Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 06/26/24
Area Forecast Discussion
National Weather Service Columbia SC
818 PM EDT Tue Jun 25 2024
.SYNOPSIS...
Hot temperatures with heat indices over 100 F are expected to
continue through the period. Isolated to scattered showers and
thunderstorms should occur each afternoon and evening,
particularly in the eastern Midlands and coastal plain. As a
front approaches, better coverage is likely Thursday.
Increasing heat impacts Friday through the weekend. Another weak
front will move into near the area Monday with possible better
convective coverage.
&&
.NEAR TERM /UNTIL 8 AM WEDNESDAY MORNING/...
KEY MESSAGES:
-Mostly clear with lows in the mid-70s.
Evening satellite imagery shows convective debris clouds
diminishing across the eastern Midlands with a few lingering
cumulus elsewhere. Mostly clear skies and dry conditions are
expected through the overnight hours with the potential for low
stratus and/or patchy fog towards daybreak. It will be a muggy
night as dewpoints rise into the 70s throughout the forecast
area. Temperatures meanwhile only fall into the mid-70s.
&&
.SHORT TERM /8 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/...
KEY MESSAGES:
-Hot conditions to continue with max heat indices of 105-110
likely on Wednesday.
-Isolated to scattered afternoon/early evening thunderstorms,
greatest coverage in the southeast Midlands Wednesday.
-Highest chances of showers and thunderstorms Thursday, some
possibly severe. Wind damage is the main threat.
Wednesday: Broad troughing to our north will steadily help
drive some weak height falls across the area as we move into
Wednesday. Moisture will pull northward as the lingering
boundary lifts along southerly low level flow. So much of the
area will yield dew points into the 70`s again as PWAT`s climb
to around 1.5". PWAT`s will be a bit limited by some weak
downsloping flow aloft and the relatively dry northwest flow
above 850mb but this allow for strong solar heating. So again
high temps will cruise into the upper 90`s or low 100`s and with
the enhanced moisture, heat indices will likely top out around
110; a heat advisory will likely be needed for parts of the
area. Shower and storm activity will remain generally confined
to the sea breeze and coastal plain, but will likely push
further west into the Midlands compared to Tuesday.
Thursday: Troughing will continue to dig across the eastern US
with an associated low pressure system and front dragging
southward towards our area. While the best height falls will
shift north of us across the Mid-Atlantic, low level moisture
and plenty of heating will allow for some modest destabilization
in the afternoon; even the over-mixed GEFS still yields a mean
near 1500 MU CAPE and near 1000 ML CAPE. So while the forecast
soundings are not extremely impressive for severe weather,
anytime we have a synoptic- mesoscale lift source, dew points in
the upper 60`s or 70`s, and high temps in the upper 90`s,
severe weather is possible.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
KEY MESSAGES:
-Increasing heat impacts expected Friday through the weekend
with heat index values 105 to 110.
-Scattered afternoon thunderstorms each day.
Behind the boundary and trough passage on Thursday, broad flat
ridging will develop across much of the Southeast US. GEFS and
EC members are consistent in pulling the primary jet well north
across the Great Lakes, positioning us under the zonal,
slightly northwesterly flow regime of the ridge. Temps will
steadily climb each day through this period as the ridge builds
further and shifts east slightly. The warmest temps are expected
likely on Sunday with some downsloping component below 700mb in
the GEFS and EC means; NBM 75th percentile, which is verifying
well recently, is 100 F both Saturday and Sunday. Rain chances
increase sharply into Monday and Tuesday as the ridge breaks
down and more troughing digs to our north. Confidence is
relatively low on how this will materialize however given the
current pattern.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
VFR conditions expected through the TAF period although there is
the possibility of some brief stratus around dawn Wednesday.
Upper ridge over the southwestern states continues to ridge into
the southeast. Afternoon convection has diminished and lingering
debris clouds should also dissipate through the evening. Winds
generally expected to be light and variable overnight although
some outflow winds from the southeast 5 to 8 knots expected the
first hour of the forecast. A 20 knot low level jet is forecast
overnight which should limit fog concerns but there is some
mixed signals for the potential of stratus development after
09z, particularly across the eastern Midlands and Pee Dee
region. HRRR shows the development of stratus with some higher
probabilities shown on the SREF at OGB but lower elsewhere,
while the MOS guidance and NBM guidance does not have any
stratus forecast. Compromised a bit and included a tempo group
for stratus at most favored location OGB from 09z-13z and kept
it out elsewhere but trends may need to be monitored in future
forecasts for potential inclusion as prevailing or at CAE/CUB as
well as moisture begins to return north overnight. Probabilities
are low at AGS/DNL for stratus. Winds pick up from the south
once the inversion breaks Wednesday and speeds should increase
to around 7 to 10 knots by afternoon.
EXTENDED AVIATION OUTLOOK...Increased chance of rain and
restrictions on Thursday and Friday as an upper trough moves
into the region.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...None.
GA...None.
&&
$$
Area Forecast Discussion
National Weather Service Des Moines IA
637 PM CDT Tue Jun 25 2024
...Updated for the 00z Aviation Discussion...
.KEY MESSAGES...
- Strong to a few severe storms late afternoon into the evening
with main concern from large hail, damaging winds and locally
heavy rainfall central and south.
- Larger complex of storms overnight across southwest half of
Iowa with damaging winds main concern.
- Hydrologic discussion below main discussion details ongoing
river flooding and future locally heavy rainfall potential
- Drying out this weekend with more seasonal temperature and
humidity this weekend
&&
.DISCUSSION...
Issued at 248 PM CDT Tue Jun 25 2024
Boundary has settled down into the state this afternoon with
lingering isolated convection into southern Iowa. Temperatures have
once again climbed into the low 90s over the southern two-thirds of
Iowa outside the areas with clouds with heat index values hovering
around 100 in most locations in central and southern Iowa. The
convection in the south has persisted but coverage has slowly been
decreasing into the early afternoon with a bit of a col region in
the low levels moving into southern Iowa. However, another weak
wave is currently over the Nebraska Sandhills and is forecast to
move southeast into tonight helping to produce the upcoming weather
across the state. Instability is once again very strong with the
high dewpoints and temperatures but is still be suppressed by
relatively warm mid level temperatures. CAMS have continued to
produce some isolated to scattered convection starting late this
afternoon near the boundary in an east west corridor across the
central portion of the state. Low level shear is relatively weak
and the main concern with these storms will be large hail with the
initial updrafts and then possible strong to severe wind gusts as
the storms mature. There is the possibility of a brief tornado
during the development stage, but given the weak surface flow and
low level shear, this threat remains very limited. However, with the
high amounts of moisture, the storms may also produce locally heavy
rainfall and perhaps an isolated flash flood event, but widespread
heavy rainfall is not anticipated with these storms.
As the evening progresses, the weak wave in Nebraska moves east with
additional convection developing in eastern Nebraska into western
Iowa. The HRRR has been steadfast since late yesterday in
organizing this convection into a line and pushing it southeast
through central and southern Iowa tonight along the instability
gradient. More recently, the larger scale models also indicate an
MCS developing as the low level jet intensifies this evening and
passing through the state in similar fashion into tonight.
Therefore, have increased the PoPs through this evening into the
early morning hours central and south in anticipation of this
convective system. Damaging winds will be the primary threat with
the storms with hail as a secondary. The 0-3KM shear vector is
marginal at 25-30kts, therefore any QLCS tornado threat may be
somewhat limited. Otherwise, the other concern will be from heavy
rainfall although the progressive nature of the system is likely to
limit the overall flash flooding threat. This activity departs the
south towards daybreak on Wednesday with drier and cooler air
arriving from the north.
