Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 09/05/23
Area Forecast Discussion
National Weather Service La Crosse WI
601 PM CDT Mon Sep 4 2023
.DISCUSSION...(This evening through Monday)
Issued at 230 PM CDT Mon Sep 4 2023
Key Messages:
- Humidity joins the near-record temperatures for Tuesday,
pushing heat indices to 95-105 degrees F despite slightly
cooler temperatures. Fire weather concerns diminish with the
increasing humidity.
- Details regarding the storm and rainfall risk for Tuesday
evening/night remain quite uncertain. There is a signal in the
latest guidance that the risk for storms may be focused north
of I-94.
- Aside from lingering showers Wednesday, there is little hope
for additional rainfall through the end of the week. Seasonal
weather settles in for Wednesday through next weekend.
Tuesday: Hot and Humid Weather for One More Day
Early afternoon water vapor imagery shows a blocking pattern
gradually decaying over the central U.S. as what once was a cutoff
low meanders northeastward ahead of a trough ejecting through the
Northern Rockies. This pattern shift allows Gulf moisture to
stream northward tonight and sets the stage for a more humid day
tomorrow. Dewpoints in the lower Missouri River Valley, currently
in the upper 60s to lower 70s, should be commonplace here for the
day on Tuesday. Thus, while the thermal ridge has retreated north
and out of the region, the combination of still anomalous warmth
and humidity will cause heat indices to reach 95-105 degrees
Tuesday afternoon. The fire danger that arose from the lower
humidity values these last few days wanes this evening.
Tuesday Evening: Storm Threat Details
A High Plains surface front slides eastward during the day on
Tuesday ahead of a trough riding the sub-tropical jet. This
feature has been our lone shot of precipitation for this week and
the latest 12Z CAM suite did not make the forecast any easier. As
was alluded to yesterday, the cap strength ahead of this trough
may limit the aerial coverage of the convection. The 12Z NAM,
NAMNest, WRF ARW, and NSSL WRF all came in dry south of the I-94
corridor for Tuesday night into Wednesday--keeping the robust
convection well to the northwest. The 12Z HRRR also showed a
decrease in precipitation coverage compared to its 06Z run. In
addition to the cap strength, the best upper level and lower level
forcing look displaced north of the forecast area. For now, have
left the NBM PoPs alone so trends can be assessed, but should this
trend continue we will need to look at decreasing PoPs.
Storm mode is also complicated by the less than optimal
environmental shear profiles. Complex hodographs exist above 1 km
that will limit updraft longevity, despite ample instability
(1500+ J/kg) aloft to fuel initial updraft growth. Between these
weak shear profiles and a mean mid-tropospheric boundary-parallel
flow (keeping the individual convective elements moving to the
north/northeast), the expectations are that any discrete storms
that do initiate will have just a short window to become severe
before merging and growing upscale into multi-cell complexes.
Wednesday: Lingering Showers and Cooler
The upper wave slows and becomes meridional for the day on
Wednesday as it runs up against the blocking East Coast ridge.
This allows a second shortwave ejecting from the Great Basin to
catch up to its lead counterpart and merge by Thursday morning--
the net result being to keep synoptic cyclonic flow in place
through Wednesday night. Negative theta-e advection takes place
in the lower troposphere through the day on Wednesday, likely
bringing a low stratocumulus cloud deck with it. These clouds
should temper high temperatures during the day, but to what degree
is resulting in a 5-10 degree spread amongst the ensemble
guidance. Most of the ensemble guidance also depicts some shower
activity rotating around the surface low to the east, but a
sounding analysis shows most of the lower tropospheric moisture
restricted in depth and a strong warm nose aloft limiting the risk
of convection, so the coverage of showers (and thunder) is a
source of uncertainty in the forecast. Best odds for showers
through the day will be closer to the low in central Wisconsin.
Thursday - Monday: Seasonal Weather, Minimal Rain Opportunities
Upper ridging ushers the mid-week system further east by Thursday,
with split upper level flow and surface high pressure dominating
the pattern into the weekend. Mostly cloudy skies Thursday morning
should clear through the day as cyclonic flow wanes, with mostly
clear to clear skies into the weekend. Temperatures on Thursday
should stay seasonably cool under the clouds, but rebound back to
near average for Friday and the weekend. The next shortwave on
the horizon drives southeastward into the region on Sunday into
Monday, but at this range it is far too early to determine any
precipitation details.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 601 PM CDT Mon Sep 4 2023
VFR conditions are expected through most, if not all of Tuesday,
with periods of mid/high clouds. Southerly winds will subside with
sunset this evening, although some gusts near/above 20 kts are
possible overnight, especially at KRST. Winds will become gusty
again Tuesday morning at 10-20G25-30 kts.
A cold front will approach late Tuesday afternoon/evening with a
50-70 percent chance for showers/storms. Although low (20-40%)
shower/storm chances are expected by later Tuesday afternoon
(21-22Z), the most likely window resides just beyond this TAF
period, so will not introduce any RA/TSRA into the TAFs for this
update. Winds will trend westerly and eventually northwesterly
Tuesday night and Wednesday behind the front.
&&
.CLIMATE...
Issued at 230 PM CDT Mon Sep 4 2023
Monday, September 4 Record High Forecast
-----------------------------------------------
La Crosse 95 set in 1925 97
Rochester 94 set in 1893 94
Tuesday, September 5 Record High Forecast
-----------------------------------------------
La Crosse 95 set in 1922 95
Rochester 94 set in 1913 92
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...Heat Advisory until 6 PM CDT Tuesday for WIZ032>034-041-042-053-
054.
MN...Heat Advisory until 6 PM CDT Tuesday for MNZ079-088-096.
IA...Heat Advisory until 6 PM CDT Tuesday for IAZ011.
&&
$$
DISCUSSION...Skow
AVIATION...JM
CLIMATE...Skow
AREA FORECAST DISCUSSION
National Weather Service Bismarck ND
1047 PM CDT Mon Sep 4 2023
.UPDATE...
