Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 09/01/20
Area Forecast Discussion
National Weather Service La Crosse WI
1106 PM CDT Mon Aug 31 2020
.SHORT TERM...(This evening through Tuesday)
Issued at 300 PM CDT Mon Aug 31 2020
Forecast concerns in the short term will be extent of fog
tonight and low temperatures, then small chance for showers and
thunderstorms Tuesday.
Rainfall this morning was heaviest across parts of Dodge,
Olmsted, Winona, Houston, Wabasha, and La Crosse Counties where
some spots picked up 2 to 3 inches of rainfall. The highest
amounts were near Kasson with 2.8 inches in Olmsted County and 2.7
inches at Whitewater State Park in Winona County.
The 12Z MPX upper air sounding was moist to around 450mb with 1.51
inches of precipitable water. Instability was limited around 300
to 500 J/kg and 0-6km shear was 61kts. The most active
thunderstorms were pre-frontal, however with multiple rounds of
showers and storms, they did put down some decent rains.
The latest water vapor satellite imagery, visible satellite, radar,
and observations show the showers and thunderstorms have moved out
of the forecast area. The cold front has switched winds around to
the northwest and at 2pm was located near... A few cumulus are
filling in behind and the brisk northwest winds are ushering in
dewpoints in the 40s and 50s for this afternoon.
The shortwave trough is swinging through the Upper Peninsula of
Michigan with a 90kt jet at 300mb keeping the precipitation
progressive. Cirrus are already spreading across the Dakotas ahead
of the next shortwave over the Rockies. Surface high pressure will
build into the region tonight with winds becoming light and
variable. With the wet ground and light winds, attention turns to
potential fog formation. Some of the short range models highlight
the parts of western Wisconsin for fog Tuesday morning. With the
increasing clouds from the west overnight, this should help
mitigate the fog somewhat. Did go ahead and include some fog
mention for our western Wisconsin counties, but depending on the
cloud cover, this may have to be expanded.
Tuesday, the next shortwave trough will track across the Plains
and into the forecast area. Isentropic lift increases across the
forecast area with isolated showers possible. There is a hint at a
narrow band from Minnesota into Wisconsin and another potential
area from northeast Iowa into southwest Wisconsin. The northern
edge of the instability could make it into our area, so did
include isolated thunder mention. Lows tonight should mostly be in
the 40s, with a few warmer spots in the lower 50s. High Tuesday
will be cooler than normal in the lower to mid 70s.
.LONG TERM...(Tuesday night through Monday)
Issued at 300 PM CDT Mon Aug 31 2020
Westerly flow develops Wednesday ahead of the next approaching
shortwave. Warmer temperatures are forecast with highs from the
mid 70s to the mid 80s. The front pushes through Wednesday night
into Thursday morning. For now have the chance for isolated
showers and thunderstorms confined to north central Wisconsin.
Highs Thursday should be in the 70s to lower 80s.
The next cold front arrives Saturday night into Sunday and we have
chance showers/isolated thunderstorms included in the forecast.
Some of the extended forecasts have some colder temperature for
Sept 8th and 9th. This will be a period to watch out for related
to the potential for frost in frost favored areas.
&&
.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 1100 PM CDT Mon Aug 31 2020
High and mid clouds will move into the area overnight. These
clouds continue to provide some uncertainty on whether KLSE will
see dense fog overnight. In addition, the winds do not become
favorable until late. Meanwhile, the temperature and dew point
spread is around 6F which make it some what better for the
possibility of dense fog. To further complicate things the RAP
keep the boundary layer dry. Due to this uncertainty just went
with BCFG.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
IA...None.
&&
$$
SHORT TERM...Zapotocny
LONG TERM...Zapotocny
AVIATION...Boyne
Area Forecast Discussion
National Weather Service Dodge City KS
604 PM CDT Mon Aug 31 2020
...Updated Aviation Discussion...
.SHORT TERM...(This afternoon through Tuesday night)
Issued at 1200 PM CDT Mon Aug 31 2020
A refreshing preview of autumn, as noticeably cooler, and more
impressively, much drier air invades SW KS. It has been quite some
time since we have seen dewpoints fall well down into the 40s. The
cold front has cleared Barber county as of late morning. The
N/NE winds will continue to diminish quickly through this
afternoon as weak surface high pressure builds over Kansas.
Remaining stratus will also gradually dissolve this afternoon,
with comfortable afternoon temperatures in the 70s.
A strong shortwave diving into the Pacific NW/Idaho at midday,
will evolve into a weak closed low near Grand Junction Colorado
at sunrise Tuesday, then sink south into northern New Mexico
Tuesday evening. Diffluence aloft ahead of this digging shortwave
will supply synoptic lift over SW KS tonight through early
Tuesday, with increasing clouds expected. With easterly components
in the boundary layer and upslope flow, stratus is also expected
early Tuesday morning. The challenge revolves around shower
generation and precipitation chances with this system. Some models
including ECMWF and the latest extended HRRR iterations develop
scattered to even numerous showers during the morning/midday hours
Tuesday. 12z NAM is almost bone dry. 12z GFS offers a compromise
between these two extremes. Tried to take a middle ground approach
with low chance/scattered category pops in the grids late tonight
through midday Tuesday, but with the model disarray confidence is
not great. Instability will be very weak; kept isolated thunder
in the forecast, but would not be surprised if there was no
lightning at all. Lows tonight in the upper 50s and lower 60s with
light NE winds.
