Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 06/24/24
Area Forecast Discussion
National Weather Service La Crosse WI
1103 PM CDT Sun Jun 23 2024
.KEY MESSAGES...
- Showers and thunderstorms return to the forecast Monday
evening into Monday night, with a conditional risk for severe
thunderstorms. A Slight Risk (level 2 of 5) for severe weather
remains for Monday evening. Should everything come together
and severe storms storms develop, significant (75+ mph) wind
gusts could occur.
- Another brief break for mid-week before additional shower and
storm chances return late in the period. Details to be refined
in the coming days.
&&
.UPDATE...
Issued at 700 PM CDT Sun Jun 23 2024
Continue to monitor incoming guidance concerning the
thunderstorm threat for Monday night. Latest RAP/HRRR capping to
incoming surface-based instability is really really strong
(300-500 J/Kg of CIN) with the elevated mixed layer moving into
the region from the southwest. Using 700 mb temperature as a
proxy to capping strength, by 00Z Tuesday /7 pm Monday/, the 12C
line is well into the area running from KEAU-KDBQ, and only
warming into the evening on strong warm air advection from the
southwest. The cap weakens to the northeast with the gradient
aligning from MSP-EAU-DLL-MSN /I-94/. The latest extended HRRR
run from 23.18Z now forecasts speckles of reflectivity over the
forecast area later Monday, representative of some mid-level
saturation and very limited elevated instability, with the
convective system tracking from nrn MN into the UP/nrnWI. This
makes sense as it is riding around the capping in place further
south, although it may be a bit too far northeast. In any case,
should this strong of a cap build in, the chances really
increase for a system to track northeast of I-94.
&&
.DISCUSSION...
Issued at 205 PM CDT Sun Jun 23 2024
This Afternoon and Evening: Sprinkles and a Stray Thunderstorm
Progged soundings show modest instability this afternoon and
evening in the northern portions of the forecast area. While dry
air above the top of the mixed layer has inhibited vertical
growth thus far in our CWA, plenty of cumulus are seen on
visible satellite and, farther northwest, a couple showers and
thunderstorms have developed west of Hawyard. Have thus added
low end mentions of thunder to the forecast this afternoon and
evening.
Monday Evening and Night: Conditional Severe Risk
After one nice, sedate, temperate day with dewpoints in the
lower 60s for Sunday, warm and muggy conditions return by Monday
afternoon as southwesterly 850mb moisture advection resumes in
earnest. As this occurs, strong EML looks to advection eastward
with 700-500mb lapse rates approaching 8-8.5 C/km. Thus, expect
CAPE values to increase markedly, with progged MLCAPE exceeding
3000 J/kg in our CWA. Stout capping across the forecast area
should keep convection from developing in our area directly but,
farther to the northwest, a combination of a slightly weaker
EML and cooling aloft ahead of a shortwave may allow convection
to develop. Should this occur, progged sfc-6km shear there is
around 55 knots, so expect organized convection to develop, with
the relatively straight hodographs above 1km suggesting
splitting storms and subsequent upscale growth into an MCS would
occur. As 850mb moist fetch only ramps up across the CWA in the
evening, it is plausible that this MCS would be able to dive
southeastward through the forecast area. Given the strong shear
and very high instability, this could result in significant
(75+ mph) wind gusts were it to occur. All the above said, the
strong EML suggests that initiation is not a given and neither
is the ability for any MCS to survive the trek southeast.
For Tuesday, while blended guidance continues to show the
potential for additional convection, am doubtful this occurs as
guidance has generally sped up the passage of the front
associated with the aforementioned shortwave that may kick off
an MCS the previous night. If that MCS does occur, resulting
cold pool would likely force the boundary well south of the CWA.
In either case, while SPC has a Slight Risk (level 2 of 5) in
portions of NE IA and SW WI based on the 00z guidance suite, CSU
ML-based outlooks using the 12z suite show a notable trend away
from our forecast area in line with a faster progression.
Rest of Week: Midweek Break, Another Round Possible
Friday/Saturday
Surface high pressure in the wake of Monday night/early
Tuesday`s front and a reduction in heights aloft should serve to
keep things cooler than normal and precipitation free Wednesday
and Thursday.
Friday and Saturday, next longwave trough looks to advance
eastward just to our north. While precipitation is a good bet, guidance
shows a variety of timings with this feature, so rain mentions
are spread across Thursday night through early Saturday for now.
Additionally, severe thunderstorm risk is uncertain as well as
it remains unclear just how much instability there will be when
best upper forcing arrives.
&&
.AVIATION /06Z TAFS THROUGH 06Z TUESDAY/...
Issued at 1057 PM CDT Sun Jun 23 2024
VFR conditions are forecast for Monday. However, during the
evening hours, thunderstorms could develop over central MN and
move southeast toward the airfields. There is very warm air
above the surface which should favor thunderstorms to form
further north and east - toward KMSP to KDLL and northeast
generally. Wind shear profiles combined with the instability,
should it be released, would form severe thunderstorms with
large hail and mainly a damaging wind threat.
For now, have decided to add VCSH and a VFR BKN cloud deck for
Monday evening until confidence can grow in a given outcome.
&&
.HYDROLOGY...
Issued at 613 AM CDT Sun Jun 23 2024
Heavy rainfall over the previous couple of days has resulted in many
area rivers and streams running high or in flood stage. Flooding
concerns will last well into the week, with the Mississippi
River also continuing to rise. Fortunately, little rainfall is
expected into Monday. However, another round of showers and
thunderstorms will be possible Monday night into Tuesday.
Although some details are uncertain at this time, will need to
monitor for any further potential hydro impacts with these
storms. Please continue to reference the latest flood
statements for additional updates and details.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
IA...None.
&&
$$
UPDATE...Baumgardt
DISCUSSION...Ferguson
AVIATION...Baumgardt
HYDROLOGY...EMS
Area Forecast Discussion...UPDATED
National Weather Service Brownsville TX
530 PM CDT Sun Jun 23 2024
...New AVIATION...
.SHORT TERM...
(Tonight through Monday night)
Issued at 222 PM CDT Sun Jun 23 2024
Key Messages:
- Tropical Disturbance off the NE Mexican Coast moves inland
tonight.
- Rain chances lower as heat builds
-Minor Coastal Flooding and High Risk of Rip Currents through
Monday.
The latest on Invest 93L. A reconnaissance aircraft investigated
the area of disturbed weather earlier today and found a weak
circulation about 40mi SE of La Pesca, Mexico or 170mi South of
Port Isabel. Latest satellite loops verify this exposed center
east of the Mexican coast with the majority of the convection west
of the center over land. Models show the center moving inland by
sunset and that should end any further development. The
disturbance should weaken considerable later tonight and Monday as
it continues to track west along the southern periphery of the
500mb ridge centered over West Texas.
