Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 08/05/23
Area Forecast Discussion
National Weather Service La Crosse WI
1040 PM CDT Fri Aug 4 2023
.DISCUSSION...(This evening through Friday)
Issued at 239 PM CDT Fri Aug 4 2023
Key Messages:
- Widespread rainfall likely overnight Saturday through late
Sunday, timing and amounts are uncertain.
- Temperatures below normal next week with rain chances returning
later in the week.
For This Afternoon and Evening...
A weak boundary is located across southeast Minnesota, northeast
Iowa, and southwest Wisconsin. Some low moisture (dew points mainly
around 70F) have pooled along and west of this boundary. With
temperatures ranging from the mid-80s to near 90, surface-based
CAPES have climbed into the 2000 to 2500 J/kg range. This has
resulted in the development of scattered showers and storms. With
soundings showing steep lapse rates and a dry sub-cloud boundary,
any storms will be capable of producing wind gusts of 40 to 50 mph.
In addition with precipitable water values between 1 and 1.3 inches
and warm cloud layer depths of 3500 meter, these storms will be
capable of producing heavy rain. These storms will gradually
dissipate this evening with the loss of diurnal heating.
Saturday...
With surface-based CAPES ranging from 1500 to 2000 J/kg and a weak
boundary just to our west and south, there may be some isolated to
scattered showers and storms (20-30%) in parts of southeast
Minnesota, northeast Iowa, and southwest Wisconsin on Saturday
afternoon and evening. This is in good agreement with the CAMs. High
temperatures will be mainly in the lower and mid-80s.
Showers and Storms late Saturday into Sunday:
The synoptic setup for this weekend continues to feature a 500mb
trough advecting through our region developing a surface low over
the Central Plains on Saturday with an associated warm front. As the
low progresses eastward and deepens, 850mb WAA and moisture
advection will increase, particularly over northeastern Iowa and
southwestern Wisconsin with a trailing cold front to the south
developing as the day progresses, a setup that might be more common
to see in the winter or spring months. Uncertainty still remains
between guidance in the exact track and intensity of the surface low
for the weekend which could have a significant impacts on
precipitation amounts and severe weather potential.
A couple of different scenarios are in play this weekend, the 04.15
RAP favors a more northerly solution for the development of the
surface low which would allow the warm sector to extend further
north increasing our instability as shown in the RAP with 1000-1500
J/kg of MUCAPE in northeastern Iowa and southeastern Minnesota
Sunday morning. The other trend shown more in the 04.06 GFS, 04.12
NAM and 04.12 EC has been to keep instability minimal with only a
couple of hundred J/kg of MUCAPE in the warm sector. When
considering these solutions with regards to severe potential, this
is looking more like a tornado or nothing type of environment when
considering respectable 0-1km shear of 20-30 knots and low LCLS with
the passage of the surface low, could result in an isolated tornado
Sunday if storm updrafts are strong enough to support it.
The main significance of this event is the possibility for heavy
rainfall going into Sunday. PWATs of around 1.5" to 1.75" in the
04.12 NAM and 04.12 GFS are displayed Sunday afternoon with warm
cloud depths around 3.5kft to 4kft, especially in southwest
Wisconsin. One picture that is pointed out by the 04.12 NAM is
that the better warm cloud depths are displaced from the higher
PWATs which may limit the ability for our region to realize the
moisture that is present. As a result, generally not expecting
widespread flash flooding to be a concern, especially with the
6-hr RFC flash flood guidance suggesting most of northeast Iowa,
southeast Minnesota and west- central Wisconsin needing over 3
inches of rain in a 6-hr period to materialize a flash flood
threat. However, cant completely rule out isolated flooding if
storms train over the same locations.
Rainfall amounts with the event look to be around an inch but
variance between guidance on amounts and the placement of the
surface low decreases confidence in forecast amounts. The GEFS and
EC both display a high degree of confidence (80-90%) of seeing 0.5"
or more of precip. Some disagreement begins at the 1" mark with the
EC probabilistic ensembles showing higher confidence for amounts of
an inch (40-50%) than the GEFS with lower confidence (20-30%). An
interesting note with the 04.12 NAM has been to trend the surface
low further south into southern Iowa, this solution would suggest
minimal rain amounts for north-central Wisconsin and would overall
limit the timing on precip to mostly Sunday. Additionally, This
would keep precip totals on the lower end north of the MN/IA border.
The 04.12 HREF ensembles have picked up on this drier trend as well
which suggest hardly any precip through Sunday morning east of the
Mississippi River with a similar track for the surface low as the
NAM solution. Furthermore, the 04.12 CAMs generally do not want
precipitation moving into our region at all Saturday night into the
early morning Sunday which lowers confidence in higher rainfall
amounts.
In short, generally not expecting a widespread severe weather event,
with only a few stronger storms possible in northeastern Iowa and
southwestern Wisconsin depending on what guidance verifies for the
position of the surface low on Sunday. Some rotation within storms
is possible near the surface low as well which could produce an
isolated tornado. Otherwise, mostly looking for the possibility of
heavier rain, particularly during morning and afternoon on Sunday,
with amounts over an inch possible depending on what guidance
verifies. However, confidence is decreasing when considering the
most recent deterministic runs of the EC and NAM.
Next Week:
After the passage of the trough for this weekend, northwesterly to
westerly flow will return keeping us dry and below normal
temperature wise for the first half of the week with highs in the
70s and lower 80s. There is good agreement amongst the Canadian and
EC to keep us below average through next week with the GEFS still
exhibiting a warm bias as has been seen in previous weeks. Early
indications in the long range guidance suggests a possible trough
that could bring shower and storm chances back for the region late
week, with the 04.06 GFS being the most enthusiastic with this
possibility at the moment.
&&
.AVIATION...(For the 06Z TAFS through 06Z Saturday night)
Issued at 1040 PM CDT Fri Aug 4 2023
VFR conditions expected through this TAF period with SCT/BKN
mid/high clouds and persistent E/SE winds up to around 10 kts.
Shower/storm potential looks very limited through Saturday evening
(less than 15% chance).
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
DISCUSSION...Boyne/Naylor
AVIATION...JM
Area Forecast Discussion
National Weather Service Cleveland OH
920 PM EDT Fri Aug 4 2023
.SYNOPSIS...
High pressure will build across the Great Lakes tonight and
Saturday, before drifting east of the region Saturday night.
This will allow low pressure to slowly approach from the Midwest
Saturday night and Sunday, crossing the region late Sunday or
Monday.
&&
.NEAR TERM /THROUGH SATURDAY NIGHT/...
920 PM Update...
Increased the fog coverage in NW PA overnight, but should not be
an issue near the lakeshore areas. Minor temperature edits.
Otherwise dry.
Previous Discussion...
The cold front now appears to be south of US 30 as of 1930Z as
surface observations show winds veering to northwesterly. Dew
points remain in the low/mid 60s, but they will gradually fall
through the evening as cold air advection strengthens. This will
set up a beautiful Friday evening for outdoor activities!
Strong 1020 mb surface high pressure over the Upper Midwest and
northern Great Lakes late this afternoon will build into the
central and southern Great Lakes tonight and Saturday, extending
broad surface ridging down across northern Ohio and northwest
PA. This combined with continued mid/upper troughing across the
Great Lakes and NE US will support a deep northerly flow of
cool, dry Canadian air across the region leading to perfect
weather for August. Lows tonight will fall into the upper
50s/low 60s, with highs in the upper 70s/low 80s Saturday. Far
NW Ohio could touch the mid 80s. The only issue Saturday could
be the return of smoke plumes due to the northerly flow and many
fires still burning in Ontario and Quebec. The latest HRRR
vertically integrated smoke forecast shows elevated smoke plumes
streaming down across the Great Lakes and Ohio Valley tonight
and Saturday, but the consensus is that the thickest smoke will
drift into the NE US. Skies will definitely be smoky across the
region Saturday, but most should stay elevated above the
surface, so kept haze out of the forecast. A few sites may fall
to 6 to 8 mile visibilities at times, but that should be the
worst of it. This will be monitored in case the smoke ends up
thicker or closer to the ground. This has proven to be a tough
forecast this summer.
The pattern will begin to change Saturday night as the mid/upper
trough over the NE US lifts out allowing a compact shortwave to
approach from the Midwest. This shortwave and support from a
50-60 knot H3 jet streak will generate a surface low over the
Mid Mississippi Valley Saturday afternoon that will drift toward
the Ohio Valley Saturday night. The latest NAM and RAP are
trending faster with this shortwave and associated surface low,
with strengthening warm/moist advection and isentropic ascent
generating a few showers and thunderstorms ahead of a lifting
warm front Saturday night across Indiana. However, the broad
surface high will be slow to shift into the eastern Great Lakes
and New England, so abundant dry air will remain Saturday night.
This makes me think that guidance is too fast to bring precip
into NW Ohio, with most falling as virga, so introduced some
PoPs in NW Ohio after 10Z, but kept them slight chance. Cloud
cover will increase everywhere through the night though, and
with warm air advection, expect lows to stay a bit milder with
low/mid 60s in NW and north central Ohio. NE Ohio and NW PA will
still fall into the upper 50s since the clouds will be slower to
move in there.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
The main item for the short term forecast is that the Sunday and
Sunday night forecast has been altered a bit from previous runs.
There is more confidence in a signal of a weak low moving through
the region on Sunday bringing some scattered rain chances across the
area and have modified the forecast from dry to having some low
chance PoPs. If this feature does occur, this will likely taper down
rain chances on Sunday night slightly with a worked over atmosphere
and some brief subsidence ahead of Monday`s low and cold front.
Therefore, have some lesser PoPs on Sunday night, down to about a
50/50 chance. There is still some chance for severe weather on
Sunday, but the multiple rounds could taper the instability, but
there is enough in place with the supporting upper flow to allow for
some stronger storms. The Monday forecast remains the same with
likely and categorical PoPs with an advancing low pressure system
and cold front moving through the region. Temperatures should be
seaonable on Sunday but cooler with the rain on Monday.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
Quieter weather should be returning to the region for Tuesday and
the first half of Wednesday as high pressure should enter from the
south as a brief upper ridge will move overhead. Temperatures on
Tuesday should be a touch below normal behind Monday`s cold front
and a few areas will likely touch 80 degrees but believe that a
large chunk of the area will stay in the upper 70s. Temperatures
will improve toward normal on Wednesday. For Wednesday night and
beyond, the pattern will trend back toward unsettled as an upper
trough will enter the region and a surface low will enter, bringing
additional chances for showers and thunderstorms for later in the
week. Have some generic chances for now and temperatures near
normal.
&&
.AVIATION /00Z Saturday THROUGH Wednesday/...
VFR at the terminals with the exception of YNG with the
possibility of MVFR BR after 09Z tonight through early dawn
hours Saturday. Fog formation, or low IFR stratus formation is
more likely further east in NW PA not including ERI, and this
could spread westward into YNG late tonight. Winds becoming east
northeast less than 12kts. SCT cumulus around 3-4kft expected
Saturday during afternoon heating. Otherwise, mainly high clouds
in the forecast.
Outlook...Non-VFR in showers and thunderstorms likely Sunday
afternoon through Monday. Isolated to scattered showers and
thunderstorms are possible again Tuesday.
&&
.MARINE...
High pressure entering from the north will allow for northerly winds
to be favored through tonight. A slightly enhanced pressure gradient
tonight could allow for some strong north to northeast winds tonight
to 15 knots. Flow will shift to more easterly flow for Saturday and
waves will increase a bit over the western basin, but well below any
headline criteria. A weak low pressure system appears to enter the
region on Sunday and will shift flow to offshore on Sunday
afternoon. A stronger low and cold front will move through the
region on Monday and stronger southwest flow will be favored across
the lake during the day before shifting more westerly for Monday
night into Tuesday. West flow will continue into Tuesday but weaken
with approaching high pressure. There are some opportunities for
Small Craft Advisory worthy headlines on Monday and Tuesday with the
systems moving through the region.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...None.
PA...None.
MARINE...None.
&&
$$
SYNOPSIS...Garuckas
NEAR TERM...Garuckas/26
SHORT TERM...Sefcovic
LONG TERM...Sefcovic
AVIATION...26
MARINE...Sefcovic
Area Forecast Discussion
National Weather Service Dodge City KS
817 PM CDT Fri Aug 4 2023
.UPDATE...
