Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 07/12/24
Area Forecast Discussion
National Weather Service La Crosse WI
1041 PM CDT Thu Jul 11 2024
.KEY MESSAGES...
- Some fog potential overnight, otherwise a quieter day expected
for Friday.
- Temperatures increasing into the weekend with highs in the
upper 80s to low 90s and heat indices nearing 100 by Sunday.
- Monitoring how the risk for severe weather unfolds for
Saturday evening through Tuesday. The forecast remains complex
and of lower confidence.
&&
.DISCUSSION...
Issued at 318 PM CDT Thu Jul 11 2024
Rest of Today - Tomorrow:
Currently, GOES-16 water vapor imagery and 11.14z RAP 500mb heights
shows a synoptic trough slowly pushing eastbound with a shortwave
ridge positioned to our northwest. As we head through the afternoon,
increasing instability (1000-1500 J/kg of MLCAPE) and some weak
cyclonic flow may help develop showers, maybe an isolated storm.
However with very weak shear profiles in the 11.14z RAP, would not
expect any convective development to maintain in any organized
fashion. However, with the 11.12z HREF showing ensemble max values
for 3-hr QPF of up to around 1", could not completely rule out
extremely localized areas receiving some higher totals.
As we head into tonight, subsidence builds in with the
aforementioned ridge allowing for more clearing in sky cover and
calming winds. As a result, expecting some fog formation overnight,
primarily in river valley locations and in central Wisconsin. Still
some questions for coverage and density for fog with the 11.12z NAM
trying to hold onto some saturation at 850mb in addition to some
increased low-level winds at 925mb to around 10 kts. Regardless,
with the aforementioned subsidence in place, should be a drier
forecast for Friday outside of a few possible sprinkles across north-
central WI with temperatures reaching into the middle 80s for most.
Saturday - Sunday:
A challenging forecast remains for the weekend as we monitor the
potential for storms. The ridge that has persisted over the West is
forecast to build towards the region on Saturday with a series of
upper level shortwaves riding around it. With increasing moisture
and warm air advection beneath an EML, strong instability looks to
build across the region. Some indication in model guidance for
elevated convection to develop early as one of the aforementioned
waves moves through. However, as we continue to move into the day
there remains some concern revolving around capping. Latest ensemble
guidance, as an example/proxy, keeps us right on the eastern edge of
the 700 mb temperature probabilities for 12C+ with model forecast
soundings showing a bit less of a capped environment in the east.
With a weak moisture transport convergence signal into southern
Wisconsin along with the warm front, guidance suggests this could be
enough to get showers and thunderstorms to develop. However, there
seems to still be plenty of variability on how that evolves. Will
need to continue to monitor trends over the next day or so,
especially as we remain in a slight risk for severe weather from
SPC.
The story remains the same as with previous forecasts for Sunday,
which will be dependent on Saturday`s convection as well as the
strength of the cap building across the area. Model guidance again
diverges quite a bit on how exactly this unfolds and where storms
track. Overall though, current thinking would be that storms will
track along the gradient of the instability pool and weaker capping
(potentially favoring more north/northeast). With the strong
instability and better shear to work with will be closely monitoring
over the next couple days for the potential for severe weather.
Of higher confidence is for increasing temperatures into the
weekend. Sunday still looks to be the warmest day coming up, with
current forecast high temperatures in the upper 80s to low 90s. This
is supported by quite low spread (~2-3 degrees) between the 25th and
75th percentiles of the blended model guidance. There does not look
to be much relief for the overnight as temperatures only drop into
the 60s to low 70s. With the addition of increased dewpoint
temperatures, heat indices may rise into the 90s to near 100 for
some especially Sunday. Now, will note that one wrench in this would
be any impacts from potential convective systems Saturday night into
Sunday morning. Something to monitor as these details become more
clear, but for now will continue to message the heat.
Into Early Next Week:
Some signal for an upper level trough to move across the region with
additional showers and storms possible. However, it is uncertain how
any convection on Sunday will impact storms on Monday. Otherwise,
the heat does not look to last long as temperatures drop back to the
70s by mid-week.
&&
.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 1028 PM CDT Thu Jul 11 2024
Primary concern remains to be valley fog along the Mississippi
and Wisconsin rivers and their tributaries. Light wind layer and
clear skies at 12.06Z TAF issuance increases confidence for
dropping into LIFR visibilities and ceilings. Therefore, have
introduced BR and 003 ft ceilings. Otherwise, VFR with light
winds through Friday.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
IA...None.