Quiet conditions are then forecast through Wednesday into much of
Thursday morning as subsidence and a drier airmass remain in place
across much of the state. However, warm advection and increasing
theta-e advection by later in the day and particularly Thursday
night into early Friday is likely to lead to widespread convection
into Iowa, particularly across the southern half of Iowa. Some
redevelopment of storms may occur in the far south on Friday
afternoon prior to a front passing through the entire forecast area,
but it appears that a good portion of the area should remain dry.
Cooler and drier conditions return for the weekend with relatively
pleasant weather for outdoor activity. A return to more active
weather is then anticipated into next week as upper flow becomes
more west to southwest across the western half of the CONUS.
&&
.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 636 PM CDT Tue Jun 25 2024
Main concern is ongoing convection affecting DSM and OTM.
This will likely persist through 05z with a second round
possible aft 06 to 07z possibly affecting DSM again aft 06z.
Aft 11z most of the storms will be moving away from the region.
/rev
&&
.HYDROLOGY...
Issued at 248 AM CDT Tue Jun 25 2024
Moderate to record river flooding is occurring or is forecast on the
West Fork Des Moines River, mainstem Des Moines River and parts of
the Cedar River basin. The greatest immediate concern is river
forecasts from the Humboldt area down to Fort Dodge. The crest may
come in lower than expected but still significant. We continue to
assess the data including real-time, in-situ river flow measurements
made by our partners at the U.S. Geological Survey (USGS) which
help us in the river forecast process. Some of the USGS staff endure
dangerous conditions to make these measurements because they
sometimes require wading or boating into the floodwaters and swift
currents.
NASA SPoRT relative soil moisture (RSM) continues to show more
limited capacity over northern Iowa mainly north of U.S. Highway 20.
Fortunately, much of the rainfall for later today into tonight is
forecast to fall south of Highway 20 where RSM is lower/more
capacity is available. This is also where USGS daily and 7 day
streamflows shows river basins in the normal percentile versus
northern Iowa at much above of high streamflows. Thus, again
suggesting some capacity for rainfall that falls later today into
tonight.
The next chance for rainfall will be later Thursday through Friday
night. It remains to be seen what kind of flash flood risk may
result with the latest WPC excessive rainfall outlook at slight (2
out of 4) for a good portion of Iowa. While the experimental
Hydrologic Ensemble Forecasting Service (HEFS) based on GEFS QPF
points to mainly within bank rises at the 10% chance exceedance
level, it will depend on where and how much rain falls in the
basins. This will ultimately determine whether a given river
response is a quicker rise, higher or prolonged crest, or a slower
fall.
Make sure to stay up to date on the latest forecasts and river
information, avoid flooded areas and rivers, and never drive around
barricades or through flooded areas.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
Heat Advisory until 7 PM CDT this evening for IAZ070-081-082-
092>094.
&&
$$
DISCUSSION...Cogil
AVIATION...Cogil
HYDROLOGY...Zogg
AREA FORECAST DISCUSSION
National Weather Service Wilmington OH
1024 PM EDT Tue Jun 25 2024
.SYNOPSIS...
Showers and thunderstorms are expected again Wednesday into
Wednesday night as a cold front moves through the Ohio Valley.
High pressure and a drier airmass will return for Thursday and
Friday.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
Showers and thunderstorms have exited southern portions of the
region leaving the area dry for the time being. Not expecting a
lot of development overnight, however what development there
will be is expected to be focused on the south and southwest
portions of the area. Temperatures are not expected to drop much
further overnight with lows generally in the upper 60s to around
70 degrees.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM THURSDAY/...
The mid level short wave will move east across our area through
the day on Wednesday, helping to push an associated cold front
southeast across the Ohio Valley. Developing low and mid level
flow ahead of this will lead to increasing moisture advection,
with fairly widespread showers and thunderstorms developing and
shifting southeast across the region through the day on
Wednesday. The strengthening wind fields ahead of this system
will lead to increasing deeper layer shear through the day with
the potential for some strong to severe storms ahead of the
front Wednesday afternoon and evening. However, depending on
how widespread and the effects of any morning pcpn, instability
may pose a limiting factor to a more widespread severe threat.
As of now, it appears the best chance for any severe storms
would be across southeast portions of our area where we should
have the best chance at some better instabilities. Highs on
Wednesday will range from the upper 70s in the northwest to the
upper 80s to around 90 degrees across our far southeast.
Showers and storms will taper off from the northwest Wednesday
evening as the cold front moves through. Lows Wednesday night
will be in the upper 50s to lower 60s.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
Surface high pressure will shift east through the Great Lakes
Thursday and Thursday night. This will provide cooler and drier
weather. As the high shifts off to the east on Friday, return flow
will bring low level moisture back into the Ohio Valley from the
south. A weak mid-level disturbance along with a surface warm front
could bring scattered storms into the region late Friday into Friday
night. However, the best chance for precipitation will arrive along
and ahead of the next cold front on Saturday. With PWATs near two
inches, will need to watch for a heavy rain threat. In addition,
heat indices could approach 100 degrees depending on cloud (and
precipitation) coverage and timing during the day.
More surface high pressure will follow this frontal system
Sunday into early next week, with temperatures falling back to near
normal values.
&&
.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
Some gusty winds with some light shower activity near KCVG and
KLUK at the start of the TAF period. There is quite a bit of
variability with convective development overnight and into the
day on Wednesday. Trended towards the HRRR as it is handling
current scenario better. Expect a period of dry conditions after
initial light shower activity around KCVG and KLUK, with some
shower activity moving into the region later in the overnight
hours. Cannot rule out some thunderstorms, however probability
was too low to include at this time. Going into the day on
Wednesday expect additional shower and thunderstorm development,
especially during the afternoon and into the early evening
hours. Limited mention to shra and vcts until confidence in
timing improves to time out tsra. Winds will pick up and some
wind gusts will also be possible during that time.
OUTLOOK...Thunderstorms possible Saturday.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...None.
KY...None.
IN...None.
&&
$$
SYNOPSIS...JGL
NEAR TERM...
SHORT TERM...JGL
LONG TERM...
AVIATION...
Area Forecast Discussion
National Weather Service Indianapolis IN
1021 PM EDT Tue Jun 25 2024
.KEY MESSAGES...
- Thunderstorms will be around at times today into Wednesday. Some
severe storms are possible, especially this afternoon.
- Severe storm chances remain overnight, but greater uncertainty
exists with timing and potential.
- Today will likely be the warmest day of the week.
- A brief respite from heat and humidity Thursday before another
warm up and additional storm chances this weekend.
&&
.FORECAST UPDATE...
Upstream convection continues to initiate over IA and W IL, but is
struggling to progress eastward as is encounters deep low level CIN
from an overturned atmosphere. The low levels should eventually
saturate and destabilize as a westerly LLJ increases overnight,
but this will likely take some time to come to fruition. For this
reason, thunderstorm and PoPs have been lowered significantly
through 08z, with a slow increase towards the morning hours
tomorrow.
&&
.MESOSCALE UPDATE...
Issued at 352 PM EDT Tue Jun 25 2024
A thunderstorm complex has recently entered central Indiana from
Illinois. In the past hour, these storms have evolved into an MCS
which has began propagating southeastward. Latest radar data has
shown a slight weakening trend within the past few scans, with the
strongest cell over Owen County as of 3:45pm.
Storms are advancing into an environment characterized by strong
instability (CAPE near 3000 J/Kg) and modest shear (25 to 35 knots).
A north-south CAPE gradient is found through the state of Indiana,
with diminishing instability as one heads east. Additionally, shear
decreases with southward extent.
Going forward, we can therefore expect that this system becomes
outflow dominant with time. Consequently, this likely leads to a
diminishing severe threat as well. However, soundings (ACARS and
model) show very deep CAPE profiles and steep lapse rates (7.5
C/Km). As such, occasionally strong updrafts may develop from time
to time as the system progresses southeastward. Strong wind gusts
and large hail are possible with the strongest cells.
