Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 08/03/24
Area Forecast Discussion
National Weather Service Grand Forks ND
631 PM CDT Fri Aug 2 2024
.KEY MESSAGES...
There is a level 2 out of 5 severe thunderstorm risk Saturday
afternoon and early evening across west central Minnesota, with
a level 1 risk surrounding that area from southeastern North
Dakota into the Bemidji area.
&&
.UPDATE...
Issued at 632 PM CDT Fri Aug 2 2024
Mostly clear skies prevail this evening across much of the
Northern Plains. Temperatures range from the low 80s near Lake
of the Woods to near 90 at various points in the Red River
Valley. The forecast remains on track this evening.
&&
.DISCUSSION...
Issued at 309 PM CDT Fri Aug 2 2024
Continued very quiet tonight as the upper ridge begins to shift
off and we get high pressure moving east. A shortwave trough
will dig down out of Canada and into the upper midwest tomorrow,
helping to push a cold front into our counties. There is still a
lot of uncertainty in the exact timing of the frontal passage.
The HREF has a 100 degree spread across a large swath of the CWA
from the morning into the early afternoon, moving north to
south. If the faster scenario verifies our severe chances will
be pretty low as the boundary will be past us before peak
heating. On the other hand, if the front comes through slowly,
we will get plenty of destabilization with over 3000 J/kg of
CAPE possible. Deep layer bulk shear is around 40 kts, and
supercells will be possible for a few hours if the slower
scenario comes true. While earlier runs of the CAMs were leaning
towards the faster frontal passage, a few of the more recent
runs, including the HRRR break out some very healthy convection
in our west central MN counties. HREF has updraft helicity
probabilities getting up to 50 to 60 percent in our far
southeast by late evening, and SPC has raised the outlook to
slight. Large hail will be the primary threat as storms develop
over our area and then move southeast with the cold front.
The severe threat will be pretty short lived as the cold front
pushes south of our counties before 05Z on Sunday. Another weak
ridge riding shortwave will be coming into the region and
interacting with the stalled boundary across the Dakotas on
Sunday and again Monday, bringing some precipitation chances.
Some signal in the R and M climate of wetter than usual, but at
this point not strong enough to start messaging heavy rainfall
potential.
Northwesterly flow aloft wets up for the rest of the work week,
with some additional weak shortwaves bringing precipitation
chances and a cooler than average airmass with highs in the 70s
and lows in the 50s, maybe even a few 40s possible.
&&
.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 632 PM CDT Fri Aug 2 2024
VFR conditions prevail through the period at all TAF sites. Look
for winds to go light and variable overnight before increasing
out of the north to northeast Saturday as a cold front passes
through the area. There is a low chance for an isolated shower
or thunderstorm very early Saturday morning, mainly at KBJI and
KTVF.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...None.
MN...None.
&&
$$
UPDATE...Lynch
DISCUSSION...JR
AVIATION...Lynch
Area Forecast Discussion
National Weather Service Goodland KS
940 PM MDT Fri Aug 2 2024
.KEY MESSAGES...
- Storms late this afternoon through the overnight hours may
pose some severe threat with damaging winds around 65 mph and
to a lesser extent hail around half dollar size. A Heat Burst;
can`t be ruled out tonight.
- Triple digit temperatures return to start the week.
- Mid-week system is expected to bring some storms followed by
cooler temperatures.
&&
.SHORT TERM /THROUGH SATURDAY NIGHT/...
Issued at 152 PM MDT Fri Aug 2 2024
NW flow continues to persist across the area as skies currently
remain clear. This afternoon am currently watching a 5-10% chance
for isolated development mainly along and north of Highway 36 due to
some 850-700mb FGEN along with some weak moisture return in the 700-
500mb range. If a storm were to form then large hail around half
dollar size with MUCAPE around 1800 j/kg and 0-6 shear of 30-35
knots. Some damaging wind threat would be possible as well with a
Microburst composite of 3 and DCAPE in the 1500-2000 j/kg range. A
relative better potential for showers and storms comes this
evening and overnight. Storms off of the Cheyenne Ridge and
Palmer Divide look to move to the ESE across the CWA. Some
severe potential in the form of damaging winds around 60 mph
looks to be primary threat especially if its cold pool driven,
which is completely plausible given that a SSE oriented LLJ
around 25-30 knots will be feeding into the the potential
cluster . There may be some hail threat as well with any mature
updraft as wind shear remains around 30 knots along with
increase low and mid level lapse rates into the 8-8.5C range.
The main severe threat looks to last through 10Z when an MCV may
actually form out of the convection allowing showers and storms
to persist through mid morning Saturday. We may need to keep an
eye on heat burst potential tonight as well with the convection
as the HRRR is suggesting some localized dew point drops within
the convection, primarily across Yuma county. RAP and NAM also
do show the 700-500mb moisture remaining fairly high through
this time period as well so have added in 20-25% pops to account
for this.
Depending on how long the residual convection does last for will
have an influence on temperatures for tomorrow due to lingering
cloud cover. PWATS do look to be high in the 1.2-1.3 range
Saturday morning along with slow storm motions. If storms do
want to linger, then heavy rainfall would be of concern,
especially across eastern Gove county where heavy rainfall fell
on Wednesday and soil moisture is currently around 25-30%. As a
result of this scenario looking more likely have lowered high
temperatures a few degrees for Saturday into the lower 90s.
Further support for this as well with 1000-500mb thickness
showing dam in the 575-580 range which supports "cooler" air.
The NAM is the most aggressive with the lower temperatures with
rain cooled air making eastern portions of the area struggle to
get into the 80s. So as mentioned current highs are in the low
90s for the majority of the area but if the stratus and rain
cooler air scenario starts presenting itself more then these
temperatures will need to be lowered even more. However any
precipitation chances should end north to south starting during
the mid morning hours as drier air in the e700-500mb level
pushes in.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
Issued at 152 PM MDT Fri Aug 2 2024
Ridging remains in place to start the extended period along with
warm above normal temperatures in place. With 850mb temperatures
around 29-33C across the area am thinking that highs in the mid to
upper 90s seems reasonable with perhaps some spotty low end triple
digits in place. precipitation chances look to be fairly low
Sunday with no obvious signs of forcing seen at this time.
