Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 04/08/24
Area Forecast Discussion
National Weather Service La Crosse WI
1032 PM CDT Sun Apr 7 2024
.KEY MESSAGES...
- Periodic showers from tonight into Monday morning.
- A small chance to see the solar eclipse south of Interstate
90.
- More rains chances from Monday night into Tuesday and from
Wednesday afternoon into Thursday night.
- Much warmer for the Weekend
&&
.DISCUSSION...
Issued at 114 PM CDT Sun Apr 7 2024
Tonight into Monday morning - More showers
The 500 mb closed low will move slowly northeast and north from the
Central Plains into the Minnesota and the Dakotas. At the same time,
a shortwave trough will be rounding the southeast and east periphery
of this low. This will bring additional showers to the forecast
area. The 07.12z HREF still shows some surface-based CAPE up to
100 J/kg in northeast Iowa and parts of southeast Minnesota, so
cannot rule out an isolated storm this evening. The CAMS are in
good agreement that by Monday morning that the showers will be
primarily north of Interstate 90.
Monday Afternoon - Still a small chance to see the solar eclipse
south of Interstate 90
Still seeing the potential for maybe some breaks in the clouds
mainly south of Interstate 90. Most of the clouds will be between
850 and 800 mb, so there might be a chance that these clouds could
become open cellular with time. Will this be during the eclipse
is uncertain. In addition, the HRRR tries to generate some
scattered showers during the eclipse. Meanwhile, the remainder
of the CAMS keep the area dry.
The 07.12z HREF total cloud cover has the mean between 90 and
100 percent north of Interstate 90. In addition, there is rather
tight difference between the 25th and 75th percentiles, so
confidence is rather high that it will likely remain cloudy in
these areas. The mean total cloudiness along the Interstate 90
corridor are running from 66% at Mauston, WI to 73% at La
Crosse, WI, and 83% at Rochester, MN. The difference between the
25th and 75th percentiles are more widespread east of La Crosse
with up to a 90% difference over by Mauston, WI and just a 10%
difference in Rochester. Further south across northeast Iowa and
southwest Wisconsin, the mean clouds range from 60 to 80%. This
is also where the greatest uncertainty occurs with rather large
differences between the 25th and 75th percentiles, so the
confidence for any clearing remains very low.
If you want to see the eclipse, the highest chances near us is from
Omaha, NE to the Quad Cities IA/IL into southwest Lower Michigan and
northern Indiana. These areas have a mean total cloud of up to 10%
and the 10th to 90th percentile (80% of the HREF ensemble) are
primarily within 20% of each other, so there is rather high
confidence that it will be mostly sunny to sunny in these areas.
High temperatures on Monday will range from the lower 50s to lower
60s.
Monday Night into Tuesday - More rain chances
Another shortwave trough will move through the region. Like the past
couple of days, the highest chance of rain 20-40% will be along and
north of the Interstate 90 corridor. With many of the deterministic
and CAMS trending drier on Tuesday, we might end up with a drier day
on Tuesday.
High temperatures on Tuesday will range from the lower 50s to lower
60s.
Wednesday Afternoon into Thursday Night - Additional rain
chances. Highest chances (40-60%) on Thursday.
A northern stream 500 mb trough will be moving east through the
Upper Mississippi River Valley. Unlike the past couple of days, this
trough looks to be much deeper as a result it looks like most of the
area will see a chance of showers. The 07.13z NBM probabilities of a
0.01 inches or greater is up to 20% on Wednesday afternoon and
anywhere from 50 to 70% for Thursday. If the trend continues for
Thursday, we will likely have to raise the precipitation chances by
20 to 40% than current values.
High temperatures will be in the 60s on Wednesday and with more
clouds expected on Thursday high temperatures will be in the mid-
and upper 50s.
Friday through Sunday - Much warmer for the weekend
An upper level ridge will build across most of the central US. This
will result in dry weather and unseasonably warm temperatures. High
temperatures will range from the mid-50s to lower 60s on Friday and
be in the 60s and 70s for the weekend. The highest probabilities
(50 to 60%) for 70s will be along and south of Interstate 90.
&&
.AVIATION /06Z TAFS THROUGH 06Z TUESDAY/...
Issued at 1032 PM CDT Sun Apr 7 2024
Lower than average confidence exists through this TAF period,
especially with ceilings. Showers will continue to become more
scattered overnight with mainly dry conditions for Monday at
KLSE/KRST. Scattered additional showers are possible Monday
evening. Easterly winds will shift southerly and then
southwesterly into Monday, gusting to 20-25 kts at times on
Monday. Periods of MVFR to IFR ceilings are likely through the
TAF period, with the highest chances at KLSE (60-90%) from
around sunrise through mid-afternoon. IFR ceilings are possible
(40-70% chance) at KRST through the morning on Monday before
some improvement is more likely to occur. However, some
variability in ceilings is likely over the coming 24 hours as a
low pressure system impacts the region.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
IA...None.
&&
$$
DISCUSSION...Boyne
AVIATION...JM
Area Forecast Discussion
National Weather Service Cleveland OH
905 PM EDT Sun Apr 7 2024
.SYNOPSIS...
A warm front approaches from the west tonight and lifts
northeast across the area on Monday. A cold front moves into
the region on Wednesday. Low pressure over the lower
Mississippi Valley deepens as it lifts northeast along this
cold front across the Ohio Valley and Great Lakes regions on
Thursday and Thursday night.
&&
.NEAR TERM /THROUGH MONDAY NIGHT/...
9:00 PM Update...
Increased cloud cover for the overnight period. For the eclipse
cloud cover forecast, not a whole lot has changed. We were able
to get a glimpse at some of the 18Z model guidance and here are
some of the main points we`re seeing the latest guidance:
-Confidence is increasing in low clouds associated with the warm
front remaining in Northwest Pennsylvania, with an area of
overcast skies becoming more likely. This could extend into the
far eastern tier of Northeast Ohio counties (e.g. Ashtabula,
Trumbull, and Mahoning but we`ll see. Areas along and west of
I-77 should be cleared of the warm front low clouds.
-Confidence is also increasing in areawide upper-level cirrus
overspreading much of the region (although perhaps less so for
Toledo and vicinity area). The 18Z HRRR/NAM and 21Z RAP are
showing enough moisture centered on the 300mb layer for some
cirrus, and you can actually currently observe this on
satellite over southern Arizona/New Mexico. Even if the cirrus
is technically "overcast", it shouldn`t be thick enough to
completely obscure the eclipse for those of you not blocked by
remaining low-level clouds, although it may not necessarily be
as clear of a view as perfect blue skies.
Previous Discussion...
Gradually increasing mid- and high-level cloud cover is
expected this evening into the overnight hours. As a warm front
moves closer to the region, am expecting it to interact with a
700mb jet that pushes into southern Ohio overnight. Expect to
see some rainfall develop with the better lift but it will be
light. Rainfall amounts should be around a tenth of an inch or
lower with decreasing amounts across NE OH into NW PA as drier
air evaporates some of the rainfall.