The mild temperatures will continue Tuesday, as the cool airmass
is maintained by light NE winds. Extra cloud cover and any showers
(favoring the southern counties/Oklahoma border nearest the New
Mexico upper low) will also work to keep temperatures below normal
for the first day of September. Again, even if the wetter model
solutions verify, instability will be nil to weak, and thunder
will be limited. Expect afternoon temperatures in the 70s for most
locales, with a few lower 80s where some partial sunshine can be
realized.
.LONG TERM...(Wednesday through Monday)
Issued at 155 PM CDT Mon Aug 31 2020
Long term will feature an extended period of typical late
summer/early autumn weather, with dry conditions prevailing and
mild/comfortable temperatures.
Weak closed midlevel cyclone near Clovis, New Mexico sunrise
Wednesday will drift eastward into West Texas daylight Wednesday.
The vast majority of rainfall with this system will remain south
of Kansas, but can`t rule out a few showers grazing the Oklahoma
border at times. Most locations will remain dry. With more
sunshine, Wednesday will be warmer with maximum temperatures
mainly in the lower to mid 80s.
High confidence another long stretch of dry weather is on the way
Thursday through Sunday. Strong high pressure aloft (596 dm) over
Nevada on Thursday, is progged by 12z ECMWF to remain stationary
over the Great Basin and strengthen to near 600 dm by Sunday.
Heights climb over SW KS through this time, with no forcing for
rainfall and few if any clouds. A weak dry cold front is expected
Thursday with little fanfare, just a northerly wind shift.
Afternoon temperatures in the 80s will be typical, as the core of
the upper high and its associated heat will remain well west of
Kansas. Long term models hint at a much stronger cold front early
next week, and this feature will likely provide the next
opportunity for widespread rainfall.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 602 PM CDT Mon Aug 31 2020
Clear skies and a northeasterly wind at less than 10 knots will
begin the night but the persistent east to northeasterly flow
overnight will bring low level moisture back into southwest Kansas
after 06z Tuesday. Based on the latest BUFR soundings this low
level moisture will lower ceilings into the IFR category after 09z
Tuesday and a period of LIFR conditions will be possible between
12z and at 17z Tuesday. Areas of fog and drizzle will also be
possible given the forecast depth of this low level moisture early
Tuesday morning. Ceilings will gradually improve late Tuesday
morning but given the depth of this low level moisture the clouds
will linger through most of the afternoon as an east to
northeasterly flow continues at 10 knots or less. There will also
be a chance for some widely scattered early morning convection.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 60 79 60 83 / 30 20 10 10
GCK 58 75 58 82 / 30 30 10 0
EHA 58 78 57 82 / 20 30 30 10
LBL 57 82 60 84 / 30 30 30 10
HYS 58 77 59 84 / 20 20 0 0
P28 65 83 64 82 / 30 30 20 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Turner
LONG TERM...Turner
AVIATION...Burgert
Area Forecast Discussion
National Weather Service Fort Worth TX
701 PM CDT Mon Aug 31 2020
.SHORT TERM... /NEW/
/Tonight through Tuesday Night/
Showers and thunderstorms have increased in coverage along a well
defined cold front extending from near Midland to Vernon to
Oklahoma City this evening. This activity should primarily remain
across our far northwest counties and across parts of Oklahoma
into the nighttime hours as mid level flow becomes a little more
southwesterly. This should keep most of North and Central Texas
precipitation free this evening. An axis of moderate instability
is present from near Wichita Falls eastward along the Red River
and across much of southern Oklahoma. To the south of this
instability axis, low level moisture is a little less, but a
strengthening low level jet should allow this to recover
overnight. For the remainder of tonight, we`ll have the highest
PoPs off to our northwest through midnight. The latest runs of the
HRRR actually keep the bulk of the convective activity across
Oklahoma overnight, but with low level warm advection becoming
maximized via the low level jet just north of I-20, I have to
think that some of this convection will tend to build southward
toward morning. So we`ll continue the trend of showing increasing
PoPs south of I-20 into early Tuesday morning.
There will likely be a break in the convective activity as this
initial complex weakens late tomorrow morning, but as an upstream
shortwave digs into West Texas late tomorrow, additional showers
and thunderstorms are expected to develop in the late
afternoon/evening and move across North Texas overnight.
Short term hazards...
Heat Advisory...
We`ll address the Heat Advisory which currently runs through
Tuesday evening across a good chunk of North and Central Texas. As
of now we`ll leave this unchanged, however, if it is more apparent
that convection will continue southward through the morning hours,
the northern portions of this advisory may be cancelled. To the
south, it will still be quite hot and humid with highs in the
mid/upper 90s and dewpoints in the mid 70s. Heat indices should
easily exceed 105 degrees.
Flooding Potential...