However do think that chances for showers and storms should
increase as we head into the new work week. A stronger wave off
of the Front Range on Monday will be the focus as rainfall
looks to move west to east towards the CWA. Additional potential
for rainfall will continue through the middle part of the week
as a fairly strong cold front for mid August standards looks to
approach the area. There does remain discrepancies on when the
front will move through but a return to below normal
temperatures in the 80s is looking to be in the realm of
possibility. Will also need to keep an eye on heavy rain
potential as some guidance does indicate PWATS increasing in
excess of 1.5 inches.
As for Monday will need to watch for near critical to even critical
fire weather conditions. The above mentioned cold front looks to
situated across the northern Plains as a result lightning the
pressure gradient across the northwestern counties where some
wind gusts around 25 mph may occur. Highs look to be in the
upper 90s to mid 100s across the area as well. Will need to
monitor this potential set up as well.
&&
.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 940 PM MDT Fri Aug 2 2024
KGLD...VFR conditions are expected through the period.
VRB15g25kt winds are anticipated through 08z as
showers/thunderstorms and outflow winds impact the terminals
weather. A few lingering showers are possible around/over the
terminal from 08z-13z. From 08z-13z, light and variable winds
are expected then becoming southerly up to 12kts after 14z.
KMCK...VFR conditions are expected through the period. Showers,
possible thunderstorms will be around/over the terminal from
taf issuance through 14z. Winds are expected to be light and
variable but erratic gusts up to 30kts are possible around any
showers/thunderstorms. After 15z, south to southwest winds up to
11kts are currently forecast.
&&
.HYDROLOGY...
Issued at 152 PM MDT Fri Aug 2 2024
More of a conditional threat but an overnight through mid
morning MCV looks to create additional rainfall across eastern
portions of the area. PWATS around 1.3 inches, slow storm
movement and the potential for repeated rounds of rainfall may
lead to a conditional risk of some flooding across eastern Gove
county where soil moisture is higher near 30% as 1-2.5 inches
of rainfall fell on Wednesday.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...None.
CO...None.
NE...None.
&&
$$
SHORT TERM...Trigg
LONG TERM...Trigg
AVIATION...99
HYDROLOGY...
Area Forecast Discussion
National Weather Service Green Bay WI
1052 PM CDT Fri Aug 2 2024
Updated aviation portion for 06Z TAF issuance
.KEY MESSAGES...
- Above normal temperatures continue through Saturday. The
passage of a cold front Saturday night into Sunday will result
in temperatures returning close to normal early next week.
- Storm chances return at times from Saturday night through
Monday night, including the potential for MCS activity later
Sunday night through Monday night.
&&
.DISCUSSION...
Issued at 249 PM CDT Fri Aug 2 2024
Short Term...Tonight and Saturday
The latest RAP analysis and satellite/radar imagery show an upper
level low pressure system moving east across Indiana and Ohio
while high pressure stretches from north to south across the
Great Plains. A much drier airmass has moved into the region
compared to 24 hours ago as satellite analyzed precipitable water
values range from about 0.90 to 1.25 inches early this afternoon.
Even drier air exists behind a weak cold front, which is draped
across western Lake Superior and far northwest Wisconsin.
Scattered convective clouds have formed along the front where the
atmosphere is uncapped. Wouldn`t be surprised to see an isolated
shower or storm develop, but will keep showers out of the
forecast as chances look too low. The airmass is dry behind the
front (dewpoints in the 40s and 50s), weather impacts will be
minimal through Saturday afternoon.
The upstream cold front will move across northern Wisconsin dry
tonight before settling into the southern Great Lakes on Saturday.
Weak high pressure will slide into the area behind the front. The
only noticeable chance with the airmass behind the front will be
a drop in humidity levels as dewpoints fall into the middle 50s to
lower 60s.
The arrival of drier air behind the front will reduce the risk of
ground fog late tonight. Perhaps patchy fog will be possible at
the cold spots of north-central Wisconsin. Temperatures will
remain very warm on Saturday with highs in the middle to upper
80s. But because of the lower humidity, heat indices will be at or
slightly below the actual air temperature.
The airmass will remain capped through Saturday so no
precipitation is forecast.
Long Term...Saturday Night Through Friday
The upper wind pattern is forecast to become west northwest next
week as the westerlies strengthen and move south into the northern
Plains and Great Lakes.
A cold front will move south across the region late Saturday
night and Sunday and produce scattered showers and thunderstorms.
It is forecast to stall over southern Wisconsin Sunday night as it
becomes parallel to the upper flow. Waves of low pressure moving
along the front Monday and Tuesday could bring significant rainfall
to the southern half of the forecast area with strong over running
of the front.
Warmer than usual temperatures will continue Sunday, but cooler
weather is on the way for the remainder of next week. Monday and
Tuesday could be quite cool with cloud cover and rain, but sunny
skies, low humidity and pleasant temperatures are likely Wednesday
through Saturday.
&&
.AVIATION...for 06Z TAF Issuance
Issued at 1052 PM CDT Fri Aug 2 2024
Good flying weather continues through Saturday afternoon as high
pressure moves southeast across the region. Despite light winds
and mostly clear skies through the TAF period, drier air moving in
from the northwest will keep ground fog potential low tonight. Very
few cu will be around Saturday, but will begin to see mid and high
clouds increase from the northwest late in the day with scattered
to broken clouds on Saturday evening.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
DISCUSSION.....MPC/RDM
AVIATION.......JLA
Area Forecast Discussion
National Weather Service Grand Rapids MI
1005 PM EDT Fri Aug 2 2024
.KEY MESSAGES...
- Thunderstorms exiting southeast tonight, dry Saturday
- Heavy rain potential Sunday night into Monday night, then cooler
&&
.UPDATE...
Issued at 1002 PM EDT Fri Aug 2 2024
The small craft advisory was canceled early given the trends in
coastal observations. We expanded the mention of fog for tonight.
With the recent rain, low level moisture will be elevated in some
areas. This should increase the potential for fog tonight. Several
sites in southern parts of the CWA are already starting to see
some fog.
&&
.DISCUSSION...
Issued at 303 PM EDT Fri Aug 2 2024
- Thunderstorms exiting southeast tonight, dry Saturday
It looks increasingly likely that we will escape the heaviest
rain and precipitation will exit or dissipate rather quickly early
tonight.
We are seeing the development of a north to south oriented
convergence axis associated with the lake breeze front (LBF).
LBF convergence per surface observations is quite pronounced with
northwest flow west of the boundary and northeast flow to the
east of the boundary. The inland northeast flow is associated with
a stacked low centered over southeast Lower MI.
Recent HRRR runs indicate deep convection should form along the
LBF later this afternoon but activity should zip southward rather
quickly due to northerly mean flow in the cloud bearing layer.
