Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 08/02/21
See below for an aviation forecast discussion for the 00Z TAFs.
&&
.SHORT TERM...(This Evening through Monday Night)
Issued at 312 PM CDT Sun Aug 1 2021
Satellite, surface obs, along with the hrrr smoke forecast show our
far eastern cwa being affected the most by surface smoke tonight.
Several obs have come down to 5 miles late this afternoon. The hrrr
surface smoke shows the smoke mainly affecting our far eastern cwa
tonight as it mixes/thins out on Monday. The vertically integrated
smoke and satellite also show smoke coming around the western upper
level ridge through Monday night. The hrrr surface smoke does show
little to no smoke on Monday across the cwa as it disperses.
Therefore, have adjusted the surface weather grids and sky cover
through the period. Otherwise, surface high pressure will build
south across the region tonight into Monday. The winds will be
mostly light and go from east northeast tonight to south into
Monday. Highs on Monday will be a few degrees warmer than today in
the 80s and lower 90s with lows tonight and Monday night ranging
from the mid 50s to the lower 60s. Also, tonight through Monday
night will be dry.
.LONG TERM...(Tuesday through Sunday)
Issued at 312 PM CDT Sun Aug 1 2021
An upper-level ridge will remain in place across the Rockies through
much of the work-week, leading to predominantly dry conditions and
above average temperatures across the forecast area (highs most
likely in the 90s along and west of the James River Valley by the
end of the week). A couple shortwaves from Friday through the
weekend will flatten the ridge, usher in deeper moisture from the
Gulf, and increase the chances for precipitation while maintaining
above-average temperatures. Models are already in decent agreement
about depicting a stronger shortwave through the Northern Plains by
the end of the period.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday Evening)
Issued at 638 PM CDT Sun Aug 1 2021
Terminals KABR,KATY,KPIR,KMBG
It appears there is a much better chance of seeing prevailing VFR
conditions throughout the TAF valid period at all four terminals.
The latest dispersion output supports some smoke (<3sm visby)
maybe getting into the KATY terminal later tonight/early Monday
morning for several hours.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...None.
MN...None.
&&
$$
UPDATE...Dorn
SHORT TERM...Mohr
LONG TERM...Lueck
AVIATION...Dorn
Area Forecast Discussion
National Weather Service La Crosse WI
948 PM CDT Sun Aug 1 2021
.SHORT TERM...(This evening through Monday)
Issued at 248 PM CDT Sun Aug 1 2021
We continue to see the elevated and near surface smoke/haze get
pushed out of the area with high pressure building in.
However, the reprieve from the smoke/haze may not last long
with GOES-16 satellite showing more spreading southward to the
international border. The HRRR seems to be handling trends well
and would support a return of the smoke on Monday, though likely
not as prolific and mostly remaining elevated with limited surface
impacts.
Otherwise, very pleasant/comfortable summer weather remains on
tap compliments of Canadian high pressure. Generally 50s for
lows with 40s possible in cold drainage areas, and 70s for highs
Monday.
There is a small chance for a few showers Monday afternoon, with
some glancing lift attendant to a passing shortwave to our east.
For now have confined these PoPs to our far north where model
soundings show a bit deeper mid level moisture and some weak
instability with SBCAPEs of 200-600 j/kg.
.LONG TERM...(Monday night through Sunday)
Issued at 248 PM CDT Sun Aug 1 2021
A few showers can`t be ruled out once again Tuesday afternoon,
especially in our far north/east service area with some signal
for a weak backdoor front nearby and glancing shortwave energy.
Overall though predominantly dry conditions into midweek with
heights aloft increasing atop a gradually retreating surface high.
A developing light southerly wind will foster temperatures
moderating closer to seasonal norms on Wednesday.
The latter half of next week into the weekend looks to turn more
unsettled/active as the flow aloft turns semi-zonal and strengthens.
A predominantly SSW low to mid level flow will usher in warmer
air with temperatures near to a bit above normal. Moisture will
also gradually increase, and lead to periodic shower and storm
chances with embedded shortwaves in the meridional flow.
&&
.AVIATION...(For the 06Z TAFS through 06Z Monday evening)
Issued at 946 PM CDT Sun Aug 1 2021
High pressure will provide mainly VFR conditions at the TAF sites.
The only concern overnight will be some valley fog and whether it
will affect KLSE or not. At this time, there is still a 12F spread
in the temperature and dew point, so just went with a BCFG toward
sunrise.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
IA...None.
&&
$$
SHORT TERM...McClure
LONG TERM...McClure
AVIATION...Boyne
Area Forecast Discussion
National Weather Service Denver/Boulder CO
905 PM MDT Sun Aug 1 2021
.UPDATE...
Issued at 829 PM MDT Sun Aug 1 2021
The forecast remains on track this evening with only a couple
showers in the mountains. The latest run of the HRRR smoke model
keeps smoke across the I-25 corridor and plains through tomorrow
so smoke will be kept in the forecast.
&&
.SHORT TERM...(This evening through Monday)
Issued at 250 PM MDT Sun Aug 1 2021
Current satellite and radar shows the bulk of convection staying
well to our west over western Colorado, under the deeper moisture
plume. We don`t see this plume shifting much through the evening,
as low levels are still drying slightly and only the upper levels
are attempting to moisten. We`ve trimmed back PoPs a little more
for the high country, but isolated to scattered convection is
still possible along/west of the Continental Divide. Temperatures
will be relatively cool and slightly below normal for tonight.
On Monday, we do see the deep monsoonal moisture plume shifting
ever so slightly and slowly eastward. This should result in an
uptick of convective coverage and intensity across our mountain
areas, and with that, an increased risk of flash flooding to burn
scars mainly west of the Front Range. The deeper moisture is
expected to arrive slowly given the amplitude of the ridge and
slow advection of monsoonal moisture ahead of the upper level
disturbance moving across the Great Basin. However, by late in the
afternoon and evening we should start to see a few storms work
east down the Front Range. Most of those may end up being outflow
dominated and weakening, reducing the threat of heavy rainfall.
Most of the plains east of I-25 should stay dry through the
afternoon. Temperatures will continue to warm, with mid to upper
80s for highs across the plains.
.LONG TERM...(Monday night through Sunday)
Issued at 212 PM MDT Sun Aug 1 2021
We should see at least a few showers continue through the early
overnight hours tomorrow night as our moisture plume slowly drifts
to the east. Instability should decrease fairly quickly after
sunset as we lose daytime heating, but there could be a continued
heavy rain threat through the evening. After midnight, most of our
activity will die off, but our specific humidities are likely to
moisten.
Tuesday is shaping up to be a bit wetter than Monday, with better
moisture across most of our CWA. Model soundings over the high
country show more than adequate instability in addition to PWATs
approaching an inch. Forecast guidance is still somewhat
inconsistent with the overall setup, with the GFS and GEFS are a
bit drier/stable over the high terrain while the Euro ensemble
suggesting high probabilities of surface CAPE > 500 J/kg. Have
opted towards the Euro and wetter solutions for now, but
confidence in the overall setup is still relatively low. However,
if guidance continues to advertise a good parameter space for
heavy rain, and additional Flash Flood Watches could be needed for
the high terrain. Stay tuned.
Tuesday night into Wednesday could see some activity drift off
into the plains as moisture continues to slide to the south and
east. Have increased PoPs a little over the plains compared to NBM
but overall precip potential is fairly low. Model soundings show
at least a weak cap Tuesday evening, but we could transition to a
light rainfall event into Wednesday morning if the Euro solution
is reasonable. Will have to watch trends there as recent runs have
been more optimistic at getting measurable precip into the metro.
Beyond Wednesday, the pattern quiets down a little bit with most
of our moisture shunted out of the region. Warmer and drier
weather looks likely Thursday and Friday, with temperatures
warming back into the 90s. Another monsoon push of moisture is
possible by next weekend, but for now will maintain just chances
of afternoon storms across the high country.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 829 PM MDT Sun Aug 1 2021
ILS landing conditions should persist for another hour or two with
visibility improving slightly as the evening progresses. By
daybreak, visibilities will decrease again so ILS landings can be
expected. We don`t expected any thunderstorms through most of
Monday, as we`ll be too stable. There`s just a slight chance of a
storm toward 00Z Tuesday.
&&
.HYDROLOGY...
Issued at 250 PM MDT Sun Aug 1 2021
It appears most of the convection through this evening will stay
west of the burn areas. There is just a limited threat for flash
flooding west of the Continental Divide (East Troublesome and
Williams Fork burn areas). There is still a relatively high
amount of moisture there so if a storm can develop, a quick one
half inch of rain is possible.