As for our rainfall chances diurnal convection is forecast due to
plenty of residual moisture from the surface to 700mb. With the
upper ridge becoming well established and subsidence increasing,
coverage of convection is likely to decrease. Deterministic and Hi-
res models as well as the National Blend of Models (NBM) are on the
same page here showing 30-40% over land the remainder of today and
again Monday late morning spread west through the afternoon with
some assistance of the sea breeze. Convection should wane this
evening/tonight overland and redevelop over the Gulf waters
overnight as instability increases over the water.
Coastal Rip current risk and the minor coastal flooding look to
persist through Monday as an 8 second moderate swell continue to
be directed towards the lower Texas coast due to a long fetch of
easterly winds. Will maintain the coastal flood advisory and the
rip current statement (Currently expires 7 PM Monday) until we see
more substantial decrease in the swell train.
Temperatures look to inch up into the mid 90s with less rain
coverage and more sun peaking through the clouds. Humidity and heat
indices are likely to be elevated Monday afternoon with max "feel
like" temperatures nearing 110 degrees in several locations. Muggy
overnight lows range 75-80 degrees the next few mornings.
&&
.LONG TERM...
(Tuesday through next Sunday)
Issued at 222 PM CDT Sun Jun 23 2024
The long term forecast for Deep South Texas will feature seasonable
temperatures for late June and fairly limited daily precipitation
chances. The mid/upper level ridge will be centered over West Texas
Tuesday and Wednesday, before gradually shifting toward the Southern
Plains once again heading into the weekend. Meanwhile, low level
southerly flow will maintain elevated humidity across Deep South
Texas, as well as high precipitable water values through the week.
Rain/storm chances will be limited mainly to any showers and
thunderstorms that are able to develop off of the sea breeze each
afternoon on Tuesday and Wednesday, but should be fairly limited.
Deterministic guidance indicates unsettled weather may return
towards the end of the week as a shortwave traverses along the
periphery of the ridge into South Texas. In combination with high
moisture content, this could result in an uptick in precipitation
coverage late this week and into the weekend. There is still some
uncertainty on this potential, and PoPs have been confined to mostly
the 20-50 percent range.
Outside of precipitation chances through the week, the main weather
story in the long term period will be the return of triple-digit
heat indices. Elevated dew points, associated with well established
low level southerly to southeasterly flow, and generally near normal
temperatures will result in heat indices ranging 104 to 111 degrees
degrees each afternoon. The NWS Heat Risk tool indicates a moderate
risk of heat-related illness, which would mainly affect groups
sensitive to heat (children, elderly, chronically ill) and those
spending prolonged periods outdoors without adequate breaks or
hydration. Regardless of the issuance of any heat headlines,
remember to take proper precautions from the heat to prevent any
heat-related illnesses.
&&
.AVIATION...
(00Z TAFS)
Issued at 524 PM CDT Sun Jun 23 2024
VFR conditions will prevail at the aerodromes through the next 24
hours, with generally partly cloudy skies and light winds. A TEMPO
has been added for a portion of Monday based on the HRRR model
guidance, which suggests convection for the late morning into the
early afternoon.
&&
.MARINE...
Issued at 222 PM CDT Sun Jun 23 2024
Tonight through Monday Night...The tropical disturbance currently
located 40mi northeast of La Pesca, Mexico or approximately 170mi
S of Port Isabel, TX is expected to move inland over NE Mexico
later this evening or tonight. No further significant development
is anticipated with this system. Light to moderate east to
southeast wind persist through the period with seas steadily
subsiding Monday. The coastal waters can expect slow improvement
as seas and residual swell trend lower the next 24-36 hours.
Surface high pressure over the Gulf will maintain light east to
southeast winds through Monday night.
Tuesday through Sunday...Generally favorable marine conditions
are expected over the Gulf waters and Laguna Madre as light to
moderate southeast winds and low to moderate seas prevail.
Isolated to widely scattered showers and thunderstorms will be
possible through the week, which may result in higher winds and
seas.
&&
.PRELIMINARY POINT TEMPS/POPS...
BROWNSVILLE 80 93 79 93 / 40 50 10 20
HARLINGEN 76 94 76 95 / 20 40 0 20
MCALLEN 78 95 78 95 / 40 40 0 20
RIO GRANDE CITY 77 94 77 93 / 40 40 10 10
SOUTH PADRE ISLAND 82 87 82 87 / 30 40 10 20
BAYVIEW/PORT ISABEL 79 90 78 91 / 20 40 0 20
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...Coastal Flood Advisory until 7 PM CDT Monday for TXZ351-354-355-
451-454-455.
High Rip Current Risk through Monday evening for TXZ451-454-455.
GM...None.
&&
$$
Area Forecast Discussion
National Weather Service Quad Cities IA IL
929 PM CDT Sun Jun 23 2024
.KEY MESSAGES...
- Heat to temporarily return early this week, with high
confidence in 90s for highs south and west of the Quad Cities
on Monday, and then a higher ceiling (mid 90s) and with heat
index readings (around 100) on Tuesday, but uncertainty with
any morning thunderstorm residual effects
- Potential (30-50%) for semi-organized thunderstorms late Monday
night into Tuesday morning mainly north of Highway 30, with
higher confidence in thunderstorms late Tuesday afternoon into
Tuesday night especially along and south of I-80 that would pose
at least a scattered heavy rain and severe threat (risk level 2
out of 5).
- Rivers expected to rise through midweek from upstream rainfall
last week and possibility of heavy rainfall on Tuesday and
Tuesday night (25% chance of exceeding one inch).
&&
.SHORT TERM /THROUGH MONDAY/...
Issued at 255 PM CDT Sun Jun 23 2024
High pressure of 1013 mb will scoot over the area tonight. Warm
air advection (WAA) aloft will already be resuming overnight
and will likely result in some clouds developing late into
early Monday morning. Cannot rule out patchy fog (~10 percent
chance) in northern locations late tonight, even though not
climatologically favored, just due to wet ground and forecast
lows a few degrees below current mid 60s dew points.
Gauging by HREF and RAP solutions, any clouds early Monday
morning should depart northeast of the area as the low-level
thermal ridge builds back in. Forecast 850 mb temperatures by
mid-afternoon are 21-22C, and with full sunshine and southerly
winds, would not be surprised if a few locations in southeast
Iowa and northeast Missouri tag 94-95 degrees for a high. Dew
points are not forecast to have climbed much from the mid 60s
yet, so heat index readings are forecast in the upper 90s.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
Issued at 255 PM CDT Sun Jun 23 2024
The Plains upper level ridge will start to be dampened some
again on Tuesday as a strong, slightly positively-tilted trough
tracks across southern Canada into the eastern Great Lakes
region. The quasi-zonal flow atop the ridge will be unsettled,
with a lead impulse Monday night over the Upper Mississippi
Valley. The primary synoptic front will be dragged southeastward
over the area on Tuesday afternoon and evening by the deep (sub
990 mb) low north of the Great Lakes. This is the most
favorable synoptic signal for thunderstorm coverage and
potential hazards.
