Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 07/04/23
Area Forecast Discussion
National Weather Service La Crosse WI
1055 PM CDT Mon Jul 3 2023
.DISCUSSION...(This evening through Monday)
Issued at 303 PM CDT Mon Jul 3 2023
Key Messages:
- Heat, with very warm temperatures will probably be the main
story for the next two days. Some small storm chances exist
tonight mainly west and north of La Crosse.
- The higher chances of storms to affect the July 4th evening
fireworks are found from northcentral WI into southeast MN.
Roughly Medford WI to Rochester and Austin MN and west. A
severe storm is possible.
- A pattern change brings seasonally cooler air into the area
Wednesday which could persist for some time.
Late This Afternoon into Tonight
Currently watching storms firing along a convergent boundary near
the Minnesota and Iowa border. The 06.12Z WRF ARW is the only CAM
which is currently capturing this convection. It shows that that
this convection will continue to move east toward our area and
then it dissipates as it moves east of Interstate 35.
As the shortwave trough, currently from the MN arrowhead to swrn
MN, moves off to the northeast from this evening into tonight,
the 03.18Z RAP shows the best 925 mb and 850 mb moisture
convergence shifts off to the north and northeast. This results in
the better storm chances from north-central Iowa, northeast
through sern Minnesota, and into north-central Wisconsin. This
matches the ARW outcome well for this evening. Elsewhere, there
is plenty of instability above the cap, the issue is there does
not appear to be much forcing to release this instability. As a
result, kept these areas mainly dry for tonight.
Tuesday July 4th Heat and Storms
On Tuesday, the cold front will gradually work east toward the area.
Increased southerly winds ahead of this front will result 925 mb
temperatures warming into the 24 to 26C range. Still looking like
much of the afternoon will be partly to mostly sunny. In addition,
dry soils will allow for some additional warming. This will result
in the potential for the high temperatures to warm above guidance.
This is especially the case in the river valleys. With the MAV MOS
temperature guidance continuing to perform better /but a high
outlier/ than the NAM MOS, trended the high temperatures (mid-80s
to upper 90s) toward it. With dew points remaining in the lower
to mid-60s, heat indices will only be a few degrees higher than
the air temperature. Will keep messaging heat for awareness.
With weak forcing located over much of the area, the CAMs continue
to struggle on the location of the showers and storms. With the
better forcing being located from northeast Iowa northeast into
north-central Wisconsin, kept the highest rain chances (30-50%)
going there during the day. HREF continues to indicate that the
CAPE average will be around 1500 J/kg. With the 0-6 km shear
generally less than 20 knots, there will be not much shear to help
organize the convection, so any severe weather looks to be
isolated. The HREF continues to indicate the highest threat for
damaging winds will remain northwest of the area. However, with
soundings showing an inverted V below the cloud layer, there will
still be the possibility of damaging winds if storms are able to
develop.
July 4th Night and Wednesday....
As the front approaches the area in the early evening, storms are
expected to be fairly widespread along it from northwest WI to
northcentral IA shifting east. SPC 03.12Z HREF suggests CAPE
rapidly decreases in the evening over the area and with weak wind
shear profiles, some decrease in coverage is expected as the
storms head east. Certainly, their intensity will wane. However,
some low severe storm probability exists through the early evening
west and north of La Crosse, with probabilities increasing in
that direction. Currently have rain chances of 70%+ across the
entire area Tuesday night into Wednesday morning, but have some
doubts as to whether this is too high with waning instability.
The front will be located in WI on Wednesday and some shower or
storm activity is likely to be ongoing during the morning hours.
There is some spread on the front location by noon which will be
key to afternoon storm chances. Highest storm development scenario
is a slower timing where destabilization occurs from central into
swrn WI and an increase in coverage of storms occurs. With weak
wind shear in place, there may be an isolated severe storm chance
before the front scours southeast ending the threat. This timing
will be refined in the next day or so.
Pattern Shifts To Cooler...Wednesday Night Through Monday
The cold front moving east of the area Wednesday afternoon begins
the transition of the large scale pattern over the northcentral
U.S. to be one dominated by large scale troughing. This feature
seems to persist possibly into mid-July. During the late week and
into next week, "gentle troughing" dominates the pattern with
slightly below normal temperatures and humidity. Comfortable and
dry weather is expected late week. By the weekend, agreement is
good on the general idea of a more vigorous shortwave trough
moving through the area, but differences in timing, strength, and
track are seen.
Mid-range precipitation chances are suggested later Saturday for
sern MN and nern IA for the faster solutions (25% of the ensembles),
while a larger batch of members hold it off until Sunday (37%).
Consensus in the GEFS/EPS/Canadian ensembles keep the instability
(SBCAPE >500 J/Kg) to the south of the area but do show good
moisture return into the system. While it seems to favor the south
at this time, moisture transport looks favorable for some
elevated rain chances with the system. But, the spread in timing
and placement are of such lower confidence that only lower chances
of rain (30-40%) are seen in the blend, slightly favoring south
of I-90 closer to the moisture inflow. Right now, its tough to say
when and where to improve on that forecast.
&&
.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 1055 PM CDT Mon Jul 3 2023
Current convective activity is expected to be past both airports
by the time the new forecasts start so do not plan to include a
mention of showers/storms. Conditions should quickly return to VFR
behind the convection and remain that way through Tuesday. More
showers and storms look to be possible Tuesday evening as a cold
front approaches from the west. Forcing for the storm development
looks a little disorganized for have only included a VCSH for KRST
for now.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
DISCUSSION...Boyne/Baumgardt
AVIATION...04
Area Forecast Discussion
National Weather Service Columbia SC
805 PM EDT Mon Jul 3 2023
.SYNOPSIS...
Expect hot and humid conditions again Tuesday, with a chance of
mainly afternoon and evening thunderstorms. Temperatures are
expected to trend back down to near normal values, with a good
chance of mainly afternoon and evening thunderstorms, mid week into
next weekend.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
Relatively warm mid levels have generally suppressed convection
over the forecast area. Outflow boundaries from the sea breeze
and from upstream may spark thunderstorm development this
evening. However with loss of daytime heating and the set up of
the nocturnal inversion there may not be enough instability for
widespread convection. The HRRR depicts minimal convective
coverage over central SC and the CSRA, increasing confidence in
an isolated to widely scattered forecast. Any isolated storms
may linger through the overnight but are not expected to pose a
threat of severe weather. Convective debris clouds and a moist
airmass will keep lows tonight in the mid 70s.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
Weak upper troughiness will shift across the region through the
period, with atmospheric moisture progged to remain high. A
weak surface boundary will shift into the region. Diurnal
heating expected to result in good chances of afternoon and
evening thunderstorms. SPC maintains a MRGL risk of severe
storms each day due to considerable instability projected, along
with high LFC heights and fairly deep low level inverted-V
feature on forecast soundings. Latest guidance suggests
generally mid 90s for highs Tuesday, with afternoon dewpoints in
the lower 70s, possibly mid 70s. This brings max heat index
projections to just below our local Heat Advisory criteria of
110F. Highs expected to trend down some Tuesday. WPC also
maintains MRGL risk of excessive rainfall in any training or
merging cells due to high atmospheric moisture content.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
Fairly typical summerlike weather expected, albeit a little
higher than normal chances of diurnal convection. Weak upper
troughiness and high atmospheric moisture remains in place
through the period, with another weak surface boundary entering
the region. Guidance indicates near normal temps and good chance
POPs. WPC maintains MRGL risk of excessive rainfall Thu/Fri.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
VFR through the TAF period. SCT cumulus dissipating heading into
the overnight period with high level debris clouds from
dissipating convection to our west overspreading the area.
Slight chance of a shower or thunderstorm through late this
evening, but confidence is low for impacts at the terminals. SFC
winds WLY/SWLY 5-8 kts becoming light and variable overnight.
Low confidence in VSBY restrictions Tuesday morning. Winds
Tuesday increasing late morning WLY 5 to 10 kts. Showers and
thunderstorms possible Tuesday afternoon.
EXTENDED AVIATION OUTLOOK...Brief restrictions are possible
daily through Saturday from passing showers and thunderstorms,
mainly during the afternoon and evening hours. Hazy conditions
and areas of patchy early morning fog are also possible each
day.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
&&
$$
Area Forecast Discussion
National Weather Service Cheyenne WY
948 PM MDT Mon Jul 3 2023
.SHORT TERM...(Rest of Today through Tuesday)
Issued at 237 PM MDT Mon Jul 3 2023
Key Impact Messages:
1) Thunderstorms beginning to develop and move into western Carbon
county. Strong to severe thunderstorms may impact parts of
northern Converse, Niobrara and northern Sioux and Dawes counties
this evening. Large and damaging winds will be main the hazards.
2) Another round of severe weather is expected across SE Wyoming
tomorrow afternoon. All modes of severe weather will be possible
in addition to heavy repeated rainfall.
Weather Overview: Surface analysis shows the cold front is snagged
up over the SD/NE/WY borders. South of this boundary temperatures
have climbed into the 90s across much of the Nebraska Panhandle
and into the 80s across much of eastern Wyoming. This boundary
will be the focus of tonights convection across northern Wyoming
and the north Nebraska Panhandle. Satellite shows much of the warm
sector devoid of clouds with only a few CU fields showing up close
to frontal boundary and over the higher terrain out across Albany
and Carbon counties. A few stronger updraft towers are beginning
to move into western Carbon county with a few lightning strikes
showing up. Isolated to scattered thunderstorms should continue
across Carbon county through the afternoon hours. The attention
will turn to more organized convective activity later this evening
where severe weather can be expected.
Discussion: Synoptic setup regarding the severe weather potential
across SE Wyoming and the Nebraska Panhandle on Tuesday remains on
track but will still depend on the arrival of the southward
moving frontal boundary and how far south it pushes or where the
frontal boundary becomes stalled out. The leeside trough remains
on track which will keep a consistent northeast to easterly flow
which will push dewpoints into the 50s across SE Wyoming and
approach the 60F mark for parts of the Nebraska Panhandle. HI-RES
and CAM models have been in agreement in the overall initiation
point and evolution of the convection tomorrow with most storms
firing over the higher terrain across southern Albany county and
moving east into Laramie county as pseudo discrete supercells
with a few storm clusters pushing into the Nebraska Panhandle. The
HRRR and NAM NEST has been consistent in showing a few weak UH
tracks across Laramie county tomorrow near Cheyenne. The Storm
Prediction Center continues to advertise for a Slight Risk across
much SE Wyoming tomorrow afternoon.
.LONG TERM...(Tuesday night through Monday)
Issued at 237 PM MDT Mon Jul 3 2023
Minimal changes to the long term forecast. Near daily chances for
showers and thunderstorms of various strength. Wednesday is forecast
to be very cool compared to normal, highs in the 60s to low 70s.
Temperatures could even potentially be cooler, but did not have the
confidence to decrease it too much more. Main instability stays
along or just east of the Laramie Range, so there is a chance, if
the skies can clear, for some showers and thunderstorms. Thursday a
shortwave passage, in conjunction with much stronger instability and
dewpoints in the 50s, creates a decent set up for strong to severe
thunderstorms. SPC is continuing to show a 15% chance for severe
thunderstorms across the High Plains.