This flow direction is associated with being located more west of
the stacked low instead of northwest of it. The low in question
is being well resolved by local VWPs, and at this writing its
center appears to be rather close to the TDTW Terminal Doppler
Weather Radar.
Given the progressive motion of this final bout of convection, locally
heavy rain is not a concern. This also is supported by low values
of 12Z HREF Prob Matched Mean (PMM) QPF in our forecast area.
Immediately southeast of the GRR forecast area, however, there is
considerably more concern for heavy rain as described in a recent
Mesoscale Precipitation Discussion (MPD) issued by WPC and
supported by the HREF PMM guidance.
It is still looking dry Saturday. Although temperatures will be
unseasonably warm in the upper 80s, things should feel considerably
less oppressive with dewpoints down into the mid 60s.
- Heavy rain potential Sunday night into Monday night, then cooler
There`s pretty good model agreement heading into next week in which
we`ll have an opportunity for another couple of rounds of
showers/storms and then cooler and less humid conditions during the
latter part of the week.
The upper flow over the next week will show a persistent trough over
the Canadian prairie provinces which will shoot short waves east
across the northern tier of the US in slight northwest flow.
Through Monday, We`ll see south flow continue to pump hot humid air
into the lower Great Lakes and that means another day in the
mid/upper 80s Sunday with very humid conditions, although the
weather should be dry. The warm temperatures will linger into
Sunday, and then we`ll begin to see a pattern change.
Models have been showing low pressure developing over the Missouri
Valley and then moving east in conjunction with a short wave exiting
the trough over Canada. A strong LLJ is progd to develop Sunday
night east of the low pointed at Lower MI. At the same time, a cold
front moving south from Canada will move into northern Lower. This
is typically a good combination for moderate to heavy rainfall from
training showers/storms and the models are showing that.
We`ll likely see one round of showers/storms Sunday night over the
northern cwa and a second round Monday night over the central cwa as
the frontal boundary continues to sink south.
Once the cold front is south of the cwa Tuesday night, cooler and
drier air will begin to flow into the region from Canada. H8 temps
near 18c Monday will fall to 4c by Friday as a second push of cooler
air is expected Thursday. Highs in the 70s and lows in the
refreshing 50s will be common after Tuesday.
&&
.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 804 PM EDT Fri Aug 2 2024
Showers and storms have exited the region. Expect VFR cigs and
vsbys through the first half of the overnight period. MKG, GRR
should have VFR continue through most of Saturday.
The biggest concern will be fog/mist overnight. LAN, JXN, AZO and
BTL could see MVFR to IFR cigs and vsbys after 04Z with AZO and
JXN potentially having LIFR between 09Z to 12Z. Conditions should
improve between 12Z to 14Z with VFR by 15Z at the latest.
&&
.MARINE...
Issued at 303 PM EDT Fri Aug 2 2024
Buoy obs and webcams indicate that winds and waves are staying
below levels of concern. The latest SRF products do advertise a
moderate risk for our southern zones and this may be a little on
the high side but not going to make any changes since things can
sometimes change quickly. Cloudiness over Lower MI combined with
farther inland penetration of the LBF are probably factors that
are preventing winds and waves from building too much.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...None.
&&
$$
UPDATE...MJS
DISCUSSION...04/TJT
AVIATION...Ceru
MARINE...TJT
Area Forecast Discussion
National Weather Service Indianapolis IN
1136 PM EDT Fri Aug 2 2024
.KEY MESSAGES...
- Clearing tonight with patchy fog overnight into early Saturday
morning
- Partly Cloudy and warm on Saturday
- Aside from patchy early AM fog this weekend...mainly rain-free, yet
humid and marginally hot conditions will continue into next week
&&
.FORECAST UPDATE...
Issued at 944 PM EDT Fri Aug 2 2024
Latest lightning data was not showing any activity across central
Indiana as LAPs and SPC mesoanalysis data was indicating decreasing
instability with the boundary cooling post sunset. Meanwhile, radar
data was only showing isolated cells over the lower Wabash Valley,
some still putting out moderate rainfall as PWATS were still on the
order of 1.6 inches which is above normal. Meanwhile, a larger area
of convection was pivoting southeast on the back side of the upper
low, which was moving east across west central Ohio per H20 vapor
imagery. The low will continue to move east and in additional to
nocturnal boundary layer cooling should put an end to the showers by
or shortly afternoon Midnight.
Fog and or low stratus could be an issue overnight based on small
temperature and dew point depression differences along with some
clearing associated with the ridge getting closer. Hi-RES soundings
indicate some drying aloft and in the boundary layer which should
mean the fog will be relatively shallow and should burn off shortly
after sunrise. Meanwhile, upstream dew points in light northwest low
level flow are not much if any lower, so temperatures will not fall
much lower than the upper 60s overnight. Will mention patchy fog in
the HWO but will hold off on headlines.
&&
.MESOSCALE UPDATE...
Issued at 702 PM EDT Fri Aug 2 2024
H20 vapor imagery was vividly showing the upper low spinning over
the Richmond, Indiana area early this evening. The low was
interacting with deep moisture (anomalous PWATs to 1.75 inches) per
Hi-Res soundings and strong instability with MLCAPES 1500 to 2000
J/kg to trigger isolated to scattered thunderstorms. These storms
were rotating counter clockwise around the low per radar
reflectivity mosaic. Look for the activity to continue at least for
awhile after sunset, and then as instability dies and the low moves
off to the east, so too will the storms by mid to late evening.
&&
.SHORT TERM (This evening through Saturday)...
Issued at 300 PM EDT Fri Aug 2 2024
Synopsis -
Surface analysis late this morning shows low pressure over Southern
Ontario, just north of Lake Erie. This was resulting in cyclonic
flow across Central Indiana. High pressure was found over NB/KS.
Water vapor imagery shows a deep upper low over Central Indiana.
Skies were mostly cloudy across Central Indiana. Dew points across
central Indiana remained very moist, in the upper 60s and lower 70s.
Radar shows scattered showers and storms popping across Central
Indiana and progressing southeast within the flow. Strong ridging
and subsidence was found upstream over the northern plains and
western Great Lakes.
This afternoon and evening -
Diurnal heating is expected to continue to fuel scattered showers
and thunderstorms into the early evening. ACARS soundings continue
to suggest favorable CAPE in place along with steep lapse rates as
convective temperatures are reached through the late afternoon.