Issued at 1046 PM CDT Mon Sep 4 2023
Will allow the remainder of Severe Thunderstorm Watch 667 to
expire for central North Dakota. A few stronger storms remain
possible, possibly capable of marginally severe hail. Overall
though, the severe weather threat has ended.
UPDATE Issued at 942 PM CDT Mon Sep 4 2023
Opted to drop areas of the thunderstorm watch west of the Missouri
River with this product issuance. Other areas remain in effect as
the bowing line continues northeast, with strong wind gusts to 60
mph observed lagging the main push, sometimes up to an hour.
UPDATE Issued at 532 PM CDT Mon Sep 4 2023
Severe thunderstorm watch has been issued for parts of far
southwest and south central North Dakota, as well as much of the
James River Valley through this evening. The main threat continues
to be very strong thunderstorm winds, with peak gusts ranging from
70 to 90 mph, with the best chance of occurrence from Mobridge,
SD northeast through Jamestown, associated with a line of storms
moving into a more favorable environment and as a potent mid level
low swings east across the Dakotas.
&&
.SHORT TERM...(This Evening through Tuesday)
Issued at 215 PM CDT Mon Sep 4 2023
Current surface analysis places low over Manitoba with a trough
extending southward through the northern plains, while a cold
front stretches to the southwest of the low, just nudging into
extreme northwest North Dakota into eastern Montana. Ahead of the
front, temperatures have warmed mainly into the 80s and lower 90s,
while behind the front wildfire smoke is notably dropping
visibilities, with temperatures in the 50s and 60s. Upper level
analysis places staunch trough with a slightly negative tilt
stretching through central Montana into western Wyoming. A variety
of notable short waves swinging around the trough are sliding up
southwest flow which stretches through our area. A few rain
showers behind the aforementioned cold front are trying to work
their way towards northwest North Dakota, but the start of the
main show that will be affecting us is a line of storms stretching
from far southeast Montana through northeast Wyoming into far
southwest South Dakota.
For late this afternoon into tonight, aforementioned area of
storms to the southwest will continue its approach. Latest timing
of the storms bring them to the far southwest North Dakota border
around 23Z (5 PM MDT), for which most CAMs have been pretty
consistent with through the day. As the storms lift towards our
area, they will encounter an environment with CAPE values of
1000-2000 J/Kg and about 40 to 50 kts of deep layer shear, all
plenty for severe potential and large hail, particularly if we get
a few stray storms developing ahead of the main line. What
continues to catch our eye, though, is the potential for strong
damaging wind gusts. Forecast parameters for wind potential
continue to be on par with what was previously discussed early
this morning with 0-3KM shear values in the 25 to 35 kt range, and
DCAPE values of 1000+ J/kg. So, much of southwest and central
North Dakota are in play for severe weather this evening, but the
corridor of greatest concern continues to be south central North
Dakota into portions of southwest where the greatest severe
parameters are lining up. Therefore, will continue to message
potential for 70 mph gusts with an isolated 80 mph possible.
Severe threat wanes and exits by around 06Z, but showers and tamer
thunderstorms continue though the overnight into Tuesday before
gradually diminishing and departing the area.
As for rainfall amounts, NBM probabilities continue to click up,
with now a 50 to 80 percent chance of seeing an inch of rainfall
tonight through Tuesday over much of southwest and south central
North Dakota, The greatest values are around Bismarck stretching
towards Glen Ullin, Hettinger, and Fort Yates, where, when
looking at potential for 2 inches, a 30 to 50 percent chance
exists.
Now, on to a separate concern, smoke. Behind the advancing cold
front which is now pushing into far northwest North Dakota,
visibility has notably dropped off along with air quality as the
next batch of wildfire smoke makes its way into the area.
Therefore, have brought smoke into the area in line with latest
HRRR near surface smoke guidance. There is still some question as
to how the smoke will interact with the anticipated rainfall, but
earlier this summer we had an event where notable smoke lingered
around while thunderstorms were occurring. Continued having smoke
in the area through Tuesday/Tuesday night.
.LONG TERM...(Wednesday through Monday)
Issued at 215 PM CDT Mon Sep 4 2023
Near to below average temperatures are expected through this time
period. Occasional shower/storm chances develop over the area from
time to time, but based on latest parameters concern for severe is
low.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday Afternoon)
Issued at 700 PM CDT Mon Sep 4 2023
Thunderstorms will move into western North Dakota late this
afternoon, spreading east this evening. A few of these storms may
become severe with large hail and strong wind gusts. Localized
MVFR to IFR visibilities will be possible under any of the heavier
showers or storms. IFR to MVFR ceilings will also move into the
southwest and south central late in the period as a steadier rain settles
in.
In addition, areas of smoke will move south tonight, impacting all
terminals through Tuesday. This may drop visibility to MVFR and
IFR levels at times.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE...NH
SHORT TERM...JJS
LONG TERM...JJS
AVIATION...NH
Area Forecast Discussion
National Weather Service Dodge City KS
641 PM CDT Mon Sep 4 2023
...Updated Aviation Section...
.SHORT TERM...(This evening through Tuesday night)
Issued at 110 PM CDT Mon Sep 4 2023
Water vapor satellite imagery and RAP upper air analysis at
midday shows longwave troughing over the western CONUS, with an
embedded shortwave trough over western WY and adjacent areas, and
longwave ridging over the easter CONUS. At the surface, broad low
pressure ahead of the upper level trough is spread out from the
northern plains/southern Canada through the central plains, which
is supporting gusty southerly/south-southwesterly winds across
southwest KS. These downsloping winds along with fully clear skies
have already resulted in temperatures rising into the low/mid
90s, and will peak in the low 100s later this afternoon. The good
news is as the aforementioned upper level shortwave trough pushes
east during the evening/overnight period, it will send a dry cold
front through our area during the 06-09Z Tuesday time frame,
bringing a welcomed break to the heat. Northerly winds behind this
boundary will cause temperatures to drop into the low to mid 60s
for most areas early Tuesday, with only the far southeast zones
holding in the upper 60s/low 70s given shorter residence time
within cold advection.