After Thursday, southeast Wyoming and the Nebraska panhandle stays
on the northern end of an upper level ridge with a train of
shortwaves continually ejecting eastward across the area. With the
upper level ridge in place, temperatures rebound back closer to
normal: Highs in the 70s to 80s and lows in the 40s to 50s.
&&
.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 947 PM MDT Mon Jul 3 2023
Wyoming TAFS...A cold front moving from north to south will pass
across the terminals after daybreak on Tuesday, with isolated to
scattered showers and thunderstorms along with lowering visibilities
and ceilings at Laramie and Cheyenne. Broken ceilings from 10000 to
12000 feet AGL will prevail tonight, with ceilings lowering to 4000
to 8000 feet AGL Tuesday afternoon with thunderstorms in the
vicinity of the terminals. Widespread showers will prevail Tuesday
evening with visibilities lowering to 2 miles and ceilings lowering
to 1500 to 2500 feet AGL at Laramie and Cheyenne, with broken
ceilings near 4000 feet at Rawlins. Winds will gust up to 25
knots outside of thunderstorms.
Nebraska TAFS...A cold front moving from north to south will pass
across the terminals Tuesday morning with winds becoming north and
gusting up to 25 knots. Isolated thunderstorms will end at Chadron
and Alliance by 08Z. Otherwise, expect ceilings from 9000 to 12000
feet AGL overnight, with ceilings lowering to 4500 to 6000 feet AGL
Tuesday afternoon and then to 2500 to 3500 feet AGL Tuesday evening.
Expect occasional thunderstorms reducing visibilities to 4 miles at
Sidney from 00Z to 03Z Tuesday evening.
&&
.FIRE WEATHER...
Issued at 213 PM MDT Mon Jul 3 2023
Some pockets of elevated fire concerns today will be possible
across Albany and Carbon counties. Gusty westerly winds and RH
values dropping to around 15% will be common before isolated
thunderstorms begin to move into the areas. Across the rest of the
region, minimal fire weather concerns can be expected. Chances for
wetting rains will be possible Tuesday and again on Thursday.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...None.
NE...None.
&&
$$
SHORT TERM...AW
LONG TERM...LG
AVIATION...RUBIN
FIRE WEATHER...AW
AREA FORECAST DISCUSSION
National Weather Service Kansas City/Pleasant Hill MO
613 PM CDT Mon Jul 3 2023
...Updated 00Z Aviation...
.Discussion...
Issued at 403 PM CDT MON JUL 3 2023
Key Messages:
- Warm and Humid Afternoon Independence Day
- Showers/Storms Late Tuesday Overnight into Wednesday
- More Shower/Storm Development Possible Wednesday
Discussion:
Mid-level flow is rather weak across much of the Central CONUS with
a surface high pressure sitting over the mid-Mississippi Valley. A
weak short-wave perturbation has generated some weak
shower/thunderstorm activity over Oklahoma and has pushed extra
moisture in southern Missouri. A few showers have popped up along
the Interstate 44 corridor this afternoon. Our area though while
seeing developing clouds likely has remained dry with the surface
high pressure sliding down drier air, and thus has kept any shower
activity limited. Have placed slight chance POPs in our far
southwest to line up with the area of weak showers in northeast
Oklahoma that may clip our southwest. Overall, there will not be
much forcing for this afternoon. Cumulus clouds should dissipate
shortly after sunset.
A 500mb closed-low over the Saskatchewan-Manitoba border has
resulted in broad cyclonic flow across much of the Northern Plains.
While center of this system stays well north of the area, this is
expected to eject a few short-waves across region through the middle
part of this week. Overnight, a short-wave axis over the Northern
Rockies induces localized vort max into the Colorado Front Range and
Central High Plains. A surface lee cyclone is progged to develop in
response to this extended short-wave trough, and across the Plains
into the mid-Mississippi River Valley provides southerly return flow
near the surface. This will result in a strong theta-e advection
regime that should send temperatures into the lower to mid 90s
across the area, with dewpoints back into the upper 60s. Through the
afternoon, expecting modest H5 height rises in response to the WAA
max between 850-700mb. Weak isentropic likely provides increasing
cloud cover through the afternoon hours. Surface trough extends
across the region late into the afternoon, and perhaps a few showers
develop along the axis of pre-frontal surface troughing. With weak
flow, storm-relative flow will also be weak for warm sector
updrafts, thus most updrafts while they could reach a decent depth
are likely to remain narrow and experience deleterious effects from
entrainment, especially with dry air between 700-500mb. The H5 vort
max though remains along the KS-NE border for most of the afternoon
well west of the area, meaning there is little deep layer shear
across the warm-sector and little in the way of forcing. This will
lead to a warm and muggy day across Missouri and eastern Kansas.
Attention turns to a cold front coming out of the Nebraska Sandhills
in mid-afternoon that trails the developing surface low. By late
afternoon, the vort max finally reaches closer to the area and we
begin to see stronger H5 height falls, and perhaps more isolated
shower activity is able to get going. Even with the strengthening
height falls, most of the better flow is behind the cold front. So
while the ambient warm sector will be well mixed with nearly dry-
adiabatic lapse rates in the boundary layer, and 7.5 to 8.0 C/km
lapse rates in the mid-levels, forcing will be difficult to come by.
Satellite imagery may show an agitated cumulus field and maybe a few
orphan anvils. More robust thunderstorm activity first develops over
Central Nebraska and North-Central Kansas late afternoon along and
ahead of the cold front where strong flow will be located.
Eventually these storms congeal and develop a stronger QLCS. This
QLCS propagates into the northeast Kansas, and eventually reaches
our forecast very late in the evening on Tuesday. CAMs, while
showing variations in intensity of the QLCS, are in decent agreement
of an arrival after 03z, with the bulk of it moving through the
forecast area after 06z. The dissipation of the QLCS is being
handled differently by current CAM solutions though. The HRRR has
been bringing the system through the KC metro and ends the heavier
activity east of the Interstate 35 corridor. HiRes-ARW is similar.
The NSSL-WRF and NAM-Nest has the QLCS breaking apart as it crosses
into Missouri. How far east it travels will likely depend on cold
pool behavior with the system. There will be a a potent warm-sector
ahead of it to draw in more energy as it develops, with MLCAPE
values between 2000 and 3000 J/kg and MUCAPE between 3000 and 3500
J/kg. While the wind shear is weak across most of the warm-sector
late Tuesday Night into Wednesday, it does drastically increase in
close proximity to the cold front. 0-6km bulk shear values will
increase to about 35-40 kts directly in front of the front, and 0-
8km values around 50 kts. This should allow for a decent amount of
time for cold pool vorticity to achieve balance with environmental
vorticity. With theta-e deficits near 20-25C between the surface and
the top of the boundary layer, would anticipate cold pools to very
strong. Therefore, presenting a damaging wind threat, could perhaps
see portions of the line exceed 70 MPH. While 0-3km bulk shear
values will be around 30-40 kts along the line, the vector is
oriented mainly from the southwest, parallel to the QLCS. Therefore,
mesovortex generation will be hard to achieve, especially for our
forecast area. A drastic rear-inflow jet would be needed to create a
surge to reorient the vector favorably. A few pockets of brief hail
cores are possible given the robust lapse-rates which will lead to
stronger updrafts. But given how warm surface temperatures will be
and overall higher freezing levels, do not see hailstones hanging
out in the hail embryo growth zone for long enough. A better chance
for hail would actually be with multi-cells that develop over the
warm sector but ahead of the main cold front and QLCS. But as
previously mentioned, updrafts will have weak relative flows. Thus,
the main severe threat with late Tuesday night into Wednesday
morning will be winds.
Wednesday, the cold front will likely be in the east and southeast
portions of the CWA. Additional shower and thunderstorm development
may be possible. This will be highly dependent on where convection
dissipates from the first round that enters Tuesday Night. Remnant
outflow boundaries could also very well play a role in the position
of new convection initiation Wednesday afternoon. Multicell clusters
could present additional damaging wind gusts and hail around 1 to
1.5 inches in diameter. Wind shear should be stronger on Wednesday
morning into afternoon, which could help for more organization.
However, if the cold front completely clears the area, or the
previous morning`s QLCS moves through faster and stabilizes the
boundary layer, Wednesday may not see much action at least in our
forecast area, and becomes more of an event for southeast Missouri
and into the Ohio River Valley. Differential heating with the cold
and any nearby outflows will greatly influence the mesoscale
environment, and this far out is hard to speculate the most likely
outcome. Temperatures on the backside of the cold front should be
cooler Wednesday, and keeps the latter portion of the work week in
the in the lower to mid 80s across the forecast area.
A quick note on hydrology and QPF. Overall confidence is high in the
occurrence of accumulating precipitation along the cold front Tuesday
Night into Wednesday morning. Most of the forecast area holds around
50 percent chance to see at least one-quarter of an inch of
rainfall. Heaviest rainfall though within the QLCS appears to be
favored more in northeast Kansas. There, the 12z HREF probability
matched-mean show pockets of 1 to 2 inches, while in Missouri these
values are between 0.5 to 1 inches. If the cold front stalls
overnight, this may be able to produce locally higher amounts. While
some relief to drought conditions will be brought, the current
progged QPF does not appear to be a drought buster. However, more
activity later into the week may help some. As for flooding, the
antecedent dry conditions will keep the flood risk minimal. With
the ground being very dry, a heavier downpour could result in some
rapid run-off before it is able to start absorbing again. Perhaps
localized areas of flooding could become possible, but overall, the
flash flooding concerns will be very minimal with the Tuesday-
Wednesday event across the area.
Toward the end of the week, long range guidance depicts a ridge
developing along the Gulf Coast with the axis extending into the
southern Ozarks. There also several short-wave perturbations through
north of the ridge axis that extend from persistent cyclonic flow
over Canada which will present additional chances for rain showers
and thunderstorms. Given it will be in the on the edge of a dome of
warm-moist gulf air, would expect several round of isolated to
scattered activity potentially through the weekend. The potential
organized activity will depend on how strong the vort maxes develop
and what kind of wind shear they will be able to provide.
&&
.Aviation...(For the 00Z TAFS through 00Z Tuesday Evening)
Issued at 613 PM CDT MON JUL 3 2023
VFR conditions are very likely through the forecast period. Clear
skies to a few high-level clouds expected through the evening and
overnight hours. Tomorrow, only a few diurnal CU possible with
bases at or above 5000 feet. Winds will be light through the
forecast but shift to the south-southeast during the day tomorrow.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
Discussion...Krull
Aviation...CDB
Area Forecast Discussion...UPDATED
National Weather Service Austin/San Antonio TX
652 PM CDT Mon Jul 3 2023
...New UPDATE, AVIATION...
.UPDATE...
Issued at 652 PM CDT Mon Jul 3 2023
An earlier update was done to increase PoPs slightly through the
evening hours, and expand mention of isolated showers and
thunderstorms into the I-35 corridor as well as portions of the Rio
Grande. Activity across the Coastal Plains, Brush Country, and Mexico
will continue working west and north through sunset. A gradually
decrease in activity is expected after sunset.
&&
.SHORT TERM...