Lower level cloud cover is expected to decrease from west to
east through the morning with locations near the OH/PA border
seeing them linger into early/mid afternoon. High level cloud
cover will be on the increase through the afternoon but does not
look to be opaque. So at this point, locations near and east of
I-77 may have limitations with the lingering lower cloud cover
but it will be decreasing into the evening. Locations west of
I-77 should see some clouds but they look to be thin.
Temperatures tonight remain well above freezing tonight with
lows at most locations in the 40`s. Thinning clouds and
increased southerly winds will help nudge temperatures into the
60`s to lower 70s across Ohio. A bit cooler across NW PA with
upper 50`s to lower 60`s common.
By Monday night we will begin to see the cloud cover thicken and
lower as the the next are of low pressure approaches from the
Southern Plains. We are expecting to remain dry through the
night. The increasing cloud cover and light southerly winds will
combine to keep lows in the mid 40`s to around 50.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
The beginning of an active several days of weather is expected this
period. A cold front will slowly cross the area late Tuesday through
early Wednesday, with a shortwave embedded in the sub-tropical jet
stream lifting northeast through the Ohio Valley Tuesday afternoon
and evening. The combination of these features should lead to a
period of shower and thunderstorm chances, especially Tuesday
afternoon through the first half of Tuesday night. The greatest rain
chances and QPF will likely be across our southeastern counties due
to influence from that Ohio Valley shortwave. As the cold front sags
southeast later Tuesday night and as we lose lift behind the
shortwave rain chances should diminish from northwest to southeast.
The QPF with system should be light to moderate, with multi-model
ensembles (the NBM) depicting just a 10-20% chance of over 0.50" of
rain generally south of the Ohio Turnpike and minimal odds (<5%) of
over 1.00" of rain. This means renewed flooding isn`t too much of a
concern, though this rain could help keep things saturated ahead of
more rain later in the week. We are not currently outlooked for a
severe weather risk Tuesday. With moderate flow aloft and a weak
elevated mixed layer (EML) overhead on Tuesday there may be a
conditional risk for a few stronger thunderstorms as the cold front
pushes in from the northwest late in the afternoon, though this
seems to be on the less likely side and would depend on temperatures
warming enough to develop a sufficient amount of instability.
We look to reside between systems for most of Wednesday and should
be mainly dry, though do hang on to a mostly cloudy forecast with a
low shower chance (especially south) through the day as it`s
uncertain exactly how much the cold front can clear the area by
early Wednesday and how quickly moisture return begins ahead of the
next system. Speaking of, rain chances begin ramping up notably from
the southwest late Wednesday night, discussed in more detail below.
Highs on Tuesday currently range from the upper 60s in Northwest PA
to the lower 70s for much of our OH counties, though this could
trend either way depending on how quickly showers spread in. Lows
Tuesday night fall into the upper 40s or 50s. Wednesday should be a
bit cooler than Tuesday, mainly in the 60s, with lows Wednesday
night again looking to settle into the upper 40s or 50s.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
A full-latitude trough is expected to carve out over the Plains
Wednesday into Thursday as a rather potent polar jet shortwave dives
in and phases with a closed low in the sub-tropical jet stream. This
trough is expected to take on a negative tilt while shifting east-
northeast towards the Great Lakes. As this occurs, low pressure that
will develop over the lower Mississippi Valley Wednesday is expected
to lift northeast into the central or eastern Great Lakes Thursday
into Thursday night before slowly exiting northeast into southern
Canada Friday into Saturday. Since yesterday, model agreement on the
track, timing, and strength of the low has generally improved some
though some disagreement regarding all three of those variables does
remain. Given how robust the two pieces of energy phasing together
over the central U.S. appear to be and what will be a large warm
sector with unusually high moisture (per precipitable water
standardized anomalies) there are arguments for an amplified
solution, which would point to a stronger, slightly slower and
farther west system if a full phase occurs, in line with the 12z GFS
and European models. The pattern over the western U.S. appears a bit
progressive which could lead to a later phase and more progressive
system. Will need to monitor how well the two shortwaves will phase
over the central U.S. for possible trends in either direction.
In terms of sensible weather, a round of wet weather is in store
late Wednesday night and Thursday with thunder possible on Thursday.
Steadier rain may exit northeast Thursday night into Friday, though
at the least some wrap-around showers appear likely at times through
Friday. By Saturday the system should exit enough to allow the
region to dry out more completely. Per the NBM, the odds of over
0.50" of rain with this system range from about 75 to 90% across our
area, lowest near Erie and increasing to the south. Odds of over
2.00" of rain are as high as 10-20% from Sandusky to Millersburg
Points west and are a bit lower farther northeast. While it`s good
that the odds of over 2.00" of rain are generally low, even 1.00-
2.00" of rain could pose additional minor to moderate river flooding
concerns given the amount of rain we`ve seen lately, especially at
the typical points that flood most often.
Another concern will be synoptic winds if we do see the low on the
deeper side of solutions (near or below 980mb)...the greatest
concern will be on the backside of the low on Friday, when some
solutions depict a 40-50 knot 850mb jet overhead in strong cold air
advection. This could lead to gusty winds, possibly reaching
advisory-criteria for parts of the area. The NBM depicts 20-40% odds
of gusts exceeding 45 MPH across most of the area on Friday but with
minimal odds (<10%) of gusts exceeding 60 MPH. Will also need to
watch the eastern lakeshore on Thursday in south-southeast flow for
stronger downsloping winds, though guidance disagrees on if the low
will be strong enough to bring a risk of damaging downslope winds.
Otherwise, the deep low and robust wind fields could lead to a risk
of stronger thunderstorms on Thursday ahead of the low`s warm front
in the warm sector...however, given discrepancies on the track,
timing, and intensity of the low the confidence in any severe
weather risk is minimal at this time. Some models do not break us
into the warm sector or keep us too cloudy/rainy/cool to develop
sufficient instability even if we do get into the warm sector.
Temperatures will be a bit warmer than average for Thursday ahead of
the low, a bit cooler than average for Friday behind it, and
rebounding back towards normal on Saturday as the low exits.
&&
.AVIATION /00Z Monday THROUGH Friday/...
VFR conditions are expected through the TAF period. However an
approaching warm front will bring a period of light rain across
the area tonight through Monday morning. Ceilings will lower
and thicken overnight but expect ceilings to bottom out at
3500-5000 feet before dissipating from west to east through the
day Monday.
Southeast winds around 8-10 knots tonight become south Monday
morning and then southwest by early Monday afternoon. Gusts to
20 knots are possible Monday afternoon.
Outlook...Non-VFR is likely with periods showers and
thunderstorms Tuesday through Friday.
&&
.MARINE...
East-northeast winds will increase to 14 to 18 knots over the
western and central basins for a few hours this evening and may stir
up some 2 to 4 foot waves near the islands. However, conditions will
be just shy of small craft criteria. Winds will turn southeasterly
into Monday and diminish to 5 to 10 knots by the afternoon, leading
to fairly tranquil marine conditions during the eclipse when
increased recreational traffic is likely on the lake. It`s worth
noting that air temperatures will be several degrees cooler over the
water than on land, with water temperatures in the 40s posing a
danger for anyone who goes in the water without a wetsuit.