Issued at 817 PM CDT Fri Aug 4 2023
Radar and infrared satellite imagery at 8 pm showed a linear
complex of strong to severe thunderstorms entering far NW Kansas.
Earlier convection in eastern Colorado had dissipated, presumably
due to strong capping and lack of forcing. Mesoanalysis depicted
strong instability and bulk shear across western Kansas and
eastern Colorado, with correspondingly high MCS maintenance, but
confidence is low on when and where additional convective
initiation will occur tonight, given lack of forcing and strong
capping, capping that will only get stronger after sunset. NW KS
complex has developed a decided SEly component of motion, and it
will approach the northeast zones tonight. Trimmed pops to slight
chance (<25%) through sunrise, with low confidence on convective
evolution and placement, but current trends support highest
chances northeast. Temperatures and winds are on track with
previous forecast, and no other changes planned. Short term grids
suggest a heat advisory may be required adjacent to Oklahoma
Saturday afternoon.
&&
.SHORT TERM...(This evening through Saturday night)
Issued at 143 PM CDT Fri Aug 4 2023
Water vapor satellite imagery and RAP upper air analysis at midday
indicates roughly zonal flow across the central plains between a
rather flat subtropical ridge spread out over the southern plains
and northern Mexico and weak troughing over the northern plains
and the Pacific Northwest. Latest ensemble and deterministic
guidance suggests this pattern will change little over the short
term period as the subtropical ridge slowly retrogrades and the
trough intensifies over the northern plains before digging
southeast into the Midwest Saturday afternoon/evening. In the
absence of any noteworthy synoptic forcing, 850-mb temperatures
will continue to decrease, allowing the cooling trend to continue
for southwest KS with afternoon highs today in the low to mid
90s.
Later this afternoon and evening, typical summertime thunderstorm
initiation is expected over the front range of eastern CO,
spreading east with time. The CAPE/shear parameter space will be
supportive of severe convection, with supercellular storm mode
expected initially before transitioning to linear/outflow-
dominant mode owing to weak low-level shear as they approach our
area. Weak synoptic lift will likely limit convective coverage,
and latest CAMs cast doubt on the degree of thunderstorm activity
that makes it to western KS. However, any storm that does reach
our area will carry with it a marginal severe hail/wind gust
threat. Otherwise, the majority of southwest KS will remain dry
overnight, with lows dropping into the mid 60s to low 70s.
Daytime Saturday, a brief pause in the cooling trend is forecast
as guidance agrees 850-mb temperatures will tick up a few degrees,
fostering afternoon highs in the mid to perhaps upper 90s.
Thankfully, the aforementioned strengthening and digging upper
level trough will send a cold front southward through the area
which will reinvigorate the cooling trend. Ahead of this boundary,
southeasterly upslope flow in eastern CO will once again promote
thunderstorm development that will translate east with time, and
given a relatively strong upper trough supplying adequate
forcing, confidence in convective coverage is much higher. MLCAPE
in the 1000-1500 J/Kg range amidst 45-55 kts of deep-layer shear
will result in supercells being the initial storm mode. As usual
during the summer, weak low-level shear will cause upscale
growth, but where and when this occurs is still somewhat
uncertain. Reasonable agreement amongst CAMs suggests convection
will be in the process of merging around the time they cross the
KS/CO border, leading to damaging wind gusts, some potentially
significant, becoming the primary threat. That said, any discrete
or semi-discrete thunderstorm will still be capable of severe
hail. This severe MCS will track through southwest KS during the
evening into the overnight hours, exiting our area before sunrise
with lows in the 60s.
.LONG TERM...(Sunday through Friday)
Issued at 234 PM CDT Fri Aug 4 2023
Key Messages: Well below normal temperatures to begin the long
term period, and then near or just below normal temperatures
through the remainder of the week. Above normal precipitation is
also expected as the subtropical ridge stays well southwest of the
central plains.
Showers and thunderstorms may be ongoing at the beginning of the
long term period as they linger in the wake of the overnight MCS,
however any activity should vacate the area quickly. Gusty
northerly winds will be the story Sunday morning behind the cold
frontal passage, but will be gradually weakening through the day
as surface high pressure builds into the central plains. This cold
advection will be a welcome change to the intense heat southwest
KS has been mired in for a while now, and afternoon highs will
only reach the mid to upper 80s. Another round of late afternoon
or evening thunderstorms is possible favoring the western zones as
post-frontal upslope flow triggers convection over the Rockies,
however confidence in this scenario is low given DNVA behind the
departing upper trough.
Below-normal temperatures will continue Monday as 1000-500-mb
thicknesses decrease further, with afternoon highs again in the
mid to upper 80s. However, medium range ensembles indicate a
return to normal or just below normal temperatures will occur as
the synoptic pattern remains largely static through the end of the
period. That said, west-northwesterly mid-level flow will foster
plenty of precipitation opportunities owing to a series of
shortwave troughs digging east-southeast through the plains from
the northwest CONUS, although based on latest ensemble meteograms,
these will be more likely Monday-Wednesday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 431 PM CDT Fri Aug 4 2023
VFR will continue through this TAF cycle with light winds,
providing good flying weather outside of any convection. At least
isolated convection is suggested by 12z NAM/ARW during the
06-12z Sat time frame, but with models in poor agreement on
placement, and whether storms will even survive coming out of
Colorado, opted to leave this set of TAFs largely dry. VFR will
continue Saturday with varied amounts of cirrus and continued
light winds. Much higher confidence in convective impacts to
aviation just beyond this TAF period, 00-06z Sun. Some storms
Saturday evening will likely produce strong outflow wind gusts to
near 50 kts.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 68 96 63 86 / 20 40 60 0
GCK 67 93 62 84 / 20 30 50 0
EHA 65 98 61 83 / 20 30 30 0
LBL 68 98 63 84 / 20 40 50 0
HYS 66 92 63 86 / 20 40 60 10
P28 71 97 67 88 / 20 40 70 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Turner
SHORT TERM...Springer
LONG TERM...Springer
AVIATION...Turner
AREA FORECAST DISCUSSION
National Weather Service Kansas City/Pleasant Hill MO
623 PM CDT Fri Aug 4 2023
.Discussion...
Issued at 345 PM CDT FRI AUG 4 2023
Key Messages:
- Strong to Severe Storms This Evening
- Thunderstorms Saturday Late Afternoon Through Late Evening; Severe
Storms Possible
- Slightly Cooler Temperatures; Still Hot and Humid
Discussion:
The series of mid-level troughs across the Canadian Prairie
Provinces has de-amplified the H5 ridge pattern across the area
providing mostly zonal flow. However, there are still multiple vort
maxes and short-wave perturbations riding through the flow that will
interact with a high theta-e airmass at the surface as well as
surface thermal boundary that appears to be located roughly along
the Interstate 70 corridor, perhaps just a tad south of it. There is
also a stalled out surface cyclone across the central and southern
Great Plains with surface troughing extending eastward into Central
Missouri. With weaker flow in the southern Great Plains where there
is still 594dam high pressure, there is not much flow to help steer
this broad surface low pressure system. The main feature to monitor
this morning and afternoon is the MCV associated with last night`s
convective activity in eastern Nebraska and northeast Kansas. While
the initial convection with this feature has dissipated, additional
development has started around 19z. Most of these showers have been
focused along Hwy. 36 and northward, though a few smaller cells
quickly popped on radar in southern reaches of the forecast area. It
appears this MCV has provided a convective feedback, with a short-
wave trough axis and compact vort max at 500mb centered around the
NE-IA-MO-KS borders. This is creating a favorable kinematic
environment for thunderstorm develop from the KC Metro and eastward
into Central Missouri. While the current hodographs do not have a
well defined shape just yet, 0-6km bulk shear values have increased
to around 30-35 kts across the region. With the surface boundary
along interstate 70 and the surface troughing extending from the
cyclone over the central/southern plains, the weak surface winds
have backed in the last few hours across the area. Further,
southwesterly winds between 800-750mb has brought in slightly drier
air out of the Southern High Plains, and this has resulted in
clearing skies through this afternoon. The afternoon insolation has
allowed MLCAPE to reach around 2500 J/kg, which is close to what the
HREF had been hinting for this afternoon since its run last night.
While a capping inversion remains just about 850mb, the increasing
kinematics and convergence in the vicinity of the MCV has good
potential to work through this cap as we head into the early
evening. Further, it appears the MCV has also provided a modest
amount of mid-level cooling, which is helping the mid-level lapse
rates approach 7.0 C/km, and the RAP is catching onto this trend as
noted in point soundings throughout eastern Kansas over to Central
Missouri. This is a substantial improvement compared to lapse rates
from yesterday afternoon. With further boundary layer
destabilization late this afternoon, the thermodynamic improvements
may foster stronger updraft development. The main question is how
updrafts will tap into the shear environment. While the backing
surface winds have provided notable curvature in the lowest 1km and
even 2km of the hodograph, RAP and HRRR hodographs are not
demonstrating much curvature above 3km. Therefore, it may be
difficult for discrete convection to maintain itself, given that
overall storm-relative flows will be weaker, and may result in
narrow updrafts. Therefore, in order for convection to last longer
in this environment, currently think multi-cell clusters would need
to congeal and form a stronger cold pool to maintain itself. As for
severe thunderstorms hazards, precipitation loading may help to
increase low-level vertical pressure gradient forces that can result
in damaging winds. With deeper updrafts, severe hail is also
possible. Given the humid surface airmass and deeper warm cloud
depths, hail stones likely would experience a lot of melting before
reaching the ground. But enhancing kinematics may help to counter
this and result in larger hail stones. As for the tornado threat,
this is very conditional. While the low-level hodograph curvature is
there, considering the hodograph as a whole, the streamwise
vorticity ingest looks to be confined over a very shallow layer,
then quickly becomes more crosswise above 2km. Throughout most of
the environment, 0-1km SRH values are around 100 m^2/s^2 for
rightward deviations from the mean flow. Perhaps the surface
boundary could provide localized enhancements if a discrete storm
develops close to it. As mentioned before, while bulk shear values
are increasing with the H5 height falls in the vicinity of the MCV,
it is not equally distributed, with most of the shear below 3km.
Therefore, discrete storms may not have the support to remain
discrete, despite the elevated bulk shear values. An inability to
maintain discrete supercells also limits the tornado threat. If
multi-cells develop and congeal into a bigger thunderstorm cluster,
we will need to monitor the leading edge`s orientation to the 0-3km
bulk shear vector, which will have a magnitude around 35 kts. If
this becomes perpendicular, there may be enough destabilization this
afternoon increasing the 0-3km CAPE that could support mesovortex
generation. However, for areas close to the current MCV, these
vectors are oriented parallel to how cells would form and congeal,
and thus greatly limits this potential.
For those of you looking at the HRRR runs this afternoon and perhaps
viewing the 12z HREF, you probably did notice the stronger updraft
helicity (UH) tracks associated with the HRRRs most intense
convection (based on simulated reflectivity). Given the the
increasing shear within the first 0-3km and curvature in this layer,
coupled with the potential for strong updrafts with improving
thermodynamics, it is not a surprise to see CAMs generating these
kinds of tracks. However, keep in mind the discussion above about
how the overall deep layer shear environment may struggle to
maintain supercell structure for an extended period of time. With
the current environment, discrete convection would likely need to
latch onto the thermal boundary to develop and sustain robust
updraft helicity. This certainly highlights the potential for
strong, potent updrafts to develop, but does not necessarily tell the
whole story about tornado potential. Therefore, damaging winds and
hail remain the primary threats with convection this afternoon, and
the tornado threat conditional.