(Tonight through Tuesday night)
Issued at 233 PM CDT Mon Jul 3 2023
Visible satellite images are showing partly cloudy to mostly cloudy
skies across South Central Texas as of early this afternoon. This
trend is forecast to continue through this evening into the Tuesday
morning period. Daytime temperatures are expected to reach the mid
to upper 90s with some locations over the southern Edwards Plateau
in the low 90s. Can`t rule an isolated shower or even a thunderstorm
or two to develop across the Hill Country and areas along and east
of Highway 77 later this afternoon and early evening. If any storm
develops, can`t rule out a quick heavy downpour associated with it
with pwats in the 1.7 to 1.9 range based on RAP and NAM forecast
soundings.
Looking out to the west over the northeast part of Mexico, isolated
storms are ongoing as of 2 pm with weather guidance keeping the
activity into the evening. Several hires suggest for this activity
to have some sort of minor impact across the Rio Grande this
evening. Therefore, decided to go with a 10 to 20 percent for
showers/storms. Also, later this evening, a shower or two could pop
across the Hill Country according to hires weather solutions in
relation to local effects or a passing boundary. Otherwise, the
overnight period is forecast to be relatively quiet with lows in the
70s.
The Fourth of July starts with lots of clouds across the local area
with clouds breaking into the afternoon period. Highs are forecast
to range from the low to upper 90s across most areas and up to 104
degrees across a few spots over the Rio Grande. The day looks to be
dry, hot and humid with isolated showers and thunderstorms possible
across the coastal plains from the mid to late afternoon. Heat index
values are expected to be elevated and ranging from 103 to 107 east
of Interstate 35. Partly cloudy skies are anticipated for the Fourth
of July evening celebrations with temperatures in the mid 80s to low
90s. Increasing clouds are forecast for late Tuesday night
especially across the coastal plains with overnight lows in the 70s.
&&
.LONG TERM...
(Wednesday through Monday)
Issued at 233 PM CDT Mon Jul 3 2023
A continued broad weakness within the 500 mb pattern aloft and the
advection of higher gulf low-level moisture from the south-southeast
should help to promote rain and storm chances for areas around and
east of I-35 during Wednesday afternoon with the inland progression
of the seabreeze. Thursday then looks to offer the greater chances
and areal coverage for activity with the help from possible outflow
coming off a stalled front to our north and again the seabreeze. The
rain chances then peter out by the weekend and into next week as the
mid-level ridging across the Desert Southwest builds eastward and
eventually amplifies.
The heat will become the main story and greatest concern again for
the long term, especially from the weekend into early next week. On
Wednesday and Thursday afternoon, high temperatures are to stay in
the mid to upper 90s for the majority but given increased low-level
moisture coming off the gulf, dew points stay elevated where peak
heat indices during the afternoon could flirt around or even exceed
Heat Advisory criteria across portions of the region, specifically
the Coastal Plains. As the mid-level ridge then starts to build in
from the west by the weekend into next week, Heat Advisories become
even more likely as temperatures climb day by day with afternoon
highs reaching into the 100s across more locations and heat index
values into the 108 to 112 for some areas. Please continue to take
precautions against heat exhaustion and heat stroke as we head into
this next heatwave. Overnights will also stay very warm and humid
with overnight lows mainly in the 70s and perhaps the low 80s at
times for some locations.
&&
.AVIATION...
(00Z TAFS)
Issued at 652 PM CDT Mon Jul 3 2023
Isolated SHRA/TSRA activity ongoing across South Central Texas. This
will approach AUS/SAT/SSF 00Z-03Z, and could possibly impact these
TAF sites. Activity is expected to gradually weaken and eventually
dissipate 02Z-04Z. Otherwise, VFR conditions are expected across most
of the area through the TAF period, with the exception of a corridor
of MVFR ceilings possible around 11Z-14Z near and east of SAT.
&&
.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry 78 98 79 98 / 20 10 0 20
Austin Bergstrom Intl Airport 76 96 78 96 / 20 10 0 20
New Braunfels Muni Airport 76 97 78 96 / 20 10 0 20
Burnet Muni Airport 76 95 76 96 / 10 10 0 10
Del Rio Intl Airport 78 96 79 99 / 10 10 0 0
Georgetown Muni Airport 77 96 76 97 / 20 10 0 10
Hondo Muni Airport 75 96 76 97 / 10 0 0 10
San Marcos Muni Airport 76 96 77 96 / 20 10 0 20
La Grange - Fayette Regional 77 96 78 95 / 20 20 0 30
San Antonio Intl Airport 77 97 79 97 / 10 0 0 20
Stinson Muni Airport 78 98 79 98 / 10 10 0 20
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Short-Term...76
Long-Term...Brady
Aviation...76
Area Forecast Discussion
National Weather Service Gray ME
1138 PM EDT Mon Jul 3 2023
.SYNOPSIS...
Showery weather continues through mid-week as upper level
disturbances gradually cross New England. Embedded thunderstorms
and downpours remain the primary focus with this activity.
Drier and warmer weather builds into the region Wednesday
through Friday, however showers cannot be entirely ruled out as
humid conditions persist. The reprieve is brief, with rain and
thunderstorm chances increasing again this weekend.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
1138 PM Update...A stationary front south of the NH/MA border
has provided a focus for showers with embedded thunder across
southern New England and some of this activity has shifted into
southwest NH. A storm in southeast Cheshire County has produced
rainfall rates greater than 3 inches per hour and has exhibited
backbuilding prompting a Flash Flood warning. Recent runs of the
HRRR has not captured this storm well. Latest RAP analysis
still shows between 500-1000 J/kg of MUCAPE across southern NH
into interior western Maine. Additional showers have blossomed
just SE of the White Mountains and recent runs of the HRRR has
been targeting Carrol County into SW Maine where additional
activity will develop over the coming hours. This is a secondary
area of concern for issuing potential short fused flood
products. Have mainly adjusted PoPs and QPF to account for these
trends and will be closely watching portions of southern NH
into SW Maine for slow moving heavy showers with embedded
thunder.
751 PM Update... No significant changes to the going forecast
for the rest of tonight. Showers and a few instances of
lightning are ongoing across northern NH into the western
mountains of Maine. These showers and isolated thunderstorms
have been relatively small and moving along and/or dissipating
that rainfall amounts have stayed well below FFG. Hi res
guidance has these showers drifting southeast through this
evening and weakening as they do so. Overall concern for strong
storms and flash flooding is low and will further diminish
this evening with the loss of instability. There will be another
wave of showers and embedded thunder moving along a boundary to
our south that are projected to push into southern NH after
midnight and have mainly refined PoPs to capture this and recent
radar trends.
ORIGINAL DISCUSSION...
Scattered showers will continue this evening with an isolated
rumble of thunder per latest HRRR solution as convection
continues to gradually build over western sections. A storm with
gusty winds in New Hampshire is possible. Showers will also continue
to have the possibility of dropping heavy rainfall in a short
period of time.
Fog will redevelop and it will be muggy. This will allow
temperatures to remain in the 60s for overnight lows tonight.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
Morning fog will be persistent across the region, especially
southern Maine. Fog should burn off/mix out by most area
holiday parades.
An examination of our multi day bout of locally heavy rainfall
indicated the HREF has been outperforming other guidance.
Leaning towards this model solution relatively closely for
Tuesday with showers and scattered thunderstorms redevelop over
the region as an upper level trough remains over the region.
Other guidance also suggests heavy showers may cross relatively
slowly through southern New Hampshire and have therefore placed
this region in an area of locally heavy precipitation as we
remain in a marginal risk for excessive rainfall in the latest
WPC outlook. Persistent and multi rounds of heavy showers may
lead to localized flooding. Another potential area to watch
would be the higher terrain in the mountains as the slow movers
may become concentrated in that location. Bufkit profiles do
suggest some slow movers in the region with precipitable water
values topping out at two inches in our fully saturated
atmosphere.
It will be slightly warmer and continued humid. There will be
breaks in the cloud cover allowing readings to climb through the
70s in most areas with some 80 degree readings inland.
The convection winds down Tuesday night, however there could be
a shower or a rumble of thunder in the evening. Fog will
develop once again. This brings us to a warmer and slightly
drier focus in the extended portion of the forecast.
Tides: Storm tides remain close to a foot above normal this
afternoon. Tides will run high tonight and Tuesday night
approaching flood stage. However, there will be little wind and
wave action. Have opted to issued a Coastal Flood Statement for
tonight`s high tide.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
Overview: Continued warming trend across the southern interior
and higher chances of showers/storms Wed as mentioned by
midnight crew. Should be noted that the region does fall out of
Marginal ERO forecasts by WPC Wed-Fri as PWAT values decrease
and stronger forcing vacates the region. Widespread rain
chances increase more by Friday into the weekend as a cold
front moves towards the region.
Details: Ridge lifting across the eastern Great Lakes will work
to funnel in drier air aloft into northern New England. This
will also allow lapse rates to increase with cooler air aloft.
However, the lack of a stronger forcing agent and the more
shallow moisture will keep thunder coverage limited Wednesday
afternoon.
Amid mainly stagnant low level flow, do expect sea breeze to
make its way inland during the mid afternoon. This will likely
act as a lifting mechanism to concentrate convergence across the
interior of Maine and the NH Lakes Region. While this may help
to initiate, the cooler marine air will also hurt storm health
once ingested. Outside of less moisture and only a brief period
of deeper shear, storm parameter space looks good for isolated
stronger cells that could produce heavy downpours, small hail,
or some gusty winds should they collapse. Again, coverage will
be isolated to perhaps a handful of these stronger storms that
could take advantage of up to 1500 j/kg of CAPE and 35kt of
0-6km bulk shear. Low level lapse rates will support towers to
quickly generate mild updrafts, but may reach a limit as mid
level lapse rates look to hover around 6 c/km or just below.
Lot of short term, hires guidance runs to go through before
then and now, so will move on to other long term trends. For
temperatures during the period, warmer weather peaks during the
Wed-Fri time period. In particular will be days cloud breaks
allow sun to make good progress on heating the surface. This may
be diluted somewhat should marine air make inroads and bring
stratus overhead during morning periods. At this time, more
confident in that occurring Wed through the Midcoast and central
ME amid other cu developing. Warmest values Wed-Fri look to be
across the southern half of NH where upper 80s and around 90
will be possible. Valleys and coastal locations likely see
typical fog cycle with potentially decreased vis overnight and
slow improvement thru morning.
The arrival of a cold front late week into the weekend will
again trend temps down along with the aforementioned increased
rain chances. This will also increase chances of a stronger
storm to the region, but details of this will improve with time.
&&
.AVIATION /04Z TUESDAY THROUGH SATURDAY/...
Short Term...Areas of IFR and LIFR conditions develop once again
tonight in low clouds and fog, especially along and near the
coastline. Low chance showers are possible. These conditions
persist early Tuesday morning before slowly improving. Showers
and isolated thunderstorms will develop during the day with
localized IFR conditions. Low clouds and fog persist Tuesday
night.
Long Term...Wed morning IFR possible along the ME coast and
waters will give way to VFR. SHRA possible TS for AUG/RKD/LEW
region Wed afternoon. Patchy fog may bring IFR to LIFR vis
overnight into Thurs morning. Additional SHRA chances towards
the mountains Thursday. Ceilings then will trend down ahead of a
cold front Friday into Saturday.