Daytime Tuesday, boundary layer mixing will help maintain strong
north/north-northwest winds across southwest KS for much of the
morning, however building surface high pressure will cause them
to weaken through the afternoon. Regardless, temperatures will
still be noticeably cooler than Monday, as afternoon highs only
reach the upper 80s to low 90s. Tuesday night, the surface high
pressure center will move east over the northern plains, and winds
will trend northeasterly across our area in response with lows
dropping into the 50s to low 60s.
.LONG TERM...(Wednesday through Monday)
Issued at 218 PM CDT Mon Sep 4 2023
Key Messages: Triple digit temperatures return to much of the area
Thursday afternoon, however a cooling trend will follow and
persist through the end of the period. Precipitation chances
increase appreciably early next week.
Medium range ensembles are in agreement at the beginning of the
long term period suggesting a ~594dm upper level ridge will be in
place over the southern plains 12Z Wednesday, with southwest KS
residing on its northeast periphery. Surface high pressure over
the central plains will be in the weakening phase as upper level
shortwave troughs traversing the Intermountain West continue east,
fostering renewed lee cyclogenesis. Winds will trend from
northerly to easterly then finally southeasterly through the day
Wednesday in response, which will only support afternoon highs in
the upper 80s/near 90.
Unfortunately, strong subsidence under the upper level ridge will
foster increasing 850-mb temperatures over southwest KS on
Thursday, which will translate to afternoon highs returning to
the upper 90s/near 100. Thankfully, this may be the last vestige
of true summer heat as ensembles indicate the ridge will slowly
retrograde Friday through the weekend, progressively weakening its
influence over our area and allowing stronger 500-mb flow across
the central Rockies. This will result in a gradual cooling trend
as afternoon highs decrease by 1-3 degrees each day through
Sunday. Precipitation chances will also return to the central
plains as stronger westerly flow permits more opportunities for
upper level shortwaves to bring much needed rainfall. In fact,
nearly all of the GEFS and EPS members show widespread
precipitation returning either Sunday or Monday and lasting well
into the week, which appear to be the first signs of fall.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 638 PM CDT Mon Sep 4 2023
Fairly strong south to southwest winds at the onset of this TAF
period will continue through sunset before tapering off to 11 to
14 knot range. A strong low level jet will develop, yielding
marginal LLWS conditions at DDC and HYS ahead of an approaching
cold front. The cold front is forecast to push south overnight,
in the 07-09Z time frame. There will be an hour or two of strong
north-northwest winds in the 20 to 25 knot range, but winds will
quickly pull back to 10 to 12 knots thereafter, until increasing
again a few hours after sunrise. Dry air will remain in place,
including after the frontal passage, so VFR flight category will
continue all terminals through this TAF period.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 67 91 57 88 / 0 0 0 0
GCK 62 87 54 87 / 0 0 0 0
EHA 61 88 56 90 / 0 0 0 0
LBL 63 91 57 89 / 10 0 0 0
HYS 67 89 55 85 / 10 0 0 0
P28 73 95 63 89 / 10 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning until 9 PM CDT this evening for KSZ084>089.
&&
$$
SHORT TERM...Springer
LONG TERM...Springer
AVIATION...Umscheid
AREA FORECAST DISCUSSION
National Weather Service Kansas City/Pleasant Hill MO
606 PM CDT Mon Sep 4 2023
.Discussion...
Issued at 402 PM CDT MON SEP 4 2023
Key messages:
- Unseasonably hot temperatures today and tomorrow.
- Cold front moves through tomorrow afternoon/evening. Isolated
storms may be possible, especially toward central Missouri.
- Cooler temperatures expected for Wednesday through the weekend
(generally near seasonal normals).
Discussion:
Unseasonably hot across the region this afternoon with
temperatures in the mid to 90s as of 3 PM with head indices in the
upper 90s to near 100 degrees. An approaching trough moving into
the Northern Plains along with a mid level low over eastern
Oklahoma has increased low level southerly flow, with gusts up to
25 mph this afternoon. Showers and storms associated with the mid
level low over eastern OK have developed over southwestern
Missouri this afternoon, and it is possible that a few may reach
as far north as Bates to Cooper County a bit later this afternoon.
A strong nocturnal low level jet will keep temperatures warm and
winds breezy through the overnight period, with lows in the mid
70s for most locations. Isolated to scattered elevated showers and
perhaps a rumble of thunder or two will likely develop over
eastern Kansas by early Tuesday morning and advance eastward into
western and eventually central Missouri by mid to late Tuesday
morning, but dry low level air will likely make it difficult for
much rain to reach the surface. The aforementioned trough moving
across the Northern Plain into the Upper Midwest will send a cold
front toward the region from the west tomorrow afternoon, with
strong southerly winds, relatively elevated surface dew points,
and hot temperatures out ahead of the front. Temperatures should
rise into the mid to even upper 90s with heat indices reaching the
100 to even 105 degree range for a couple hours tomorrow afternoon
before the front arrives. As of now, the front looks to arrive in
the KC metro by around mid afternoon, with winds turning westerly
and drier air coming behind the front. Storms may be possible
along the front, especially east of the KC metro (the HRRR does
not convect for our region, but the NAM Nest does). If any
convection does manage to initiate, a strong storm or two cannot
be ruled out given ample instability.
Cooler and drier air comes behind the front for Wednesday into the
end of the week as the region will be sandwiched between a stout
mid level high over New Mexico to the southwest and troughing to
the east. High temperatures look to be generally in the mid 80s
for most of the region, with cooler temperatures over northeastern
Missouri and warmer temperatures to the southwest of the KC
metro. Generally dry conditions are forecast to persist outside of
some slight chance PoPs Thursday night into Friday morning and
again on Sunday morning.
