Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 07/24/24
See below for an aviation forecast discussion for the 00Z TAFs.
&&
.SHORT TERM /THIS EVENING THROUGH WEDNESDAY NIGHT/...
Issued at 332 PM CDT Tue Jul 23 2024
Scattered showers and thunderstorms will remain possible over
portions of eastern South Dakota into this evening, mainly across
the Prairie Coteau region with the assistance of a bit of lift
thanks to the terrain. The first showers popped up around 20Z just
southeast of Clear Lake/Brandt. These showers and weak thunderstorms
should slowly diminish in coverage with the loss of daytime heating.
Our hazy/milky sky will continue as elevated smoke moves in from
Canadian and western U.S. wildfires. The coverage of this smoke
extends west through MT/WY and southern ID/eastern OR. While smoke
nearing the surface remains difficult to forecast, the HRRR
continues to indicate the higher potential of surface smoke
currently over the area pushing mainly west of the MO River after
midnight before pushing across much of the area again Wednesday
afternoon. As a result, and with visibility down to around 5-8SM
over much of ND, have been able to add haze to our forecast where
the thicker smoke is forecast mainly during the daytime/evening
hours before pushing east.
Very warm air will be the main concern over the next several days as
an upper level ridge of high pressure shifts across the Northern
Plains. After lows in the mid 60s, temperatures will rise into the
80s to mid 90s Wednesday afternoon. The highest temperatures will
remain over central South Dakota. The 500mb high over the
southwestern U.S. extends a ridge through MT and Saskatchewan, with
the Dakotas and MN in north to northwesterly flow. The ridge will
push east over western SD and ND through much of central Canada
Wednesday night.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
Issued at 332 PM CDT Tue Jul 23 2024
The long term portion of the forecast will feature above average
temperatures with periods of showers and thunderstorms over the
weekend.
The period begins on Thursday with an upper level ridge over the
Northern Plains with warm southerly flow. High temperatures should
warm into the mid 80s, over eastern SD, while areas along and west
of the Missouri river climbs into the upper 90s to around 100
degrees. The probability of seeing 100 degrees off the NBM is 15 to
40% for the Missouri valley and points west. The ridge shifts east
some on Friday, with southerly flow remaining over the CWA. 700 mb
temps warm slightly, reaching +13C. The probability of 100 degrees
spreads east some, with the James River valley seeing a 20 to 30%
chance. An upper level trough crossing southern Canada will bring
slightly cooler temps on Saturday, along with a 20-40% chance for
pcpn Friday night. North central SD will have the best potential of
seeing pcpn.
A slowly moving surface low pressure system and upper level trough
will cross the region over the weekend with additional chances for
pcpn. Rainfall chances are best, 20-45%, Saturday night, with
slightly lower potential Sunday night. Temperatures remain warm with
highs in the 80s and 90s for the weekend and into early next week.
&&
.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 603 PM CDT Tue Jul 23 2024
Terminals KABR,KATY,KPIR,KMBG
Mainly VFR/MVFR conditions (visby) are forecast over the next 24
hours. The main concern will be near surface smoke. We will also
continue to monitor convection potential (mainly KATY) through
late this evening.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...None.
MN...None.
&&
$$
UPDATE...Dorn
SHORT TERM...KF
LONG TERM...SD
AVIATION...Dorn
Area Forecast Discussion
National Weather Service La Crosse WI
1048 PM CDT Tue Jul 23 2024
.KEY MESSAGES...
- Scattered storms into early evening, mostly holding over northeast
IA and southwest WI. A few could be strong with gusts from 40 to 50
mph. Small hail possible. Isolated severe not ruled out. .
- Drier, seasonable end to the work week.
- Warmer, more humid moving into the weekend and next week. Storm
chances also return.
&&
.DISCUSSION...
Issued at 215 PM CDT Tue Jul 23 2024
* SCATTERED STORMS INTO TONIGHT: a few strong into early evening.
Low end chances linger into Wed morning (20-30%) for northeast
IA/southwest WI
Currently, storms continue to fire in an increasing MLCAPE pool from
1500-2500 J/kg over northeast IA with the aid of a ripple in the
upper atmosphere, a sinking west-east running sfc boundary, and
probably more importantly, outflow boundaries from the convection
itself. Some have been strong already with gusts from 35 to 50 mph.
They are also capable of hail but have not seen any ground truth
yet. Lightning was fairly sparse earlier in the afternoon but have
seen an uptick over the past 1/2 hour.
These storms will continue to spark in the instability and the
numerous forcing mechanisms. Trends/locations favor keeping much of
the convection across northeast IA/southwest WI southward - with
latest CAMS models holding the bulk just south of the local area.
Given the persistent cloud cover in the north and how the current
storms are laying out/developing - this looks reasonable. Strong
storms will remain possible into early evening and can`t rule out a
severe storm or two.
Instability will be on the wane with the loss of daytime hearing, but
the RAP holds onto a 1000 J/kg MLCAPE pool from southwest MN through
the better part of IA into northern MN. Moisture transport and a
slight uptick in the 850 mb jet will work in this area, and along
the aforementioned sfc boundary. Low end chances (20-30%) will
persist through the overnight...hanging around into Wed morning
until the upper level trough helps push the sfc front/unstable air
more farther south/southeast.
* WED INTO THE SATURDAY: drier, seasonable
Long range guidance remains in very good agreement with shifting an
upper level ridge from the rockies eastward this week, moving the
ridge axis across the upper mississippi river valley by 00z Sat. All
the WPC clusters agree with only minor differences in
strength/location.
Sensible weather outcomes are to keep the local area dry as the main
storm track shifts to the east side of the ridge. Seasonable temps
to start, but some warming starts to pool in by the weekend.