&&
.MARINE...
Short Term...Winds and seas will remain below SCA thresholds
tonight through Tuesday night. However, areas of fog will
persist, mainly during the overnight periods. This will lead to
locally low visibilities on the waters.
Long Term...Conditions likely remain below SCA, although period
of marine fog are likely amid week flow and high pressure near
the waters.
&&
.HYDROLOGY...
Wet conditions continue across the region with portions of
southeast New Hampshire and far southwesternmost Maine receiving
2 to 4 inches of rain Sunday into early Monday. Flash flood
guidance remains very low across the region. Areas of slow
moving convection will need to be closely monitored, especially
over the higher terrain and southern New Hampshire Tuesday
afternoon. A river flood warning for the Suncook River at North
Chichester remains in effect.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...None.
NH...None.
MARINE...None.
&&
$$
UPDATE...Schroeter
NEAR TERM...Cannon
SHORT TERM...Cannon
LONG TERM...Cornwell
Area Forecast Discussion
National Weather Service Houston/Galveston TX
617 PM CDT Mon Jul 3 2023
...New AVIATION...
.SHORT TERM...
(This evening through Tuesday Night)
Issued at 328 PM CDT Mon Jul 3 2023
Hot and humid with growing cumulus is the theme this afternoon.
Temps are generally in the mid-90s with heat index values over
100F. Some of you will likely receive a cooling shower or
thunderstorm this afternoon. If satellite and radar trends have
anything to say about it, the best chance of afternoon showers and
storms will be associated with the sea breeze boundary that has
already sparked off a few showers/storms over our coastal
counties. Locally heavy rainfall, gusty winds, and lightning will
be the primary concern. Not every locations will receive rain.
Chance of storms will decrease with the loss of daytime heating.
Expect another very warm and muggy night.
At first glance, the 4th of July looks like a carbon copy of
today. Once again it will be quite hot and humid. Remember to
practice heat safety if you are spending your holiday outdoors.
However, a closer look at the atmosphere and the model guidance
show that PWAT values are likely to be on the increase as a
gradual surge of deep tropical moisture pushes northwestward from
the western Gulf of Mexico into southeastern Texas. RAP analysis
is currently showing PWAT values of 1.60-1.80" across our CWA.
PWATs could increase to at least 2.00" by tomorrow afternoon,
adding more fuel for shower and thunderstorm activity. Therefore,
we think PoPs are generally higher tomorrow than they are today.
Our PoPs skew a little higher than NBM guidance since moisture is
expected to be quite abundant. PoPs range from 20-30 percent in
our northern most and Brazos Valley Counties to 40-60 percent in
the Houston metro. The bay area along with coastal Brazoria,
Galveston, and Chambers all have PoPs near 60 percent. Coastal
areas could have shower and thunderstorm activity as early as the
mid morning hours. Otherwise, the best chance of showers and
thunderstorms will be from about midday through the afternoon.
Much like today, PoPs should decrease with the loss of daytime
heating. Though the chance of rain isn`t necessarily zero after
sunset, the chance of shower and thunderstorm activity occurring
during peak firework display time is relatively low. But it`s
never a bad idea to check the radar just in case!
Happy 4th of July everyone! Be safe and enjoy!
Self
&&
.LONG TERM...
(Wednesday through next Sunday)
Issued at 328 PM CDT Mon Jul 3 2023
Rain and thunderstorm chances are the main weather story in the long
term period. A weak upper trough will continue through the week,
setting up the stage for a more typically summer- like pattern. At
the surface, high pressure centered over the eastern Gulf will
continue to bring persistent onshore flow, and hence, deeper Gulf
moisture over the area. In fact, deterministic models, including
NAM, suggest an uptick in moisture with PWAT values at or above 2
inches through the end of the week. The combination of deep
moisture, multiple vort maxes aloft and diurnal cycle convection
(sea/bay breeze interaction) will allow for increasing rain and
storm chances each day. A parameter to continue monitoring is sfc
dewpoints, especially in the afternoon hours. Latest guidance,
particularly the GFS, suggest dewpoints in the upper 60s to low
70s Wednesday afternoon across our half western counties.
Therefore, the best chances look to remain south of I-10 and over
the Gulf waters. Rain and storm chances will gradually decrease
after Saturday as upper ridge centered to our west strengthens and
moves overhead.
Temperatures-wise...increasing cloud cover and precipitation
chances will keep temperatures near to slightly above normal.
Highs will generally be from the low to mid 90s. Overnight lows
mainly in the mid to upper 70s. A gradual warming trend is once
again expected during the weekend as the ridge builds over the
region. Highs from the upper 90s to even 100F can be expected
Saturday and Sunday. Increasing humidity and hot conditions will
likely bring heat indices near advisory levels during this time
frame.
JM
&&
.AVIATION...
(00Z TAF Issuance)
Issued at 617 PM CDT Mon Jul 3 2023
Most thunderstorms currently safely outside all 10 nm circles, but
a cell 8-10 nm SW of IAH may manage to produce a couple strikes
before dying out shortly after the forecast period opens.
Otherwise, look for winds and storms to drop off after sunset.
Some guidance suggests patchy fog and/or IFR CIGs for a couple
hours pre-dawn, but not enough confidence to go more than MVFR
CIGs right now. Thunderstorm coverage tomorrow should be broader
than today, but not enough confidence to do more than sketch out a
broad VCTS window, and leave the specifics to future forecast
cycles.
&&
.MARINE...
Issued at 328 PM CDT Mon Jul 3 2023
Surface high pressure centered across the eastern Gulf will continue
to bring light to moderate onshore flow along the Upper TX coast.
Winds will generally remain between 10 to 15 knots through mid-week,
before increasing towards the end of the week. Isolated to
scattered showers and thunderstorms are expected each day this
week. The best chances will be at night into the early morning
hours over the Gulf waters and along the coast and Bays in the
afternoon and evening. The best potential for rain/storm chances
will be Wednesday through Friday. Drier and warmer weather returns
late Saturday/Sunday. With persistent onshore flow, the risk of
rip current will increase after Wednesday.
JM
&&
.PRELIMINARY POINT TEMPS/POPS...
College Station (CLL) 77 96 77 96 / 20 20 10 30
Houston (IAH) 80 95 79 94 / 10 40 10 50
Galveston (GLS) 82 89 82 89 / 20 40 20 60
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...None.
GM...None.
&&
$$
SHORT TERM...Self
LONG TERM....JM
AVIATION...Luchs
MARINE...JM
Area Forecast Discussion...UPDATED
National Weather Service Jackson MS
909 PM CDT Mon Jul 3 2023
...New MESOSCALE UPDATE...
.MESOSCALE UPDATE...
Issued at 909 PM CDT Mon Jul 3 2023
We have reached the familiar part of the day where convective
coverage is generally decreasing with the loss of diurnal
heating. However, scattered convection is festering, mainly across
portions of south MS and along the AL state line. Once again there
will be potential for isolated to scattered convection to persist
through the night given the corridor of rich deep moisture that
exists across our area (JAN 00z RAOB sampled 1.91 PW, with model
guidance forecasting broad areas of 2"+ PW across parts of north
MS). Marginally strong deep layer shear will support some
potential for a stronger storm or two overnight, but the severe
weather threat will not be widespread. /DL/
&&
.DISCUSSION...
Issued at 248 PM CDT Mon Jul 3 2023
Rest of today through Tuesday...
Increased convective activity is ongoing across the region today.
RAP analysis indicates positively tilted trough over the central
Plains to Texas, helping continued broad ascent persist across the
region. Lowered heights & broad upper level jet combined with deep
moisture of 2+ inch PWs are the impetus for scattered storms
developing across the region. There is some broad westerly bulk
shear but lighter low-level flow. This supports some wet-microbursts
with damaging wind gusts, especially any any storms that can orient
orthogonal to low-level 10-15kt bulk shear & hail up to quarter
size. Microburst composite parameters remain high across north-
northwest MS, southeast AR, & portions of northeast Louisiana.
Will continue to maintain ongoing "Marginal" risk area along & north
of Interstate 20. Some quick, slow moving heavy downpours of +2-3
inches remain possible due to light flow & light backbuilding flow.
However, flash flooding threat will very localized & no mention was
needed earlier in the HWO. With widespread cloudiness, highs will
only peak into the low-mid 90s, with heat indices peaking near 105
degrees, especially for areas along & west of I-55 & southeast along
the Hwy 49 to I-59 corridors. Due to clouds/scattered storm
coverage, no mention of heat headlines are needed.
Showers & isolated storm chances will persist into the evening
hours, with lows falling near or slightly above normal, into the low
to mid 70s. With near tropical deep moisture parked over the region
Tuesday, highs will be limited closer to normals in the low 90s.
With 5-10kt flow in the 0-2km/0-3km layers, some semi-organized
multicell/clusters & wet microbursts are again possible areawide.
SPC made an adjustment to include the entire area in a "Marginal"
risk, which looks good but continued this potential areawide into
Wednesday as mesoscale-driven convection will be difficult to pin
down more localized area for both days. Light flow will favor slow-
moving downpours of +2-3 inches again Tuesday & with high moisture/
light backbuilding flow, low flash flooding threat will again be
mesoscale/localized. One caveat is the SPC HREF indicate some
potential >3 inch prob match mean for heavy totals east of I-55
corridor. Will be something to monitor. Some heat stress could again
peak near 105 degrees in similar areas, so kept the going "Limited"
in the HWO going. /DC/
Tuesday night through Monday...
Scattered showers and storms will be common through mid week as we
continue to deal with routine summer convection. The greatest rain
chances will be mainly in the afternoon during the peak day time
heating hours. Severe potential for these storms will basically be a
coin flip each day. Instability will be rather lackluster as
temperatures continue to cool down, but sufficient lapse rates will
help with some low end microburst potential. The main threats will
be damaging winds and hail up to quarter size. We will continue to
advertise a `Marginal Risk` for severe through Wednesday areawide.
By Thursday, a shortwave will swing across the Upper Midwest/Great
Lakes region, pushing a frontal boundary through the region. This
boundary will stall out just north of our CWA by Friday. Rain
chances will increase this weekend with the greater chances being
mainly in the southern portion of our region. As for the
temperatures, the heat will continue to stick around as highs will
be in the mainly in the low 90s for most of the week with heat
indices around 105. Fortunately, these increased rain chances may
help suppress some of this dangerous heat throughout the day.
Temperatures are expected to rise again by early next week. /LCP/
&&
.AVIATION...
(00Z TAFS)
Issued at 636 PM CDT Mon Jul 3 2023
Scattered to numerous TS, resulting in periodic brief
ceiling/visibility reductions and brief strong wind gusts, are
expected across the area through the TAF period. The greatest
coverage will occur through early this evening, then again on
Tuesday afternoon. Outside of storms, VFR conditions are expected
to prevail. /DL/
&&
.PRELIMINARY POINT TEMPS/POPS...
Jackson 73 91 73 90 / 20 80 40 80
Meridian 73 92 73 90 / 20 80 30 80
Vicksburg 74 91 74 90 / 30 70 40 70
Hattiesburg 74 93 74 93 / 20 70 40 80
Natchez 74 91 74 90 / 30 70 40 70
Greenville 74 90 73 90 / 30 60 20 60
Greenwood 73 92 74 91 / 30 70 20 70
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...None.
