region extending
a stationary or weak warm front across western ND. The developing
low has brought some breezy conditions this afternoon, although
these winds have not approached advisory criteria quite yet. Some
low RH and breezy wind in the west could bring some near critical
fire weather conditions, although fuels remain green. The winds
have wrapped in surface smoke which continues to linger across
much of the CWA. There also has been a weak thunderstorm or two
along this boundary. This might be aided by a strong low level
jet. This evening through tonight, much of the same is expected as
the low and associated wave move eastward. Showers and
thunderstorms should become more scattered across the region. The
severe weather potential still remains low. The better instability
is mostly non surface base, yet shear parameters remain high.
DCAPE also looks to go on the increase through tonight. With
skinny overall cape the hail threat still appears to be low,
although some curved hodographs could promote some weak rotation
in storms. The bigger concern for any storms that are stronger and
more organized will be a low severe threat. DCAPE being on the
rise, and high amounts shear, could combined with strong winds in
the low level jet and bring an isolated severe wind gust. The
threat is still too low to confidently mention although remains
possible. Otherwise look for overnight lows in the 50s (behind a
weak cold front) west to 60s east. Smoke could also linger in
central and easter areas tonight, although the HRRR Smoke does
start to diminish surface smoke later tonight. Fog chances look
limited tonight, although there is brief period of calming winds
and high RH in the north.
Thursday, initial showers and thunderstorms should push eastward
Thursday morning. An upper level low skirting across the north
could bring some wrap around showers through the day. Breezy
southerly winds will become westerly behind a weak cold front on
Thursday. This front will also bring slightly cooler temperatures
to most areas in the 70s and 80s. RH values could lower to near 30
percent Thursday afternoon. With fuels still being fairly green,
fire weather concerns are minimal for Thursday.
.LONG TERM...(Thursday Night through Wednesday)
Issued at 305 PM CDT Wed Aug 30 2023
Look for warming conditions through the start of Labor Day
weekend. Labor Day into next week could be cooler with chances for
showers and thunderstorms.
Winds lessen Thursday night, with precipitation also coming to an
end. Temperatures look to be near to slightly above normal. Friday
through Sunday looks to see ridging being the main weather maker.
This combined with a gradual shift to southwest flow will bring
warming temperatures each day. Look for warm temperatures in the
upper 80s to upper 90s each day. The southwest flow should provide
for lower dewpoints limiting heat advisory concerns. The lower RH
values could bring some increased fire concerns, although winds
this weekend overall look to be light. Labor Day into Tuesday of
next week still has a strong signal for a large trough moving
through, although timing still remains uncertain. Cooler
temperatures will accompany passage of this system, along with the
return for chances of showers and thunderstorms. Right now the
chances for severe weather look low, although perhaps a strong
storm or two may accompany the passage of this system. Breezy
winds may also return especially to start the week. Ridging then
looks to be in place for Wednesday, limiting chances for
precipitation and may bring some slightly warmer temperatures.
&&
.AVIATION...(For the 00Z TAFS through 00Z Thursday Evening)
Issued at 653 PM CDT Wed Aug 30 2023
A frontal boundary will move across the area tonight with strong
southeast winds ahead of the boundary, turning westerly as the
boundary passes. Scattered showers and thunderstorms are also
possible along/behind this boundary tonight and could bring some
brief MVFR visibilities in heavier rain showers. The TAF sites
most likely to see convection are KXWA and KDIK this evening and
KMOT later tonight. At KBIS and KJMS strong winds aloft will
necessitate the need for a period of LLWS this evening into the
overnight hours, but the probability for showers and thunderstorms
is lower at these sites. Westerly winds will increase late in the
forecast period.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE...NH
SHORT TERM...Anglin
LONG TERM...Anglin
AVIATION...TWH
Area Forecast Discussion
National Weather Service Cheyenne WY
531 PM MDT Wed Aug 30 2023
.SHORT TERM...(This evening through Thursday)
Issued at 334 PM MDT Wed Aug 30 2023
Latest GOES imagery shows cumulus along a boundary from Cheyenne
extending northeast towards Scottsbluff with a 10-15F degree dew
point gradient. So far, have not seen too many serious attempts at
deeper convection, but recent images have shown a few better
attempts clustered around Torrington/Scottsbluff. CAMs have
trended more towards initiating a few showers and storms along
this boundary around 23-01z, mainly over the southern NE Panhandle
where latest RAP shows ~500 J/kg of MLCAPE with fair dry boundary
layers and high LCLs. Main hazards will these storms could be
gusty outflow winds in the vicinity through early this evening.
