Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 05/20/24
Area Forecast Discussion
National Weather Service Bismarck ND
1037 PM CDT Sun May 19 2024
.KEY MESSAGES...
-Lows tonight in the far west are forecast in the mid-30s.
- Expect below normal temperatures with daily chances for rain
this coming week through the upcoming holiday weekend.
&&
.UPDATE...
Issued at 1030 PM CDT Sun May 19 2024
All severe storms are done. The Severe Thunderstorm Watch was
cancelled at 03z, however a strong storm remains in northern
Stutsman County. Small hail is possible with that as it moves
north.
Lows tonight are forecast to dip down into the mid-30s in the
far west. Frost should not be a concern.
UPDATE
Issued at 716 PM CDT Sun May 19 2024
A Severe Thunderstorm Watch has been issued in the south central
until 04z. The current storm is moving north into southern
Morton County more may move into Emmons later.
UPDATE
Issued at 646 PM CDT Sun May 19 2024
Storms have fired in the southwest and south central. The
strongest in the one entering Sioux County where 3000 J/kg of
MUCAPE, 400 ms/s2 of effective helicity, and 70 kts of effective
shear and 1000 J/kg of MLCAPE. The straight upper levels of the
hodographs support splitting storms. This storm may or may
already be in the process of splitting, and we would be dealing
with the left mover, producing hail. The severe threat should
only last until sunset, mainly in the south central.
&&
.DISCUSSION...
Issued at 340 PM CDT Sun May 19 2024
Western and central North Dakota currently sits under southwest
flow aloft as a broad western US trough approaches. A surface
low is currently located over eastern Wyoming and should move
into western South Dakota by late afternoon and early evening.
Precipitation chances will increase during this time frame from
south to north along an inverted surface trough to the north of
the low and an east to west oriented warm front near or just
south of the South Dakota border. The highest rain chances will
be across the south central and into portions of the James River
Valley (60 to 90 percent) with low to medium chances further
north and west (30 to 60 percent).
As far as the severe weather potential goes, it does seem
reasonable that we could see a fairly brief window for a strong
to severe storm or two across southern portions of western and
central North Dakota. However, the best chance for a severe
storm or two is likely to be over the far south central, mainly
over Sioux and Emmons counties. Confidence has decreased a bit
regarding the severe weather potential as clouds have been
stubborn to clear out in the most favored area for initiation
per the latest CAMs. Thus far, the clouds have kept any
appreciable instability south of the area with MUCAPE values
only approaching 500 J/kg or so south of the I-94 corridor.
MLCAPE values only max out in the 100 to 250 J/kg range across
the south. That being said, RAP forecast soundings and SPC
mesoanalysis trends suggest that we could see a small area of
MLCAPE across portions of the far southwest and south central by
22z to 01z. Given the abundant cloud cover, this could be
overdone a bit. One aspect that will not be lacking is shear
with widespread effective shear forecast to be in the 50 to 65
knot range. This enhanced shear can also be gleaned from the
widespread billow clouds on visible satellite imagery across
south central North Dakota and north central South Dakota. Thus,
if the warm front can lift north far enough and clear the far
south central out it may not take a ton of instability for a
strong to severe storm to pop. A quick glance at the latest CAMs
suggests rapid convective initiation sometime in the 23z to 00z
hour. The strongest updraft helicity tracks are generally
confined to around the North Dakota/South Dakota border.
Instability should wane rather quickly after 01z and
thunderstorms will likely be in the weakening phase as they move
into the James River Valley. A few storms could remain strong
until around 03z before they move off into the Grand Forks
forecast area. In a worst case scenario, storms across the far
south central could see a brief window to produce damaging winds
to 70 mph, hail to the size of ping pong balls, and a
conditional risk for a brief tornado or two. Further north and
west, isolated to scattered showers with a few embedded rumbles
of thunder will be possible.
Some showers may linger across the north late tonight into
Monday morning as the shortwave moves off to the northeast. We
will stay in southwest flow aloft through at least Tuesday as
waves continue to rotate around the slow moving broad trough.
The flow then flattens out and becomes nearly zonal midweek
before the next potent trough approaches. Ensembles and global
models continue to struggle with the evolution of the late week
pattern regarding timing and track of this system. Either way,
rain chances appear medium to high (40 to 70 percent) for most
of western and central North Dakota Thursday into Friday. What
is up in the air still is where the heaviest precipitation will
fall and thunderstorm potential. Thus far, NBM is painting a
picture of low to medium chances for thunderstorms (20 to 40
percent) during this same time frame. CIPS analogs still suggest
some chances for severe weather towards the end of the week and
into the holiday weekend but CSU Machine Learning guidance does
not.
Lows tonight may become fairly chilly across the southwest
dipping into the mid to upper 30s. For now, frost is not
expected but it will be something to watch. Lows will be in the
40s elsewhere. Highs will be in the 60s Monday through Wednesday
and then we could see some 50s across the north on Thursday.
Friday could be the coolest day of the week with NBM forecast
highs in the lower 50s to lower 60s but the spread is rather
large, likely due to model/ensemble uncertainty regarding the
pattern. A warmup will then be possible over the holiday
weekend.