LA...None.
AR...None.
&&
$$
DL/DC/LCP
Area Forecast Discussion
National Weather Service North Platte NE
701 PM CDT Mon Jul 3 2023
...00Z AVIATION UPDATE...
.SYNOPSIS...
Issued at 330 PM CDT Mon Jul 3 2023
Key Messages:
- Severe storms are possible across far northern Nebraska late
tonight. The concern is wind damage.
- Additional severe weather is possible Tuesday afternoon, mainly
affecting scntl and swrn Nebraska. The hazards are large hail,
significant wind gusts > 75 mph and locally heavy rainfall which
could cause flooding in some areas.
- Severe weather is possible across wrn Nebraska late Thursday.
The primary concern is large hail.
&&
.SHORT TERM...(This evening through Tuesday night)
Issued at 330 PM CDT Mon Jul 3 2023
An upper level disturbance affecting the Tetons this afternoon
will move east and set off a round of storms off the Big Horns, nrn
Laramie`s and Black Hills. This mostly linear storm complex will move
east overnight, potentially brushing nrn Nebraska before entering
the upper Midwest Tuesday morning. POPs across nrn Nebraska tonight
get a boost to 40 percent using the HRRR and the storms should reach
Sheridan county around midnight.
This disturbance should deposit a residual boundary across ncntl
Nebraska Tuesday morning which will be the focus for storm
development Tuesday afternoon. The POP forecast Tuesday leans on the
short term model blend (STMB) plus CAMs, the NAMnest and HRRR.
Theses models light up the area from Frontier county north to
O`Neill 21z Tuesday afternoon around 21z. It`s important to note
these CAMs can overreact to daytime heating and there is no obvious
upper level support so POPs in that area are limited to 50 percent
Tuesday afternoon. Storm coverage would likely be isolated if no
upper level support is in place. This important detail will become
clear Tuesday.
Winds aloft at h500mb Tuesday will be strong around 30kts and the
MLCAPE near 3000J/KG should support a large hail potential while the
DCAPE near 1500J/KG would suggest a significant wind damage threat
(see SWODY2). PWAT around 1.60 inches supports a locally heavy
rainfall concern. These storms, if they develop, will move southeast
perhaps exiting swrn and ncntl Nebraska by 00z Tuesday evening.
Otherwise, the models are a bit quicker with the cold front Tuesday.
Temperatures could still warm into the 90s south of Interstate 80. A
blend of the STMB and NAMnest was the basis for highs around 70
north to mid 90s far south.
The POP forecast Tuesday night uses the STMB but these showers and
thunderstorms will be post-frontal and the severe weather potential
with this rain is uncertain. Lapse rates in the NAM soundings appear
to become moist adiabatic; the effect of diabatic warming from
earlier rain activity across the cntl high Plains.
.LONG TERM...(Wednesday through Monday)
Issued at 330 PM CDT Mon Jul 3 2023
No change in the forecast philosophy here. A belt of 40-60kt+ winds
will take hold aloft at h500-300mb Wednesday through Monday. The
forecast of interest are Thu, Fri, Sat and Sun. It is during
these days the GFS and ECM are ramping up instability and
generating storm activity, likely severe at times given the very
strong shear predicted in both models. It is worth noting both the
GFS and ECM are on board for storms Thu and Fri but the ECM holds
off on storms Saturday waiting until Sunday. The GFS shows storm
development both Sat and Sun.
The storm mode and evolution are uncertain beyond Thursday. The
situation Thursday looks like it`s off the Laramie Range late
afternoon and then east northeast into wrn Nebraska during the
evening or later.
Beyond Thursday, the shear could be too strong relative to the
instability to support deep convection and there is evidence of a
strong cap in the GFS model soundings at KLBF and KVTN. This could
limit severe storms to just the high Plains and wrn Nebraska. Still,
the NBM has peppered the forecast with POPs daily Thursday through
Sunday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 649 PM CDT Mon Jul 3 2023
VFR conditions are expected through the forecast period outside of
convection.
Initial threat for convection at either terminal will
come late tonight at VTN. Latest trends have been to slow arrival
of strong storms moving out of Wyoming and so have delayed onset
by a few hours from previous forecast but precise timing remains
medium confidence at best. Believe this activity will contain
gusty erratic winds and potential for MVFR ceilings/visibilities.
Will cover with a tempo group for now given brief duration
highlighted by short-term guidance. Expectation is for this
activity to remain north of LBF but will need to monitor.
Round two of convection will occur during the day Tuesday.
Isolated thunderstorms are possible during the early afternoon but
the brunt of any threat will occur late afternoon and evening
along a stalled frontal boundary. Currently anticipating this
boundary to set up near a MCK to ONL line which will keep the
threat south and east of LBF and especially VTN. Trends will need
to be monitored. North of this boundary, however, low stratus is
likely to be prevalent with MVFR CIGs lingering through the bulk
of the period at VTN.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CDC
SHORT TERM...CDC
LONG TERM...CDC
AVIATION...NMJ
Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
1034 PM CDT Mon Jul 3 2023
.SHORT TERM... (Through Late Tuesday Night)
Issued at 237 PM CDT Mon Jul 3 2023
A few showers have developed over the eastern Ozarks and
northeast Missouri into west central Illinois this afternoon. None of
the showers have had updrafts strong enough to produce lightning
yet...but it`s still possible there could be a few rumbles of
thunder. The showers should dissipate by 00Z or shortly thereafter
and the rest of the night looks clear and quiet.
The weak ridge of high pressure which is currently over the Mid
Mississippi Valley will drift east tonight and tomorrow which will
allow the wind to swing around to the south and bring more humid air
back to our forecast area. Meanwhile, the short wave trough
currently over the east central Plains will drift into Missouri
and Illinois tomorrow. Guidance continues to show an area of
convection developing over the eastern Ozarks during the late
morning or early afternoon in the vicinity of the wave as it moves
across the area. This looks reasonable given the convection which
is currently in the vicinity of the wave over Oklahoma. CAMs show
isolated to widely scattered showers and thunderstorms, nothing
as organized as what`s going on in Oklahoma today. All
deterministic guidance only shows 10-15kts of deep-layer shear,
but there`s quite a difference with respect to instability in the
models. On the high end, the RAP shows a broad area of CAPE as
high as 3500-4000 K/Jg, which seems excessive given that most
other guidance shows CAPE more in the 1500-2000 J/Kg range. That
falls more in line with the HREF mean which lends credibility to
the lower values. Regardless, all guidance shows the convection
weakening and dissipating quickly during the early evening.
Carney
.LONG TERM... (Wednesday through Next Monday)
Issued at 237 PM CDT Mon Jul 3 2023
Medium range deterministic GFS and ECMWF are more in sync with
respect to the timing and amplitude of the Wednesday-Thursday short
wave as it moves across the Midwest. This is leading to much more
consistent timing on the FROPA associated with the wave. Current
indications are that the front will be moving slowly into northwest
Missouri Wednesday morning, and convection will blow up ahead of it
Wednesday afternoon. Guidance is showing 1500-2000 J/Kg SB and MU
CAPE with a pretty meager 15-25kts of 0-3km/0-6km shear. If these
numbers hold true, we could see some strong to marginally severe
storms Wednesday afternoon when instability is maximized at peak
heating. Otherwise this doesn`t look like a particularly good setup
for severe storms.
The cold front will continue southeast, pushed as much outflow from
thunderstorms as the synoptic forcing from the short wave. The GFS
is more aggressive with driving drier air southeast into the Mid
Mississippi Valley than the ECMWF is, and is therefore drier on
Thursday. The LREF shows 4 ensemble clusters for the Wednesday-
Thursday time frame indicating uncertainty in the forecast for that
period. The mean QPF in all of the clusters is 0 for most locations
in our area on Thursday, and the majority of the individual members
show little or no precip. The exception is the eastern Ozarks where
all the clusters print out a little mean QPF so limiting the highest
PoPs on Thursday to areas along and south of I-44/I-64 in IL looks
reasonable.
The boundary begins lifting back to the north as a warm front on
Friday as another upper level short wave trough crosses the Rockies
and forces cyclogenesis over the central Plains. The front will be
a focusing mechanism for convection for Friday and Saturday, then
the low level low pressure system will pass across the Midwest into
the Great Lakes Sunday night/Monday dragging another weak cold front
through the Mid Mississippi Valley. LREF continues to show 4
clusters for this period all of which show some degree of troughing
over the central U.S. though the amplitude of the wave and position
of the trough axis are different in each cluster. Regardless, it
does look like a potentially wet/stormy pattern for Sunday/Monday
Carney
&&
.AVIATION... (For the 06z TAFs through 06z Tuesday Night)
Issued at 1032 PM CDT Mon Jul 3 2023
VFR conditions expected overnight with light winds. One exception
could be some localized fog. As of this writing confidence is low
in this happening due to higher level cloud cover preventing
ideal ground level cooling. If it were to occur it is most likely
at SUS and would be gone quickly after sunrise.
Cumulus builds in the late morning and afternoon tomorrow. Showers
and thunderstorms are most likely south of the Missouri River,
with the chances at most terminals remaining too low to mention
in the TAF at this time. These will be diurnally generated and
should die off quickly in the early evening.
Kimble
&&
.PRELIMINARY POINT TEMPS/POPS...
Saint Louis 74 94 75 94 / 5 30 20 50
Quincy 68 92 70 87 / 10 10 10 70
Columbia 69 95 71 89 / 5 10 20 70
Jefferson City 68 96 71 92 / 5 20 20 60
Salem 70 91 70 93 / 20 40 20 30
Farmington 68 93 68 94 / 20 40 20 50
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...None.
IL...None.
&&
$$
WFO LSX
Area Forecast Discussion
National Weather Service Memphis TN
818 PM CDT Mon Jul 3 2023
...New UPDATE...
.UPDATE...
Issued at 807 PM CDT Mon Jul 3 2023
Showers and thunderstorms continue to impact portions of the Mid-
South this evening. A few of these storms are strong with pea
sized hail and 30mph wind gusts possible. As the storms continue
northeast towards the MS/TN border, weakening is expected.
However, a few pop-up storms remain possible over the next few
hours.
Outside of storm development, conditions overnight will be
relatively quiet with lows in the low to mid 70s. Additional
showers and storms are possible Tuesday with damaging winds and
small hail the main threats.
ANS
&&
.SYNOPSIS...
Issued at 221 PM CDT Mon Jul 3 2023
An unsettled weather pattern will continue across the Mid-South
through the work week, providing a chance for showers and
thunderstorms each day. Temperatures will slowly trend down with
highs in the upper 80s to near 90 degrees late week.
&&
.DISCUSSION...
(This evening through next Sunday)
Issued at 221 PM CDT Mon Jul 3 2023
A quasistationary front is laying across the Mid-South this
afternoon, separating a slightly drier continental air mass from
the moist, humid conditions south of the front. A shortwave trough
is moving east across KS/OK at this time and forcing for ascent
is noted downstream of this feature on the water vapor loop.