A strong low pressure will track near or over Lake Erie late
Thursday or Thursday night before only slowly exiting to the east-
northeast Friday and Saturday. East winds will increase Wednesday
night into Thursday, shift south to southwest Thursday afternoon,
and come around to a more westerly direction later Thursday night
into Friday as the low goes by. Marine headlines are likely Thursday
night into Friday behind the low and are possible as early Wednesday
night or Thursday depending on how strong the east flow ahead of the
low is. Some model solutions with stronger lows suggest a westerly
gale is possible over the lake Friday or Friday night, with ensemble
guidance depicting a 10-30% risk over much of the lake increasing to
40-60% over the New York waters. This will be worth monitoring.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...None.
PA...None.
NY...None.
MARINE...None.
&&
$$
SYNOPSIS...Saunders
NEAR TERM...MM/Saunders
SHORT TERM...Sullivan
LONG TERM...Sullivan
AVIATION...Saunders
MARINE...Sullivan
Area Forecast Discussion
National Weather Service Austin/San Antonio TX
1023 PM CDT Sun Apr 7 2024
...New AVIATION...
.UPDATE...
Issued at 912 PM CDT Sun Apr 7 2024
Only some minor changes were made to the short-term tonight. Early
looks at the 00z HRRR and Fv3 do not show many changes. Think most of
the morning and eclipse time will remain dry before rain chances
increase in the mid to late afternoon hours. Skies are partly to
mostly cloudy with some high clouds at the present time. Latest
surface obs show the warm front remains just southeast of our area
but this should be on the move overnight as the low-level jet
increases. This will bring in low-clouds by morning. Our best hope
for eclipse viewing is still some brief breaks in the clouds at
times.
&&
.SHORT TERM...
(Tonight through Monday night)
Issued at 203 PM CDT Sun Apr 7 2024
Main Talking Points:
- High probability of poor eclipse viewing conditions continues
for nearly all of South Central TX for midday Monday.
- Slight Risk (2 of 5) of severe storms for areas along and
north of a Burnet to Georgetown line and a Marginal Risk (1 of 5)
across the rest of South Central Texas.
- Slight Risk (2 of 5) of severe storms is possible across the
eastern two-thirds of South Central Texas on Tuesday.
A Pacific front moved across the local area this morning and
produced a few showers as it was moving across the Coastal Plains.
Latest satellite images and surface observations as of 2 PM are
showing the frontal boundary pushing back to the north. This
boundary/warm front is forecast to continue to push slowly to the
north for the rest of this afternoon into Monday. Northwest to
northeast winds are forecast to switch to the east and southeast as
the boundary pushes across the Coastal Plains and the I-35 corridor
this evening into Monday. Increased moisture across the Coastal
Plains and I-35 corridor translate to increase cloud coverage
through the period in addition to the upper level moisture (high
clouds) arriving from the southwest (Central Mexico) under the
influence of a southwest flow aloft.
By Monday morning, expect mostly cloudy to cloudy skies across South
Central Texas with patchy to areas of fog mainly along and east of
Interstate 35 and the Coastal Plains. Can`t rule out some drizzle or
a stray light shower or two. As the day progresses, instability
increases as an upper level low over Arizona moves into northern
Mexico and the warm front continues to push to the north into
central Texas. We will be in the warm sector all day on Monday with
a dry-line lingering just to the west of the Rio Grande/Val Verde
County.
By the time of the total solar eclipse or around 12:30 to 1:30 PM
(local time), we have a high confidence of mostly cloudy to cloudy
skies for most of South Central Texas. Probabilities for cloudy
skies are less across the southern Edwards Plateau and Rio Grande.
As far as shower or thunderstorm activity, best probabilities are
across the Coastal Plains and I-35 corridor (50 to 70 percent)
around but mainly after the total solar eclipse. For areas along and
west of I-35 and the Hill Country, probabilities are around 20 to 50
percent) with hires models suggesting light to moderate shower
activity. Things are going to change rapidly around or shortly after
the 3 PM time window with a few strong to severe storms possible
along the I-35 corridor and the Coastal Plains. The main hazard
threat is large to very large hail. There is likely enough shear in
place across the northern part of the Hill Country (Burnet and
Williamson Counties) that an isolated tornado or two can`t be ruled
out.
Storm activity continues into the evening across the Hill Country
and then begins across the Rio Grande and southern Edwards Plateau
Monday night into the overnight hours ahead of the dry-line. Severe
weather threat continues into Tuesday across most of South Central
Texas. See the long term discussion for more details on this matter.
&&
.LONG TERM...
(Tuesday through Sunday)
Issued at 203 PM CDT Sun Apr 7 2024
An upper level low will move east into and across TX Tuesday and
Tuesday night. A dryline will move into the western part of the CWA
during the day Tuesday, and then a cold front will move in behind it
eventually overtaking it. These boundaries will move into a warm,
moist airmass and generate convection. Models forecast CAPE up to
2000 j/kg and vertical wind shear 50-60 kts which will mean some
storms could be strong to severe. The most likely threats will be
large hail and damaging wind gusts. As the front moves away Tuesday
night chances for storms will move away with it. Some showers could
linger into the day Wednesday and then dry weather will return.
Behind the cold front drier, cooler air will move in from the west.
Highs Wednesday will be around ten degrees cooler than Tuesday and
lows will be below normal in the upper 40s to middle 50s. An upper
level ridge will build over the Southern Plains keeping dry weather
in place for the rest of the week. Temperatures will gradually warm
into the weekend reaching well above normal by Sunday.
&&
.AVIATION...
(06Z TAFS)
Issued at 1018 PM CDT Sun Apr 7 2024
VFR conditions continue this evening, but a return of low-level
moisture is expected within the next several hours. Conditions will
initially be MVFR but quickly become IFR/LIFR with possible
visibility restrictions also possible. Some scattered showers will be
possible in the morning and will mention VCSH for the San Antonio
sites. Activity will push into AUS later in the afternoon and will
mention VCSH with a PROB30 group for tsra. Another round of IFR and
possible showers and thunderstorms are expected tomorrow night.
&&
.PRELIMINARY POINT TEMPS/POPS...
Austin Camp Mabry 63 83 68 79 / 0 70 60 80
Austin Bergstrom Intl Airport 60 81 68 79 / 0 70 60 80
New Braunfels Muni Airport 61 84 68 83 / 0 50 50 70
Burnet Muni Airport 58 81 66 77 / 0 60 70 80
Del Rio Intl Airport 62 89 67 93 / 0 10 40 10
Georgetown Muni Airport 59 81 67 77 / 0 60 70 90
Hondo Muni Airport 60 83 66 88 / 0 30 50 50
San Marcos Muni Airport 61 82 67 82 / 0 60 60 70
La Grange - Fayette Regional 67 82 69 80 / 0 70 60 70
San Antonio Intl Airport 64 82 68 84 / 0 50 60 60
Stinson Muni Airport 64 83 69 85 / 0 50 50 60
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Short-Term...29
Long-Term...17
Aviation...29
Area Forecast Discussion...Updated
National Weather Service Lincoln IL
748 PM CDT Sun Apr 7 2024
.KEY MESSAGES...