Deeper moisture gradually returns to the forecast area Monday,
although the best arrives late in the afternoon or evening hours.
Right now, it still looks like areas along and west of the Front
Range will have the main threat of heavier rainfall. Precipitable
water and 700-500 mb specific humidity should be sufficient for
decent precipitation efficiency, and rainfall rates up to 1 inch
in 40 minutes. However, we are uncertain regarding destabilization
and the exact timing of arrival of the better moisture as the
upper level disturbance over the Great Basin will be slow to move
into the upper level ridge axis. We`ve issued a Flash Flood Watch
for the burn areas mainly along and west of the Front Range,
although it`s not impossible the threat could shift into the lower
elevations of the Cameron Peak burn toward late afternoon or
evening. The Watch could be expanded later if moisture arrives
faster than currently expected.
Flash flooding concerns will continue on Tuesday. The moisture
plume should be over our forecast area, with PWATs near 150% of
normal with very weak steering flow. It looks like there`s a
little bit more forcing over the region during the afternoon, and
thus there should be more widespread coverage across the high
country during the day. With instability increasing yet again, in
combination with the aforementioned weak steering flow, slow
moving thunderstorms would be likely. We`re still far enough out
that this could change, but it is certainly possible that another
Flash Flood Watch could be needed for the high terrain. Some of
the rainfall could drift into the I-25 corridor, but there is less
confidence in that happening.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
Flash Flood Watch from Monday afternoon through Monday evening
for COZ032>034.
&&
$$
UPDATE...Danielson
SHORT TERM...Barjenbruch
LONG TERM...Hiris
AVIATION...Danielson
HYDROLOGY...Barjenbruch/Hiris
Area Forecast Discussion
National Weather Service Charleston SC
1023 PM EDT Sun Aug 1 2021
.SYNOPSIS...
A stationary front will maintained unsettled weather including
the chance for heavy rainfall across the area through the
upcoming week.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
It`s taken awhile, but convection has finally arrived along a
southward progressing outflow boundary and the collision of the
earlier sea breeze and some activity moving in from the west.
With forcing from a short wave aloft, the HRRR and the HREF
indicate clusters or a broken band of showers and thunderstorms
will impact mainly the Charleston quad-county region through 1
or 2 AM, before pulling offshore. We will show 40-50% chances
this areas where the higher MLCAPE of 1500 to 2000 J/kg exists.
PoPs elsewhere will be held to 20-0% where instability is less.
DCAPE as high as 1000-1200 J/kg will still support the
possibility of strong or perhaps marginally severe winds over
the 4 counties surrounding Charleston County. We maintained
mention of this in the Hazardous Weather Outlook.
Temps in many places are running a bit lower than this time
last night. Since dew points are also lower than 24 hours ago,
min temps tonight are forecast a tad lower than last night. We
are expecting mid or upper 70s across the entire region. The
exceptions might be coastal Charleston and coastal Colleton if
convection fades before there.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/...
This period will feature a change to cooler temperatures and a wet
pattern including the potential for heavy rainfall and flooding.
Monday: A surface cold front will stall over or just north of the
region, while an upper level trough will amplify over the eastern
CONUS. Guidance indicates that best moisture featuring PWAT values
around 2 inches should be temporarily pushed into southern counties.
Given this scenario, isolated/scattered showers and thunderstorms
should hold off until afternoon across northern/inland counties.
Across the south, showers/thunderstorms will develop earlier, and by
mid to late afternoon expanding coverage justifies at least likely
PoPs.
MLCape values as high as 2500-3500 j/kg could support a localized
threat for brief/damaging wind gusts across southern counties Monday
afternoon.
Otherwise, Monday will spend the end to the recent excessive heat
regime. Across southern counties, heat index values could top out in
the 100-105F, while maximum heat index values 95-100F will be common
elsewhere. Give these expectations, additional Heat Advisories are
not expected.
Monday night: We will transition to more widespread
showers/thunderstorms and an increasing threat for locally excessive
rainfall/flooding.
A unusual baroclinic regime will develop in the vicinity of the
quasi-stationary front. Also, as the anomalous eastern CONUS
longwave trough amplifies, a shortwave trough will eject NE across
the region. Meanwhile, low-mid level moisture transport will
intensify and will push a plume of PWAT values 2.2-2.3 inches across
the forecast area. categorical PoPs offered by guidance appear
reasonable, and repeating periods of heavy rainfall could produce
localized flooding. Sunday 12z HREF guidance depicts non-zero
probabilities of 12 hour precipitation exceeding 5 inches across a
wide swath of the forecast area, including pockets of 20-60 percent
probs near the coast.
Tuesday through Wednesday: A persistent pattern with an anomalously
deep eastern CONUS upper trough, shortwave troughs/associated
forcing for ascent ejecting from this feature across our area, an
unseasonably strong, active baroclinic zone, deep-layered moisture
advection within the plume of PWAT values mainly exceeding 2 inches
will combine to support episodes of widespread showers/thunderstorms
and a threat for locally excessive rainfall/flooding. Latest
forecasts include mainly categorical PoPs through this period, but
in reality periods with widespread precipitation could be punctuated
by periods of lesser coverage. This type of regime raises
uncertainty regarding specific timing, coverage/location and
rates/amounts of heavy rainfall. In general, over time total
rainfall accumulations should increase in amount and coverage, and
this will in turn raise the probability for significant flooding
during subsequent episodes of heavy rain.
Otherwise, expect below-normal temperatures through midweek.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
The overall complex and unusual scenario at the surface and aloft
which sets up through midweek will persist through late week and
perhaps even into next weekend. Overall, above-normal precipitation,
the potential for locally heavy rainfall and flooding, and below
normal temperatures will continue. While the greatest coverage and
intensity of precipitation seems most likely during times of maximum
heating during each afternoon/evening, precise timing and impact of
heavy rain events remains elusive. In general, the overall threat
for flooding should increase with time due to the persistence of
this unseasonable scenario.
&&
.AVIATION /02Z MONDAY THROUGH FRIDAY/...
There continues to be indications that the convection upstream
will develop into a broken band of SHRA/TSRA, and impacting the
KCHS and KJZI terminals from about 03-06Z. This is also
somewhat consistent with the previous forecast. Convection near
KSAV looks to stay too isolated in coverage to show anything
more than VCTS from 04-06Z. Direct impacts on any terminal,
especially KCHS and KJZI will result in flight restrictions and
potentially gusty winds.
Monday morning and early afternoon will essentially be void of
convection, before coverage increases during the mid afternoon
and beyond. This occurs in response to a nearby cold front and
an approaching upper trough. However, since any SHRA/TSRA will
occur so late in the latest 00Z TAF period, we have opted not to
include at this time. Be assured that any direct impacts though
will cause flight restrictions. Latest TAF issuances will fine
tune the situation.
Extended Aviation Outlook: Periods of flight restrictions are
certain this week, especially in showers/thunderstorms.
&&
.MARINE...
Overnight: Southwest winds across the SC waters will continue
to gusts to around 25 kts through 1-2 AM, resulting in a
continuation of the ongoing Small Craft Advisories for AMZ350
and AMZ352.
A band of strong thunderstorms will push off the coast and
impact mainly the South Carolina Atlantic waters and Charleston
Harbor from 12 AM to 2 or 3 AM. Special Marine Warnings could be
required for winds in excess of 34 kt.
In the wake of the thunderstorms, winds are expected to shift
from the WSW, with speeds of 15 kt gusting to 20 kts. Seas are
expected to range between 2-4 ft.
Expect hazardous marine conditions within/near thunderstorms through
this week. Outside thunderstorms, southwest winds could average 15-
20 knots at times, and seas should average 2-4 feet, perhaps as high
as 5 feet beyond 20 nm, through late week. Occasional Small Craft
Advisory gusts cannot be ruled out.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
MARINE...Small Craft Advisory until 2 AM EDT Monday for AMZ350-352.
&&
$$
NEAR TERM...
SHORT TERM...SPR
LONG TERM...SPR
AVIATION...
MARINE...
Area Forecast Discussion
National Weather Service Des Moines IA
635 PM CDT Sun Aug 1 2021
.SHORT TERM.../Tonight through Monday Night/
Issued at 229 PM CDT Sun Aug 1 2021
Confidence: High
High amplitude flow continues to intensify over the upper Great
Lakes early today with large gyre over eastern Canada bringing
nearly due north winds into Iowa and the Great Lakes states. A weak
cool front at 12z bisects Iowa from northwest to southeast while
another weaker boundary is located over northern MN/WI vicinity.