Further north, a distinct outflow boundary is seen from Bloomington
Indiana eastward to the Ohio border. Very stable air exists north of
this boundary, characterized by CIN around -300 J/Kg. Storm
development north of this boundary is unlikely though lingering
stratiform rain is possible.
As a side note, additional storms are possible overnight as
instability advects back into the area behind the ongoing convective
system. Uncertainty remains with this, however, as ongoing
convection continues to alter the atmospheric thermodynamic profile.
&&
.SHORT TERM (This evening through Wednesday)...
Issued at 301 PM EDT Tue Jun 25 2024
We have a rather complicated short term forecast today due to
ongoing and expected convection.
THIS AFTERNOON
An MCS has been dropping south through the CWA this morning and into
the afternoon. Overall, a weakening trend has been observed with
most of the line dissipating completely. Two clusters, one near the
Ohio border and one just west of the Illinois border, remain.
The western cluster, currently near Charleston Illinois, or just
northwest of Terre Haute Indiana, is the most problematic for
central Indiana. As they propagate eastward, they will encounter an
increasingly unstable environment and further intensification is
likely.
MESOSCALE ENVIRONMENT
Across southwestern central Indiana, temperatures have climbed into
the upper 80s and lower 90s. Dew points are generally in the high
60s or lower 70s. Brisk southwesterly flow has been advection this
hot and humid air mass deeper into Indiana through the day. SPC
mesoanalysis shows upwards of 3000 J/Kg CAPE near Terre Haute.
Available CAPE decreases with eastward extent, with a distinct
instability gradient from Indianapolis down to Evansville.
ACARS soundings out of IND have shown an increasingly unstable air
mass with time. As of 18z, roughly 1800 J/Kg has been measured with
steep lapse rates of around 7.5 C/Km. The CAPE profile itself is
fairly wide, and extends to roughly 10km agl. This, combined with
DCAPE around 1000J/kg, would imply a wind and large hail threat.
Hodographs are short, with shear concentrated in the lower levels
(this may be from an outflow boundary that recently passed through
IND, however). SPC mesoanalysis shows less low-level shear south of
the boundary (under 20kt).
The aforementioned boundary extends from just north of Terre Haute,
southeastward through Martinsville, and then off into Ohio from
there. This boundary, with very unstable air located to its north,
may become a focused area for convective propagation as the Illinois
storm cluster builds eastward/southeastward. Additionally, storms may
preferentially propagate southwestward into the low-level flow. This
should lead to a generally south-southeastward system motion with
time, with areas north of the outflow boundary having less of a
chance of seeing strong to severe storms.
CONVECTIVE HAZARDS AND TIMING
Storms are ongoing just west of our border across Illinois, and
should be in our CWA within the hour. Terre Haute, for instance, may
see storms arrive between 3-4pm. Activity should then spread
southeastward, and potentially increase in speed if a mature cold
pool can develop. Latest HRRR shows storms exiting our area to the
southeast by around 8pm.
As for hazards, strong winds and large hail are the initial threats.
Should a cold pool develop, the threat will evolve into primarily a
wind threat. Additionally, training thunderstorms could lead to a
flooding threat.
TONIGHT
Guidance is insistent on storms redeveloping to our northwest
overnight and moving southeast into our CWA after midnight. This is
separate from the ongoing storms mentioned above. However,
uncertainty here is much greater due to the ongoing activity.
Current storms should thermodynamically alter the environment which
may change how subsequent storms develop and evolve. We will include
chance PoPs through the night which will be refined as the mesoscale
setup becomes clearer. Likewise, temperatures depend on how
convection develops but most locations will see lows in the high 60s
overnight.
WEDNESDAY
Tomorrow looks to be a cooler and cloudier day as a mid-level vort
max (and associated surface reflection) moves across central
Indiana. As moisture continues to advect into the region overnight,
precip chances will increase and become widespread due to the
synoptic scale forcing associated with the system. We will cap
precip chances at 80 percent due to the scattered convective nature
of the precipitation. Severe weather is not expected due to lower
shear and lower instability, but a low probability flooding threat
may remain.
&&
.LONG TERM (Wednesday night through Tuesday)...
Issued at 301 PM EDT Tue Jun 25 2024
Wednesday night through Thursday night...
The long term period will start off quiet and pleasant as surface
high pressure builds in behind a cold front settling south of the
region. Look for temperatures to remain near or slightly below
normal with weak cold air advection in place. Temperatures should
range from the upper 70s to low 80s for most areas. Far southern
counties may warm up into the mid 80s. Lower humidity on top of the
cooler temperatures will feel quite refreshing compared to the
hotter temperatures this past week. Expect light winds during this
period due to a weak pressure gradient.
Friday through Saturday...
Much of the day Friday is expected to remain quiet with surface
ridging in place initially. Late Friday into Saturday a surface low
and parent trough will move through the region with rain and storms
likely. The best chance for precipitation should be during the
Saturday once the cold front approaches. Daytime heating and
increasing moisture advection ahead of the front is expected to
promote moderate destabilization. This combined with weak to modest
effective bulk shear may support a few strong to severe storms. The
primary threat would likely be isolated damaging wind gusts, but
localized flooding or severe hail cannot be ruled out. Increasing
S/SW flow ahead of the aforementioned system will lead to warming
temperatures. Highs are likely going to be in the upper 80s to low
90s by Saturday.
Saturday night onward...
Precipitation chances linger overnight Saturday before drier
conditions return Sunday as the aforementioned cold front exits the
region. Surface high pressure building in should provide mundane
weather conditions Sunday and Monday along with cooler temperatures
from cold air advection.Another system may approach by Tuesday
bringing additional chances for precipitation, but diverging model
solutions leads to low confidence in this potential.
&&
.AVIATION (00Z TAF Issuance)...
Issued at 707 PM EDT Tue Jun 25 2024
Impacts:
- Thunderstorms possible after 04Z tonight. Greatest Confidence over
KHUF
- Additional thunderstorms possible tomorrow from 14Z through 00Z
- Potential for MVFR or worse conditions in thunderstorms, VFR
conditions likely outside storms
Discussion:
Low-moderate forecast confidence due to uncertainty in convective
development through tonight, as each round of convection will have
an impact on the next.
A cluster of storms currently over central IL will continue to
organize and move towards central Indiana. These storms could
potentially impact all TAF sites between 04-10Z overnight. There is
potential for MVFR or worse conditions in any thunderstorms. Outside
of convection, VFR conditions are expected.
More thunderstorms are expected to develop ahead of a boundary
tomorrow, with periods of MVFR or worse conditions within storms.
Following boundary passage winds will quickly shift towards NNW/N.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE...Updike
SHORT TERM...Eckhoff
LONG TERM...Melo
AVIATION...Updike
Area Forecast Discussion
National Weather Service Louisville KY
928 PM EDT Tue Jun 25 2024
.KEY MESSAGES...
* Isolated to scattered showers and storms will be possible into
the evening. A few storms may be strong to severe with locally
damaging wind the main threat.
* Better shower and storm chances arrive Wednesday, bringing much
needed rain to the region. A few storms may produce locally
enhanced gusty winds and hail.
* Above-normal temperatures into next week with chances of shower
and storms returning this Saturday.
&&
.UPDATE...
Issued at 928 PM EDT Tue Jun 25 2024
Previous convection has largely dissipated and/or pushed east of the
Bluegrass Region. We do have one small cluster of storms approaching
Ohio and Butler counties this evening, which could produce brief
heavy rainfall, gusty winds, and lightning. Isolated small hail is
also possible if the current storm in far eastern Hopkins County can
hold together.