- Scattered storms will continue through mid evening south of
I-70, with some stronger wind gusts and small hail expected.
- Scattered high clouds are expected along the path of totality in
SE IL during the eclipse (40% sky cover). Cloud cover decreases
with northward extent on Monday at the time of the eclipse.
- Unsettled this week with rain chances Tuesday-Thursday. Rain
chances and amounts both increase with southeastward extent.
There is a 40-50% chance of total rainfall exceeding 2" south of
I-70.
&&
.UPDATE...
Issued at 748 PM CDT Sun Apr 7 2024
Still have some thunderstorms lingering south of I-70 this
evening, with a couple bands that extend back into south central
Illinois. Further northwest, skies were clear west of I-57.
Occluded front has passed Jacksonville where dew points have
dropped into the upper 20s, while remaining in the mid 50s a short
distance east in Springfield. This front will continue to push
eastward through the evening, though the lingering rain should
largely be out of the area by midnight.
In general, mostly clear skies prevail overnight, though the
clouds east of I-57 will have a more difficult time clearing out.
Latest HRRR shows low clouds (below 2,000 feet) beginning to form
toward 3 am, becoming more widespread south of I-70 by 5-6 am. In
this scenario, they should move out by mid morning, just in time
for the cirrus to arrive. Will continue to monitor this and refine
the cloud forecast as the new model guidance arrives this evening.
Geelhart
&&
.DISCUSSION...
Issued at 152 PM CDT Sun Apr 7 2024
18z surface map indicated 995 mb low pressure in northeast
Nebraska with an occluded front stretched southeast across IA
then south along the Mississippi River near St. Louis. Convergence
along that boundary allowed dewpoints to pool near 50F, and
visible satellite imagery shows an agitated cu field along the
front. The front is forecast to pivot northeast, stretching from
west central to southeast IL by late afternoon, before washing out
this evening. Still expecting isolated convection to fire in this
zone, and given near 100 J/kg of 0-3 kt CAPE and deep layer shear
near 50 kt, a few organized storms capable damaging wind gusts
and hail are possible mainly through 6-8 pm.
Ahead of this activity, current batch of elevated convection over
the central CWA has shown frequent lightning strikes and numerous
reports of pea sized hail, and brief heavy rain. This will
continue to shift east and out of the region by late afternoon.
Gustiest winds through late afternoon will be along and ahead of
the initial line of convection, with southeast winds gusting 30-40
mph. Tonight, the dry slot overspreads the area, leading to
clearing skies and lighter southeast to south winds.
Monday, eclipse day, will feature stable low levels and dry low
to mid level air, so not much in the way of diurnal cu or mid
level clouds are forecast. However, high level moisture streaming
northeast from a southern stream wave will bring an increase in
thin, high cirrus (cloud bases near 25,000 feet). This cloud layer
will be most pronounced for areas near/south of I-70 during early
afternoon, and viewing of the eclipse will depend on how thick
they ice crystals in this layer become. Farther north, lower
coverage of cirrus is forecast which should not impact viewing of
the eclipse. Otherwise, south to southwest winds gusting 15-25 mph
will be common, and temperatures will be mild with highs reaching
the low/mid 70s.
Tuesday through Thursday features an unsettled period of weather
for parts of the Midwest and Ohio Valley, as a deep and slow
moving upper low tracks from the desert southwest into the Great
Lakes. Initial shortwave disturbances ahead of the main wave look
to spread rain across areas near and south of I-70 for Tuesday and
Tuesday night. There was a notable southward shift in precip
associated with this wave by ~50 miles on today`s 12z guidance.
For Wednesday, periods of overrunning showers and storms look to
affect mainly the same areas, or slightly farther north, so we
have a gradient from dry conditions west of the IL River, to
likely PoPs south of I-70. Wednesday night and Thursday, the main
upper level energy is forecast to lift into the Mississippi
Valley, resulting in a deepening surface low tracking into the
Ohio Valley. This wave will likely spread rainfall farther west,
and latest guidance shows likely PoPs as far west as the IL River
Valley. Wrap around cyclonic flow then looks to dominate the
region Thursday night and Friday, bringing cooler air and mostly
cloudy skies. Blended guidance shows 1-2" rain totals near/south
of I-70 through the week, likely renewing another round of rising
rivers in that area.
25
&&
.AVIATION... (For the 00z TAFs through 00z Monday Evening)
Issued at 628 PM CDT Sun Apr 7 2024
Scattered showers continue to linger near KCMI, though latest
lightningcast data continues to focus any thunder threat to the
south/southeast, so no VCTS is being included in the new TAF set.
Some concern in this area toward 09-12Z for a period of MVFR
ceilings as seen by the HRRR model, though HREF ensembles are
more bullish and longer lasting.
Outside of this cloud area, main focus for Monday will be with
southwest winds increasing to about 10-12 knots by late morning.
This will linger much of the afternoon.
Geelhart
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Area Forecast Discussion
National Weather Service Louisville KY
949 PM EDT Sun Apr 7 2024
.KEY MESSAGES...
* Showers and a few embedded thunderstorms tonight as a system
works into the Upper Midwest pushing a weak boundary into the
region. Gusty winds possible with the strongest showers or
storms.
* Warm and dry for Eclipse Day. Increasing confidence in high thin
cloud cover, but still some uncertainty in how much that actually
affects viewing.
* Multiple rounds of rainfall expected starting late Monday night
into Thursday or Friday. Widespread two to three inches of rain
likely in that timeframe. Low end flood threat and conditional
strong/severe storm threat possible.
&&
.UPDATE...
Issued at 947 PM EDT Sun Apr 7 2024
Scattered convection, with some isolated strong cores, has been
moving from the Mid Mississippi Valley to the lower Ohio and
Tennessee Valleys this evening. This activity is mainly driven by
low-level warm advection along/behind the warm front and attendant
low-level jet with some help from upper-level divergence via mid-
level wave/jet. Although some radar echoes have moved over the
southern Indiana and west-central Kentucky, it is difficult to find
any accumulations in KY Mesonet given the deep dry layer anchored in
the low levels, per SDF ACARS.
Still, GLM and MRMS reflectivity mosaic at -10 degC depict a few
enhanced signals that correlate very well with effective bulk shear
of 40-50 knots and a MLCAPE gradient at the edge of the
moisture/instability axis. Given the presence of sufficient low-
level dry air, decreasing MLCAPE, and fast storm motions, current
strong convective elements should outrun the narrow instability
corridor and become mostly elevated while weakening as they continue
tracking eastward towards the forecast area. This overall trend
agrees fairly well with the latest HRRR outputs. There are,
however, a few exceptions to the previous reasoning: one being the
potential for outflow boundary interactions and subsequent storm
mergers into a linear feature (potentially prolonging storm
maintenance as seen in southern IL) and the other renewed convective
activity along the instability axis due to deep moist convergence
along the LLJ (western KY and TN). That being said, probabilities of
any severe weather threat tonight are very low to non-existent based
on SSCRAM guidance.
