Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 08/29/22
Area Forecast Discussion
National Weather Service La Crosse WI
639 PM CDT Sun Aug 28 2022
.DISCUSSION...(This evening through Sunday)
Issued at 247 PM CDT Sun Aug 28 2022
Key Messages:
- Severe potential tonight with showers/storms
- Dry weather this week
Tonight
GOES water vapor imagery showing the broad long wave trough
across the Dakotas with embedded shortwave troughs at 19Z...the
most significant appearing to be on the ND/SD border shifting
east. This system will bring a cold front through overnight and
provide upper level support to severe storms to the northwest of
the area.
A tight convectively enhanced shortwave trough is now approaching
Dubuque at 19Z and is providing a bit of enhanced wind shear across
a destabilizing air mass over nrn IL and srn WI. SPC has put out a
Severe Thunderstorm Watch east of the forecast area. We continue to
monitor, but track of the wave and storms on radar appear on track
to our east.
GOES visible showing that finally clouds are clearing over MN and
destabilization of the boundary layer is now occurring. Clearing is
expected to work into the area from southwest to northeast,
becoming more aggressive as the Dubuque wave moves out. Storms
are expected to develop across central MN this evening, where
convergence is already seen east of surface low pressure near
Aberdeen SD, and shift into the area overnight. Normally the diurnal
cycle and stabilization would lead to weakening storms. However,
28.12Z HREF and RAP suggest a surge in low-level moisture (Surface-
850 mb), allowing for reduced elevated parcel capping and MUCAPEs
growing ahead the front into the 2500 J/Kg range. Steep mid-level
lapse rates to 8C/km over the area contribute to a careful approach
to the overnight storms. The front approaching
has good 850-925 mb theta-e convergence and 850 mb moisture
transport convergence at mid-evening to our northwest. So, we are
expecting a line of storms to move through much of the area. Wind
shear for what should be elevated storms is very weak /1-7km Bulk
Shear 10 kts/. So while a line of storms is expected because of
linear forcing, organized wind and hail threats seem limited. Pulse
hail storms in this thermodynamic environment could cause localized
severe hail and downburst wind gusts, but more organized storms are
not expected. A general weakening to the storms overnight is
probable and the SPC risk of Slight>Marginal>General across the area
reflects that. Timing of the storms will be in the late evening in
southeast MN, with storms should exiting swrn WI by 4-5 am.
Monday into Tuesday
Cold front will push south of the forecast area Monday morning.
Subsidence behind surface front will erode much of the low level
moisture/convection south of the forecast area. Upper level trough
over the Great Lakes region may produce isolated diurnal showers
across the very far northern parts of the forecast area per bufkit
soundings. However...confidence is very low and scattered cumulus
may only develop from this. Have added a very small chance for
showers after 21z Monday over the far north.
Main upper level trough tracks across the Great Lakes region Monday
night into Tuesday. Lack of moisture per relative humidity
fields/bufkit soundings will keep forecast area dry. Under upper
level trough cooler airmass advects into the forecast area with
28.12z GFS/NAM 925mb temperatures cooling to plus 14 to plus 17
degrees celsius by 18z Tuesday. High temperatures are expected to
rise mainly in the 70s Tuesday.
Wednesday through Sunday
Main forecast concerns Wednesday through Sunday are mainly
temperatures through the period. Northerly flow aloft over the Great
Lakes region will filter in slightly cooler temperatures than normal
across the forecast area Thursday. Then...upper level ridge builds
into the Upper Great Lakes/Northern Plains Friday into next weekend.
Light southerly winds aloft/surface will allow for gradual warming
of temperatures aloft over forecast area. Latest 28.12z GFS/ECMWF
show 925mb temperatures warming to near plus 20 degrees celsius by
00z Sunday. Temperatures across the forecast are expected to
gradually warm from highs mainly in the 70s Thursday to the upper
70s to middle 80s Saturday/Sunday. Subsidence underneath upper ridge
will inhibit any convection across the forecast area Wednesday into
Sunday and much of the forecast area is expected to remain dry
through the period.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 639 PM CDT Sun Aug 28 2022
Despite patchy MVFR ceilings early this evening near KRST, mainly
VFR conditions are expected early this evening. A broken band of
storms remains likely to move through overnight (29.04Z-29.09Z). A
more organized line of storms likely would impact TAF sites
slightly sooner and pose a risk for gustier winds, while a less
organized line would be slightly delayed with a lower risk for
stronger wind gusts. Upstream trends will be monitored this
evening. MVFR/IFR vsbys/ceilings could accompany storms for a
brief period. VFR conditions are expected as storms depart with S
winds gradually shifting W into Monday, gusting around 20 kts by
afternoon.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
DISCUSSION...Baumgardt/DTJ
AVIATION...JM
Area Forecast Discussion
National Weather Service Binghamton NY
832 PM EDT Sun Aug 28 2022
.SYNOPSIS...
Hot and humid conditions are expected Monday and Tuesday. Showers
and thunderstorms return Monday night, but will be more likely
Tuesday. Some of the storms on Tuesday may become strong with gusty
winds.
&&
.NEAR TERM /THROUGH MONDAY NIGHT/...
830 PM Update:
Forecast is on track for tonight and Monday. Heat related
impacts are possible, but the index numbers we`re getting are
right on the edge of Advisory for a small coverage of the area.
Only made very subtle adjustments to sky cover and some
temperature and dewpoint trends based on the lastest guidance
tonight. This also expanded the patchy fog coverage in our
gridded forecast, but does not really change the overall
message.
18Z NAM was too aggressive with QPF in our NEPA zones this
evening with only its high resolution CAM in agreement and its
spurious reflectivity simulations will be discounted the rest
of the night. HRRR keeps us dry overnight and this is the going
forecast. Low clouds will creep into the Poconos and Sullivan
county overnight, otherwise partly cloudy and muggy elsewhere.
345 PM Update:
A ridge of high pressure will dominate most of this period.
While mostly rain-free, warm and humid conditions are expected
to continue through at least Monday night as southwest flow will
advect much warmer air into the region.
Low-level moisture will be present over portions of NEPA and the
Catskills overnight, leading to mostly cloudy conditions. Winds will
be fairly light, so some patchy fog will be possible in the valleys
south of the Southern Tier, though coverage will be quite limited as
winds should be stronger than last night. Guidance had some fog in
the western portions of the Southern Tier (Elmira area), but
confidence is lower there due to some drier conditions and stronger
winds. It will be a warm night as temperatures only fall into the
60s and low 70s.
Hot and humid conditions are likely Monday. Using a blend of the
National Blend of Models (NBM) and the bias corrected Conshort,
temperatures are expected climb into the mid 80s to low 90s
with dewpoints in the upper 60s to low 70s. This will result in
heat indices around 95 in the Finger Lakes region and lower
elevations across the region. The decision was to hold off on an
advisory for now as there is some uncertainties with what
happens tomorrow afternoon. First, BUFKIT soundings do show
limited low to mid level moisture, which could result in pop-up
cumulus like today. Additionally, a couple shortwaves within a
deepening trough to the west could ride the ridge and bring
showers and thunderstorms into portions of CNY, though most of
the CAMs have backed off on that as well. For now, we continue
to highlight the risk for the hot and humid conditions in the
HWO, but it is looking like an advisory will be needed for
portions CNY. Winds will be gusty tomorrow, though will likely
not provide any relief from the heat.
Rain and thunderstorm chances will be better Monday night, though
will be limited to Western and Central New York. Scattered
showers/storms could just skirt across the northern portion of the
region with the highest PoPs along and north of the Thruway
Corridor. Another warm night is expected with temperatures once
again only falling into the 60s and low 70s.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
300 PM Update
Active weather to start the short term period, with warm, humid and
potentially stormy conditions on Tuesday...this gives way to
clearing and less humid weather by Wednesday.
An upper trough becomes negatively tilted as it moves into the
Northeast on Tuesday. Modest convective available potential energy
(CAPE) around 1000+ J/Kg and decent deep layer shear around 35 kts
are depicted in the models, pointing to possible strong storms with
gusty winds. However, it is not straight-forward and will depend on
cloud cover during the morning/midday out ahead of the front. A
ribbon of 1.8-2.1 inch precipitable water (PWATs) extends up the
front, we get more of a moist-adiabatic look to thermal profiles,
with taller skinnier CAPE and weak mid-level lapse rates. This along
with a lack of a dry air pocket to help mix down stronger winds, and
potential for significant incoming cloud cover to hold back diurnal
heating, presents a good deal of uncertainty for whether stronger
convective potential can be realized. Will need to watch this
potential for organized convection closely though. The timing of the
front seems to be trending a touch slower, which may allow for more
daytime heating in parts of the area. Current forecast highs are in
the mid to upper 80s, with even low 90s in the Wyoming Valley
region. Dew points will remain quite elevated, around 70
degrees...this will mean high heat indices once again, well into the
90s for portions of the area.
There is plenty of confidence in general rainfall for the whole
area, though, with areal averages ranging from around a half inch
inch to 1.5 inches, especially for the NY Thruway counties.
Topographic enhancement may occur in higher terrain areas as well,
from Poconos-Catskills to the hillier portions of Central NY. Cloud
layer and low level jet flow will become nearly front-parallel, so
there could be back-building and training of showers-thunder.
Elevated warm cloud depths of 11-12 kft also point to potential of
locally heavy efficient rainfall. Almost all of this rain will be
more helpful than anything, but localized poor drainage flooding
cannot be ruled out such as if training occurs over an urban area;
therefore WPC has the whole CWA under a marginal risk for excessive
rainfall.
Forced ascent from the right entrance region of an upper jet will
lag a ways behind the front, which may cause lingering anafront-type
showers to last into Tuesday evening before ending later Tuesday
night. Temperatures will settle into the upper 50s-lower 60s, likely
with areas of low clouds and patchy fog thanks to the surface
moisture of prior rainfall.