The previous convective outflow boundary is now approaching the TN
border, leaving much cooler sfc temps and a low-level inversion in
its wake. We are now in a lull in convective activity, but
additional isolated to scattered showers/storms are possible during
the early morning hours of Wednesday. Any activity overnight should
be pretty spotty, but a slight uptick in coverage is possible by 06-
12Z with a developing 25-30 kt SW LLJ. The best chance for rain for
most will be tomorrow as the upper level trough swings overhead and
the sfc cold front pushes into southern IN and central KY.
Rain/thunderstorm chances peak during the afternoon and evening
hours, when storms will be capable of locally heavy rain, isolated
damaging winds, and frequent lightning.
Issued at 613 PM EDT Tue Jun 25 2024
A weakening line of storms has pushed southeast through most of
southern Indiana and is now into portions of north-central Kentucky.
An outflow boundary continues to race several miles ahead of the
rain. Wind gusts between 30-50 mph have been reported along the
outflow boundary. Expect winds to remain quite gusty along the
outflow as it continues to sink south into a very warm airmass
characterized by steep low-level lapse rates, high LCLs, and high
DCAPE.
The strongest convection at the northeastern-most part of the line
may have produced sporadic wind damage/severe gusts in Scott,
Jefferson, and Clark counties in Indiana. However, this portion of
the line has also weakened but continues to produce heavy rainfall,
quite a bit of lightning, and gusty winds. The KY Mesonet station in
northern Oldham County recorded a wind gust of 53 mph.
Thunderstorms are forecast to continue to gradually weaken in
intensity through the evening over central Kentucky. Widespread
gusty winds of 30+ mph out of the N/NW are likely along the gust
front.
Issued at 432 PM EDT Tue Jun 25 2024
Strong line of convection from just south of Bloomington to near
Vincennes is pushing southeast into southern Indiana. Most of the
line is outflow dominant, with the VWX radar showing a well-defined
outflow boundary quickly approaching northern Gibson, Pike, Dubois,
and Orange counties. These storms are likely to be sub-severe as
they sink toward Dubois and Orange counties.
The northeastern-most part of the line that passed through
Bloomington produced a 79 mph wind gust at KBMG! This severe storm`s
outflow is more coincident with the leading edge of the updraft
towers and has a better chance of producing locally severe wind
gusts downstream through Jackson County and into our northern CWA -
northeastern Washington Co, Scott Co, and Jefferson Co IN.
&&
.SHORT TERM /THROUGH TONIGHT/...
Issued at 308 PM EDT Tue Jun 25 2024
Latest forecast update focuses on the convective chances later this
evening into the overnight. As of the early afternoon, convection
ongoing across IN/IL will be the focus as storms continue to
progress along the cold frontal boundary and pushing southward
toward the forecast area. While environmental shear parameters are
weak, plenty of CAPE and steep low level lapse rates are
present across the area according to the latest high resolution
model soundings. Latest HRRR run has convection moving into the
region between 6 PM and 9 PM EDT this evening, with a break and
then another chance for rain through Wednesday. Wednesday is
the best chance for accumulating rainfall from 0.25 to 1.25 of
rain through Wednesday evening.
&&
.LONG TERM /WEDNESDAY THROUGH TUESDAY/...
Issued at 308 PM EDT Tue Jun 25 2024
Synopsis...The medium range forecast will feature well above-normal
temperatures and at least two waves of rainfall/storms: this weekend
and again by the middle of next week. Initially, mid-level pattern
will showcase shortwave trough with broad cyclonic circulation over
the Eastern CONUS, large blocking high centered over the Southwest
with ridge extending northward across the Rockies and finally a
strong upper low entering through the Pacific Northwest. During the
next coming days leading into the weekend, the mid-level high will
progress to the east and build across the South and Mid Atlantic as
the Eastern shortwave trough ejects to the Atlantic. Meanwhile, the
upper-low will continue moving eastward along the northern third of
the Lower 48 with as it experiences gradual weakening and evolves
into an open shortwave. Nonetheless, this wave will be responsible
for increasing rain/storm chances over the weekend as the
accompanying front rushes through the region. For next week, mid-
level high will remain stationary along the southern half of the
CONUS while the northern-stream branch of the jet stays active with
continuous shortwave energy pulses.
Model Evaluation/Confidence...There is fairly good confidence in the
synoptic pattern evolution going into the weekend as the 25/0Z
deterministic guidance show a very similar evolution of this weekend
shortwave trough and the timing of the frontal wave. On the other
hand, uncertainties exist on the severe weather probabilities this
Saturday afternoon/evening as pre-frontal/frontal convection could
overlap with best daytime instability and slightly enhanced low- to
mid-level flow to yield a low chance of damaging winds and hail.
There is some support behind that reasoning from the latest two runs
of the CSU ML algorithm. Overall, forecast confidence decreases next
week, especially regarding the timing of precipitation from
Wednesday and onwards. So far, there has been consistency between
the ECWMF and GFS in representing the mid-level stationary high
retrograding to the west and allowing vorticity energy under NW flow
aloft to move across the OH Valley. Conversely, the CMC is slower
and less amplify, so it keeps the high/ridge extended a longer
period over the forecast area.
Thursday - Friday...Most of the convective activity from Wednesday
should be moving out of the area Wednesday night with quick drying
of the column and mid-level strong subsidence accompanying the
building mid-level high and a surface high pressure transitioning
along the Great Lakes. Therefore, expect mostly sunny conditions on
Thursday with north to northeast surface winds. Although highs on
Thursday afternoon will still be in the mid to upper 80s, dewpoints
will decrease a few degrees providing a slight relief from the heat.
Quick moisture recovery will occur on Friday as winds shift to the
south and temperatures surge back up to the low 90s. Friday is still
being advertised as a dry day but mid to upper clouds will
overspread the Lower Ohio Valley.
Weekend...Above-normal temperatures and increasing rain chances will
be the headlines this weekend as the region falls on Saturday in the
warm sector of the next storm system. First, muggy conditions are
anticipated on Saturday with highs around the mid 90s and dewpoints
in the lower 70s. If the precipitation forecast verifies in the late
afternoon and early evening, then there is a chance for heat indexes
to stay in the low triple-digits for several hours. Showers and
storm will most likely arrive late in the afternoon and early
evening with a non-zero chance of marginally severe weather (as
explained above). Besides chances of strong to severe storms, it
would very beneficial to have scattered rainfall totals of a quarter
to half an inch across the region to mitigate some the long-term
precipitation deficits and drought concerns.
Next Week...Above-normal temperatures and mostly dry weather will be
found at the beginning of the week with a wetter outlook by the
second half of the week (including the 4th of July). Nonetheless,
forecast confidence remains relatively low on any potential scenario.
&&
.AVIATION /00Z TAFS THROUGH 06Z FRIDAY/...
Issued at 756 PM EDT Tue Jun 25 2024
Weakening scattered convection continues to sink southeast in
central KY, and RGA will begin the period with VCTS. BWG could see a
few showers in the vicinity, but confidence is lower in southern KY.
The showers and storms continue to gradually diminish. Expect
relatively dry conditions overnight with light winds.
Scattered to numerous showers and storms are likely for Wednesday as
a cold front approaches from the northwest. Winds will initially
increase out of the southwest on Wednesday before veering
northwesterly in the wake of the front toward the end of this TAF
period. Largely VFR conditions will prevail outside of
thunderstorms.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...None.
IN...None.
&&
$$
UPDATE...EBW
SHORT TERM...MCK
LONG TERM...ALL
AVIATION...EBW
Area Forecast Discussion
National Weather Service Marquette MI
629 PM EDT Tue Jun 25 2024
.KEY MESSAGES...
- Gusty winds up to 40 mph across the Keweenaw into early
evening.
- Pattern remains active, especially from late week into early
next week, with yet more rounds of showers and storms
&&
.SHORT TERM /THROUGH TONIGHT/...