CAM guidance suggests that this wave moves out of the area between
02-05z, and subtle H5 rises behind the short-wave provide weak
subsidence and dry conditions out. The bulk of the CAMs have no
shower or storm activity during the morning and early afternoon
hours on Saturday. However, there are a few hints of some light
activity from a few of the coarser synoptic scale models. Given the
airmass with 70 to 75 degree dewpoints, a stalled surface low,
thermal boundary, and potential for lingering outflow, will leave
slight chance POPs for most of the morning and afternoon hours on
Saturday. During the morning and early afternoon, would not expect
anything considerably organized. However, a stronger H5 trough and
with moderately strong vort max is progged to eject out of the High
Plains late in the afternoon and move eastward toward the forecast
area. This will provide another round showers and thunderstorms late
Saturday Night, and likely into the overnight hours. Assuming the
boundary layer is able to recover from Friday activity, SBCAPE mean
values from the HREF are progged around 2500 J/kg, with MUCAPE
values into the late evening hours between 2500-3000 J/kg. Deep
layer shear will increase again with 0-6km values around 35 kts
ahead of the main H5 short-wave. With a stronger jet streak
developing, the hodographs over the deep layers may have the
potential to have a more defined shape to them. These favorable
kinematics will move over a favorable airmass again, with dewpoints
still in the lower to mid 70s across most of the area. CAM guidance
still continues to keep the surface troughing in place with the
surface thermal boundary somewhere in the state. Would expect the
location of this boundary to change somewhat if Friday`s activity
releases a stronger outflow. However stronger differential heating
along the boundary could steadily increase convergence throughout
the late afternoon and evening hours of Saturday. Damaging winds and
hail will be the primary threat. With increasing low-level jet
throughout the day, storms over the Plains likely congeal leading to
some form of an MCS by the time it reaches our area. Therefore, even
with decent low-level curvature, not sure that Saturday`s activity
presents tornadic threat, though that could change depending on the
behavior of Friday activity.
For the rest of the week, mid-level flow will be quasi-zonal which
will help keep temperatures closer to climatological normals for
this time of year. We should start to see a decrease in humidity as
well. A few vort maxes likely become embedded within the zonal flow
bringing periodic chances for showers/convection through the middle
of the next work week.
&&
.Aviation...(For the 00Z TAFS through 00Z Saturday Evening)
Issued at 620 PM CDT FRI AUG 4 2023
Thunderstorms have developed but pushed eastward away from the KC
Metro terminals. For now, a few VFR clouds are behind the boundary
that was produced for those storms. Increasing cloud cover
overnight will drop to MVFR. With the increase moisture content
and calm winds, patchy fog is possible tonight. Have placed MVFR
visibility into most of the TAFs, with IFR at STJ that sits in the
River Valley. Additional shower/storm activity is possible
Saturday night but is outside the current TAF period.
&&
.Hydrology...
Issued at 345 PM CDT FRI AUG 4 2023
A Flood Watch has been issued for eastern portions of the forecast
area this evening through 15z Saturday morning. This is the area
that has seen multiple rounds of heavy rain throughout the week.
HREF probability matched mean values indicate QPF potential for 2-4
inches east of Hwy. 65, with localized pockets of 5 inches. While
these higher amounts likely will not spread the entire area,
training storms along the boundary and slow storm motions, coupled
with deeper warm cloud processes will support higher rain rates. For
areas in our east, 1 and 3 hour flash flood guidance is around 2
inches. Efficient thunderstorms will be able to produce this.
Therefore, the flood watch has been issued. Expect rises on local
creeks and streams. West of the flood watch area, rainfall amounts
between 0.50 and 2.0 inches are possible. These areas have flash
flood guidance closer to 3 inches over 3 hours, thus will take a
little bit more for flooding issues to occur. While the CAMs have
struggled with QPF over the last few days, the probability matched
mean magnitudes have been reasonably close estimates though not
always progged in the exact spot. Will also quickly mention that non
CAM ensembles, such as the GEFS maintain relatively low
probabilities for QPF this evening and into early Saturday morning.
For example, GEFS probability for exceeding 1.0 inch of QPF in our
east is less than 20 percent. However, it does not appear the non
CAM models are picking up well on the MCV, thus, even with their
struggles, leaning more toward CAM trends for QPF and flooding
potential as these are at least attempting to resolve the MCV.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...Heat Advisory until 8 PM CDT this evening for KSZ057-060.
MO...Heat Advisory until 8 PM CDT this evening for MOZ053.
Flood Watch through Saturday morning for MOZ007-008-016-017-024-
025-032-033-039-040-046.
&&
$$
Discussion...Krull
Aviation...Krull
Hydrology...Krull
AREA FORECAST DISCUSSION
National Weather Service Hastings NE
707 PM CDT Fri Aug 4 2023
.UPDATE...
Issued at 652 PM CDT Fri Aug 4 2023
Updating the forecast to increase thunderstorm chances across
western zones as thunderstorms to the west of North Platte should
continue to slide east and will likely reach at least our western
zones prior to dieing out. These storms will likely weaken and die
out later tonight somewhere over our central or eastern zones.
The most recent 22Z HRRR run is holding the storms together long
enough to at least reach the Tri-Cities after 10 PM CDT.
&&
...Aviation Update...
.DISCUSSION...(This evening through Friday)
Issued at 355 PM CDT Fri Aug 4 2023
Key Messages:
* A few strong to severe storms will be possible across the area
later this evening/overnight, as a complex slides in from
western Nebraska. The main chances for severe storm look to
favor western locations, which is included in the SPC Day 1
Slight Risk area. Large hail, damaging wind gusts and heavy rain
would be the primary threats.
* The passage of the main upper level system through the
Northern/Central Plains on Saturday will push a surface cold
front south through the area. This front will help provide a
focus for afternoon-evening thunderstorm development, and some
may be strong-severe. All but extreme western spots are included
in the SPC Day 2 Slight Risk area. Again...large hail, damaging
wind gusts and heavy rain would be the primary threats.
* In the wake of this upper level system/surface front, a cooler,
but breezy/windy Sunday is in store. Northwest winds with speeds
of 20-25 MPH and higher gusts are expected...and after highs in
the 80s/90s for Thursday, highs on Sunday drop into the mid
70s-low 80s. High temperatures look to remain generally below
normal into the work week.
Currently...
Overall it`s been a pretty quiet day across the area, any
lingering spotty precip has tapered off and sky cover continues
to gradually diminish. Aloft, upper air and satellite data show
generally westerly flow remaining in place, as we sit between one
shortwave disturbance sliding east into IA, with another making
its way through WY and into the western Dakotas. The surface
pattern remains pretty weak across the CWA, set up between sfc
boundaries to our north, south and west. Winds throughout the day
have been light and variable. By the time the day is over,
forecast highs will have worked out pretty well...at 3 PM obs
range from the upper 70s to mid 80s.
Tonight through the weekend...
Seeing more thunderstorm activity to our west over higher terrain
and near the sfc boundary late this afternoon...and its evolution
will be the primary focus as we get into this evening and
overnight. Models are in pretty good agreement showing a
developing complex sliding ESE through western NE and at least
making it to our western CWA...but then ideas diverge with how
things evolve overnight. Hi- res models suggest activity becomes
less organized as it pushes east through the area (show the better
instability axis mainly along/outside the southern/western
portions of the CWA), with the potential for some other activity
developing along the nose of an overall weaker LLJ. The better
potential for strong/severe storms continues to be across western
portions of the CWA, where a SPC Slight Risk remains...the
remainder of the CWA outside the extreme NE corner is included in
the Marginal Risk area. Large hail/winds and heavy rain would be
the primary hazards with the strongest storms.
As we get into Saturday, the story lies with the continued
eastward progress of the main upper level system across the
Northern/Central Plains and the accompanying surface cold front.
Confidence in how much precipitation lingers on into the daytime
hours on Saturday is not high...there are differences between
models, so didn`t feel comfortable completely removing PoPs during
the day for any particular area...but feel that overall it`ll be
on the drier side for most. Later in the day and into the evening
hours, the focus then turns to that sfc boundary and whether
storms fire along it, and if so, how much. Uncertainties in the
timing/location of the front continues due to model differences,
so overall confidence is not high. Some models show that outside
activity clipping far northern/southern portions of the area,
little else impacts the CWA along that front...then as we get into
the overnight hours, main precip chances focus across northern
areas as the main upper system moves through. For storms that do
develop during the afternoon/evening hours, models are in fairly
decent agreement showing at least 2000 j/kg of CAPE to work with
(with highs in the 80s/90s and 60s/70s dewpoints) and 30+kts of
deeper layer shear...so strong/severe storms will be a concern.
All but extreme western portions of the CWA are included in the
Day 2 Slight Risk area...large hail/damaging winds/heavy rain
would be the primary threats.
Outside of any lingering precip across NErn portions of the CWA
mainly in the morning hours, the forecast for Sunday is dry. In
the wake of the upper level system and sfc cold front, a
breezy/windy day is expected...a tighter pressure gradient is
expected across the region, with a corridor of stronger winds
aloft tap into. NW winds with sustained speeds around 20-25 MPH
and higher gusts is expected...with gradual diminishment late in
the day/evening. Along with the winds, cooler temps are
expected...going from the 80s/90s on Saturday to highs in the mid
70s-low 80s. Normal highs this time of year are in the mid 80s-low
90s.
Monday and on...
Looking toward the new work week, overall there were no notable
changes in the forecast. Models continue to show zonal to low-
amplitude northwesterly upper level flow in place across the
region...and there will be the potential for periodic embedded
shortwave disturbances to bring shower/storm chances to the area.
Confidence in any timing/location/coverage details is pretty low
at this point. Highs in the 70s-low 80s stick around into Monday,
then climb further into the 80s/near 90 by mid-week.
&&
.AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Sunday)
Issued at 652 PM CDT Fri Aug 4 2023
The primary aviation update was to include the possibility for
thunderstorms at our TAF sites mainly after 10 or 11 PM CDT this
evening. Forecast models are now more aggressive with holding
thunderstorms together long enough for them to reach our TAF
sites. However, thunderstorms are also expected to be weakening
by the time they reach KEAR and KGRI. There is still some
uncertainty as to whether or not these storms will make it far
enough east to reach our TAF sites but the possibility is now
high enough to at least mention a vicinity thunderstorm in the
TAF. The wind should be more out of a westerly direction behind
the outflow associated with these thunderstorms.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...Wesely
DISCUSSION...ADP
AVIATION...Wesely
Area Forecast Discussion
National Weather Service Grand Junction CO
542 PM MDT Fri Aug 4 2023
.SHORT TERM...(Tonight through Saturday night)
Issued at 147 PM MDT Fri Aug 4 2023
A few showers and storms have fired over the eastern Uintas and
Bookcliffs this afternoon but the strength and coverage is
noticeably less than seen over the past few days. This is all due
to high pressure to our south that continues to build westward and
widespread zonal flow that has setup across the CWA. These two
factors have ended the monsoonal surge that we experienced for
much of the week. Higher PWATs do remain over the northern half
of the CWA which is exactly where the convection has fired this
afternoon. CAM guidance is also picking up on this activity with
the HRRR exclusively keeping convection up north with the NAMNEST
highlighting some very weak returns up north and south. Outside
of the convection, look for partly cloudy skies (a bit more over
the mountains) and the more usual afternoon breezes of 20 to 25
mph...maybe a bit higher in some spots. Overnight, the NBM and
HRRR are picking up on a very subtle wiggle in the flow that might
fire off a quick shower/storm along the Bookcliffs though most
areas will see plenty of starry skies.
Saturday, the jet stream will ride up and over the ridge of high
pressure setting up on top of the CWA. As we`ll be under the left
exit region of the jet, some divergence aloft along with some weak
QG lift will lend themselves to allow another round of
afternoon/evening convection to fire. However, this convection
will be of the more `typical` mid-summer type convection as
moisture content drops to our more normal values. Favored areas
will continue to be along the Bookcliffs northward. With the jet
above us, some deeper mixing will allow another afternoon of some
gusty winds...25 to 30 mph, favoring the southern half of the CWA.
Temperatures will rebound to around 5 degrees above more usual
early August values.
.LONG TERM...(Sunday through Friday)
Issued at 147 PM MDT Fri Aug 4 2023
The synoptic pattern Sunday continues with the Gulf of Alaska low
firmly in place, high pressure camped out over the Desert Southwest
and the Hudson Bay Low with a longwave trough extending south over
the Eastern States. The one caveat to allow to break down this
normally stable pattern is the jet over the Great Basin extending
east across Colorado and out onto the Plains preventing a ridge
building over the Western States. The jet continues to cut east
across the Plains Monday and Tuesday to eject the longwave trough
out over the Atlantic by Wednesday. With this, the high pressure
to the southwest is drawn east over Texas on the tail of the jet
to reopen the door to subtropical moisture to move north into the
Great Basin and into eastern Utah and western Colorado.
With the above synoptic pattern, we will see warm temperatures three
to five degrees above normal with a very dry airmass over the region
Sunday in the zonal flow aloft and gusty west winds as the jet mixes
down to the surface. This will produce near critical fire weather
conditions generally along and south of the I-70 corridor Sunday.