Rest of the forecast continues to be on track and grids were updated
with the latest obs. A thorough weather forecast for the Total
Solar Eclipse can be found below.
&&
.SHORT TERM /THROUGH MONDAY/...
Issued at 310 PM EDT Sun Apr 7 2024
Tonight...
It`s been a nice day across the area thanks to upper level ridging
directly overhead. However, our weather conditions will begin to
change for this evening as our next system approaches. To our west,
a large upper low is located over Nebraska, with the associated sfc
low trailing a cold front from the High Plains all the way to near
the Texas coastline. A warm front is also extending to the southeast
of the low, which will be our primary source for forcing later this
evening.
For tonight, as the warm front lifts northeastward into the
Tennessee Valley, isentropic ascent will promote a favorable
moisture transport axis focused on central KY and southern IN. Just
above the sfc, a LLJ will be working into the region as well, but is
expected to be weakening as it does so. We`ll see isolated to
scattered shower activity arrive from the west, and push eastward
through the overnight hours. Model soundings continue to support a
low cape high shear environment. Meager (if any) instability will
likely be set aloft thanks to a stable layer near the sfc. Still
can`t rule out some rumbles of thunder tonight, but it should be
fairly isolated. Given the wind aloft, suppose it will be possible
to have some breezy winds with any stronger cell, but severe winds
are not expected. Except for the Lake Cumberland area, we should be
back to dry wx by sunrise tomorrow. It will probably take another
hour or two after sunrise for PoPs to clear our southeastern
counties.
Solar Eclipse Discussion...
First things first, a dry forecast is set for tomorrow. What has
been the bigger focus is the cloud forecast, which has been very
complex given the limitation to forecasting the opaqueness of cirrus
clouds even just 24 hours out. Areas to the east of I-65 will have
the greatest impact to clouds, with a mix of cloud levels expected.
For areas to the west of I-65, and closer to the path of totality,
high level cirrus clouds are expected, but that does not mean it
will put a damper on the event. There`s been a lot of good
collaboration between the WFOs the last couple of days, and as a
result will keep the skycover forecast as 30-40% coverage for the
cirrus. Thin cirrus is developing over the Baja California region
this afternoon, which will eventually expand downstream and will be
overhead by tomorrow afternoon. The HREF has a good handle on this
already.
With all that said, the sky cover forecast may end up a bit light
compared to what an observer might report at an augmented airport,
but still quite generous compared to what Joe Public would perceive
while trying to view the eclipse, i.e. even if there is high cloud
cover, it`s more likely that it still won`t interfere with viewing.
Otherwise expect a mild start in the 50s with temps warming into the
70s in the afternoon, mainly after the eclipse which will likely
drop readings into the upper 60s for an hour or two.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
Issued at 310 PM EDT Sun Apr 7 2024
Monday Night through Friday...
A more unsettled and wet weather pattern will begin to take shape by
Monday night. Upper level flow over the Ohio and Tennessee Valleys
will take on a southwesterly component as an upper level low (ULL)
swings into the Desert Southwest. At the surface, a frontal boundary
will slowly sink southward toward the region before transitioning to
nearly quasi-stationary by midweek, while various perturbations
within the active southwest flow ride over or near the frontal
boundary. The first wave looks to arrive late Monday night into
Tuesday, with subsequent waves continuing into Thursday before the
ULL is swept up within the main flow and carried northeastward. Wrap-
around precip on the backside of the low could continue as late as
Friday, depending on the track and evolution of the system. A couple
of weather related impacts could unfold from this setup, mainly in
the form of marginal/minor flooding and a conditional severe threat.
Flood Threat: There is still a bit of spread in the model guidance
on the exact amounts our region will see, but GEFS and ECMWF
ensemble means paint 2-3+ inches west of I-65 and 1.5-2.5 inches
east of I-65 for the Monday night through Friday timeframe. Not all
of this rain will fall continuously during this period, as we`ll see
breaks in between waves of rain. The heaviest rains likely arrive
Wednesday night into Thursday and could include embedded
thunderstorms. Should the higher end amounts verify, we could have
some low-end, minor/nuisance flooding by Thursday into Friday.
Several river sites (generally west of I-65) may also climb into
action or minor flood stage, though much of this depends on how much
rain falls in those river basins. Confidence in the rainfall totals
and potential for low-end flooding is low to medium.
Severe Threat: There is a conditional window Wednesday night into
Thursday that a low-end severe threat could develop. Models prog a
surface low near the ArkLaTex region Wednesday to deepen and lift
toward our region Wednesday night. Low level moisture will be drawn
poleward as the low approaches, likely resulting in a narrow tongue
or corridor of ~60 degree dewpoints ahead of a frontal boundary.
Model soundings show strong shear profiles but poor low/mid level
lapse rates ahead of the frontal boundary with minimal instability,
which would generally result in no severe weather. However, if we
were to realize even small amounts of instability (say, models
underestimate low level moisture return), there could be a
conditional threat for strong/severe storms with an isolated wind
and tornado threat. Confidence in this threat and scenario is low,
as we also need the surface low to generally track west of the
region for us to be within the warm sector and have a severe threat
(some models/members keep the low east of the region). For what it`s
worth, the CSU-ML model and CIPS Analog threat guidance indicate
some potential for severe weather for this timeframe.
Friday Night into the Weekend...
Upper level ridging will build in behind our system and result in
warm and generally dry conditions for the weekend, allowing us to
dry out for a bit before any more potential systems could impact the
region by early next week.
&&
.AVIATION /00Z TAFS THROUGH 06Z TUESDAY/...
Issued at 736 PM EDT Sun Apr 7 2024
Impacts/Confidence:
- Low confidence in shower-/storm-induced impacts this evening
- High confidence in LLWS tonight for SDF/BWG/LEX/RGA
- Medium to high confidence in MVFR ceilings late tonight
- Low confidence in IFR ceilings Monday morning.
Discussion...Although terminals will start off under VFR conditions
this evening, broken layer of low-level clouds will most likely
bring MVFR ceilings later tonight. Radar and satellite imagery
highlight an area of widely scattered showers and isolated storms
moving towards the forecast area along a surface front. In addition,
there are a couple of strong thunderstorm that area being monitored
closely. However, expectations are for this activity to decrease in
coverage and intensity as it progresses eastward due to loss of
instability. As a result, included some -RA and VCTS for the
westernmost terminals with the possibility to amend if needed.
For the first half of tonight, the presence of a LLJ translating
through the area will favor LLWS at all sites, except at HNB, with
some lingering isolated showers. Then, forecast soundings show
saturated conditions in the lowest kilometer with weak capping
inversion above which support model output to represent a broken to
overcast cloud layer. Therefore, there is at least medium confidence
of MVFR ceilings moving west to east during the second half of the
night and towards the early morning hours. Furthermore, NBM is
showing low probabilities for HNB and SDF of IFR ceilings for a
brief period after sunrise, but was not included with this issuance
given the low confidence. Finally, ceilings will begin to lift after
15/16Z with VFR conditions and light SSW winds afterwards.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...None.