Issued at 343 PM EDT Tue Jun 25 2024
Water vapor imagery and RAP analysis show that the convectively
enhanced shortwave that brought shra/tsra to the area last night is
over Georgian Bay. Another shortwave trof extends from James Bay to
nw of Lake Superior and a third shortwave is over southern
Saskatchewan. At the sfc, a trof extends across eastern Lake
Superior and central Upper MI, and a cold front extends from James
Bay to just nw of Lake Superior. Rapidly deepening mixed layer to
the w of the sfc trof is leading to sharp drying this aftn as sfc
dwpts are plummeting into the mid 40s to lwr 50s F across western
Upper MI. To the e, sfc trof and lake breeze development off of Lake
Superior has led to a few shra developing recently.
For the next couple of hrs, expect isold shra over the eastern fcst
area ahead of sfc trof/lake breeze. Otherwise, dwpts will continue
to fall from w to e in the wake of passing sfc trof, leading to more
comfortable conditions under temps in the mid 70s to mid 80s F.
Across the Keweenaw, fcst soundings suggest wind gusts to around 40
mph over the next several hrs. Wouldn`t be surprised to see a few
gusts to around 45 mph for a couple of hrs based on winds at top of
mixed layer. Otherwise, wind gusts of 20-30mph will be fairly common
over roughly the w half of Upper MI.
Cold front approaching Lake Superior will drop s across the area
later this evening/overnight. Other than a wind shift to n to ne, it
should pass uneventfully given the drying that is currently
underway. Expect clear to partly cloudy skies thru the evening. Late
tonight, attention turns to shortwave currently over southern
Saskatchewan. This wave will reach nw WI/western Lake Superior
around 12z Wed. Given the decent, small cluster of shra currently
associated with this feature, models seem on track bringing shra
into nw Upper MI in the 10-12z timeframe. Cold front that drops into
the area tonight will be aligned from northern MN se thru northern
WI early Wed morning, and that should also provide some focusing of
forcing as well due to weak waa over the boundary in response to the
wave. Temps tonight will fall back to the mid 40s to mid 50s F.
&&
.LONG TERM /WEDNESDAY THROUGH TUESDAY/...
Issued at 320 PM EDT Tue Jun 25 2024
An inverted trough along a descending cold front from northern
Ontario moving through the U.P. Wednesday looks to bring some light
rainfall across mainly the Keweenaw during the morning hours before
degrading throughout the day and only bringing slight rain chances
to the east and south central later in the day. As high pressure
ridging builds in from our west throughout the day, expect the cloud
cover to dissolve away with time Wednesday. However, with fairly
cool temps aloft moving over us in association with the ridging
moving in and the cold air advection behind the front (4-6C), highs
Wednesday should be limited to the 60s inland and the mid 50s to
around 60 along the Lake Superior shoreline. With ridging continuing
to build into the Upper Great Lakes Wednesday night, expect clear
skies, allowing temperatures to plummet in the interior areas; some
spots could get into the mid to upper 30s or lower. That being said,
given the drier air moving in, no frost is expected to form over the
interior areas Wednesday night.
Calm weather continues Thursday as the high pressure ridging peaks
over us during the morning hours. More active weather looks to
return late Thursday night/Friday as a low lifts off of the Rockies
through the Canadian Prairies/Northern Plains into northern Ontario.
Along the cold front moving through Friday through Saturday expect
some showers and thunderstorms. In addition, a shortwave low
rotating around the low pressure system could bring additional light
rain shower activity (that`s possibly upslope enhanced) late
Saturday into possibly Sunday morning behind the cold front. With
MUCAPE between 500-1500 J/kg ahead and along the cold front and 0-6
km bulk shear around 40 to 50 kts, there is a non-zero chance that
we could see some severe weather as the cold front passes.
More quiet weather returns early next week as yet another high
pressure ridge moves overhead. Behind it, another low pressure
lifting through the Canadian Prairies looks to bring more rain
showers and thunderstorms to end the extended period. Overall,
expect temperatures around normal for the next several days, with
showers and thunderstorms coming and going every few days.
&&
.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 628 PM EDT Tue Jun 25 2024
VFR will prevail at IWD/CMX/SAW through tonight. Winds will diminish
toward sunset and then veer n to ne. In the 09z-12z timeframe, low
clouds (MVFR cigs) will arrive at all terminals. A few shra may also
occur at CMX btwn 11-14z. The MVFR cigs at CMX and SAW that form in
the late morning will scatter out to VFR at CMX/SAW during the aftn.
&&
.MARINE...
Issued at 320 PM EDT Tue Jun 25 2024
The last of the patchy fog over the eastern lake ends late this
afternoon/early this evening as a cold front descends from northern
Ontario this evening into Wednesday. As this happens, the southwest
to west winds of 25 to 30 knots across the lake this afternoon die
down to 20 knots or less behind the cold front. The light winds look
to continue Wednesday to Friday morning as high pressure ridging
moves over the region. Once we get into Friday, thunderstorms look
possible over the lake again as a low pressure lifting from the
Rockies moves towards northern Ontario. Currently, thunderstorms
look possible Friday through Saturday; as of right now, there is a
non-zero chance of severe weather. In addition to the thunderstorms,
winds pick back up to around 20 knots from the southeast Friday as
the low`s center approaches. With the surface low looking to move
through Lake Superior Friday night/Saturday, we could see winds
shift suddenly and sharply near the center of the low. Behind the
low, expect winds from the north and northwest to pick to 20 to 25
knots across the lake. That being said, if the cold air advection
behind the low is strong enough, we could see gusts up to 30 knots
or even gales (see the 12z run of the GFS for an example). These
stronger winds look to die down to 20 knots or less again by
Saturday night as ridging starts building back in once again over
the region. The light winds continue Sunday into next Monday as high
pressure ridging dominates the Upper Midwest.
&&
.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...Rolfson
LONG TERM...TAP
AVIATION...07
MARINE...TAP
Area Forecast Discussion
National Weather Service Nashville TN
814 PM CDT Tue Jun 25 2024
...New UPDATE...
.UPDATE...
Issued at 806 PM CDT Tue Jun 25 2024
A line of thunderstorms over northern KY are pushing towards the
south, with an outflow boundary beginning to move into northern
Middle TN. Watching this line of thunderstorms closely, but CAMs
are adamant that this will break up before they reach our area.
Introduced some small PoPs across the northwest late this evening
just in case these thunderstorms do hold together. But the rest of
the forecast remains on track with better storm chances during the
afternoon tomorrow as an upper-level trough swings through the
area with a few of these storms potentially becoming strong to
severe with damaging winds the primary threat.
&&
.SHORT TERM...
(Rest of today through Wednesday)
Issued at 1137 AM CDT Tue Jun 25 2024
Toasty but fairly unhumid day across the midstate with current
temperatures in the mid 80s to low 90s but dewpoints down in the
upper 50s to low 60s. This drier airmass along with ample sunshine
will allow highs to soar into the mid to upper 90s today west of
the Plateau. Deeper low level moisture is lurking just southwest
of our cwa and will begin moving back into the area later today,
and as a result the HRRR and CONSShort models show a couple of
popup showers or maybe a thunderstorm late this afternoon or
evening - mainly in our southwest counties. Therefore added a
very slight chance pop based on this potential.