* SUNDAY INTO NEXT WEEK: warmer, storm chances return
The ridge and sfc high pressure shift east by Sunday with the upper
level flow looking to become more zonal-broad ridging. With more of
a southerly fetch to the lower levels, warmer and more moist air
looks to return to the upper mississippi river valley. The 25/75%
for highs show minimal spread within both EPS and GEFS members -
roughly 5 degrees through the middle part of next week...solidly in
the mid 80s for most locations` highs. Upper 10% of the EPS pushes
some highs north of 90 degrees. The CPC 6-10 outlook also favors a
period of higher heat with 60-70% chances for above normal temps
from the 28th into the start of Aug. Further, NAEFS and EPS 850mb
temp anomalies are +1 - and expect these will likely climb as we
move into next week. A lot of signals all saying the same thing -
it`s going to get warm.
With the change in the overall pattern expect an increase in pcpn
chances as various shortwave troughs will have a better opportunity
to traipse across/near the area.
&&
.AVIATION /06Z TAFS THROUGH 06Z THURSDAY/...
Issued at 1049 PM CDT Tue Jul 23 2024
Low chances (20 to 30%) of precipitation through the night for
areas south I-90 with northeast Iowa seeing the best chance of
rain to occur. Precipitation chances diminish heading into mid-
morning on Wednesday. Predominant light northeast winds are
expected. The main focus for this period will be if fog or a low
stratus deck develops. Low level clouds, between 2kft and 5kft,
are expected to develop during the early morning hours and may
inhibit fog formation. The area with the best chance for fog to
develop looks to be for areas west of the Mississippi. This area
has a 30 to 50% chance of fog developing. By mid-morning, any
fog that does develop will dissipate and the low-level clouds
will decrease in coverage through the rest of the morning.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
IA...None.
&&
$$
DISCUSSION...Ferguson/EMS
AVIATION...Cecava
Area Forecast Discussion
National Weather Service Cheyenne WY
549 PM MDT Tue Jul 23 2024
.KEY MESSAGES...
- Smoke from wildfires in Canada and the northwest US will
continue to slowly drift southeast over WY and NE. An Air
Quality Alert has been issued and folks sensitive to smoke
should limit outdoor activity.
- Hot and largely dry weather is expected for Wednesday and
Thursday.
- Monsoonal moisture will return to the area late Thursday
through Saturday, leading to increased chances for showers and
thunderstorms on Friday and Saturday.
&&
.SHORT TERM /THROUGH WEDNESDAY NIGHT/...
Issued at 258 PM MDT Tue Jul 23 2024
A ridge of high pressure will continue to dominate the weather
pattern over the western CONUS from today through Wednesday evening.
Mid-level temperatures will continue to steadily rise each day, with
deeper mixing and resultant surface temperature increases of around
4-6 degrees each day. Expect afternoon highs around 3-5 degrees
above average today, with highs 5-10 degrees above average by
Wednesday afternoon. A stray shower is possible in far northwestern
Carbon County later this evening, however the remainder of southeast
Wyoming and western Nebraska will remain dry under strong subsidence
from the high pressure system. Smoke from northwestern and Canadian
wildfires will remain in place today with very little surface and
mid-level flow to move it out of the area. An Air Quality Alert for
surface particulate concentrations has been issued by the WY DEQ for
today through 1pm on Wednesday. Folks sensitive to poor air quality
should limit their time outdoors today.
Ridging will continue on Wednesday with the aforementioned increase
in afternoon high temperatures expected. A few very isolated showers
are possible in the higher terrain of the Snowy and Sierra Madres on
Wednesday however again the vast majority of the CWA will remain dry
and nearly cloud-free. Smoke may begin to drift a bit farther east
on Wednesday as the ridge axis approaches from the west and
northwest flow aloft slowly pivots to west-northwest. However,
expect another day of notably hazy skies. Forecast confidence is
high throughout the short-term and only minimal adjustments to smoke
grids and PoP grids were made in this forecast package.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
Issued at 258 PM MDT Tue Jul 23 2024
Thursday looks like the hottest day this week. A fairly potent
trough moving into the Pacific NW will nudge the ridge axis eastward
to become positioned more or less over our area by midday Thursday.
The inter-quartile range of 700-mb temperatures over KCYS is around
+18 to +19C, indicating support for very hot temperatures around 10F
warmer than average for this time of year. The limiting factor looks
to be cloud cover. As the ridge of high pressure aloft gets squashed
to the southeast, a plume of monsoon moisture on its western flank
will begin to rotate back into our area. Expect increasing cloud
cover from the west as moisture aloft increases fairly rapidly
during the day on Thursday. This may prevent record highs, but
several locations will be within a few degrees. The moisture
may arrive too late to be enough to produce widespread afternoon
showers and thunderstorms, but there is enough for a few
scattered storms mainly west of the Laramie range and fairly
late in the day/evening.
The longwave trough will stay locked in over the Pacific northwest
states on Friday through the weekend, with numerous shortwaves/vort-
maxes rotating through. This will push the ridge axis well to our
east for a few days with southwest flow left aloft. Precipitable
water is expected to rise rapidly from around 0.5" at KCYS Thursday
morning to over 1.0" by Friday afternoon as the southwest flow aloft
tilts the monsoon plume across our area. This will be near the 90th
percentile of climatology, giving support for a more active day of
afternoon convection. Lift will be aided by the passage of a modest
vort-max that at least currently looks to be well timed with
afternoon peak heating. PW is expected to drop slightly for
Saturday, but should still be sufficient to produce another round of
showers and thunderstorms across the area, though possibly not as
widespread as Friday. Overall storm threats look to be primarily
locally heavy rainfall and gusty winds. The shear looks pretty weak
owing to the light winds aloft, reducing but certainly not
eliminating the threat for large hail. Temperatures Friday and
Saturday will be still a few degrees above average with 700-mb
temperatures around +15C, but we should be cooler than Thursday.