Confidence is low at this time on the timing, location and severity
of these conditions and thus are holding off on issuing fire weather
highlights until tomorrow; stay tuned for updates. These near
critical fire weather conditions will continue Monday, spreading
north into the Uinta and Yampa Basins Tuesday and Wednesday; again
stay tuned for updates on any fire weather highlights.
The high pressure to the south will begin to shift to the east
Tuesday reaching Texas by Friday, allowing monsoonal moisture to
once again move north through Arizona into the region. By Thursday
dew points and chances for showers and thunderstorms will start
increasing leading to a second monsoonal surge. Right now it too
early to tell how strong this surge will be, but we should see some
relief from the dry conditions.
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 542 PM MDT Fri Aug 4 2023
Isolated storms will linger mainly over the eastern Uintas and
eastern San Juans through sunset before dissipating. Breezy winds
will also subside by sunset with clearing skies and light, terrain
driven winds overnight. Expect some cumulus to develop over the
ridges with breezy afternoon winds in most areas Saturday
afternoon, but drier air and high pressure will limit convection
to isolated coverage over mainly the northern higher terrain.
&&
.FIRE WEATHER...
Issued at 147 PM MDT Fri Aug 4 2023
As dry air returns to southern portions of the area, and deeper
mixing brings some gusty winds to the surface, critical fire
weather conditions move back into the picture. On Saturday, models
continue to highlight some localized critical fire conditions for
our southern fire zones but as they will be localized, no fire
weather products appear needed. On Sunday, models continue to
indicate more widespread critical fire weather conditions so
confidence continues to increase for some possible fire weather
products. Debated on issuing a Fire Weather Watch for Sunday
afternoon but another model run should help to nail down the
specifics. These conditions look to occur for much of next week.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...None.
UT...None.
&&
$$
SHORT TERM...TGR
LONG TERM...DB
AVIATION...MDA
FIRE WEATHER...TGR
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
928 PM EDT Fri Aug 4 2023
.SYNOPSIS...
Shower and thunderstorm coverage will be very isolated late this
afternoon and again on Saturday as drier air spills into the region.
Temperatures gradually warm heading into the weekend. Shower and
thunderstorm chances then increase Sunday into Sunday night as a
warm front lifts north across the area. A cold front then tracks
across the region on Monday, resulting in widespread showers and
thunderstorms with a potential for some severe weather. The
forecast becomes muddier later in the week, with a low-confidence
forecast for Tuesday and beyond.
&&
.NEAR TERM /THROUGH SATURDAY/...
900 PM Update...The fcst remains in good shape this evening and made
only minor tweaks to the grids. Shower activity has waned due to
loss of heating and dont anticipate much if any re-development
overnight with lack of triggers and layered dry air pushing in from
the northwest. Expect decent rad cooling tonight and a fog threat
shud mainly impact the NC mtns and east along the I-40 corridor.
Some locales could see patchy dense fog before and thru daybreak.
As of 215 pm EDT: Despite deeper-layer drying and northerly boundary
layer winds in profiles today, surface dewpoints have managed to
hold in the lower 70s this afternoon. This appears to be due to
lingering near-surface moisture from the recent heavy rainfall. The
latest SBCAPE analysis depicts widespread 1500 to 2000 J/kg values
across the region, with the HRRR developing isolated coverage near
the escarpment area, another locus running out near CLT, and then
late day activity trying to make a run east from AL/TN toward the SW
NC mountains and NE GA. Weak lapse rates aloft and limited shear in
profiles will curb any strong to severe thunderstorm potential this
afternoon. Any coverage that manages to develop should diminish
fairly quickly with the loss of heating this evening, but isolated
showers may persist the longest in the Upper Savannah River region
where boundary layer convergence and better moisture lingers. The
near-surface moisture will then lead to some low stratus and fog
redevelopment overnight, with the best chances in the mountain river
valleys and also east of the I-77 corridor.
Conditions look even drier for Saturday, but light southerly
boundary layer flow in the afternoon may contribute to some forcing
near the southern escarpment area. Will advertise isolated
thunderstorms there. Otherwise, expect better insolation with
temperatures recovering another degree or two in most locations over
Friday maxes.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
As of 154 PM EDT Friday: Not too much change to Sunday`s forecast,
which continues to look rather banal in light of only modest
thermodynamics. The upper pattern will have flattened out nicely by
Saturday night, resulting lax flow aloft that will persist through
much of Sunday. At the surface, activation of a weak warm frontal
boundary will allow for SSW winds to develop across the Carolinas
around daybreak, and this will permit some dewpoint recovery by the
afternoon hours. Thus, most guidance does depict some convection
during the afternoon hours, but with minimal shear and the front
already to the north by then, there won`t be much dynamical forcing
to really incite any severe concerns. Ideally, severe risk will
remain minimal with some isolated heavy rainfall the bigger issue
as slow-moving, moisture-rich storms develop through the evening.
Even this will be hampered by poor coverage if the GFS / CMC
solutions pan out. An alternative scenario portrayed by this
morning`s NAMnest (which despite its reputation as a drama queen
has absolutely nailed a few convective events in the last month or
two) is that the remnants of an upstream MCS over the Ohio Valley
may make it into the NC mountains late Sunday evening. Were this
to take place, the severe risk might be increased. For now, SPC`s
Marginal Risk for Severe Weather over the western NC mountains seems
reasonable. Temperatures on Sunday will be right around normal.
Monday remains the bigger weather day as it stands now. Moisture
will continue to stream into the forecast area Sunday night and
the first part of Monday, such that the environment will be a
delicious pea soup (if you`re a thunderstorm, and also like pea
soup) by early afternoon. The 12z model suite is in fairly tight
agreement that a trough axis and associated 500mb speed max will
cross the Tennessee Valley early Monday, entering the Carolinas by
early/mid afternoon. Some 1500-2000 J/kg sbCAPE will be allowed
to develop per most guidance, with all the global ensembles
predicting 75-80% odds of at least 1500 J/kg across basically
the entire forecast area. Associated with the speed max, a plume
of 25-30kt deep layer shear values will develop, resulting in an
increased severe risk for Monday. As it stands now, the primary
threats would appear to be damaging winds by virtue of excellent
DCAPE and perhaps large hail...with the environment looking far
less conducive to tornadic development. PWs in excess of 1.8-1.9"
should make these storms excellent rain-producers...but storm motion
should be quick enough to inhibit a larger threat of flooding rain.
Monday`s temperatures should be near or a few degrees above normal.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
As of 209 PM EDT Friday: Following the passage of a cold front
Monday night and the end of any severe weather, drier air will
push into the northern part of the forecast area as the front
stalls somewhere over South Carolina. Models struggle to come
to anything resembling a consensus for the rest of the week,
as a dynamic but difficult-to-pin-down upper pattern develops.
The stalled front to our south still looks like it may result in
some weak triggering of convection, with better thunder chances to
be had on its south side...and more stable conditions to the north.
But, ensemble forecasts of where exactly that front will set up run
the gamut from "somewhere in North Carolina" to "somewhere in South
Carolina" to "what front?" and there`s no clear majority opinion.
So, for now, the best summary of the mid/late week forecast is
diurnal convection (finally what you`d expect in August)...but it`s
safe to say that some afternoons will be more suppressed, some
more enhanced. Figuring out which will be which at this point?
Hopeless. Ah, the plight of the meteorologist.
&&
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
At KCLT and elsewhere: Light flow continues across the area this
evening with more n/ly winds over NC and se/ly across the Upstate.
Pretty good rad cooling anticipated overnight and the NC mtn valleys
and fthills have the better signal for possible fg/br development.
So, have included MVFR VSBY mention at both KAVL and KHKY before
daybreak. Broad hipres encompassing the area during the day Sat will
continue light sfc flow generally favoring ne/ly outside the mtn
valleys and nw/ly at KAVL.
Outlook: Scattered, diurnal convection is expected to return by
Sunday afternoon, with an uptick in coverage Monday into Tuesday as
a cold front arrives from the northwest. The boundary could stall
just southeast of the area through mid-week. Daybreak restrictions
will be possible each day, especially in the mountain river valleys.
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...None.
NC...None.
SC...None.
&&
$$
SYNOPSIS...MPR
NEAR TERM...HG/SBK
SHORT TERM...MPR
LONG TERM...MPR
AVIATION...SBK
Area Forecast Discussion
National Weather Service Gray ME
1121 PM EDT Fri Aug 4 2023
.SYNOPSIS...
Warm and moist air has pushed back into the forecast area south
of the White Mountains and into far southwestern Maine. This
will allow showers and thunderstorms to form through the evening
hours. Repeated rounds of storms will bring a flash flood
threat, while the storms themselves may contain large hail and
damaging winds. The action winds down mainly after 9 PM.
Saturday will bring a drier day with comfortable temperatures.
The weather should continue to be pleasant through early next
week.
&&
.NEAR TERM /UNTIL 8 AM SATURDAY MORNING/...
0315Z Update...
Latest update was to drop SCAs. See marine section below.
0052Z Update...
Latest update was to drop Flood Watches across the region.
Nevertheless, a few heavy showers and thunderstorms can be
expected through late this evening.
0025Z Update...
Latest update was to allow the Severe Thunderstorm Watch
Expire. Otherwise, only minor cosmetic changes to the near term
portion of the forecast.
Update...
Showers and thunderstorms continue to cross the region this
evening. Plenty of lightning remains over southern New
Hampshire, York County in Maine and off the coast of Maine as of
2230Z. The latest HRRR has the precipitation over southern New
Hampshire consolidating and moving off the coast from Portland
and points south by 02Z.
Will continue with high pops over southern areas into this
evening before the heavy rain, gusty winds, hail diminish
tonight. Made minor adjustments to temperatures, dew points and
winds.
Prev Disc...
A weak warm front is draped across the center of the forecast
area and is providing a focus for all the action at the moment.
A reservoir of MUCAPE around 2000 J/kg is being fed into the
boundary and repeated rounds of showers and storms are forming
along it and drifting east. While the severe threat is non-
zero...it will be isolated and pulse-like with this feature. The
higher risk will be for flooding as repeated rounds of
convection move along this area for the next several hours.
The severe threat will increase later this afternoon and early
evening as the cold front sweeps towards the area. Again the
focus will be along and south of the warm front which should
remain draped along a line from LEB to PWM. Shear is marginal
for significant organization...but moderate CAPE and some
breaks in the overcast may allow for sufficient updraft
acceleration for large hail and damaging winds.
Generally by 8 or 9 PM the bulk of the convection will be moving
east across the waters. The front will likely wait until Sat to
mix down completely...some light winds and plenty of low level
moisture are expected. Patchy fog inland will be possible...but
weakly onshore flow along the coast may allow for some marine
fog/stratus especially north of PWM.
&&
.SHORT TERM /8 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
Offshore flow and drying expected Sat. With weak forcing any
shower activity is likely to be confined to the higher terrain
and will dissipate quickly near sunset. Overnight patchy river
valley fog will be possible...especially where it has rained
recently.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
Overview: Pleasant Summer weather will continue on both Sunday and
much of Monday with mainly dry conditions, low humidity, and near
seasonable temperatures. An area of low pressure with an associated
frontal system will then cross on Tuesday through Tuesday night,
bringing our best potential for widespread showers and perhaps
thunderstorms. Weak high pressure then looks to return for remainder
of the week with just a few isolated showers possible.
Impacts: No major weather related impacts through Monday. Locally
heavy rainfall is then possible on Tuesday. Quieter weather will
then follow to close out the week.
Forecast Details: Quiet and nice Summer weather will continue on
Sunday through much of Monday as sfc high pressure and mid-level
ridging moves across New England before exiting off to the east
Monday night. Skies will be clear to partly cloudy with h850
temperatures hovering around +11C, which supports highs into the
upper 70s to lower 80s. Lows will be comfortably cool as well, into
the 50s to lower 60s.