Aloft the Iowa boundary`s H850 reflection is easily seen on subjective
hand analysis. The main area of moisture aloft is currently south
of a frontal boundary that stretches from New York State through
the lower Ohio River Valley southwest into the Texas Panhandle
northwest toward the Pacific Northwest. South of the boundary H850
dewpoints are in the 10 to 15C range with the highest moisture
confined to the southeast for the time being. An expansive ridge
of high pressure continues over the western states where H850
temperatures are now in a range of 15 to 25C while the cooler
intrusion of air into Iowa and the Great Lakes now ranges from 10
to 14C this morning. Iowa continues to see forest fire smoke
drifting south southwest this morning and covering most of the
state north into Minnesota. Air quality concerns have returned for
much of the region through Monday.
Tonight will remain quiet with a continuation of northerly flow.
Despite the smoky skies present, with the cooler H850 airmass
intruding south now, our overnight lows will drop to into the
lower 50s northwest to the upper 50s south. Though about 7 degrees
cooler than normals, we will still be shy of any records by about
another 7 degrees tonight. The expansive area of cooler high
pressure will drop southeast tonight into Monday and keep the
region quiet with light winds and very pleasant temperatures.
Similar to today, highs Monday will only reach the upper 70s to
around 80 as some smoke remains across the region. Little change
is expected Monday night as the high pulls east and H850 temperatures
begin to recover slowly into Tuesday morning. Lows will be similar
to tonight, but a degree or so warmer for most locations.
.LONG TERM.../Tuesday through Sunday/
Issued at 229 PM CDT Sun Aug 1 2021
Confidence: Medium to High
Overall, the extended forecast remains generally quiet through at
least Wednesday. Tuesday the high will continue to edge east into
the Ohio River Valley while a weak trough begins to take shape over
the Northern Plains. In response to the increasing warm air advection,
a warm front is anticipated to form from western Minnesota to
northeast Wisconsin. Increasing instability may lead to some
clouds and showers and thunderstorms; mainly over MN and Wisconsin
with some mid-level clouds over the north/northeast Tuesday afternoon.
Otherwise, highs Tuesday will begin to warm faster northwest as
H850 temperatures increase over the area and reach the mid-upper
teens northwest by Tuesday. By late Wednesday, the trough/low over
the Northern Plains will begin to drift southeast across MN as
the low tracks northeast into Canada. Temperatures will again be
warmer northwest with afternoon highs in the mid 80s and another
dry day can be expected. The weak boundary is expected to drift
southeast Thursday and interact with a weak wave. This should
bring a chance of showers and thunderstorms across Iowa during the
day. Highs Thursday will change little from Wednesday. By the end
of the week into the weekend, energy currently off the coast of
British Columbia will shed a short wave east into the Northern
Plains. With increasing westerlies aloft, our temperatures will
begin to see a bump up as hotter air west begins to migrate east
with time. H850 temperatures Friday should be in the upper teens
with readings on Saturday 21-24C by days end. While the GFS forecasts
H850 temperatures nearing 23-26C by 00z Sunday and crashes temperatures
into Sunday with a cold front that may not have enough upper level
support to dive south through Iowa; the more modest and consistent
Euro is tracking at 22-25C through 00z Sunday and remains about
the same on Sunday. Deferring to the more consistent Euro suggests
that highs Saturday should reach the lower 90s with highs on
Sunday the lower to mid 90s west. Both medium range models suggest
a wave and push of thetae advection overnight Sat night into
Sunday morning, resulting in chances for storms. Though instability
parameters are sufficient for some stronger storms, at this time
the better forcing and bulk shear is forecast into Minnesota/Wisconsin
and mainly northeast of our area, though we have included some
chance PoP northeast. Though the GFS again appears too fast again
next weekend, both medium range models suggest a front near the
region early into the following week and a potential for more
storms.
&&
.AVIATION.../For the 00Z TAFS through 00Z Monday evening/
Issued at 632 PM CDT Sun Aug 1 2021
Confidence in VFR conditions has increased with much of the near
surface smoke affecting visibilities now south and west of TAF
sites and expected to remain so through the period based on HRRR
smoke trends. Although there may be some VFR smoke aloft central
and west through midday Monday, mainly expect nothing more than
few-sct high based diurnal cumulus with light and variable winds.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...REV
LONG TERM...REV
AVIATION...Small
AREA FORECAST DISCUSSION
National Weather Service Sioux Falls SD
1038 PM CDT Sun Aug 1 2021
.SHORT TERM...(This Evening through Monday)
Issued at 234 PM CDT Sun Aug 1 2021
The primary concern in the short term is smoke and air quality
across the area.
A ridge of high pressure will move over the area overnight and
then slowly move to the east through the day on Monday. HRRR Smoke
model shows near surface smoke moving into southwestern Minnesota
later this evening and then slowly spreading west overnight. In
addition, the nocturnal inversion may also allow smoke to
concentrate near the surface overnight producing unhealthy air
quality - especially along and east of I-29. Wind will remain
light on Monday although strong summer sun should allow for a
deepening boundary layer which is expected to improve air quality
to some extent through the late morning and afternoon.
No precipitation is expected through Monday. Clear skies and
light winds will allow for good radiational cooling tonight. Lows
overnight will be in the 50s. Highs on Monday will be in the 80s.
.LONG TERM...(Monday Night through Sunday)
Issued at 234 PM CDT Sun Aug 1 2021
For the long-term a warming trend is expected through the week and
into next weekend.
Dry weather is expected through Tuesday night across the area as
northwest flow aloft continues. As the ridge moves to the east,
southerly flow will increase aloft first and reach the surface
during the day on Tuesday. There is uncertainty if smoke will
again be an issue Monday night into Tuesday morning before
southerly winds increase. On the one hand a strong nocturnal
inversion will again develop helping to concentrate any smoke near
the surface. However, with light winds, there should be less
smoke advecting southward. And mixing Monday afternoon will help
to remove some smoke from the boundary. At this time did not
include smoke in the forecast for Monday night or Tuesday but for
those who are negatively impacted by smoke, check later forecasts
to see how air quality will evolve. Otherwise, mostly clear or
sunny skies are expected. With strengthening southwest winds above
the surface, there may be stronger winds northeast of the Buffalo
Ridge late Monday night which will help keep temperatures in the
lower 60s. Otherwise, lows will range from the mid 50s in northwest
Iowa to around 60 in south central South Dakota. On Tuesday,
highs will range from the mid 80s east of I-29 to around 90 west
of the James River.
An upper level wave will approach the region on Wednesday. A
surface trough is expected to extend across central South Dakota.
While winds will turn southerly ahead of the wave, moisture is
very limited with dew points likely to still be in the 50s by late
afternoon. 700-500 mb lapse rates are also only 5.5-6.5 C/km so
instability is also limited. This results in MLCAPEs less than
1000 J/kg. However, it is saturated above 700 mb so the question
will be if the forcing for ascent will last long enough for the
lower atmosphere to become saturated and rain to reach the ground.
There is a stronger signal from ensemble forecasts for rain
Wednesday into Wednesday night. While guidance PoPs remain around
20 percent, confidence is slowly growing for at least scattered
showers Wednesday afternoon and night.
A low amplitude ridge builds in the area for the end of the week
and the weekend. There remains uncertainty on the timing and
location of a leading wave moving into the area Saturday. Some
ensemble members keep this wave closer to the Rockies while others
take the energy closer to the Canadian border and few bring this
wave across South Dakota. With persistent southerly flow moisture
will be increasing but so will mid level temperatures with 700 mb
temperature above the 90th percentile in the ECMWF ensemble and
mean GFS 700 mb temperature greater than 12 C. This may result in
a strong enough cap to limit or even completely suppress any
convection this weekend. If convection does not develop through
Sunday it could be hot this weekend. The potential exists that
some places west of I-29 could rise above 100 degrees with most
other areas in the mid to upper 90s. Should convection develop,
then various outflows and clouds may "cool" temperature closer to
90 for highs. Bottom line is that any precipitation remains very
uncertain through the next 7 days and another round of heat is
likely by later this week.
&&
.AVIATION...(For the 06Z TAFS through 06Z Monday night)
Issued at 1036 PM CDT Sun Aug 1 2021
Overnight, expect near surface smoke to reduce vsby down to MVFR
along and east of the Interstate 29 corridor, including near FSD
and SUX, as sfc high pressure builds through. Further west,
should see mainly VFR conditions with weaker southerly flow and patchy
smoke possible. Expect vsby improve some at the sfc through the
morning as mixing increases winds but will still see smoke stream
through aloft through the day.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...Schumacher
LONG TERM...Schumacher
AVIATION...BP
AREA FORECAST DISCUSSION
National Weather Service Hastings NE
646 PM CDT Sun Aug 1 2021
...AVIATION UPDATE...