Given the potential for deep convection to become locked onto a
slow moving boundary overnight into Tuesday, the threat for
localized flash flooding is increasing. We`re already seeing
nearly stationary storm motion off to the northwest. With an
increasing low level jet overnight, the threat will quickly
increase across parts of the Red River Valley. There is some
potential for 3-6" of rain overnight with any storms that are slow
moving. We`ll issue a Flash Flood Watch for our Red River counties
and include Young/Jack/Wise for now. This is basically everywhere
north of the current Heat Advisory. This watch will also likely be
modified to some degree over the next 24 hours.
Severe Threat...
The severe threat will primarily be this evening and tonight with
convection tied to the front. Strong winds and hail will be the
main threats. This threat will transition into a hydrologic threat
late tonight through Tuesday.
Dunn
&&
.LONG TERM... /Issued 400 PM CDT Mon Aug 31 2020/
/Tuesday Night Through The Labor Day Weekend/
September is off to an active start as unsettled weather with
increasing rain chances and temperatures near or below average for
this time of year will punctuate the kick-off of meteorological
fall. There are no significant chances to the long term forecast
with this issuance. The best widespread rain chances continue to
be Tuesday night through Wednesday across North Texas with more
isolated/scattered activity across parts of Central and East
Texas. Rain chances linger through the week as additional rounds
of showers and thunderstorms remain possible into Labor Day
weekend.
An upper-level low will approach the Southern Plains from the
Desert Southwest on Tuesday with west-southwest mid-level flow
streaming across the state of Texas. Subtropical moisture
transported by this southwest oriented flow will prime the region
with precipitable water value in excess of 2", making heavy rain
possible through the period. At the surface, a cold front will
continue to move southward through the region late Tuesday and
Wednesday. This boundary in addition to any remnant outflow
boundaries lingering from the Monday night/Tuesday storms and
large scale lift from the approaching shortwave should be
sufficient for thunderstorms to develop across North and Central
Texas. As this activity continues to move southeast into better
moisture and instability, moderately deep layer shear may be
sufficient for damaging winds and strong updrafts capable of hail.
With ample moisture in place, all storms that develop will be
efficient rain producers, with heavy rain likely which may lead to
localized flash flooding issues and minor river flooding,
especially in areas that received rainfall in the past few days.
The heaviest rainfall is still forecast to fall along and north of
the I-20 corridor where a widespread 2 to 4 inches of rain is
possible with isolated accumulations of 5 to 6 inches possible
through Wednesday night.
The GFS continues to be more progressive with the trough axis
advancing across the Southern Plains through the middle of the
week. This would allow drier, post-frontal air to filter into the
region bringing a premature end to rain and storm chances. The
ECMWF continues to advertise a slower evolution with the trough
axis stalling to the southwest of our CWA which would hold upper
level support and moisture in place for storm chances to continue
across the region into the holiday weekend. In the absence of any
consensus among guidance, we will continue to favor the slower
solution as recent runs of the GFS are trending somewhat slower.
As mentioned in the short term discussion above, while the
likelihood of a flood watch is increasing due to forecast
potential for excessive rainfall we will postpone issuing a watch
at this juncture. Regarding temperature through this period: While
this system is not the deep push of cold air some of us are
hoping for it will provide welcome relief from the excessive heat
and humidity we have been muddling through recently. Expect cooler
conditions with highs from the low to mid 80s along and near the
Red River to the low to mid 90s in Central Texas. Lows will dip
down into the 60s and 70s by early next week.
12
&&
.AVIATION... /NEW/
/00Z TAFs/
VFR will prevail through this evening, but increasing
thunderstorm chances will occur later tonight through Tuesday
along with widespread MVFR cigs overnight into Tuesday. A low
level jet will transport moisture northward tonight resulting in
MVFR cigs after midnight. Thunderstorms to the northwest should
primarily ride along the Red River but will expand southward
toward morning. We`ll have VCTS by 11Z in the Metroplex with
prevailing TS around 14Z. There will likely be a break in the
shower/storm activity through afternoon before rain/storm chances
increase again Tuesday evening/night.
At Waco, VFR will prevail this evening with MVFR cigs
overspreading the region tonight. Thunderstorm chances will begin
to increase Tuesday afternoon and continue through Tuesday night.
Dunn
&&
.PRELIMINARY POINT TEMPS/POPS...
Dallas-Ft. Worth 80 96 76 88 74 / 40 60 70 70 40
Waco 80 100 77 93 75 / 20 30 40 50 30
Paris 75 87 73 82 71 / 70 70 70 80 40
Denton 78 93 74 86 72 / 60 60 80 70 40
McKinney 78 94 74 86 72 / 50 60 70 70 40
Dallas 80 96 76 89 75 / 40 60 70 70 40
Terrell 78 97 75 89 73 / 40 50 60 60 30
Corsicana 79 96 77 89 74 / 30 30 40 50 30
Temple 79 99 77 94 74 / 10 20 30 40 30
Mineral Wells 75 96 71 86 69 / 60 60 80 70 40
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
Heat Advisory until 8 PM CDT Tuesday for TXZ103>107-117>123-
131>135-144>148-157>162-174-175.