Clouds will then increase on Monday night with scattered showers
becoming increasingly likely from west to east overnight as a
potential triple point low approaches from the southwest. This will
be associated with a mid-level trough axis, which will result in
increasing southwesterly flow, helping to boost PWATs to near 1.5",
sfc dew points to near 70 by Tuesday, and WAA. This combined with
forcing from the LLJ and associated frontal system will set the
stage for locally heavy rainfall, which given ongoing wet conditions
will need to be monitored. There is also some severe potential
depending on the timing of the frontal passage and available
energy. High temperatures remain uncertain as it will depend on
how far north the warm front makes it but for now would expect
70s to mid- 80s from north to south. Numerous showers and
scattered thunderstorms will continue through early Tuesday
night before a Canadian cold front crosses either late at night
or early Wednesday morning, bringing a return to a drier
airmass.
A cool pool aloft on Wednesday will still allow for a chance for a
few mostly diurnally driven showers and perhaps rumble of thunder
with with highs into the 70s and lower 80s. Weak high pressure then
looks to build over the region for the remainder of the week with
just typical diurnally driven isolated to widely scattered showers
possible and near seasonable temperatures.
&&
.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
Short Term...Weak warm front draped across the center of the
forecast...from roughly LEB to PWM...will be the primary focus
for SHRA/TSRA in the near term...before eventually filling in to
the south as the cold front sweeps thru. I have prevailing or
TEMPO TSRA at all TAF sites along and south of that
boundary...with no thunder to the north. Outside of the local
MVFR or lower in convection...mainly VFR conditions are
occurring. After midnight weakly onshore flow is possible until
the front can mix down westerly winds...and some IFR or lower
marine fog/stratus is possible from PWM north to RKD. Otherwise
river valley fog is likely as skies clear tonight at LEB and
HIE with LIFR conditions. VFR conditions return Sat and most of
the area Sat night. Patchy valley fog will be possible once
again.
Long Term...VFR conditions expected on Sunday except across
northern terminals such as KHIE where upslope flow will result
in MVFR restrictions through the afternoon hours due to SHSN and
low cigs. Northwest winds may gust up to 30-35 kts across all
terminals through early Sunday afternoon before diminishing
Sunday night. VFR conditions are then expected to dominate
through much of next week as high pressure allows for mostly
quiet weather. No LLWS is expected for the entire forecast
period.
&&
.MARINE...
Short Term...Some patchy fog is possible before the front
clears the waters tonight. Otherwise, winds and seas continue
to diminish tonight and remain below SCA thresholds thru Sat
night.
Long Term...Winds and seas expected to remain below SCA
thresholds thru Tue. Ahead of the next approaching system
onshore flow increases. Winds near 25 kt and seas building over
5 ft are possible.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...None.
NH...None.
MARINE...None.
&&
$$
Cannon/Tubbs
Area Forecast Discussion
National Weather Service Northern Indiana
648 PM EDT Fri Aug 4 2023
.SYNOPSIS...
Issued at 317 PM EDT Fri Aug 4 2023
Rain has been introduced to the forecast on Saturday as a
weakening disturbance moves through. Heavy rain is possible. This
may suppress the severe weather risk forecast for Sunday night.
Monitor our website and social media accounts for updates Saturday
morning.
&&
.SHORT TERM...(This Evening through Saturday)
Issued at 317 PM EDT Fri Aug 4 2023
Stable conditions are noted on satellite this afternoon north of US
30; so POPs have been trimmed some. Otherwise, just an isolated
shower or two prior to sunset south of US 30.
New for this forecast period was the introduction of POPs Saturday
as a Mesoscale Convective Vortex ejects from eastern Nebraska this
afternoon, arriving to western Indiana near or after daybreak. How
this feature evolves, mainly its forward speed and how far east it
goes, is uncertain. The north-south extent has some questions as
well with the 15z RAP an outlier favoring a path through central
Indiana. Lingering subsidence will be a negative factor for this MCV
to push east through the whole forecast area, while a lingering
stationary front through central IL and southern IN suggests the MCV
could traverse those areas.
Interpreting all of this results in medium-high confidence in rain
prior to noon EDT west of US-31. Wind speed aloft is generally weak,
30 knots or less through 500 mb, for forward-progress will be slow.
Because of the slow speed, heavy rain may be a concern. It is
certainly possible the next forecast package really needs to ramp-up
the heavy rain risk. Forecast soundings suggest thunder will be
limited; non-existent CAPE and stable lapse rates. POPs will be
limited over northwest Ohio where slow forward progress and
subsistence may limit rain chances there. With the chance of rain
and increased cloud cover, I have nudged high temperatures down 2
degrees as well; a touch closer to a 50th percentile forecast.
&&
.LONG TERM...(Saturday Night through Friday)
Issued at 317 PM EDT Fri Aug 4 2023
Confidence is low for the severe weather risk Sunday night, as is
confidence in the POPs Saturday night through Monday. Saturday`s MCV
might have lingering implications on Sunday`s severe weather risk,
especially if the MCV lingers into Sunday morning. A well organized
upper-level low will dig into the Midwest Sunday afternoon, passing
over the forecast area Sunday night or Monday morning. 12z forecast
guidance has eroded what were favorable severe weather parameters,
according to Roller`s AFD this morning. New parameters are much more
marginal with perhaps a better severe storm risk over central
Indiana. This will need to be revisited tonight.
This trough is forecast to exit by Tuesday, marking a brief return
to dry weather. West or northwest flow aloft through the week will
keep temperatures cool to seasonable, while ushering disturbances
through the Midwest toward the end of the week.
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday Evening)
Issued at 639 PM EDT Fri Aug 4 2023
Winds weaken tonight with loss of diurnal heating while another
opportunity for patchy ground fog toward daybreak, however
confidence once again in exact coverage remains low and have left
any VSBY drops out of the TAF forecast. Have introduced chances of
rain after 19z Saturday for KSBN and 21z for KFWA with a MCS
potentially moving into the area but guidance has struggled at
this time with the systems path, if a more southern trajectory
occurs instead this would lead to a decrease in precipitation
chances. At this time looking at the system moving across north
central IL moving into north central IN.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...Beach Hazards Statement until 4 AM CDT Saturday for INZ103.
MI...Beach Hazards Statement until 5 AM EDT Saturday for MIZ177-277.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...Brown
SHORT TERM...Brown
LONG TERM...Brown
AVIATION...Andersen
Visit us at www.weather.gov/iwx
Follow us on Facebook...Twitter...and YouTube at:
www.facebook.com/NWSNorthernIndiana
www.twitter.com/nwsiwx
www.youtube.com/NWSNorthernIndiana
Area Forecast Discussion
National Weather Service Louisville KY
932 PM EDT Fri Aug 4 2023
.Forecast Update...
Issued at 930 PM EDT Fri Aug 4 2023
Skies are mostly clear of any low-mid layer cloud cover over
southern Indiana and central Kentucky, but we still have a few bands
of high level cirrus overhead from convection to the west. This
period of clearing is expected to cause light patchy fogging, mainly
south of the Kentucky parkways as temperatures drop to the dew point
with calm winds in place. Any cloud cover over an area will reduce
cooling and fogging. Besides the temperatures having to be adjusted
slight to match current conditions, the forecast remains on track.
&&
.Short Term...(This evening through Saturday)
Issued at 310 PM EDT Fri Aug 4 2023
A few isolated showers are lingering over portions of
Logan/Simpson/Allen counties this afternoon, though we should
finally see those diminish in the next 2 hours or so. Kentucky
Mesonet stations reveal a range in max temps so far for today, which
is a result in differing cloud cover and those pockets of showers.
Our northern portions of the forecast area has reached the upper
80s, but across Logan/Simpson, Kentucky Mesonet reports max temps
remaining in the mid 70s.
For tonight, should be another night with a chance for some patchy
fog development, though it will be more patchy and not as dense as
earlier this morning. We`ll see temps drop into the mid to upper 60s
across the region, with calm winds and cirrus keeping us under
partly to mostly cloudy conditions.
For tomorrow, weather again will be mostly dry and warm for the
forecast area as zonal flow moves across the Ohio Valley. However,
another shortwave trough will be riding within the upper flow across
the central Plains, with an associated sfc low tracking across
central IN. This will bring yet another wave of heavy rain and
storms possible across much of the mid-Mississippi River Valley
after several days of intense flooding issues. Similar to the past
few days, the best chances for precip will be just to our west, but
will need to carry a slight chance for mention of isolated showers
and possibly a few storms tomorrow for areas west of I-65, and for
most of the day after 12z.
.Long Term...(Saturday night through Friday)
Issued at 303 PM EDT Fri Aug 4 2023
========================================
Synoptic Overview
========================================
Pattern aloft will start off with a flat ridge across the southwest
US with mainly zonal flow across the Ohio Valley. Models still
agree with a seasonally strong mid-level perturbation moving from
the Midwest into the Great Lakes with an attendant cold front
pushing through our area. This will likely bring a period of active
weather to the region in the form of strong/severe storms. After
the passage of the upper wave, a broad upper trough axis will be
seen across the eastern US to start off the new week. While Mon/Tue
continue to look dry, a couple of stronger perturbations look to
impact the region by Wed/Thu bringing additional rounds of storms to
the region.
========================================
Meteorological Discussion and
Sensible Weather Impacts
========================================
Saturday Night through Sunday Night...
It appears that we may have a bit more convective activity in the
area Saturday night as a small perturbation moves through northern
IL/IN. While the NAM3K isn`t all that bullish, there is good
agreement within the HRRR and ARW models along with the RRFS that a
band of convection may affect the region. Still a bit of difference
in the timing of this convection through the region. Heavy rainfall
and gusty winds will be the main threats with this activity. Lows
Saturday night will be in the upper 60s to the lower 70s.
Heading into Sunday, we`ll be watching the upstream perturbation come
from the Midwest and into the Ohio Valley. Convective evolution
here is a bit muddled as late Saturday night convection coming
through the region could result in a bit more cloud cover which in
turn could result in much less instability. Model soundings show
that if we have some sun, we`ll get decently unstable and the bulk
shear increases throughout the day. It`s possible that we could
have 1 or 2 rounds of storms, with perhaps one Sunday afternoon/eve
and then another along the cold front coming through late Sunday
night. Given the degree of shear and instability, strong/severe
storms will be possible with heavy rainfall and damaging winds being
the main threats. Have gone ahead and lowered temps slightly on
Sunday with highs in the 83-87 degree range. Lows Sunday night
should dip back into the upper 60s to around 70.
Monday through Tuesday Night...
Surface cold front looks to drop southward through the CWA Monday
morning with a risk of some leftover showers across the south on
Monday. An influx of cooler/drier air is expected with highs only
warming into the upper 70s across southern IN and northern KY with
lower 80s across southern KY. Lows Monday night will cool back into
the upper 50s to the lower 60s. Dry weather is expected for Tuesday
and Tuesday night. Highs Tuesday will be in the low-mid 80s with
overnight lows in the upper 50s to the lower 60s.
Wednesday through Friday...
Storm chances look to increase as we get towards the midweek period
as another perturbation within the upper flow pushes through the
region. Probably will see at least some scattered showers Wednesday
afternoon with the typical afternoon heating. Model agreement with
the perturbation coming in late Wed/Thu has increased a bit with
Thursday looking like a potentially active weather day across the
region given the strength of the perturbation and relatively decent
CAPE/shear profile. Cooler and drier weather is expected for Friday
as we will remain in a northwest flow aloft.
Highs on Wednesday will be in the lower to mid 80s with overnight
lows in the upper 60s. Thursday will feature highs in the mid 80s
with overnight lows in the upper 60s to the lower 70s. Highs Friday
will be in be in the mid 80s.
========================================
Forecast Confidence
========================================
Overall confidence in the first half of the long term remains
generally medium-high. Generally low-medium confidence still exists
in the back end of the medium range given the spatial/temporal
differences within the ensemble envelope.
&&
.Aviation...(00Z TAF Issuance)
Issued at 757 PM EDT Fri Aug 4 2023
Most of the region is seeing mostly clear skies with some light
cirrus overhead from convection farther to the west. This clearing
will likely lead to some MVFR fog at BWG as winds are expected to
calm and temperatures hit the dew point. Believe SDF, HNB, and LEX
should remain VFR.
Late tomorrow morning, a north to south oriented line of showers and
storms will move from west to east across the region. The center of
this line is expected to weaken while leaving rain to the north and
south. This could cause the showers/storms to hit or miss BWG.
Because of this uncertainty, left mention out of the TAFs. Believe a
better chance is at HNB and SDF. It`s also possible the first wave
will fade with a second wave developing later and pushing through
during the evening hours.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...None.
KY...None.