Given the warm and humid air mass in place, a favorable set up
remains for convection this afternoon. HRRR remains in agreement,
suggesting scattered showers and storms across the area through 00Z-
02Z. Thus will continue to use high chance pops through 00Z-02Z,
particularly across the eastern parts of the forecast area, due to
proximity to the departing low.
Overnight -
The models suggest the upper low will push east of Central Indiana,
allowing the ridging aloft over the western Great Lakes to begin to
sag southward across Central Indiana. This will result in a
subsidence and drying trend as seen within the forecast soundings.
Any rain chances will be lost as forcing is lost with the departing
low and lack of heating. Thus overnight skies are expected to show
signs of decreasing cloudiness. As the previously mentioned surface
high over the plains builds eastward, northerly lower level flow is
expected. Only minor change in dew points are expected overnight as
they fall to the mid 60s. Thus overnight lows in the lower to mid
60s will be expected. Patchy fog will be possible particularly in
rural areas as dew point depressions fall to less than 1-2F.
Saturday -
Forecast soundings on Saturday trend toward a dry column through the
day with attainable convective temperatures. Models suggest strong
ridging building aloft which will lead to subsidence. This effect
can be seen within the very dry forecast soundings within the middle
and upper levels. Thus only partly cloudy skies will be expected due
to a few CU clouds. 850MB temps will remain quite warm, around 15C.
This will allow for highs on Saturday to reach the upper 80s to
around 90.
&&
.LONG TERM (Saturday night through Friday)...
Issued at 302 PM EDT Fri Aug 2 2024
Saturday night through Monday...
The rest of the weekend will continue the short term`s trend to an
overall less-active pattern as broad yet very weak surface high
pressure crosses the Midwest. More reasonable precipitable water
values closer to 1.25 inches and lack of forcing will promote
widespread rain-free conditions. However, the subtropical ridge
prevailing through the western two-thirds of the CONUS will extend
its more zonal/eastern portions into the Midwest...which will
maintain higher humidity with overnight lows between 65-70F.
Slight moderation of daytime readings is expected as weak low
pressure approaching to our north-northwest promotes light
southwesterly breezes, with highs nudging upward from mainly upper
80s to lower 90s. Heat Index values may briefly exceed 100F Monday
afternoon south of Interstate 70 under abundant sunshine, although
Heat Advisory criteria is not expected to be reached at this time.
Equally impactful may be areas of notable visibility reduction in
pre-dawn fog over portions of the region that have recently seen
heavy rains.
Tuesday through Friday...
The rest of the next work week will see a slow/modest trend to lower
heights and back to near-normal late summer conditions...as broad
troughiness that has been contained to central Canada shift
southward to the far-north central CONUS. While this will not
likely bring central Indiana the autumnal conditions expected for
the Upper Midwest...following a second marginally hot day on
Tuesday, widespread low 80s will hopefully be the rule for latter
portions of the long term as the southern extent of amplified
Canadian high pressure spills into the Midwest. While overall dry
conditions are expected to continue, widely scattered showers/storms
could accompany this transition...especially towards the southern
Great Lakes where better forcing will follow the main cool frontal
zone push.
&&
.AVIATION (06Z TAF Issuance)...
Issued at 1136 PM EDT Fri Aug 2 2024
Impacts:
- Reduced visibility from fog early Saturday morning
Discussion:
Air mass change has been minimal and the lower troposphere is still
moist. With light/calm winds and clear conditions, patchy/shallow
fog, potentially locally dense is expected. This will diminish by
around 1230-1300z.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE...MK
SHORT TERM...Puma
LONG TERM...AGM
AVIATION...BRB
Area Forecast Discussion
National Weather Service Morristown TN
1147 PM EDT Fri Aug 2 2024
...New UPDATE...
.UPDATE...
Issued at 1145 PM EDT Fri Aug 2 2024
Looks like one more round of scattered showers and storms across
the southern and extreme northern sections of the forecast area
with some brief heavy rainfall in southwest Virginia and some more
in southeast Tennessee ahead of a cold front moving slowly east
from middle Tennessee late this evening. Cancelled the Flood Watch
a little early over the northern two thirds of the region. A few
more hours of convection ahead of the front tonight so increased
chances in the southwest where they were too low to match current
activity. Patchy fog forms later tonight if cloud cover decreases
enough. Updated forecast has been sent.
&&
.UPDATE...
Issued at 830 PM EDT Fri Aug 2 2024
Updated forecast and extended flood watch until midnight for
northern two thirds of the forecast area. Still scattered showers
and storms moving across parts of the area but beginning to
decrease in coverage. The stronger storms the last few hours have
begun to decrease in intensity. Still getting some high rain
rates near an inch or more per hour causing flooding in northern
Tennessee. This will decrease in the next couple hours as heating
ends. The cold front is slowly moving into east Tennessee but
showers and storms should continue ahead of it through the
evening. some patchy fog should form later tonight as precipitation
ends and some clearing occurs. Updated forecast sent.
&&
.SHORT TERM...
(This evening through Saturday)
Issued at 301 PM EDT Fri Aug 2 2024
Key Messages:
1. Scattered to widespread showers and storms through this evening.
At least a few isolated strong to severe storms are likely. The main
threats are damaging straight line winds and localized flooding.
2. A few isolated showers and storms persist through the overnight
hours.
3. Isolated to scattered showers and storms again tomorrow, best
chances east of I-75. A few marginally strong storms possible but
severe weather is not expected.
Discussion:
Unseasonably strong shortwave is currently moving through the
Ohio River Valley this afternoon. This shortwave and associated
cold front, along with an unstable and moisture rich environment,
has allowed scattered to widespread showers and storms to develop
this afternoon. RAP/HREF instability show around 2000 to 2500 J/kg
of MLCAPE currently in place with roughly 20 to 30kts of
effective shear. Though the better shear is generally along and
north of I-40. Due to low-end shear, expect only semi-organized
storms. In addition to the high MLCAPE, DCAPE values are roughly
1200 J/kg, which is high. This environment will support at least
a few strong to severe storms through this evening. The main
threats will be damaging straight line winds and localized
flooding. Due to the high PWs and intense rainfall rates,
isolated locations could see anywhere from 1 to 3 inches of
rainfall through this evening, especially with any training
thunderstorms. HRRR shows the highest coverage of precip from
roughly 21Z to 01Z. Coverage of showers and storms decreases
through the overnight hours but isolated activity will likely
persist through the night. At least some cloud cover will likely
hang around through the overnight hours. Areas that receive rain
today and are able to clear out overnight will likely see fog.