West of this boundary, dry downsloping winds in addition to deep
mixing of winds aloft are leading to elevated fire weather
conditions with Red Flag Warnings in effect until 8 PM MDT for areas
where fuels are ready. Latest observations have shown numerous sites
along the I-25 corridor with wind gusts 30-40 mph while farther west
has seen 50 mph wind gusts near the Elk Mountain area of I-80. These
winds should begin to drop off after sunset. See the Fire Weather
discussion below for further details.
Thursday will be another warm, dry day across southeast WY and the
NE Panhandle as a secondary trough passes to the north leading to
gusty winds along eastern foothills of the Laramie Range as well as
across parts of Carbon Co through early afternoon. Tight mslp
gradients along the Laramie Range with a lee trough will aid in 30
mph wind gusts at the surface with 30-35 kt westerlies at 700mb
passing through. However, winds will turn lighter throughout the
afternoon as the upper level trough to the north passes east
relaxing mslp gradients, but dry conditions are still expected
across east-central WY leading to elevated fire weather conditions.
Looking at afternoon highs reaching the upper 80s to 90s with 700mb
temps remaining around 14-18C.
.LONG TERM...(Friday through Wednesday)
Issued at 334 PM MDT Wed Aug 30 2023
A wet weekend and start to the week look likely for the region
with a cooling trend expected throughout the long term. There is
significant disagreement between the GFS and ECMWF on the
progression of an upper-level system Sunday and Monday. Drier
conditions return by Tuesday.
An upper-level ridge sits over the central CONUS with a strong
trough over the Pacific Northwest. Southwest flow dominates the
atmosphere throughout the day Friday with several 500mb vorticity
maximums traversing through the ridge. With southwesterly flow
throughout the atmosphere, monsoonal moisture advects into the
region with PW values increasing to nearly an inch across eastern
portions of the CWA with 0.7-0.8in PW values further west.
Southwesterly flow supports upslope flow over the higher terrain of
Carbon and Albany counties. SBCAPE will be low, between 200 and 300
J/kg, but with upslope flow and moisture in the region diurnal
convection looks to develop over the higher terrain on Friday. Kept
chance PoPs in for the southwestern portion of the CWA. With the
positioning of the upper-level ridge, Friday looks to be the warmest
day in the long term. Highs west of I-25 expected to be in the upper-
70s to upper-80s, with highs east of I-25 in the upper-80s to upper-
90s across the Panhandle.
On Saturday the ridge axis continues to move off to the east as the
upper-level trough over the Pacific Northwest begins to dig
southerly towards central California. A similar set up is expected
for Saturday with southwest flow and moisture advection continuing
over the CWA. Several vorticity maximum progress through the 500mb
flow and over the area during the day. PW values remain around an
inch for eastern portions of the CWA and between 0.7 and 0.8 inches
in the western CWA. Once again, southwesterly flow at the surface
promotes upslope across the higher terrain and initiates diurnal
convection. SBCAPE values are lower than Friday, so kept PoPs
slightly lower than Friday. Temperatures cool slightly on Saturday
as the upper-level ridge moves out of the area.