.DISCUSSION...(This evening through Sunday)
Issued at 250 PM CDT Sun Aug 1 2021
Forecast concerns include smoke/haze at least in the near term, and
then warming temperatures for the weekend.
Overall deterministic and ensemble models are in decent agreement
with the upper pattern for the next week. Will lean more on a blend
of deterministic models until the weekend, and then use a blend of
ensembles as deterministic models show more divergence in solutions.
HRRR smoke runs indicate that we could have a minor increase in
smoke coming tonight, but overall this should back off for Monday,
but smoke particulates will be stubbornly present to include haze
for the forecast heading into Monday/Monday evening. Until we can
get a shift of upper flow away from the north or northwest, this
could become a recurring feature for the next several days, unless
fires substantially quell.
Upper pattern reveals a ridge over the intermountain west that is de-
amplifying over time as a number of waves over the northern tier
help break it down. At the surface, a surface ridge will cross the
central Plains tonight with return flow ensuing for the week. This
will allow temperatures and dew points to slowly increase over time,
although slowly since the affects of the upper ridge are diminishing
over our area. By late in the work week, a trough will clear the
Plains and allow a temporary ridging to occur that will stem from
the subtropical ridge behind the shortwave trough and should help
boost temperatures into the 90s for highs. We have already been
trending warmer for the weekend and this seems like a prudent
direction. Although the forecast is mostly dry, there is a non-zero
chance of rain Wednesday night as a shortwave trough is still
forecast by deterministic models to come through the area within
north flow and there is potential for enough deep layer moisture to
at least produce isolated rainfall, especially north of the tri-
cities. This will need to be monitored for trends in future
numerical model runs. Kept trend of combining NBM and CONSALL for
highs on the weekend to help boost temps up a couple degrees into
the mid 90s.
&&
.AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Tuesday)
Issued at 645 PM CDT Sun Aug 1 2021
Significant weather: Minor visibility reductions due to smoke.
Tonight: Main issue will be continued haze from ongoing smoke.
VSBYs across the local area and upstream are better than 24hrs
ago, so think we`ll be primarily high end MVFR or VFR. Little to
no cld cover expected. NE wind will go lgt and vrbl around sunset.
Confidence: High.
Monday: Latest HRRR smoke runs suggest even more incremental
improvement to at least near-sfc smoke concentrations, so have
primarily VFR VSBYs for the daytime hrs. Will continue mention of
haze, though as smoke unlikely to completely vanish. Again,
little to no cloud cover. Lgt and vrbl winds in the morning will
become S-SE by midday, but only around 5-7kt. Confidence: High.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
DISCUSSION...Heinlein
AVIATION...Thies
Area Forecast Discussion
National Weather Service Green Bay WI
701 PM CDT Sun Aug 1 2021
Updated aviation portion for 00Z TAF issuance
.SHORT TERM...Tonight and Monday
Issued at 257 PM CDT Sun Aug 1 2021
The main forecast issue focuses on Monday and whether any showers
or thunderstorms can develop in a weakly unstable, weakly forced
environment.
The 19Z MSAS surface analysis showed a weak area of low pressure
over the eastern Great Lakes, a cold front stretched out from the
OH Valley to the central Plains and high pressure sinking south
into northern sections of ND. Visible satellite imagery indicated
plenty of cumulus clouds across the Great Lakes with thicker
clouds over the MN Arrowhead/northern WI/western Upper MI. Radar
had picked up on a few sprinkles over Upper MI at times, but not
overly impressive returns.
Any lingering cumulus clouds will dissipate early this evening as
daytime heating wanes and drier air from the high pressure settles
over the region. The high pressure will reside over the Midwest/
western Great Lakes tonight with mostly clear skies for most of
the night. A weak surface trough and weak mid-level shortwave
trough are forecast to swing into the northern Great Lakes toward
daybreak and may bring some increase in clouds into northern WI.
Min temperatures to range from the middle 40s to around 50 degrees
north, to the middle 50s east-central WI.
This high pressure settles into southern sections of the Great
Lakes region on Monday, allowing winds to become west-southwest
and bring a slight uptick in WAA. Meanwhile, the surface trough
continues to track east across the northern Great Lakes and the
shortwave trough digs into the middle of the Great Lakes.
Instability is weak (SBCAPES < 500 J/KG), shear is weak (20-25
kts), and lift is negligible. There may be just enough forcing to
squeeze out a few showers in the afternoon, but the vast majority
of the forecast area should be dry on Monday. Max temperatures for
Monday to mainly be in the middle to upper 70s.
.LONG TERM...Monday Night Through Sunday
Issued at 257 PM CDT Sun Aug 1 2021
Fairly quiet weather expected through at least mid week, then
increasing humidity and unsettled weather toward the end of the week
into the weekend.
Monday night: A dry surface ridge is will shift slowly southeast of
the area through this time period, bringing little to no
precipitation. The one exception could be early Monday evening as a
shortwave shifts to the southeast of the area. Instability is
expected to be around 500 J/kg through early evening; however, the
instability will quickly diminish toward sunset. Not expecting
anything severe, but an isolated thunderstorm may linger into the
early evening hours. Otherwise, temperatures are expected to be near
normal. Overnight lows will be in the upper 40s.
Tuesday through Wednesday: Models are hinting at a surface boundary
sinking southward into the area Tuesday into Tuesday night (although
with differing timing/placement), which may lead to some afternoon
showers and thunderstorms. This would mainly be during peak heating
into the early evening hours before diminishing after sunset. In
fact, models are painting out around 1000-1500 J/kg of MUCAPE, but
shear values are only around 15-20 kts. This would allow for strong
storms, but a relatively low threat of severe from pulse-type
storms. Behind the front, drier air is expected to arrive, bringing
fairly quiet conditions for Wednesday. High temperatures will warm
into the low to mid 80s with overnight lows in the 50s.
Rest of the extended: Model solutions differ on exact timing and
placement of features beyond Wednesday; however, there is some
agreement that a shortwave will pass through the area Thursday
afternoon into Thursday night and yet another larger scale system
approaching the area toward next weekend(Saturday. Instability will
steadily increase through this time period as dewpoints and
temperatures increase across the area. This will lead to a more
unsettled/active pattern for northeast Wisconsin with increasing
chances for showers and thunderstorms. Severe weather may be
possible from time to time, but it is too early to pin down the
details.
&&
.AVIATION...for 00Z TAF Issuance
Issued at 658 PM CDT Sun Aug 1 2021
Generally quiet weather with mainly VFR conditions is expected
throughout the TAF period. HRRR smoke guidance suggests minimal
impact at the surface tonight into mid-day Monday, with perhaps
some vsby restriction across the north returning tomorrow
afternoon. Convective cloudiness is likely to develop during the
late morning tomorrow, but bases should be abv 3K ft.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....Kallas
LONG TERM......Cooley
AVIATION.......Skowronski
Area Forecast Discussion
National Weather Service Grand Rapids MI
724 PM EDT Sun Aug 1 2021
LATEST UPDATE...
Aviation
.SYNOPSIS...
Issued at 258 PM EDT Sun Aug 1 2021
- Quiet Weather this Week
&&
.DISCUSSION...(This evening through next Sunday)
Issued at 258 PM EDT Sun Aug 1 2021
Upper troughing will bring several days of cooler than normal
temperatures before temperatures warm up by next weekend as
heights begin to rise. Only slight chance of showers on Tuesday
across the northeast zones as a shortwave trough moves through
with little moisture to work with.
Warm advection pattern and return flow moisture results in
increasing chances of showers and thunderstorms by the weekend.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 724 PM EDT Sun Aug 1 2021
The scattered showers that have been around late this afternoon
into early this evening are dissipating and should be totally gone
by 02z. Based on the the HRRR Smoke model I have added FU (smoke)
to most of the TAF forecasts during the sunrise hours of Monday.
There may be some light fog at that time too. Winds will become
light by midnight.
On Monday another shortwave comes through the area from the
north. This will result in the risk of isolated showers during the
afternoon. I did not put this in the TAF forecasts as the risk is
rather low and even if it happened, likely it would have little
impact on the Cigs/Vis. Winds will be northwest 5 to 10 knots
during the day light hours.
&&
.MARINE...