The trough axis will remain centered across our area tomorrow. The
cold front will likely not pass to our east until the afternoon/evening
hours. Expect showers and storms to be around as early as sunrise
and remain in place throughout the day. As we progress later in
the day the higher pops should shift east of I-75 as the cold
front pushes east. A few marginally strong storms are possible
but severe weather is not expected.
&&
.LONG TERM...
(Saturday night through next Friday)
Issued at 301 PM EDT Fri Aug 2 2024
Key Messages:
1. Drier weather expected for the long term.
2. Near normal temperatures Sunday, then above normal temperatures
expected for Monday through at least Wednesday.
Discussion:
We start the period with the upper trough axis over our area and an
upper ridge to our west. A few showers or a thunderstorm may linger
into early Saturday night before ending as the trough axis exits
east.
Heights will be rising Sunday into Monday as the upper ridging
builds in from the west. Models have some disagreement for the
latter periods, but generally show heights starting to fall again
during the mid to late work week and a tropical system is forecast
to be moving up near the East Coast but well to our east. The
atmosphere is forecast to be drier for the long term period, with
much less convection expected than in recent days. Will not argue
much with the NBM which has low PoPs each day primarily over and
near the eastern higher terrain areas.
After starting out with near normal temperatures Sunday, a warming
trend is expected early in the week with above normal temperatures
for the Monday through at least Wednesday time frame and perhaps
through the end of the period.
&&
.AVIATION...
(00Z TAFS)
Issued at 745 PM EDT Fri Aug 2 2024
Scattered showers and storms will continue through the next few
hours this evening with mostly VFR conditions. Brief MVFR
conditions could occur at CHA and TRI with passing showers and
storms. Less likely at TYS. Brief strong and gusty winds expected
with any stronger storms. MVFR CIGs expected at all three sites
early Saturday morning, with additional showers and storms in the
morning at TYS and afternoon at all three sites.
&&
.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN 72 89 70 92 / 30 30 10 10
Knoxville McGhee Tyson Airport, TN 70 86 68 90 / 80 60 10 10
Oak Ridge, TN 70 85 69 90 / 50 50 10 10
Tri Cities Airport, TN 68 83 66 87 / 60 70 20 20
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
SHORT TERM...TD
LONG TERM....DGS
AVIATION...TD
Area Forecast Discussion
National Weather Service Pocatello ID
146 PM MDT Fri Aug 2 2024
.SHORT TERM...Today and Saturday.
The high pressure ridge axis is directly over southeast Idaho
today. The ridge axis moves slightly east by Saturday and weak
southwest flow aloft sets up over the area allowing monsoon
moisture to start to move into the area by late Saturday.
Expect temperatures 5 to 10 degrees above normal today and, to a
lesser degree, Saturday. Temperatures will run in the mid to
upper 90s with a few areas hitting 100 degrees today and Saturday
afternoon. By Saturday afternoon, clouds will move across our
area, which will likely drop down temperatures a few degrees.
Later Saturday afternoon into the evening, monsoon moisture moves
across our western areas, especially our northwest areas,
allowing for scattered showers and isolated thunderstorms.
As for smoke, southwesterly flow aloft will filter in increased
concentrations of smoke and, therefore, we continue to carry
patchy smoke in the forecast for the next couple of days.
Wyatt
.LONG TERM...Sunday through Next Friday.
Temperatures will cool slightly and the chance for showers and
storms will increase a bit on Sunday as a weak shortwave passes
through the area. The best chance for precip will be in the higher
elevations of the Central Mountains and Eastern Highlands. In fact,
there`s about a 10 percent chance of at least a tenth of an inch of
QPF in there areas on Sunday afternoon. While it`s not a lot, it`s
more than the dry conditions we`ve experienced through most of the
week so far. It will still be hot on Sunday, but highs will have
fallen to the low to mid 90s through most of the eastern Magic
Valley, Snake Plain, and valley locations in the South Hills. Winds
will also begin to pick up on Sunday afternoon with gusts in the 20
to almost 30 mph range in the lower elevations. The limited
afternoon monsoon moisture, breezy winds, and highs in the 90s will
continue through most of next week.
AMM
&&
.AVIATION...18Z Friday through 18Z Saturday.
We continue with VFR conditions due to high pressure over the area
keeping us dry through today with light and variable winds. The HRRR
Smoke forecast continue to show the next wave of wildfire smoke
arriving this afternoon. The HRRR does not show any impacts to VIS,
which still seems a bit off, but will keep the 6SM FU/HZ in the
forecast. Monsoonal moisture makes its return this weekend, but rain
and storm chances remain low (less than 20 percent) on Saturday.
AMM
&&
.FIRE WEATHER...The forecast has not changed. High pressure will
dominate the area through late Saturday. Look for hot, dry and,
unstable conditions today through most of Saturday afternoon. By
late Saturday afternoon into the Saturday evening, monsoon
moisture will move back into the area. Isolated thunderstorms are
possible late Saturday, mainly across the Sawtooth, Salmon-
Challis, and Eastern Magic Valley. Isolated to scattered
thunderstorms are more likely Sunday, Monday, and Tuesday as the
high pressure ridging starts to break down with a trough working
its way through the area. Winds will pick back up late Tuesday and
Wednesday as a trough looks to move through the area late Tuesday
into Wednesday. Wednesday afternoon look for dry conditions and
gusty winds across mainly our northern areas, including fire zones
410, 422, 475, and 476. Also, temperatures look to start to drop
down next week, especially by the end of the week.
Wyatt
&&
.AIR QUALITY...Regional wildfires continue to impact air quality
over Southeast Idaho with increased concentrations of smoke expected
to filter into the region in southwest flow. We continue to carry
patchy smoke in the forecast over the next two days, during which
the Idaho DEQ is forecasting "Moderate" air quality.
Cropp
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
Heat Advisory until 9 PM MDT Saturday for IDZ051>059-061-062-065-
067-075.
&&
$$
Area Forecast Discussion
National Weather Service Reno NV
213 PM PDT Fri Aug 2 2024
.SYNOPSIS...
* Shower and thunderstorm chances increase this afternoon into
Saturday, with a few overnight storms possible.
* Smoke from ongoing wildfires will impact areas mainly north of
I-80 at times through this weekend.
* After slight cooling Saturday, above average temperatures return
Sunday through next week.
&&
.DISCUSSION...