&&
$$
91
Area Forecast Discussion
National Weather Service Huntsville AL
937 PM CDT Mon Aug 31 2020
.NEAR TERM...(Rest of tonight)
Issued at 937 PM CDT Mon Aug 31 2020
Calmer weather prevailed across most of the Tennessee Valley this
evening, after a stormy afternoon and early evening. Shower and
thunderstorm activity that occurred earlier has for the most part
dissipated. At the moment, an area of light showers was heading ESE
across parts of NW Alabama, from south of the Quad City to the Golden
Triangle. Mid evening temperatures ranged in the 70s with light
winds.
Shower activity moving over NW AL was stronger convection a couple of
hours ago, with the satellite indicating a remnant cirrus cloud
shield tracking with the showers. Overall shower activity should end
towards midnight. In mostly clear areas between those higher clouds,
lower clouds and fog was beginning to form. Fayetteville was
reporting variable visible from 2-5 miles and low clouds bases of
less than 500 ft AGL. Given longer later summer nights, more patchy
fog formation is possible tonight. Areas that received, say more
than a tenth of an inch would be more susceptible for fog formation,
as well as those normally fog prone locations, and places near large
bodies of water.
The RAP and HRRR were hinting that an approaching upper system could
help generate isolated convection before daybreak over NW AL. Kept
this possibility in the grids, but scaled it back somewhat. Showers
will probably become more scattered to maybe numerous later Tue
afternoon with more heating and resultant instability.
.SHORT TERM...(Tuesday through Wednesday)
Issued at 232 PM CDT Mon Aug 31 2020
Active pattern continues on Tuesday as a weak shortwave trough will
shift NE from the lower Mississippi Valley and across the Mid-South
and Tennessee Valleys. Additionally, a remnant outflow boundary from
today`s convection will also stall over the area, serving as an
additional focus for convection. The end result will be another
round of scattered to numerous showers and thunderstorms from the
mid/late morning through the afternoon. As is the case today, locally
heavy rainfall/flooding will be the primary concern, along with the
possibility of some localized gusty winds from a couple of strong
storms. Would expect this activity to wane fairly quickly with the
loss of heating and the fact that the aforementioned shortwave will
have lifted well NE of the area after 00z.
An upper-high over FL/GA will then attempt to briefly build in the
Deep South on Wednesday. This ridge will help to keep a stronger
frontal system stalled to our northwest (at least for the time-
being), and subsequently result in a mostly dry day. In fact, the
latest guidance indicates that Wednesday will likely be mostly sunny
at times, with highs potentially reaching the lower 90s (and heat
indices around 100 degrees). Given this, Wednesday may well be the
warmest day of the week for most locations across our area.
.LONG TERM...(Wednesday night through Sunday)
Issued at 232 PM CDT Mon Aug 31 2020
The Tennessee Valley will remain wedged between a frontal system
just to its north and west across the Ohio Valley/Southern Plains
and a fairly strong Bermuda High that will attempt to remain
established across much of the Deep South for the remainder of the
work week. Behind this boundary much drier (more autumn-like) air
exists, while continued warm, muggy conditions will exist ahead of
this feature underneath the ridge. For Thursday and Friday, expect a
gradual uptick in the coverage of convection as an upper-trough
swings into the Ozarks and approaches the Mid South region. This
feature will help to generate some scattered showers and storms along
the aformentioned boundary just to our northwest which should be
stalled along the I-40 corridor of TN. Eventually, this boundary will
sag further south and east into the region on Friday afternoon and
evening , but do not expect to see more than scattered thunderstorm
chances once again as the stronger ridging aloft should win out.
However, as mentioned above, a cooler, drier air mass does exist
behind this boundary as the high retreats back off the NC/SC coast.
As a result, we can expect an early taste of autumn this weekend,
with lower RH and highs in the low to mid 80s -- to go along with
plenty of sunshine and lower PoPs.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 703 PM CDT Mon Aug 31 2020
Shower activity that affected KMSL and KHSV continues to weaken as
it moves eastward across NE AL. Other clusters of convection were
nearing Cullman county from the west, and another area of storms was
moving over north/central MS. The movement of both areas of storms
appeared a bit south of due east. Shorter term model output generally
have both areas dissipating during the course of the evening. Given
both KMSL/KHSV both had a wetting rain (~1/4 of an inch or more),
have included predawn patchy fog. Another approaching system and
daytime created instability should bring more scattered to numerous
showers/t-storms Tue afternoon.
&&
.HUN WATCHES/WARNINGS/ADVISORIES...
AL...NONE.
TN...NONE.
&&
$$
NEAR TERM...RSB
SHORT TERM...AMP.24
LONG TERM...AMP.24
AVIATION...RSB
For more information please visit our website
at weather.gov/huntsville.
Area Forecast Discussion
National Weather Service Wichita KS
644 PM CDT Mon Aug 31 2020
.SHORT TERM...(This evening through Tuesday night)
Issued at 145 PM CDT Mon Aug 31 2020
Afternoon/evening storm activity in the CWA continues to be highly
dependent on the location of the surface front. So far today, the
front has been outpacing models in its southeast progression through
the CWA. As the northern CONUS trough races out toward the northern
Great Lakes region, the forward progression of the front may try to
stall a bit as we head deeper into the afternoon. The front
currently bisects the CWA in a line from approximately Maple City in
Cowley County to Fall River in Greenwood County to Neosho Falls
in Woodson County. Any locations along and southeast of this line
should remain weather aware through the afternoon.