Tomorrow continues to appear to be our best rain chances over the
next 7 days as an upper trough swings down from the north,
forcing a cold front across the region. Guidance varies wildly on
coverage and timing of showers and storms tomorrow, but in
general highest precip chances will be during the afternoon with
high likely pops warranted. Temperatures will be a challenge
tomorrow especially if there are considerable clouds and rain
during the morning, but otherwise should be a another hot and
humid day with highs well into the 90s. Forecast soundings are
all over the place with the NAM its usual aggressive self, but
consensus is around 1000-1500 J/Kg MLCAPE with mid level lapse
rates between 5-6 C/Km and deep layer shear near or less than 20
knots. These parameters, while not very impressive, would still
be favorable for a few storms to become strong or possibly severe
with damaging microburst winds the main threat. If storms can
congeal into clusters or lines as the NAM suggests, there could
be a bit higher potential for damaging winds, but this is
uncertain. SPC continues to highlight our forecast area in a
marginal risk for tomorrow, which seems quite reasonable.
&&
.LONG TERM...
(Wednesday Night through next Tuesday)
Issued at 1137 AM CDT Tue Jun 25 2024
Rain chances will end on Thursday and a much cooler and less
humid day is anticipated, with highs only in the mid 80s to
around 90. This cooldown will be unfortunately brief as an upper
ridge builds across much of the southern US into the weekend.
Highs will reach the mid to upper 90s for much of the midstate
Friday and Saturday with potential for a few spots to hit 100. In
addition, low level moisture is expected to be higher than we
have seen recently with dewpoints in the mid 60s to low 70s,
which will bring max heat index values in the afternoons to around
the 105 mark on Friday and between 105-110 on Saturday.
Therefore, a Heat Advisory may be needed for parts of the midstate
on Friday and likely all of the area for Saturday. By Saturday
night into Sunday, another cold front will sink southward from the
Midwest and bring slightly cooler temperatures as well as another
round of scattered showers and storms. Coverage of this round of
rain doesn`t appear as widespread as Wednesday, so only chance
pops are currently warranted. After that, forecast is basically
rinse and repeat with a return to highs in the upper 90s by early
next week.
&&
.AVIATION...
(00Z TAFS)
Issued at 651 PM CDT Tue Jun 25 2024
VFR conditions this evening with light winds. Showers move through
Middle TN Wednesday morning and then again Wednesday afternoon.
Expect lowering of CIGs and VIS with any strong storms that
develop along with gusty winds.
&&
.PRELIMINARY POINT TEMPS/POPS...
Nashville 74 96 71 90 / 10 60 60 10
Clarksville 74 91 69 88 / 20 70 60 0
Crossville 66 92 65 84 / 10 40 70 10
Columbia 71 97 69 89 / 10 50 60 10
Cookeville 69 93 67 84 / 10 50 70 10
Jamestown 69 92 66 83 / 10 40 70 10
Lawrenceburg 71 96 69 88 / 10 50 60 10
Murfreesboro 70 98 69 89 / 10 60 70 10
Waverly 74 92 69 88 / 10 70 60 10
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE.......Clements
SHORT TERM...Shamburger
LONG TERM....Shamburger
AVIATION.....Cravens
Area Forecast Discussion
National Weather Service Phoenix AZ
515 PM MST Tue Jun 25 2024
.UPDATE...Updated 00Z Aviation Discussion.
&&
.SYNOPSIS...
Enhanced monsoonal moisture across the region will continue to
allow thunderstorm chances to persist into the weekend, overall
coverage will decrease and be confined mostly to the higher
elevations. Temperatures will continue to run several degrees
above normal, so hot and humid conditions will persist as well
during this period.
&&
.DISCUSSION...
The early afternoon radar and satellite imagery showing the usual
midday showers and thunderstorms forming over the high country
north and east of Phoenix with the exception of an isolated storm
across far southern Maricopa County. Visible satellite imagery
has been showing a remnant MCV from overnight convection drifting
northwest across the SC AZ through the morning. This has resulted
in overall increased cloud cover for most areas and keeping
conditions more stable. The latest SPC Meso analysis subsequently
showing convective inhibition persisting across the Phoenix valley,
unlike yesterday when we had full sunshine and eroded the cap.
For the rest of today, the latest HRRR convective trends seem
reasonable given the aforementioned instability trends. Most of
the convection should remain over the high country with a steering
flow to the north and away from the Phoenix area. An exception is
likely into western Maricopa County into La Paz County ahead of
MCV where more insolation has occurred and cap has eroded.
Forecasting some convection to develop in these areas into early
this evening.
Shower and storm potential does try to trend downward as upper
level ridge retrogrades into AZ/NM region this week, which should
tend to inhibit convection, especially for the lower deserts.
HRRR hints at this trend on Wednesday. Also, by Thursday and
Friday, watching a stronger trough dig across the northern
Rockies, which will break down the ridge over AZ and also shunt
deeper moisture to the south with the development of a drier
west/southwest flow. This should further inhibit storm potential
and confine it to mainly far SE and Eastern AZ into first half of
the weekend.
After this trough passes to the northeast, ridge builds again
across the SE U.S. which will bring back the southerly flow and
moisture that is poised to move back north into the region as
early as Sunday. This will increase storm chances again into next
week. CPC outlooks for 8-14 days (the first week of July) favors higher
percentages for above normal precipitation.
As for temperatures, readings will remain above normal by several
degrees, but nothing on the record/extreme level. This will
maintain a consistent moderate HeatRisk across the region through
the period.
&&
.AVIATION...Updated at 0000Z.
South-Central Arizona including KPHX, KIWA, KSDL, and KDVT:
The main aviation concern this evening will be the timing and wind
shifts of any outflow boundaries that move through the Phoenix
Metro. There are currently multiple outflows moving out of the
north. These outflows are expected to reach KDVT and KSDL around
02-03Z. Confidence is low that these outflows will reach KPHX and
KIWA, however, if they are able to reach these terminals it would
be around 03-05Z. These outflows will cause a wind shift to more
northerly. There are outflows from the NW and NE, but it is
uncertain at this time which one will dominate. Behind these
outflows winds will likely stay out of the north before going
light and variable during the overnight hours. Westerly winds will
redevelop by the mid-to-late morning time tomorrow. Occasional
gusts near 20 kt is also expected tomorrow afternoon. SCT-BKN mid
and high level clouds will continue through the TAF period as
well.
Southeast California/Southwest Arizona including KIPL and KBLH:
Winds will follow their typical diurnal patterns. There may be
some occasional gusts around 20 kt this evening at KIPL from
02-05Z. Gust near 20 kt are expected at KBLH again tomorrow
afternoon. The one thing to watch for this evening will be any
outflow boundaries reaching KBLH from the activity to the
northeast of the terminal that is in west-central AZ. The
potential timing of an outflow boundary looks to be between 05-07Z
and it would switch the winds to be northeasterly.
&&
.FIRE WEATHER...
Monsoonal moisture will continue to result in daily chances for
shower and thunderstorm activity. The higher terrain areas will
see the greatest potential with some locally heavy rainfall with
any storms that develop. Best chances for storms are today, with a
gradual decrease in chances/coverage through Friday, where chances
drop around 15% or lower. Chances for wetting rains will
generally remain around 10-20% for the higher terrain areas and
5-10% for the lower deserts of south-central Arizona today, before
dropping below 10% across the region starting Thursday. With the
elevated moisture in place, MinRH values through the middle of
this week will range between 30-40% across the far eastern
districts to between 15-25% across the western districts before
slowly drying during the latter half of this week. Winds will
follow their typical daily tendencies, with gusty outflows from
any thunderstorm activity anticipated over the next several days.
Temperatures average several degrees above normal through the
forecast period.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&
$$
DISCUSSION...Frieders
AVIATION...Berislavich
FIRE WEATHER...Young/Frieders
Area Forecast Discussion...UPDATED
National Weather Service Springfield MO
906 PM CDT Tue Jun 25 2024
.KEY MESSAGES...
- Daily high temperatures in the upper 80s to upper 90s through
this week, with Heat Index values ranging in the 90s and into
the 100s, especially Friday into the weekend.
- Scattered thunderstorm chances tonight into Wednesday, with
highest chances (50 to 80%) after midnight. Slight risk for
severe weather for the majority of the area with damaging
winds the main threat.