An inverted surface ridge builds over the region on Wednesday, along
with a very dry post-frontal air mass. 850mb temperatures do drop
substantially to around +10C Wednesday afternoon. Even so, any
response off Lake Ontario looks to hold off until the secondary
trough swings Wednesday night. Therefore, Wednesday is shaping up as
a pleasant weather day, mostly sunny skies breezy west winds 10-20
mph and highs reaching the mid-70s to lower 80s. As mentioned above
the secondary trough axis swings through Wednesday night, which
could keep a few isolated lake effect showers going north of the NY
Thruway in Oneida county. Otherwise, it`s drier and cooler with lows
in the 50s areawide.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
300 PM Update
Turning much cooler, with lake effect rain showers for parts of the
area Thursday. The upper level trough will be overhead as 850mb
temperatures drop to around +4C and with moisture extending up to
around 700mb in the west-northwest flow it is looking like a better
chance for lake effect showers to develop. Increased PoPs above what
the NBM was showing for the Syracuse metro area and along the NY
Thruway corridor...a few showers may also push into the hills south
of Syracuse with more cloud cover. Temperatures continue to trend
cooler, with highs now only progged in the mid-60s to lower 70s for
CNY, with 75-80 still across the Wyoming Valley.
West winds also veer to out of the northwest behind a secondary
front Thursday, with breezy winds of 10-20 mph again. Things begin
to dry out Thursday night as high pressure builds overhead. Low
temperatures fall into the upper 40s and lower 50s.
The trough lifts out in favor of abrupt ridging Friday-Sunday, as
high pressure passes directly across the region. It will still be on
the mild side Friday, with mostly 70s-near 80, but warming will
become realized at the surface Saturday & Sunday as temperatures
climb into upper 70s-mid 80s. The pattern looks quite dry through
most if not indeed all of Labor Day weekend.
&&
.AVIATION /01Z MONDAY THROUGH FRIDAY/...
Aside from at KELM and KAVP, mainly VFR conditions are expected
to persist through at least the next 24 hours (at least through
00Z Tuesday). Lower clouds are expected to drop ceilings at KAVP
late tonight/early Monday morning to at least Fuel Alternate.
There is a possibility for brief IFR restrictions there, but
with IFR restrictions somewhat rare there with a southeast flow
due to downsloping, opted not to include IFR restrictions in
this set of TAFs. Some guidance is hinting at potential ceiling
restrictions at KBGM as well, but with lower confidence there,
opted not to include this in this set of TAFs.
Meanwhile at KELM, patchy IFR valley fog will again be possible
late tonight/early Monday morning; albeit with a lower chance
than last night. Fog will also likely be during a shorter
duration. With remaining uncertainty, opted not to drop visby
restrictions there to airport mins, but this cannot be ruled
out. Conditions are expected to return to VFR at KAVP and KELM
after 12Z/13Z or so.
Outlook...
Monday night through Tuesday...Occasional restrictions possible
in showers and thunderstorms, especially Tuesday afternoon
through Tuesday night.
Wednesday through Friday...Mainly VFR
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...None.
NY...None.
&&
$$
SYNOPSIS...BTL/JAB
NEAR TERM...BTL/JAB
SHORT TERM...MJM/MDP
LONG TERM...MJM/MDP
AVIATION...BJG
Area Forecast Discussion
National Weather Service State College PA
1041 PM EDT Sun Aug 28 2022
.SYNOPSIS...
An area of high pressure moving east off the New England Coast
will create a low level southeasterly flow off the Western
Atlantic. A cold front and upper trough will approach from the
Midwest/Upper Great Lakes. The front should pass through
Tuesday night. A huge high pressure system will then take over
for about a week, keeping it dry with seasonable temperatures
well into next week.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
830 pm update... Isolated showers have all but dissipated early
this evening, so we`ve removed any mention of them in the
forecast.
Early evening cloud microphysics satellite imagery, as well as
the latest mesonet data, are showing that the leading edge of an
area of lower stratus clouds is impinging on eastern Lancaster
county, near an outflow boundary from earlier thunderstorm
activity across southeastern PA/southern NJ. We expect a further
westward expansion of the lower cloud mass into the Susquehanna
Valley and the southwestern Poconos overnight. Although the
going forecast had this scenario pretty well in hand, we did
step up the timing of the onset of lower clouds in these areas
by several hours.
Lows by daybreak should range from the mid 60s over the higher
terrain of the Alleghenies and Poconos, to the lower 70s in
parts of the Lower Susquehanna Valley.
Previous discussion... Tweaked PoPs just slightly for the
latest update, spreading the isold 15-24pct PoPs into the
central mtns for a couple of hours late this aftn/eve. The radar
trends are matching with the gist of the latest NAM12 and it`s
finer mesh cousins, and these continue to generate convective
precip in the central mtns until a few hrs past sunset. However,
latest satellite trends show that away from the current SHRA
(no TS yet), there appears to be some level of stabilization.
While the coverage of SHRA will be <30pct of the land, it seems
like it is worth a mention for a brief time.
Earlier discussion... Clouds growing up fairly tall off the
ridges in the Laurels and Alleghenies. Some change from streets
of cu to cellular convection over the SE where the early stratus
has melted away. Near term mdl output from many sources does
generate convection of some repute over the Laurels, but not so
much in the SE anymore - probably due to the slowness of the
stratus to burn off in the SE, and good sunshine in the west.
Dewpoints in the mid 60s make it feel like summer. Have nudged
PoPs up into the mentionable range for the Laurels, but no
farther east, yet, despite some hints of convective precip over
the central mtns. RAP soundings seem just a tad too warm aloft
too far east to allow free/tall convection over a good portion
of the area this aftn and evening.
Sunset (or even before) should bring stability back into the area.
Dewpoints do not drop at all thru the night. It will muggy, esp in
the SE and cities where Td hangs around 70F. Some fog is possible
overnight, mainly in the S, and not so much the valleys of the N,
mainly since the temps probably don`t cool off as much as needed to
form widespread river valley fog. Mins of m60s-l70s. Low clouds try
to form over the n-cent mtns and also creep in from the east once
again, and keep temps up a deg or two vs. what they would be like
with just SKC/SCT clouds.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY NIGHT/...
A near-repeat of today is expected for Monday as the morning
clouds (and any fog) burn away and lead to growing cu. The hill
tops in the west and a slight dip in upper heights make for a
slightly better chc for a SHRA/TSRA in the aftn and evening in
the W, mainly the NW. Good srly flow keep the dewpoints high in
the 65-70F range. Maxes will likely be at or just 1F above
Sunday`s values.
A more-pronounced dip in heights and pre-frontal trough ahead of the
cold front approaching from the midwest will help increase chcs of
SHRA/TSRA over the W Mon night, and make them likely by morning in
Warren Co. The front seems to catch up to the trough by Tues
morning, getting very close to the CWA by 12Z Tues. Mins will be
kept very similar to Sun night mins, and they may be even higher in
the NW thanks to the clouds and WAA.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
1030 pm update... On the large-scale, after the passage of an
amplified upper-level trough across the northeastern U.S. just prior
to this period, the flow pattern becomes more zonal in nature
over time. The main features will become upper-level ridges
across the southern CONUS and a flat upper jet axis, with
several embedded short-waves, across southern Canada.
At the surface, the passage of a strong cold front by the
middle of this coming week, will be followed by sprawling high
pressure building down across the Commonwealth from central and
eastern Canada. This large fair weather system should lead to an
extended period of rain-free weather and comfortably low
humidity levels.
Thursday`s highs are expected to be at or a bit below seasonal
norms for early September, with readings ranging from the upper
60s over the northern mountains, to the lower 80s in the Lower
Susquehanna Valley. As this air mass modifies over time,
temperatures will exhibit a day to day warming trend, with highs
by next weekend back into the 80s for most, and perhaps around
90 in the Lower Susquehanna Valley. Cool early morning lows in
the 40s and 50s Thursday and Friday, will moderate back into the
mid 50s-mid 60s range over the weekend.
&&
.AVIATION /03Z MONDAY THROUGH FRIDAY/...
Cumulus have collapsed for the day and this forecast focuses on
the potential for lower clouds over the south and east overnight
thanks to a moist component off of the Atlantic. Will continue
to mention some fog across the S, since dewpoints will be near
70F there. More clouds (MVFR mainly) will be found at IPT/MDT/LNS.
The air gets warm again with sct-bkn cu again on Mon. Some
instability in the W will allow for a couple of SHRA/TSRA with a
little more coverage than this aftn. The approach of a pre-
frontal trough will increase clouds and the chc of SHRA/TSRA at
BFD thru Monday night.
Outlook...
Tue...Increasing chance of showers and t-storms with CFROPA
Tues/PM.
Wed-Fri...AM valley fog, otherwise no sig wx.
&&
.CLIMATE...
It`s been a hot and dry month so far in Harrisburg...
The average monthly temperature [through 8/27] is 78.7F or
+3.1F above normal and would rank as the 2nd warmest August on
record.
The total monthly rainfall [through 8/27] is 0.82" or -2.45"
below normal and would rank as the 4th driest August on record
at Harrisburg.
Hot temperatures are expected through Tuesday, followed by
cooler air moving in for the last day of the month on Wednesday.
Showers and storms with the cold front on Tuesday may
jeopardize this month remaining in the top 5 driest on record.
Warmest August on record at Harrisburg:
1. 79.1F 2016
2. 78.7F 2022 (4 days left in the month)
3. 78.3F 2021
T4. 78.2F 1900, 1966, 2020
7. 77.7F 2002
Driest August on record at Harrisburg:
1. 0.53" 1995
2. 0.73" 1923
3. 0.81" 1909
4. 0.82" 2022 (4 days left in the month)
5. 0.93" 1977, 1957
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...Dangelo
NEAR TERM...Jurewicz/Dangelo
SHORT TERM...Dangelo
LONG TERM...Jurewicz
AVIATION...DeVoir/Dangelo
CLIMATE...