Our brief monsoon pattern will wind down Sunday as the longwave
trough starts to lift out of the northwest CONUS and the southwest
ridge begins to re-organize and strengthen. Look at another warming
trend Sunday through Tuesday. NAEFS 700-mb temperatures are already
running around the 90th percentile of climatology by Monday and
Tuesday, supporting a return of widespread 90s to lower 100s. While
deterministic models are showing a fairly extreme heat event, this
doesn`t quite have the ensemble support just yet. Regardless, it
will be hot. The 25th percentile of the ensemble 700-mb temperatures
over KCYS is still around +18C through early next week.
&&
.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 545 PM MDT Tue Jul 23 2024
Mostly clear skies across southeast WY and western NE early this
evening with isolated showers ongoing along the higher terrain
and across central WY. These showers with occasional thunder
will approach KRWL before 03z this evening with gusty winds
possible. Otherwise, the main concern during the forecast period
will be smoke leading to marginal visibility reductions. Most
terminals should remain at or above 6SM. KAIA is currently
reporting 5SM which coincides with the HRRR Smoke showing higher
near-surface concentrations in the area through 04z this
evening.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...Air Quality Alert until 1 PM MDT Wednesday for WYZ101>119.
NE...None.
&&
$$
SHORT TERM...MAC
LONG TERM...MN
AVIATION...MB
Area Forecast Discussion
National Weather Service Indianapolis IN
930 PM EDT Tue Jul 23 2024
.KEY MESSAGES...
- Isolated afternoon showers and a few storms are possible today
with better chances Wednesday PM
- Locally heavy rainfall will be the main threat from storms
- Wildfire smoke at times which may reduce visibility and air
quality
- Seasonable temperatures in the 80s through this weekend gradually
warming into early next week
&&
.FORECAST UPDATE...
Issued at 930 PM EDT Tue Jul 23 2024
Despite a lack of any significant focusing mechanism or shear,
isolated airmass convection continues to pop up across portions of
central Indiana, with somewhat of an axis apparent regionally along
and north of the I-70 corridor in a zone of very weak surface
convergence. This convection should not linger too much longer as
the boundary layer begins to stabilize, though have extended slight
chances through about midnight northwest, as an outflow boundary
from upstream convection over northern Illinois may impinge upon
that area in the next couple of hours and possibly spark a few more
showers and storms. As the night wears on, expect convection to die
out as low level stabilization continues.
Patchy fog may develop overnight in preferential areas, primarily in
the Wabash and White river valleys, and have added some fog to the
grids as a result. This should be a bit more limited than last night
and dense fog is not expected, though a few patches here and there
cannot be ruled out.
Dewpoints will remain fairly high as low level moisture continues to
pool along a stationary boundary to the south and the approaching
weak cold front to the north. Forecast lows generally in the mid 60s
continue to look good and only minor tweaks were made.
&&
.SHORT TERM (This evening through Wednesday)...
Issued at 258 PM EDT Tue Jul 23 2024
Latest IND ACARS soundings and SPC Mesoanalysis show a modestly
unstable air mass over central Indiana. This is also evident on
satellite, as diurnal cumulus have quickly developed upon reaching
our convective temperature (low to mid 80s). A few shallow rain
showers have developed, but these are far and few between. Soundings
and model data indicate that broad subsidence exists over the
region. This, combined with dry air aloft, will limit shower
development during the afternoon hours.
Overnight, we can expect any lingering cumulus to diminish after
sunset. Mainly clear skies along with light surface winds may lead
to some patchy fog by morning. The best chance of this is in our
typically fog-prone locations (along rivers, valleys, open fields,
corn fields).
A cold front is likely to trigger convection this evening over
southern Wisconsin or northern Illinois. Some CAMS have this
activity congealing into a cluster or broken line and propagating
southward towards Indiana. There is a low probability that this
activity reaches our northwestern counties early in the morning
hours. This will depend on the strength and orientation of the low-
level jet that is likely to develop overnight.
Aside from convection, increasing wildfire smoke may lead to reduced
air quality at times. High resolution smoke models indicate that a
plume of denser smoke may arrive Wednesday morning. While smoke
currently in the air is mainly aloft, models are showing a greater
component of near-surface smoke that may begin to reduce visibility
at times, especially north of Indianapolis.
CONVECTIVE POTENTIAL AND HAZARDS
Convection looks to redevelop Wednesday afternoon along the front,
where ever it ends up. There exists some spatial and temporal
uncertainty within guidance regarding the location of the front by
early afternoon. Despite this uncertainty, the front is most likely
to reside over the northern half of Indiana. Best timing for storm
development is after 16-18z or so.
Taking a deeper dive into Wednesday`s convective potential, we see
some variability within CAM guidance. The bulk of this variability
arises from differences in cold front timing/location. CAMs seem to
be in good agreement that convection will fire up in the afternoon
and trek southeastward with time. Model soundings show steep low-
level lapse rates that become more modest with height. Despite the
meager mid-level lapse rates, MLCAPE values are quite decent (over
2000 J/Kg). Some mid-level dry air exists as well, leading to about
1000 J/Kg DCAPE. Hodographs show very little shear below 300mb, and
storms may behave more like single-cell/pulse storms or multicell
clusters. The strongest of these may promote a brief downburst or
hail threat.
&&
.LONG TERM (Wednesday night through Tuesday)...
Issued at 258 PM EDT Tue Jul 23 2024
The long term period will start off with chances for thunderstorms
as an upper low pushes off to the NE. Convection is expected to stay
below severe levels but a few cells could produce locally heavy rain
and brief gusty downbursts. The line of storms will be concentrated
to the southern half of the forecast area by midday Thursday,
finally exiting to the SE by the evening. Meanwhile, upper ridging
will be centered over the SW states, stretching towards the Great
Lakes through the weekend. At the surface, high pressure will settle
in behind the exiting system, allowing for dry weather over the
weekend and warming temperatures for the remainder of the long term.