For areas of southeast KS which remain along/ahead of the front and
in the warm sector, large hail up to golf balls and damaging
winds up to 65 mph will be possible. The unstable airmass over far
southeast KS (according to RAP soundings) is characterized by
MLCAPE of around 3000 J/kg, mid level lapse rate of 7.7 C/km, with
35kts of effective shear. SRH has backed off since previous runs
as sfc winds have veered slightly, however, there would be a non-
zero chance of a tornado anywhere outflow boundaries(s) intersect
with the frontal feature which would locally (significantly)
affect the SRH given ambient semi-favorable 3CAPE of around 100
J/kg. A few boundaries can be seen via satellite and radar
currently bisecting the front, one moving NE out of OK and one
moving SW from the complex that has moved out of northeast KS into
southern MO.
Model consensus keeps a decent baroclinic zone across the CWA
tonight with no shortage of warm moist advection which should
prompt some elevated convection tonight, mainly over the southern
tier of counties. Looks like the moisture gradient will run just
east and south of the KS turnpike before veering out over
southeast KS toward the morning hours. Thinking that most of the
activity should remain in the vicinity of the KS turnpike and
points south and east. There are quite large differences between
model derived elevated instability, for instance NAM pushing
4,000+ J/kg MUCAPE vs RAP indicating 2,500 J/kg MUCAPE. In either
case, 1-6km shear of 20- 30kts would support some strong to severe
storms tonight. Though there is some uncertainty in the degree of
instability, thinking the strongest storms would be capable of
golf ball sized hail and damaging winds to 60 mph, with 700-500
directional shear being a less favorable factor. Localized
flooding from heavy rainfall will also be possible.
If the front continues to move southeast this afternoon and evening,
aided by outflow, and continues further south into Oklahoma, there
is a chance that tonights area of elevated convection would also
then shift south, so this will need to be monitored as we move
through the evening hours for any updates.
Tomorrow again, is very dependent really on where the cold front
ends up tonight. There`s a pretty good chance that it remains to
outpace models and ends up south into Oklahoma. The front should
start to try and work back north tomorrow as a warm front as it gets
influenced by the the deep upper trough that will have dug its way
into the Great Basin by late morning tomorrow. Thinking the
northward progression of the now warm front may not make it across
the OK/KS border tomorrow. Whether it does make it, or it doesn`t,
there doesn`t seem to be too much difference in terms of impacts.
Would expect that the environment be pretty worked over in general
from overnight convection so the severe threat would remain rather
isolated in nature. Should the front remain to our south tomorrow,
would still expect warm advection induced showers and storms to
impact the southern few rows of counties. Scattered shower/storm
activity may linger through Tues night-early Wed.
.LONG TERM...(Wednesday through Monday)
Issued at 145 PM CDT Mon Aug 31 2020
Another deep trough will push through the northern CONUS and drive
the southern stream trough out of the Great Basin and into the
southern Plains late Wed into Thu. It could mean a few more
showers and storms as the next cold front swiftly moves through
the region Thursday. Meanwhile, a western CONUS ridge will be
building each day through the extended, propelling the area back
into northwesterly flow aloft. This setup will bring much drier
conditions back to the area through the weekend with temperatures
trending up into the mid 80s.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 638 PM CDT Mon Aug 31 2020
A cold front was stalled over southeast Kansas this evening and
will remain in the area before slowly pushing southward. Meanwhile
low level moisture northwest of the front will yield low clouds in
the IFR category late tonight into Tuesday morning. Storms look to
redevelop over southeast Kansas late tonight and linger into the
morning hours. The low clouds will be stingy and could begin to
scatter out by Tuesday afternoon.
&&
.PRELIMINARY POINT TEMPS/POPS...
Wichita-KICT 67 83 65 84 / 50 40 20 20
Hutchinson 63 80 62 84 / 40 30 20 10
Newton 65 80 63 83 / 40 40 20 10
ElDorado 66 82 65 81 / 60 50 20 20
Winfield-KWLD 68 84 67 81 / 60 40 40 40
Russell 60 77 59 85 / 20 20 10 0
Great Bend 61 77 60 83 / 30 20 10 0
Salina 63 78 61 86 / 30 30 10 10
McPherson 63 79 61 84 / 30 30 10 10
Coffeyville 70 83 69 82 / 60 50 40 50
Chanute 69 82 67 82 / 60 60 30 40
Iola 68 82 67 83 / 60 60 20 30
Parsons-KPPF 70 83 69 82 / 60 60 30 40
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SHORT TERM...KMB
LONG TERM...KMB
AVIATION...CDJ
AREA FORECAST DISCUSSION
National Weather Service Wilmington OH
859 PM EDT Mon Aug 31 2020
.SYNOPSIS...
A series of upper level disturbances will bring occasional
chances for showers and thunderstorms through Thursday. A cold
front will push through the region Thursday night into Friday,
ushering in a cooler and drier airmass by the end of the week.