&&
$$
Update...KDW
Short Term...CJP
Long Term...MJ
Aviation...KDW
Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
925 PM CDT Fri Aug 4 2023
.UPDATE...
Issued at 924 PM CDT Fri Aug 4 2023
Main focus tonight continues to be on an exceptionally well-
developed/vigorous MCV currently traversing northern Missouri.
Unfortunately, the circulation and associated low-level mass
response was not well sampled by the 00z RAOB network, so it`s a
bit difficult to gauge how deep the system is in an observational
sense. That said, recent GOES-16 Atmospheric Motion Vectors and
VWPs suggest a modest increase in 925-850 mb flow is ongoing, and
loops of KEAX reflectivity and velocity products clearly show the
circulation center somewhere in the vicinity of Grundy/Sullivan
counties in north-central MO.
This MCV appears to have its origins out of intense convection
which developed across Kansas last night and is now being
reinforced by additional significant latent heat release from
ongoing thunderstorms. Mid-level vorticity generation will
continue as a result, with this feature acting to some extent like
a tropical disturbance with a notable 500 mb "warm" core (recent
RAP analyses depict temperatures around -4 C within the
circulation, while environmental temperatures are around -8 C).
The big questions are 1) how "spun-up" this system becomes and 2)
where the surface reflection/vertically-stacked upper low tracks.
18z GFS mass fields are comparing pretty favorably to observations
(what little exist), and the 18z EPS additionally appears to back
up the GFS`s general idea as well. Unfortunately, the answers to
both 1 and 2 are functions of how vigorous convection gets
overnight tonight. Based on the available guidance suite and
current observations, suspect the 18z NAMNest was a bit too far
north, HRRR and RAP a bit too far south, with the GFS and
ECMWF/EPS offering up a more realistic middle ground, but
significant error bars on this remain.
Intense upper jet divergence in response to the mid-level
warming/thickness enhancement, along with what looks to be fairly
significant mid-level frontogenesis will support a narrow swath
of low-echo centroid, highly-efficient, heavy rainfall-producing
convective elements with warm cloud depths easily surpassing 13
kft. This will be exacerbated by the system`s very slow forward
motion with very little to help encourage it along. So while the
footprint of 6"+ amounts on guidance like the NAMNest is probably
too expansive, localized corridors of significant rainfall
amounts are possible about two tiers of counties north of the 850
mb circulation center. Unfortunately, it looks like this corridor
may attempt to set up somewhere in our CWA, with the greatest
potential for this somewhere near the Illinois and Kankakee
Rivers. Too much uncertainty in placing what will be a very narrow
swath of heaviest rainfall to justify a flood watch right now, but
we`ll probably need to consider one for parts of the area with the
overnight package. Finally, with MCVs in Illinois in August
usually comes a severe weather risk. Currently, though, it looks
like the main reservoir of surface-based instability may remain
just south of our region, but some tornado risk is evident into
central Illinois, wherever modest 0-3 km MLCAPE develops.
Updated products will be out shortly.
Carlaw
&&
.SHORT TERM...
Issued at 315 PM CDT Fri Aug 4 2023
Through Saturday night...
The threat for rain (potentially locally heavy) has increased
dramatically across our area for Saturday. Accordingly, the
forecast has been updated to include a notable increase in shower
and embedded thunderstorm chances, with likely chances (60-70%)
now mentioned for areas along and south of I-80 during the day.
The main feature we are watching for Saturdays weather is the
remnant MCV currently shifting into southwestern IA. This is
expected to fire off convection to our west this evening into
tonight, before the activity translates eastward into portions of
northern IL and northwestern IN on Saturday in advance of the MCV.
Very high moisture content (noted by tropical-like precipitable
water values ~2" and deep warm cloud depths in excess of 14,000
feet) accompanying this MCV suggest that very heavy rainfall
rates will be likely, and hence could result in some instances of
flash flooding into parts of our area on Saturday. This flooding
threat is also of increased concern due to the fact that the MCV
will move only very slowly eastward across IL during the day. This
may thus support several hours (5 to 8 hours) of nearly
continuous moderate to heavy rainfall in some parts of northern IL
and northern IN from mid to late morning through the afternoon or
early evening. At this time, uncertainty remains with where the
heaviest and most continuous rain (and the attendant flash flood
threat) will occur. However, conceptually speaking, the expected
track of the MCV would tend to favor areas around and south of the
I-80 corridor. No flash flood watch is planned at the present
time, but one could be needed along and south of I-80 if trends
continue to support this thinking.
Once this MCV finally peels off east of the area into Saturday
evening the rain and embedded storm threat will come to an end
from west to east. This should generally set up a period of
precipitation free weather Saturday night into Saturday morning
before our next period of active weather arrives. Reference the
long term discussion below for more on this.
KJB
&&
.LONG TERM...
Issued at 315 PM CDT Fri Aug 4 2023
Sunday through Friday
Key Messages:
* Severe weather still possible Sunday evening though confidence
in the location and coverage has decreased some
* Lingering showers and storms possible into Monday
* Another round of showers/storms possible late WED-THU
Discussion:
The upper-level trough and associated surface low currently over
the Northern Plains (MT, ND, SD) has slowed its eastward
progression in response to a disturbance/developing MCV to its
southeast over SW IA. This has resulted in some changes to the
expected the timing of showers and storms across the area into
Sunday, delaying the arrival of the surface low by several hours
with the highest chances for precipitation Sunday evening and
overnight.
After a marked change with the 12Z suite of model guidance over
the next 24-72 hours, both hi-res and global guidance are coming
into agreement on the timing and placement of the digging upper-
level trough and deepening surface low Sunday into Monday,
however, the exact path of the low will play a notable role in
Sunday`s severe weather setup. As such there are two scenarios
that could ultimately play out depending on that track. If the
center of the low track centers over the southern or central parts
of the area then the warm front may stay far enough south to keep
the more favorable severe weather conditions south of I-80. If
the low track leans further north across the WI/IL border, this
could give the area enough time in the warm sector for the
atmosphere to destabilize and increase the probability of greater
thunderstorm coverage. With MUCAPE values around 2000 J/Kg and
effective deep layer shear around 30-40kts wherever the warm
sector ends up, this would be supportive of at least isolated
severe thunderstorms. As of now, the better potential for severe
weather appears to be south of I-80, though this will continue to
be closely monitored and updated. Depending on how Saturday`s
heavy rainfall unfolds, areas that receive higher rainfall amounts
would be more susceptible to flash flooding with any
thunderstorms late Sunday. Stay up to date on the latest forecast!
Given the slower timing of the Sunday system shower and
thunderstorm chances have increased into Monday, potentially
through the afternoon. Again, depending on the placement of the
surface low some areas may see gusty winds, especially south of
I-80.
After a brief "cool down" Monday (highs in the upper 70s),
temperatures should warm back up near the seasonal average Tuesday
and Wednesday. The next rain and storm chances return late next
week as another trough is expected to dig into the region
Wednesday night into Thursday.
Carothers/Petr
&&
.AVIATION...
For the 00Z TAFs...
Forecast concerns for the terminals...
*Chances for widespread showers Saturday some of which could
produce locally heavy rainfall and reduced visibility
*Lowering ceilings with the showers with MVFR to IFR conditions
possible
A relatively quiet night is expected for the terminals as weak
ridging resides overhead. This will allow the current
northeasterly breezes to ease with speeds around 5 kts expected
through the overnight hours. However, cloud cover will be
increasing through the night as the developing complex of showers
and storms currently over northern Missouri moves into Illinois.
As the complex continues to push eastward on Saturday, widespread
showers and possible thunderstorms are expected to spread across
portions of central Illinois and northwestern Indiana some of
which could be produce locally heavy rainfall and reduced
visibility.
Latest guidance continues to be in disagreement on the exact track
this complex would take with many favoring a more southern track
which should keep the heaviest rainfall and storms south of I-80
and may allow areas near RFD to remain mostly dry. However, there
are some indications that a slightly more northward track is
still in the cards which could bring the axis of heaviest rainfall
near the southern terminals, particularly MDW and GYY. Given this
lingering uncertainty I have maintained the PROB30s in the TAFs
which seem to capture the best window of heaviest rainfall and the
resultant reduced visibility well.
Additionally, ceilings are also expected to lower with the
showers on Saturday with indications that MVFR conditions could
reach the Chicago terminals during the afternoon hours. There is a
chance that IFR conditions could occur within the axis of heaviest
rainfall, but given the aforementioned uncertainty on where this
axis will establish have opted to go with scattered MVFR mention in
the TAFs for now.
Yack
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...Beach Hazards Statement...ILZ006-ILZ103-ILZ104 until 7 AM
Saturday.
IN...Beach Hazards Statement...INZ001-INZ002 until 7 AM Saturday.
LM...None.
&&
$$
Visit us at weather.gov/chicago
Follow us on Facebook, Twitter, and YouTube at:
www.facebook.com/NWSChicago
www.twitter.com/NWSChicago
www.youtube.com/NWSChicago
Area Forecast Discussion
National Weather Service Memphis TN
955 PM CDT Fri Aug 4 2023
...New UPDATE...
.UPDATE...
Issued at 955 PM CDT Fri Aug 4 2023
Abundant moisture from today`s showers and clear skies may
result in patchy to dense fog development overnight for low lying
areas and near river basins. A similar setup to last night as another
MCS will track across the upper Ohio Valley and impact northeast
Arkansas and West Tennessee. This system is more robust and has a
quicker storm motion. There is less confidence in training storms
that would impact the northwest corner of Tennessee where they
have received roughly a foot of rain in a little over 24 hours.
Additional convection is expected to fire up during the afternoon
and evening hours tomorrow having more of an impact to north
Mississippi. Some of these storms may be strong with gusty winds
and heavy rainfall expected. Given these multiple rounds of
convection, at this time Heat Headlines may be necessary, but
could be similar to today and over perform as the convection moves
through. With that being said, high temperatures for tomorrow
were lowered generally to the upper 80s and lower 90s, but
dewpoints still seem to hang on in the mid 70s. We will continue
to monitor for any severe potential, dense fog, and heat
headlines. The extended forecast remains on track.
DNM
&&
.SYNOPSIS...
Issued at 253 PM CDT Fri Aug 4 2023
Hot and humid conditions will continue this weekend across the
Mid-South with additional chances of showers and thunderstorms. A
front will move through the region early next bringing slightly
cooler temperatures and not as humid conditions.
&&
.DISCUSSION...
(This evening through next Thursday)
Issued at 253 PM CDT Fri Aug 4 2023
The convection that brought the tremendous amount of rain to parts
of NW TN overnight has shifted south of the area. With the rain
and outflow moving across the Mid-South today, the heat headlines
had to be readjusted as temperatures are in the upper 70s to lower
80s at this time. The Excessive Heat Warning and much of the Heat
Advisory was cancelled. A heat advisory will remain in place from
Craighead County southward to Phillips County where temperatures
are most likely to recover. Looking ahead to Saturday, forecast
heat index values currently reflect heat advisory across a good
portion of the area and excessive heat warning criteria in our
southwest counties. However, the decision was made to hold off on
additional headlines to see if convective trends become more clear
for Saturday.
Heading into tonight, patchy fog was added to the forecast as
guidance started to latch on to this potential especially towards
the TN River westward towards Jackson and southward into N/NE MS.
Otherwise...another round of showers and thunderstorms will likely
occur tonight into Saturday morning. Storms should fire up across
NE AR and move off the southeast. Current thinking is the
heaviest activity will occur south of where the significant
rainfall and flooding occurred in NW, but will be monitoring these
trends closely. Additional convection may fire up during the
afternoon and evening hours from eastern AR and sweep eastward
into NE MS. Main threat with this activity will be locally heavy
rainfall but given the amount of instability present, there may be
a few strong storms with gusty winds.
By Sunday, upper level trough will move across the Upper Midwest
and Great Lakes Region with a frontal boundary nearby. This will
result in better chances of organized convection during the
afternoon and evening hours on Sunday. Some of these storms
may become severe along with the threat of heavy rainfall. The
potential for flooding will exist if training of storms occurs and
saturated soils across the region.
The boundary actually moves through the Mid-South early next week
bringing slightly cooler temperatures and more tolerable humidity
levels to the Mid-South. The northerly winds will be short-lived
as southerly winds return on Wednesday. However, unsettled weather
will persist with isolated to scattered convection possible each
day.