Issued at 258 PM EDT Sun Aug 1 2021
No changes to the forecast with winds and waves expected to
decrease overnight followed by several days of relatively light
winds and waves and good boating/swimming conditions.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...Beach Hazards Statement until 5 AM EDT Monday for MIZ037-043-050-
056-064-071.
LM...Small Craft Advisory until 5 AM EDT Monday for LMZ844>849.
&&
$$
SYNOPSIS...Ostuno
DISCUSSION...Ostuno
AVIATION...WDM
MARINE...Ostuno
Area Forecast Discussion
National Weather Service Wichita KS
645 PM CDT Sun Aug 1 2021
.SHORT TERM...(This evening through Wednesday night)
Issued at 153 PM CDT Sun Aug 1 2021
BOTTOM LINE UP FRONT: Below normal temperatures and mostly dry
conditions are expected to start the work week, and will be
accompanied by areas of smoke/haze. Temperatures and humidity will
then gradually increase from mid-week on. Thunderstorms are possible
WED/THU and again towards the weekend.
DISCUSSION
Latest surface analysis, early this afternoon, reveals a frontal
boundary continuing to sag south through the Southern Plains,
putting the Central Plains in a more stable, drier, northerly flow.
That said, lingering low to mid-level moisture and instability
may still allow a few diurnally-driven showers/storms this
afternoon near the KS/OK border ahead of a secondary push of
drier/more stable air. The more substantial push of drier/more
stable air will settle in over the next couple of days, and
should keep a lid on convection through at least Tuesday. With
northerly mid/upper flow continuing through mid- week, smoke will
continue to advect into the region from fires in Canada. HRRR
smoke guidance suggests this smoke layer may tend to become more
elevated by Monday, leading to hazy looking skies, but with
visibility and air quality not quite as bad as the next 12 hours.
Of note, most observation sites across the Central Plains are
showing reduced visibility due to the smoke, so it`s an
impressively widespread area of smoke our region is dealing with,
and may not mix out/become elevated as fast. Adding to the reduced
visibility will be the potential for shallow low-level
moisture/small T/Td depressions that may lead to some shallow fog
each morning.
By mid-week, a s/w is forecast to move out of the Central Rockies
and into the Central Plains as WRN U.S. ridging breaks down some. If
sufficient moistening occurs ahead of this wave, we could be looking
at a risk for isolated to scattered convection. However, from a
probabilistic standpoint, the majority of ensemble members from the
GFS/EC/CMC are dry, which gives lower confidence in seeing a
meaningful risk of precip locally. We`ll continue to see how this
wave trends in future model runs, though. If it comes out a bit
deeper, there could be a better return of moisture and an increased
risk of precip.
Temps through mid-week will be noticeably lower than what we have
seen over the past week, possibly kept even lower due to elevated
smoke. A gradual moderation is expected by mid-week, but at this
time it appears unlikely that we will see a significant rise in
temps or humidity.
Martin
.LONG TERM...(Thursday through Sunday)
Issued at 153 PM CDT Sun Aug 1 2021
In the wake of the mid-week wave, upper level ridging may briefly
build in Thursday before getting flattened by the end of the week.
Ultimately this should set up more of a zonal flow across the
Central Plains through next weekend. Increasing southerly low-mid
level flow combined with some modest downsloping should lead to a
more substantial warmup once again across the area. The southerly
flow will help bring increasing moisture/humidity as well.
Warming low- mid level temps should keep a pretty strong cap in
place during the day, keeping the risk of storms low. Towards the
weekend, some model guidance suggest a frontal boundary may
attempt to move through the area with at least a modest increase
in the risk of storms. If guidance is too quick to move that
boundary through, though, then we`ll probably be looking at a
continued period of dry conditions.
Martin
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 633 PM CDT Sun Aug 1 2021
For the most part no significant weather is expected through this
TAF period. Unfortunately, smoke from the fires along the west
coast will be moving into the region during the evening and
overnight. The atmospheric set up is such that much of this smoke
is expected to reach the ground and obscure some of the
visibilities toward 12Z and into the later half of the TAF. KCNU
is the most likely terminal to have issues and could see near IFR
visibility during after 17Z. KICT and KSLN may also have some
intermittent MVFR visibilities after 12Z. KHUT is expected to be
on the western fringe of the smoke this TAF period with KRSL and
KGBD likely to remain clear.
Metzger
&&
.PRELIMINARY POINT TEMPS/POPS...
Wichita-KICT 62 86 62 87 / 0 0 0 0
Hutchinson 59 88 61 88 / 0 0 0 0
Newton 60 85 61 86 / 0 0 0 0
ElDorado 60 84 60 84 / 0 0 0 0
Winfield-KWLD 61 85 61 86 / 0 0 0 0
Russell 59 89 61 91 / 0 0 0 0
Great Bend 59 88 60 89 / 0 0 0 0
Salina 59 88 61 90 / 0 0 0 0
McPherson 59 87 61 88 / 0 0 0 0
Coffeyville 63 84 61 85 / 0 0 0 0
Chanute 61 83 60 83 / 0 0 0 0
Iola 61 83 60 82 / 0 0 0 0
Parsons-KPPF 62 84 60 84 / 0 0 0 0
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SHORT TERM...RM
LONG TERM...RM
AVIATION...ELM
Area Forecast Discussion
National Weather Service Indianapolis IN
1148 PM EDT Sun Aug 1 2021
...Updated Aviation Discussion...
.Forecast Update...
Issued at 959 PM EDT Sun Aug 1 2021
Temperatures are in the 60s with dewpoints in the upper 40s to lower
60s and northerly winds around 4 to 12 mph. High pressure is
building in from the northwest and satellite loop shows clear skies.
Forecast is generally on track and no significant adjustments made,
although have less confidence in the development of patchy fog with
the pressure gradient across the area not relaxing as much as
earlier thought, and as a result winds may not go near calm.
&&
.Short Term...(This evening through Monday night)
Issued at 141 PM EDT Sun Aug 1 2021
Tonight.
Any showers associated with the passing frontal system will come to
an end by later this evening. With the frontal passage, expect that
surface smoke/haze that has been in place will clear which matches
up closely with the HRRR smoke guidance. The diurnally driven
clouds associated with the front will also exit which will leave
behind mostly clear skies and allow for near record cold
temperatures tonight across the area as dry air continues to advect
into the area. Lows are expected to drop into the mid to upper 50s
for much of the area due to the combination of the clearing skies
and a dry surface airmass that will optimize radiational cooling.
There also may be a few areas of fog towards the morning hours,
but with less surface moisture, not expecting as dense of
coverage as compared to this morning.
Monday and Monday night.
Another pleasant day is expected for tomorrow with partly skies and
highs in the upper 70s, especially as dew points remain in the upper
50s for much of the area. Northwesterly flow aloft is expected to
continue which may bring some lake enhanced cloud cover to the area
as slightly cooler air moves over the warmer lake water. The next
plume of smoke aloft will arrive tomorrow night, but don`t expect
quite the extent of surface impacts due to an expected inversion
just off the surface that will limit the intrusion of smoke into the
boundary layer.
&&
.Long Term...(Tuesday through Sunday)
Issued at 141 PM EDT Sun Aug 1 2021
An upper level trough will remain across the area for much of the
long term, before flow becomes less amplified late in the period.
During that time, an upper level low may develop.
Meanwhile, at the surface, high pressure will be the dominant
influence. An inverted surface trough will remain southeast of the
area.
With high pressure nearby, and surface northeast winds aiding in the
overall lack of moisture across the area, feel that chances for any
rain are too low to mention through at least Friday (even with an
upper low nearby at times).
For the weekend, moisture will return as the surface high will be
east of the area. This combined with warm temperatures could lead to
some diurnal convection by Sunday.
Temperatures will remain below normal into mid-week, then warmer air
will return. Highs near 90 are possible next Sunday.
&&
.Aviation...(06Z TAF Issuance)
Issued at 1148 PM EDT Sun Aug 1 2021
IMPACTS:
-Light northerly winds through the overnight.
-Some potential for patchy MVFR fog near daybreak at the outlying
sites.
DISCUSSION: Wind should be out of the north through the overnight
hours and much of Monday, with speeds around 3 to 6 kts overnight
and 5 to 10 kts from mid morning on. Patchy fog is possible near
daybreak, but will be dependent on how much mixing continues through
the night. Model trends look less impressive for fog, but not
confident enough to pull completely. Will keep tempo MVFR group to
cover the potential at the outlying sites. Could then see some few
to scattered VFR diurnal cu Monday afternoon.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Update...CP
Short Term...White
Long Term...50
Aviation...CP
AREA FORECAST DISCUSSION...CORRECTED
National Weather Service Jackson KY
918 PM EDT Sun Aug 1 2021
.UPDATE...