Looking towards next week is a bit more uncertain as models are
showing a variety of solutions. There is a possibility that there
could be a stalled system and return southerly flow over the region
that could lead to a conveyor belt of scattered showers and
thunderstorms throughout early next week which could start as early
as Sunday. For now, keeping with the slight chance and chance PoPs
throughout the latter half of the period.
Temperatures will start out with low to mid 80s, warming to upper
80s for the rest of the period. The latter half of the period will
also see overnight lows near 70 degrees.
&&
.AVIATION (00Z TAF Issuance)...
Issued at 706 PM EDT Tue Jul 23 2024
Impacts
- Patchy fog possible overnight.
- Scattered showers and storms possible Wednesday as a front sags
into the area. Brief MVFR restrictions possible.
- Potential for transient visibility reductions from smoke transport
into the region.
Discussion:
Predominantly VFR conditions through the period.
Winds will be light to occasionally calm overnight tonight as a weak
surface pressure gradient exists despite approach of a weak cold
front.
These light winds may promote some patchy fog, though uncertainty is
high and impact will likely be limited. Have carried 6SM at the
outlying sites as a nod to this potential and will monitor
conditions through the evening.
As we go into Wednesday, the aforementioned boundary will sag into
the area, allowing winds to become more westerly in nature with time
late in the period, and increasing shower/storm chances. Will carry
VCSH during the day tomorrow as a suggestion of this potential, as
timing and impact at any one point remains quite uncertain.
Potential will exist for MVFR restrictions wherever showers/storms
develop, and potentially for a time along the front itself.
Additionally, satellite obs and HRRR smoke progs suggest an increase
in transport of upstream wildfire smoke into the area. There will be
at least some potential for transient visibility reductions in smoke
or haze as a result of this, and will carry 6SM in HZ all sites
tomorrow.
&&
.IND WATCHES/WARNINGS/ADVISORIES...None.
&&
$$
UPDATE...Nield
SHORT TERM...Eckhoff
LONG TERM...KF
AVIATION...Nield
Area Forecast Discussion
National Weather Service North Platte NE
646 PM CDT Tue Jul 23 2024
.KEY MESSAGES...
- Above normal temperatures are likely over the next several days
with highs generally in the 90s.
- Fire weather concerns will become elevated Thursday with the
possibility of critical fire weather conditions in western areas
Friday and Saturday (zones 204 and 210).
- Beyond Thursday, there are only minor chances for
precipitation, mainly over the northern half of the forecast
area.
&&
.SYNOPSIS...
Issued at 308 PM CDT Tue Jul 23 2024
H5 analysis this morning hand high pressure located over
Death Valley California. Ridging extended north northeast of this
feature into southeastern portions of the NW Territories of Canada.
East of this feature, a positively tilted trough of low pressure
extended from southern portions of Hudson Bay, southwest into
central Texas. West of the ridge, closed low pressure was located
off the central coast of British Columbia. Across the central,
southern and northern plains, northerly flow was noted and extended
from western North Dakota into the Texas Panhandle. At the surface,
a broad area of high pressure was centered over the central plains.
A diffuse frontal boundary extended from central Texas, east
northeast into the Tennessee Valley. Skies were clear this afternoon
across the area, however, smoky conditions aloft, has led to hazy
skies this afternoon. Temperatures as of 3 PM CDT ranged from 83
degrees at Broken Bow to 91 degrees in Valentine. In the
extended, the initial forecast issue will be fire weather
concerns and red flag potential (particularly in the western
portion of the forecast area) Friday and Saturday. For Thursday,
ridging aloft will persist from the Four Corners, northeast
into North Dakota. East of the ridge, hot temperatures will
continue across the forecast area. Winds will shift around to
the south Thursday and minimum RH will reach 15 to 20 percent in
the west. Looking at BUFKIT forecast soundings Thursday, mixed
layer winds remain fairly light at 15 MPH or less. This combined
with RH of 15 to 20 percent will lead to elevated fire weather
conditions across the western third of the forecast area.
Beginning Friday, the ridge will break down as a trough of low
pressure migrates into western Canada and the Pacific NW.
Downstream of this feature, southerly winds will increase during
the afternoon hours Friday and Saturday. With minimum RH around
15 percent, we have a good threat for reaching red flag
conditions in zones 204 and 210 both Friday and Saturday
afternoon. In addition, both days will see a surface trough
anchored across the western panhandle. INVOF this trough, the
GFS and NAM12 solns develop some convection Friday
afternoon/evening and Saturday afternoon/evening. Forecast
soundings indicate high based storms with little to no
precipitation-ie. dry lightning threat. Will hit the fire
weather concerns with this afternoon`s hazardous weather
outlook. By Sunday, the trough will migrate east into central
Nebraska. Behind the trough, very dry air will push into western
Nebraska resulting in critical RH values Sunday afternoon.
Winds behind the trough do not appear strong attm, and may
alleviate some fire weather concerns. Hot temperatures will
continue into next week with readings topping out in the upper
90s to near 100 Monday and Tuesday.
&&
.SHORT TERM /THROUGH WEDNESDAY/...
Issued at 308 PM CDT Tue Jul 23 2024
Benign weather conditions are expected over the next 36 hours.
The main forecast issue will continue to be smoke aloft and hazy
skies across the area. The 12z HRRR vertically integrated smoke
product, continues to indicate a decent threat for smoke to
persist through Wednesday night across the area. ATTM the best
potential is across most of the CWA tonight into Wednesday, with
the eastern half of Nebraska more favorable Wednesday night. As
for near surface smoke potential, it is greatest this afternoon
and evening over western portions of the forecast area.