Convection has developed in two primary areas, one near the MS/TN
border and the other farther south near the Tupelo area.
Mesoanalysis indicates SBCAPE on the order of 4000+ J/kg over
north MS, decreasing poleward, with effective bulk shear around
20-25 kts. Ordinary cells are the primary mode of convection,
though loosely organized multicell clusters are expected as well.
Wind is the primary concern, followed by the potential for locally
heavy rainfall and marginally severe hail. This convection will
begin to push south as it develops a cold pool by late afternoon
and early evening, but additional showers or thunderstorms will be
possible overnight across north MS.
The trough over the Plains will inch toward the Mid-South through
tomorrow, maintaining large scale ascent over the area. Another
round of diurnally driven convection will affect the CWA,
especially in the afternoon. Instability may be a bit weaker than
today, but with shear remaining weak enough to limit storm
organization. Nonetheless, a few pulse storms may be strong to
severe. The trough axis will shift east of the area Wednesday
afternoon, reducing mid-level flow during the afternoon. However,
strong buoyancy will be present area wide during the day,
supportive of disorganized, strong storms. Farther northwest, an
MCS may develop along a cold front and could approach the area
overnight as northwest flow aloft steers it southeast. That said,
the weaker shear may limit the longevity of this system.
There is some uncertainty on the timing of this front. If it
arrives during the day Thursday, convective coverage would be
more widespread, but if it arrives early in the day, it could
shove most of the precipitation south of the area by peak
heating. Will have to keep an eye on this going forward.
Otherwise, the unsettled weather pattern looks to continue into
the weekend. Temperatures during this time will slowly trend to
near or slightly below normal with highs near 90 degrees by the
end of the work week.
MJ
&&
.AVIATION...
(00Z TAFS)
Issued at 621 PM CDT Mon Jul 3 2023
Main track of TSRA will remain across north MS through 03Z, in
and east/west belt of higher CAPE and better position with respect
to the upper jet. Expect loss of daylight and convective outflow
to stabilize the airmass by 03Z or so, with minimal TSRA chances
thereafter.
12Z HRRR and NSSL-WRF CAMs depicted a TSRA cluster around MEM in
the 15Z-18Z time frame. This activity appears to be tied to a an
open upper level trof reflected in the GFS 250mb wind fields and
NAM vertical velocity fields. All that being said, confidence in
TSRA development prior to peak heating (19Z-24Z) is low and the
PROB30 for morning TSRA may be pulled, pending 00Z CAM consensus.
PWB
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...None.
MO...None.
MS...None.
TN...None.
&&
$$
PUBLIC FORECAST...MJ
AVIATION...PWB
Area Forecast Discussion
National Weather Service Morristown TN
753 PM EDT Mon Jul 3 2023
...New UPDATE...
.UPDATE...
Issued at 741 PM EDT Mon Jul 3 2023
Early update this evening due to current convection centered over
Morristown, TN. Cold front is currently oriented across the east
TN valley resulting in an area of convergence. There is a narrow
corridor of showers and storms that have developed within this
area of convergence amidst a moderately unstable air mass. Latest
HRRR suggests isolated showers and storms will continue to
develop within this area of convergence through midnight. Bumped
up POPs from Knoxville and points eastward toward the east TN
mountains.
&&
.SHORT TERM...
(This evening through Tuesday)
Issued at 241 PM EDT Mon Jul 3 2023
Key Messages:
1. Scattered showers and storms through early evening. Some strong
storms are possible producing strong gusty winds, brief heavy
rain, and lightning.
2. Areas of fog will develop overnight through early Fourth of
July. Some of the fog may become locally dense.
3. A chance of mainly afternoon storms return Fourth of July
across the higher terrain and southeast Tennessee/southwest North
Carolina. Elsewhere, mostly dry.
Discussion:
Currently a boundary is drifting southeast across the region and
located roughly from far southeast Kentucky, northern Plateau to
southern middle Tennessee. This boundary will continue to drift
slowly south overnight.
Through this Evening, water vapor shows the upper trough across
the Ohio valley with a short-wave over southern IN. Jet streaks
are moving across Kentucky and northern Tennessee enhancing
convection across northern Alabama and parts of east Tennessee.
Latest mesoanalysis MLCAPES of 1500-2000. DCAPE are less today
with values of 500-800. However, drier mid-level air will move
into the region this evening.
Effective shear is 20-25kts so some organization to the multi-
cell clusters are possible. PWs are slow decreasing with the
incoming mid-level dry air but still enough moisture to produce
brief heavy rains.
Overall, as the boundary across moves environment able to produce
strong/gusty winds, brief heavy rain, and lightning with the
events through early evening.
For Tonight, convection dissipates with the drier air aloft
allowing for better radiational cooling. Due to the recent rains,
plenty of boundary layer moisture, plenty of breaks in the clouds,
and calm winds, areas of fog will likely develop. Some of the fog
will likely be dense.
For the Fourth of July, fog dissipate by mid-morning giving way to
partly cloudy/mostly sunny sky. The weakening boundary will be
near the Tennessee/Alabama-Georgia state line. The boundary along
with the terrain features will produce mainly scattered diurnal
convection there in the afternoon. HREF depicts these areas as
well. Elsewhere, mainly dry with seasonal warm and muggy
conditions.
&&
.LONG TERM...
(Tuesday night through next Monday)
Issued at 241 PM EDT Mon Jul 3 2023
Key Messages:
1. Shower and thunderstorm chances continue through long term
forecast.
2. Temperatures will be near normal this week and weekend.
Discussion:
Old frontal boundary, the front that is moving through the forecast
area this afternoon and evening is expected to be just south of the
region Tuesday night. Expecting a few showers and storms during the
evening Cumberland Plateau and southern Valley southwest North
Carolina through the Smokies. Then skies will be clearing overnight
with some fog possible especially where rainfall occurred.
Then Wednesday the frontal boundary will likely break up with weak
high pressure over the region. Increasing moisture to the west and
south will surge back north and enhance rain chances Wednesday
afternoon and evening but should decrease quickly by sunset
Wednesday night. A few storms along the plateau could be strong with
SPC showing the chance of marginally strong storms mainly west of
the plateau Wednesday. Coverage of showers and storms is somewhat
uncertain with the NAM and ECMWF models wetter, more coverage and
the GFS model drier Wednesday.
Thursday the pattern is about the same. GFS may be showing slightly
more convection than other models as a weak front will be moving
into middle Tennessee and Ohio Valley as new upper trough moves
south out of Quebec into the Great Lakes late Thursday and Friday.
The frontal system slowly moves across Tennessee later Thursday and
Friday. There will be increased showers and storms again Friday and
lower Saturday as the front makes it just south and southeast of
Tennessee. Sunday and Monday rain chances increase once again as the
boundary moves back north and stalls right over the region Monday.
Another significant shortwave moving southeast through the trough
may enhance showers and storms Sunday night in Monday as well.
Temperatures each day will be near average in the mid to upper 80s
northeast and central valley lower elevations and near 90 to lower
90s in the southern appalchians. Average rainfall amounts for the
five day period ending Saturday morning will be mostly around 0.50
inches except around an inch in the higher eastern mountains of
Tennessee and also across southwest North Carolina.
&&
.AVIATION...
(00Z TAFS)
Issued at 727 PM EDT Mon Jul 3 2023
Mostly VFR through the period, but somewhat of a tough aviation
forecast. 1) hard to say how widespread and dense fog may be
overnight. Cirrus blowoff currently moving in from southwest
doesn`t favor fog, but if we clear out later tonight some fog is
possible. Will go MVFR at CHA and TYS, and down to IFR at TRI. 2).
Thunderstorms are just southwest of TRI at the current hour.
Believe they should stay just south of the terminal so no mention
in TAF, will amend if needed.
&&
.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN 71 89 71 89 / 30 30 20 60
Knoxville McGhee Tyson Airport, TN 70 88 71 88 / 30 20 10 40
Oak Ridge, TN 69 88 69 87 / 20 20 10 40
Tri Cities Airport, TN 66 86 66 87 / 30 10 10 40
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
SHORT TERM...
LONG TERM....TD
AVIATION...
Area Forecast Discussion
National Weather Service Spokane WA
355 PM PDT Mon Jul 3 2023
.SYNOPSIS...
Warm and dry weather conditions will continue this week across the
region. Isolated mountain showers and thunderstorms are possible
for the Fourth of July Holiday and again for the weekend.
&&
.DISCUSSION...
This afternoon there are Red Flag warnings active for North-
Central Washington from Omak through Moses Lake. The fuels in
central Washington have been able to dry out region-wide the past
few days; PWATs are near 40% of normal, RH values are between
10-15, high above 80 degrees Fahrenheit, and winds of 10-15 mph,
so fires could spread rapidly. Winds should be below red flag
criteria elsewhere, so the red flag warning has been confined to
the Okanogan valley and Moses Lake vicinities. Tomorrow, RH values
begin to rebound with weaker winds, pushing the area below
critical fire weather thresholds. We are currently under a weak
trough which will bring some northerly flow and with it, smoke
from Canada. This afternoon there is some light smoke aloft,
giving the CWA a little haze, though air quality is unaffected.
Overnight there will be a denser band of smoke pushing through the
area which may mix down to the surface tomorrow afternoon. This
could impact air quality, though it will make firework shows
spectacular.
Tomorrow afternoon into early evening, there will be enough
moisture in Northern Washington and the ID Panhandle that the
northerly flow will be able to form some weak thunderstorms with
the help of orographic lifting. The HRRR and HRW-NSSL have more
widespread precipitation in the same areas, but the NAM has
confined any precipitation to the NE ID Panhandle. The trough will
provide some upper-level divergence which should assist storm
formation, though shear and CAPE are extremely limited so strong
storms are unlikely. The storms that do form will begin to
strengthen after 2:00 PM and wane by 6:00 PM, and could bring
brief gusty outflow winds to the rest of the region in the evening
which could impact some holiday activities. Winds begin to weaken
and RH will begin to rise overnight Tuesday so fire concerns will
be lessened.
On this Fourth of July, beneath the beautiful sky,
Strong winds are set to come, as the flags wave high.
From Canada they`ll blow, in a northerly flow,
Mixing smoke down, making for a spectacular show.
Humidity lays low, especially in the Waterville Plateau,
Leaving the air dry, under the star spangled night.
For each sparkler`s dance, and every firework`s burst,
A reminder to use water and shade, keeping the summer heat dispersed.
Beware, dear friends, of fire`s unforgiving risk,
In these perfect conditions, it could burn without assist.
Keep celebrations safe, while the rockets glare,
In our land of the free, of local burn bans beware.
On this Fourth of July, let freedom ring loud,
But heed Mother Nature, and be safe in your crowd.
Be mindful, be safe, let your joy be free,
Happy Independence Day, to our beautiful country.
/Sinowitz
Wednesday through Sunday: The Pacific Northwest will remain on the
eastern edge of broad ridging located over the northeast Pacific
through the end of the work week. Initially, this will allow haze
from Canadian wildfires to slide into the region Wednesday and
Thursday. Temperatures will be the warmest on Thursday and Friday
under influence of the ridging to our west, although the degree of
smoke or haze may slightly influence the afternoon heating. Our heat
risk tool indicates widespread moderate risk for heat related
illnesses through Friday. This level of heat mainly affects
individuals who are sensitive to heat, especially those without
effective cooling or adequate hydration. The Wenatchee River valley
sticks out for Thursday, where the heat risk tool indicates a major
risk for heat related illnesses, which will affect anyone without
effective cooling.