By Sunday, the GFS and ECMWF start to diverge significantly in
regards to the upper-level pattern. The GFS continues to progress
the upper-level trough east and positions it over Utah by Monday
morning. On the other hand, the ECMWF ingests the upper-level trough
into the upper-level flow resulting in a very broad trough over much
of the Pacific Northwest. By Monday afternoon, the GFS suggests the
upper-level trough becomes negatively tilted as it digs across
southwest Wyoming, while the ECMWF keeps a broad, neutral trough
over Idaho. The evolution of the two models continues to diverge as
the GFS takes the negatively tilted trough through the CWA and off
to the northeast by Tuesday afternoon, while the ECMWF suggests a
positively tilted trough passes just north of the CWA on Tuesday
afternoon. Overall, if the GFS solution occurs, widespread
precipitation and potentially some stronger storms may be possible
for Sunday and Monday. If the ECMWF solution occurs, minimal
precipitation is expected for much of the CWA. Precipitation looks
likely to start the week as both models suggest some precipitation
for the region, but the exact amount and coverage are unknown at
this time. Trends in the ECMWF and GFS will need to be monitored to
determine which solution is the most likely. Despite the
disagreement between the GFS and ECMWF, a cooling trend is expected
Sunday through the remaining long term period with drier conditions
likely by Tuesday and Wednesday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 528 PM MDT Wed Aug 30 2023
Dry westerly flow aloft will occur. Skies will be mostly clear.
Sufficient pressure gradients will produce wind gusts to 33 knots
at all terminals except Scottsbluff until 03Z, with gusts from
22 to 30 knots at the Wyoming terminals after 16Z Thursday.
&&
.FIRE WEATHER...
Issued at 334 PM MDT Wed Aug 30 2023
Critical fire weather conditions are ongoing and expected to
continue through this afternoon for east-central WY and the North
Snowy Range Foothills. Douglas has been reporting wind gusts up to
37 mph and RHs as low as 11 percent since noon while the North
Snowy Range Foothills continues to see downsloping winds gusting
around 40-50 mph. Near-critical fire weather conditions are
possible again Thursday afternoon, especially closer to the North
Laramie Range with more downsloping winds. However, looks like
winds will weaken in the afternoon which would limit the potential
overlap of critical RH and winds. Therefore, decided to hold off
on any Fire Weather headlines for the time being. Precipitation
chances begin to increase late this week into the weekend
decreasing fire weather concerns for southeast WY, but remain dry
over the NE Panhandle until Monday.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...Red Flag Warning until 8 PM MDT this evening for WYZ417-418-427.
NE...None.
&&
$$
SHORT TERM...MB
LONG TERM...AM
AVIATION...RUBIN
FIRE WEATHER...MB
Area Forecast Discussion
National Weather Service Dodge City KS
508 PM CDT Wed Aug 30 2023
...Updated Aviation Section...
.SHORT TERM...(This afternoon through Thursday night)
Issued at 1200 PM CDT Wed Aug 30 2023
Midday infrared satellite imagery depicted a perfectly clear sky
across all of Kansas and adjoining areas. Haze originating from
Canadian wildfire smoke reduced visibility noticeably around
sunrise this morning, but surface observations show visibility
returning to normal as of midday, with a general opaqueness to the
sky. Vertically integrated smoke forecasts from the last several
HRRR iterations keep most of the haze/smoke across central Kansas,
at least east of Dodge City, through tonight, so opted not to
include smoke/haze in the weather grids. Otherwise, the quiet late
summer weather continues, with full sunshine, light southeast
winds, and peak heating temperatures in the lower 90s.
Clear and quiet tonight with a light south wind prevailing. Much
stronger flow at 850 mb will keep the boundary layer more mixed
through sunrise, holding temperatures several degrees warmer
compared to Wednesday morning, in the upper 50s and lower 60s.
Continued sunny, hot and dry Thursday beneath the northeast
quadrant of the dominant midlevel anticyclone centered over
New Mexico by 7 pm. Models show a net warming of 2-3C at 850 mb
Thursday, supporting mid to upper 90s in the afternoon. In a
continued very subsident regime, very few if any clouds are
expected. Lee troughing along the I-25 corridor will tighten the
southerly pressure gradient after 10 am Thursday through the
afternoon, delivering the first windy day in quite some time. 12z
NAM progs a mslp gradient of 8 mb across the DDC CWA at 4 pm
Thursday, supporting south winds of 20-30 mph.