&&
.Aviation...(For the 00Z TAFS through 00Z Tuesday Evening)
Issued at 606 PM CDT MON SEP 4 2023
Southerly wind should continue, especially with the surging outflow
moving in from the south. Expect the wind to persist overnight, with
perhaps some gradual decrease. FROPA begins tomorrow in the mid to
late afternoon, so have indicated a wind shift as that boundary
moves in.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
Discussion...BMW
Aviation...Leighton
Area Forecast Discussion
National Weather Service Austin/San Antonio TX
556 PM CDT Mon Sep 4 2023
...New AVIATION...
.SHORT TERM...
(Tonight through Tuesday night)
Issued at 150 PM CDT Mon Sep 4 2023
RAP analysis depicts the upper low in E OK, with model guidance
showing it opening up this afternoon as it begins the process of
getting picked up by the trough to our northwest. It should
gradually exit to the northeast through tonight, with subtropical
ridging building over the southern CONUS and northern Mexico through
the rest of the short term.
Onshore low level flow over the middle and upper TX coast is leading
to some shower and storm activity today, but this should only impact
our far eastern counties with minimal, isolated rainfall amounts. As
the sea breeze pushes inland this evening, the NAM and it`s nest
continue to point towards a low potential for an isolated storm to
develop along it in the greater San Antonio area. Most other
guidance doesn`t buy into this, though the FV3 does have an evening
storm in the Atascosa County area, and even the HRRR is beginning to
get into the game with a few evening cells just east of I-35 in the
Coastal Plains. A 10% chance has been added to the forecast from 7-
10pm for portions of the region to cover this possibility, and may
need to be pushed up to 20% in future updates.
Otherwise, temperatures and heat indices should remain just below
heat advisory thresholds for the most part, so will let the SPS ride
today. Heat Indices may briefly exceed 108 in mainly Lavaca/DeWitt
Counties, but with some more cloud cover and rain chances and a
looooong summer of heat, will stick with the SPS there as well.
Similar conditions are expected tomorrow, with again a low chance
for a shower/storm over the US-77 corridor. At this time, do not
anticipate a Heat Advisory for tomorrow but cannot completely rule
it out.
&&
.LONG TERM...
(Wednesday through Monday)
Issued at 150 PM CDT Mon Sep 4 2023
The subtropical high continues to build across west Texas on
Wednesday while an upper level trough axis pushes across the coastal
plains. The combination of daytime heating along with the trough
axis could produce isolated shower and thunderstorm activity across
the coastal plains in the afternoon period. Otherwise, expect hot
weather conditions with highs in the mid 90s and up to 104 degrees.
A few areas are likely to reach heat advisory criteria for a short
period of time, but nothing widespread this far out. We will closely
monitor this situation.
The warming trend continues on Thursday into Friday as the
subtropical high slightly moves to the east. This scenario brings
drier and hotter weather conditions are the local area. Thursday`s
high range from the upper 90s across the Hill Country and 103 to 105
along the I-35 corridor including the Austin metro area and the
coastal plains. Similar conditions are expected for Friday with highs
reaching up to 107 degrees over a few spots. Heat headlines are
likely issued for Thursday and Friday during the middle of the week
if weather guidance remain suggesting this hot weather period.
The subtropical high weakens a little bit for next Saturday as an
upper level shortwave axis pushes across east Texas and another
upper level shortwave moves across east Texas on Sunday afternoon.
With plenty of hot weather conditions in addition to some
instability in place, expect isolated shower or thunderstorm
activity across the Hill Country, I-35 and interstate 35 mainly in
the afternoons through the early evening hours.
Overall dry and hot weather conditions are helping near critical
fire weather conditions across the local area for the next five to
seven days. More details below in the Fire Weather section.
&&
.AVIATION...
(00Z TAFS)
Issued at 556 PM CDT Mon Sep 4 2023
Scattered mid-level clouds continue over the eastern half of South-
Central Texas for the start of the period. The seabreeze is
beginning to move inland which will bring some breezy southeast wind
this evening with gusts up to near 23 knots possible through
midnight. A few storms may develop in the Coastal Plains through
03Z, but look to remain well east of I-35 sites. A period of MVFR
ceilings returns to I-35 sites around 08-09Z, possibly lingering as
long as 15Z. VFR conditions will remain through the period at DRT.
&&
.FIRE WEATHER...
Issued at 150 PM CDT Mon Sep 4 2023
Some slightly higher moisture is sticking around today compared to
the past few days. Portions of the area, mainly in the Hill Country
and southern Edwards Plateau, will see minimum humidity between 20
to 30 percent this afternoon. Even with this small uptick in
moisture, dry to critically dry fuels and southeasterly wind around
10 mph will continue to bring elevated to near critical fire weather
conditions through this evening. A Fire Danger Statement remains
effect through 9 PM this evening over these areas. Slightly more
moisture is seen tomorrow, especially for the western Hill Country
and southern Edwards Plateau. However, winds will be 1-3 mph
stronger tomorrow afternoon, and another Fire Danger Statement may
be needed for portions of the area. Will let the midnight shift
assess forecast trends given the borderline weather situation.
Low relative humidity values are forecast to range from 20 to 30
percent on Thursday across most areas and down to the teens on Friday
across the Hill Country and southern Edwards Plateau. Wind speeds are
likely to range from 7 to 12 mph mainly in the afternoons and early
evening hours. With that said, Fire Danger Statements will be likely
issued in the upcoming days as most of the local area`s fuel dryness
levels range from dry to critically dry.