For Monday night into Tuesday morning, confidence is highest in
warmth, with southerly winds of 10-15 mph not allowing much
temperature drop at all. Lows look to solidly be in the 70s
(likely to fall just short of record warm mins for the calendar
day Tuesday, June 25). Along the still strengthening front in
Minnesota into western Wisconsin on Monday evening, convection
should develop over a several hour period. Orientation of shear
vectors to the front is oblique to perpendicular, so it may
take a while to grow upstream into an organized convective
complex. However, most CAMs support an organizing morphology
with 50+ kt of mid-level flow during peak low-level jet time.
Thickness diffluence and Corfidi vectors support a southeast
propagation of cold pool-driven, organized convection, and could
mean thunderstorms moving into the northern to northeastern CWA
after midnight. Wind would be the primary threat if this
evolves, along with possibly a localized flood risk with any
backbuilding activity on the far southwest edge of such a
convective feature that would be over our already wet north CWA.
Influences of convection, even if its just a northerly wind
shift with rain-cooled outflow, will have effects on convective
evolution for Tuesday afternoon and evening. This naturally
lowers the confidence on convective details. Despite that, given
the warmth and moisture resulting in substantial instability
combined with the synoptic scale cold front moving in,
thunderstorms are likely (>60%) to redevelop along and south of
the general I-80 zone and evolve east-southeast. This may
include our entire CWA too, but again depends on details from
Monday night. The less influence on late Monday night/Tuesday
morning, the more of our area that should see Tuesday afternoon
and evening thunderstorms.
The heat on Tuesday will be part of the fuel for any
thunderstorms on Tuesday. Using NBM membership, there is 40-60%
chance of exceeding 95 degrees south of I-80, and with 850 mb
temperatures of 22-25C, that certainly is in play using
climatology for 95+ degree days in our region. Also acting as
fuel are precipitable waters around two inches (upper 5th
percentile), setting the stage for precipitation-loaded
downdrafts and potential flash flooding issues. Shear vector
orientation with respect to the front or any outflow-associated
boundary is forecast to be more oblique, and can see a clustered
convective evolution possible. As noted in previous AFD, the
forecast Corfidi vector orientation indicates training, slow-
moving storm potentail as well, but again confidence is on the
lower end on where that may be in our CWA late in the day and
throughout Tuesday evening. Currently forecast potentail for
rainfall to exceed one inch is 15-25 percent from west to east
across the CWA.
Beyond, the temperatures will ease back to normal Wednesday and
Thursday, before the GFS and ECMWF and a large membership of
their ensembles provide a return to a more active pattern. There
is a signal for a deeper synoptic scale system closer to our
latitude in the Midwest late in the week, which would mean
severe and heavy rain potential and the CSU machine-learning
probabilities already hint at these too.
&&
.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 630 PM CDT Sun Jun 23 2024
VFR conditions are expected through the TAF period with periodic
SCT-BKN clouds 5-8kft agl. Northwest winds around 10 kt will
become light and variable after sunset into early Monday
morning, with the transitory passage of weak surface high
pressure. By Monday afternoon south to southeast winds will
increase to over 10 kt, with occasional gusts around 20 kt at
CID and possibly DBQ.
&&
.HYDROLOGY...
Issued at 929 PM CDT Sun Jun 23 2024
No significant changes for the Cedar River basin this evening
with the new forecasts. The rise on the Cedar River at Cedar
Rapids has been slowed some and still may reach 14 ft or
Moderate flood stage early Friday.
For the Mississippi, flood watches have been converted to flood
warnings for Dubuque Lock and Dam, Camanche, and Rock Island
Lock and Dam sites this evening. Additional warnings can be
expected in the coming days.
.Previous Discussion.
The Mississippi River is expected to reach flood stage at
multiple locations, including the Rock Island gage, by the
middle of this week. Long term we expect the Mississippi to
reach Moderate and/or Major flood stages the week of the Fourth
of July, with the crest at the Rock Island gage possibly
reaching just over 18 feet early on the Fourth of July.
However, a larger margin of error should be taken into
consideration when forecasting precipitation amounts and
locations in the 7-10 day timescale. Watches are currently out
for most of the Mississippi River and warnings will follow in
the next few as a clearer picture is drawn on what
precipitation and routed water we have coming downstream. In the
latest forecast package, we have opted to upgrade Gladstone and
Burlington to a River Flood Warning, aided by the recent
rainfall north of the area.
The Rock River is also expected to reach flood stage in Joslin,
with an increase noted into Action Stage at Moline. A River Flood
Warning has been issued for Joslin in this latest forecast
package, which is forecast to hit flood stage tomorrow
afternoon. We will continue to see additional rainfall through
this coming week, which may lead to further fluctuations in the
river levels. If heavy rainfall is seen, then increases can be
expected.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...None.
IL...None.
MO...None.
&&
$$
SHORT TERM...Friedlein
LONG TERM...Friedlein
AVIATION...McClure
HYDROLOGY...Gross/Gunkel/Wilson
Area Forecast Discussion
National Weather Service Grand Forks ND
1000 PM CDT Sun Jun 23 2024
.KEY MESSAGES...
- Showers and thunderstorms will move into eastern North Dakota,
especially northeast parts, after midnight tonight. Isolated
severe storms are possible.
- Monday will see additional severe storm chances for all areas.
- The next storm threat arrives in the Thursday to Friday time
frame.
&&
.UPDATE...
Issued at 1000 PM CDT Sun Jun 23 2024
Convection is now starting to form across northeastern Montana
and northwest North Dakota this evening; however, most CAMs are
not picking up on this development. Guidance is temporally
displaced by at least a few hours in most cases, with the HRRR
and NAMNest weakening convection as it approaches eastern North
Dakota. Will continue to monitor the environmental conditions
ahead of these storms as they approach the area. At this time,
current guidance brings the first storms into the Devils Lake
area by around 09Z, then into the Red River Valley by around
12Z.
UPDATE
Issued at 655 PM CDT Sun Jun 23 2024
The forecast remains on track this evening with temperatures in
the low 70s along the International Border and low 80s in the
southern Red River Valley. Isolated cumulus continues to
diminish in coverage across northwest Minnesota with otherwise
clear skies across the region. Watching for development of
convection in western North Dakota in the coming hours in order
to determine timing of any potential morning convection across
eastern North Dakota.
&&
.DISCUSSION...
Issued at 233 PM CDT Sun Jun 23 2024
...Synopsis...
The first 700mb shortwave over the Minnesota arrowhead continues
to push to the east. Haven`t seen any precipitation in this FA
from the wave, but there has been fairly extensive cloud cover.
Brief 500mb ridging follows this wave, although overall it looks
much flatter and a little faster than it did several days ago.
There may be some pieces of shortwave energy (and somewhat of a
low level jet) that eject eastward behind this ridge after
midnight and into Monday morning, which may bring scattered
thunderstorms to portions of the Devils Lake region and eastern
North Dakota. There may or may not be a break as this activity
should weaken over this FA by mid to late morning, before
additional storms fire up during the afternoon. The net result
of the flatter/faster ridging is that the warmest 700mb
temperatures on Monday are squashed a little further south and
east. Even so, by 18z Monday to 00Z Tuesday, 700mb temperatures
look to range from +9C along the Canadian border to +15C along
the Dakotas border. Beyond this, the flow turns more northwest,
with the next substantial wave sometime in the Thursday to
Friday time period.