.LONG TERM...(Friday through Wednesday)
Issued at 200 PM CDT Wed Aug 30 2023
Key Messages:
-The entire forecast is dry through next Wednesday September 6th.
-Unseasonably hot afternoons will prevail Friday through Labor
Day.
-The risk of wildfires will increase over the Labor Day weekend.
The heating trend will continue Friday, as the core of the
subtropical heat dome ridge moves northeast, back over SW KS.
Again, expect few if any clouds with strong subsidence. Models
tack on another 1-2C at 850 mb for the first day of September,
with most locations within a few degrees of 100 at peak heating.
Lee troughing will maintain south winds of 20-30 mph with higher
gusts, with a windy dry heat (blow dryer effect) expected.
Ridge remains parked over Kansas Saturday, with models again
showing the atmosphere becoming progressively hotter each day.
NBM initialization appeared a few degrees too cool, so
collaborated with neighbors and again increased to the
NBM 90% ile. As such, afternoon temperatures of 100-105 will be
common, near record levels for September 2nd. The good news:
1) this will be a very dry heat, with dewpoints as low as the 40s
allowing for heat indices well less than air temperatures, and 2)
south winds will remain elevated, maintaining the effect of
evaporative cooling for those outdoors. Heat advisories will not
be required. Still, triple digit temperatures are far from normal
for early September, and care for livestock, pets, outdoor
workers, and the elderly is encouraged.
12z GFS/ECMWF and their ensemble means keep the midlevel ridge
axis in place spatially over SW KS Sunday and Labor Day, but
models suggest a gradual erosion of heights and thickness during
this time. That said, models show very little if any cooling, with
afternoon temperatures maintaining a persistent theme of 100-103.
Efficient mixing/south winds, and increasing downslope components
(especially Monday) are expected to maintain unseasonably hot
temperatures, with an unseasonably hot, windy dry Labor Day
forecast. Increased wind/wind gust grids to the 90%ile of the NBM
for Labor Day; 850 mb flow of 35-40 mph suggests gusts of that
caliber are likely Monday afternoon.
12z GFS/GEFS and 12z MEX suggest some cooling after Labor Day, but
opted to keep the NBM`s much hotter highs in the far extended.
&&
.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 503 PM CDT Wed Aug 30 2023
Aviation weather will remain quiet with high pressure ridge aloft
prevailing across much of the central portion of the country,
including western Kansas. Some high level smoke from Canada
wildfires made its way down to Kansas, reducing visibility to
around 6 to 8 miles at times, but HRRR Smoke modeling suggests
smoke concentration will continue to wane through this period, so
no impacts on aviation are expected. Winds will increase out of
the south on Thursday to 15 to 18 knots sustained with gusts in
the 25-30 knot range in the afternoon.
&&
.FIRE WEATHER...
Issued at 200 PM CDT Wed Aug 30 2023
Unseasonably hot afternoons, with max temperatures within a few
degrees of 100, are expected Friday through the Labor Day weekend.
This will drive min RH to as low as 15% each afternoon. Combined
with elevated south winds each day, averaging 20-30 mph, the risk
of wildfire spread will increase over the weekend where fuels have
dried sufficiently to support fire spread. Fire headlines may be
necessary, especially western counties. After a wet summer, fuels
are abundant and this potential will be monitored closely over the
weekend.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 61 96 64 100 / 0 0 0 0
GCK 61 94 64 99 / 0 0 0 0
EHA 61 99 64 99 / 0 0 0 0
LBL 59 96 63 100 / 0 0 0 0
HYS 60 95 64 102 / 0 0 0 0
P28 61 94 64 98 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Turner
LONG TERM...Turner
AVIATION...Umscheid
FIRE WEATHER...Turner
Area Forecast Discussion
National Weather Service Goodland KS
521 PM MDT Wed Aug 30 2023
.SHORT TERM...(This evening through Friday Night)
Issued at 241 PM MDT Wed Aug 30 2023
At the start of the short term period, the latest RAP analysis shows
the CWA having a north-northwesterly flow aloft being underneath
a positively tilted ridge between upper air lows in western MT and
eastern TX. Current satellite imagery and surface observations
show mostly sunny skies with dry conditions across the CWA. Going
through the rest of Wednesday, models forecast the CWA continuing
to be underneath the upper air ridge with a shortwave disturbance
making its way through the flow during the overnight hours. At the
surface, dry conditions are expected to continue across the CWA
through the rest of the Wednesday with elevated to near critical
fire weather conditions seen along and west of the CO border. A
surface trough is projected to stick around in eastern CO allowing
for a mostly southerly flow across the CWA. When looking at the
vertically integrated smoke product produced by the HRRR, it shows
smoke from the Canadian wildfires moving into the eastern
portions of the CWA by the evening hours and lasting through the
night. Slightly reduced visibility may be possible with this
smoke, but models are not showing too much of a major concern as
it stays almost as more of a haze. Will continue to monitor this
in case future model runs start a bigger impact. Overnight lows
for tonight are forecasted to be in the upper 50s to lower 60s
range.