&&
.MESOSCALE...
Issued at 837 PM CDT Tue Jun 25 2024
00z KSGF sounding measured a very moist and unstable airmass
with 4000j/kg of MU CAPE, 0 CIN and PW values of 1.80in. A
cluster of thunderstorms has continued to affect the Rolla/Vichy
area with a general southerly direction. This activity will
continue dropping south and affect areas along and east of the
Highway 63 corridor through 11pm. Overall the severe threat is
low with this activity. A lone storm has continued to move east
along the KS/OK border and may try to move into southeast
Kansas. Slightly higher shear out there could allow for it to
remain severe and will monitor that storm for the next few
hours.
Of greater concern for the overnight hours is the development of
severe storms currently across Nebraska and Iowa. These storms
are developing along a frontal boundary within a higher sheared
environment. Latest 00z HRRR and last few WOFS runs indicate
that these storms will continue to merge/conglomerate and
develop cold pools as they move south, following propagation
vectors. Therefore, expect at least a few clusters of storms or
line segments to move towards the KC metro and then into our
area generally late, after midnight. There also appears to be a
weak low level jet that develops across Kansas and Oklahoma with
some development of storms likely in a north to south corridor
on the edge of this jet. This could occur closer to the
Missouri/Kansas border area ahead of the incoming storms. Given
the high instability and weak inhibition storms just need a
trigger and other isolated storms could develop across the rest
of the CWA before the main batch of storms arrives late.
That main batch of storms look to arrive along the I-44
corridor between 3am-7am and continue to move southeast from
there in the morning. Given the amount of instability and
moisture, damaging winds of 60-70 mph is the most likely hazard.
Frequent lightning will also be a concern. The flooding threat
looks to be limited given the progressive nature of the storms
and the dry conditions lately however any areas that see slower
moving or repeated storms could see localized flooding. Those
outdoors tonight will need to remain weather aware given the
damaging wind potential.
&&
.SHORT TERM /THROUGH TONIGHT/...
Issued at 153 PM CDT Tue Jun 25 2024
We have 3,000-4,500 J/kg of SBCAPE across the area this
afternoon as weak shortwave energy passes through, which will
result in isolated pop-up showers and storms into this evening.
Shear is very weak, so storms will be pulsey and disorganized.
No severe weather is expected with this convection.
Heat is obviously an issue this afternoon with temperatures in
the mid 90s and dew points in the mid to upper 70s as of 2pm,
resulting in heat index values
Additional, potentially severe, convection is then likely
tonight. Storms are expected to develop across western Iowa,
then grow upscale and move southward through the night.
Additional storms may develop ahead of the complex. The main
concern is with the MCS activity, where a damaging wind threat
of 60-70mph is the primary concern. This may linger in the
morning hours on Wednesday, but models vary by a few hours on
timing, placement, and strength, which limits confidence in
specific details.
Highs on Wednesday should be cooler with highs in the mid 80s to
low 90s currently expected, but that will be highly dependent on
convective evolution. Could be cooler or warmer if precip/cloud
stick around longer or dissipate more quickly.
&&
.LONG TERM /WEDNESDAY THROUGH TUESDAY/...
Issued at 153 PM CDT Tue Jun 25 2024
Thursday will be another "cooler" day with highs in the mid 80s
to low 90s, but heat builds back in on Friday. Friday highs are
forecast to range from the low to upper 90s with max heat index
values from the upper 90s to around 105.
We see a return of area-wide PoPs Saturday into Saturday night
as a cold front may move through. There severe weather potential
is not clear right now, but does not appear to be too great.
Look for highs in the upper 80s to mid 90s Saturday, which may
change if the timing of the front and convection changes. Sunday
should be cooler with highs in the 80s and 20-40% chances for
precip.
The repetitive cycle of jumping right back to heat continues
early next week with highs in the 90s for Monday and Tuesday.
Could see a need for more heat advisories if this verifies.
&&
.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 627 PM CDT Tue Jun 25 2024
VFR conditions are expected this evening through the overnight
hours with southerly winds. There is a 20 percent chance of
thunderstorms this evening however higher chances still look to
move in after 09z however given the uncertainty have kept prob30
groups in for now. As confidence in timing increases we will
then include tempo groups. Low level wind shear is possible at
SGF and JLN. Winds then turn more northwesterly for Wednesday.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
KS...None.
MO...None.
&&
$$
MESOSCALE...Burchfield
SHORT TERM...Melto
LONG TERM...Melto
AVIATION...Burchfield
Area Forecast Discussion...UPDATED
National Weather Service Shreveport LA
1017 PM CDT Tue Jun 25 2024
...New UPDATE...
.UPDATE...
Issued at 1002 PM CDT Tue Jun 25 2024
Diurnally-driven convection had dissipated for tonight across the
forecast area. Our attention turns to the north to the storms
ongoing across Central Oklahoma. Most of the model guidance keeps
these storms just to our west before dissipating during the early
morning hours. However, I did maintain slight chance PoPs in
Southeast Oklahoma during the hours before sunrise.
The bigger question surrounds any convection and its affects on
temperatures and heat index values for tomorrow. Much of the
guidance suggests the storms will hold off until late in the
afternoon, but the HRRR bring a weakening complex southward across
the area during peak daytime heating to near the Interstate 20
corridor by mid afternoon. If the convection does not arrive until
late afternoon or early evening, peak heat index values should
easily rise above advisory criteria areawide. If the storms arrive
earlier in the day, it may be more uncertain. If the HRRR
verifies, heat indices should warm to at least 105 degrees F for
areas south of a line from Mineola TX to Farmerville LA. Farther
north, there could be just enough time for temperatures and
humidity levels to recover to advisory criteria.
Given our current conditions and past trends, warming typically
occurs very quickly. Given the factors above, and after
collaboration with neighboring WFOs, a Heat Advisory has been
issued for Wednesday from 15z-00z (10 AM to 7 PM CDT).
CN
&&
.SHORT TERM...
(This evening through Thursday)
Issued at 311 PM CDT Tue Jun 25 2024
Heat Advisory criteria (heat indices of 105-110 degrees) has been
met as of mid-afternoon over all but the Wrn sections of E TX,
but this too should verify over the next couple of hours once
temps top out in the mid to upper 90s. As expected, limited mixing
though over Srn AR/NCntrl LA has maintained mid 70s dewpoints
over these areas, as low level moisture pooling continues farther
to the E across the Lower MS Valley along the W side of a
stationary front that persists from the Mid-South region into
NCntrl MS/SW and Srn Al. This has resulted in heat indices near
110 degrees over these areas, and may briefly reach Warning
criteria before daytime heating diminishes late this afternoon.
Will allow the Heat Advisory to ride as is for the entire region
through 00Z Wednesday. All remains quiet too as the afternoon
visible satellite has maintained a relatively flat cu field over
the region. The exception has been over ECntrl LA/SCntrl AR where
the cu is a bit more agitated, with isolated convection possible
over these areas through 00Z before diminishing with the setting
sun.
Much if not all of the overnight hours should remain quiet across
the region tonight, although the transition to NW flow aloft may
yield some unsettled weather courtesy of shortwave energy progged
to drop SE into the region late, along the Ern periphery of the
upper ridge centered from the Desert SW into W TX. In fact,
various short term progs suggest that convection will initiate by
early evening over NW OK along the lead shortwave trough axis, but
should gradually weaken through late evening with reduced forcing.
However, the GFS is a lone outlier dropping a potential MCS SE
into the region by and after daybreak Wednesday, maintaining the
convection through much of the day. Not quite buying this solution
yet given the lack of other model support, with the potentially
more feasible compromise in solutions suggesting that convection
will be later to develop over Nrn AR Wednesday morning along a
weak sfc front and attendant shortwave trough that will drop SE
through the Mid-South and Lower MS Valley. Again, considerable
timing variabilities exist with convection eventually building S
into the region by afternoon, which could impede heating and
potential Heat Advisory criteria being met again.