&&
.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry 78 103 77 103 / 0 10 0 10
Austin Bergstrom Intl Airport 78 102 76 102 / 0 10 10 10
New Braunfels Muni Airport 78 103 77 103 / 10 10 10 10
Burnet Muni Airport 77 101 76 101 / 0 0 0 0
Del Rio Intl Airport 80 104 80 102 / 0 0 0 0
Georgetown Muni Airport 78 102 76 102 / 0 0 0 10
Hondo Muni Airport 75 101 75 100 / 10 0 0 10
San Marcos Muni Airport 77 102 74 102 / 10 10 0 10
La Grange - Fayette Regional 79 99 77 100 / 10 20 0 20
San Antonio Intl Airport 78 101 78 101 / 10 0 10 10
Stinson Muni Airport 79 102 78 102 / 10 0 0 10
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Short-Term...KCW
Long-Term...17
Aviation...27
Area Forecast Discussion
National Weather Service Goodland KS
1004 PM MDT Mon Sep 4 2023
.UPDATE...
Issued at 625 PM MDT Mon Sep 4 2023
The Red Flag Warning has been extended due to the incoming wind
shift to the NW and winds gusting 45 to 55 mph, some blowing dust
may accompany these winds. There is also potential for dry
lightning to accompany any developing storms along and north of
Interstate 70 which may spark a fire.
UPDATE Issued at 522 PM MDT Mon Sep 4 2023
Recent and consistent runs of the HRRR and NAMNEST suggest a
narrow corridor of 40+ knot winds along the leading edge of the
cold front; also added in patchy blowing dust into the forecast as
well along the leading edge of the front. Office dust parameters
aren`t overly optimistic on organized blowing dust occurring but
given this recent dry, hot and breezy pattern there should have
been enough drying of top soils to support some blowing dust,
especially near open and recently harvested fields.
&&
.SHORT TERM...(This evening through Thursday night)
Issued at 210 PM MDT Mon Sep 4 2023
Tonight...a cold front will move through the area, producing north
to northwest winds gusting up to 35 mph. A few locations may see a
brief period of blowing dust as the front moves through. Isolated to
scattered thunderstorms will be possible through about midnight or
so, mainly along and north of Interstate 70 as the front moves
through, interacting with just enough moisture in the 850-500mb
layer. With a lack of much rainfall, dry lightning will be a
concern. Any lightning caused fires along the front may be
difficult to control as the gusty north to northwest winds blow
through the night. Low temperatures are forecast to be in the
lower 50s to middle 60s.
Tuesday-Tuesday night...it will be windy with north to northwest
winds gusting up to 40 mph, steadily decreasing overnight. High
temperatures will be cooler, ranging from the upper 70s to upper
80s. These values are in line with the GFS 850mb temperatures and a
blend of the better performing high temperature guidance from the
past 7 to 15 days. Low temperatures cool into the upper 40s to
middle 50s as a 1020mb surface high moves overhead. No precipitation
is expected.
Wednesday-Wednesday night...the surface high that is forecast to be
over the area in the morning is expected to move east with low
pressure deepening along the Colorado front range. This will support
an increasing pressure gradient and breezy to windy southerly winds
across far eastern Colorado. High temperatures are forecast to be in
the middle 80s, a compromise between NAM/GFS 850mb temperatures and
the better performing high temperature guidance from the past 7 to
15 days. Low temperatures are forecast to be in the lower to upper
50s. No precipitation is expected.
Thursday-Thursday night...broad upper level ridging centered over
the southwest part of the country is forecast. High temperatures
rise back into the lower to middle 90s with low temperatures in the
lower 50s to lower 60s.
.LONG TERM...(Friday through Monday)
Issued at 210 PM MDT Mon Sep 4 2023
Friday...broad upper level ridging, centered over southwest New
Mexico is forecast by the GFS/ECMWF/GEM/GEFS models with 850mb
temperatures in the 22C to 29C range. These values support the NBM
forecast highs in the middle 80s to lower 90s. Low temperatures are
forecast to be in the middle 50s to lower 60s. A weather system
moves across the area during the night, supporting a slight chance
for showers and thunderstorms for most of the area.
Saturday...very little change in the 500mb pattern and 850mb
temperatures so nearly a carbon copy of temperatures expected to
Friday. Another weather system moves through the area from the
northwest during the afternoon and overnight hours, supporting
slight chance and chance pops for showers and thunderstorms.
Sunday...the upper level ridge center is forecast to slide further
south/southwest with a trough to our northeast, putting the area
under northwest flow aloft. We`ll have continued chances for showers
and thunderstorms as weather systems move through the flow with
sufficient moisture for rainfall. GFS/ECMWF/GEM 850mb temperatures
are cooler compared to the prior few days and would support high
temperatures in the lower to middle 80s. I`ve lowered the NBM high
temperatures a few degrees to be more aligned with the 850mb
temperatures and cooler MEX guidance. Low temperatures are forecast
to be in the lower to upper 50s.
Monday...not much change at 500mb with continued chances for showers
and thunderstorms as weather systems move through northwest flow
aloft. High temperatures cool to below normal levels in the lower
70s to lower 80s.
&&
.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 1000 PM MDT Mon Sep 4 2023
Cold front has moved through each terminal and winds are forecast
to remain breezy gusting 25-30 knots, however with VFR
conditions; LLWS will be over concern through the night at each
terminal post frontal. Breezy to gusty winds up to 30-35 knots
from the NNW. Winds will will then relax after sunset Tuesday from
the north around 11 knots.
&&
.CLIMATE...
Issued at 1030 AM MDT Mon Sep 4 2023
Record/near record high temperatures are possible at the following
locations today September 4:
Goodland.....100 degrees set back in 1946 and previous years
McCook.......102 degrees set back in 2013 and previous years
Burlington....99 degrees set back in 1960
Tribune......103 degrees set back in 1899
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...Trigg
SHORT TERM...99
LONG TERM...99
AVIATION...Trigg
CLIMATE...99
Area Forecast Discussion
National Weather Service Lake Charles LA
949 PM CDT Mon Sep 4 2023
...New UPDATE...
.UPDATE...
Issued at 933 PM CDT Mon Sep 4 2023
All of the inherited grids are on track, thus no updates were
necessary. There are a few very light showers in the area, however
this too will taper out for the night pretty soon.
&&
.SHORT TERM...