For Thursday, forecast guidance shows an upper air ridge building
over the Central Plains through the entire day that is slightly
suppressed as the MT low moving past just north of the ND border in
Canada during the evening hours. Another weak shortwave
disturbance is seen in the flow over the CWA in the evening as
well. At the surface, another day of dry conditions is expected.
Models continue to show a surface trough in eastern CO allowing
for the southerly surface winds to persist across the CWA with
gusts up to around 25 kts east of the CO border. Elevated to near
critical fire weather conditions are expected within the CWA
though lower minimum RH values in the middle teens are seen along
and west of the CO border with slower winds while the quicker
winds are expected east of the CO with minimum RH values above 20
percent. Will continue to monitor this in case conditions worsen
and fire weather highlights are needed. The HRRR shows wildfire
smoke lingering into the morning hours for eastern portions before
clearing by the afternoon. Daytime highs for Thursday look to be
in the middle 90s followed by overnight lows in the lower to
middle 60s.
On Friday, models continue to show an upper air ridge reside over
the CWA though have it moving eastward a bit by the evening hours
giving the CWA a southwesterly flow with an upper air low moving
into northern CA. At the surface, a third day of dry conditions is
expected while critical fire weather conditions look possible
particularly for areas along the CO border. Models show another day
of a surface trough in CO causing southerly winds gusting up to
around 25 kts during the day and exceeding 30 kts in some locations
during the overnight hours. Minimum RH values look to be between the
middle teens and lower 20s. This looks to be the best day in the
short term period for a possible fire weather highlight, so will
monitor this in future forecasts. The warming trend looks to
continue with daytime highs on Friday ranging between the middle 90s
and lower 100s. Lows on Friday night are forecasted to be in the
lower to upper 60s.
.LONG TERM...(Saturday through Wednesday)
Issued at 159 PM MDT Wed Aug 30 2023
Persistent warm and dry conditions will last through the weekend,
leading to potentially critical fire weather conditions. Cooler
temperatures and precipitation next week are possible.
Over the weekend, we will remain under a ridge. Saturday, Sunday,
and potentially Monday, could see near-critical to critical fire
weather conditions. With maximum temperatures reaching near triple
digits east of highway 27, RH values are expected to be near 15% or
lower. RH values on Saturday are currently forecast to drop near 12-
13% in far western Kansas. Sunday will be a little better with
minimum RH values being 1-2% higher. Winds are the questionable
category to support critical fire weather conditions. Southerly
winds at 15-20 kts on Saturday and Sunday, with gusts up to 25 kts
on Sunday, are forecast. Localized fire weather conditions may
become critical, mainly in western Kansas. Confidence for multiple
counties meeting critical fire weather conditions is increasing,
with winds being the limiting factor. The areas with the most
potential to hit critical fire weather conditions are Wallace and
Greeley counties.