...After midnight tonight...
The various CAM solutions seem to agree on scattered storms
developing over southern Saskatchewan or western North Dakota
after midnight tonight, with them moving into the Devils Lake
region or portions of eastern North Dakota toward sunrise
Monday morning. The Day 1 SPC Convective Outlook highlights a
slight risk (level 2 of 5) for far northwest North Dakota,
tapering to a marginal risk (level 1 of 5) for the Devils Lake
region. The HREF shows the stronger UH tracks during this period
extending from northwest North Dakota toward the western
fringes of this FA and weakening toward morning. So will keep
the idea of weakening storms and a good amount of cloud cover
moving into at least areas north of the Interstate 94 corridor
in North Dakota and the highway 10 corridor in Minnesota
tonight.
...Monday...
There is not a lot of confidence in what may happen on Monday,
but to start with, what happens late tonight and lingers into
Monday morning will have a big effect. Looking at the various
CAMs, etc., feel there could be several different potential
solutions. One, the convection moving into the Devils Lake
region and portions of eastern North Dakota weakens and there is
a break until more convection develops in the afternoon. Two,
there is no break, and convection continues throughout the
entire day across the entire FA (several CAMs show long duration
UH track across the central and northern FA even during the
late morning through the afternoon. Third, although most CAMs
show a better chance for afternoon convection in the eastern
FA, a few show some development back along the cold front, which
may lag back in eastern North Dakota by 00z Tuesday (which
could be part of the reason the slight risk area was expanded
westward today). Fourth, the development which occurs back along
the cold front quickly becomes severe and turns into a bowing
MCS, producing damaging wind gusts as it progresses across west
central Minnesota along the highway 10 corridor in late
afternoon and early evening hours. Five, much of the capping
holds, and only minimal convection occurs. Overall, there is a
lot of uncertainty.
...Thursday to Friday...
The general 500mb flow pattern should turn more to northwest
flow aloft, with the next decent wave showing up somewhere in
the Thursday to Friday time frame. Overall there is a lot of
uncertainty on the timing and strength of the wave, so don`t
want to put a lot of time into trying to determine what may
occur. Stay tuned.
&&
.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 625 PM CDT Sun Jun 23 2024
VFR conditions prevail this evening and into the early overnight
period at all TAF sites. Showers and thunderstorms are expected
to move into eastern North Dakota later tonight, impacting KDVL
first as early as 09Z, then moving off to the east through the
remainder of the morning hours. Winds are expected to become
southerly gradually through the overnight hours, with wind
speeds in the 10 to 15 knot range by Monday morning.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...None.
MN...None.
&&
$$
UPDATE...Lynch
DISCUSSION...Godon
AVIATION...Lynch
Area Forecast Discussion
National Weather Service Grand Rapids MI
1024 PM EDT Sun Jun 23 2024
.KEY MESSAGES...
- Two Rounds of Strong to Severe Storms Possible Tuesday
- Dry Mid Week With Rain Returning Friday
&&
.UPDATE...
Issued at 1024 PM EDT Sun Jun 23 2024
Have updated the forecast to include scattered showers along with
isolated thunderstorms up in the northwest CWA towards Ludington.
A strong upper shortwave trough is diving southeast through the
Northern Great Lakes this evening. Cold mid levels associated with
the trough and surface moisture via Lake Michigan are aiding in
instability. Surface dew points around Lake Michigan remain in the
60s. HRRR soundings from out over the lake at 02Z show very small
pockets of instability of 500-1000 j/kg. This is clearly enough
instability to produce both showers and thunderstorms. At this
point we have confined chances for showers and storms to the
northwest forecast area to the north and west of GRR. If the
activity holds together longer we will update the forecast as
necessary.
Otherwise expecting a clear / partly cloudy night with cool
temperatures in the 50s.
&&
.DISCUSSION...
Issued at 257 PM EDT Sun Jun 23 2024
For tonight and Monday, no changes of note. Some model guidance
brings some brief sprinkles to our northwest forecast area and
adjacent waters, but this is low probability and non-impactful
even if it occurs. Otherwise, we are seeing a gradual erosion in
clouds and this should be hastened this evening by nocturnal
stabilization of the boundary layer.
- Two Rounds of Strong to Severe Storms Possible Tuesday
An active long term period is expected across West Michigan. The
first timeframe of concern will be early Tuesday morning as a
typical "ridge rider" MCS pattern sets up. Thunderstorms across
Minnesota and Wisconsin will grow upscale into an MCS. Consensus
among a majority of the 12z CAMS is this arrives still intact with
500+ J/kg of MUCAPE advecting in ahead of it. Some uncertainty
exists in two key areas that will determine whether damaging winds
affect the CWA. First is the extent of low-level stability. Model
soundings show a notable low-level stable layer which may limit to
what extent winds can mix to the surface. Second is uncertainty as
to how much instability advects in ahead of this feature
determining how quickly the MCS dies. The best chance of any wind
impacts if they occur will be along and northwest of a South Haven
to Clare line. Given the progressive nature of the MCS flooding is
not expected with this round.
A second round of severe storms is possible Tuesday afternoon.
However, certainty remains lower as afternoon convective evolution
will depend on evolution of the morning MCS. Model consensus is that
atmospheric recovery does occur behind the MCS with LREF 50th
percentile CAPE values climbing to 1500 J/kg Tuesday evening. In
addition, the morning MCS activity brings the potential of leaving a
remnant outflow boundary which could serve as a convective trigger.
By late Tuesday afternoon into the evening, a cold frontal boundary
moves through the CWA bringing the potential for strong to severe
storms mainly near and south of I96. The main question with this
round is shear. While a low-level jet will be in place, the mid-
level jet will be displaced to the Northwest limiting deep-layer
shear. However, forecast soundings suggest 25-35 knots of effective
shear which would be enough to support a severe weather risk
combined with the ample CAPE. This will need to be monitored over
the next 48 hours as mesoscale trends become more apparent. The
other concern is excessive rainfall. Mean cloud-layer winds look to
be front-parallel which brings a chance of training storms and
locally heavy rain as a result.
- Dry Mid Week With Rain Returning Friday
Wednesday into Thursday will feature dry weather across West
michigan as approaching surface and mid-level ridging cause dry
conditions and at partly cloudy or better skies across West
Michigan. By Friday into Saturday there is a decent signal across
guidance for chances of showers and storms. Chances begin Friday
associated with warm air advection and the lifting of a warm frontal
boundary across the CWA. A cold frontal boundary causes shower and
thunderstorm chances to continue into Saturday as a cold front
passes through.
&&
.AVIATION /00Z TAFS THROUGH 00Z MONDAY/...
Issued at 720 PM EDT Sun Jun 23 2024
This set of forecasts are expected to feature low impacts for
aviation users over the next 24 hours and beyond. Lower clouds
from earlier have scattered out significantly at all sites but
KJXN as of 23z. The clouds will continue to clear out through the
evening, and should stay mostly clear overnight. Winds remain a
little gusty as of 23z, but the winds should come down to light
and variable overnight.