(Tonight through Wednesday night)
Issued at 250 PM CDT Mon Sep 4 2023
Latest RAP analysis indicates trof axis of the upper level low,
now a shortwave trof, is centered over the region. Widespread
ascent has been noted as showers and thunderstorms spread into
south-central and central Louisiana. Further storms are also
developing along an outflow boundary collision spanning from
Alexandria towards Lake Charles. So far, storms have brought much
needed rain to many portions of the area, particularly where
wildfires have been ongoing.
Through the evening, convection driven both by upper weakness and
diurnal processes will continue over the area, coming to an end
shortly after sundown.
Although the trof exits to the northeast overnight, weakness left
in its wake should allow for another round of showers and
thunderstorms tomorrow. Some guidance is also hinting at an
inverted trof crossing the region tomorrow morning, but confidence
in this is feature being present is low. If it does develop along
the western periphery of surface high over the southeastern US,
rain chances would be further enhanced.
By Wednesday morning, another high pressure ridge starts to nose
in over the region. Rising heights aloft cutting rain chances
short and allowing temperatures to start increasing. High
temperatures which were near-seasonable Monday will begin jumping
by several degrees Tuesday before landing into the mid to upper
90s area- wide Wednesday. Those in inland areas may see isolated
instances of 100F Wednesday.
Forecast heat indices tomorrow are roughly 100 to 106 F in
southwest Louisiana, and 103 to 108 F in southwest Texas.
Currently there are no Heat Advisories for southeast Texas or
southwest Louisiana. If confidence increases in the need for an
Advisory, one may come in later updates.
11/Calhoun
&&
.LONG TERM...
(Thursday through next Sunday)
Issued at 250 PM CDT Mon Sep 4 2023
A mid to upper level ridge centered west of our region coupled with
a mid to upper level trough over the Central and Southeast U.S. will
prevail Thursday and Friday. This will place our region in a
generally dry north to northwest flow aloft. Thus, expect more
subsidence aloft, diminishing precipitation chances, and increasing
temperatures once again over the area. For Thursday and Friday,
expect afternoon highs near 100 to mid 100s along and north of I-10,
mid to upper 90s elsewhere. Lows in the mid to upper 70s.
Saturday through Monday, the longwave trough expected to deepen over
the Eastern half of the U.S. allowing for a front to move through
during the day Saturday. Expect isolated to scattered showers and
thunderstorms Saturday afternoon with the frontal passage,
diminishing thereafter. The front is expected to bring drier air to
the region, lower relative humidity values, and increasing fire
weather concerns Sunday and Monday. Afternoon highs in the mid to
upper 90s, except nearing 100 across inland Southeast Texas.
Overnight lows in the mid to upper 60s north of I-10, near 70 to mid
70s further south.
08/DML
&&
.AVIATION...
(00Z TAFS)
Issued at 720 PM CDT Mon Sep 4 2023
No significant changes to previous TAF thinking. VFR conditions
should continue to prevail through the period outside of during
potential convection...main exception to this rule appears to be
at KAEX as guidance indicates the potential for some temporary
MVFR ceilings and/or visibilities around sunrise Tuesday. Latest
CAM guidance indicates some shower activity developing around the
srn terminals prior to sunrise and moving nwd, then expanding in
coverage through the remainder of the morning and into the
afternoon...for now, capped precip mentions at PROB30.
25
&&
.MARINE...
Issued at 250 PM CDT Mon Sep 4 2023
An upper level low pressure system is set to exit to the northeast
today. Weakness aloft left in its wake should allow the
development of showers and thunderstorms over coastal waters
overnight tonight into tomorrow. Rain chances swiftly diminish
Wednesday through the remainder of the week as upper level high
pressure over the central US returns. Surface level high pressure
will also develop over the northeastern Gulf of Mexico and remain
there for much of the coming week resulting in light onshore flow
and low seas.
11
&&
.FIRE WEATHER...
Issued at 250 PM CDT Mon Sep 4 2023
An upper level low is exiting the region today and tonight which
has resulted in scattered to numerous showers and thunderstorms.
They`ve brought with them a wide corridor of wetting rain,
lightning and gusty winds. Convection will diminish after sundown,
with light southerly winds to follow thereafter. Some patchy
areas of fog will be possible in areas where there is much
rainfall today. Tomorrow, weakness aloft could garner another day
of scattered showers and thunderstorms. High pressure builds in
Wednesday and beyond, decreasing rain chances and increasing
temperatures again.
Even with some beneficial rains, fuels remain critically dry. Burn
bans as well as Fire Danger Statements remain in place across
southeast Texas and all of Louisiana.
11
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 73 95 73 99 / 30 50 10 20
LCH 77 92 76 94 / 20 50 10 30
LFT 78 94 76 98 / 30 50 10 20
BPT 78 95 77 98 / 20 60 10 30
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...None.
TX...None.
GM...None.
&&
$$
SHORT TERM...11
LONG TERM....08
AVIATION...25
Area Forecast Discussion
National Weather Service Memphis TN
1053 PM CDT Mon Sep 4 2023
...New UPDATE...
.UPDATE...
Issued at 1050 PM CDT Mon Sep 4 2023
Still monitoring weak convection over west Tennessee as it fires
up behind an eastward propagating outflow boundary at this hour.
These storms will last another hour or so before tapering off into
light showers as shortwave ridging builds in behind the exiting
shortwave trough. Consistent with radar trends and latest hi-res
models, went ahead and made several adjustments to POPs in both
the short term and through tomorrow. POPs were trimmed back
through the overnight period and through late tomorrow morning as
well. The next batch of showers and storms will be associated with
the main trough axis lifting through the region tomorrow
afternoon.
AC3
&&
.SYNOPSIS...
