Forecast Discussions mentioning any of "ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 08/01/22

Area Forecast Discussion

National Weather Service Denver/Boulder CO

 812 PM MDT Sun Jul 31 2022

.UPDATE...
Issued at 812 PM MDT Sun Jul 31 2022

Showers and storms are almost over already as the airmass
stabilizes with some warming and drying aloft. We`ll see isolated
precipitation over the eastern plains and in the mountains last
for another hour or so, and then mostly clear skies overnight.
Forecast is on track for Monday with warmer temperatures (mid to
upper 90s across the plains), and isolated to scattered high based
convection with gusty winds and light rain in/near the mountains.

&&

.SHORT TERM...(This evening through Monday)
Issued at 157 PM MDT Sun Jul 31 2022

The upper level ridge that extends into the four corners area has
pushed slightly north over the last 12 hours bringing increased
moisture to the region. PW values increased slightly from yesterday
with values close to 0.9 inches. Currently, MLCAPE values range from
400 to 700 joules for the higher terrain and urban corridor with
closer to 1000 for the eastern plains. ACARs soundings show an
inverted-V profile with high-based convection mainly bringing gusty
winds and light to moderate rain to the lower elevations. These
storms will be able to put down up to a half an inch in a short
period of time for the higher elevations so will maintain a limited
threat for burn scars. Storms will dissipate with the loss of
sunlight with overnight temperatures in the 60s for the plains and
40s to 50s in the mountains.

The ridge continues to strengthen Monday with less CAPE than today
and weak shear. Storms will be more isolated with light to moderate
rain, lightning, and gusty winds possible. Model soundings show dry
low levels with DCAPE values over 1000 joules that would bring more
of a gusty wind threat for the lower elevations with the stronger
storms. Highs will be in the mid to upper 90s with 60s to 70s in the
high country.

.LONG TERM...(Monday night through Sunday)
Issued at 157 PM MDT Sun Jul 31 2022

Monday night, upper level high pressure will be over the Central and
Southern Rockies with the center over Eastern Arizona and Western
New Mexico. Mostly dry conditons are expected across the forecast
area, with the exception of isolated showers and storms across the
mountains. Tuesday and Tuesday night, the upper ridge flattens in
response to an upper level shortwave moving across the Northern
Rockies and Great Plains States. Lift and moisture convergence along
a weak cool front associated with the shortwave may help kick off
some showers and storms across the plains as it moves across
Northeastern Colorado Tuesday evening. Across the mountains, there
should be enough residual monsoonal moisture trapped under the ridge
combined with daytime heating to produce scattered afternoon and
evening showers and storms. Behind the front, Wednesday`s max
temperatures on the plains should be somewhat cooler with highs in
the upper 80s to lower 90s.

For Thursday through Saturday there is some uncertainty in the
forecast due to run to run model inconsistencies. Many of the
deterministic and ensemble members are showing the upper ridge
building over Colorado which is considerably different than
yesterday`s 12Z runs. Previous runs showed the upper high shifting
eastward across the Central Plains States with a decent plume of
monsoonal moisture moving across all of the CWA. With the ridge over
the forecast area, the plume would tend to stay over the western
half of Colorado keeping most of the showers and storms in the high
country with drier conditions further east across the plains. With
plenty of available moisture and some instability to work with,(700-
500 mb Specific Humidity of 6.50-7.50 g/kg and CAPE values between
400-700 J/KG) there will be the potential for locally heavy rainfall
in the high country with some flash flooding possible, especially in
and near the burn scars. In addition, this pattern would result in a
continuation of above normal temperatures on the plains with daytime
readings climbing into the middle to upper 90s each day.

Late Saturday into Sunday, models are hinting at another shortwave
moving across the Northern Rockies and Plains States which may send
another weak cool front across Northeastern Colorado. This may lead
to better precipitation chances across the plains over the weekend
with slightly cooler temperatures by Sunday.