Clear skies and light winds usually point to potential fog. All of
the guidance we have reviewed indicates that enough dry air will
come in to keep fog from forming. We will continue to monitor the
potential.
Winds will stay light and somewhat variable on Monday with high
pressure nearby. A few cumulus clouds will be possible, but will
not be enough to necessitate a change group for it. VFR conditions
will rule.
&&
.MARINE...
Issued at 404 PM EDT Sun Jun 23 2024
Based on most recent trends and plenty of beach traffic per
webcams, we decided to extend the Small Craft Advisory and Beach
Hazards Statement from Grand Haven southward until 8 PM EDT.
Previous discussion follows...
We have seen a recent localized uptick in winds and waves at the
Holland buoy and a similar wind bump at the Muskegon Coastal
Marine station. This matches a small pocket of elevated winds
advertised by the 17Z HRRR. This particular model run shows this
pocket peeling quickly southward along the lakeshore as it becomes
more diffuse, so we are therefore still comfortable with
maintaining a 5 PM expiration for our Small Craft Advisory and
accompanying Beach Hazards Statement.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...None.
MARINE...None.
&&
$$
UPDATE...Duke
DISCUSSION...TJT/Thomas
AVIATION...NJJ
MARINE...TJT
Area Forecast Discussion
National Weather Service Greenville-Spartanburg SC
1002 PM EDT Sun Jun 23 2024
.SYNOPSIS...
A cold front will cross the area tonight and bring a chance of
showers with isolated thunderstorms. Drier conditions return through
Wednesday, before another active cold front moves in from the
northwest Wednesday night into Thursday.
&&
.NEAR TERM /THROUGH MONDAY/...
As of 957 PM Sunday: No major changes to the forecast tonight.
Radar is clear for the moment, but upstream convection in the
Tennessee Valley is just about knocking on our door. sbCAPE is
looking increasingly anemic, especially over the western zones,
and some CIN is beginning to develop over the NC mountains. Still,
we`ll probably see some showers and embedded storms make it into
the high terrain, and a band of 800-900 J/kg DCAPE will permit, once
again, a low-end risk of some gusty winds if cells get tall enough.
Latest hi-res model trends are back to breaking up this line as it
exits the mountains, so the window for any active weather should
be fairly narrow.
Otherwise...a few of the showers might survive east of the mtns
into the pre-dawn hours on Monday, especially over the NC foothills
and NW Piedmont, but altogether no big deal and most places will
stay dry. Low temps will be mild as the weak sfc reflection of
this short wave will not cross the region until the hours around
daybreak. In reality, this isn`t so much a cold front as it is
more of a dry front, which is typical for this area at this time
of year. Behind the boundary, a sfc high will build in thru Monday
afternoon from the NW on the strength of an upstream ridge. The
upshot is that temps Monday afternoon might ultimately be similar
to Sunday afternoon, but the RH should be noticeably less (and less
than we expected a few days ago), such that apparent temps should
stay well below the Heat Index criteria. Precip chances will also
be limited to a slight chance over the eastern-most zones in the
middle part of the day before the boundary moves off toward the
Coastal Plain in the afternoon.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
As of 1230 PM Sunday...Upper heights will begin to rise early Tue
which will support a Canadian sfc high to the north. This high will
dominate the weather into Wed as it becomes reinforced and ridges
down the east coast. Relatively dry and cool air will mix in, but
still expect deep subs to allow for temps in the l90s east of the
mtns and u80s across the mtn valleys. Soundings show mixing into the
drier air aloft which will help keep sfc dwpts in the u50s to l60s
and HI values below adv criteria. The atmos becomes more dynamic
early Wed as a pos tilted h5 s/w pushes in from the west. This wave
will likely produce sct showers and a few general to strong tstms
across the NC mtns with isol activity east thru the day. Rainfall
amts will be modest and wont make much of a dent in the below normal
precip amounts received this month. Surface dewps will bump up in
this environ ahead of the front and along with temps reaching the
mid to upper 90s east of the mtns, heat index values could rise into
advisory levels across the Lakelands. Overnight temps will remain
rather warm with mins held abt 5-7 degrees abv normal.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
As of 205 PM Sunday...An upper trof axis continues to cross the area
Wed night which will likely maintain chance thunder across the NC
mtns and isolated storms east. With high pressure pushing a llvl
convg zone into the area during the afternoon, expect another round
of tstms across the NC mtns. Meanwhile, heights will rise as a
subTrop ridge builds in from the west. This neg forcing will help
keep tstm strength in the general category Thu afternoon and again
Fri afternoon when the llvl flow brings in an upslope e/ly se/ly
flow. The building ridge dominates the pattern into the weekend and
makes for a summertime pattern with PoPs a little below climo and
temps remaining above normal. Expect highs in the m90s each
afternoon and lows likely held a couple cats abv normal. Heat
indices look to remain below adv level Thu and Fri, yet may reach
criteria Sat as dewpts surge ahead of a sfc front approaching from
the northwest Sat night.
&&
.AVIATION /02Z MONDAY THROUGH FRIDAY/...
At KCLT and elsewhere: Cu field is diminishing at this point
with the sun on its way down. Isolated showers over the I-40
corridor are possible over the next 1-2 hours as a weak frontal
circulation pushes into the area...but coverage will be sparse and
shouldn`t impact any of the TAF sites. Another, better-defined
band of showers is expected to arrive in the NC mountains a little
before midnight, and slip across the terminal forecast area through
daybreak. Some embedded thunder is possible, particularly for the
NC zones; coverage over the Upstate terminals will be too paltry
for a mention in the TAFs. Admittedly, the 21z HRRR has come in
more aggressive than past runs, with a better-defined band of
showers and storms affecting all the TAF sites...but not ready
to make a sweeping change to the forecast based only on this.
Anyway, winds will come around to NW after daybreak, leading into
another day of shallow VFR cumulus. Conditions behind the front
should be suppressed enough to inhibit any shower chances on Monday.
Outlook: Drying trend now expected to continue into Tuesday,
with little to no diurnal convection. Summertime humidity will
returns by midweek, with SHRA/TSRA chances also returning.
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...None.
NC...None.
SC...None.
&&
$$
SYNOPSIS...SBK
NEAR TERM...MPR/PM
SHORT TERM...AR/SBK
LONG TERM...SBK
AVIATION...MPR
Area Forecast Discussion
National Weather Service Newport/Morehead City NC
1009 PM EDT Sun Jun 23 2024
.SYNOPSIS...
High pressure remains offshore through tonight. A front will
move through late Monday, with another front impacting the
region Thursday.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
As of 1010 PM Sun...Main cold front continues to gradually push
across the OH river valley tonight while a pre-frontal trough
lingers extends from central VA into the Piedmont of NC. Both
are triggering isolated to scattered thunderstorm activity, but
over eastern NC conditions are dry with the only precipitation
falling offshore.