Issued at 303 PM CDT Mon Sep 4 2023
Warm and humid conditions will prevail across the Midsouth through
midweek, along with continued chances of thunderstorms. An upper
level low pressure system will slowly lift from western Arkansas
into southern Missouri tonight. Thunderstorms will continue in
advance of this upper low. A few of these thunderstorms could
approach severe limits along and west of the Mississippi River
tonight. Large hail and damaging winds will be primary severe
weather threats. A few storms will likely reform over northeast
Arkansas, the Missouri bootheel and northwest Tennessee Tuesday
morning, with limited severe weather chances.
&&
.DISCUSSION...
(This evening through next Sunday)
Issued at 303 PM CDT Mon Sep 4 2023
The forecast starts with early August-like temperatures and
humidity over the Midsouth. Midafternoon GOES water vapor imagery
shows a dual-lobe upper low to our west, aiding in the development
of thunderstorms across much of AR, LA and southern MO. The main
upper low was moving into southwest MO, while a secondary lobe of
energy was evident over northern LA. The northern lobe will
continue northeast toward St. Louis overnight, while the southern
lobe tracks across AR while gradually weakening. The primary
concern for the Midsouth will be late afternoon and evening
thunderstorms, embedded in the midlevel dry slot and low level
instability axis southeast of the northern lobe. KLZK radar showed
storms well underway across AR, upstream from a plume of mixed-
layer CAPE in excess of 3000 J/kg over eastern AR. Coincident
with instability axis are modest midlevel lapse rates below 6 C/kg.
Effective bulk shear around 30kt will likely lend organization
and persistence potential to storms into the midevening hours,
before the boundary layer begins to stabilize. 18Z HRRR soundings
depict downdraft CAPE near 1200 J/kg before 00Z, indicative of a
damaging wind threat. PWAT around 2 inches will support heavy
rainfall.
Storm may redevelop over northeast AR toward sunrise, aided by
approaching weakening southern lobe of the upper low. This
southern lobe / midlevel trough will lift into the lower Ohio
River Valley by midday, leaving weak ridging aloft and limited
severe storms chances over the Midsouth Tuesday afternoon.
The midweek pattern change to northwest flow aloft remains on
track, as the southern plains upper ridge center retrogrades to
southern NM. A weak cold front appear set to pass through the
Midsouth Wednesday night, serving as a focus for thunderstorms.
Thursday`s dewpoints will get knocked down to the upper 60s over
most of the Midsouth.
As we head into the weekend, northwest flow aloft will strengthen,
with another round of storms likely Friday. At this early time, it
appears the bulk of the storms remain to our west and south,
tracking over the southwest half of AR into central and southern
MS. It`s too early to be confident about storm tracks though.
What does appear likely: it`ll feel more like September next
weekend, with highs in 80s, and moderate humidity.
PWB
&&
.AVIATION...
(00Z TAFS)
Issued at 613 PM CDT Mon Sep 4 2023
Showers and thunderstorms are moving through eastern Arkansas and
the Missouri bootheel at this time. 18Z HRRR shows another round
of thunderstorms late tonight which may move through the KMEM and
KJBR area. Scattered thunderstorms are possible over the KMKL area
overnight. VFR conditions are expected for much of the forecast
period. Winds will be mainly from the south at 5 to 10 knots for
much of the forecast period.
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...None.
MO...None.
MS...None.
TN...None.
&&
$$
PUBLIC FORECAST...AC3
AVIATION...ARS
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
1100 PM CDT Mon Sep 4 2023
.UPDATE...
Issued at 1055 PM CDT Mon Sep 4 2023
...925 PM Evening Update for Tuesday`s thunderstorm potential. The
00Z HRRR has widespread convection developing across the region,
while the NamNest is dry. Forecast soundings an uncapped environment
for the NamNest, so not exactly sure why convection doesn`t form. One
idea is that it depends on how that upper level shortwave trough
rotates across the region. Storms will fire right ahead of the
positive vorticity advection, but it`s tough to say exactly where
that will be. If forced to choose, would probably lean more towards
the 00Z HRRR solution than the 00Z NamNest with storms developing in
the warm sector during the afternoon and evening. Currently the best
chance for this is still north and east of I-94, but if things
develop sooner than folks south and west could see better chances for
some much-needed rain.
&&
.DISCUSSION...(This evening through Monday)
Issued at 317 PM CDT Mon Sep 4 2023
KEY MESSAGES:
- Another night with little to no relief from the heat, but cooler
air arrives Tuesday night/Wednesday.
- Slight risk for severe storms across much of the area Tuesday
afternoon ahead of the cold front.
- Wildfire smoke and air quality concerns return behind the frontal
passage for portions of western Minnesota.
A look at current temperatures shows most locations in the mid to
upper 90s with a few locations AOA 100F in W MN. The combination of
gusty winds and low RH has led to near-critical fire weather
conditions across the entire CWA today. Please exercise caution if
you`re planning a campfire or cookout today. The gusty SSW winds
taper off after sunset, but ramp back up on Tuesday ahead of the
cold front. The heat advisory will remain in effect for the Twin
Cities metro until Tuesday afternoon due to the prolonged impacts of
hot daytime temperatures and little to no recovery period due to
warm overnight temperatures. Most locations will cool into the mid
to upper 70s tonight, which is warmer than our average high for this
time of year, but there is relief on the horizon.
On Tuesday, temperatures warm back into the 90s for areas along and
east of a line from St. Cloud to Mankato. Temperatures across W MN
will be limited to the mid to upper 80s thanks to the FROPA. Strong
southwesterly flow will help bring in some Gulf of Mexico moisture.
The enhanced moisture will help keep temperatures a bit lower as
some cloud cover is expected, but also provide a plume of better
instability across the eastern half of the CWA. Ensemble guidance
supports 1500-2500 J/Kg of MLCAPE building along and ahead of the
shortwave disturbance. Forecast soundings show impressive lapse
rates of 8.0C/Km + and 25 to 35 kts of bulk shear across southern,
central Minnesota, and western Wisconsin. 12Z HREF has convective
initiation over NE/EC MN and NW/WC WI and quickly growing upscale
into an MCS passing across northern WI in the late evening hours.