Overnight there are indications in the 12z HRRR that smoke
concentrations will decrease with this persisting into Wednesday
night. That being said, will probably continue the mention of
haze in the forecast, to some degree over the next 36 hours.
Ridging aloft will migrate to the east through Wednesday night
with the ridge axis extending from eastern Utah into western
North Dakota by 12z Thursday. This will push warmer air into the
forecast area beginning Wednesday, allowing highs to reach into
the 90s across the area. Minimum RH will approach 20 percent in
the eastern panhandle and far SW Nebraska Wednesday afternoon,
however winds will be light and variable at under 10 MPH which
should keep fire weather concerns very limited. Lows tonight and
Wednesday night will generally be in the lower 60s, with some
upper 50s possible in western areas where drier air is in place.
With respect to fog potential tonight. Earlier this morning, we
had some patchy fog across the forecast area. Took a look at
the NAM12 and HRRR surface visibility forecasts and probability
forecast from the SREF, and the best potential for fog appears
to be off to the northeast of the forecast area. With this in
mind, will forgo a mention of fog with this afternoon`s forecast
package.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
Issued at 308 PM CDT Tue Jul 23 2024
In the extended, the initial forecast issue will be fire
weather concerns and red flag potential (particularly in the
western portion of the forecast area) Friday and Saturday. For
Thursday, ridging aloft will persist from the Four Corners,
northeast into North Dakota. East of the ridge, hot temperatures
will continue across the forecast area. Winds will shift around
to the south Thursday and minimum RH will reach 15 to 20
percent in the west. Looking at BUFKIT forecast soundings
Thursday, mixed layer winds remain fairly light at 15 MPH or
less. This combined with RH of 15 to 20 percent will lead to
elevated fire weather conditions across the western third of the
forecast area. Beginning Friday, the ridge will break down as a
trough of low pressure migrates into western Canada and the
Pacific NW. Downstream of this feature, southerly winds will
increase during the afternoon hours Friday and Saturday. With
minimum RH around 15 percent, we have a good threat for reaching
red flag conditions in zones 204 and 210 both Friday and
Saturday afternoon. In addition, both days will see a surface
trough anchored across the western panhandle. INVOF this trough,
the GFS and NAM12 solns develop some convection Friday
afternoon/evening and Saturday afternoon/evening. Forecast
soundings indicate high based storms with little to no
precipitation-ie. dry lightning threat. Will hit the fire
weather concerns with this afternoon`s hazardous weather
outlook. By Sunday, the trough will migrate east into central
Nebraska. Behind the trough, very dry air will push into western
Nebraska resulting in critical RH values Sunday afternoon.
Winds behind the trough do not appear strong attm, and may
alleviate some fire weather concerns. Hot temperatures will
continue into next week with readings topping out in the upper
90s to near 100 Monday and Tuesday.
&&
.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 639 PM CDT Tue Jul 23 2024
VFR conditions will prevail over the next 24 hours. There will
be some haze in the air from wildfire smoke, however no impacts
to surface visibility are expected at this time. Winds will
remain light tonight through tomorrow afternoon, generally 6 kts
or less.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...Buttler
SHORT TERM...Buttler
LONG TERM...Buttler
AVIATION...Gomez
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
634 PM CDT Tue Jul 23 2024
.KEY MESSAGES...
- Quiet weather for the second half of the work week.
- Much warmer this weekend (upper 80s/low 90s), with the return
of shower and thunderstorm chances. Very unsettled in the
extended forecast.
&&
.DISCUSSION...
Issued at 149 PM CDT Tue Jul 23 2024
The organized complex of morning convection has drifted south into
Iowa early this afternoon. Observations reveal that a cold front
extends from the Lac Qui Parle/Swift county line to the southeast
towards Mankato, extending further east towards Rochester. Locations
to the south of this boundary will be the focus point for any
renewed convection in the coming hours. RAP forecast soundings and
mesoanalysis reveal 1500+ j/kg of MLCAPE and sufficient, though weak
shear across this area. A few stronger cells will be possible mainly
southwest of the Minnesota River, however the threat for severe
weather appears low. The remainder of the day will be dry for most
locations north of the frontal boundary, with just a slight chance
for an isolated shower. Filtered sunshine will be the theme and any
clearing in the skies will likely appear hazy given a lingering
concentration of wildfire smoke aloft. Temperatures are on track to
reach the low to mid 80s across western Minnesota and the mid to
upper 70s across eastern MN and western WI.
The cold front will drift south over the next few days, followed by
the arrival of expansive surface high pressure across the Upper
Midwest into the Great Lakes that will bring quiet weather for the
remainder of the work week. Areas of patchy fog may develop
overnight, which appears largely dependent on where skies clear
(most favorable across southwestern MN). Any fog that develops will
mix out of the picture quickly Wednesday morning. Temperatures are
forecast to gradually warm each of the next few days, with highs in
the mid to upper 70s Wednesday, the low 80s Thursday, and into the
mid 80s on Friday. Comfortable levels of humidity will gradually
increase by late week, however the more notable heat and humidly
will hold off until the weekend.
Late July heat, humidity, and storm chances will return to the
forecast starting on Saturday. Forecast highs climb into the upper
80s/low 90s Saturday & Sunday, along with dew points forecast to
reach the upper 60s and perhaps the low 70s by the end of the
weekend. The eastward expansion of the upper level ridge and quick
suppression of the ridge due to an incoming potent upper low
adds uncertainty into just how warm it will get, but leaning on
the blended guidance seems like a reasonable call at this time.
The eastward progression of the aforementioned upper low will
bring the return of shower and thunderstorm chances. For now,
most of Saturday looks dry, with only slight chance PoPs in
place across western Minnesota. The more likely scenario for
scattered to perhaps even widespread convection will be Sunday
as a cold front moves through.