&&
$$
DISCUSSION...EMS
AVIATION...JAR
AREA FORECAST DISCUSSION
National Weather Service Jackson KY
1140 PM EDT Thu Jul 11 2024
.KEY MESSAGES...
- Hotter conditions make a comeback as we move into the weekend
and for next week.
- The next significant chance of rain will hold off until the
middle of next week.
&&
.UPDATE...
Issued at 1140 PM EDT THU JUL 11 2024
A weak mid-level wave is pushing across the Ohio Valley. This
continues to lead to a few showers right along our CWA border
mainly in Rockcastle and Pulaski counties. Did keep this for a few
more hours in these areas, but these are expected to dissipate
later this evening into the overnight. The NBM PPI continues to be
of little help in the situation and favored some of the other
short term models and blends for adding these PoPs in longer.
Outside this very minor updates needed for the latest obs and
trends.
UPDATE Issued at 819 PM EDT THU JUL 11 2024
A few rain showers have developed right along our CWA border near
Pulaski and Rockcastle counties. Given this opted to add in around
15 to 20 percent chance of rain in these locations. Outside of
that no big changes needed.
UPDATE Issued at 558 PM EDT THU JUL 11 2024
The surface analysis shows high pressure continues to work into
the Great Lakes this afternoon. In the mid-levels, a shortwave
trough is pushing across portions of the Ohio Valley. This is
aiding in sparking off a few showers and thunderstorms to the
northwest of eastern Kentucky. Most of the CAMs have this activity
decreasing through the evening, but the HRRR has shown some signs
this could maintain and get closer to the area late this evening.
Right now leaning toward dry weather through the evening, but did
opt to increase cloud cover given the latest trends on Satellite.
Outside this overall minor updates were made to the forecast.
&&
.SHORT TERM...(This evening through Friday night)
Issued at 320 PM EDT THU JUL 11 2024
Current surface analysis has surface high pressure situated over the
much of the eastern CONUS. The remnants of Beryl is exiting off the
northeastern coast and a weak surface low is tracking across the
Central Plains with a wavering frontal boundary extending into the
Ohio Valley. Locally, high pressure is keeping the CWA warm and dry
with a widespread field of fair weather cumulus clouds.
Aloft, troughing is situated over the Great Lakes with the CWA under
the regime of the upslope side of the trough. Through the afternoon
into Friday, the trough will pivot through the area. At the surface,
high pressure will remain in place but a few showers and storms may
try to develop this afternoon along the aforementioned frontal
boundary but those PoP chances will largely remain confined to areas
west of the CWA. Clouds will decrease overnight and a decent ridge-
valley split will set up tonight; as well as, areas of patchy dense
valley fog.
Friday brings much of the same weather as surface high pressure
remains in place. The upper-level trough will pivot through the area
but once again, not expecting much in the way of PoPs. CAMs try to
bring a few isolated showers or storms to the I-75 corridor but
chances are less than 15% in those areas. Similar to Thursday night,
a mostly clear night is expected again Friday into Saturday where a
ridge-valley split sets up and valley fog will develop and persist
through early Saturday morning.
Overall, the period will be dry with passing clouds. Highs are
forecast to be in the mid to upper-80s today before climbing into
low 90s for Friday. Overnight lows will remain mild across the area
too, as lows tonight will drop into the low to mid-60s and mid to
upper-60s for Friday night.
.LONG TERM...(Saturday through Thursday)
Issued at 320 PM EDT THU JUL 11 2024
The first several days in the extended should be hot and mostly dry,
as high pressure settles over portions of the southeastern and
southern CONUS. We might see a few showers and storms Sunday
afternoon north of Highway 80, and again Monday evening, as a couple
of weak disturbances pass by to our north. Our next good chance will
likely not arrive until late Tuesday, as a more substantial system
moves across southern Canada, and drags a cold front through the
Great Lakes and Ohio and Tennessee Valleys. It appears that the
front will get hung near or over our area by Wednesday, keeping rain
chances in the forecast through near the end of the week. Weak
impulses moving along the sluggish boundary will be triggers for
showers and storms as well.