As the front approaches overnight there will be increasing
upper level support for the development of showers and
thunderstorms across the coastal waters combined with weak
remnant low pressure lifting along the Carolina coast. Most of
the precip will likely remain offshore, though precip could
skirt the immediate coast (best chances from Cape Lookout to
Cape Hatteras). The HRRR continues to advertise an MCS
development well to our south, which would effectively act as a
moisture robber and deny any onshore precipitation chances. Breezy
conditions will continue tonight ahead of an approaching cold
front, as warm and muggy conditions persist. Lows only falling
into the upper 70s to around 80 deg.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
As of 255 PM Sun...Early Monday morning, a weak area of low
pressure (the remnants of the SW Atlantic tropical wave) may be
skirting the Crystal Coast and southern OBX with showers and
thunderstorms. After this wave moves away, a potent shortwave
crossing the NE US will push a cold front southeast across ENC.
This front will be favorably timed with peak heating and the
development of the afternoon seabreeze, setting up a period of
moderate low-level forcing. Southerly flow ahead of the front
will support dewpoints in the 70s. Heating of the moist boundary
layer should support moderate instability (MLCAPE of 1500-2500
j/kg). Shear will be on the marginal side (20-30kt), but still
more than sufficient for organized convection. Scattered to
numerous thunderstorms expected to develop during the afternoon
and evening, posing a risk of damaging winds and large hail.
Clustering of storms plus 2"+ PWATs will also favor a risk of
very heavy rain and minor flooding. It`s been very dry of late,
though, so the flash flood threat appears low. Best chances look
to be areas along and east of Hwy 17.
Combination of temps in the 90s inland and dewpoints in the 70s
may support a risk for dangerous heat across the area. However,
right now it looks marginal and with increasing cloud cover and
precip chances will hold off on potential heat advisory at this
time and let the later shifts re-evaluate.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
As of 230 AM Sunday...
- Increased heat risk continues, especially mid to late-week
Synoptic Summary: Upper level troughing will dominate the Eastern
U.S. through mid to late-week, then upper level ridging begins to
expand east across the Southern U.S. by next weekend. At the
surface, a couple of cold fronts are forecast to move through
the Carolinas, one on Monday evening, and the other on Thursday.
Tuesday-Wednesday: Guidance continue to suggest Monday`s front will
get enough of a push to get all the way through ENC, setting up a
less humid, and more stable, post-frontal airmass on Tuesday. Fronts
tend to get hung up this time of year, and the front should quickly
return north as a warm front Tuesday night. This will allow humidity
to return by Wednesday. Outside of the seabreeze, the convective
coverage looks to be low on Wednesday.
Thursday-Sunday: Continued southerly flow should once again support
higher dewpoints and humidity overlapped with above normal
temperatures and an increased risk of heat impacts. This will
especially be the case by the weekend with ridging overhead and a
lower risk of thunderstorms/clouds.
On Thursday, another decent cold front is forecast to move through
the area, and guidance continue to show a solid signal for another
round of scattered to numerous thunderstorms, some possibly on the
strong side. Outside of Thursday, it appears the convective coverage
will be closer to climo, and mainly seabreeze-driven.
&&
.AVIATION /02Z MONDAY THROUGH FRIDAY/...
SHORT TERM /through 00z Tue/...
As of 755 PM Sun...VFR conditions remain across all areas this
evening. Gusty, pre-frontal southwesterly winds will ease
overnight with loss of heating and mixing, but sustained winds
of around 10 kt will abate any fog threat despite extremely
saturated low levels. However, at least a period of low-level
stratus is favored tonight, especially with an influx of
moisture associated with a weak surface low expected to pass
close to the Crystal Coast tonight. Latest LAMP guidance
suggests any MVFR with these cigs would be more temporary in
nature, and trended TAFs in this direction with the most
pessimistic forecasts for EWN and OAJ. Primary risk window is
from 06-13z.
For Monday, scattered showers and thunderstorms are expected to
develop ahead of an approaching front putting all terminals at
risk especially after 18z. A few stronger thunderstorms, capable
of small hail, gusts to 40+ kt, and torrential rainfall briefly
but severely limiting visibility, are possible.
LONG TERM /Monday night through Friday/...
As of 230 AM Sunday...Predominantly VFR conditions are expected
Tuesday and Wednesday, followed by another increased risk of
TSRA by Thursday.
&&
.MARINE...
SHORT TERM /through Monday/...
As of 255 PM Sun...Latest obs show SW winds 15-25 kt with seas
2-4 ft. Conditions will continue to deteriorate ahead of an
approaching cold front tonight. SSW winds will peak at 15-25 kt
with gusts 25-30 kt tonight into Monday morning. The presence of
a strengthening low level jet overnight may lead to a brief few
hours of Gale Force winds/wind gusts, especially in and around
any scattered showers. SCAs remain in effect for the coastal
waters, sounds and rivers and will continue into Mon morning and
evening. Seas will peak at 5-7 ft overnight. SW winds 15-25 kt
will continue Mon with 4-6 ft seas. A cold front will move
through the waters late Monday and Monday evening and will
feature an increased risk of thunderstorms. Some storms may be
strong to severe Monday afternoon and evening.
LONG TERM /Monday night through Friday/...
As of 230 AM Sunday...
- Elevated winds and seas return mid-week
A post-frontal regime will briefly setup on Tuesday with
easterly winds of 5-15kt and lower seas. Southerly flow then
quickly returns by Wednesday and Thursday, with building seas.
&&
.FIRE WEATHER...
As of 255 PM Sun...
- Elevated fire concerns possible through this evening
Southerly winds will gust 25-30 mph through this evening. With
moisture increasing, RH values will remain elevated this
afternoon, bottoming out only in the 40 to 50% range. However,
given how dry it has been in the last few weeks, the breezy
conditions in the presence of drier fine fuels is noteworthy,
especially for any fire that manages to develop, or any ongoing
fires. Wetting rainfall is still possible on Monday, especially
along and east of Hwy 17, and again Thursday.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...Beach Hazards Statement from 8 AM EDT Monday through Monday
evening for NCZ195-196-204-205.
MARINE...Small Craft Advisory until 8 AM EDT Monday for AMZ131-136-137-
230.
Small Craft Advisory until 2 PM EDT Monday for AMZ135.
Small Craft Advisory until 11 AM EDT Monday for AMZ150-231.
Small Craft Advisory until 8 PM EDT Monday for AMZ152-154.
Small Craft Advisory until midnight EDT Monday night for
AMZ156-158.
&&
$$
SYNOPSIS...MHX
NEAR TERM...CQD/MS
SHORT TERM...CQD
LONG TERM...RM
AVIATION...RM/MS
MARINE...RM/CQD
FIRE WEATHER...MHX
Area Forecast Discussion
National Weather Service Marquette MI
624 PM EDT Sun Jun 23 2024
.KEY MESSAGES...
- Showers and thunderstorms possible this afternoon and evening.
Severe weather is not expected.
- A slight risk (~15%) of damaging wind and hail in the far west
associated with thunderstorms Monday night into Tuesday
morning.