&&

.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 557 PM MDT Sun Jul 31 2022

Thunderstorm threat has diminished this evening, but a lone shower
still possible 01Z-02Z shortly behind a southerly wind shift. VFR
conditions will persist through Monday, with fairly normal diurnal
wind patterns once the southerly wind shift arrives. High based
convection could bring some gusty and variable winds to the TAF
sites after 19Z-20Z Monday, but threat of -TSRA is quite low given
an overall drier and more stable airmass.


&&

.HYDROLOGY...
Issued at 157 PM MDT Sun Jul 31 2022

Isolated showers and storms will be possible on Monday starting in
the afternoon and continuing into the evening hours. Conditions will
be slightly more stable with weak shear so storms will not be as
strong. Storms will still be capable of producing some light
rainfall but the risk of flash flooding is lower.

Scattered to numerous showers are expected across the high county
Tuesday through Sunday. Some of the storms will be capable of
locally heavy rainfall with a limited potential for flash flooding
in and near the burn areas each day.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

UPDATE...Barjenbruch
SHORT TERM...Bowen
LONG TERM...jk
AVIATION...Barjenbruch
HYDROLOGY...Bowen/jk



Area Forecast Discussion

National Weather Service North Platte NE

 538 PM CDT Sun Jul 31 2022

.SYNOPSIS...
Issued at 335 PM CDT Sun Jul 31 2022

H5 analysis from earlier this morning had an elongated area of
high pressure, which extended from northern Nevada, east southeast
toward Texas, then east toward Georgia and South Carolina. Closed
low pressure was of the coast of northern California. Further
east, a tandem of shortwave troughs were noted. The first was over
southern Manitoba and a second was noted over Indiana. In
association with the elongated area of high pressure, weaker
shortwaves were noted over Oklahoma and southern Wyoming. At the
surface, a weak frontal boundary had pushed south through the
northern half of the forecast area. This feature has pretty much
stalled along a line from Lewellen to Broken Bow. With the
exception of some "agitated" cu and altocu along this frontal
boundary, skies were mainly clear across the forecast area this
afternoon. There was some smoke off to the west of North Platte
this afternoon. This was in association with the fires south of
Scottsbluff. Readings as of 3 PM CT, ranged from 88 at Broken Bow
to 98 at Ogallala.

&&

.SHORT TERM...(This evening through Monday night)
Issued at 335 PM CDT Sun Jul 31 2022

Precipitation chances are the main forecast challenge in the near
term. For tonight into Monday morning, there are two areas of
concern for thunderstorms the first is along the frontal boundary
this evening, and the second is across north central Nebraska
later tonight. For the first area: The latest CAMS continue to
indicate isolated storm initiation INVOF the front, in the 4 to 6
PM CT time frame and feel confident enough to continue to mention
this in this forecast package. As for the severe threat, wasn`t
overly impressed with the degree and coverage of severe storms
early this evening. Initial severe mode appeared to be strong
winds given the decent amount of DCAPE present this evening. Upon
further investigation, feel there is some threat of large hail
there as well. Mid level-H700 computed capes are 1500 J/KG around
00z this evening INVOF the front. This coupled with deep layer
shear of 25-30 KTS should be ample to support some large hail.
With this in mind, will add the hail threat to the latest HWO to
go out this afternoon. The threat for storms in SW Nebraska should
end by early evening. Later tonight, additional thunderstorms
(second area) could form along a corridor from Sheridan county,
east southeast to Holt and Wheeler counties. Mid level warm air
advection will increase overnight across northern Nebraska. At the
same time, a weak shortwave will approach north central Nebraska
and southern South Dakota. This may lead to the development of
elevated storms tonight into Monday morning. Given the late night
timing, some gusty winds could occur INVOF thunderstorms, however,
the severe threat with this activity appears minimal. On Monday,
the frontal boundary will track to the northeast as a warm front
becoming oriented over the eastern portion of the forecast area.
The threat for thunderstorms will increase INOVF the boundary
Monday afternoon with the greatest threat east of highway 83.
Severe parameters appear more favorable for severe storms Monday
afternoon/evening. Deep layer shear is stronger Tuesday afternoon
in the northeastern forecast area and SB Capes of 3000-4000 J/KG
are forecast along a corridor from Eastern Custer county, north
northwest into Brown and northeastern Cherry county. Elevated CAPE
is also decent (1500-2500J/KG) Tuesday afternoon in the same
general area. That being said, the large hail threat seems more
favorable Monday night compared to this afternoon`s setup.