&&
.NEAR TERM /THROUGH TUESDAY/...
A mid-level trough is currently moving across Wisconsin, with
broad and generally unfocused southwesterly boundary layer flow
ahead of the trough over the Ohio Valley. Weak 925mb theta-e
advection appears to match up near the top of the boundary layer
as determined by the 00Z KILN sounding, with just enough lift to
spark some widely scattered showers this evening. As this
theta-e advection appears likely to persist through the
overnight, perhaps slightly more focused in the northwest ILN
CWA after 06Z, a 20 percent chance of showers will be maintained
through the overnight hours.
Fog is the other concern overnight, with the light surface flow
and plentiful moisture (dewpoints in the upper 60s to around
70). Guidance products and HRRR projections suggest fog will
become fairly widespread overnight, with at least some chance of
dense fog, particularly along and southeast of the Interstate 71
corridor. As mentioned previously, the lack of really solid
clearing will be one limiting factor, so confidence in getting
more than patchy dense fog is still not particularly high. It is
also possible that stratus will develop by 12Z, further
complicating the sky/visibility forecast.
Previous discussion >
We are still seeing some showers across our far south this
afternoon in an area of some weak low level convergence. With
some very weak mid level energy also pushing east across the
region, will linger some slight chance pops into early evening
for areas mainly to the south of the Ohio River. Will then dry
things out overnight as some very weak mid level ridging tries
to translate east across the region. In relatively light flow
at the surface and with lingering boundary layer moisture,
several of the models are suggesting the possibility for some
widespread fog development later tonight. This may be somewhat
dependent on how much clearing we end up with as we head into
tonight but will at least allow for some areas of fog
development later tonight. Lows tonight will be in the mid to
upper 60s.
&&
.SHORT TERM /TUESDAY NIGHT/...
Mid level short wave energy will lift northeast from the mid
Mississippi Valley Tuesday and across the upper Ohio Valley into
Tuesday night as a frontal boundary sags slowly toward our area
from the northwest. The potential for some lingering clouds
Tuesday morning may affect how much we are able to destabilize
through the afternoon. However, with temps into the mid 80s and
dewpoints slowly rising into the upper 60s/lower 70s, sbcapes
in the 1500 to possibly 2000 J/KG range may be possible through
late afternoon. This combined with the approaching short wave,
will lead to an increasing chance of showers and thunderstorms
from the west later Tuesday afternoon into Tuesday night.
Increasing low and mid level flow ahead of the short wave will
also lead to an increase in deeper layer shear heading into
Tuesday night. As a result, there may be a small window late
Tuesday afternoon into early Tuesday evening where a few
stronger storms may be possible, with gusty winds being the
main threat.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
Instability builds on Wednesday as the fa remains in the warm sector
of a surface Low , but models are in moderate disagreement with the
amount of CAPE. The GFS brings in 2000+ J/kg of CAPE over most
locations while the NAM limits it to counties along and south of
Ohio River. Decided to lean towards the NAMs resolution for
Wednesday as it appears storm coverage will be more isolated further
north.
A deepening H5 trough on Thursday will usher in a wave of PVA and
interact with a cold front sinking from the north, so keeping PoPs
likely throughout the afternoon / evening. Models push out the
precip by Friday morning as high pressure out of the northwest
settles in.
Cooler and drier air will ensue to start the weekend. The H5 trough
in the GFS is slightly more deep / enhanced compared to the Euro,
leading to forecasted temps about 5 degrees cooler for Friday and
Saturday. Went with a blend of the two across the fa, but generally
leaned towards the cooler side, more in line with the GFS.
Temps start to warm up on Sunday as the upper trough dampens and
flow becomes more zonal. Still anticipate dry conditions to persist
with limited forcing in place.
Scattered rain showers will return early on Monday with another
approaching cold front and upper trough digging into the Mid-
Atlantic. The GFS currently moves the precip out by end of morning,
so started decreasing PoPs in the afternoon. Afterwards, anomalously
low 850mb temps begin to advect into the fa, cooling off surface
temps rapidly heading into Monday night.
&&
.AVIATION /01Z TUESDAY THROUGH SATURDAY/...
Generally VFR conditions are expected at the start of the
overnight period, but these conditions will deteriorate after
06Z, with fog and stratus expected to develop. MVFR to IFR
ceilings and visibilities appear very likely for all TAF sites
(though KDAY may be more MVFR than IFR). A period of LIFR
conditions, possibly including dense fog and low stratus,
appears possible at KLUK/KILN/KCMH/KLCK during the 08Z-12Z time
frame. This set of TAFs has been adjusted to include some lower
visibilities and ceilings than the last update. Visibilities
should improve after 12Z, but low ceilings may persist for
another few hours.
VFR conditions are expected for all TAF sites by late morning or
early afternoon. Some showers and thunderstorms are expected by
mid to late afternoon, but with uncertain timing and only
scattered coverage. Thus, a VCSH will be included in the TAFs,
with specifics left for later updates.
OUTLOOK...Thunderstorms will be possible at times through
Thursday. MVFR conditions are possible again on Wednesday
morning.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...None.
KY...None.
IN...None.