Monday morning the ridge will slowly be pushed east by a trough
coming in from the west. The placement and speed of the 250 mb
trough around 12Z Tuesday is the wild card for the period. The
current runs of the GFS, ECMWF, and CMC-NH are showing very
different solutions versus 24 hours ago. The GEFS 12Z has remained
fairly consistent over the past 24 hours, however it has slowed the
timing of the trough. GEFS shows a trough just south of the
U.S./Canada border. These varieties of solutions lessens confidence
on placement, timing, and overall impactfulness of the feature. The
associated surface FROPA is looking more likely to occur in the
evening, if not overnight Monday. This will allow some moisture to
potentially move in with the LLJ and give us a chance of
precipitation. Confidence for precipitation is low as PoPs are only
15-28 across the area after 0Z Tuesday.
Saturday and Sunday, high temperatures will be in the mid 90s to
lower 100s. Monday will slightly cool down with triple digits only
forecast for Graham County. Tuesday`s highs looking to be in the mid
80s and 90s. Wednesday will start warming us up again with most
locations reaching the 90s, as a new ridge will begins working into
the area. Overnight temperatures will follow a similar trend, but to
a lesser extent. Temperatures are expected to remain in the 60s to
low 70s with the potential of northwestern CWA cooling into the
upper 50s Tuesday and Wednesday morning.
&&
.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 517 PM MDT Wed Aug 30 2023
Smoke continues across the central plains as apparent on visible
satellite. Visibility at KMCK has been slowly dropping through the
afternoon and visibility likely to be 5-6SM through tonight. So,
MVFR conditions may be possible. At KGLD, thinking the visibility
will remain above 6SM based on HRRR vertically integrated smoke
and visibility forecasts. Both locations will see low level wind
shear developing this evening and continue through early Thursday
morning with a southwesterly nocturnal low level jet.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...076
LONG TERM...CA
AVIATION...024
Area Forecast Discussion
National Weather Service Morristown TN
1011 PM EDT Wed Aug 30 2023
...New UPDATE...
.UPDATE...
Issued at 1004 PM EDT Wed Aug 30 2023
A quiet night across the local area as tropical storm Idalia
continues to move across the SC coast. Wind gusts have subsided
over the past couple of hours, but a sustained northerly wind
around 5-10 mph should continue for several more hours. This will
work to keep fog formation limited overnight. Temperatures should
be much cooler tonight, generally in the 50`s to lower 60`s. No
updates needed.
&&
.SHORT TERM...
(This evening through Thursday)
Issued at 241 PM EDT Wed Aug 30 2023
Key Messages:
1. A few spotty showers, perhaps an isolated storm, through is
evening along the spine of the Appalachians and down across
southwest NC.
2. Sustained north winds from 5 to 10 mph overnight.
3. Temperatures around 5 degrees below normal tonight and
tomorrow.
Discussion:
Hurricane Idalia is currently tracking through GA and SC with high
clouds spread across most of the east TN Valley. The outer most rain
bands from Idalia our well east of the Appalchians but convergent
flow along the spine of the Appalachians, combined with daytime
heating, has sparked a few spotty showers at the current hour. HRRR
shows isolated showers, and perhaps an isolated storm, continuing
across the east TN mountains and down into southwest NC through this
evening. Then, clouds will clear as Idalia pushes further east and
precip will end. Sustained north winds from 5 to 10 mph are expected
overnight with temperatures around 5 degrees below normal.
Tomorrow will be a beautiful day with plenty of sun, slightly below
normal temperatures and slightly drier air in place. Get outdoors
and enjoy it if you can!
&&
.LONG TERM...
(Thursday night through next Wednesday)
Issued at 241 PM EDT Wed Aug 30 2023
Key Messages:
1. No rain expected the entire period.
2. Below normal temps through Saturday, with near to slightly above
normal temperatures next week.
Discussion:
A large high pressure ridge will be over the Great Lakes region at
the start of the period. A surface high over New England will push a
backdoor cold front across the Carolinas/Georgia on Friday, with an
inverted trough developing across the southern Appalachians and TN
Valley. Some models spit out some light QPF in the SW NC mountains
with this trough, but the vast majority of precip stays well to our
south in central AL/GA near the frontal boundary and warm sector.
Will keep a dry forecast going for Friday, but there will be some
increasing clouds with the trough in southern sections.