Global ensemble guidance is in strong agreement that a 590s dm
ridge centered over the central Great Plains will amplify early
next week. Locally, the extended guidance has trended warm, with
upper 80s and low 90s sticking around through much of next
week. Along with the warmth, pattern recognition resembles the
classic Summer "ring of fire" where multiple rounds of storm
complexes move around the periphery of the ridge along the
instability axis. As we`ve seen over the past few weeks, this
can often mean the potential for a bowing MCS/damaging wind
threat so that will be something to watch heading into next
week. This is simply a "heads up" that things appear to be
trending in a more active direction from the second half of the
weekend into much of next week.
&&
.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 634 PM CDT Tue Jul 23 2024
Clouds are dissipating early this evening and will continue to
do so over the next few hours. Smoke aloft will continue through
the period. Winds will be easterly around 5 kts tonight and
Wednesday.
KMSP...No additional concerns.
/OUTLOOK FOR KMSP/
THU...VFR. Wind SE 5kts.
FRI...VFR. Wind SE 10-15kts.
SAT...VFR. Wind S 15G25kts.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...None.
WI...None.
&&
$$
DISCUSSION...Strus
AVIATION...Borghoff
Area Forecast Discussion
National Weather Service Pocatello ID
852 PM MDT Tue Jul 23 2024
.UPDATE...A quick update to account for a few lingering showers
and storms across the central mountains...and extending that
chance through midnight. Otherwise, things look on track for the
rest of the night. A few showers (or even a lightning strike or
two) is possible just before sunrise in the central mountains and
the Magic Valley ahead of tomorrow`s storms. Keyes
&&
.PREV DISCUSSION... /issued 249 PM MDT Tue Jul 23 2024/
SHORT TERM...Tonight and Wednesday
A high pressure system in the Great Basin will keep temperatures
elevated through Wednesday. Most of the lower elevations
throughout East Idaho will have temperatures in the high 90s to
low triple digits with nighttime lows in the low to mid 60s.
Accordingly, a heat advisory remains in effect for most the Snake
Plain, Eastern Magic Valley, and Southern Hills until Wednesday
evening. Cloud development this afternoon is currently limited to
locations at elevation. Could see a few isolated showers and
thunderstorms develop over these areas but the best chances for
thunderstorms will be focused in the Central Mountains and in the
Southern Hills for the rest of today.
As we get into the overnight hours, things will quiet down with
light winds and not much in the way of precipitation expected. A
few CAMs suggest a very isolated shower/storm may pop up around
sunrise in the central mountains so added low-end PoPs accordingly
to account for this potential. The greater chance for PoPs will
be as we get into the afternoon and evening Wednesday as moisture
looks to increase significantly region-wide compared to previous
days. Just about everyone has at least some potential for a shower
or thunderstorm with the biggest concern being for increased
lightning activity (see fire weather discussion) and gusty outflow
winds across the area. Cheze / McKaughan
LONG TERM...Thursday through Next Tuesday.
By Thursday, our Pacific trough will still be moving through the
West and continue to bring us isolated to scattered showers and
thunderstorms. It will also increase wind gusts on Thursday with
the highest gusts around 35 mph in the Arco Desert region and
upper Snake Plain. Elsewhere, gusts will range from 25 to 35 mph.
The storm activity continues to get pushed a bit farther east on
Friday, so have kept about a 20 to 30 percent chance in the South
Hills and Eastern Highlands, but much of the area will stay dry.
On Saturday, a weak shortwaves passes through the area and will
bring another chance for isolated to scattered showers and storms.
Afternoon winds will remain elevated through the weekend with
gusts on Friday of 25 to 35 mph and 20 to 30 mph on Saturday and
Sunday. This system will help drop our temperatures a few degrees
with highs falling into the mid 80s for most by Saturday. It`s a
short-lived cool down though, so we warm right back into the low
90s by Monday. AMM
AVIATION...
VFR conditions expected through the period with light and variable
winds at most east Idaho terminals. KSUN will see their usual
diurnal wind cycle along with the potential for some showers and
thudnerstorms this afternoon. Just beyond the current 18Z forecast
period, showers and thunderstorms chances will increase
regionwide requiring the need in subsequent forecasts for VCSH or
VCTS wording. Winds will remain light for the first half of the
day Wednesday but will increase to around 10-15 kts at KPIH, KIDA
and KBYI so it`ll be a touch breezier compared to the past few
days with some gustier winds possible in and around any
thunderstorms that develop. McKaughan
FIRE WEATHER...
A RED FLAG WARNING is in effect for fire weather zones 410, 422,
425, 427, 475, and 476 for Wednesday due to forecast scattered
thunderstorm activity. A Pacific low moving through British
Columbia will flatten our ridge enough to bring in a decent push
of moisture to fire off thunderstorm activity Wednesday afternoon
through the evening. We are expecting a mix of wet and dry storms
with gusts from storms around 45 to 55 mph with the potential for
one or two storms to produce gusts closer to 60 mph. The HREF is
only giving a 20 to 30 percent chance of wind gusts exceeding 45
mph on Wednesday, though it seems like it doesn`t catch convective
gusts quite as while when viewing probabilities. In contrast, the
HREF 10 meter AGL max ensemble gust DOES show the potential for a
storm or two to produce gusts near 60 mph. The SPC has even
placed the Central Mountains in the "Marginal" risk for severe
weather. There will be more isolated to scattered storms on
Thursday and an increase in wind gusts to 25 to 35 mph across
almost all of Eastern Idaho. So, even though min RHs will increase
on Thursday, the combo of Wednesday`s lightning activity and
increasing winds on Thursday may warrant an extension of the
current RED FLAG WARNINGS into Thursday. Friday looks to be a bit
"quieter," though it will still be breezy. A shortwave trough
moves through on Saturday to bring isolated to scattered
thunderstorm activity back into the forecast. AMM
AIR QUALITY...