Area Forecast Discussion
National Weather Service Des Moines IA
625 PM CDT Sun Aug 28 2022
...Updated for the 00z Aviation Discussion...
.DISCUSSION.../Tonight through Sunday/
Issued at 249 PM CDT Sun Aug 28 2022
Key Messages:
-- A few strong storms possible tonight northern/eastern Iowa
-- Keeping an eye on the Monday rush hour to mid-morning forecast
-- Dry, seasonal conditions Monday night through the end of the
week
Details: Showers have pushed nearly out of the state and remnant
mesoscale convective vortex has rotated out of northern Missouri
into eastern Iowa with convection developing ahead of it this
afternoon. This activity was associated with a lead shortwave trough
that is seen in GOES-East upper level water vapor imagery over the
region. For central Iowa, some low cumulus clouds are over parts of
central Iowa per GOES-East Day Cloud Phase Distinction RGB early
this afternoon. These clouds will not grow vertically this afternoon
as forecast soundings from NAM, RAP, and HRRR show that a warm
environmental mixed layer (EML) has the atmosphere capped. Thus,
will be a dry afternoon into early this evening as instability grows
with MUCAPE values in excess of 3000 J/kg. Soundings do show that
the EML weakens around 0z with a short window of surface based
potential possible, but unlikely given lack of surface convergence.
However, better convergence will arrive later this evening as a cold
front attached to a shortwave trough scoots eastward along the
US/Canadian border. This will bring a surge of theta-e advection
ahead of it along with surface convergence and higher effective
shear that may help to generate storms. The coverage into Iowa and
our forecast area is in question with a higher chance of storms
north and northeast of the state. The convective prone NamNest, FV3,
and WRF-ARW all kick off isolated to scattered storms late this
evening to a little after midnight that may skirt our far northern
and northeastern counties. The HRRR and NAM remain quiet in this
period as they were yesterday as well in this time frame. Soundings
over northern Iowa show that as the low levels cool, the reservoir
of better MUCAPE will reside around and above 700mb. There is
uncertainty of whether the parcels will lift from this level, which
would favor storm development and use of the MUCAPE, versus beneath
this level, which would impede storm development/coverage. If storms
do form overnight, the highest chances will be over far north
central through northeastern into east central Iowa. With the
nocturnal boundary layer having developed, these storms would be
relegated to an elevated nature. Hail would be the greatest risk due
to the steep mid-level lapse rates. Gusty winds are also possible
given the dry air around and above 700mb, but that would have to be
able to punch through the surface inversion.
This activity should depart a few hours after midnight with the
surface boundary laying out from northeastern into west central
Iowa. The 6z, 12z, and 18z HRRR have shown a convective cluster
developing somewhere in central Iowa along this boundary toward 12z
Monday, which will reside near the MUCAPE gradient. The NAM and RAP
also show development in a similar area. If these storms were to
develop, would need to monitor for possible strong to severe wind
gusts perhaps during the Monday morning rush hour into the mid-
morning hours as they move off to the east. Will continue to monitor
trends this evening and adjust forecast and messaging as appropriate
and needed.
The front may have additional showers and storms scattered along it
as it sinks southeastward out of the state. Better convective
development later Monday afternoon and evening looks to stay east of
the forecast area with a dry forecast Monday night onward through
the week. Ridging will amplify over the western US early this week
that will keep our area under northwesterly flow and with surface
high pressure over the High Plains, there will no return flow from
the Gulf of Mexico, which will keep dewpoints no better than the
50s. As the surface high moves over the state on Wednesday and
passes over the Great Lakes by Thursday, some return flow might
develop. There remains a signal that shortwaves will top the ridge
and suppress it westward later this week. Ensemble models do show
light QPF at times mid to late this week, but chances at this point
are slim and not well defined in time so have continued the dry
forecast.
&&
.AVIATION.../For the 00Z TAFS through 00Z Monday evening/
Issued at 623 PM CDT Sun Aug 28 2022
VFR conditions prevail through the current TAF period. Isolated to
scattered TSRA activity is possible overnight into Monday morning.
Included mention of VCTS at KDSM where recent model guidance has
consistently shown convection near/at the terminal. Confidence is
much lower elsewhere, and thus no mention at this time. TAF will
be updated as trends become more clear.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
DISCUSSION...Ansorge
AVIATION...Martin
Area Forecast Discussion
National Weather Service Quad Cities IA IL
1009 PM CDT Sun Aug 28 2022
.UPDATE...
Issued at 1008 PM CDT Sun Aug 28 2022
We are keeping a close eye on potential for showers and
thunderstorms across portions of eastern Iowa and northwest
Illinois Monday morning with the approach of a cold front from
the northwest.
A few of the convective allowing models, most notably the HRRR,
have been hinting at potential for a MCS to move across areas
around the Interstate 80 to Hwy 20 corridors during the mid-
morning to midday hours, with some potential for damaging winds as
it passes. This is low confidence scenario at this time, as the
HRRR looks to be an outlier when compared to the majority of other
CAMs. Despite favorable mid-level lapse rates, overall vertical
shear is weak and there will be a strong low-level inversion in
place during the morning hours per NAMnest/RAP/GFS soundings,
which could hamper development.
Regardless, we will be monitoring this potential through the night
as more 00z guidance arrives.
&&
.SYNOPSIS...
Issued at 1213 PM CDT Sun Aug 28 2022
Potent little MCV moving through the area at this time. With this,
it is generating a more robust vertical wind field, enhancing the
shear. Along with increasing wind shear, plenty of sun has allowed
parts of far eastern IA and northwest IL to heat up and build up
higher instability than initially advertised. Temperatures are
sitting in the low to mid 80s currently, coupled with dew points in
the low 70s. Thus, showers and storms have developed in the area and
will stand the chance to go strong to severe through the remainder
of the afternoon. Primary hazards will be gusty winds and a few
tornadoes. Southerly winds ahead of the MCV will continue to fuel it
through the afternoon.
&&
.SHORT TERM...(This evening through Monday)
Issued at 1213 PM CDT Sun Aug 28 2022
Busy short term forecast ahead of us, with a weak shortwave moving
through the area as I type this, and the stronger wave approaching
the area tonight. This smaller wave is the first feature that we are
watching, as this has a well developed MCV, which is expected to aid
in thunderstorm development through this afternoon. While much of
the action is already occurring, these showers and storms may
continue into the evening hours. Strong to severe storms are
possible with this, but widespread severe isn`t expected at the
moment.
A thin veil of cirrus ahead of the MCV has not stopped the surface
heating much, which helped increase instability when compared to
previous model runs. Along with increasing instability, an
enhancement in the wind field will also yield slightly higher shear.
With these two considered, the strong/severe threat is a little
higher than we initially thought. Currently, the SPC has highlighted
parts of our area in a Slight Risk for Severe Weather. This area is
focused north of Interstate 80 and along/east of the Mississippi
River. Currently, severe wind gusts are the primary hazard. A few
tornadoes cannot be ruled out either, given low level wind
enhancement and increasing moisture field. Frequent lightning and
heavy rainfall is also expected. PWATs are forecast to be 2.0" or
higher, which will very much favor heavy rainfall in any storm.
Tonight, we should remain relatively dry through much of the area.
With that said, we have kept Slight to Chance PoPs, especially in
our north/northwest. Moisture does not decrease much, which should
help keep temperatures in the low 70s. Model soundings favor modest
instability as well, which would favor some overnight convection.
Late tonight and into tomorrow morning, the larger wave approaches
the area, dragging along a cold front. An initial band of decaying
convection is expected to push through our area from the northwest
early Monday morning. Severe threat with these storms is low.
This can lead to some issues on convective initiation later in the
period.
Ahead of the boundary, a warm and humid airmass remains. Thus, we
could see another round of showers and storms tomorrow afternoon, as
long as the early morning convection doesn`t disrupt the environment
too much. Severe threat looks to be low, as we lack shear. Although,
modest instability ahead of the front may be enough to generate some
stronger storms. If we manage to get some strong storms, forecast
soundings favor isolated large hail and strong winds. Will continue
to iron this out though, as confidence is low. The front will be
slow moving. Past runs kept this front stalled out over our area
Monday night, but latest guidance wants to keep the front out of our
area, which should leave much of the area dry Monday night, with
temperatures in the upper 50s to low 60s and clearing skies.
.LONG TERM...(Tuesday morning through Saturday) Issued at 1138 AM
CDT Sun Aug 28 2022
Key Messages:
1. Quiet weather expected for the rest of the week as northwest
flow transitioning to ridging and high pressure is expected
across the area.
Discussion:
Models are consistent on a quiet weather pattern with gradual
heating as the NW flow moves out of the area and ridging builds in.
Dewpoints in the 50s through the whole time means much lower humidity
than of as late. Very nice sensible weather to end the month and
start September. Looking to the holiday weekend, highs in the mid
80s and increase dewpoints into the 60s will make for a warmer
holiday with no discernible chances of precip.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 611 PM CDT Sun Aug 28 2022
Primarily VFR conditions are expected for the terminals for this
TAF period. South winds to start will veer to the west midday
Monday while remaining around or below 10 knots.
Convective allowing models hint at a few chances of showers and
storms for the area tomorrow ahead of a cold front. The first
arrives early Monday morning around 08-10z, as a decaying line of
showers/storms dives southeast into the area from northern Iowa.