Issued at 918 PM EDT SUN AUG 1 2021
At 1z, a line of struggling cumulus towers with embedded mainly
sprinkles/light showers was located was located near an Irvine to
Jackson to Prestonsburg line. The western flank of the line over
Powell County appears to a bit more organized, courtesy slightly
better instability and low-level convergence. Current HRRR trends
suggest that this will continue to be the case with the better
shower activity generally riding SSE along/just east of the
Pottsville Escarpment to near the Hal Rogers Parkway around 3z.
This activity should weaken/dissipate as lingering instability
wanes. Further east, expect just an isolated shower or sprinkle
through 3z.
UPDATE Issued at 625 PM EDT SUN AUG 1 2021
A line of low-topped convection is dropping across far
northeastern Kentucky this evening, just brushing Fleming and
Rowan County with some light to moderate rainfall, a quick 8-10
degree temperature drop, and a blustery NW-N wind gusting 15 to 30
mph. Strong capping at about the -10C level seems to be keeping
the convection free of lightning at this time although a couple
of cells were able to punch through the cap, up to around -15 to
-20C, and produce a few lightning flashes earlier near the Ohio
River. Expect that the current line of broken activity will
continue to push southeastward at about 25 knots reaching an Inez
to Salyersville line around 8 PM or so. Some additional shallow
convection is also present from just south of CVG back into
southern Indiana. If this activity is able to maintain, expect
additional isolated to widely scattered showers sinking
southeastward across all but far southern Kentucky during the
mid-to-late evening hours. Introduced low chance PoPs and thunder
all the way to the Hal Rogers Parkway. Given steep low- level
lapse rates and 900-1000 J/kg of DCAPE, the more robust showers
could produce some gusty winds but meager MLCAPE (100-500J/kg)
and strong capping above 500-600 mb will keep the cells from
realizing their full potential. A lightning strike is also
possible with any cell that briefly surges above the cap.
&&
.SHORT TERM...(This evening through Monday night)
Issued at 425 PM EDT SUN AUG 1 2021
Eastern KY is currently quiet with current temperatures ranging
from the upper 70s to around 80 degrees across the area. The 19Z
surface analysis shows high pressure dominating over the western
CONUS and Northern Plains while a low pressure system resides over
the Northeast. A cold front, associated with the low pressure
system, is draped through the Ohio valley back into the Central
Plains. A fair weather cumulus field has developed over the area
and should persist into the evening.
The models continue to show decent agreement in the upper level
pattern for the short term period. An upper level trough is
positioned over the Upper Great Lakes and will continue to
progress, east leaving us in a more zonal flow aloft before
another trough drops down from the Great Lakes region. This will
cause lowering heights aloft over the area into Monday.
The aforementioned cold front will move southward, weakening as it
approaches the CWA. Cloud cover across the area will increase late
this evening into the overnight hours, bring partly cloudy skies
for most of the night. A chance for storms and showers is possible
with the passage of the front this evening but should remain
along and north of I-64. Low temperatures will be in the upper 50s
to low 60s with areas of fog possible and denser fog expected in
the deeper river valleys. Monday will be dry and pleasant as high
pressure continues to dominate to the northwest. Mild temperatures
in the upper 70s to low 80s and mostly sunny to partly cloudy
skies will make for a comfortable day to spend outside. Fog is
expected Monday night but should be less widespread than the
previous night with the thickest fog forming in the river valleys.
Lows will be in the mid to upper 50s with partly cloudy skies.
.LONG TERM...(Tuesday through Sunday)
Issued at 315 PM EDT SUN AUG 1 2021
Unsettled weather this week with a trough from the OH valley down to
the deep south through mid week before lifting up to New England
towards the end of the week, while another trough from the northern
plains dives down and impacts the area Friday into the first part of
the weekend. At the surface, a frontal boundary will be across the
southeast and deep south states with multiple areas of low pressure
along the front. None of the days will be washouts, but there will
be a chance of afternoon and evening storms each day. Highest chance
Pops will be on Tuesday and Wednesday (25-50%) as a theta ridge and
increasing PWATS advect into the area. Lower chance Pops (15-30%)
Thursday through Saturday with more typical diurnally driven
convection expected those days.
Below normal temps Tuesday through Thursday with afternoon highs in
the lower 80s and low temps in the upper 50s to lower 60s. A bit
warmer for Friday into the weekend with high temps in the mid to
upper 80s and low temps in the low to mid 60s.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
ISSUED AT 819 PM EDT SUN AUG 1 2021
At 00z, VFR conditions were observed across the area. A
southward-dropping cold front was producing a band of variable
mid-level cloudiness north of the Mtn. Pkwy. with embedded
isolated to widely scattered light showers and virga along its
leading edge. This will continue to settle southward through the
evening and gradually dissipate toward the Hal Rogers Pkwy. Other
than some erratic wind shifts near the shower and virga activity
with the leading edge of this cloudiness, no impacts are expected
at the TAF sites.
Expect winds to become light and variable overnight in most
locations with areas of fog, locally dense, developing in the
river valleys. Some of this fog or low stratus is expected to
eventually creep out of the valleys and bring visibility
reductions to the SJS, JKL, and LOZ terminals early Monday morning.
Lingering mixing should keep SME fog-free for most of the night
but suspect that they too will decouple and eventually see some
visibility restrictions. Expect better mixing to keep VFR
conditions at SYM, but if winds go calm there, fog formation may
ensue.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GEERTSON
SHORT TERM...BATZ
LONG TERM...CMF
AVIATION...GEERTSON
Area Forecast Discussion
National Weather Service North Platte NE
616 PM CDT Sun Aug 1 2021
.SHORT TERM...(This evening through Monday night)
Issued at 209 PM CDT Sun Aug 1 2021
Mostly quiet weather expected through the short term period. The main
weather concern will be possible sfc smoke in the early morning.
The HRRR near sfc smoke model runs show some return of sfc smoke
early Monday morning, with the greatest area west of hwy 83.
Decided to add patchy smoke into the forecast briefly for the
morning hours as particulates will likely get trapped in the
inversion. Although fog conditions are marginal, there is some
concern that the smoke particulates trapped near the sfc will
help to induce fog development towards morning, especially in the
valleys. As the inversion mixes out by mid morning, smoke/fog
concerns will diminish and sfc smoke is not expected to linger.
For now have left the forecast with just patchy smoke.
For Monday afternoon the HRRR continues to suggest lingering
smoke in the upper levels, so have kept haze across a good
portions of the forecast area through late afternoon.
.LONG TERM...(Tuesday through Sunday)
Issued at 209 PM CDT Sun Aug 1 2021
There will be minimal chances for precipitation in the long term. An
upper level high continues to sit across the southwest CONUS as
northwest flow dominates through most of the work week. There will
be weak disturbance that moves through Wednesday. Moisture is
expected to return across central and north central Nebraska, but
is lacking a little across western Nebraska. Showers and
thunderstorms may be possible Wednesday afternoon and evening, the
better chance would be across north central and central Nebraska
where there would be more moisture available, but even then
precip chances are isolated at this time.
Temperatures warm into the 90s for the weekend as the ridge
becomes centered over the high plains region. As for
precipitation chances beyond Wednesday, there will be a weak
disturbance Friday night and again Saturday night that could lead
to precipitation chances, however at this time confidence is low
in anything widespread.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 613 PM CDT Sun Aug 1 2021
Mostly VFR conditions are expected through the TAF period. There
is still some existing smoke in the atmosphere creating hazy
conditions. As such, have placed a tempo group in for KLBF, and
southern Neb terminals, that indicate MVFR VIS conditions at
times (down to 4SM). Otherwise, winds will be under 10kts, but a
bit variable at the sfc. They will be generally from the south,
but may transition between southerly, southeasterly, and
southwesterly at times. There are no other flight concerns ATTM.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SHORT TERM...Gomez
LONG TERM...Gomez
AVIATION...Sinclair
Area Forecast Discussion
National Weather Service Lake Charles LA
957 PM CDT Sun Aug 1 2021
.UPDATE...
Forecast is largely on track tonight with only a couple of small
adjustments needed at this time. Firstly, tweaked hourly POPs
over the next few hours to account for current radar trends,
mainly for the isolated convection ongoing across southern
Acadiana. Also tweaked hourly temps to account for current obs
going into the overnight hours. Otherwise, still expected a wetter
and slightly cooler pattern to begin tomorrow, as a frontal
boundary heads towards the coast through the mid-week.