After collaborating with adjacent WFO`s, have opted to defer the
issuance of a Heat Advisory to the mid shift, as hopefully better
model agreement will come into play with regards to the convection
timing. Do believe that one will be needed for at least portions
of E TX/N LA, but would rather avoid potentially flip flopping the
forecast with the potential heat headlines. Did maintain chance
pops though for Srn AR/N LA, which could linger during the evening
before diminishing. This convection could reinforce the sfc bndry
SSW into the area by Thursday, which would only result in
additional moisture pooling over the region just as the upper
ridge begins to expand back S into AR/LA by afternoon. Thus, heat
products will likely be needed again areawide Thursday, with some
consolation that isolated to scattered convection will remain
possible near the stationary front.
15
&&
.LONG TERM...
(Thursday night through next Monday)
Issued at 311 PM CDT Tue Jun 25 2024
The ridge aloft will continue expanding E across the Lower MS
Valley Thursday night, but remain relatively flat before
amplifying further this weekend into much of next week. Thus, the
extreme heat is on as more expansive areas of triple digit temps
are expected through the remainder of the long term period. Heat
Headlines will be needed through the remainder of the period, with
very limited relief expected at night as temps struggle to fall
to/just below 80 degrees. Still can`t rule out the potential for
isolated diurnal convection over portions of the area, but believe
that wetting rains will be hard to come by and will do very little
to the continued drying conditions in place.
15
&&
.AVIATION...
(00Z TAFS)
Issued at 600 PM CDT Tue Jun 25 2024
For the 26/00z TAF update...Radar imagery is showing some showers
and thunderstorms moving through south central and central
Arkansas this evening. Not anticipating any impacts at this time
to KELD so I have left all mention out and will amend if needed.
Otherwise some fair weather CU around 5k feet prevail for most of
the region. Ultimately things should clear out for all terminals
during the overnight hours with some low clouds moving in again
towards morning. There is some potential for some MVFR conditions
again tonight for KLFK. /33/
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 80 97 77 96 / 10 20 20 20
MLU 78 96 73 93 / 10 40 30 40
DEQ 75 95 73 93 / 10 40 20 10
TXK 80 98 75 96 / 10 30 20 10
ELD 75 94 71 91 / 10 40 30 20
TYR 79 97 77 98 / 0 20 20 10
GGG 78 96 77 96 / 0 20 20 20
LFK 76 96 77 97 / 0 20 20 20
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...Heat Advisory from 10 AM to 7 PM CDT Wednesday for ARZ050-051-
059>061-070>073.
LA...Heat Advisory from 10 AM to 7 PM CDT Wednesday for LAZ001>006-
010>014-017>022.
OK...Heat Advisory from 10 AM to 7 PM CDT Wednesday for OKZ077.
TX...Heat Advisory from 10 AM to 7 PM CDT Wednesday for TXZ096-097-
108>112-124>126-136>138-149>153-165>167.
&&
$$
SHORT TERM...09
LONG TERM....15
AVIATION...33
Area Forecast Discussion
National Weather Service Tallahassee FL
936 PM EDT Tue Jun 25 2024
...New UPDATE...
.UPDATE...
Issued at 934 PM EDT Tue Jun 25 2024
No significant changes to the previous forecast appear necessary.
&&
.NEAR TERM...
(Through Wednesday)
Issued at 356 PM EDT Tue Jun 25 2024
Generally summertime pop-up showers and thunderstorms are expected
this afternoon and tomorrow afternoon. Forcing for ascent will be
diurnally driven with the sea breeze being a focal point for
initiation. Similar to today, tomorrow will have the Florida
counties as having the best chance of seeing any activity as higher
dew points and instability reside there. Dew points decrease through
the afternoon tomorrow across SE Alabama and SW Georgia as drier air
aloft mixes down to the surface. The HRRR is suggesting an MCS will
move south across Alabama with some residual outflows colliding with
the sea breeze across SE Alabama and the FL Panhandle. There`s low
confidence that`ll happen, but should it come to fruition, these
areas could see some brief strong storms late tomorrow afternoon.
Expect daytime highs generally in the mid to upper 90s with
overnight lows generally in the mid to upper 70s.
&&
.SHORT TERM...
(Wednesday night through Thursday night)
Issued at 356 PM EDT Tue Jun 25 2024
PoPs will gradually increase through the short term as the mid level
ridge retreats slightly westward with a bit more troughing and
moisture coming into place. Highs are expected to drop back slightly
into the mid 90s for Thursday with the increase in moisture and
slightly uptick in rain chances. However, heat index values will
remain on the high side over 100 areawide. Lows will remain muggy in
the mid 70s.
&&
.LONG TERM...
(Friday through Monday)
Issued at 356 PM EDT Tue Jun 25 2024
Near average rain chances for this time of year are expected through
the long term with 40-50% chances each day. NBM PoPs seem to be
running high lately, so the official forecast decreased them around
10% each day. Upper level ridging may build back into the area
towards the middle and end of the period with highs climbing back
into the upper 90s to around 100 with heat index values in the 105-
110 range, highest across Florida.
&&
.AVIATION...
(00Z TAFS)
Issued at 708 PM EDT Tue Jun 25 2024
VFR conditions are expected through the period. VCTS is expected
at all terminals Tuesday afternoon and evening except for ABY.
&&
.MARINE...
Issued at 356 PM EDT Tue Jun 25 2024
West to southwest winds generally less than 15 knots are expected
through the period. Seas will generally be between 1 to 3 feet, with
the 3 foot waves being favored west of Apalachicola. Long period
swells will continue today before dropping to around 4 to 5 seconds
by Wednesday. Nightly chances of showers and storms will be possible
over the waters with the highest chances east of Apalachicola.
&&
.FIRE WEATHER...
Issued at 356 PM EDT Tue Jun 25 2024
Generally west to southwest transport winds around 10 to 15 mph and
high mixing heights will lead to good to excellent dispersions the
next few afternoons. Dispersions will be high across the Alabama and
Georgia zones tomorrow, then across the Georgia zones and near the
Suwannee Valley on Thursday. Minimum RH values will recover over the
next few days to being generally above 40%.
&&
.HYDROLOGY...
Issued at 356 PM EDT Tue Jun 25 2024
Isolated to scattered afternoon thunderstorms could lead to
localized flooding concerns where slow moving storms could produce
several inches of rainfall over small areas. However, a widespread
heavy rainfall is not expected. Otherwise, there are currently no
river flooding concerns.
&&
.SPOTTER INFORMATION STATEMENT...
Spotter activation is not requested. However, spotters are always
encouraged to safely report significant weather conditions when they
occur by calling the office or tweeting us @NWSTallahassee.
&&
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 77 96 75 93 / 20 60 20 60
Panama City 80 91 77 89 / 20 50 40 60
Dothan 75 97 74 93 / 10 40 30 60
Albany 74 99 74 96 / 0 30 20 60
Valdosta 75 98 75 95 / 30 50 30 60
Cross City 76 93 75 92 / 50 50 30 60
Apalachicola 79 89 78 88 / 10 50 40 60
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...High Rip Current Risk until 6 AM EDT /5 AM CDT/ Wednesday for
FLZ108-112-114-115.
High Rip Current Risk from Wednesday afternoon through Thursday
morning for FLZ112.
GA...None.
AL...None.
GM...None.
&&
$$
UPDATE...DVD
NEAR TERM...Oliver
SHORT TERM...DVD
LONG TERM....DVD
AVIATION...LF
MARINE...DVD
FIRE WEATHER...Oliver
HYDROLOGY...DVD