IN...None.
&&
$$
UPDATE...ALL
SHORT TERM...CJP
LONG TERM...DM
AVIATION...ALL
Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
1047 PM CDT Sun Apr 7 2024
.UPDATE...
Issued at 613 PM CDT Sun Apr 7 2024
Storms ongoing in far eastern portions of county warning area and
should exit by 7 PM. Otherwise, winds will diminish by sunset with
clear skies overnight.
Byrd
&&
.KEY MESSAGES...
- The threat for isolated severe thunderstorms will continue
mainly over southwestern Illinois through early this evening.
Large hail and damaging wind gusts are the primary threats.
- Confidence remains high (90%+) in warm and dry weather across
the region for tomorrow`s total solar eclipse. It still looks
likely (50- 60%) that there will be at least some high clouds
over our CWA during the eclipse, however confidence in the
coverage and the thickness of these clouds still remains low
(30%).
- An active pattern will bring the potential (up to 70%) for
multiple rounds of rainfall mainly across southern/southeastern
portions of the area Tuesday into Thursday.
&&
.SHORT TERM... (Through Late Monday Night)
Issued at 231 PM CDT Sun Apr 7 2024
An upper-level low is wrapping up and closing off over the Great
Plains per recent water vapor imagery. Surface observations show its
associated surface low is occluding over Nebraska. Locally, our
focus is on convection along the low`s cold front/dry line/occlusion
that is currently along the Mississippi River in northeastern
Missouri/west-central Illinois extending south-southwestward into
southeastern Missouri. Current SPC Mesoanalysis shows pockets of up
to 250 J/kg of MLCAPE immediately ahead of the boundary and 40-60
kts of effective bulk shear. Instability thus far has been tracking
lower than expected, likely due to a combination of earlier cloud
cover and dew points being just a couple of degrees lower than
originally expected. This has so far limited updraft strength;
however, both the HRRR and the RAP have a plume of roughly 500 J/kg
of MLCAPE spreading northward across southwestern Illinois ahead of
the boundary later this afternoon and early evening. When paired
with the aforementioned shear, this will lead to an isolated threat
for severe thunderstorms capable mainly of damaging wind gusts and
large hail over portions of southwestern Illinois through about
00z/7pm when convection clears the CWA to the east. A brief tornado
or two can`t be ruled out still, but model hodographs are more
straight than curved, indicative of just enough low-level shear for
a very low tornado threat.
Tomorrow, the closed low will be slowly spinning northward through
the Upper Midwest as the surface low follows a similar trajectory.
Thanks to the cold front/dry line today, boundary layer and mid-
level moisture will have been scoured from the area, leading to a
dry day. Southerly to southwesterly surface winds will advect warm
air into the CWA, with temperatures expected to top out in the mid
to upper 70s. Some locations across southeastern Missouri within the
path of totality for the solar eclipse may see afternoon highs top
out around 80 degrees. While the lack of moisture in the lower
portion of the atmosphere means that cumulus is very unlikely during
the eclipse, southwesterly flow aloft and a deepening low over the
Southern Plains produces concerns regarding cirrus streaming into
the area during the late morning and afternoon. A majority of
deterministic and ensemble guidance shows a layer of saturation
around 300 mb, leading to relatively high confidence that we`ll see
at least patchy cirrus across the area during the eclipse. However,
guidance still varies on the magnitude and depth of saturation,
leading to continued uncertainty in how widespread or dense the
cirrus might be.
Elmore
&&
.LONG TERM... (Tuesday through Next Sunday)
Issued at 231 PM CDT Sun Apr 7 2024
Early Tuesday morning, a western trough will be in the process of
ejecting out into the Southern Plains as a shortwave streaks through
the Ohio Valley. This shortwave will combine with a low-level jet
nosing into the Ohio Valley to support a broad area of showers and
embedded thunderstorms during the morning hours. Ensemble
probabilities are around 60-70% that southeastern Missouri and
southwestern Illinois will see rainfall with this first round of
rain, with probabilities dropping off rapidly north-northwestward
from there. As the low-level jet weakens during the late morning and
the shortwave continues to move east-northeastward, rain chances
will diminish, with guidance consensus pointing to much of the CWA
will be dry through the day.
Late Tuesday into Wednesday, both deterministic guidance and
ensemble clusters show the western trough becoming more progressive
and moving toward the Mid-South and Ohio Valley. Its surface low
will follow a similar trajectory, and while ensembles have
increasingly converged on a track from the Mid-South through the
Ohio Valley south of the CWA, there is still enough variability in
the track due to subtle differences in the phasing of the trough to
make how far north rain chances stretch into the CWA uncertain. As
with the early Tuesday system, ensemble-based probabilities are
highest (70%) across southeastern Missouri and southwestern Illinois
decreasing to 10-20% across northeastern Missouri during the day on
Wednesday.
As the surface low moves northeastward into Thursday, deterministic
guidance depicts a shortwave digging southward along the backside of
the trough as it departs the region. This shortwave will utilize
moisture on the backside of the low to keep the chance (30-60%) for
light rain going across the region through Thursday. Temperatures
will have cooled starting Wednesday closer to seasonal normals
thanks to the mid-week system bringing deep northerly to
northwesterly flow to the region. However, temperatures will begin
to creep warmer to end the week and start the weekend as an upper-
level ridge builds into the Midwest per guidance consensus.
Elmore
&&
.AVIATION... (For the 06z TAFs through 06z Monday Night)
Issued at 1044 PM CDT Sun Apr 7 2024
Most of the area will experience VFR flight conditions tonight
through Monday with an increase in high clouds Monday morning into
the afternoon and evening. KCPS is a terminal where there is some
uncertainty tonight as there is some potential for fog
development. At this time confidence is too low to include fog but
it will need to be monitored carefully.
Glass
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...None.
IL...None.
&&
$$
WFO LSX
Area Forecast Discussion
National Weather Service Memphis TN
959 PM CDT Sun Apr 7 2024
...New UPDATE...
.UPDATE...
Issued at 959 PM CDT Sun Apr 7 2024
Scattered thunderstorms continue along the I-40 corridor and
points south at midevening, aided by by a 40-45KT low level jet
evident on KGWX radar. Winds were sufficiently veered above a
shallow surface inversion to support organized storms. SPC/RAP
mesoanalysis page depicts mixed-layer CAPE around 1000 J/kg in the
current storm corridor, decreasing to less than 200 J/kg over
northeast MS.
As we proceed into the overnight, midlevel height changes will
tend toward neutral, behind a trof axis lifting into the Ohio and
Tennessee River Valleys. As this occurs, southward progress of
storms will slow over the Midsouth, as the corridor of low level
convergence parallels the midlevel flow. Storms will show a
greater tendency to train under this scenario, but waning
instability over north MS should limit the severe threat and
rainfall rates. 250mb jet speeds will decrease from an early
evening high of 140 knots down to around 80 kts toward daybreak.