As for temperatures, it looks like we will see a return to hot and
muggy conditions in the extended. The latest run of the NBM was way
too hot for Monday and Tuesday, and initially had highs on those two
days maxing out in the mid to upper 90s, which would be incredibly
difficult to achieve in our area. Even with dewpoints expected to
rise into the upper and lower 70s, we should still see daily highs
mainly in the lower 90s, with a few locations perhaps reaching the
mid 90s. We should see a nice cool down at the end of the period, as
the cold front drifts to our south and persistent rain and clouds
are in place. Highs next Thursday should only be in the low to mid
80s. As far as weather concerns go, we will keep an eye on just hot
and humid conditions become the first few days next week. If any
concerns arise with regards to the heat, we will keep everyone
informed.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
ISSUED AT 731 PM EDT THU JUL 11 2024
The period will remain mostly VFR across eastern Kentucky. We have
seen cumulus develop this afternoon at around 5 to 6 kft. These
have been producing some showers just to the west of eastern
Kentucky, but not expecting any showers to affect TAF sites at
this point. We could see these clouds stick around through the
evening before dissipating later tonight. Once clouds dissipate we
will see the potential for valley fog developing under clear and
calm conditions. Given this added in fog at SME, but otherwise
kept other sites VFR for now. This fog is expected to dissipate
around 12Z and VFR will return area wide for the remainder of the
period. The winds will remain light and variable for the period.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...DJ
SHORT TERM...VORST
LONG TERM...AR
AVIATION...DJ
Area Forecast Discussion
National Weather Service Springfield MO
654 PM CDT Thu Jul 11 2024
.KEY MESSAGES...
- Scattered showers and thunderstorms into Friday. A few storms
may produce wind gusts up to 60 mph and hail to the size of
quarters into this evening.
- Heat indices climb into the 100-107 degree range from Sunday
through Wednesday.
- A cold front will bring the potential for more thunderstorms
to the region next Wednesday or Thursday along with cooler
temperatures.
&&
.SHORT TERM /THROUGH FRIDAY/...
Issued at 154 PM CDT Thu Jul 11 2024
Synoptic Scale Pattern and Current Conditions:
Water vapor imagery depicts a short wave trough diving southeast
across the Great Lakes with a secondary lobe of vorticity
dropping south across the Corn Belt. At the surface, a front has
stalled out in the vicinity of the I-70 corridor from northeast
Kansas into Missouri. An outflow boundary from morning storms
is dropping south through central Missouri and is becoming more
diffuse with time.
A loose cluster of showers and thunderstorms that persisted for
much of the morning, has now almost vanished in the vicinity of
Rolla and Dixon. Sky conditions as of 2 PM range from mostly
sunny to partly cloudy. Temperatures over most areas have warmed
into the middle 80s to lower 90s. A few locations across
central Missouri remain in the lower 80s due to slightly greater
cloud coverage.
Thunderstorm Potential through Mid-Evening:
Upper level ascent will increase as that short wave trough in
the Corn Belt moves into northern Missouri. In addition to the
upper level ascent, surface temperatures will near convective
temperatures which are in the upper 80s to lower 90s per the 12Z
KSGF RAOB as well as short term RAP initializations. These
factors along with weak convergence along that outflow boundary
will result in widely scattered thunderstorm development into
early this evening.
MLCAPE values ahead of the outflow boundary will be in the
1500-2500 J/kg range with deep layer shear of 25-30 knots.
This will be supportive of a few storms potentially reaching
marginally severe levels. Hail to the size of quarters and
damaging wind gusts to 60 mph will be the primary potential
severe weather hazards.
Low temperatures tonight will range from the middle 60s across
the eastern Ozarks to the lower 70s around Joplin and Neosho.
Thunderstorm Potential from Late Tonight into Friday Morning:
That surface front will remain stalled somewhere near or just
south of I-70. Meanwhile, short term models are in good
agreement that a low-level jet will develop and strengthen
across Oklahoma and eastern Kansas starting late this evening.
This feature will then veer into far western Missouri starting
late tonight.
Lifting parcels from planes in the 850-750 mb layer yields
800-1600 J/kg of CAPE with little in the way of inhibition. We
therefore think that isentropic upglide will initiate widely
scattered elevated thunderstorms across western and central
Missouri after midnight. This activity will then slowly work
east across the Missouri Ozarks through Friday morning.