This will be a concern mainly for KCID/KDBQ, but confidence is low
on impacts given storms will be weakening. The next chance of
storms will arrive around 14-18z, and is being driven primarily by
the HRRR. The run-to-run consistency is enough to throw in a
PROB30 mention for storms for this time period at KCID/KDBQ/KMLI,
where MVFR conditions will be possible. Storms could also contain
gusty winds.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...Speck
SYNOPSIS...Gunkel
SHORT TERM...Gunkel
LONG TERM...Gibbs
AVIATION...Speck
Area Forecast Discussion
National Weather Service Austin/San Antonio TX
626 PM CDT Sun Aug 28 2022
...New AVIATION...
.SHORT TERM...
(Tonight through Monday night)
Issued at 231 PM CDT Sun Aug 28 2022
Partly cloudy to mostly clear skies are currently prevailing across
South-Central Texas this afternoon with light south/southeasterly
winds in place. Temperatures are in the upper 80s to middle 90s
across the area. Latest visible satellite imagery today versus
yesterday is a lot less congested with no showers noted as of yet on
area radars. In fact, with precipitable water values less than 2
inches areawide, latest runs of the HRRR keep most areas with the
exception of the Coastal Plains dry today. For tonight, mostly dry
conditions are expected to continue outside of a stray shower across
the extreme southeast by morning. Low stratus can be expected once
again for most locations with low temperatures reaching into the 70s.
Models had been showing a shear axis moving onshore beginning early
this week from the western Gulf of Mexico, but have since moved that
feature into the upper Texas Coast and Louisiana. As a result, rain
chances for tomorrow are lower than previously forecasted. Expect a
20 percent chance of rain for most areas in the west, to near 30
percent along the I35 corridor and into the 40-60 percent range in
the east where the best moisture will be located in addition to the
closer proximity to the weakness. High temperatures tomorrow will
once again be in the 90s. Another weak upper low will approach the
area from the northwest beginning Monday night and will continue a
30-40 PoP across the area for late Monday night as this feature
could produce some isolated to scattered showers and storms.
&&
.LONG TERM...
(Tuesday through Sunday)
Issued at 231 PM CDT Sun Aug 28 2022
An unsettled weather pattern remains on target for the long term
featuring daily chances for at least scattered convection. Moisture
levels will remain anomalously high with values generally ranging
from around 1.75 to 2.25 inches. On Tuesday, the region will be
sandwiched in-between an upper level disturbance across west Texas
and a mid-level shear axis from the northwestern gulf coast into
Louisiana. Latest model guidance show that pieces of vorticity may
occasionally try to strip off from these upper level disturbances
and move into the region at times. At the surface, a weak frontal
boundary will also try to advance into the central to north-central
half of the state midweek as well. During the end of the workweek
into the weekend, anticipate for continued broad mid to upper level
troughing to continue while the nearby surface front becomes more
diffuse with time. While the best rain chances seems to concentrate
around midweek, activity will be more mesoscale driven, which makes
it difficult to pinpoint favored locations.
Another potential weather feature to monitor for the upcoming
weekend will be a possible tropical wave coming out of the western
Caribbean, across the Yucatan peninsula and into the southwestern
Gulf of Mexico. Currently, the GFS and several of its ensemble
members remain the only support for any tropical development from
this feature with the help from a vort max originally coming off
Central America. Whereas the ECMWF and CMC along with their groups
of ensemble guidance indicate a much less organized trough that
enters into the Bay of Campeche. The 00Z ECMWF combines this with
broad troughing coming off Florida that may advance into the region
this weekend. Please follow National Hurricane Center`s Tropical
Weather Outlook for more information on any potential development.
As mentioned in the previous discussion, the details regarding the
rain chances and amounts will be refined through the week. Each of
the GFS, ECMWF and CMC ensemble means give the majority of the
region at least a 50 to 60 percent chance for exceeding 1 inch in
total QPF through Sunday while also favoring the Rio Grande Plains
and the southern Edwards Plateau with the highest probability of 2
inches or more. As is the case often in these mesoscale driven
convective processes, much higher pockets will occur in some spots
while others may receive much less.
Afternoon highs will trend below climatological averages for this
time of year. Highs in the upper 80s to low 90s will be common for
mid to late week as result of the increased cloud cover and area
rain chances. Conditions remain humid at night with overnight lows
ranging from the mid to upper 60s into the low to mid 70s.
&&
.AVIATION...
(00Z TAFS)
Issued at 626 PM CDT Sun Aug 28 2022
ISOLD SHRA/TSRA dissipate by 01Z or 02Z with no impacts to the sites.
ISOLD-SCT SHRA/TSRA will redevelop on Monday. There are higher PROBs
for impacts and have introduced VCTS mention for the afternoon into
early evening hours at the I-35 sites. Later forecasts may have to
update to go prevailing based on radar/model trends. VFR flying
conditions prevail this evening through Monday, except overnight into
mid Monday morning when MVFR CIGs are expected at the I-35 sites.
There may be brief restrictions to CIGs/VSBYs with any SHRA/TSRA on
Monday. Southeasterly winds prevail at 5 to 17 KTs with gusts up to
27 KTS possible.
&&
.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry 76 94 76 92 / 10 30 30 60
Austin Bergstrom Intl Airport 77 93 76 90 / 10 40 30 60
New Braunfels Muni Airport 76 95 76 92 / 10 30 30 60
Burnet Muni Airport 75 93 75 89 / 10 30 30 60
Del Rio Intl Airport 78 96 77 90 / 0 10 40 60
Georgetown Muni Airport 76 93 76 90 / 10 30 30 60
Hondo Muni Airport 77 95 77 93 / 10 20 40 50
San Marcos Muni Airport 75 94 76 90 / 10 40 30 60
La Grange - Fayette Regional 76 93 75 91 / 10 60 30 60
San Antonio Intl Airport 77 93 77 91 / 10 30 40 60
Stinson Muni Airport 77 95 78 93 / 10 30 30 50
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Short-Term...29
Long-Term...Brady
Aviation...04
Area Forecast Discussion
National Weather Service Grand Forks ND
1004 PM CDT Sun Aug 28 2022
.UPDATE...
Issued at 1002 PM CDT Sun Aug 28 2022
Severe threat has ended. Initial trough/dew point front has
cleared the area. Winds behind this trough briefly go west and
then go near calm until you get farther west ijnto DVL/JMS area
where west winds are higher closer to the upper low. Clouds south
of this upper low will spread into NE ND and far NW MN overnight.
Kept a few showers in the fcst for NE ND overnight but radars show
much less coverage after sunset.
UPDATE Issued at 647 PM CDT Sun Aug 28 2022
500 mb low in SW Manitoba with a well defined upper level short
wave trough moving through west central/northwestern MN. This is
ahead of the actual surface cold front/dew point line which is
in the Red River valley from west of Roseau to near Crookston to
Fargo then into far eastern SD. Frontal boundary showing up on
radar well but without upper level support having a very hard time
getting anything going. Thus the main severe threat to remain more
tied to the short wave trough aloft and its passage which is
likely going to east of the fcst area by 03z.
&&
.SHORT TERM...(This evening through Monday night)
Issued at 207 PM CDT Sun Aug 28 2022
The main hazards in the short term are the potential for severe
storms late this afternoon and early evening, and gusty northwest
winds Monday.
At mid afternoon, the surface pattern was still pretty messy.
Winds were still from many different directions within the Red
River Valley, with the steadier west-northwest winds from
Jamestown to western Pembina County. This is where dewpoints go
from the upper 60s to the 50s and below. Showers and storms
continue to form/die north of the F-M area and east of Grand
Forks. The associated upstream wave shows up nicely on water
vapor imagery, over northwest North Dakota and southeast
Saskatchewan. A nice cumulus field and additional showers and
storms have formed around it. There continues to be quite a bit of
stratus/low clouds and convective debris clouds across the FA.
There was some sun this morning over the Lake of the Woods region
and there is some now between Jamestown and Aberdeen, where
SBCAPE values are around 2500J/kg. However, there is still quite a
bit of MLCIN over the FA, and 700mb temperatures are in the +10C
range along/south of the Interstate 94 corridor. Finally, low
level lapse rates remain paltry across the FA from the morning
stratus. However mid level lapse rates are good, especially
along/south of the Interstate 94 corridor.
As the cold front takes better shape and pushes east of the Red
River Valley in the 3 pm to 8 pm time frame, additional storm
development is anticipated. The HREF UH tracks start to pick up
then, and continue through the early evening. The SREF calibrated
severe thunderstorm product also highlights this time frame. CAMs
have been less helpful, with the latest HRRR continuing to back
off on its initiation time to closer to 6 or 7 pm. So although
confidence may not be as good as would be preferred, still think
the earlier mentioned 3 to 8 pm time frame is the period when
storms may fire, mainly east of the Red River Valley. These storms
should be fairly quick moving, so after they shift east of the FA
by mid evening, the rest of the night should be precipitation
free. Behind the front on Monday, it looks pretty windy, with
steady northwest winds. It will be cooler and much drier as well.
.LONG TERM...(Tuesday through Sunday)
Issued at 207 PM CDT Sun Aug 28 2022
No major impacts are expected in the long term period. Large scale
ridging should keep ups quiet through the majority of the long term
period. As the week progresses, expect a very slow warmup in
temperatures, with highs reaching the 80s throughout the week. No
significant precipitation impacts are anticipated through the long
term period.
Towards the end of the period, ensemble guidance does still hint at
some deviations in the upper flow pattern, bringing the possibility
of impacts next weekend, although confidence is too low to make any
determinations.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 647 PM CDT Sun Aug 28 2022
Showers and thunderstorms with MVFR and IFR vsbys and cigs through
early evening but improving conditions late evening and overnight
to VFR conditions. Otherwise clear to partly cloudy sky in E ND
and RRV will last into the overnight with the exception of
stratocu which will move east into NE ND overnight and likely a
period of MVFR cigs in stratocu in cold advection over parts of
the nrn RRV and NW MN Monday. Gusty winds Monday 25-35 kts from
the Northwest.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...None.
MN...None.