Decreasing kinematic and instability aside, showers and sub-
severe storms will continue south of the I-40 corridor overnight,
sustained through daybreak by a gradually weakening low level
jet.
A surface dryline will edge into northeast AR overnight, but make
little further progress east on Monday.
PWB
&&
.SYNOPSIS...
Issued at 305 PM CDT Sun Apr 7 2024
A frontal boundary will move into the region tonight with showers
and thunderstorms developing ahead of it. A few strong to severe
storms are possible. The main axis of clouds and rain chances will
extend from central Mississippi into northern Alabama on Monday
with good eclipse viewing conditions expected in the area of
totality. Unsettled weather will return Monday night and continue
through Thursday. A flooding threat will develop as multiple
rounds of showers and thunderstorms impact the region.
&&
.DISCUSSION...
(This evening through next Saturday)
Issued at 305 PM CDT Sun Apr 7 2024
A complex weather pattern has set up across the Mid-South this
afternoon as a warm front is moving into middle Tennessee. Behind
the warm front, dewpoints range from the mid 50s to mid 60s. A
weak cold front extends front eastern Missouri south through
central Arkansas and into far east Texas. Temperatures are not
that much cooler behind this front but dewpoints lower
significantly into the mid 20s to mid 30s. A few showers and
isolated thunderstorms have developed ahead of this cold front
across portions of east Arkansas. A strong or severe thunderstorm
could develop later this afternoon with damaging winds and large
hail being the main threats. Also, windy conditions have developed
across portions of northeast Arkansas where the Wind Advisory
remain in effect until 5 PM CDT.
As this cold front moves east into the Mid-South tonight,
additional showers and thunderstorms are possible mainly east of
the Mississippi River. Temperatures tonight will be quite mild for
early April with lows Monday morning in the upper 50s to lower
60s. The cold front should weaken as it moves south Monday morning
with a few scattered thunderstorms possible for areas south of
I-40. With drier air moving into portions of northeast Arkansas on
Monday, conditions are looking more favorable for viewing the
solar eclipse along the path of totality. Temperatures will be on
the warm side on Monday with highs in the mid 70s to around 80
degrees.
By Monday night, the boundary will start to lift back north with
showers and thunderstorms becoming more widespread. A few of the
thunderstorms may be strong to severe Monday night with gusty
winds and hail as the main threats.
By Tuesday, a cold front will be over northwest Arkansas and will
head slowly toward the Mid-South with more showers and
thunderstorms. Low pressure develops along the front along the
Texas/Louisiana border by Wednesday morning and moves into west
Tennessee by Thursday morning. This will enhance the development
of thunderstorms for Tuesday night through Thursday. While strong
to severe thunderstorms can`t be ruled out, the main threat will
be heavy rainfall. Between tonight and Thursday, much of the Mid-
South could see between 4 and 8 inches of rain during this
period. The most likely time for heavy rainfall will be from
Tuesday night through Wednesday and a Flood Watch may be needed
for this time period.
As the surface low pulls out of the region by Thursday evening,
the threat of rain will end. Cooler and drier air will move into
the region with dry weather expected for Friday and Saturday.
Temperatures will be near normal for Thursday night through Friday
night with warmer weather expected on Saturday.
&&
.AVIATION...
(00Z TAFS)
Issued at 646 PM CDT Sun Apr 7 2024
Corridor of scattered discrete TSRA continues to edge closer to
MEM. Short range CAMs, including the HRRR have struggled a bit
with respect to initiation and subsequent coverage. Nonetheless,
expect the primary convective corridor to shift south of a MEM-MKL
line after 06Z, along and in advance of a surface dryline.
The dryline will mix north as warm front on Monday, with MVFR in
the morning, and isolated SHRA/TSRA in the late afternoon and
evening. Highest TSRA chances for MEM lie beyond 06Z/09, in the
pre-dawn hours Tuesday, but isolated TSRA will be possible during
the Monday evening inbound push.
PWB
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...None.
MO...None.
MS...None.
TN...None.
&&
$$
PUBLIC FORECAST...ARS
AVIATION...PWB
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
643 PM CDT Sun Apr 7 2024
.KEY MESSAGES...
- Additional rounds of rain arrive later this afternoon and
evening, with the chance for thunderstorms in southern
Minnesota. Scattered showers possible through early Tuesday.
- Following a cool Sunday, temperatures will rebound to the 50s
and 60s this week. Chance for showers late Wednesday into
Thursday.
&&
.DISCUSSION...
Issued at 215 PM CDT Sun Apr 7 2024
Initial band of warm advection driven rainfall has expanded in
coverage and spans over much of the region early this afternoon.
Periods of moderate, to at times heavy rain have been the theme
for most locations. There have been a few exceptions, particularly
across southern Minnesota where GOES-East lightning mapper
technology captured several strikes within the elevated convection
on the southern edge of the precipitation shield this morning.
These cells remained fairly weak overall, however we did receive
a report of pea-sized hail near Mankato just prior to 9 AM.
Conceptually this makes sense, given the steep (8-8.5 deg/km)
mid-level lapse rates depicted on SPC Mesoanalysis across
southwest Minnesota at the time. On the flip side, locations to
the far northwest near AXN have reported a changeover to
snow/wintry mix, given the wet-bulb scenario discussed over the
past few forecast periods. The expansive band of precipitation
will continue to traverse northward in the next few hours,
before CAMs bring lull in the rainfall for the start of the
evening, which is supported by a break in the precipitation
across southern Minnesota and northern Iowa at this hour.
Low pressure swirling over northern Nebraska will pinwheel northeast
through northern Iowa/southern Minnesota this evening through early
tomorrow morning. Additional rounds of rain and perhaps a few
thunderstorms will develop ahead of the surface low, which is
depicted by clusters of cells in the latest CAM suite. RAP
forecast soundings have continued the trend of skinny CAPE
profiles building ahead of this convection for sites in southern
Minnesota. It`s possible a few rumbles of thunder may be heard
as far north as the Twin Cities metro through midnight. Outside
of the marginal instability, the thermodynamic environment
looks quite weak, which is no surprise given the widespread
cloud cover seen on GOES-East visible satellite. The second
round of wet weather will once again begin across southern
Minnesota and progress northward well into the overnight. As the
upper-low pivots northeast towards Lake Superior, wrap around
rain showers will remain in play through at least Monday
evening, and possibly into the first half of Tuesday. When all
comes to an end, a fresh 0.5"-1" of rain is expected to have
fallen across the area which comes at a great time given the
recent dry weather (and critical fire weather days).
Monday is solar eclipse day, however the forecast remains quite
unfavorable for viewing across most of Minnesota and western
Wisconsin due to the expected cloud cover and shower chances.