THUNDERSTORMS TODAY THROUGH THIS WEEKEND:
* An upper level shortwave moving northward from southern
California into Oregon will bring shower and thunderstorm
chances (30-60%) this afternoon through Saturday. Moisture will
increase with PW values between 0.80 and 1.10", with surface dew
points increasing into the 40s to near 50 degrees. Despite this
increase in moisture, residual dryness in the sub-cloud layer
and relatively fast storm motions of 20-30 mph will keep the
possibility of isolated dry lightning strikes. This afternoon,
storms are expected to initiate over Mono-Mineral counties and
move northwest into the Tahoe basin and parts of western NV
mainly south of US-50. Upper level forcing and elevated
instability with the northward moving shortwave will allow for
formation of showers with embedded lightning overnight into
early Saturday morning in similar areas of the Sierra and
western NV south of US-50.
* Then by early Saturday afternoon, another round of storms is
projected to form near the Sierra and spread into western NV by
mid-late afternoon, bringing the best chance for precip for the
upcoming week in the main urban areas including Reno/Sparks-
Carson City. An additional focus for thunderstorms Saturday
afternoon will set up over northeast CA-far northwest NV, with
potential for a few stronger and more organized cells in these
areas due to enhanced forcing associated with the ejecting
shortwave. These storms are expected to exit northeast
CA/western NV by mid-late Saturday evening.
* Other than a small 10-20% chance of storms Sunday afternoon in
Mono-Mineral-southern Lyon counties, the thunder risk drops to
10% or less for much of next week. Some of the medium range
guidance indicates potential for isolated storms returning later
next week for Mono-Mineral counties, but confidence is low due
to variations in the upper level ridge/trough pattern presented
by the ensemble data over these areas.
SMOKE AND HAZE:
* Smoke and haze from the Park Fire will continue to affect
northeast California and western Nevada into the weekend,
although many areas have seen some improvement in air quality
today as winds over the fire were directing smoke more northward
into north central CA. HRRR smoke model guidance is showing some
west winds returning to the fire later today, so smoke could
return to parts of northeast CA/northwest-west central NV
tonight-Saturday AM.
* The increased precip chances and southeast winds ahead of the
shortwave passage could provide a temporary break in additional
smoke reaching these areas during the day Saturday, before a
SW-W flow returns Saturday evening and Sunday which would
increase the risk of smoke from the Park Fire returning to
similar parts of northeast CA/northwest-west central NV.
ABOVE AVERAGE TEMPERATURES SUNDAY ONWARD:
* Saturday will be a few degrees cooler than recent days due to
increased cloud cover along with thunderstorm chances. Then as
the upper level ridge rebuilds over the Four Corners region and
extends westward across much of the Great Basin, we`ll see
temperatures warm up to the upper 90s-near 100 degrees in
western NV valleys from Sunday through much of next week, about
3-6 degrees above early August averages with moderate HeatRisk
prevailing.
* These temperatures may edge slightly downward by later next
week, as the majority of the longer range ensemble guidance
shows the western extent of the ridge eroding in response to a
bit more troughing over the Pacific NW and far northern CA.
MJD
&&
.AVIATION...
* Scattered showers and t-storms develop in the eastern Sierra and
western NV mainly south of US-50 this afternoon and evening,
with another round overnight into Saturday AM in similar areas.
A few storms could edge northward across the Tahoe basin and
parts of northeast CA from these two periods of convective
activity, with most cells moving northwest around 20-25 kts.
* Showers and a 10-15% chance of storms Saturday morning will
increase Saturday afternoon. Best chances (40-60% chance) will
be across northwest-far western NV and northeast CA with storms
pushing off the Sierra by mid afternoon, as south-southwest
flow increases.
* Short periods of MVFR/IFR conditions from brief heavy rain
and/or small hail, lightning, and gusty winds to 30-35 kts are
all possible with stronger cells today through Saturday.
* Density altitude impacts are possible again this afternoon and
Sunday for western NV terminals with highs near 100 degrees, but
should ease Saturday when temperatures dip several degrees due
to increased cloud cover and shower/thunder chances. MJD
&&
.FIRE WEATHER...
* T-storm threat increases this afternoon through Saturday (30-60%
chance) with a majority of storms capable of producing wetting
rainfall. Showers with isolated embedded lightning are also
expected to develop late tonight into Saturday morning for the
eastern Sierra and western NV mainly south of US-50.
* Some storms will be capable of heavy rainfall, especially if
cells anchor on the terrain or train over the same areas. At the
same time, storm motions will be relatively quick (20-30 mph),
shifting from a northwest motion to mainly north-northeast by
Saturday afternoon. This brings the potential for new lightning
fire ignitions outside of the main precipitation cores. Gusty
outflow winds up to 40 mph are also in the mix, with stronger
gusts to 50 mph possible with Saturday`s storms especially in
far northeast CA-northwest NV. MJD
&&
.REV Watches/Warnings/Advisories...
NV...None.
CA...None.
&&
$$
Area Forecast Discussion
National Weather Service Blacksburg VA
813 PM EDT Fri Aug 2 2024
.SYNOPSIS...
An upper disturbance approaches the area this evening which is
going to help develop scattered storms. Saturday will have the
highest probability of precipitation as a cold front crosses the
area. At this point Monday has the potential to be the driest
day next week.
&&
.NEAR TERM /THROUGH SATURDAY/...
As of 745 PM EDT Friday...
Storms have decreased in both coverage and intensity this
evening as much of the area has been worked over fairly well.
Cloud cover has lingered, thus recovery was very limited. RAP
analysis shows a rather stable area in the wake of the
departing storms to the east. Some ongoing convection across
western North Carolina may continue for a few more hours and
move north into NW NC, but severe threat will be very limited
with heavy rain being the main threat.
Areas of fog overnight, especially in locations where downpours
occurred earlier today.
As of 125 PM EDT Friday...
Key message:
- Heat advisory through early evening in the Piedmont
- Scattered thunderstorms this afternoon, some may be
strong/severe.
- Better coverage of showers/storms Saturday, severe threat
marginal east of the Blue Ridge
Convection has fired up across the southern Blue Ridge with
storms moving into WV/SW VA of a vort in eastern KY. Most storms
are moving 15-30 mph, but some backbuilding observed along the
southern Blue Ridge, with rainfall rated 3-4"/hr, so will have
to watch for localized flooding thanks to this and pwats
1.5-1.8".
Followed close to a blend of 16z HRRR/NBM/Hi-ResARW through this
evening, then leaned toward GFS/NBM/HREF late tonight-Saturday.