.LONG TERM...(Tuesday through Sunday)
Issued at 335 PM CDT Sun Jul 31 2022

Tuesday will be very hot with widespread 100`s forecast across
the area. A frontal boundary will approach the SD/NE border by
early Tuesday evening. In advance of this feature, deeply mixed
conditions are expected with southwesterly winds extending up to
above 600mb Tuesday afternoon. Forecast soundings spell this out
with unidirectional winds up to this level. Forecast dew points
are in the upper 40s to middle 50s Tuesday afternoon, and this
lends further support to readings in the lower 100s. For the
temperature forecast Tuesday, utilized the NBM guidance which was
in the 80+ percentile for highs. Given the synoptic setup south of
the approaching front Tuesday, the NBM forecast seems to be on
track. On Tuesday night, the frontal boundary will pass through
the area, bringing some relief from the heat and increased
precipitation chances across the area. After Tuesday night, mainly
dry conditions are expected through the end of the week. Ridging
will build back into the Rockies then Central Plains by late week
with temperatures rising back to near 100 Friday and Saturday. The
next threat for precipitation will arrive Saturday night into
Sunday as the ridge is suppressed by a northern stream wave and
surface FROPA.

&&

.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 531 PM CDT Sun Jul 31 2022

Small clusters of thunderstorms have developed across southwest
Nebraska. Expect storms will continue to develop and move into
south central Nebraska this evening. Current indications are that
storms will not affect airfields but will be close enough to KLBF
for VCTS for the first few hours. Will also have to watch for
outflow winds which may create gusty conditions and variable wind
directions well away from convection. Outside of storms, expect
VFR conditions through tonight. There is a signal in guidance for
some elevated showers/storms up near KVTN toward daybreak so will
use VCTS for a few hours then and reevaluate as new data becomes
available. Dry VFR conditions will be predominate Monday morning
with additional thunderstorms possible Monday afternoon.
Confidence in timing and location is not high enough at this point
to mention in TAFs but a mention may be added with later forecast
issuances.

Outside of thunderstorms and convective outflow, winds may be a
bit gusty but generally no significant impact to aircraft
operations from wind through this valid period.

&&

.LBF WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

SYNOPSIS...Buttler
SHORT TERM...Buttler
LONG TERM...Buttler
AVIATION...MBS



Area Forecast Discussion

National Weather Service Louisville KY

 1025 PM EDT Sun Jul 31 2022

.Forecast Update...
Issued at 1025 PM EDT Sun Jul 31 2022

...FLOOD WATCH REMAINS IN EFFECT OVERNIGHT...
...GUSTY SOUTHWEST WINDS EXPECTED MONDAY...
...STRONG TO SEVERE THUNDERSTORMS POSSIBLE MONDAY EVENING...

Evening satellite imagery shows partly to mostly cloudy skies across
the region.  Some partial clearing developed over southern Indiana
earlier, but low clouds are developing and most areas will see
mostly cloudy skies overnight.  Temperatures across the region this
evening were in the lower-mid 70s.  Expect readings to continue to
slowly drop with most locations dipping into the 69-72 degree range
for lows.

Radar returns this evening have been rather light across the region.
Current batch of showers is moving out of our CWA and into WFO JKL`s
area.  High resolution models suggest some additional activity
developing over central KY overnight.  Rainfall amounts from the
models are not overly impressive up toward the Parkways, therefore
have gone ahead and cut some of the western and northern portions of
the Flood Watch.  Will maintain the southeastern sections of our
forecast area in the Flood Watch, given that showers overnight will
have the potential to be fairly efficient and may be able to drop up
to an inch or so in spots, though some spots could pick up locally
higher amounts.  The reduction in the Flood Watch closely matches
the latest WPC excessive rainfall outlook nicely.  Given the
reduction in the Flood Watch area, have also lowered PoPs overnight
for areas along and north of the WK/BG Parkways.