17
&&
.PREV DISCUSSION... /issued 639 PM CDT Sun Aug 1 2021/
AVIATION...
Isolated storms around southeast Texas and southern Louisiana are
on the wane this evening although a few storms over by Baton
Rouge continue to persist. Looking at all the precip out of the
area by 02z but will see some redevelopment after sunrise tmrw as
a weak boundary from the northwest and the C-brz collide over the
region tomorrow afternoon.
PREV DISCUSSION... /issued 358 PM CDT Sun Aug 1 2021/
DISCUSSION...
SHORT TERM [Today through 12Z Wednesday]...
Showers and thunderstorms continue to develop throughout the area
and will be expected to dissipate during the evening hours with loss
of daytime heating. A frontal system will be making its way into our
area tomorrow which will cause increased chances for thunderstorms
starting in the early morning. There will be a broad area of
convergence throughout the area tomorrow morning which may cause the
development of widely scattered thunderstorms. As the morning
progresses into the afternoon, daytime heating will aid development
leading to numerous/widespread showers and thunderstorms through the
afternoon and evening. The 12Z HRRR shows much of the convection as
being disorganized. However, the late evening and overnight hours
could see the formation of a squall line of thunderstorms as the
front continues to push south (with forced uplift) and tap into
moisture from the Gulf of Mexico. WPC has our area in a Marginal
Risk of Excessive Rainfall 12Z Monday through 12Z Tuesday.
Significant accumulation will be expected which could lead to
flooding.
The front will provide enough instability to keep precipitation
chances elevated through to the end of the period.
55
LONG TERM [Wednesday through Sunday]...
The unseasonal, but most welcome frontal boundary is expected to
stall over the northern gulf by Wednesday morning. Scattered to
widespread showers and thunderstorms are likely to persist over the
coastal waters in the vicinity of the front. As with the previous
cycles, NBM along with most of the regularly produced blended
guidance appear to be significantly overestimating inland PoPs both
Wednesday and Thursday likely due to the inclusion of previous, less
certain, runs as part of their algorithms. The official forecast
pares PoPs back to isolated along and south of the I-10 corridor and
even this may be generous should the front make it further offshore
than currently projected.
Both high and low temperatures behind the front will be marginally
"cooler" although afternoon highs will still climb into the lower
90s. Dewpoints, however, will drop back into the mid to upper 60s
across central Louisiana and lower 70s closer to the coast which
will keep heat indices more tolerable through Thursday.
The frontal boundary will gradually wash out over the coastal waters
as a weak surface high develops across the northeastern gulf Friday.
This will turn low level winds back out of the south and push gulf
moisture back across the region. The upper trof responsible for the
frontal passage will lift off to the northeast as a second trof digs
out of Canada across the central U.S. No real change in airmass with
this trof, but it will likely provide better upper level support for
diurnally driven convection into next weekend.
Jones
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 75 89 73 89 / 40 100 70 50
LCH 78 91 74 89 / 40 90 90 80
LFT 77 91 75 89 / 40 90 90 80
BPT 77 92 74 89 / 30 80 90 80
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...None.
TX...None.
GM...None.
&&
$$
Area Forecast Discussion
National Weather Service Louisville KY
736 PM EDT Sun Aug 1 2021
...Updated Aviation Discussion...
.Short Term...(This evening through Monday)
Issued at 300 PM EDT Sun Aug 1 2021
Latest GOES imagery shows scattered cu field across much of our
region with some haze mixed in. More congested area of clouds
blanket counties just north of our CWA, associated with a south-
bound cold front that is attached to a sfc low currently located
over Lake Ontario. Regional radar shows a line of progressive
showers already developed over east-central IN and central OH and
tracking to the southeast. As this cold front arrives in our region
this evening, some isolated showers are possible despite a
relatively dry environment with PWATs around 1.1 inches. Hi-res
model consensus is that counties east of I-65 will have the best
chance of a shower, which agrees well with RAP guidance on
suggesting slightly better moisture convergence to our east.
Additionally, model soundings show a strong inversion around 700-
600mb developing this afternoon, which will limit any updraft
growth, resulting in shallow showers and light QPF. Will limit PoPs
to no more than a slight chance, and believe more people will remain
dry than those that do observe any precip.
Other topic of discussion for this afternoon and evening is the
haze/smoky conditions from western wildfires. Expect these hazy
conditions to remain through this evening, providing a red-orange
sunset, before clearing out of southern IN and Louisville Metro by
05z, and Lexington/Bowling Green by 08z. With mostly clear skies and
relatively calm winds overnight, expect to have some early morning
patchy fog develop across our southern CWA, specifically the
Cumberland Parkway corridor and Bowling Green region. Fog should
burn off quickly after sunrise tomorrow morning, but some folks with
an early commute could see some rapid changes to visibilities.
Temperatures for tonight will range from mid 50s across southern IN
to low 60s across south-central KY.
Tomorrow will be a rather comfortable and mostly sunny day across
the region, with temps expected to stay in the upper 70s to low 80s,
with dewpoints in the upper 50s and near 60. Haze looks to make a
return to Louisville and Lexington by tomorrow afternoon.
.Long Term...(Monday night through Sunday)
Issued at 245 PM EDT Sun Aug 1 2021
===================================
Synoptic Overview
===================================
Overall pattern for the upcoming week is similar to the overall
pattern that we`ve seen so far this summer. Broad upper ridging is
forecast to persist across the western US with a troughing centered
east of the Mississippi River Valley. This pattern looks to hold
steady through at least mid-week. Towards the end of the week, the
broad trough axis over the east is expected to deepen and will
likely close off. This upper low will likely remain over the Ohio
Valley for the late part of the week which will likely fuel
diurnally driven convection over parts of the area. By next
weekend, the pattern is expected to flatten out a bit and become a
bit more progressive, yielding seasonal temps but episodic bouts of
precipitation.
===================================
Model Discussion/Preferences
===================================
Deterministic and ensemble guidance remains tightly clustered and in
remarkable agreement through much of the forecast period.
Increasing, but normal spread begins to show by day 4 and continues
through day 7. Overall, the spread is not bad and certainly lower
than normally seen out through day 7. Given the good agreement, the
blended model suite looks to be a good basis for the upcoming
forecast.
===================================
Sensible Weather Expected
===================================
In terms of sensible weather, cooler than normal temperatures with
lesser amounts of humidity are expected through mid-week. Morning
lows will start off in the upper 50s across southern Indiana and
northern Kentucky with upper 50s to the lower 60s across southern
Kentucky. Daytime highs on Tuesday will be in the upper 70s to
around 80. Highs on Wednesday should be similar, though southern
Kentucky should warm solidly into the lower 80s. Inverted surface
troughing may take shape by Wednesday as aforementioned upper low
closes off over the eastern part of the Ohio Valley. That should
allow for scattered convection to develop over mainly eastern KY
(along and east of the I-75 corridor). Previous forecast had this
covered well and the latest data continues to support that trend.
With the upper level low nearby, we will likely see mainly diurnally
driven convection fire each afternoon from Thursday through
Saturday. Overall, this doesn`t appear to be a washout by any
means, but the highest chances of precipitation look to remain east
of the I-65 corridor through the period.
Temperatures Thursday through Saturday will continue to run slightly
below normal with highs mainly in the lower-middle 80s and overnight
lows in the 60s.
===================================
Forecaster Confidence
===================================
Temperatures: Medium to High through the period.
Precipitation: Medium to High through Wednesday.
Medium Thursday through Sunday.
&&
.Aviation...(00Z TAF Issuance)
Issued at 735 PM EDT Sun Aug 1 2021
Scattered showers have developed along a cold front pushing south
through southern IN and northern KY this evening, so did include a
brief VCSH at SDF and LEX. Northwesterly winds veer northerly
tonight in the wake of the front and diminish slightly after sunset.
Haze will continue to lower visibility into the 6-8 SM range this
evening. Expect light northeasterly winds on Monday with just some
sct afternoon cumulus.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...None.
KY...None.
&&
$$
Short Term...CJP
Long Term...MJ
Aviation...EBW
...Updated Aviation Forecast Discussion...
.DISCUSSION...
Issued at 311 PM CDT Sun Aug 1 2021
Northwest flow aloft will dominate the region the next several
days. In the short-term this will allow for smoke to continue over
the area, though lessened, through tomorrow at least. The latest
HRRR smoke forecast depicts smoke lingering more into western Iowa
and central Nebraska through the evening and overnight hours.