This leads to scattered to numerous storms this
afternoon/evening higher coverage in the mountains.
With a decent shortwave and southwest flow into tonight, not
really seeing an end to shower/storm chances overnight but do
cut pops back to low to slight chance, before upticking through
the day Saturday, where better upper dynamics and PVA will
enhance coverage ahead of cold front, with likely pops majority
of the area.
There is a severe threat, but cloud cover may be more prominent
Saturday which could limit this. Marginal risk of damaging winds
still possible east of the mountains. Storms again should be
moving along but training of storms could lead to localized
flooding.
Temperatures tonight will drop into the 60s in the mountains to
lower 70s east. Not as warm/hot Saturday with more coverage of
storms/clouds with upper 80s east to upper 70s to lower 80s
west.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
As of 1240 PM EDT Friday...
Key Messages:
1) Confidence is high for chances of showers and thunderstorms to
gradually decrease to start the new week.
2) Temperatures will nudge upward a little on Monday.
An upper level trough should head eastward toward the East Coast
during Saturday night into Sunday. The chances of scattered showers
and thunderstorms will slowly wane as the threat of convection
shifts eastward over time. Any activity will eventually end by
Sunday night as weak high pressure arrives from the northwest to
bring slightly drier air. Model agreement is starting to improve on
the track of a potential tropical cyclone moving across Florida on
Sunday night and paralleling the coastline from Georgia to North
Carolina during Monday and Monday night. With the Mid Atlantic
staying on the western side of this cyclone, the extra subsidence
could keep most locations dry. Compared to Sunday, temperatures may
rise a couple degrees by Monday from the additional sunshine.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
As of 1240 PM EDT Friday...
Key Messages:
1) Confidence is moderate for drier weather on Tuesday.
2) The chance of showers and thunderstorms may slowly increase
during the remainder of the week.
A potential tropical cyclone may be situated off the North Carolina
coastline by Tuesday and continue to parallel the East Coast towards
the New England states later in the work week. Meanwhile, subsidence
from the western side of this cyclone could keep conditions drier
across the Mid Atlantic. An upper level trough may move across the
Great Lakes to slowly increase the chance of afternoon showers and
thunderstorms for the remainder of the week. This trough will also
help to steer the potential tropical cyclone away from the East
Coast as the work week concludes. Temperatures overall in this
forecast period will stay near or just above normal.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
As of 745 PM EDT Friday...
Storms are going to linger at times through tonight but
should be lesser coverage so not going to have any in the tafs
at this point. Again, unsure on fog/low clouds as cloud cover
may limit this but did have some put in at LWB/BCB, leaning
toward IFR 2sm.
Showers/storms will become more numerous Saturday but mainly in
the afternoon. Added VCTS in all sites except for western
mountains (BLF/LWB).
Average confidence for ceiling, visibility, and wind.
Below average confidence for the location of thunderstorms.
Extended Aviation Outlook...
Showers/storms are expected to diminish Sat night into Sunday
but still potential for sub-VFR with storms and any fog/low
clouds at night. precipitation Sunday into Monday.
Looking dry at the moment Monday-Tuesday with VFR outside of
late night/early morning fog at LWB/BCB. Potential for tropical
impacts mid to late week especially if you are flying along the
eastern seaboard.
&&
.CLIMATE...
As of 250 AM EDT Friday...
Here are the August 2nd warmest minimum temperatures for our
local climate sites, along with the year they were set.
Bluefield WV.....71 (2006)
Danville VA......79 (1924)
Lynchburg VA.....73 (2020)
Roanoke VA.......74 (2022)
Blacksburg VA....69 (1933)
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...None.
NC...None.
WV...None.
&&
$$
SYNOPSIS...AMS/WP
NEAR TERM...BMG/WP
SHORT TERM...PW
LONG TERM...PW
AVIATION...AMS/BMG/WP
CLIMATE...AMS
Area Forecast Discussion
National Weather Service Great Falls MT
835 PM MDT Fri Aug 2 2024
.SYNOPSIS...
Warm temperatures continue across North Central and Southwestern
Montana today and tomorrow, with most lower elevation locations
seeing temperatures in the 90s to near 100. Cooler and unsettled
weather is on tap for next week, with highs gradually falling into
the 60s and 70s with near daily chances for showers and
thunderstorms.
&&
.UPDATE...
The overall going forecast is on track. Some minor adjustments
were made to the precipitation chances for tomorrow afternoon
based on updated model guidance. The latest HRRR smoke was also
added in which expanded haze coverage by a bit. In general,
tomorrow is expected to be a hazy/smoky day for most of central
and southwestern Montana. Significant reductions in visibility due
to smoke are not expected except in the immediate vicinity of
wildfires. -thor
&&
.AVIATION...
03/00Z TAF Period
VFR conditions will prevail across all terminals; however, haze
across portions of Southwest and North Central Montana is likely to
reduce slantwise visibility upon ascent/descent over the next 24
hours. A weak cold front/boundary will bring a wind shift to the
north across most terminals through the early evening hours, with
the breeziest conditions expected along the eastern slopes of the
Rocky Mountain Front and along portions of the hi-line through the
evening. After 03/06Z, winds will be generally light across much of
the region with the exception of some breezy conditions possible
tomorrow afternoon for KHVR. - Moldan/thor
Equipment Note: The KEKS sensor is currently inoperable and, as a
result, no amendments are scheduled until further notice.
Refer to weather.gov/zlc for more detailed regional aviation weather
and hazard information.
&&
.PREV DISCUSSION...
/ISSUED 536 PM MDT Fri Aug 2 2024/
Key Points:
-Warmth continues through Saturday
-Gradually turning cooler next week with periods of rain showers
and thunderstorms
Short term (through Saturday)... Upper level ridging will
continue to remain parked over the Northern Rockies through the
next 36 to 48 hours, keeping warm temperatures and generally
tranquil conditions in place. Expect high temperatures to reach
the mid to upper 90s today and Saturday, with a few places seeing
highs briefly touch 100 degrees either day. The ridge will also
keep skies nearly perfectly clear today and through tomorrow
morning, though some high clouds and even a few rain showers will
begin to develop tomorrow afternoon and evening as an embedded
shortwave pushes in from the southwest.