&&
$$
UPDATE...Riddle
SHORT TERM...Godon
LONG TERM...Perroux
AVIATION...Riddle
Area Forecast Discussion
National Weather Service Goodland KS
523 PM MDT Sun Aug 28 2022
.SHORT TERM...(This evening through Tuesday night)
Issued at 210 PM MDT Sun Aug 28 2022
At the beginning of the short term period, the latest RAP analysis
shows the CWA with a west-southwesterly flow aloft with an upper air
low to the north on the Canada/U.S. border by ND with a weak trough
over UT. Current satellite imagery and surface obs show mostly sunny
skies with some clouds developing in southern Sherman and Thomas
counties along an surface convergence boundary. Models show the weak
trough moving eastward into the evening hours with a shortwave
disturbance moving through the flow over the CWA as well. At the
surface, isolated and short-lived light showers may form along the
convergence boundary this afternoon and that the area has reached
its convective temperature. Dry downbursts may be possible too here
with DCAPE values around 1600 J/kg and high low level lapse rates.
Later this evening, areas north of I-70 particularly in the
northeastern quadrant of the CWA may see a slight chance for
isolated light showers and thunderstorms as well ahead of an
approaching cold front. Severe weather is not expected as
convective parameters do not look supportive. Any precipitation
chances seen look to end before midnight with not much moisture
expected. Near record to record daytime highs between the lower
90s and middle 100s are expected with overnight lows in the middle
50s to middle 60s.
On Monday, model guidance shows the upper air low on the border
moving eastward with a large ridge moving over the western CONUS
including the CWA throughout the day. At the surface, an early
morning weak cold front is expected to pass through the region
bringing some slight relief compared to the previous day. Dry
conditions are expected for the CWA as well with better
precipitation chances staying southeast of the CWA. Monday`s daytime
high temperatures range from the middle 80s to the lower 90s while
overnight lows will be in the middle 50s to lower 60s.
For Tuesday, models show CWA continuing to remain underneath the
aforementioned large ridge throughout the entire day. At the
surface, dry conditions continue for the CWA under sunny skies
during the day with southeasterly winds around 5 to 15 kts. Expected
temperatures on Tuesday include daytime highs in the upper 80s to
middle 90s and overnight lows in the upper 50s to lower 60s.
.LONG TERM...(Wednesday through Sunday)
Issued at 1246 PM MDT Sun Aug 28 2022
Dry and warm are the conditions we can expect in the long-term. An
upper-level ridge over the Great Basin on Wednesday will work its
way east and influence the Tri-State area through the weekend. We
can expect a northwesterly flow from this setup that will weaken
throughout the forecasted period. Chances for rain are slim, but
pop-up showers could form in the afternoon and evening hours,
primarily on Wednesday near the Tri-State border. High
temperatures will be in the upper 80s to mid 90s with overnight
lows in the mid 50s to low 60s.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 519 PM MDT Sun Aug 28 2022
For KGLD & KMCK... VFR conditions are expected though pulse
thunderstorms are in the area. These thunderstorms are popping up
across the area and lasting for around 15 mins before dissipating.
The storms have also produced outflow up to 30 kts so that will be
another area of caution. Storms should stop forming later in the
evening with near zero chances after 06Z. Winds will shift to be
more northerly for the remainder of the period.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...076
LONG TERM...CA
AVIATION...KAK
Area Forecast Discussion
National Weather Service Grand Rapids MI
744 PM EDT Sun Aug 28 2022
LATEST UPDATE...
Aviation
.DISCUSSION...(This evening through next Sunday)
Issued at 212 PM EDT Sun Aug 28 2022
--Damaging winds and locally heavy rainfall possible ---
Showers and storms remain possible this afternoon and through the
overnight period with several lines of showers and storms
possible. Currently the showers and storms are north of Grand
Rapids. However as the warm front continues to move into the
region the moist southern flow will feed daytime afternoon
convection forming along a surface boundary.
Current storms that formed began fairly weak with sounding
showing low level lapse rates, in the 6 to 7C range. There
remains weak rotation as there is some low level shear. There is
some dry air aloft which will aid in downburst potential. The
HRRR did a poor job showing sfc dew points, which it then
inferred a larger low level capping inversion. The NAM nest is
doing a better job representing sfc dews with only a small cap and
decent amounts of CAPE. This is indicative of sfc convection
forming in northern Kent and Newaygo county this afternoon.
There remain some question on timing and formation tonight. Mesoanalysis
has decent DCAPES this evening which again shows the potential
for damaging downbursts. The biggest threats remain damaging
winds from downbursts and localized flooding from heavy rain. The
juxtaposition is that there will be better shear through the mid
levels as storms move further east, yet weaker instability.
A mid level trough that is swinging the LLJ will swing through
between 06Z to 12Z.
PWATS of 1.5 to 1.75 inches across the Great Lakes will fuel the
moisture. This coupled with the warm rain processes will allow for
heavy downpours that could cause ponding on roadways and
localized flooding. We are outlooked for a marginal risk of
excessive rainfall with spots of 1 to 2 inches of rainfall
expected with locally heavy rainfall in thunderstorms possible.
Best timing form storms will be from 00Z to 06Z though lingering
storms through the north could continue through the early morning
hours. Latest HREF has 850mb Jet at 35 to 40kts so given the
shear, it could allow for sustaining convection through Central
Michigan. SPC has the western portion of SW Michigan in a marginal
risk of severe storms.
--Another round of storms tomorrow evening--
As the upper level low moves through the Great Lakes region it
will bring a frontal system through the area. There remains the
possibility that as this convection develops given the shear and
sfc instability that severe remains possible late tomorrow aftn
into tomorrow evening. Low LCL`s with 3K J/kg of CAPE or more will
will make strong thunderstorms possible along the I 94 corridor.
SPC has a slight risk through this region
The cold front will exit Monday night into Tuesday. Daytime
Tuesday will be cooler and less humid and that will continue
through mid week. Temperatures will begin to warm again by the end
of the week as the high over the Great Lakes moves east.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 743 PM EDT Sun Aug 28 2022
A line of showers and thunderstorms will be moving into western
Lower Michigan this evening with the potential for areas of MVFR
and brief IFR conditions in heavy rain. Hail and wind gusts over
40 knots are possible with the stronger storms. The best chance of
this happening will be at MKG and GRR with more uncertainty
further east and south as the storms could weaken as they move
east.
Some ceilings in 2500 to 3500 feet AGL range will linger in th
wake of the storms. Another round of thunderstorms is possible
Monday afternoon with areas of MVFR and brief IFR conditions. Once
again, hail and wind gusts over 40 knots can be expected with the
stronger storms.
&&
.MARINE...
Issued at 1144 AM EDT Sun Aug 28 2022
Southwesterly flow continues to stream across the lake which is
causing moderate waves at Grand Haven northward, especially at
the points. The winds will continue to shift in that direction and
build overnight into tomorrow.
The southwesterly flow will continue to build through tomorrow,
though the convection will disrupt the flow, though bringing
hazards of their own. So due to these building waves and the
likeliness of several rounds of convection tonight through
tomorrow, conditions will be hazardous for boaters and for
swimmers by mid evening and through tomorrow.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...Beach Hazards Statement through Monday evening for MIZ037-043-
050-056-064-071.
LM...Small Craft Advisory until 11 PM EDT Monday for LMZ844>849.
&&
$$
DISCUSSION...Ceru
AVIATION...Ostuno
MARINE...Ceru
Area Forecast Discussion
National Weather Service Indianapolis IN
1129 PM EDT Sun Aug 28 2022
...Updated Aviation Discussion...
.Forecast Update...
Issued at 943 PM EDT Sun Aug 28 2022
Surface analysis this evening shows southerly flow in place over
Central Indiana due to high pressure in place east of New England
and low pressure over MN along with a cold front that stretched SW
to NB and western KS. Water vapor imagery shows a plume of moisture
stretching from the middle Mississippi Valley across IL to the Great
Lakes. This plume was entering Indiana. GOES16 also shows cooling
tops with recent convective development over SE IL.
Thunderstorms over SE IL are expected to continue to drift northeast
through the Wabash valley over the next several hours as a warm and
humid air mass remains in place. HRRR shows this development staying
mainly across the western half of Central Indiana…pushing NNE within
the flow aloft. Thus have trended toward high pops in the Wabash
valley the next several hours as the storms pass with chances
elsewhere later overnight as the plume of moisture aloft arrives
within the area. Forecast soundings overnight show a trend toward
deeper saturation as the plume arrives and this along with the
southerly flow in place will make for a warm night with lows in the
lower 70s. Ongoing forecast needed only minor adjustments in that
regard.
&&
.Short Term...(This Evening through Monday night)
Issued at 252 PM EDT Sun Aug 28 2022
Highlights:
* Increasing risk for showers and storms through Monday Night
* Growing potential for severe weather Monday afternoon and evening
Hottest afternoon in three weeks ongoing across central Indiana as
most of the forecast area has warmed into the upper 80s and lower
90s as of 18Z. Dewpoints in the upper 60s and lower 70s are adding
to the discomfort with heat indices in the mid and upper 90s common.
The upper ridge that had been across the Ohio Valley the last few
days has shifted off to the east...already being impacted by a
potent upper level low tracking along the U S-Canadian border over
the northern Plains this afternoon. This feature will be a key player
in the pattern shifting over the region as it tracks east into
Ontario through Monday night and pulls down an amplified trough over
the Great Lakes and Ohio Valley. Initially...lack of more
substantial moisture will limit convection this afternoon and
evening but growing signals at robust convective clusters to impact
the region Monday into Monday night ahead of a southward moving cold
front. The details with respect to how the convection evolves over
the next 30 hours or so and whether its in two main clusters or one
dominant cluster with scattered storms ahead of that remain
uncertain. But greater confidence now in potential higher impact
convection for parts of central Indiana...especially Monday
afternoon and evening.