- Tuesday will be the warmest day of the week with highs in the
mid 70s to mid 80s.
- Next round of precipitation expected Thursday night into the
weekend.
&&
.SHORT TERM /THROUGH TONIGHT/...
Issued at 104 PM EDT Sun Jun 23 2024
Clear skies with pockets of mostly cloudy skies have been present
over Upper Michigan today. This has yielded a mix of temperatures,
but overall most areas have climbed into the mid-60s, with a few low
70s here and there. DLH radar returns this morning showed scattered
showers across the northern fringes of the Arrowhead and some light
rain or sprinkles over western Lake Superior. These are associated
with a closed mid-level low and preceding shortwave moving through
western Ontario/northern Minnesota. Some of these have started
showing up in Upper Michigan, but its uncertain if anything is
reaching the ground at this point.
As we progress through the remainder of the afternoon/evening, the
wave aloft opens up as it moves through Upper Michigan. Some very
modest instability may support additional showers and some
thunderstorms this afternoon. Any convective development should
progress southeast and weaken into the late afternoon and evening
hours. High pressure builds in tonight, supporting a mostly clear
night with lows dipping into the high 40s to mid 50s, warmest lake-
side. The combination of cooler conditions, recent rainfall, and a
low level inversion may support fog development across portions of
western Upper Michigan tonight.
&&
.LONG TERM /MONDAY THROUGH SUNDAY/...
Issued at 433 PM EDT Sun Jun 23 2024
Starting Monday, Upper MI will be underneath mid level ridging with
a trough over New England and another more broad trough over the
Canadian Prairie Provinces. With the northern end of a 1015 mb high
pressure ridge shifting southeast through the Great Lakes, we stay
quiet and dry. Meanwhile, the western trough progresses east toward
Saskatchewan/Manitoba throughout the day and its associated sfc low
deepens to around 990mb just north of Lake Winnipeg. This set up
increases southerly flow, increasing warm air and moisture
advection; PWATs increase to around 1.7" by Tuesday evening. Some
lake breezes are possible in the afternoon, but may struggle against
the southerly flow. Otherwise no noteworthy weather is expected.
Highs are expected in the 70s to low 80s.
Monday night through Tuesday the mid level trough over Manitoba
moves east, becoming centered just east of James Bay. The associated
sfc low moves east with it, moving through far northern Ontario,
reaching James Bay Tuesday afternoon, and then continuing east into
Quebec Tuesday evening. This sfc low well to the north drapes a cold
front south into the midwest that moves into the far western UP
around 6Z Tuesday, supporting showers and storms aided by isentropic
ascent. The significant uncertainty yet with how the convection
along the front plays out is well represented by the wide range of
solutions among the CAMs. Model soundings show a decent cap and the
6/23 12Z HREF mean CIN is ~100 J/kg Monday evening across much of
the western UP. Also, stronger large-scale ascent with the tough
will remain north of the international border. That said, a small
region of MUCAPE (HREF mean of 1000-2000 J/kg) builds up over
Gogebic/Ontonagon/S Houghton/Iron counties Monday night; values as
high as 2500-3000 J/kg are not out of the question. Mid level lapse
rates will increase to ~7 C/km with bulk shear between 35-40 kts. If
we are able to break the cap with the frontal boundary passing
through as well as a strengthening LLJ, the environment will be
supportive of strong to severe storms with damaging hail and winds
being the main threats.
This event will depend on how upstream convection earlier in the day
plays out. Some solutions including the 12z runs of the NAM
Nest/ARW/FV3 depict a more pronounced MCS developing over northern
MN, progressing through the region. The MCS tracks are spread as
well with some only clipping the WI/MI border while the FV3 tracks
right across our CWA. The HRRR and RAP are not as organized or
strong. Given the potential environment, the SPC slight risk (15%)
for the far west seems appropriate. This event will continue warrant
monitoring as uncertainty remains high. Showers and storms continue
east across the UP through the rest of the day Tuesday as the front
continues out. As the trough presses south in the later part of the
day, PVA supports additional shower and storm chances, mainly over
the east half of the UP. Otherwise, Tuesday is expected to be the
warmest day of the week with highs in the mid 70s to mid 80s. Mixing
behind the front late morning/early afternoon will help alleviate any
early muggy conditions in the morning.
A dry period then is expected Wednesday into Thursday night as high
pressure descends southeast through the Great Lakes from the
Canadian Prairie Provinces. Confidence is growing in the weekend
forecast for a trough over the Pacific NW to make landfall Wednesday
night, then continue east along the U.S./Canada border, and reaching
the Upper Great Lakes by Saturday. This will support cyclogenesis in
the northern Rockies Thursday night/Friday with the low ejecting
east-northeast to just north of Lake Superior for Friday
night/Saturday. Drier weather looks to return the rest of the
weekend as high pressure returns.
&&
.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 624 PM EDT Sun Jun 23 2024
VFR conditions will continue through the period.
&&
.MARINE...
Issued at 433 PM EDT Sun Jun 23 2024
West to northwest winds will diminish through this evening, then
remain below 20 kts through Monday as high pressure ridging passes
over Lake Superior. South winds increase to around 20 kts Monday
night ahead of a passing cold front. Southwest winds behind the
front are expected around 20-25 kts, though a few gusts may be in
the 25-30 kt range between Isle Royale and the Keweenaw Peninsula
Tuesday afternoon. Winds taper off Tuesday night into Wednesday as
they veer north, remaining below 20 kts through the late part of the
week.
Strong to severe storms are possible in the west Monday night into
Tuesday with the passing cold front. Waves will be strongest between
Isle Royale and the Keweenaw Peninsula Tuesday afternoon and evening
(4-6 feet).
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
SHORT TERM...JTP
LONG TERM...Jablonski
AVIATION...07
MARINE...Jablonski
Area Forecast Discussion
National Weather Service Nashville TN
853 PM CDT Sun Jun 23 2024
...New UPDATE...
.UPDATE...
Issued at 839 PM CDT Sun Jun 23 2024
The cold front has cleared Nashville and is now located along the
Plateau where most of our current storm activity is. Mid- level
lapse rates never got too steep today, so most storms stayed
pretty shallow. That continues to be the case with the storms
currently on radar. Looking at the latest meso data around the
area, instability continues to fall behind the cold front. A few
smaller thunderstorms have popped up across the west that are
using the last bit of instability the environment has to offer. Do
not expect those to be of much consequence outside of producing
heavy rain and lightning. As a more stable airmass builds in over
the next few hours, clouds will start to clear and temperatures
are expected to drop into the low 70s overnight. With the recent
rain and clearing skies tonight, patchy dense fog appears likely
overnight as we approach daybreak, especially for those along the
Plateau. High pressure will return to the area tomorrow, meaning
another hot day is in store with highs near 90. Thankfully, dew
point temperatures aren`t expected to be as high as they have
been, thus the "feel like" temperature will be very close to the
actual temperature tomorrow - 90. Hot and dry weather will stick
around with us through Tuesday.
&&
.SHORT TERM...