&&
$$
SYNOPSIS...JGL
NEAR TERM...Hatzos/JGL
SHORT TERM...JGL
LONG TERM...Clark
AVIATION...Hatzos
Area Forecast Discussion
National Weather Service Marquette MI
736 PM EDT Mon Aug 31 2020
.SHORT TERM...(This evening through Tuesday)
Issued at 352 PM EDT MON AUG 31 2020
Water vapor satellite this afternoon shows a distinct dry punch
aloft over Wisconsin and the western UP, this associated with a
strong negatively-tilted mid-level short wave that is lifting
northeastward across the western UP and Lake Superior. At the
surface, this takes the shape of a narrow trough accompanied by a
tight wind shift as evidenced by south winds at Passage Island (east
end of Isle Royale) and NW winds at Rock of Ages (west end of Isle
Royale). Strong fgen is providing maple lift for showers moving
across the area. Initially, these were in a broader, more stratiform
area. However in the past hour or so some scattered heavier showers
have developed over western Marquette County where SPC Mesoanalysis
indicates up to 250 J/kg MUCAPE. Even the most generous HRRR
sounding wrt instability keeps ELs below the hail growth zone, and
with cloud-phase satellite showing only very little ice growth, felt
ok keeping thunder out of the forecast. However, some briefly
heavier rainfall rates will be possible the next couple of hours.
This evening, precip will clear out from west to east as the front
races through. Initially skies will be clear, allowing for some
cooling. However, satellite and models show a thick patch of cirrus
racing in from the west that will move over the area by late
evening, inhibiting cooling somewhat. Still, given the cool air
aloft behind this front it will be a seasonably chilly night (lows
in the 40s interior and 50s lakeshores). Despite today`s rainfall,
think that we will maintain a few kts of gradient wind which, along
with this cirrus, should prevent much if any fog from forming.
Tomorrow, temps begin warming aloft again, from about 8 C in the
morning to about 11 C by late afternoon at 850 mb. However, this
comes as the next short wave (this one much more strung out) bring
more mid-level cloud cover in by afternoon, keeping temps from
warming too much. Highs should make it into the low 70s across the
board.
.LONG TERM...(Tuesday night through Monday)
Issued at 355 PM EDT MON AUG 31 2020
At the start of this forecast period, Upper Michigan will be
sitting in between two bouts of precip to the NW and SE. The one
sliding northeastward to the southeast of the area may skim
portions of the far southeastern U.P., with this round courtesy of
being triggered by the leading edge of an upper trough axis
swinging overhead. To the NW, that precip is more directly
associated with the trough axis itself as an upper jet moves in.
This jet/trough looks to weaken as it crosses the Upper Great
Lakes, with not a whole lot of atmospheric moisture accompanying
it, thereby reducing more widespread precip chances with this
system.
Brief benign period then occurs before the next, potentially more
robust system knocks on the door, although similar to how the
models have been handling these more fall-like system tracks as of
late, may be a bit overdone, particularly the GFS. Nonetheless,
it`ll be windy with some rain in the area, but the extent of the
wind and rain is yet to be seen. All of the models are in
agreement in intensification of the low, but differ on its track
(i.e. if further north, less rain chances, lower wind speeds).
Stay tuned, particularly those with marine interests (see below).
In the extended period, the pattern looks to remain unsettled with
repeated visits from shortwaves and other disturbances, keeping
the chances for rain somewhat persistent. Not a washout every day
by any means, but just nuisance-type shower activity is what is
currently looking to occur. As for temps, it will wobble between
near to a few degrees below normal through the entire forecast
period, with the warmest day likely happening on Wednesday. If a
fan of the warmer temps, enjoy it while it lasts as early next
week could usher in much cooler weather. Expect 40s and 50s for
lows through the period.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 732 PM EDT MON AUG 31 2020
VFR conditions expected at all terminals through the forecast
period. Southwest wind gusts of 20-25 knots could develop in the
afternoon, mainly at KIWD and KCMX.
&&
.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 422 PM EDT MON AUG 31 2020
The active pattern continues. A sharp trough/occluded front is
moving quickly northeastward across the lake this afternoon.
Southerly winds out ahead of it have been in the 20-30 kt range, now
confined to the eastern half of the lake, while immediately behind
the trough there has been a quick wind shift to westerly and an hour
or two period of gales. Have observed gale force gusts at the
western lake buoy, Rock of Ages, and Houghton this afternoon,
however winds have already relaxed back into the 20-30 kt range at
all three of these sites. Winds will continue to relax into the 15-
20 kt range this evening and through the day tomorrow.
Winds, particularly across the western portions of Lake Superior,
will be on the increase late tomorrow night into early Wednesday
with a few gusts to gale-force possible. Elsewhere across the lake,
gusts look to generally range in the 25 to near 30 knot range. By
early Thursday, more widespread gale-force gusts look likely,
spreading from west to east as the day progresses. However, there is
some uncertainty as to just how high these gusts will get given some
model discrepancies in the track of the low pressure system
responsible for these winds. Regardless of these finer details,
expect gales for this time period, tapering off by late Thursday
into early Friday.