Otherwise quiet weather will be the rule. A weak shortwave passes
through the area Wednesday night but with an overall meager
moisture profile precipitation chances are not great and barely
worth mentioning. The main focus the next week is the building
heat. By next Friday daytime highs return to the 90s, possibly
reaching 100 in some areas by next Sunday. This coupled with
dewpoints in the 60s and low 70s will push heat index values to
around 105, flirting with heat advisory criteria for a large
portion of the area.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 611 PM CDT Sun Aug 1 2021
VFR conditions (visibility greater than 6 SM and SKC-SCT AOA 5000
ft AGL) should be predominate through the next 24 hours. There is
about a 30% chance for reduced visibilities (3-6 SM) due to smoke
between 12Z and 23Z Monday. However confidence in these
visibility restrictions was to low to warrant there inclusion in
the TAFs (KOMA, KLNK or KOFK) at this time. Winds should remain
light and variable through the next 24 hours.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...None.
IA...None.
&&
$$
DISCUSSION...Pearson
AVIATION...Albright
Area Forecast Discussion
National Weather Service Mount Holly NJ
818 PM EDT Sun Aug 1 2021
.SYNOPSIS...
A cold front will cross the region tonight, at the same time a wave
of low pressure passes well offshore. High pressure builds in for
Monday and Tuesday. A frontal zone will set up near our coastline
for the midweek period, with multiple waves of low pressure tracking
along it. High pressure may build back in towards the end of the
week or next weekend.
&&
.NEAR TERM /THROUGH MONDAY/...
Showers with some isolated embedded thunderstorms associated
with a cold front are approaching the region from the north and
west. These shower are the result of a strong upper level trough
digging into the region with quite a bit of mid/upper level
shear. However as we head into the overnight hours the
instability will wane and the showers will start to lack the
support for stronger updrafts. The HRRR shows this quite well as
the vertical velocities dramatically weakening over our area.
The forecast largely had this covered and so no significant
changes were made to the forecast other than to slightly delay
the timing of the precip over the southern portion of the
forecast area. The cold front approaching from the northwest is
then anticipated to pass through our region late tonight,
bringing a decrease in cloud cover by daybreak on Monday. Monday
should then be mostly sunny with a NW breeze and highs in the
70s to low 80s.
&&
.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/...
High pressure continues to control the weather Monday night into
Tuesday. Monday night looks like a cool one under favorable
radiational cooling conditions, with lows likely falling into
the 50s outside of the warmer urban centers and Delmarva.
Tuesday looks like a pleasant day as well. A shift to light
onshore flow is likely as the center of high pressure weakens
and shifts offshore. Tuesday will also offer noticeably more
cloud cover, mainly in the form of mid and high level clouds and
especially towards the coast. This will come as a baroclinic
zone offshore becomes more convectively active to our south,
with mid and upper level winds carrying cloud tops northward.
Locally, however, dry weather is expected to prevail due to lack
of forcing and a large amount of dry air remaining in the low
to mid levels. Temperatures look similar to Monday, near 80 in
most areas.
By Tuesday night, rain chances start to creep up in the southeastern
portion of the area as the first of several surface waves starts to
approach along the baroclinic zone. Even then, however, timing and
track of the wave should work out such that any rain should remain
confined to areas near the coast. Areas along and northwest of I-95
will stay dry through Tuesday night. Lows favoring the upper 50s and
low to mid 60.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
Overview...
The big story for the long term will be the return of sustained
humidity as our region becomes entrenched in a funnel of moisture
between an offshore Bermuda High and Great Lakes/Ohio Valley
troughing. Little change in thinking to the previous forecast, with
the main source of uncertainty being precipitation chances as
several waves of low pressure track along a nearby baroclinic zone.
It looks like most of these waves will largely stay offshore, though
at least one on Thursday may deliver a soaking rain. The end of the
work week and next weekend then look to transition to a very typical
summer pattern of warm and humid weather and spotty, diurnally
driven convection.
Dailies...
Wednesday-Wednesday night... Latest trends suggest Wednesday has a
good chance to remain mostly dry, especially away from the coast.
The 01.12z NAM was an outlier in showing a soaking rain on
Wednesday, and have largely discounted it. Most indications are that
the flow will not amplify enough on Wednesday to draw that wave very
far northwest. For PoPs, split the area roughly into thirds from
northwest to southeast, with values ranging from below mentionable
(northwest) to slgt chc (central) up to chc (southeast). Highs
mainly in the low 80s are expected. A similar theme with the rain
chances through the night with lows from the upper 50s to mid 60s.
Thursday-Thursday night... If there`s going to be a washout day this
week, it will be Thursday. The GFS is trending more towards the
EC/UKMET solutions of bringing the next frontal wave directly over
the region, though the GFS still shows it just scraping the coast.
Raised PoPs to likely over much of the region. The wave looks fairly
progressive, but the EC/UKMET do show it producing significant
rainfall in a fairly short amount of time. So we will have to keep
an eye on excessive rainfall potential. The wave should start to
pull away by Thursday night.
Friday-Friday night... Most guidance suggests the wave from Thursday
departing by Friday, leaving drier weather in its wake. With more
sunshine, temperatures should rise well into the 80s with fairly
high humidity on light southwest flow. This could lead to some
spotty air mass showers or storms in the afternoon. Because of this
and the low chance of a slower departure of the Thursday wave, still
have slgt chc PoPs for much of the region. But overall this is
looking like a mostly dry day and night.
Saturday-Sunday... Southwest flow likely continues into the weekend,
leading to a little more warming and a continued increase in
humidity. Rain chances look fairly limited, but some isolated,
weakly forced convection could be possible on either day. As usual
at this range, some room for change in next weekend`s forecast, but
definitely looks like what you would expect for the first weekend of
August.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY and surrounding areas.
Tonight...Mainly VFR. MVFR...both ceilings and visibilities...
possible during the evening hours due to showers and thunderstorms.
Best chance of thunderstorms from the I95 terminals north and west.
S winds 10 kts or less, becoming NW. Generally high confidence,
except for the thunderstorm placement.
Monday...VFR. NW winds 5-10 kts gusting to 15 kts during the late
morning and afternoon hours.
Outlook...
Monday night-Tuesday... VFR. Near calm winds Monday night. Winds on
Tuesday will become northeast then shift to southeast, but with
speeds only around 5 kt, and they may remain light and variable in
some areas. High confidence.
Tuesday night... Initially VFR. The development of sub-VFR
conditions is possible southeast of PHL and especially near the
coast as the night goes on. Winds mostly light and variable or calm
but favoring onshore directions if anything. Moderate confidence.
Wednesday-Wednesday night... Mainly VFR for areas near and southeast
of PHL, though cannot rule out some MVFR. A better chance of
restrictions towards the coast, especially near ACY. East-northeast
winds 5 to 10 kt, decreasing overnight. Moderate confidence.
Thursday-Thursday night... MVFR/IFR possible in rain, which may be
heavy. Light northeast winds shifting to southeast during the day
then becoming light and variable at night. Moderate confidence.
Friday-Friday night... Mainly VFR. Light southwest winds. Moderate
confidence.
&&
.MARINE...
Winds should continue to be south to southeast 10 to 15 knots
through this afternoon. The wind is expected to shift to the
northwest tonight with the arrival of a cold front. Waves on our
ocean waters should range from 2 to 3 feet with waves on
Delaware Bay at 2 feet or less.
For Monday, Seas 3-4 ft with NW winds sustained around 10kts with
gusts to 15kts.
Outlook...
Monday night-Friday... Mostly sub-SCA conditions expected. A couple
of wind shifts expected but gusts mostly 20 kt or less through the
period. Seas 2 to 4 ft, possibly close to 5 ft during the midweek
period. Frequent opportunities for showers and isolated
thunderstorms from late Tuesday onwards.
Rip currents...
A southeast wind 10 to 15 MPH is expected for today. Breaking
waves around 2 feet are anticipated with a medium period
southeasterly swell. The forecast conditions should result in a
LOW risk for the development of dangerous rip currents. However,
the risk may approach moderate in spots this afternoon, so use
extra caution if entering the surf.
The wind is forecast to be from the northwest on Monday morning
with a sea breeze possibly developing in the afternoon.
Breaking waves are again expected to be around 2 feet and the
rip current risk will likely be LOW.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...None.
NJ...None.
DE...None.
MD...None.
MARINE...None.
&&
$$
Synopsis...O`Brien
Near Term...Deal/Fitzsimmons
Short Term...O`Brien
Long Term...O`Brien
Aviation...Deal/Kruzdlo/O`Brien
Marine...Fitzsimmons/O`Brien