An initial wave aloft approaching the region this afternoon should
eventually provide enough forcing to generate isolated convection
over the next few hours. Current satellite already showing some
agitation in the cu field and a few small showers as surface
temperatures have neared the convective temps. A deeper layer of
warm...dry air in the mid levels remains an inhibiting factor to
this point in seeing any convection initiate but should see the
thermodynamic structure of the atmosphere improve slightly later
this afternoon and into the evening as the upper wave approaches and
subtle cooling aloft takes place. Do not see much more than isolated
to widely scattered convection through early evening with the
potential for a small area of greater storm coverage impacting
northwest counties through the evening as the initial wave aloft
passes and interacts with briefly increased 850mb flow. LAPs
soundings currently show a well mixed boundary layer up to the 750-
700mb layer with steep lapse rates...which would suggest that any
elevated core that can organize would potentially carry a risk for
stronger winds as the updraft collapses. In general though...expect
any convection into the evening hours to remain subsevere with
little BL shear present and the remnants of the warmer layer in the
mid levels still in place.
Cannot rule out a few showers or storms overnight into early
MOnday...but should remain isolated to scattered at best with the
loss of the forcing aloft with the lead upper wave and weak
instability at best. Of much more interest to how Monday will play
out will be with the convective complex set to develop tonight
immediately ahead of the main upper low over the upper Midwest. The
cluster is likely to ride southeast into the western Great Lakes
Monday morning before diminishing as it approaches with the
weakening of the nocturnal low level jet.
This would be the point where the forecast could go a couple
different ways. One possibility would be that the remnant boundary
associated with the convective complex drifts into the area Monday
afternoon...interacts with the moist and highly unstable airmass
over the Ohio Valley and generates renewed convection ahead of the
potential for a second storm cluster developing along the cold front
to our northwest and dropping into the forecast area Monday evening.
The second scenario would be the first cluster dropping further
southeast into the region before weakening...leaving an abundance of
cloud debris which would stunt and disrupt heating and subsequently
make the potential lower for more widespread and robust convective
development later in the day into Monday evening.
At this point...leaning a bit more towards scenario one presented
above considering the increase in BL shear and a noted axis of
strong instability and deep moisture pooling ahead of the front.
Even if cloud cover is a bit more extensive than realized...expect
organized convection to fire late day into the evening along the
frontal boundary dropping into the area from the north. The amount
of instability that can be realized will determine if we see a
convective cluster than can generate a forward propagating cold pool
to drive severe weather into the region with a broader damaging wind
risk...or if severe storms are more scattered in coverage and
intensity. Still a fair amount of uncertainty that will likely not
be fully cleared up until early Monday...but the take away message
is that the potential for a higher severe weather threat late Monday
afternoon into Monday evening is present and growing. Stay tuned.
Even as the severe threat diminishes late evening Monday...numerous
showers and storms will continue throughout the night as the front
presses through the region and interacts with stronger boundary
layer flow. Rain should gradually taper off from the north towards
daybreak Tuesday.
Temps...Monday highs will be fully dependent on whether cloud debris
from the overnight MCS to our northwest is more extensive into our
area. With the more optimistic approach discussed above as the
complex weakens and leftover high clouds thin out on Monday...nudged
highs up a couple degrees from the previous forecast into the upper
80s. Lows tonight will largely stay at or above 70 with upper 60s to
lower 70s Monday night.
&&
.Long Term...(Tuesday through Sunday)
Issued at 252 PM EDT Sun Aug 28 2022
Tuesday and Tuesday night...
A cold front will be in the process of moving out early in the
period. CAMs continue to suggest that an MCS moving through late
Monday could provide mesoscale subsidence early Tuesday. Due to
this, rain chances will be limited ahead of the front. Isolated
showers cannot be ruled with lingering moisture and modest forcing,
mainly across far SE counties. Rain chances quickly taper off by the
afternoon as NW flow behind the front advects drier cooler air into
central Indiana. Surface high pressure begins to build in overnight
Tuesday, allowing for a quiet cool summer night.
While the cold front is expected to move through early in the day,
plentiful sunshine during peak heating should warm temperatures into
the mid 80s. Meanwhile, cold air advection will likely lead to below
average temperatures in the upper 50s overnight.
Wednesday through Sunday...
Through the remainder of the long term period, an upper trough
across the northeast and an upper ridge out west will result in
predominantly NW flow. In addition, guidance is in good agreement
that surface high pressure dominates mid to late week. Large scale
subsidence and NW flow will provide dry and pleasant weather,
especially late week with dewpoints possibly falling into the low
50s.
By the weekend, temperatures are expected to warm up as upper
ridging builds in. During this time, winds should become more
southerly with the surface high moving east of the area. Increasing
moisture due to southerly flow and daytime heating may lead to a few
isolated showers and storms on Sunday.
&&
.Aviation...(06Z TAF Issuance)
Issued at 1126 PM EDT Sun Aug 28 2022
Impacts:
* VFR conditions expected overnight and much of Monday.
* Low confidence in specific location/timing of convective evolution
for Monday.
Discussion:
A wave of convection over western central Indiana is expected to
continue to weaken over the next few hours as it propagates north
northeast. This will produce some brief IFR conditions at LAF just
before 06Z...but conditions are expected to rapidly improve to VFR in
the wake of the showers departing northeast.
Winds will remain around 10 knts overnight, providing mixing and
preventing fog development.
A trough of low pressure over the upper midwest will continue to
edge eastward and keep Central Indiana within the warm sector on
Monday. Forecast soundings suggest attainable convective temperatures
with a trend towards saturation within the column on Monday. Thus
convection will be expected to develop on Monday but this remains
low confidence regarding specific timing and locations. Best chances
should be during peak heating hours of the afternoon.
Thus have used a large window of VCTS through the day with mentions
for prevailing rain showers during Monday afternoon and evening.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Update...Puma
Short Term...Ryan
Long Term...Melo
Aviation...Puma
Area Forecast Discussion
National Weather Service New Orleans LA
922 PM CDT Sun Aug 28 2022
...EVENING UPDATE...
Overall, afternoon forecast package appears to be on track. Will
send an updated ZFP at some point in the next hour or so to remove
evening mention of precipitation as the last couple of showers
dissipate. Evening soundings continue to show a rather moist
airmass with precipitable water values in the 2.0-2.1 range.
Wouldn`t be surprised if moisture content down around Houma is a
little higher after the surge of showers/storms there around
sunset. Other than the point noted above, no signficant changes to
ongoing forecast. 35
&&
.PREV DISCUSSION... /issued 349 PM CDT Sun Aug 28 2022/
SHORT TERM (Today through Tuesday Night)...
Starting out with late this afternoon and going into this
evening, radar trends continue to illustrate widely scattered
showers and a few storms across the area. As discussed in the
morning update, we have seen a very slight lowering in overall
total PW`s today, ranging around 1.9" to 2.0" with the 12Z KLIX
RAOB illustrating somewhat of a "drier" profile compared to
previous days (especially in the H5 to H3 layer). This has helped
reduce coverage a notch, but higher PW moisture surge will
continue to filter north across SE LA and S MS this evening mainly
across areas west of I-55 where PoPs are greatest, but any
lingering showers will dissipate around or shortly after sunset.
Starting out the new work week with some patchy fog possible
across SW MS and maybe as far as around Baton Rouge daybreak.
However, coverage and density will be dependent on if locations
saw rain this evening enough to saturate the grounds in helping
fog production/maintenance. Elsewhere things will be quiet to
start the day with high pressure remaining in control of the
eastern US, helping to continue to pump deep gulf moisture north
over the MS River Valley ahead of an ESE surging cold front
across the Plains/Midwestern states. Worthy to point out looking
at GOES-16 IR currently is a blow up of convection in the western
Gulf. This is in conjunction with weak closed mid-level low and
associated vorticity. This little system eventually becomes
stretched out meridinonally and pulled north into eastern
TX/western LA thru the day on Monday, helping to surge much higher
PW`s north along with it into the area. What this in turn means
for us is another uptick in shower/storm coverage primarily from
late morning through early evening, with greatest coverage
potential for areas west of I-55 closer to deeper moisture/higher
PW`s around 2.2-2.4". With deeper sfc to low-level flow in place
across western areas within the periphery of deeper moisture
fetch, mean storm motion averages around 5-7kts out of the SSW.
Could likely see some northward surging band of storms as the
recent 12Z HRRR depicts, with good news being propagation would
hopefully alleviate flash flooding concerns. However, more towards
areas east of I-55, mean storm motion is very slow with less of
an overall southerly flow in place giving nearly 0-2kt mean storm
flow. Outside of bands towards the west, storms could easily pop
up and sit over the same areas and lead to flash flooding,
especially in and around complex boundary interactions.
Going into Tuesday, the same subtle mid-level disturbance
continues to weaken over southern or southwestern LA reflected by
remnant mid-level vorticity. This, in conjunction with the same
enhancement of PWs anchored in place will bring another round of
more widespread storms, similar to Monday. The wind field aloft
remains very weak, with mean storm flow to a crawl and given
2.1-2.3" PW`s and the dynamic enhancement from remnant mid-level
vorticity, intense rain rates may lead to some flash flooding
concerns. Not seeing any strong indications of widespread issues
just yet, but will continue to be monitored. Also, weak vertical
winds will continue to be favoritable for weak waterspouts
over coastal or marine areas both Monday and Tuesday mornings.
KLG
LONG TERM (Wednesday through Saturday)...