&&
.AVIATION...
(00Z TAFS)
Issued at 656 PM CDT Fri Aug 4 2023
Primary aviation weather concern remains timing and coverage of
TSRA. Similar to last night, northwest flow aloft will prevail,
though the storm track appears to line up slightly further west.
This would place JBR, MEM and MKL in the path of storms after 06Z.
2345Z radar mosaic and GOES IR imagery showed mature TSRA
clusters east of MCI, moving slowly ESE. Both the HRRR and NSSL-
WRF model develop additional TSRA over southern MO late this
evening, with a more southeasterly movement. 00Z TAFs followed
the aforementioned CAM timing for TSRA at JBR, MEM and MKL, but
allowed for slightly earlier arrival times.
Confidence after 12Z begins to wane. Several CAMs depict additional
morning convection, but this activity will likely be accompanied
by less instability and lightning potential, given expected airmass
modification. Next round is depicted by the HRRR and NSSL-WRF
arriving from central AR after 00Z, after the airmass has time to
recover.
PWB
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...None.
MO...None.
MS...None.
TN...None.
&&
$$
PUBLIC FORECAST...DNM
AVIATION...PWB
Area Forecast Discussion
National Weather Service Pendleton OR
856 PM PDT Fri Aug 4 2023
.EVENING UPDATE...Satellite and radar imagery this evening show
thunderstorm activity coming to a close around the forecast area,
though thunderstorms continue to push across far southern OR.
Meanwhile, a band of persistent area of light rain that started
across the eastern mountains continues to meander west northwest
across the forecast area. This band of precipitation is associated
with the arrival of a weak low aloft. An area of vorticity and
moisture advection oriented along the WA/OR border into western MT
associated with the low will continue to bring light rain chances
across far northern/northeastern OR and central/southeast WA
through the rest of tonight into to early tomorrow morning.
Tomorrow, the upper low will continue to sit over the region,
resulting in another round of rain showers across the forecast
area, with best chances of isolated to widely scattered
thunderstorms over the OR Cascades, central OR, and the eastern
mountains in the afternoon. Thanks to the low aloft, temperatures
are expected to be much cooler tomorrow afternoon, with widespread
mid 70s to lower 80s, with 60s to lower 70s in the mountains.
Lawhorn/82
&&
.PREV DISCUSSION... /issued 416 PM PDT Fri Aug 4 2023/
.SHORT TERM...Tonight through Sunday night...Thick cloud cover
and rain showers have been over most of the forecast area, and is
persisting into this afternoon. There is rain falling at many
locations across central and east central OR and portions of the
NE mountains. There has not been any lightning strikes with these
showers. RH`s have been high in these areas as well, with most
values above 50 percent, and some as high as 80+ percent. Have
therefore decided to cancel the Red Flag Warning for fire zones
OR644 and OR645 (the southern Blue Mountains and Wallowa County
areas). Confidence in thunderstorms with abundant lightning to
start new fires has fallen to low to moderate (30-50%). Will leave
the remaining Red Flag Warnings in place as the satellite is
starting to show some clearing beginning to take place in central
and southeast OR, which will likely increase northward into fire
zones OR611, OR640 and OR642. These Red Flag Warnings will remain
in effect until 11 PM for thunderstorms with abundant lightning
(confidence for abundant lightning remains at least 80%).
Conditions are evolving such that an upper low has formed to the
east of the forecast area, and is forecast by some of the high
resolution ensemble forecast models to develop a little further
westward, with a closed circulation over northeast OR by late
tonight into Saturday morning (50-70% chance). This will cause
wrap around moisture to increase in the northeast mountains, with
a period of general rainfall, with little or any thunderstorms
with abundant lightning (though cannot rule out thunderstorms
completely). This area is forecast to be from the eastern Lower
Columbia Basin eastward across the northern Blue Mountains into
Wallowa County, and the Northern Blue Mountains across southeast
WA as well. The NAM Nest and HRRR models are forecasting this
precipitation to persist through Saturday morning into the
afternoon hours before it lifts out to the N-NE in the evening
(80-90% confidence). There may be some thunderstorms in the
afternoon and early evening Saturday in these areas, but the
thunderstorms may be mostly wet, with cooler and more humid
conditions in place, and LALs of only 2. That being said, well
leave a slight chance of thunder in the forecast for these areas
as they cannot be ruled out completely, however confidence is only
low to moderate (30-50%) that they will contain abundant
lightning, or ignite new fires.
On Sunday, the short term models are now showing an upper closed
low lingering over northeast OR and southeast WA. This will keep
showers and isolated thunderstorms going, mainly from the WA
Cascades east and southeastward to the northeast mountains of OR
and southeast WA. Will take out the mention of thunder late
Saturday night/early Sunday morning, and add it back in for
Sunday afternoon. Conditions will then begin to dry out Sunday
night going into the extended forecast...at least early in the
extended period. Confidence in this forecast scenario is moderate
to high (60-80%).
High temperatures this afternoon will likely be cooler than
previously forecast, due to the cloud cover and precipitation.
Then lows tonight will be in the 60s to near 70 lower elevations,
and mostly upper 40s to mid 50s mountains. Highs on Saturday will
then be considerably cooler, with highs only in the lower to mid
80s lower elevations, and mid 60s to mid 70s mountains.
Temperatures will then rebound a few degrees on Sunday, with highs
back into the mid 80s to near 90 lower elevations, and mostly 70s
to near 80 mountains. Temperatures will continue to warm back up
going into the extended forecast period. It will continue to be
locally breezy in the normally wind prone areas, otherwise winds
be mostly light winds through the short term period. 88
.LONG TERM...Monday through Friday...Models are generally in good
agreement through the period. However, there are some
discrepancies in the strength of an elongated upper level trough
off the coast and its influence on the Pacific Northwest and the
strength of a developing ridge next weekend. The EOFs show the
main difference is amplitude (strength) of both the upper level
trough impacting the area Monday into Wednesday and an amplifying
ridge Friday. With respect to the ensembles, GFS is a little
stronger with the trough and amplifies the ridge a little slower
while the ECMWF is a little weaker with the trough and amplifies
the ridge faster. Overall, these subtle differences make little
difference in the overall weather pattern. In summary, Monday
through Wednesday will be more active with showers and
thunderstorms, mainly over Washington, then a transition to drier
and warmer by Friday.
The deterministic models show even more differences in their
solutions. The ECMWF pushes the first upper trough out of the area
by afternoon while the GFS moves it through Monday night. By Tuesday
afternoon, the ECMWF shows a very weak disturbance moving through
Washington. Meanwhile, the GFS shows a stronger shortwave moving
through Wednesday morning into the afternoon. Confidence is high (60-
70%) in the overall pattern, but low (15-20%) in the timing and
strength of these events. Either way, the bulk of showers will be
over Washington. By Thursday, upper level westerly flow will begin
to buckle as a ridge begins to build off the coast. There is
moderate (40-50%) confidence this will mark the beginning of a dry
and warmer period through middle of following week as depicted by
the ensemble means and WPC cluster analysis. Daytime highs will be
near to slightly below normal through the period with moderate (35-
40%) confidence in a warming trend starting Friday.
Winds will be locally breezy Tuesday afternoon through the Columbia
River Gorge and throughout the Columbia Basin Wednesday. Earle/81
.AVIATION...00Z TAFs...VFR conditions will prevail through the
period. Thunderstorms developing across central OR will come at
least within vicinity of sites RDM/BDN this afternoon, while there
is a possibility of thunderstorms moving over site BDN, reducing
vsby to MVFR levels and creating gusty and erratic winds.
Otherwise, all other sites can expect bkn CIGS AOA 10kft-15kft AGL
through the rest of the period. Winds will generally be light,
less than 12kts, through the period, with occasional afternoon
gusts up to 20kts possible. Lawhorn/82
&&
.PRELIMINARY POINT TEMPS/POPS...
PDT 63 80 60 84 / 20 30 20 30
ALW 68 82 62 86 / 20 40 20 40
PSC 71 83 66 88 / 20 40 20 30
YKM 67 82 62 87 / 20 30 20 40
HRI 68 85 65 89 / 20 20 20 30
ELN 64 79 62 87 / 20 30 20 30
RDM 51 82 54 86 / 20 20 10 0
LGD 60 80 56 82 / 30 40 20 40
GCD 53 83 54 85 / 20 20 10 20
DLS 66 88 67 92 / 20 20 10 10
&&
.PDT WATCHES/WARNINGS/ADVISORIES...
OR...None.
WA...None.
&&
$$
EVENING UPDATE...82
SHORT TERM...88
LONG TERM....81
AVIATION...82
Area Forecast Discussion
National Weather Service Pueblo CO
310 PM MDT Fri Aug 4 2023
.SHORT TERM...(This evening through Saturday)
Issued at 308 PM MDT Fri Aug 4 2023
Key Messages:
1) Showers and thunderstorms are possible this afternoon and this
evening, mainly across highway 50 corridor and the eastern plains.
Some could be strong to severe.
2) A cold front pushes through our plains tomorrow, bringing more
chances for strong to severe thunderstorm activity to most of the
area, especially east of the I-25 corridor.
3) Critical Fire Weather conditions are expected for the San Luis
Valley tomorrow, where a Red Flag Warning is valid from 11am through
8pm.
Currently..
Water vapor imagery depicts a low moving across the northern Rockies
towards the northern plains this afternoon, with very dry air making
its way into western portions of the forecast area, especially in
the mid and upper-levels. At the surface, some moisture has backed
into our plains thanks to easterly and southeasterly winds. The
dewpoint at La Junta is still holding steady at 55, while Lamar is
still at 61 as of 3pm. Cu has popped across most of the forecast
area, though no showers or storms to report quite yet as dry air
remains entrenched over the higher terrain. One lone sub-severe cell
has developed just northeast of El Paso County.
Rest of Tonight..
High res models continue to hint at the possibility of shortwave
energy sparking showers and thunderstorms over the Wet Mountains
later this afternoon and into the evening hours. Both the NAMnest
and HRRR show thunderstorm activity popping up around the Custer
County and Pueblo County line after 6pm this evening, and pushing
eastward throughout the evening hours. Current thinking is that this
activity will be sub-severe, though with decent shear in place and
over performing dewpoints, we may need to keep a close eye on
convection across the highway 50 corridor this evening. Main threats
at this point look to be damaging winds given inverted v forecast
sounding profiles and over 1400 J/kg of DCAPE.
Another area to keep a close eye on will be our far eastern plains,
mainly through Kiowa, Bent and Prowers counties. Though major
synoptic features will remain to our northeast tonight, a weak
nocturnal low level jet looks to sustain convection into the
overnight hours. Decent shear and 1500 to 2000 J/kg of CAPE are
forecast for this area later this afternoon, suggesting that storms
could become strong to severe as they move eastward and encounter
this more favorable environment.
Saturday..
Dry, westerly flow increases over the high country tomorrow, as the
low to our northeast pushes a cold frontal boundary through our
plains tomorrow afternoon. This set up will mean critical fire
weather conditions for the San Luis Valley, along with more chances
for strong to severe storms on our plains. Both the HRRR and the
NAMnest push the cold front into El Paso County anywhere between 2pm
and 4pm, sparking showers and thunderstorms across the Palmer Divide
and spreading them south and eastwards throughout the rest of the
afternoon and evening. With the upper jet over the region tomorrow
afternoon and at least 20 or so kt of shear, storms should be able
to stay organized as they push south and eastward. Best chances for
severe look to remain across the Palmer and areas along and east of
the I-25 corridor, where more favorable moisture and instability is
forecast to exist by tomorrow afternoon. All modes of severe will be
possible, with highest risks for damaging winds and hail up to 2
inches being possible again mainly across the Palmer and the plains
east of I-25.
.LONG TERM...(Saturday night through Friday)
Issued at 308 PM MDT Fri Aug 4 2023
Key Messages
1) Increasing fire weather concerns for the mountains and high
valleys with fire weather concerns possibly spreading into
the southern I25 corridor next week.
.Sunday...Cooler low level airmass is over the eastern plains with
highs on Sunday in the upper 70s to mid 80s on the plains. Models
soundings show a relatively stable atmosphere on the eastern
plains. Ensembles have very low probabilities of CAPE greater than
1000 J/kg with highest probabilities over the eastern mountains.
NBM is rather generous with high scattered PoPS on the plains
during the afternoon and evening. Disturbance passing to the north
may result in some shallower convection developing. There will be
plenty of shear with forecast 400mb winds around 40 knots, so if
deeper convection develops will have to watch for stronger
convection.