Most of the shower activity overnight should be out of our forecast
area by dawn, Monday.  After that, some partial clearing is expected
with an increasing pressure gradient.  This will result in gusty
southwest winds of 10-15 mph with gusts of 25-30 mph being possible
at times.  The winds should pick up by mid-late morning and then
continue through the afternoon hours.

During the afternoon, we should see a decent amount of surface
heating ahead of an approaching cold front.  Model guidance shows an
increase of mid-level winds through the Ohio Valley and the latest
guidance shows about 25-30kts of bulk shear across the region.  A
rather unstable airmass is expected to develop across the region
with temperatures warming into the mid-upper 80s with dewpoints in
the upper 60s to the lower 70s.  This should result in MLCAPE values
above 3000 J/kg, with decent low-mid level lapse rates.  Preliminary
thinking here is that slab forcing along the frontal interface along
with the mid-level jetlet coming through should be enough to get
convection to fire across central IN and into central OH in the late
afternoon/evening.  This convection will then drop southward into
KY. Initial convection looks to be cellular, and given the wind
profiles, some supercellular structures can`t be ruled out.
Convection should then grow upscale into some sort of linear line
with time.  In the initial cellular mode, damaging winds and perhaps
some marginally severe hail would be the primary hazards.  Once
upscale growth into a line commences, damaging winds would be the
primary severe threat.

&&

.Short Term...(This evening through Monday)
Issued at 330 PM EDT Sun Jul 31 2022

...FLOOD WATCH CONTINUES FOR CENTRAL KENTUCKY UNTIL MONDAY
MORNING...

Synopsis...Latest satellite and regional radar imagery show the weak
surface boundary acquiring a more SW-NE orientation with the tallest
storm cores well into the Mid South associated with a mid-level PV
anomaly. Although one might argue that the boundary orientation will
not favor convective initiation along south-central Kentucky for the
next 12 hours, decided not to modify the Flood Watch on effect
through Monday morning pending increased confidence on latest
trends.
By Monday, southerly winds will advect a high theta-e airmass which
in combination with an approaching cold front will account for a
severe weather threat during the late afternoon and evening.
Damaging wind, small hail, and heavy rainfall are the primary
threats but a brief spin-up cannot be ruled out.

Tonight...Although there is plenty of low-level moisture, evident by
the overcast cloud layer and dewpoints, GOES-16 water vapor and
AMDAR sounding at SDF confirm dry air entrainment above 500 mb with
very stable lapse rates in the mid and upper levels. This explains
the lack of convection during the last couple of hours and probably
the trend going into the evening if the the PV anomaly moving
through the Mid South do not assist on trigering storms in south-
central Kentucky. Given the broad model consensus during the next 12
hours regarding QPF, decided not to modify the Flood Watch on effect
through Monday morning. If storms do develop, then skinny CAPE
profiles and slow Corfidi Upshear vectors will support isolated
instances of flash flood, especially across the Cumberland region
where FFG guidance is the lowest.

Monday and Monday evening...It will be another cloudy morning with
an stratus layer entrenched area-wide and possibly isolated showers
and/or storms to the south near the Tennessee border. A clearing
trend will start late morning into the early afternoon courtesy of
southwesterly wind that will gust between 20-25 mph at peak heating
time. Solar heating and warm advection will take the highs to the
upper 80 and low 90s with dewpoints well above the 70 degree-mark.
By the time the cold front approaches southern Indiana, the warm
sector will be characterized by a highly unstable environment (CAPE
around 4,000 j/kg), mid-level dry air which enhances convective
instability and DCAPE values around 1,400 j/kg, and effective deep
shear between 30-40 knots capable of producing organized convection.
Even though there is still some timing differences on the convection
arrival/initialization (between 01/21Z and 02/05Z), CAM guidance
trends indicate a cellular storm mode at the beginning (supercells
possible) with bowing segments preferred as convection moves
southward. STP values are above 1 with a decent amount of 1-km and 3-
km helicity, but factors such as LCL above 1,000 feet and modest mid-
level wind do not favor tornadogenesis.