Late Friday into Saturday, models are in general agreement on an
upper level trough to slide into the region from the northwest. The
overall influence this trough will have on the weather across the
Inland Northwest remains a bit unclear, as a subset of ensembles
suggest it wont even put a dent in the high temperatures for
Saturday and Sunday, and another subset has the temperatures
dropping back to near normal values. There is agreement that this
feature will bring an increase in moisture, supporting afternoon
showers and thunderstorms this weekend. /vmt
&&
.AVIATION...
00Z TAFs: Breezy north winds are continuing to gust down the
Okanogan Valley into the Waterville Plateau through the early
evening. Elsewhere, northerly breezy winds will persist through
the overnight hours before shifting northeast or east (DEW, COE,
SFF, GEG) early Tuesday morning. High level smoke from wildfires
in Canada is drifting south into the area. High resolution models
suggest haze to mix down to the surface around Omak and the
Methow Valley into Wenatchee, Ephrata, and Moses Lake by Tuesday
morning, although significant visibility reductions are not
expected at this time. VFR aviation conditions expected the next
24 hours.
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 53 85 56 89 58 93 / 0 0 0 0 0 0
Coeur d`Alene 50 83 53 87 58 92 / 0 0 0 0 0 0
Pullman 45 83 48 87 55 91 / 0 0 0 0 0 0
Lewiston 58 91 60 95 64 98 / 0 0 0 0 0 0
Colville 43 85 48 88 53 93 / 0 10 10 0 0 0
Sandpoint 47 80 49 84 54 90 / 0 10 20 0 0 0
Kellogg 51 80 54 83 60 88 / 0 0 0 0 0 0
Moses Lake 56 91 56 96 60 98 / 0 0 0 0 0 0
Wenatchee 63 91 65 93 68 96 / 0 0 0 0 0 0
Omak 58 91 60 94 63 97 / 0 0 0 0 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...Red Flag Warning until 11 PM PDT this evening for Western
Columbia Basin (Zone 707).
Red Flag Warning until 11 PM PDT this evening for Okanogan
Valley (Zone 703)-Waterville Plateau (Zone 706).
&&
$$
Area Forecast Discussion
National Weather Service Pittsburgh PA
942 PM EDT Mon Jul 3 2023
.SYNOPSIS...
Isolated precipitation chances are expected for the 4th of July
as ridge builds to our west. Temperatures will climb 5 degrees
above the climatological average Wednesday and Thursday.
&&
.NEAR TERM /THROUGH TUESDAY/...
9pm Update: A narrow line of convection is currently moving
through the region along a sfc trough north of Pittsburgh.
Elsewhere, convection has mostly wrapped up with the loss of
diurnal heating. With this latest forecast update, thunder
chances have been removed during the overnight period.
Noted clearing to the north, sufficient sfc moisture, and light
winds may enhance the formation of fog after 2am. The last few
runs of the HRRR suggest a decrease in visibility starting near
Lake Erie and expanding south. If dense fog does develop it will
likely be situated near I-80. Diurnal heating after dawn will
likely dissolve any fog between 6am and 8am.
Despite an upper-lvl trough advancing east on Tuesday, guidance
does show a chance of showers, mainly due to upsloping under
northwest flow. Therefore, the highest probabilities for
precipitation will be focused along the higher terrain. With
more sunshine and rising heights expect readings a bit higher
and into the lower 80s most locations.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
An upper ridge builds over the eastern Great Lakes and
Northeast on Wednesday. A weak disturbance sneaks to its south
over the local area and could help excite some weak shower and
thunderstorm activity primarily over higher terrain given
assistance from the upslope flow. However, coverage would be
isolated at best with updrafts battling larger-scale subsidence
and entrainment from a drying deep- layer moisture profile.
Better rain chances return from west to east on Thursday as the
upper ridge shifts east and mid/upper flow transitions to
southwesterly ahead of the next approaching trough. Thursday is
also looking like the warmest day this week, with guidance
trending towards high temps in the upper 80s and even perhaps
reaching 90 in some places (NBM 90F probabilities have
increased from teens across our area to 30-50 percent range).
The amount of heating will partially depend on how quickly
cloud cover associated with the aforementioned upper trough
overspreads the area. A faster progression and earlier arrival
time for the clouds could mitigate the 90-degree potential being
hinted at in current probabilistic guidance. Will continue to
monitor, but for now opted to maintain upper 80s and kept
mention of 90F out of the forecast.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
Mostly zonal mid- and upper-level flow sets up across the
Northern Plains and Great Lakes to begin the extended term. A
series of weak disturbances embedded within this flow pass over
the local area Friday and Saturday, supporting chances for
showers and storms each day. Kept the forecast relatively
simple and maintained highest precip chances over the higher
terrain since this is still a ways out and we`re talking about
small/subtle features that will be driving convective potential.
Guidance currently favors a more established upper trough
disrupting the zonal flow and pushing across the eastern Great
Lakes Sunday into Monday, which would bring a greater coverage
of showers and storms to the area on those days. Made sure PoPs
reflect this potential as well.
Nothing notable in the extended term with respect to temps.
Expect highs in the low 80s for much of the area throughout the
extended term, right around or perhaps a hair below normal for
this time of year.
&&
.AVIATION /01Z TUESDAY THROUGH SATURDAY/...
The atmosphere remains nearly saturated through the entire
column in remnant tropical moisture. Into tonight, diurnal
cooling will reinforce surface and low- level saturation. This
will result in falling cigs, with most ports dropping to LIFR by
daybreak except ZZV with drier air aloft. Rain from the last 24
hours may also reinforce vis restrictions at the surface, most
likely for DUJ and FKL with the most cooling forecast.
Cigs will improve rapidly into the day with scattering likely in
mixing. VFR will return by the afternoon. Morning showers are
possible in MGW with a trough passage, but generally unlikely.
.OUTLOOK...
Restrictions may briefly return Tuesday night, but otherwise,
VFR is expected through the rest of the week.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
PA...None.
OH...None.
WV...None.
&&
$$
SYNOPSIS...Hefferan
NEAR TERM...Craven/Hefferan
SHORT TERM...Cermak/Shallenberger
LONG TERM...Cermak
AVIATION...Milcarek
Area Forecast Discussion
National Weather Service Pendleton OR
809 PM PDT Mon Jul 3 2023
.EVENING UPDATE...No changes from the previous forecast. Current
satellite shows no clouds over the region except for a few
scattered cumulus over the Wallowa Mountains. There is however,
haze lingering in the air as the smoke from Canada is creeping
back in over the region as well as local wildfires. HRRR smoke is
showing some smoke reaching the surface so, please pay attention
to the air quality in your area. Also, the Tunnel 5 fire in the
Gorge will affect the air quality as well as visibility. Wind this
evening will be mostly terrain driven with speeds of 5-11 mph.
Temperatures tonight will be in the low to mid 50s across much of
the CWA with a few local areas seeing the 60s such as in the Basin
and through the Gorge. 90
&&
.PREV DISCUSSION... /issued 414 PM PDT Mon Jul 3 2023/
Updated aviation discussion
SHORT TERM...Today through Wednesday night...Sensible weather
concerns revolve around the warm-hot temperatures, otherwise scant
wind or precipitation concerns. The main highlights include:
- above normal highs around 5 degrees today peaking Wednesday
around 10 degrees above normal,
- moderate heat risk across north central OR north and northeast
into the Kittitas Valley and Basin to foothills of the Blues
Wednesday, and
- haze from fires.
Latest water vapor imagery shows a shortwave trough crossing into
eastern OR with cyclonic flow dominating the PacNW. Latest day
cloud phase RGB imagery shows some mountain and diurnal cu across
parts of the WA Lower Basin, northern Blues, and Wallowas. Some
smoke apparent with the Tunnel 5 five near Hood River. The base of
this shortwave trough will move into south central MT as another
embedded disturbance/weak vort max behind it moves into southern
WA by tomorrow morning. A thermal introduced trough is anticipated
to evolve and be along the western slopes of the Cascades
tomorrow. Meantime, east of the Cascades, only light breezes are
expected with latest probs for max sustained winds greater than 20
mph at 10 percent or less area-wide. Modest chances for 13 mph or
higher sustained winds with best signal for these winds limited to
exposed ridges, except for parts of central OR. Otherwise, modest
500 mb height rises will be seen upstream in the eastern North
Pacific through the short-term period with the aforementioned weak
cyclonic flow at the mid-levels continuing on Wednesday. Later on,
continued dry conditions with dry profile Wednesday with the low-
level thermal ridge extending north across eastern OR. Highs will
read a little higher and approach 100 degrees across parts of the
eastern Gorge and lower Basin Wednesday. Of note, NBM chance of
exceedance for 100 or more Wednesday is low (less than 40%)
implying low confidence, which is reasonable given current
forecast and guidance with highs just below the 100 F threshold.
Overall, high confidence in the forecast owing to good agreement
between the main ensemble systems and HREF.
LONG TERM...Thursday through Monday...The long term sees us break
away from the extended heat spell into a more manageable and
seasonable heat over the weekend, but by early next week it`s
likely we`ll be shifting back into increased heat once again.
Guidance indicates the long term begins under westerly flow that
will shift to a more southwesterly pattern due to troughing/low
pressure moving into Vancouver Island. Guidance expects this to be
a noteworthy feature for the region through the weekend, with
Monday ending under a weak westerly/southwesterly flow between
high pressure across the desert southwest and troughing offshore
to the northwest. Deterministic guidance continues to struggle on
how the low/trough evolve, with the ECMWF expecting more energy/a
deeper low offshore that will then swing towards the region and
weaken, whereas the GFS expects a stronger low across Vancouver
Island that will then dip down into Washington. Looking into
ensembles, agreement on some form of troughing with the clusters
showing the differences indicated by the deterministic models.
In any case, looking likely for a slight cool down thanks to the
cooler air associated with the trough, with a greater cooldown
possible if the GFS is accurate. The NBM lines up between the two
for the forecast period, giving us unseasonable warmth to begin
the long term with temperatures in the 90`s to low 100`s in the
Columbia Basin, dropping by Saturday to 80`s to 90`s with a slow
warming trend thereafter. On the note of the warmth, heatrisk
indicating consideration for some advisories or warnings, once
again primarily across the aforementioned Columbia Basin, but also
including portions of Yakima and Kittitas Valley. As it`s still a
bit early, we will not be adding any headlines in, but continue
to monitor moving into the holiday tomorrow to see if these are
warranted. The NBM indicates nearly widespread agreement on
greater than 90 degree warmth, around 80-100% probability. But
moving into greater than 100 degrees, the NBM probabilities still
don`t want to fully commit to the Columbia Basin`s potential heat,
only ranging between 30-50%, but these are an improvement from a
few days ago, and should continue to rise int he coming days.