The main potential hazards with overnight and Friday morning
activity will be hail to the size of pennies and perhaps wind
gusts to 50 mph if wind can penetrate the nocturnal inversion.
Friday Afternoon and Friday Night:
Morning activity may very well survive into the afternoon as it
pushes into the eastern Ozarks. Otherwise, a few pop-up storms
will be possible (20- 30% chances) primarily across the eastern
Ozarks during peak heating. A capping inversion may limit, or
completely eliminate any potential for convective development in
the afternoon along and west of the Highway 65 corridor.
The experimental Ozarks Pulse Severe Thunderstorm Index
indicates that any storms that form across the eastern Ozarks
Friday afternoon will have the potential to produce damaging
downbursts and perhaps hail to the size of quarters. Until we
can get a better feel for thunderstorm potential Friday
afternoon, we are going to continue adverting wind gusts to 50
mph and hail to the size of pennies as the primary convective
hazards across the eastern Ozarks. Wind gust and hail size
values may need to be nudged upward in future forecasts.
A slow warming trend will continue into Friday as a ridge over
the western U.S. slowly continues to build east. The NBM shows
tight clustering with high temperatures on Friday. Thus,
confidence is high that temperatures will range from the middle
and upper 80s across the eastern Ozarks to the lower and middle
90s along the I-49 corridor.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
Issued at 154 PM CDT Thu Jul 11 2024
Friday Night into Saturday:
That warm front will lift north as the upper level ridge
continues to build east. Most ensemble members keep the Ozarks
dry for this period with thunderstorm activity well north and
east of the area closer to that lifting warm front.
One alternative scenario depicted by some short term ensembles
is the development of elevated convection and potentially even
an MCS across northern Missouri from late Friday night into
Saturday morning. If the MCS scenario were to materialize, wind
fields would support the MCS dropping south into central
Missouri and the eastern Ozarks.
If we remain dry with little in the way of cloud cover (the most
likely scenario) on Saturday, we will have no problem
continuing our warming trend with most areas warming into the
lower and middle 90s. If the MCS scenario does indeed come to
fruition, we would see slightly cooler temperatures due to the
precipitation and cloud cover.
Sunday into Tuesday:
Global ensembles show strong agreement that the upper level
ridge will continue to build east into the area. Dry weather
and hot conditions will be the result. Highs by Monday and
Tuesday will be in the middle 90s to around 100 degrees with the
warmest readings along the I-49 corridor. Confidence is high in
these temperatures given that the NBM statistical data only has
2-4 degree spreads between its 25th and 75th percentiles.
We are still expecting afternoon heat indices of 100-107
degrees early next week as dew points remain in the middle 60s
to lower 70s. Heat headlines will correspondingly be in play.
Wednesday and Thursday:
Global ensembles continue to depict a large amplitude upper
level trough diving southeast through Hudson Bay and the Great
Lakes. We are becoming increasingly confident that this trough
will drive a cold front south either into or through the
Missouri Ozarks. This is supported by the vast majority of
global ensemble members.
The passing front will bring us our next shot at showers and
thunderstorms along with a return to near or slightly below
normal temperatures.
&&
.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 654 PM CDT Thu Jul 11 2024
Isolated showers and storms will continue to develop across
portions of west central and central Missouri this evening. The
better potential for this activity will remain north of the TAF
sites this evening so have not included any mention for
convection in the TAFs for this evening. Even with the storms
remaining north of the area it is possible that outflow from the
storms could move south into the TAF sites this evening and
result in a brief wind shift. Other wise south to southeasterly
winds will occur through the TAF period.
Additional scattered storms will be possible across the area
late tonight into Friday morning as lift moves into western
Missouri. Have PROB30 group for this thunderstorm potential in
both the Joplin and Springfield TAFS. Brief MVFR to IFR
conditions and erratic winds will be possible with any storms.
&&
.CLIMATE...
Issued at 154 PM CDT Thu Jul 11 2024
Record High Minimum Temperatures:
July 15:
KSGF: 79/1954
July 16:
KSGF: 81/1914
July 17:
KSGF: 79/1934
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
KS...None.
MO...None.
&&
$$
SHORT TERM...Schaumann
LONG TERM...Schaumann
AVIATION...Wise
CLIMATE...Schaumann