Mid-week, we continue to see a shift in the overall mid-level
flow pattern with a progressive/amplifying east coast trough
taking shape, and deep ridging building over the western US. This
helps to surge the same front mentioned to our north over the
Midwest, south and east with time eventually trying to make its
way to the northern Gulf coast. Recent 12Z run has come in a bit
aggressive pulling the front well down into the coast, trying to
reveal upper 50 dewpoints into southwestern MS. Before you (or I)
get too excited, this is an outlier in trends and appears to be
supported by the idea that there will be a subtle shortwave
building southeast along northwesterly flow, in an attempt to give
it a second "boost" through here. This is a bit of a hard sell,
especially given how fronts are absolutely difficult to get
through our area. But, having said that, even if the front tracks
close enough, there could be a bleed over of dry mid-level air,
perhaps low enough to help attain strong PBL mixing and knock
dewpoints down some. Additionally, that same mid-level dry air
would lead to entrainment in any diurnally (and frontal) forced
storms to lead to a damaging wind risk. Something to watch for
now.
Will briefly touch on the tropics as things could heat up a tad
in the long range (5-7 day frame). Long-range trends have been
consistent developing a system in the NW Caribbean or southern
Gulf. Question remains how the same front and sfc high building
behind could play a factor in the future position, as models
confidently keep the system more to the south, rooted in the
easterlies by cutting across the Yucatan Peninsula and into the
Bay of Campeche. Way too many variables to filter through
scenarios, as there are so many intricate details that will play a
big factor in the future strength and position of the system.
Will refrain from diving deep here, but given the time of the year
as we approach the climatological peak of hurricane season,
everyone should keep an eye on future forecast updates. KLG
AVIATION (18Z TAF DISCUSSION)...
Recent radar trends illustrate scattered SHRA/some TSRA developing
across the area. Expect coverage to continue to increase, with
more widespread development for terminals along and west of I-55
and across the Southshore. Main impacts will be periodic
reductions in VIS and CIG leading to temporary reduction in flight
categories along with gusty downdraft winds in excess of 20 to 30
knots. Otherwise, any lingering activity will steadily diminish
after 23-01Z revealing calm conditions tonight. Will have to
monitor for the potential of patchy fog across KMCB around
daybreak Monday, with the possibility of flight category
reductions to IFR/LIFR going into 12-13Z Monday. KLG
MARINE...
High pressure dominating the eastern US will continue to promote
southerly to southeasterly onshore flow through this week, with
daily (mainly morning) showers and thunderstorms. Main threats
with any stronger to severe storm will be wind gusts >34kts,
waterspouts and locally enhanced waves/seas. Otherwise, winds an
waves/seas will be calm outside of any thunderstorm activity. Late
this week, there are some indications of steady rises in offshore
waves/seas reaching 4 to 6ft for outer 20-60nm zones as easterly
to east-southeasterly fetch increases, but being this far out,
confidence remains low at this time in regards to potential
impacts. KLG
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 72 88 72 88 / 30 70 20 80
BTR 75 90 75 91 / 40 80 20 80
ASD 75 91 75 93 / 10 60 10 70
MSY 77 89 78 90 / 20 60 10 70
GPT 75 90 76 91 / 10 50 10 60
PQL 73 90 74 91 / 10 40 10 60
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...None.
GM...None.
MS...None.
GM...None.
&&
$$
Area Forecast Discussion
National Weather Service Spokane WA
802 PM PDT Sun Aug 28 2022
.SYNOPSIS...
A significant warming trend early to mid week will bring
temperatures back into the 90s with the hottest locations close to
the triple digits by Wednesday. There is a small chances for
showers and thunderstorms to develop across the mountains
Wednesday afternoon. A weather system late in the week may usher
in cooler temperatures again along with breezy winds.
&&
.DISCUSSION...Update: Added areas of smoke in Okanogan and Ferry
county as latest HRRR suggests smoke from a fire in Eastern
Whatcom county which might be named the Brush Creek fire which
became quite active this afternoon and generated a substantial
smoke plume that drifted east/southeast and is expected to
continue to drift east tonight into early tomorrow morning before
being displaced northward into southern British Columbia. /Pelatti
&&
.AVIATION...
00z TAFs: VFR will continue through the TAF period. Winds will
mostly be light southwesterly this afternoon before becoming light
and variable tonight. Light easterly or northeasterly winds are
expected to develop by Monday morning in far eastern Washington
and the Idaho Panhandle, with terrain driven winds in the lee of
the Cascades.
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 53 87 57 94 59 97 / 0 0 0 0 0 0
Coeur d`Alene 50 85 56 93 57 96 / 0 0 0 0 0 0
Pullman 47 86 51 95 55 95 / 0 0 0 0 0 0
Lewiston 56 92 61 99 65 102 / 0 0 0 0 0 0
Colville 44 87 48 94 52 96 / 0 0 0 0 0 0
Sandpoint 47 82 51 91 54 93 / 0 0 0 0 0 0
Kellogg 55 83 60 90 63 94 / 0 0 0 0 0 0
Moses Lake 53 90 57 98 62 99 / 0 0 0 0 0 20
Wenatchee 60 90 66 96 69 99 / 0 0 0 0 0 10
Omak 56 91 61 98 64 100 / 0 0 0 0 0 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
Area Forecast Discussion
National Weather Service Pueblo CO
355 PM MDT Sun Aug 28 2022
.SHORT TERM...(This evening through Monday)
Issued at 355 PM MDT Sun Aug 28 2022
Key Messages:
1) Scattered showers and isolated thunderstorms across the higher
terrain, mountain valleys, and the I-25 corridor through early to
mid evening. Strong winds of 45 to 55 mph will remain possible.
Westerly flow has ushered in some more defined mid level energy
across the region and while drier air is in place, have seen showers
and thunderstorms really blossom this afternoon. This large scale
ascent, low level convergence, and additional focus now along
several outflow boundaries will allow for additional development
through early to mid evening. From this point forward, now expect
the highest coverage to be along and south of Highway 50 over the
higher terrain, mountain valleys, and I-25 corridor. The drier air
should limit the extent of the heavy downpours and any flash flood
risk, however, brief heavy downpours will remain possible. Given the
dry air in place and high DCAPE noted on latest RAP analysis, think
strong winds of 45 to 55 mph will remain possible. While the
potential for any winds stronger, possibly up to 60 mph, appears to
be low, can`t completely rule it out at this time. Precip diminishes
this evening, with drier conditions then expected through the period.
.LONG TERM...(Monday night through Sunday)
Issued at 355 PM MDT Sun Aug 28 2022
Monday night-Tuesday night...Latest models continue to indicate
an elongated upper ridge in place across the Great Basin and into
the Central Rockies through the day on Tuesday, though have come
into better agreement with a slight increase in available moisture
moving northward into southwestern Colorado underneath said ridge.
This will keep isolated showers and storms across the Southern
Mountains and along the Southern Tier early Monday evening, before
convection wanes Monday night, with isolated to scattered showers
and storms expected over the higher terrain Tuesday afternoon and
evening, greatest coverage across the ContDvd. With warm air aloft
under the ridge, highs to remain above seasonal levels in the 80s
to lower 90s across the plains, and mainly in the 60s and 70s,
with lows around seasonal levels mainly in the 50s across the
plains and generally in the 30s and 40s across the higher terrain.
Wednesday-Friday...Latest model data continues to indicate the
upper ridge sliding south and west of the region, as short wave
energy translates down the backside of the ridge across the
Northern Rockies and into the High Plains. This, along with a weak
associated front moving across the eastern plains on Wednesday,
will lead to a slight uptick in shower and storm active Wednesday
afternoon and evening over and near the higher terrain, with a few
possible storms moving across the I-25 Corridor. There looks to
be enough recycled moisture to support more isolated convection
over and near the higher terrain Thursday and Friday afternoon and
evening, with the potential for a few storms across the Southern
Tier, just north of the stalled front. Despite the increase in
convection and weak front, model data supports temperatures remaining
at to slightly above seasonal levels through this period.
Saturday-Sunday...Longer range models and ensemble data indicate the
elongated upper ridge building back across the Rockies into next
weekend, as more energy translates across the Northern Tier. Latest
operational models struggling where said Northern Tier energy moves
into early next week, however ensemble data suggests this energy
will remain north and east of the Central Rockies. At any rate,
there should be enough residual moisture to support generally
isolated diurnal mountain convection through the weekend, with
temperatures remaining at and above seasonal levels.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 355 PM MDT Sun Aug 28 2022
Isolated showers and thunderstorms will remain possible at all sites
through early evening, though the potential for any prevailing
thunder looks to be low at this time. Stronger winds will accompany
this precipitation, with westerly winds gusting to around 30 kt at
ALS and northerly winds gusting to around 35 kt at COS and PUB.
Winds will diminish later this evening, with VFR conditions with dry
weather then expected for the remainder of the period.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...RODRIGUEZ
LONG TERM...MW
AVIATION...RODRIGUEZ
Area Forecast Discussion...UPDATED
National Weather Service Springfield MO
931 PM CDT Sun Aug 28 2022
Key Messages:
1. Scattered showers and storms will continue to occur at times
into this evening for portions of the area mainly east of Highway
65. A few stronger storms will be possible with gusty winds the
main risk.
2. Better chances for rain will occur Monday and Monday night as
a front moves south through the region. Some strong to severe
storms will be possible with this activity Monday afternoon and
evening.
3. Weather looks dry with seasonable temperatures the rest of the
the week.
.MESOSCALE DISCUSSION...
Issued at 917 PM CDT Sun Aug 28 2022
Forecast largely remains on track with only some small precip
chance updates for the rest of the night. Early evening storms
have ended and the area was mainly rain free. Some high clouds
were streaming in from the Oklahoma thunderstorms. 00z SGF
sounding showed a moist and unstable airmass across the area with
3000j/kg of ML CAPE, only -7j/kg of inhibition and a precipitable
water value up to 1.85in. There was also the beginnings of a low
level jet with 30kts winds measured around 850mb.