.Long Term...(Monday night through Sunday)
Issued at 300 PM EDT Sun Jul 31 2022

Oppressive humidity this week...

An upper level trough is forecast to be positioned over the Ohio
Valley at the start of the forecast period at 12z Tuesday. This
feature quickly exits off to the east, with weak height rises
throughout the daytime. Could have some lingering convection
ongoing, especially near the Lake Cumberland region. However, this
activity will be weakening/exiting and should be followed by drier
conditions overall after sunrise. The weak "cold" front just north
of the Ohio River Tuesday morning will continue to weaken as it
washes out over the area. This will leave a very humid but weakly
forced environment Tuesday afternoon. Certainly cannot rule out
isolated to widely scattered pop-up showers and storms, but will
keep PoPs low. Suspect that many will remain dry during the second
half of Tuesday and into Tuesday night. This could change, if
perhaps a lingering mesoscale boundary could help spark scattered
convection Tuesday afternoon and evening. However, confidence is low
in mesoscale evolution.

The main story through the remainder of the week will be the heat
and humidity. While the heat will not be extreme, it will get rather
warm with oppressive humidity. Sfc dewpoints are forecast to remain
in the 70s Tuesday through the end of the week and will peak in the
mid/upper 70s at times. Heat index values will increase to around
100 as early as Tuesday afternoon near and west of I-65.

As we move into mid-week upper ridging will build over the Plains
and Southwest, keeping the bulk of the heat (afternoon temperatures
rising past the century mark) over the Plains. Still, we`ll see a
return to temperatures in the 90s. Right now, Wednesday looks like
the day with the most unpleasant combination of highest
heat/humidity and lowest chances of cooling thunderstorms. Afternoon
heat index values of 100-105 are likely.

A cold front may make a run at us Thursday or Friday, increasing the
chances of storms, though ensembles are not particularly
enthusiastic with rainfall amounts.

&&

.Aviation...(00Z TAF Issuance)
Issued at 724 PM EDT Sun Jul 31 2022

IMPACTS:
 - MVFR cigs overnight, possible drops to IFR late
 - Gusty SW Surface Winds Monday afternoon
 - Chance of strong/severe storms at KHNB/KSDF toward 02/00Z

DISCUSSION:

Currently, a wave of rain showers continues to push through central
Kentucky this evening.  This has been primarily affecting the KBWG
terminal with off and on showers.  This activity will continue to
push off to the east and move out of KBWG, but may scrape the KLEX
terminal by mid-evening.  KHNB/KSDF should remain mostly dry, though
we can`t rule out a stray shower at KSDF.  Cigs will start off
mainly VFR, but expect a drop to MVFR after dark.  Winds this
evening will remain light and variable and may end up becoming
mostly light out of the south overnight.  Further drops in ceilings
are possible late tonight.  There is a risk of IFR cigs toward dawn
Monday.  Given the guidance, the best chance of this occurring is
over at KLEX.  After sunrise, cigs should improve to VFR by mid-late
morning.  Southwest gusty winds will develop with sustained speeds
of 10-13kts and gusts of 20-24kts will be possible through the
afternoon.  A cold front will approach the region Monday evening
which may bring thunderstorms to KHNB/KSDF/KLEX after 31/23Z.

CONFIDENCE:

Confidence in the elements for this evening and overnight are
medium.  Confidence for Monday is generally medium-high.


&&

.LMK WATCHES/WARNINGS/ADVISORIES...
IN...None.
KY...Flood Watch until 8 AM EDT /7 AM CDT/ Monday for KYZ054>057-
     064>067-073>078-081-082.

&&

$$

Update.......MJ
Short Term...ALL
Long Term....EBW
Aviation.....MJ