Extended (Sunday through next Friday)... The upper level ridge
across the western US will gradually give way to broad upper level
troughing by the end of the week. As this transition happens,
temperatures will gradually fall through the week, with two main
drops in temperature Saturday to Sunday and again Tuesday to
Wednesday. With this transition to upper level troughing,
afternoon showers and thunderstorms will be common, particularly
Sunday and Tuesday, as surges of cooler air work their way into
the area. While it is still a bit early, models indicate that
there will be sufficient shear to support and dry air in the mixed
layer to allow for at least some strong wind gusts and small
hail, though I will hold off on mentioning these in the grids for
now. While not a classic Montana severe setup, this is at least
somewhat reminiscent of low cape/high shear environments that are
capable of squeezing out a few stronger storms. Ludwig
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 62 101 65 82 / 0 10 20 50
CTB 58 97 61 77 / 0 10 30 60
HLN 63 103 68 87 / 0 10 20 60
BZN 57 100 60 89 / 0 0 10 60
WYS 45 90 50 83 / 0 0 10 60
DLN 56 94 59 85 / 0 10 10 50
HVR 61 101 65 86 / 0 10 40 50
LWT 58 96 61 83 / 0 0 20 60
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
http://www.weather.gov/greatfalls
Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
803 PM MDT Fri Aug 2 2024
.KEY MESSAGES...
- Hot/mainly dry weather continues into the weekend, with elevated
fire-weather conditions and heat indices above 100F.
- More unsettled and becoming cooler late this weekend and
early next week.
- Even cooler weather is expected toward late next week with daily
chances for showers and thunderstorms.
&&
.UPDATE...
Issued at 655 PM MDT Fri Aug 2 2024
Heat indices have fallen below 100 degrees, and will continue to
fall this evening. Have allowed the Heat Advisory to expire.
&&
.DISCUSSION...(This Evening Through Friday)
Issued at 212 PM MDT Fri Aug 2 2024
Current surface analysis shows a weak trough over eastern WY with
an overall diffuse pressure pattern. Water vapor and 500-mb RAP
analysis have a broad ridge over the western CONUS with a high
centered near the Four Corners area. Skies are sunny across most
of the CWA, but with flat cumulus over northeastern WY and far
southern SD, along with slightly more agitated cumulus over the
BLKHLS. LightningCast showed a small chance of a thunderstorm
developing over the BLKHLS, but with MLCAPE less than 250 J/kg
this will be very marginal/isolated. Temperatures have reached
the lower 100s in west-central SD where the heat advisory is in
effect until 7 pm MDT.
Warmer air will continue over the area through Saturday night --
lingering over much of the area into Sunday -- as the upper ridge
maintains itself over the Rockies and the Great Basin. Highs will
reach the upper 90s to above 100 degrees across much of the
plains again Saturday. Another heat advisory likely will be
needed for portions of the western/central SD plains on Saturday.
The HRRR smoke model is hinting at haze returning to the area
Saturday afternoon, so if that trend continues will need to add
mention of that to the forecast. Otherwise, a dry air mass will be
in place with RH values dropping into the 10-20 percent range
across northeastern WY and much of western SD Saturday afternoon
(and again Sunday afternoon over the southwestern CWA). Winds will
remain relatively light for most of the area, but picking up a
little bit late Saturday afternoon as a weak front approaches from
the north. Chances for showers/storms should stay east of the CWA
through Saturday evening.
A back-door cool front gradually moves southward into the area
Saturday night and Sunday, likely stalling out across southern
portions of the forecast area later Sunday/Sunday night. Chances
for showers and thunderstorms should increase across northern
portions of the forecast area late Saturday night/Sunday morning,
but there will be an ill-timed short-wave during the day. The
effect will be for the best chance of showers/storms to be delayed
until Sunday evening and overnight as a second short-wave passes
through the CWA. Would expect storms to start late in the day on
Sunday in northeastern WY, and then move eastward through the
evening. Stout capping may come into play, but sufficient CAPE and
shear along and north of the stalled out frontal boundary would
support potential for at least marginally severe storms across
portions of northeastern WY and western SD.
Highs on Sunday will also depend on where the front stalls out
over the area, but should generally range from around 90 across
far northwestern SD and the Black Hills to possibly 100-105 over
far southwestern SD. Monday and possibly Tuesday should be
slightly cooler overall. The ridge to the west starts to break
down by mid-week, allowing at least weak short-wave troughs to
pass through the northern/central Plains. Monday through the first
part of Tuesday should be relatively quiet, but then better
chances of showers/storms arrive Tuesday night (highlighted by the
GEFS M-climate).
A strong upper trough is expected to move across western Canada mid
to late week, eventually displacing the ridge over the western US.
This system will bring even cooler air and a fairly high likelihood
for below-average temperatures late week (above 60 percent for
most of the area). The exact track of the system later next week
is rather uncertain right now, but will impact our rain/storm
chances -- as well as how cool the area gets toward the end of
the week.
&&
.AVIATION...(For the 00Z TAFS Through 00Z Saturday Evening)
Issued At 802 PM MDT Fri Aug 2 2024
VFR conditions will continue through the period. Skies will become
increasingly hazy as smoke drifts in from the northwest again.
&&
.FIRE WEATHER...
Issued At 212 PM MDT Fri Aug 2 2024
Elevated fire-weather conditions will continue through Saturday
and possibly into Sunday for northeastern WY and much of western
SD as high temperatures rise into the upper 90s and lower 100s on
the plains. Minimal, if any, precipitation will occur through
Saturday evening. The dry air mass will remain in place across
these areas, with relative humidities dropping into the 10-15
percent range across northeastern WY and around 15 percent for
much of western SD each day (especially Saturday). Winds look to
remain relatively light in most areas through Saturday, with gusts
less than 20 mph, except for northwestern SD Saturday afternoon.
Thus, some areas of near-critical fire-weather conditions could
develop on Saturday afternoon in this area (as a weak cold front
approaches). Will hold off on a watch at this time because it does
look marginal. For example, the hot-dry-windy index has only low
chances (less than 50 percent) of exceeding the 90th percentile
on Saturday, and virtually no chance of this on Sunday.
Otherwise, some lower temperatures, higher humidities, and
chances for showers and thunderstorms are expected across much of
the area Sunday night. However, some elevated fire-weather
conditions could persist over northeastern WY into far
southwestern SD on Sunday. Finally, a cooler and wetter pattern is
anticipated for Tuesday night through the end of next week.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...None.
WY...None.
&&
$$
UPDATE...Pojorlie
DISCUSSION/KEY MESSAGES...Bunkers
AVIATION...Pojorlie
FIRE WEATHER...Bunkers