The high pressure ridge to our north slowly drifts southward and
sets up over KY/TN on Saturday, with an omega block pattern setting
up into early next week. This will provide dry and mostly sunny
conditions for the area at least through Wednesday. With the
building ridge will come warmer temperatures, rising to a few
degrees above normal for Monday through Wednesday.
&&
.AVIATION...
(00Z TAFS)
Issued at 832 PM EDT Wed Aug 30 2023
VFR expected for the next 24 hours. Northerly winds around 10
knots with higher gusts look to continue at CHA through 06z
tonight and through 15z at TYS. Winds at TRI will stay light, less
than 5 knots from the north.
&&
.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN 63 84 66 83 / 0 0 10 10
Knoxville McGhee Tyson Airport, TN 60 82 63 85 / 10 0 0 10
Oak Ridge, TN 60 82 62 84 / 0 0 0 10
Tri Cities Airport, TN 57 79 58 82 / 10 0 0 0
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
SHORT TERM...Diegan
LONG TERM....DGS
AVIATION...Diegan
...Updated Aviation Forecast Discussion...
.DISCUSSION...
Issued at 323 PM CDT Wed Aug 30 2023
Key Messages:
- Smoke concentrations are beginning to decrease, with some
lingering through Thursday morning,
- Heat returns this weekend, where northeast Nebraska will see
heat indices over 100 degrees.
- Best chance of rain comes Monday into Tuesday.
Today and Tomorrow.
Water vapor imagery over the CONUS this afternoon is dominated by
a mature trough over the Montana/Idaho region while the tropical
system continues to swirl over the southeast. Zooming in locally,
smoke continues to waft through the air, with concentrations
generally on the decrease through next 24 hours. An Air Quality
Alert issued by the state of Nebraska is still in effect through
noon Thursday, with the main story of the short term being highs
in the mid-to-low 80s and some gusty afternoons through the rest
of the work week thanks to a tightening pressure gradient and
increasing low-level winds that we`ll mix into.
Friday through Tuesday
The main concern of the forecast period comes this weekend into
early next week, as another heat wave takes aim on the area. 850
mb temperature anomalies are generally 10-13 degrees Celsius above
normal and are topping the charts in reanalysis data for this time
of the year. Highs across eastern Nebraska and southwest Iowa are
slated to rise to the mid-to-upper 90s, while portions of
northeast Nebraska near the South Dakota border will reach 100
degrees or more. Once again there is a stark difference between
the EPS guidance and the GEFS, with high temperatures this
weekend in Omaha differing by 15 degrees depending on which
guidance you look at. For now, it`s a conservative approach
leaning slightly cooler than halfway between the two. As far as
surface moisture goes, we`ll find ourselves about 10 to 15 degrees
lower dewpoint-wise than we were with the last heat wave, make it
a little more bearable and only a few spots are currently hitting
105 degree heat indices in the forecast. As of right now, Norfolk
is forecast to either tie or break its high temperature records on
Saturday and Sunday.
Fortunately a patter change comes quickly next week as a low-
amplitude trough swings by just to the west, dragging a front and
some chances at moisture late Monday into Tuesday. As of right
now, it doesn`t look like a soaker but it still could serve as a
nice change from our recent dry spell. Highs next week generally
decrease to the upper 80s to low 90s, keeping us not quite as hot
but still several degrees above normal.
&&
.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
Issued at 607 PM CDT Wed Aug 30 2023
Visible satellite imagery and surface observations indicate KOFK
and KLNK on the eastern fringe of higher smoke concentrations with
visibilities of 7SM being reported at both sites. Latest HRRR and
RAP output suggest those higher concentrations will shift to the
west and north of the area overnight with prevailing VFR
conditions forecast at all terminal locations. South-southeast
surface winds could become gusty tonight, and moreso by mid mid-
morning Thursday. Finally, some LLWS is possible in the KOFK
vicinity late tonight into Thursday morning.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...None.
IA...None.
&&
$$
DISCUSSION...Petersen
AVIATION...Mead