(Rest of today through Sunday Night)
Issued at 1120 AM CDT Sun Jun 23 2024
Radar late this morning shows a weakening line of light rain
showers moving southeastward across northern parts of the
midstate. This activity should continue to weaken over the next
couple of hours as it moves further southeast. However,
additional showers and thunderstorms are expected to form along
any remnant outflow from this activity, as well as along and ahead
of a cold front currently approaching the Ohio River, based on the
latest HRRR model runs. Forecast soundings show MLCAPE peaking in
the 1500-2000 J/Kg range with fairly steep low level lapse rates
and PWATs rising to around the 2 inch mark. These parameters are
favorable for a few storms to produce wet microbursts with
potential of damaging winds and maybe some small hail. However,
mid level lapse rates will be very weak around 5.5 C/km or less
with deep layer shear also weak at 25 knots, which should help
keep the strong to severe storm threat isolated. SPC continues to
highlight our area in a marginal risk for severe storms today
which seems reasonable. Cloud cover and precip will keep temps
down a degree or two from yesterday`s readings, especially across
our northwest counties, but it will still get quite hot with highs
reaching around 90 on the Plateau and mid to upper 90s elsewhere.
&&
.LONG TERM...
(Monday through next Sunday)
Issued at 1120 AM CDT Sun Jun 23 2024
Front will pass through the area tonight with a drier and
slightly cooler airmass filtering in behind the boundary for
Monday, with highs a couple degrees lower than today. However, we
will heat right back up on Tuesday as upper ridging builds back
in aloft, with highs in the 90s anticipated for nearly everyone
once again. A much stronger upper level trough and associated cold
front is shown by guidance to dig southward out of the Great
Lakes on Wednesday into Wednesday night, bringing our best chance
for showers and storms over the next week with high chance to
likely pops. Forecast soundings for Wednesday show weak MLCAPE for
late June between 1000-1500 J/Kg, but also show a bit stronger
deep layer shear and slightly steeper lapse rates than we will see
today, along with considerable dry air aloft and DCAPE over 1000
J/Kg. Therefore, a few strong to severe storms with damaging
microbursts winds and small hail appear possible once again, and
I`d expect SPC to highlight our area in marginal risk on their new
Day 3 outlook tonight.
After the wet Wednesday, we dry out again for Thursday but will
also see much cooler temperatures in the wake of the front pushing
through with highs only in the mid 80s to low 90s. Unfortunately,
this "cooldown" will be short-lived as an H5 ridge strengthens
significantly across the southern Plains into the Southeast with
heights rising to around 597dm. This will cause temps to soar back
into the mid to upper 90s west of the Plateau, and a few
locations could hit the 100 degree mark. 12Z guidance differs next
weekend on timing and how far south a front makes it into our
area, but due to the strength of the upper ridge forecast it will
likely struggle to make much headway into the midstate.
Nevertheless, pops will be on the increase by late weekend with
temperatures potentially "cooling" back down somewhat again.
&&
.AVIATION...
(00Z TAFS)
Issued at 610 PM CDT Sun Jun 23 2024
A few remaining showers and thunderstorms will move east of I-65
through 03Z. These will mainly affect KSRB and KCSV. The gusty
afternoon winds will subside and turn more northerly overnight as
an upper level cold front passes through middle TN. VFR conditions
expected outside of any brief thunderstorms at SRB and CSV. With
winds going close to calm overnight there could be some patchy river
fog...especially over the Plateau. VFR skies tomorrow with
northerly winds 10 kts or less.
&&
.PRELIMINARY POINT TEMPS/POPS...
Nashville 72 92 70 98 / 20 0 0 0
Clarksville 69 91 69 96 / 10 0 0 10
Crossville 66 84 59 89 / 70 0 0 0
Columbia 70 94 67 98 / 20 0 0 0
Cookeville 67 85 63 91 / 60 0 0 0
Jamestown 67 83 61 90 / 60 0 0 0
Lawrenceburg 69 92 66 96 / 30 0 0 0
Murfreesboro 70 92 66 97 / 40 0 0 0
Waverly 69 92 69 97 / 10 0 0 0
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE.......Baggett
SHORT TERM...Shamburger
LONG TERM....Shamburger
AVIATION.....12
Area Forecast Discussion
National Weather Service Pocatello ID
200 PM MDT Sun Jun 23 2024
.SHORT TERM...Tonight through Monday night. Upper ridge remains in
place with hot, windy, dry conditions today. Winds have been slow
to pick up across the northern Snake Plain, but are starting to
see early afternoon gusts reaching 40 mph. Peak winds should be
approximately 3p-7p today. Wildfire in SW Idaho was quite
prevalent on yesterday`s satellite imagery, with some activity
noted into early afternoon today. Allowed HRRR smoke/haze to
populate short term grids, with plume extending NE across portions
of the central mountains through tonight. Monday pattern looks
similar, albeit slightly cooler and slightly less windy. DMH
.LONG TERM...Tuesday through next Sunday.
Dry conditions and warmer than average temperatures will persist
well into next week as high pressure pushes daytime highs 10 to 15
degrees above climatological norms. Tuesday will be the hottest day
of the extended period, with widespread highs reaching into the low
to mid-90s across the Snake Plain and eastern Magic Valley, as well
as low elevations further south, with 60s and 70s in the mountains
and 80s in mountain valleys. Elevated upper-level flow will support
breezy surface conditions over the Snake Plain daily each afternoon
throughout the week, where sustained winds will run around 20 mph
with gusts over 30 mph. An upper low will move onshore on Thursday,
with the associated frontal passage bringing advisory-level winds of
30 to 50 mph. Limited moisture will predominately remain further
north in the ID panhandle, although chances for isolated showers and
thunderstorms will exist across extreme SE Idaho. The National Blend
does include low-end PoPs up to around 30% generally south and east
of the Snake Plain. Daytime highs will return to within several
degrees of normal on Thursday and Friday. Models show the ridge
rebounding on Saturday, with the NBM featuring a ten degree increase
in high temperatures between Friday and Saturday ahead of an
approaching trough early next week. Cropp
&&
.AVIATION...
VFR conditions forecast with mostly clear skies and dry conditions
under high pressure. Elevated winds will be the main impact today
and Monday, with SW sustained winds 10 to 20 kts and gusts 20 to 30
kts. There is potential for smoke from local fires to lead to
reductions in visibility. Cropp
&&
.FIRE WEATHER...
Dry conditions and seasonably warm temperatures will persist through
the first half of next week with daytime highs running 10 to 15
degrees above normal. Minimum humidity will range 10 to 20 percent
through mid-week. Furthermore, elevated upper-level flow will
support breezy surface conditions over the Snake Plain daily each
afternoon throughout the week, with sustained winds reaching or
exceeding 20 mph and gusts ranging 30 to 40 mph. A system will bring
a brief reprieve Thursday through Friday along with slight chances
for isolated showers and thunderstorms, dropping temperatures back
to within a few degrees of normal and helping to increase min RH a
bit. Warmer temperatures will return for the weekend with high
pressure returning on Saturday. Cropp
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$