SPC SWO day 2 maintained the Slight risk across central/eastern MN
and NW WI. Large hail and damaging winds will be the primary risks.
Rain amounts will be rather light. Most locations only see a few
0.01" up to a 0.10" that will do little but wet the dry, dusty
ground. There is potential for some locally heavier amounts up to a
0.50" for locations that could see multiple storms/showers track
through.
Cooler, more seasonable temperatures arrive on Wednesday along with
Canadian wildfire smoke. Highs in the upper 60s to lower 70s with
gusty NW winds will reassure us that we do in fact live in the Upper
Midwest. Surface high pressure is expected to dominate the forecast
into the weekend. Northwesterly to zonal flow aloft will keep us
more in line with the Fall-like conditions that we`d expect in
September. Precip chances return to the forecast on Sunday as a weak
shortwave moves through the flow aloft. There is significant
ensemble member spread with respect to timing and strength of the
wave so no reason to differ from the NMB PoPs.
&&
.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 1055 PM CDT Mon Sep 4 2023
VFR conditions continue overnight and Tuesday scattered
showers/thunderstorms will develop, mainly during the afternoon and
evening. Continues with a Prob30 for -shra and most locations, but
did include thunder at KRNH and KAXN where there is a better chance
of storms.
KMSP...
Primarily VFR conditions. Winds will decrease overnight, and pick up
from the south/southwest on Tuesday with gusts near 20 kts possible
again. Scattered showers and thunderstorms will develop Tuesday
afternoon, but for now only have a Prob30 of -SHRA since the chance
for thunder is too low to mention in the TAFs. Looking ahead, winds
will become northwest Tuesday night.
/OUTLOOK FOR KMSP/
Wed...Mainly VFR. Chc MVFR/TSRA/SHRA early. Wind NW 15G25 kts.
Thu...VFR. Wind N 10-15 kts.
Fri...VFR. Wind N 5-10 kts.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...Heat Advisory until 5 PM CDT Tuesday for Anoka-Carver-Dakota-
Goodhue-Hennepin-Ramsey-Scott-Washington.
WI...Heat Advisory until 5 PM CDT Tuesday for Pepin-Pierce.
&&
$$
UPDATE...JRB
DISCUSSION...BPH
AVIATION...JRB
...Updated Aviation Forecast Discussion...
.DISCUSSION...
Issued at 254 PM CDT Mon Sep 4 2023
Key Messages:
- Low chances (20%) for weak thunderstorms and rain showers this
evening and tomorrow morning. Severe storms seem unlikely.
- Tuesday and Wednesday will both be breezy. The stronger winds
are expected Tuesday behind the cold front where peak wind
gusts will be near 30 mph.
Today and Tomorrow:
As of 2 PM, most ground stations have reached at least 90
degrees. Temperatures this afternoon will peak in the mid to upper
90s across the area. This will the hottest day for the next week.
Portions of area (south and east of a line from David City to
West Point to Onawa, IA) are forecast to reach 90 degrees
tomorrow. Tomorrow may be the last widespread 90 degree day of the
year. Climatology would say no, as the average last 90 degree day
for Omaha is September 13. For the past 8 years, Omaha has had a
90 degree day near the end of September or in the beginning of
October.
The skies are cloud free except for some development in southeast
Nebraska and southwest Iowa. This development is associated with
the remnants of a tropical system that has migrated north. On the
south side of that closed low, it has initiated a line of
thunderstorms in southern Missouri. On the north side of the low,
it has led to weak showers which may not even be reaching the
surface as the low levels are very dry. As the mid-level low
continues to drift to the north and east, it may develop some
weak, spotty showers in southeast Nebraska or southwest Iowa.
Little if any significant accumulation is expected from this
chance of precipitation this afternoon and evening.
Winds have increased in speed this afternoon with sustained winds
ranging between 15 to 20 mph with gusts up to 30 mph. Winds will
weaken somewhat in the evening with gusts dropping below 20 mph.
Winds will maintain some strength ahead of a cold front that will
begin to move into the forecast area very late this evening. The
front will slowly move through the forecast area not clearing our
Iowa counties until tomorrow afternoon. Weak thunderstorms or
rain showers along this front will be possible. In addition to the
frontal passage, the low level jet will increase to about 40 to
50 knots late this evening and maintain it`s strength until the
frontal passage. If precipitation does develop, the LLJ would work
to increase the coverage of that line of precipitation. The only
CAMs showing precipitation are the HRRR and FV3. There is a lot of
low level dry air to overcome. Severe storms are unlikely.
Wednesday through Sunday:
The remainder of the work week is expected to remain dry with the
best chances for precipitation over the weekend. Temperatures will
drop into the 70s and 80s Wednesday with the passage of the cold
front. Winds will be breezy with gusts up to 30 mph Wednesday
morning and afternoon. On Thursday, a weak mid-level ridge
combined with return flow in the low levels will allow
temperatures to jump into the mid to upper 80s across the area.
There are some low end chances for precipitation these two days
but we`ll need to wait for the event to near to better diagnose
it. A frontal passage is expected over the weekend which will drop
high temps back into the 70s. That frontal passage will bring the
best chance for precipitation in the forecast period.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 611 PM CDT Mon Sep 4 2023
VFR conditions through the period with winds the primary concern.
Winds at TAF issuance from the south southeast at 14 to 24 knots,
but then we likely lose the gusts by 00-02z. LLWS develops at KOFK
02-10z with winds at 1300-1500 feet from the southwest at 40-45
knots. This LLWS then develops at KLNK/KOMA 05-13z with similar
speeds. And then winds do eventually turn the northwest 15-18z as
a front moves into the region, and increasing again to 16 to 32
knots. There are 20% chances for a shower at various times through
the forecast, but too low to mention with certainty in the TAF
forecasts at this time.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...None.
IA...None.
&&
$$
DISCUSSION...Fajman
AVIATION...DeWald