Finally as the trough descends and we see a bit more
southwesterly flow, models have begin to indicate the possibility
of a few thunderstorms for the high terrain from Central OR up
through Northeast OR. The NBM hasn`t quite caught up to this, so
following our neighbors have added in slight chance of
thunderstorms with low confidence (10-20%). Goatley/87
AVIATION...00Z TAFs...VFR conditions will prevail during the next
24 hours at all terminals. However, there may be some smoke at KDLS
from the Tunnel 5 wildfire near Hood River, causing MVFR conditions.
There may be smoke also at KYKM due to wildfires in Canada, causing
haze. However, most of the smoke from the Canadian wildfires will be
aloft, which may reduce visibility at times to MVFR. There may be
MVFR conditions due to smoke also at the surface at KYKM at times.
There will be locally breezy winds this evening at KPDT, KRDM, KBDN,
and KPSC this evening until 06Z-09Z, and then winds will become
light and under 10 Kts at all terminals by late this evening. 88
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 54 89 56 94 / 0 0 0 0
ALW 57 93 60 98 / 0 0 0 0
PSC 60 94 61 98 / 0 0 0 0
YKM 58 93 59 95 / 0 0 0 0
HRI 57 95 57 100 / 0 0 0 0
ELN 55 93 57 93 / 0 0 0 0
RDM 48 88 50 93 / 0 0 0 0
LGD 49 85 50 89 / 0 0 0 0
GCD 49 86 51 91 / 0 0 0 0
DLS 59 96 61 99 / 0 0 0 0
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...None.
WA...None.
&&
$$
SHORT TERM...80
LONG TERM....87
AVIATION...88
Area Forecast Discussion
National Weather Service Pocatello ID
110 PM MDT Mon Jul 3 2023
.SHORT TERM...Tonight through Tuesday night. A low pressure system
remained positioned over CNTRL Canada early this afternoon while a
well defined disturbance was noted rotating through the WRN
periphery of the low into the NW states. This disturbance is
expected to rotate into the Idaho Panhandle this afternoon and
evening adding dynamical forcing to an already unstable atmosphere
across SE Idaho. As a result, the Storm Prediction Center has placed
a portion of SE Idaho along and SE of I-15 and I-86 in a Marginal
Risk of Severe Thunderstorms. The strongest thunderstorms will
likely continue until around 9 PM before things begin to quiet down
across the region. Breezy winds are also anticipated across the
CNTRL mountains and Snake River Plain this evening. Wind speeds will
likely remain below Lake Wind conditions across American Falls
Reservoir but choppy. The SW extent of the Canadian low lingers over
SE Idaho Tuesday with a chance of showers and thunderstorms expected
up along the Montana and Wyoming divide during the afternoon. Once
again, locally breezy conditions are anticipated but remaining below
Advisory levels. We may see a north wind trying to work down the
Snake River Plain late Tuesday afternoon which may impact American
Falls Reservoir during the evening hours. Daytime highs begin to
cool Tuesday following the passage of this evenings disturbance on
the gradual onset of northerly surface flow late in the day. Huston
.LONG TERM...Wednesday through next Monday.
Zonal flow will prevail for Wednesday as SE Idaho remains in between
building high pressure to the south and broad troughing to the north
keeping unsettled weather chances continuing albeit mostly confined
to the mountains starting Thursday. Dry conditions are expected for
Wednesday with isolated chances for showers and thunderstorms
Thursday, increasing in coverage for Friday through the weekend. A
series of shortwave troughs working through the NRN Rocky Mountains
will help to drive moisture into our area as upper level flow
transitions to being more out of the SW helping to bring afternoon
highs back into the upper 70s to low 90s. ENS GFS and ECMWF
solutions remain in good agreement with the NBM through the extended
period with best chances for storms each day further north and east
in the Central Mountains and ERN Highlands as mostly dry conditions
prevail across the Snake Plain. Looking ahead towards next week,
that very persistent broad troughing that was in place for much of
this week will shift east onto the Great Plains allowing for warmer
temperatures to advect north as dry conditions return for for the
start of mid-July. MacKay
&&
.AVIATION...For the 18Z TAFS through 18Z Independence Day.
Predominant VFR conditions continue as a cold front passing through
SE Idaho today. This front will bring isolated to scattered showers
and thunderstorms predominantly starting off as virga transitioning
to thunderstorms in the afternoon. Best chances for lightning will
remain confined south and east of the Snake Plain with HREF
lightning probabilities showing less than a 30 percent chance at
KPIH, KIDA and KBYI, a less than 10 percent chance at KSUN, and a 40
to 60 percent chance at KDIJ. Winds synoptically will increase with
gusts out of the W/SW between 20 to 30 kts at all terminals. Post-
cold frontal passage, clear skies return and winds subside as broad
northerly flow descends over the region. HRRR and RAP Smoke models
show increased haze and smoke descending out of the north associated
with Canadian Wildfires however impacts aloft and at the surface
will be very limited. Mostly dry conditions prevail for Independence
Day with only slight chances for afternoon showers and thunderstorms
across the Upper Snake Plain at KIDA and KDIJ. MacKay
&&
.FIRE WEATHER...A quick moving cold front today will spur isolated
to scattered showers and thunderstorms starting off predominantly as
virga transitioning to thunderstorms in the afternoon. Best chances
for lightning will be further south and east particularly in the
mountains with winds increasing regionwide with gusts to around 30
to 40 mph, locally higher across the Arco/Mud Lake Desert. Stronger
thunderstorms will be capable of producing wind gusts in excess of
50 mph, small hail, and brief moderate to heavy rain. As showers and
storms shift east for Independence Day, clear skies will prevail
with afternoon highs in the upper 60s to mid 80s as slight chances
for afternoon showers and thunderstorms continue across the Upper
Snake Plain.
Zonal and southwesterly flow returns for Wednesday bringing dry and
warmer conditions midweek with near critical to critical afternoon
humidities particularly across the Magic Valley and Great Basin
Wednesday and Thursday. Isolated afternoon showers and thunderstorms
return for Thursday in along the Continental Divide region
increasing in coverage for Friday through the weekend in the Central
Mountains and Eastern Highlands as afternoon humidities see some
minor improvement. Following slightly cooler conditions Tuesday and
Wednesday, afternoon highs will remain consistent in the 70s to low
90s each day ahead of a more pronounced ridge of high pressure
favored to develop early next week bringing a return to warmer and
drier conditions starting next Monday. MacKay
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Area Forecast Discussion
National Weather Service Blacksburg VA
1006 PM EDT Mon Jul 3 2023
.SYNOPSIS...
The Mid Atlantic states and Carolinas will stay in a persistent
summer pattern of humid weather and near normal temperatures
this week. After a weak front goes through tonight, Tuesday
will have a lower chance of storms. The chance of showers and
thunderstorms then increases each day, peaking at the end of the
week with the passage of another front.
&&
.NEAR TERM /THROUGH TUESDAY NIGHT/...
As of 745 PM EDT Monday...
Widespread severe threat is diminishing this evening, but a few
strong/isolated severe storms could continue for a few more
hours.
Current RAP analysis has the highest zone of instability east of
the Blue Ridge Mountains and best convergence is along the
lee of the Blue Ridge. Here along this convergence zone, a few
storms have developed within the last hour or so. These storms
have shown signs of strengthening as they move east into a more
favorable atmospheric corridor. Very heavy rain, frequent
lightning, and strong wind gusts will be the main threat with
any of these storms this evening.
To account for this Severe Thunderstorm Watch #439 remains in
effect until 10 PM EDT tonight for areas east of the Blue Ridge.
As of 240 PM EDT Monday...
Scattered storms, some severe through this evening, then warm
and dry for most of the forecast area for July 4th...
Showers and thunderstorms are developing across the area, as our
little cap has eroded and more forcing is arriving in the form
of a summer cold front. While we currently have a few widely
scattered storms across VA and northern NC, there is a more
organized line of storms moving through SE WV. Apart from these,
a remnant MCV over central NC was helping to fuel stronger
storms to our east and southeast. A Severe Thunderstorms Watch
has now been issued for areas along and east of the Blue Ridge.
The best theta-e values were pooling over eastern VA and NC, and
expect the more damaging downburst winds to occur closer to the
coast. However, we have temperatures in the 70s and 80s, with
dew points in the 70s. The resultant CAPE along with the
moisture convergence along the higher terrain and the front will
trigger a few strong to severe storms in our area. Most of this
activity will diminish after 8 PM. Damaging winds will be the
main concern. In addition, PWATs of 1.4" and higher will support
heavy rain and the evaporative cooling should increase downdraft
winds.
Tonight, skies will clear out partly, but expect stratus and
fog to develop over the mountains. Lows will range from the low
60s to the low 70s. July 4th looks like we will see a fair
amount of cirrus with low rain chances. If anything we could see
a few showers across parts of WV and also NC. For most it
should be a good night for fireworks. Daytime highs will be in
the upper 70s to mid 80s for the mountains, and in the upper
80s/low 90s for the Piedmont.
Confidence is high in the near term forecast.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
As of 250 PM EDT Monday...
Above normal temperatures and humid conditions with limited
chances of showers and storms until Thursday night...
As of 100 PM EDT Monday...
A shortwave ridge is expected to build over the region during
most of this portion of the forecast. This feature will help
limit the extent of showers and storms to primarily those formed
by daytime heating and/or differential heating. Any that do
form will likely dissipate quickly after sunset.
This pattern will start to change Thursday night with the
approach of a cold front, and an increased likelihood of more
organized convection continue into, or forming, during the
overnight hours. The farther west in the forecast area one is,
the greater this potential will be.
Temperatures during this portion of the forecast will average
around five degrees above normal.
Confidence in this portion of the forecast is moderate to high.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
As of 250 PM EDT Monday...
Shower and thunderstorm activity increase again Friday into
Monday...
While during mid-week we are expecting a bit of a slow down on
precipitation chances across the area. The numbers look to ramp
up on average across the region Friday through Monday. About the
only confident feature during this time period is the arrival
of a cold front on Friday across the region.
For the weekend through Monday, model guidance is highly
variable on first the speed with which the cold front exits
the region. Secondly, timing, track, and impacts of additional
upstream shortwave troughs and their association showers and
storms into Monday is highly variable.
However, with this said, for different reasons, the various
guidance does keep the area on the wet side for most of this
four day period. Perhaps Saturday will be our slow day among the
four.
Temperatures during this portion of the forecast are still
expected to average around five degrees above normal.
Confidence in this portion of the forecast moderate for the
increases precipitation chances, but on the low side regarding
the timing and placement of the showers and storms each day.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
As of 800 PM EDT Monday...
ROA, LYH, and DAN should scatter out tonight behind the summer
cold front. LWB, BLF, and BCB will have a chance for
LIFR/IFR/MVFR fog and stratus (more likely) overnight into
Tuesday morning. Tuesday looks VFR once the stratus and fog
improve by 15Z. Expect west winds of 6-12 kts tomorrow with a
few gusts to 20 kts.
EXTENDED AVIATION OUTLOOK...
Scattered MVFR thunderstorms are possible each afternoon and
evening from Wednesday through Saturday.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...None.
NC...None.
WV...None.
&&
$$
SYNOPSIS...AMS/SH
NEAR TERM...SH
SHORT TERM...BMG/DS
LONG TERM...DS
AVIATION...BMG/SH