Local and regional wildfires continues to produce primarily
"Moderate" air quality conditions across the region. HRRR Smoke
model indicates that conditions should remain mainly moderate into
Wednesday. 13
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning from noon Wednesday to midnight MDT Wednesday
night for IDZ410-422-425-427-475-476.
Heat Advisory from noon to 10 PM MDT Wednesday for IDZ051>059-
075.
&&
$$
Area Forecast Discussion
National Weather Service Reno NV
102 PM PDT Tue Jul 23 2024
.SYNOPSIS...
* Thunderstorms will bring locally heavy rain and flash flood
potential along with strong outflow gusts through Wednesday.
* Storms become more isolated over western NV Thursday as drier
air brings an end to storms for late week into the weekend.
* Gusty southwest winds and more seasonal temperatures return
Thursday and Friday with locally critical fire weather
conditions.
&&
.DISCUSSION...
THUNDERSTORMS:
* Thunderstorms will again fire along the Sierra around midday
through Wednesday with storms pushing off or developing off
outflows into western NV during the afternoons. Abundant
moisture and instability are present as noted by the 0.81" PWAT
in the KREV sounding this morning with sufficient clearing to
help temperatures climb well above average for late July. The
HREF is showing an uptick in PWATs Wednesday as deeper moisture
expands northward across western NV and far northeast CA (PWAT
1.00"+) as the ridge axis slides east and upper level southerly
flow increases ahead of an advancing trough in the PacNW.
* For this afternoon/evening, storm mode will be similar to Monday
with slow storm motions and the potential for very heavy rain
producers, especially across the eastern Sierra into far western
NV. A few severe storms with gusts to 60 mph and nickle sized
hail are possible, but flash flooding will be the bigger concern
as storms move slow or anchor near steep terrain and burn scars.
* For Wednesday, mid level S/SW winds increase which will both
increase storms motions a bit while also resulting in increased
shear for storm organization. Storm coverage will expand across
northeast CA and northwest NV where HREF probabilities indicate
gusts > 50kts have increased (10-30%) with SPC introducing a
marginal risk for severe wind gusts near the Oregon border.
Farther south, storms are expected to initiate over the eastern
Sierra and propagate into western NV during the afternoon.
Similar severe weather threats will exist with the additional
threat for stronger outflows and blowing dust reaching the Basin
and Range. While storms will be moving quicker, training of
cells will continue to bring a heightened threat for flash
flooding for areas south of I-80 with focus on the eastern
Sierra into southern Lyon and Mineral counties.
* For Thursday, drier and more stable air will confine storms to
the Basin and Range where activity will be more isolated but
still capable of gusty outflows and areas of blowing dust. Dry
and cooler conditions persist Friday into the weekend with
temperatures returning to seasonal normals.
WIND/SMOKE:
* South-southwest winds increase Thu-Fri ahead of a trough moving
through the PacNW and another feature moving inland from off the
northern CA coast. Latest ECMWF EFI highlights northeast CA and
northwest NV for Thursday afternoon when blended guidance
showing gusts 30-35 mph for several or more hours along the
Sierra Front and areas north of I-80. 700MB flow 15-25 kts
across northeast CA and northwest NV Thursday shifts southward
toward the Nrn Sierra and far western NV Friday although the EFI
signal is not as pronounced. Still, breezy winds are expected
to shift into these areas Friday afternoon with increased chop
for Lake Tahoe.
* Smoke transport will be tricky and depend heavily on fire
activity. Latest HRRR suggests smoke from the fires near Portola
will remain localized to the fire this evening, maybe drifting
briefly into far western NV while producing a more pronounced
stream of smoke for late Wednesday. Of course, outflows may
interrupt smoke transport, so confidence is below average.
Increasing winds Thu-Fri should help disperse smoke, but as
winds weaken and turn northwest in the evening, some smoke could
reach far western NV for the overnight/morning hours with good
daytime mixing helping with the dispersal process.
&&
.AVIATION...
* Thunderstorms will again be the primary threat today and
Wednesday afternoons/early evenings, especially for eastern
Sierra (KMMH) and western NV airports. For this afternoon,
storms may impact KTVL-KTRK early before pushing off to the east
with a repeat pattern on Wednesday. Very heavy rain could bring
MVFR conditions underneath strongest storms while lightning and
outflow winds to 35+ kts possible vicinity of any storm.
Primary storm timing will be 20-23Z for Tahoe area TAFs and
21-03Z at other sites both days.
* A drier pattern returns late week with isolated cells/outflow
winds hanging on for one more day along the Hwy 95 corridor
(KLOL- KNFL-KHTH). Gusty southwest winds return Thu-Fri when
gusts will 25-30 kts.
&&
.FIRE WEATHER...
* Isolated to scattered storms persist through Wednesday most
areas with best coverages Eastern Sierra of Mono-Alpine Counties
into western NV where storm character will be wet with heavy
rainfall potential. Storm coverage will be more isolated for
Tahoe Basin northward along Hwy 89, but will still be capable of
producing isolated strikes and gusty outflow winds.
* One place to watch closely Wednesday afternoon/evening will be
Hwy 395 from Susanville northward to the Warners and far
northwest NV (north of Gerlach) as cells in these areas will be
moving much faster. While cells may train and still produce
wetting rains, the potential for isolated dry lightning strikes
increases.
* Isolated storms persist in the Basin and Range (Hwy 95 corridor)
Thursday as attention turns to increasing southwest winds and
drier air for late week. Southwest winds are expected to
increase from I-80 northward on Thursday then spread southward
on Friday. Right now, the strongest winds are slated for
Thursday along Hwy 395 from Reno to Susanville into northwest NV
and we have raised a fire watch for wind gusts 30-35 mph and
humidity falling below 15% for 3+ hours zones 270-278-458.