Temperatures are forecast to warm over the next few days, with highs
in the low 50s Monday, the upper 50s/low 60s on Tuesday, and well
into the mid 60s on Wednesday. Winds are forecast to be much lighter
through mid-week, which is will be a nice pairing with the
temperatures for any outdoor activities. A trough will dig southeast
out of Canada into the Upper Midwest late Wednesday into Thursday,
which will bring the chance for passing showers and "cooler"
temperatures, which will fall back in the 50s on Thursday per the
latest NBM. Shower chances will end by Friday and temepratures will
return to the upward trend, with highs in the low 60s. Large scale
warm advection across the central portion of the country will setup
significant warming next week. The afternoon run of the NBM kicked
out highs in the low to mid 70s across much of the area next
Saturday and Sunday! The return of precipitation chances are looming
at the end of the extended period, but a large spread remains
across the global ensemble suite.
&&
.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 627 PM CDT Sun Apr 7 2024
Surface low currently near Yankton will pass through MKT around
8z and the Twin Cities around 12z on its way to Duluth Monday
afternoon. Ahead of this lows warm front, we`re seeing another
band of showers develop across northern IA/southern MN that will
pivot north across the area this evening, following the low. To
the east of the low and south of the warm front, skies are
actually VFR at the moment in IA and there`s potential we could
see a brief window of VFR cigs at MKT/MSP/RNH/EAU as the
low/warm front lift north of these locations, though any VFR
cigs will quickly fill in with MVFR/IFR cigs as cold air
advection to the south of the low will create steep low level
lapse rates and a stratocu field that quickly fills in. For
precip, much drier conditions are expected to develop as a
location moves to the south side of the low/warm front, with
those steep lapse rates potentially leading to convective shower
development Monday afternoon over southwest MN. If anything,
we`re likely too pessimistic with cigs once a location gets
south of the low/warm front (this is associated with a switch to
a WSW wind), but we have lots of time to fine-tune the forecast
for Monday afternoon.
KMSP...Enough uncertainty exists with the track of the low that
there`s somewhat low confidence in the forecast between about
10z and 14z, which is when the low will pass through the metro.
A farther west track of the low may allow for much of this
period to see VFR cigs. A low tracking farther east (over MSP),
would likely keep the airport socked in LIFR/IFR cigs with DZ
reducing vsbys as well. We have a dry TAF after the warm front
passes, though we may see some convective showers Monday
afternoon/evening.
/OUTLOOK FOR KMSP/
TUE...MVFR cigs, chc -SHRA in mrng. VFR aftn. Wind W 10G20 kts.
WED...VFR. Wind W 5-10 kts.
THU...Chc MVFR/-SHRA. Wind NW 15G25 kts.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...None.
WI...None.
&&
$$
DISCUSSION...Strus
AVIATION...MPG
Area Forecast Discussion
National Weather Service Norman OK
1039 PM CDT Sun Apr 7 2024
...New AVIATION...
.SHORT TERM...
(This evening through Monday)
Issued at 221 PM CDT Sun Apr 7 2024
An extremely dry airmass remains in place across our area today as
we are in the dry sector of a powerful occluded low across the
central Plains. Winds will continue to slacken this evening and
overnight as the pressure gradient continues to collapse, though the
westerly direction of the surface wind will remain relatively
consistent. The one exception is across far northern Oklahoma, where
a cool front will try to push in from Kansas before it gets absorbed
by the background flow. With weaker winds and no moisture, lows
tonight will range from close to 50 in the southeast part of our
area to the mid-30s in the northwest portion.
The risk for severe weather returns tomorrow and appears to be over
a broader zone than was apparent in previous forecasts. There is
still some question about northward moisture return within the STJ-
dominated environment; the HRRR would bring the leading edge of
modified Gulf air to a line running from east of Lubbock to OKC to
Tulsa by 5:00 pm tomorrow, while the NAM would suppress that airmass
from Lubbock to about Texarkana. This will be important to monitor
since the first wave of convection initiation appears probable along
the triple point in western Texas late in the afternoon. This
activity will most likely track into our western north Texas and
potentially southwestern Oklahoma counties in the evening. The
initial threat with this activity will be large to very large hail
with relatively weak low-level shear and 80 knots of LCL-EL shear.
As storms continue eastward along the Red River, continued low-level
theta-E advection will offset the loss of diurnal heating to
maintain an environment with 1,500 J/kg of MLCAPE. Storms may tend
to grow upscale into an MCS over time with the primary hazard
transitioning from large hail to damaging winds.
As for you eclipse-watchers - things still look pretty decent. Some
of the more reliable cloud-modeling guidance (the RDPS and NAM
especially) are showing a very low chance from widespread stratus or
cumulus cloud cover across our southeast Oklahoma counties, with
high chances of no cloud cover up to 30,000 feet. Forecast soundings
do suggest a near-saturated layer close to the tropopause, which
conceptually fits with expected cirrus at the lead edge of the STJ.
However, conditions continue to look moderately favorable for at
least some eclipse viewability.
Meister
&&
.LONG TERM...
(Monday night through next Saturday)
Issued at 221 PM CDT Sun Apr 7 2024
The risk for severe weather will persist from tomorrow evening into
tomorrow night as the initial wave of storms continues eastward
across the forecast area. With the warm front continuing to lift
north and isentropic ascent begins to overspread the west Texas
plains, another round of storms seems like it will initiate sometime
late in the overnight period or perhaps early Tuesday morning to the
west of our area. This will give more chances for storms across
western north Texas in particular, with some risk for flooding by
Tuesday morning.
A severe risk will continue during the day on Tuesday, as the
surface low translates east and a little south from West Texas
toward the Big Country. In general, convective-allowing guidance
keeps the warm sector further south than global guidance as a
response to multiple rounds of convection. However, embedded
thunderstorm activity in western north Texas and southern Oklahoma
will have the potential to produce large hail at times. The greater
risk may end up being the potential for excessive rainfall,
especially with multiple rounds of storms expected through Tuesday
evening.
The upper low to our west that is responsible for this activity will
finally make its way into central Texas on Wednesday. Northerly
winds will continue at the surface, but saturated profiles within
southern Oklahoma will most likely lead to another day of showers
and embedded thunderstorms. Things finally will begin to dry out
Wednesday evening as some drier air pushes in from the north. This
will set the stage for some drier and slightly cooler days on
Thursday and Friday.
Meister
&&
.AVIATION...
(06Z TAFS)
Issued at 1036 PM CDT Sun Apr 7 2024
Light winds will continue overnight with a few locations in
northern and western OK shifting to the NE. Winds will be variable
Monday but eventually shift shift towards the N and NE where they
will stay as sfc low and boundary moves across the area. Storms
will be possible late Monday afternoon and evening with highest
chances in S Ok and western north TX. VFR ceilings are expected
most of the TAF period but MVFR ceilings will be possible Monday
evening, especially with the storms.
&&
.PRELIMINARY POINT TEMPS/POPS...
Oklahoma City OK 45 78 54 67 / 0 20 80 60
Hobart OK 42 78 51 66 / 0 30 70 70
Wichita Falls TX 47 83 56 69 / 0 30 90 90
Gage OK 37 70 42 68 / 0 0 30 30
Ponca City OK 43 74 50 71 / 0 0 50 20
Durant OK 48 83 60 69 / 0 20 90 90
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...None.
TX...None.
&&
$$
SHORT TERM...04
LONG TERM....04
AVIATION...25