Further west, dry and mild mid levels will result in generally
warm and dry weather with some high based weak convection
possible. Fire weather concerns continue with low humidities and
modestly gusty winds. Fire weather zones 220, 223, and 224 have
widespread red flag conditions, but currently fuels are only
critical in zone 224 (San Luis Valley). Will issue a fire weather
watch for fire weather zone 224.
.Monday through Friday...The "non"-soon versus the monsoon
continues over the mountains and high valleys with ensemble means
showing PWAT values of 50 to 70% of normal through at least
midweek. Daytime humidities will be low most days for the threat
of critical fire weather conditions. Limiting factor will be
winds as flow aloft weakens towards midweek. There are hints of
increased mid level moisture towards the end of the week. GEFS
mean has PWAT approaching the normal range by Friday, but the GEFS
tends to increase monsoon moisture to quickly. ENS has PWAT
"increasing" to only around 80% by the end of the week.
On the plains, a warming and drying trend develops with highs well
into the 90s on the plains by Tuesday. Best chances for
precipitation will be on Monday, closer to the Kansas border
where deeper low level moisture will remain. Otherwise, isolated
high based storms over the eastern mountains may move eastward
into the I 25 corridor. GEFS and ENS have zero or very low
probabilities of CAPE above 1000 J/kg throughout the week except
closer to the Kansas border on Monday. By the end of the week, a
modest increase in moisture may bring a slightly better chance
for storms over the eastern mountains. Critical fire weather
conditions may spread into the southeast mountain and into the
southern I25 corridor with lower minimum humidities. Fire weather
zone 225 (southeast mountains) has critical fuels so there is the
potential for fire weather highlights for this area next week.
--PGW--
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 308 PM MDT Fri Aug 4 2023
For KCOS and KPUB..VFR ceilings and visibilities are expected for
the next 24 hours. Showers and thunderstorms are not expected on
station today, but there is a low end chance that storms could move
within the vicinity later this evening, mainly between 00 and 03Z,
and especially for KPUB. Have left mention of vcts out of the TAF
for now as confidence is low at this point. Gusty and erratic
outflow winds will be possible on station near any storms that
manage to develop later today. Better chances for showers and
thunderstorms move in tomorrow. Winds will follow mainly diurnal
patterns outside of thunderstorm activity.
Key Messages
1) Increasing fire weather concerns for the mountains and high
valleys with fire weather concerns possibly spreading into
the southern I25 corridor next week.
.Sunday...Cooler low level airmass is over the eastern plains with
highs on Sunday in the upper 70s to mid 80s on the plains. Models
soundings show a relatively stable atmosphere on the eastern
plains. Ensembles have very low probabilities of CAPE greater than
1000 J/kg with highest probabilities over the eastern mountains.
NBM is rather generous with high scattered PoPS on the plains
during the afternoon and evening. Disturbance passing to the north
may result in some shallower convection developing. There will be
plenty of shear with forecast 400mb winds around 40 knots, so if
deeper convection develops will have to watch for stronger
convection.
Further west, dry and mild mid levels will result in generally
warm and dry weather with some high based weak convection
possible. Fire weather concerns continue with low humidities and
modestly gusty winds. Fire weather zones 220, 223, and 224 have
widespread red flag conditions, but currently fuels are only
critical in zone 224 (San Luis Valley). Will issue a fire weather
watch for fire weather zone 224.
.Monday through Friday...The "non"-soon versus the monsoon
continues over the mountains and high valleys with ensemble means
showing PWAT values of 50 to 70% of normal through at least
midweek. Daytime humidities will be low most days for the threat
of critical fire weather conditions. Limiting factor will be
winds as flow aloft weakens towards midweek. There are hints of
increased mid level moisture towards the end of the week. GEFS
mean has PWAT approaching the normal range by Friday, but the GEFS
tends to increase monsoon moisture to quickly. ENS has PWAT
"increasing" to only around 80% by the end of the week.
On the plains, a warming and drying trend develops with highs well
into the 90s on the plains by Tuesday. Best chances for
precipitation will be on Monday, closer to the Kansas border
where deeper low level moisture will remain. Otherwise, isolated
high based storms over the eastern mountains may move eastward
into the I 25 corridor. GEFS and ENS have zero or very low
probabilities of CAPE above 1000 J/kg throughout the week except
closer to the Kansas border on Monday. By the end of the week, a
modest increase in moisture may bring a slightly better chance
for storms over the eastern mountains. Critical fire weather
conditions may spread into the southeast mountain and into the
southern I25 corridor with lower minimum humidities. Fire weather
zone 225 (southeast mountains) has critical fuels so there is the
potential for fire weather highlights for this area next week.
--PGW--
For KALS..VFR ceilings and visibilities are expected for the next 24
hours. Westerly winds gusting up to 25kt are expected for the rest
of this afternoon, and breezy westerly winds will return for
tomorrow as well. Cloud cover should remain mostly mid-level or
higher, and precipitation is not expected in the vicinity through
the period.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning from 11 AM to 8 PM MDT Saturday for COZ224.
Fire Weather Watch from Sunday morning through Sunday evening
for COZ224.
&&
$$
SHORT TERM...EHR
LONG TERM...PGW
AVIATION...EHR
Area Forecast Discussion
National Weather Service Reno NV
143 PM PDT Fri Aug 4 2023
.SYNOPSIS...
Hazy skies were caused by a combination of dust lofted by
thunderstorms yesterday evening in addition to some smoke aloft.
Otherwise, chances for afternoon and evening thunderstorms
continue through Saturday, before drier conditions return Sunday
into the start of next week. Temps will remain near normal with
typical afternoon winds, except Monday, which will be warmer, and
Tuesday will be breezier.
&&
.DISCUSSION...
* Skies are hazy throughout the Truckee Meadows today due to a
combination of dust and smoke aloft. Per conversations with
Washoe County Air Quality Management Division, and their PM10 vs
PM2.5 measurements, it`s roughly 70% dust, or larger particulate
matter, and 30% possible smoke, or smaller particulate matter.
The potential smoke sources are the Pika Wildfire near Yosemite,
a Rx Burn in the Stanislaus NF, in addition to wildfires burning
in Oregon. All of this is aloft, per HRRR smoke modeling and
contributing much less than the dust. Most air quality sensors
in the region are still in the good category as of the time of
writing, with a few edging into moderate. For the latest,
please visit fire.airnow.gov. Increasing westerly breezes this
afternoon should help to improve mixing and clear the air.
* Otherwise, we`re still on track for thunderstorms to develop
this afternoon and evening. Based on HREF guidance, the best
chances (20-40%) remain for areas north of I-80 today, but
there is still a 10-20% chance for a few storms to fire off
along the western Nevada Sierra Front as far south as Hwy-50.
Anticipate typical thunderstorm impacts including frequent
lightning, localized heavy rainfall with 0.25-0.75" under
thunderstorm cores, and gusty/erratic outflow winds which could
once again kick up dust. There is a small risk for flash
flooding if storms train or stall over steep terrain or burn
scars. Chances for storms shift north, closer to the Oregon
border, on Saturday, before a drier air mass returns on Sunday.
* Overall temperatures will remain seasonable, except for a brief
spike ~5 degrees above normal on Monday with minor heat health
impacts possible. A trough approaching the coast Tuesday will
return temps to near normal and also bring enhanced breezes with
gusts of 30-35 mph, per blended guidance. The combination of
dry and breezy conditions will bring enhanced fire weather
concerns Tuesday afternoon. See fire section below for
additional details.
* Longer range ensemble guidance is showing odds leaning toward
above normal temperatures returning, with increasing PWATs
bringing some thunderstorm chances once again the end of next
week. -Dawn
&&
.AVIATION...
* The haze throughout the region may be impacting slantwise
visibility, but is anticipated to improve throughout the
afternoon as the afternoon breezes kick in. Anticipate typical
westerly breezes from 21z-03z at terminal sites with gusts 15-
20 kts.
* We`re still anticipating thunderstorms to develop this
afternoon, with a 20-40% chance north of I-80, and a 10-20%
chance as far south as US-50. Localized heavy rainfall under
storm cores may obstruct visibility and storms may also produce
gusty and erratic outflows, which could once again kick up dust.
Chances for storms shift north, closer to the Oregon border, on
Saturday, before a drier air mass returns on Sunday. -Dawn
&&
.FIRE WEATHER...
* Thunderstorms have been producing wetting rains, but storm cores
have been small and dry strikes are being observed the past few
days outside of thunderstorm cores. With the storms being a
wet/dry hybrid, and fuels still not overly receptive, outside of
grasses which are cured, there are no fire watches or warning
in effect.
* Otherwise, we`re looking at dry and breezy conditions on Tuesday,
with localized critical conditions possible. Winds are expected to
gust in the 30-35 mph range, per blended guidance, but have a 25%
chance to reach 40 mph in wind prone locations. Minimum RH values
could drop as low as 10-15% Tuesday afternoon. -Dawn
&&
.REV Watches/Warnings/Advisories...
NV...None.
CA...None.
&&
$$
Area Forecast Discussion
National Weather Service Tucson AZ
121 PM MST Fri Aug 4 2023
.SYNOPSIS...Hot and dry weather will prevail through this weekend.
Increased moisture will bring chances for thunderstorms early
next week.
&&
.DISCUSSION...An elongated area of high pressure in the upper
atmosphere stretched AZ to the Gulf of Mexico with a stronger
center from SE AZ to SW NM. Subsidence under the high has dried
out the atmosphere well below normal levels for early August.
Thus, heat will be the main story this weekend with the current
Excessive Heat Warning in all SE AZ counties on track. The
probability of reaching 110+ degrees in Tucson Saturday has
decreased slightly to 49%. Sunday, the probability is 25%.
We are seeing a few high based cumulus clouds this afternoon.
Going forecast has a slight chance of a shower or thunderstorm
this afternoon over the Huachucas and Chiricahuas. While latest
HRRR not latching on to this, wouldn`t be surprised if a storm
popped over the Chiricahuas in better moisture and just enough
instability. Saturday looks dry area wide as high continues to
exert its influence.
On Sunday, will carry small chances for storms mainly south of
Tucson. However, ensembles show the high holding steady with a
slight erosion of its western edge not taking place until Monday as
disturbances in northern Mexico trigger thunderstorms and try to
push NW out of Sonora with an associated a surge of moisture up
the Gulf of California and a general increase in PWAT values. If
this occurs, moisture could limit extreme heating. Thus will not
extend the EHW past Sunday at this time.
Additionally, that moisture would return chances for thunderstorms
to our area as early as Monday or Tuesday. Latest NBM PoPs are
just a bit higher Monday vs Tuesday.
After that, the latest ensembles shift the high further south and
east, putting AZ in southwest flow. That could bring in enough
moisture to keep thunderstorm chances going through the week.
Speaking of moisture to our southwest late next week...an upper
level disturbance well south of Puerto Vallarta Mexico is forecast
to track WNW through early next week. This path would be farther
north than this week`s hurricane Dora took, but still well south
and west of Baja. While a direct tropical influence is not
expected here, perhaps this could be an indirect source of
moisture for us late next week. By the way, if that disturbance
intensifies, it would become Eugene.
&&
.AVIATION...valid through 06/00Z.
SKC through the period except FEW-SCT clouds AOA 15-20k ft MSL
through sunset. Perhaps an ISOLD -SHRA/-TSRA over mts near KDUG
until 05/01z. SFC wind WLY 10-15kts with gusts up to 20kts til
05/03z and again Saturday afternoon. Otherwise SFC winds generally
remain under 10 kts and follow diurnal trends. Aviation discussion
not updated for TAF amendments.
&&
.FIRE WEATHER...Hot and dry conditions through this weekend with
afternoon gustiness, which will dry fuels somewhat. Minimum
humidities Saturday will be 8 to 16 percent in the lower
elevations and 12 to 20 percent in the mountains. Increased
moisture is expected early next week, which will bring back the
chance for daily rounds of mainly afternoon and evening
thunderstorms.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...
Excessive Heat Warning until 8 PM MST Sunday for AZZ501>509.
&&
$$
Drozd
Visit us on Facebook...Twitter...YouTube...and at weather.gov/Tucson