Enhanced winds and drier conditions will enhance ongoing fires
and threaten any holdovers even in areas outside the watch area
both Thu-Fri.
Hohmann
&&
.REV Watches/Warnings/Advisories...
NV...Fire Weather Watch from Thursday afternoon through Thursday
evening NVZ458.
Flood Watch through Wednesday evening NVZ001.
Heat Advisory until 8 PM PDT this evening NVZ004-005.
CA...Fire Weather Watch from Thursday afternoon through Thursday
evening CAZ270-278.
Flood Watch through Wednesday evening CAZ073.
&&
$$
Area Forecast Discussion
National Weather Service Tallahassee FL
914 PM EDT Tue Jul 23 2024
...New UPDATE...
.UPDATE...
Issued at 913 PM EDT Tue Jul 23 2024
No significant changes to the previous forecast appear necessary. A
moisture surge from the south and southeast will move into the area
later tonight with renewed development of showers and thunderstorms
along the coast during the early morning hours.
&&
.NEAR TERM...
(Through Wednesday)
Issued at 343 PM EDT Tue Jul 23 2024
After somewhat of a temporary reprieve from widespread convection,
wet weather is poised to return tomorrow. The culprits are a weak
tropical wave interacting with an upper trough just to our NW. An
abundance of moisture + favorable lift & upper diffluence via jet
streak right-entrance region should fuel scattered to numerous
showers and thunderstorms across the Tri-State area on Wednesday.
Axis of highest of highest precipitation begins offshore overnight
before reaching the coast (especially the FL Panhandle) in the early
morning, then spreads inland from SW to NE during the afternoon. The
18Z HRRR depicts this evolution fairly well. Heavy rain capable of
flooding will be the main concern. However, severe weather may be on
the table as the possibility still exists for an area of low
pressure to develop inland. If realized, then further convective
enhancement is plausible.
Given the expected abundant cloud cover and high storm coverage, the
high-temperature forecast went lower than the NBM and more in line
with the bottom range of MOS guidance. Look for upper 80s to low 90s
areawide. Widespread mid 70s are on tap for us overnight into the
early morning hrs.
&&
.SHORT TERM...
(Wednesday night through Thursday night)
Issued at 343 PM EDT Tue Jul 23 2024
Above average PoPs continue on Thursday as deep southerly flow
impinges on a stationary frontal boundary just northwest of the
region. This will cut down on highs, which are forecast closer
to normal in the upper 80s to lower 90s. The Hydrology section
has more details on flood potential.
&&
.LONG TERM...
(Friday through Monday)
Issued at 343 PM EDT Tue Jul 23 2024
The low to mid-level flow transitions from southwest on Friday to
northeast on Sunday as deep layer ridging retrogrades to the west
of the region. Short wave energy rotating around this feature will
augment daily seabreeze convection supporting above average PoPs.
Late this weekend into early next week, drier air may work into the
region, so PoPs could trend down if this trend continues.
&&
.AVIATION...
(00Z TAFS)
Issued at 720 PM EDT Tue Jul 23 2024
There are a few lingering showers around the area with an
isolated storm nearing KABY in the next hour or so. Otherwise, VFR
conditions are generally forecast to prevail through the night at
most sites. There is the potential for some fog at KTLH and KVLD
later tonight into Wednesday morning. There is the potential for
more rain later tonight along the coast, which may impact KECP and
KTLH in the predawn hours Wednesday. Rain and thunderstorms are
then expected to overspread the region from south to north later
Wednesday morning into Wednesday afternoon.
&&
.MARINE...
Issued at 343 PM EDT Tue Jul 23 2024
Southerly flow through the week with seas of 1 to 2 feet. Chances
of showers and thunderstorms each day, especially on Wednesday and
Thursday as a tropical wave traverses the waters. Any storms will
be capable of locally higher winds and waves, frequent lightning,
and the potential for waterspouts. Otherwise, tranquil boating
conditions.
&&
.FIRE WEATHER...
Issued at 343 PM EDT Tue Jul 23 2024
Fire concerns are minimal over the next few days as a wet pattern
resumes tomorrow through the remainder of the work week. For
Wednesday, widespread showers and thunderstorms are expected to
spread from south to north, beginning near the coast in the morning.
Wetting rains are likely for the Tri-State area. Lingering tropical
moisture keeps the precipitation forecast above normal. Otherwise,
look for very warm/muggy weather.
&&
.HYDROLOGY...
Issued at 343 PM EDT Tue Jul 23 2024
Over the next week, precip amounts will be above average across the
region. PWAT increases to around 2.2- to 2.3 inches from mid to late
week. Slow moving thunderstorms could bring excessive rainfall to
portions of the region. Isolated flash flooding is possible, mainly
in the more urbanized areas.
&&
.SPOTTER INFORMATION STATEMENT...
Spotter activation is not requested. However, spotters are always
encouraged to safely report significant weather conditions when they
occur by calling the office or tweeting us @NWSTallahassee.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 73 89 75 91 / 30 90 50 70
Panama City 78 87 78 90 / 50 90 60 70
Dothan 74 87 73 88 / 50 90 60 80
Albany 76 90 74 89 / 30 90 60 80
Valdosta 76 92 74 91 / 40 90 60 70
Cross City 76 92 75 92 / 60 90 60 60
Apalachicola 78 88 80 89 / 50 80 50 70
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AL...None.
GM...None.
&&
$$
UPDATE...DVD
NEAR TERM...IG3
SHORT TERM...LF
LONG TERM....LF
AVIATION...Reese
MARINE...LF
FIRE WEATHER...IG3
HYDROLOGY...LF