Looking at water vapor imagery, a strong shortwave can be see
across the northern US, with a weak flow and small embedded
vortices across the Kansas/Oklahoma/Missouri region. Therefore no
large scale lift is present, which should limit thunderstorm
development overnight. What we do expect is for the low level jet
and warm air advection to continue to increase some overnight, and
is typical in this regime, isolated showers and thunderstorms
develop on the eastern periphery of this. A look at current and previous
high res model runs shows decent consensus that isolated showers
and storms may form after 3am across southern Missouri or
northeast OK/northwest AR and move into the area. Lightning and
heavy rainfall are the main threats.
The eventual progression of these morning storms will have an
influence on how other storms play out tomorrow with the 00z HRRR
increasing storm coverage and strength from mid morning onward.
Given the instability already in place, this seems plausible.
&&
.SHORT TERM...(This evening through Monday night)
Issued at 338 PM CDT Sun Aug 28 2022
An upper level shortwave is moving through the area currently.
Scattered storms have developed ahead of the trough. Scattered
showers and storms will continue to develop and move east across
portions of the eastern Ozarks this afternoon into this evening. A
few stronger storms will be possible with gusty winds the main
risk. Frequent lightning and brief heavy down pours will also
occur with the stronger storms.
An upper level trough will continue to move east across the
northern Plains today then into the Great Lakes region on Monday.
Elevated storms will be possible tonight into Monday as
instability increases and the cap weakens with a storm lifted
above 800mb. There will be lift with associated with the upper
level trough to make some isolated to scattered storm possible
tonight into Monday morning. No severe weather is expected
tonight.
As the upper level trough moves east on Monday a front will move
south towards the area. Additional storms will develop along the
front Monday afternoon and evening. Storm area expected to
develop along the front and move south into the area Monday
afternoon/evening.
Instability will increase across the area on Monday, but shear
will be more marginally across the area as the trough axis remains
north of the area. The better upper level support remaining north
of the area will limit the widespread severe risk, but with the
amount of instability in place and strong theta-E differences
there will be the potential for some strong storms with a few
severe storms possible. Hail up to the size of quarters will be
possible mainly long and north of I-44 and wind gusts up to 60 mph
will be the main risk. Frequent lightning and localized heavy
down pours will also occur with the storms.
A line of storms could develop by Monday evening and dive south
across the area into Monday night. As the decent Theta-E
differences could allow a strong cold pool to develop and low
level shear would favor a southern moving line to maintain moving
south across a good potion of the area. Though the shear weakens
the further south closer to the Arkansas boarder and with better
instability and upper level support to the north the line of
storms should weaken as it moves across and out of far southern
Missouri. So, coverage could decrease some from north to south
Monday night. Some linger showers/storms could occur Tuesday
morning but most of the activity should move south of the area
fairly quickly Tuesday morning.
.LONG TERM...(Tuesday through Sunday)
Issued at 338 PM CDT Sun Aug 28 2022
The models and ensemble members are then in pretty good agreement
that surface high pressure will move into the area for much of
next week. Which will keep the area mainly dry with seasonable
temperatures. Highs will be in the 80s to near 90 with lows in
the 60s occur each day through the week.
&&
.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 548 PM CDT Sun Aug 28 2022
The chance for an isolated storm this evening remains very low
(less than 20%) and left out of the TAFs for now. Slightly higher
chances start back at the sites as early as 09z and continue off
and on through the morning. Additional storms are possible by
afternoon and evening Monday. Winds will remain steady out of the
south around 10kts with gusts around 20kts at JLN this evening.
VFR ceilings are likely outside of any storm.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
MESOSCALE...Burchfield
SHORT TERM...Wise
LONG TERM...Wise
AVIATION...Burchfield
Area Forecast Discussion
National Weather Service Tulsa OK
747 PM CDT Sun Aug 28 2022
...New SHORT TERM...
.SHORT TERM...
(The rest of tonight)
Issued at 726 PM CDT Sun Aug 28 2022
Storms across eastern Oklahoma and west-central Arkansas have
starting to weaken this evening with loss of heating. Still
a chance for a few elevated thunderstorms to develop overnight as
upper jet streak approaches from the west. Looking at latest
radar trends, backing building/training storms may stay mainly
west of the area, similar to the 18Z NAM solution. Any storms
that can develop however will likely produce locally heavy
rainfall as PWATs stay around 2 inches. Update will be sent by 9
PM.
&&
.LONG TERM...
(Monday through Sunday)
Issued at 114 PM CDT Sun Aug 28 2022
Locally heavy rainfall potential will linger thru Monday morning,
though coverage should be low. The latest blended guidance has
backed off from the likely PoPs for Monday afternoon, with the
NAM again fairly sparse across our area and HRRR showing more
spotty coverage. As was mentioned yesterday, a frontal boundary
will still be to the north over KS during the afternoon, with
storms expected to focus along it. Some of this activity may drop
south into NE OK Monday evening. Storm chances will continue
Tuesday as the boundary moves south across the region, lowest
north highest south. Drier deep layer airmass behind the front
will bring tranquil weather for the remainder of the week. Low
rain/storm chances will return by next weekend as moisture returns
from the south.
Lacy
&&
.AVIATION...
(00Z TAFS)
Issued at 619 PM CDT Sun Aug 28 2022
Scattered thunderstorms ongoing generally near I-40 will wane
after sunset with little precip expected overnight. Few showers
possible Monday morning at northern sites with additional
thunderstorms possible Monday after 18z. WHile prevailing flight
conditions will remain VFR, any direct impact from stronger storms
will result in at least brief MVFR conditions. Like today,
uncertainty regarding specific locations and/or timing of impacts
remains high.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 76 94 73 93 / 20 40 30 20
FSM 76 93 74 95 / 10 30 30 30
MLC 74 92 71 93 / 10 30 30 40
BVO 72 94 68 93 / 20 40 40 20
FYV 72 88 66 91 / 20 30 30 20
BYV 73 88 69 91 / 20 40 30 20
MKO 73 91 71 92 / 20 30 30 30
MIO 73 91 69 92 / 20 40 40 20
F10 73 93 70 93 / 30 40 30 30
HHW 74 91 73 91 / 0 20 20 50
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...None.
AR...None.
&&
$$
SHORT TERM...12
LONG TERM....30
AVIATION...14
Area Forecast Discussion
National Weather Service Las Vegas NV
744 PM PDT Sun Aug 28 2022
.SYNOPSIS...Hot conditions will build over the region for the
upcoming week with temperatures becoming excessively hot by
Tuesday and persisting through the weekend. Thunderstorm activity
will cease for most areas this week...though some isolated
activity may return to Northwest Arizona by next weekend.
&&
.UPDATE...Generally quiet evening across the area, with just an
isolated storm north of Barstow. This should dissipate shortly with
the loss of daytime heating. The weather headlines this week shift
away from monsoon storms and towards late-summer heat as high
pressure builds this week. Temperatures will rise well-above normal,
prompting an Excessive Heat Watch from Tuesday through Sunday. We`ve
been treated to a stretch of "cool" and "wet" conditions, but that
is coming to an end (at least through the work week). Updated
forecast package will be out tonight.
&&
.SHORT TERM...through Monday night.
Subtle moisture push up the Colorado River Valley has resulted in
a slight uptick surface moisture across the region along with
slight surface cooling across the Mojave Desert and Colorado River
Valley. Some scattered cumulus has also begun forming across the
mountains of Clark, Lincoln, and Mohave counties through they lack
much vertical development. Still anticipate some very isolated
showers and a few lightning strikes developing from Northwest
Arizona westward towards the Mojave Preserve by late-afternoon.
Several successive runs of the HRRR have also suggested some
brief development as far west as Barstow, where some cumulus build
ups have already been noted near the San Bernardino and San
Gabriel mountains, so this still seems plausible, especially with
a vort max projected to be lifting into SoCal this evening.
Tomorrow, the thermodynamic details change little with some
lingering very low grade monsoonal moisture hanging around while
the region is sandwiched between a weak trough over central
California and a building ridge over the intermountain states.
This will result in similar temperatures tomorrow which should
average a couple degrees above normal, along with a few very
isolated, terrain driven showers possible, mainly in southern
Nevada and Northwest Arizona.
.LONG TERM...Tuesday through next weekend.
The heat is on as a strong ridge of high pressure builds across
the Great Basin and lingers through the weekend. Temperatures
will begin their upward climb on Tuesday and continue to rise into
Wednesday and Thursday. This will be the hottest stretch of
weather we`ve seen in more than a month across our forecast area,
so don`t let the calendar date fool you, as late summer heat can
be just as dangerous as early and mid summer heat waves. Given the
increasing confidence on a long duration heat episode, went ahead
and issued an Excessive Heat Watch for most of eastern
California, southern Nevada, and northwest Arizona for Tuesday
through Sunday. There is some potential for minor moisture
increases to offset the heat across the lower Colorado River
Valley and Northwest Arizona by the weekend, but confidence is
low in this possibility so for now, favored the heat persisting
area wide through the weekend.
For those weather lovers like me who have enjoyed the active
monsoon 2022 has brought us, it`s not over just yet! But it will
be taking an extended break as we head into the start of
September.
&&
.AVIATION...For Harry Reid...Southeast to south winds are
expected through the afternoon and into the evening. Wind speeds
will generally be 10-18 kts, but could occasionally gust to around
20 kts at times. Winds will diminish this evening and generally be
southwest around 7 kts. Light winds are expected Monday morning with
a general east to southeast wind expected by late morning into the
early afternoon. FEW100-120 through 03Z with clear skies overnight.
For the rest of southern Nevada, northwest Arizona and southeast
California...Most of the region will remain dry with tranquil
weather today except for isolated thunderstorms over the mountains
of northwest Arizona. General south-southwest winds sustained 8-18KT
can be expected today and tonight. Similar conditions are expected
on Monday.
&&
&&
.SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report
any significant weather or impacts according to standard operating
procedures.
&&
$$
UPDATE...Woods
DISCUSSION...Outler
AVIATION...Gorelow
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