For the first half of the weekend, gusts should top out around 20
knots, with the next system of interest potentially ushering in
higher winds toward the tail end of next weekend.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
Beach Hazards Statement until 9 PM EDT this evening for MIZ014.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
SHORT TERM...RJC
LONG TERM...lg
AVIATION...Voss
MARINE...RJC/lg
Area Forecast Discussion
National Weather Service Reno NV
306 PM PDT Mon Aug 31 2020
.SYNOPSIS...
Temperatures remain near normal through Tuesday. Winds turn easterly
this evening into Tuesday helping to ease smoke impacts for many
spots for at least the next couple days. An unusually warm air mass
takes hold mid-week through the Labor Day weekend with temperatures
likely to reach near record highs starting on Thursday. Very low
chances for thunderstorms return to the Sierra next week.
&&
.DISCUSSION...
It looks like we will finally see a better scouring of smoke/haze
in western and west-central Nevada starting later this evening,
with the Sierra possibly having to wait until late tonight or
Tuesday to see the same. Before late evening, west-northwest flow
for the Sierra into western NV may allow some additional smoke
transport to begin; however, after about 9 PM north to northeast
flow deepens such that additional smoke transport should be cutoff
and keep air quality from deteriorating too badly as compared with
previous nights.
On Tuesday, haze should decrease or even dissipate for improved
visibility as solid easterly flow is expected to keep most smoke
in California. Speaking of California, it may take longer than
western NV to scour smoke/haze in the Tahoe area as lighter winds
overnight could allow for smoke to remain in the Basin/Martis
Valley until mixing ensues on Tuesday. For Mono County, a similar
situation is possible although easterly flow may keep a small area
under the smoke gun in and to the west of the Antelope Valley.
Temperatures will remain around average through Tuesday before
we begin a substantial warm-up heading into the Labor Day weekend.
Overnight lows in valleys will be able to cool off efficiently
for at least the next few nights as winds diminish and the dry air
mass settles in.
For mid-week through the Labor Day weekend, an unusually strong
area of high pressure will build across much of the western US
including CA-NV. Deterministic GFS/ECMWF solutions continue to
show heights rising to 595-600 DM with very warm positive 2 meter
temperature anomalies. The MEX guidance still shows multiple days
(starting Thursday) at or above 100 degrees for western NV cities,
with the MEX pushing 90 degrees for Truckee and South Lake Tahoe.
Our latest day to hit 100 degrees at KRNO is September 4th, which
was set last in 2017. So, if the guidance holds, we would be
looking at multiple days for records including the latest day to
reach 100 degrees in a year. The one consolation will be the dry
airmass and the shortening days which will allow overnight
temperatures to at least cool back into the 40s Sierra valleys and
50s to mid 60s for warmer lower valleys. Be prepared for unusually
hot afternoons this Labor Day Weekend.
As far as thunderstorms, normally this magnitude of heat will
generate thunderstorms eventually as daily mixing and weak moisture
advection allow for enough instability to overcome the very warm
temperatures aloft. The first hint at storms is this weekend, but
probabilities remain low suggesting they will be very isolated and
mainly confined to the Sierra. -Snyder/Hohmann
&&
.AVIATION...
* Northeasterly flow behind a passing cold front is bringing slowly
improving visibility with less smoke to many areas today. Expect
this trend to continue tonight into Tuesday following latest HRRR
Smoke guidance. Still a bit of haze so slant-wise visibilities
will remain iffy. Areas of MVFR smoke conditions expected in the
Sierra (e.g. TRK, TVL, MMH) through this evening but those should
clear out to VFR by daybreak Tuesday as NE flow increases.
* Most areas should remain VFR Wednesday with N/NE flow however some
sneaky westerlies could bring haze/smoke back into Sierra spots
such as SVE, TRK, TVL late in the day.
* Unusually strong ridge of high pressure overspreading the region
for the coming holiday weekend will bring near-record temperatures
and isolated mountain t-storms or buildups. Some density altitude
considerations possible as well.
-Chris
&&
.FIRE WEATHER...
* Gusty N/NE winds will continue into this evening. With unusually
low humidity, some spots of critical conditions are possible in
wind prone areas of the Eastern Sierra and into the Highway 95
corridor. Not widespread nor long enough duration for warnings but
still awareness should be elevated into this evening.
* Humidity recoveries should be dramatically better for much of W
Nevada and NE California (+30% in zone 423 where MaxRH was as low
as 14% this morning!). Parts of Tahoe and the Eastern Sierra
however will have similar or slightly lower MaxRH values vs last
night. Gusty NE winds will persist overnight on mid-slopes and
ridges around the region, which could impact ongoing fires. Flow
relaxes Tuesday morning after daybreak.
* Still looking at a rather impressive heat wave starting Thursday
and lasting through the holiday weekend. Near record daytime temps
are likely especially Saturday into Monday. This is also when
guidance is showing larger areas of high Haines with dry/unstable
conditions. This could yield plume dominated fire behavior even
with only typical zephyr breezes. Isolated t-storms and buildups
are expected over the high terrain each afternoon.
-Chris
&&
.REV Watches/Warnings/Advisories...
NV...None.
CA...None.
&&
$$
For more information from the National Weather Service visit...
http://weather.gov/reno