&&
.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 646 PM CDT Sun May 19 2024
VFR ceilings with scattered showers and thunderstorms. Winds
could be breezy in the showers and will continue for the next
few hours in the east. Monday morning ceilings look to lower
below 1000kft in KJMS for a few hours, otherwise skies clearing
in the west and scattered elsewhere.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE...Smith
DISCUSSION...ZH
AVIATION...Smith
Area Forecast Discussion
National Weather Service Dodge City KS
1041 PM CDT Sun May 19 2024
...Updated Aviation...
.KEY MESSAGES...
- Widespread low stratus clouds are expected Monday morning.
- Strong thunderstorms are possible along I-70 Monday evening.
- Cooler temperatures mid week.
&&
.SHORT TERM /THROUGH MONDAY/...
Issued at 1214 PM CDT Sun May 19 2024
17Z obs and upper air analysis shows widespread low 60 dewpoints
along and ahead of the dryline which is located in the far
western Oklahoma panhandle. A cu field is starting to show up on
satellite near Clayton, NM which will be monitored over the next
couple of hours for storm initiation. CAMs have been consistent
with storms forming and intensifying just west of the CO-KS
border around 2 pm and quickly expanding and growing linear as
they move eastward. HRRR wind gusts have been showing 60-80 kt
wind potential at 10m starting near the K-25 corridor and
growing eastward through the late afternoon and evening for the
rest of southwest Kansas. Storm warnings will most likely
reflect this with WEA activation for 80+ mph destructive wind
threat. Another threat that will be monitored as the squall line
matures east of highway 83 is QLCS tornadoes. 0-3 km bulk shear
values are already SW at 35 kts east of highway 281 and are
expected to increase with the intensification of the low level
jet after 00Z. QLCS tornadoes will be very hard to have lead
time on warnings as they are usually quick spin ups and along
with the already destructive straight line wind threat
regardless if the winds are rotating or straight they will be
over 80 mph. The squall line should be out of DDC CWA by 03Z.
Lower confidence of a rogue supercell this evening is still in
play mainly in NW Oklahoma around Woodward however this could be
as far north as Coldwater-Medicine Lodge. If this happens with
the low level jet, the moisture, and instability...this
particular feature could have giant hail and supercell tornado
potential.
Monday most of the day will be the atmosphere recharging as we
should have a weak frontal boundary and southeast winds bringing
in the return of some moisture. By the late afternoon and
evening a shortwave trough is forecast to develop in northwest
to north central Kansas and we could see another round of some
strong to severe storms capable of hail and gusty winds.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
Issued at 137 PM CDT Sun May 19 2024
Short long term discussion due to upcoming severe weather event
today. Main feature in the medium term model ensembles is a
large longwave trough over the western CONUS which will bring a
stronger cold front across Kansas Tuesday afternoon into
Wednesday. Most of the moisture and instability ahead of the
front will be in central Kansas and thus the severe weather
potential in southwest Kansas looks low. The longwave trough
hangs on in the central and northern plains through the late
workweek and with the upper level lows more in the northern
plains the storm threat will be mostly due to frontal passages
in northwest and north central Kansas Friday into Saturday.
&&
.AVIATION /06Z TAFS THROUGH 06Z TUESDAY/...
Issued at 1041 PM CDT Sun May 19 2024
Thunderstorms have ended across SW KS as of 0330z Mon. Strong
consensus of short term models is for IFR stratus to spread
rapidly to all airports through 12z Mon, in response to a strong
moisture return on light moist easterly upslope flow. Some
reduced visibility in BR/FG is possible, but the high confidence
is with the stratus. After 15z Mon, stratus is expected to
dissolve from south to north, with VFR returning to all
airports. Light winds will trend light SEly through 00z Tue.
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SHORT TERM...Tatro
LONG TERM...Tatro
AVIATION...Turner
Area Forecast Discussion
National Weather Service Hastings NE
711 PM CDT Sun May 19 2024
.KEY MESSAGES...
- Thunderstorms largely evade south central Nebraska and north
central Kansas this evening and overnight, though a brief
flare up isolated strong storms can`t be ruled out late S of
the state line.
- Another round of storms (some severe) is expected on Monday
afternoon through Monday night, though details on
timing/coverage remain somewhat uncertain. The trend has been
for activity to arrive/develop later (near or after sunset).
- Storm chances linger into Tuesday, with conditions trending
drier Tuesday evening through Wednesday.
&&
.UPDATE...
Issued at 710 PM CDT Sun May 19 2024
Will be working on an update shortly to lower shower and tstm
chances further for the rest of the evening and overnight as it
appears the bulk of activity will remain mostly W and S of the
forecast area. Hopefully we`ll be able to coordinate a watch
cancellation soon, as well...though the low confidence of what
exactly will happen with the convection in NW KS may dictate
otherwise. Bottom line, though, even if the low end chance for
additional tstms indeed pans out, this would likely be limited
to far SW-S zones, and be marginally severe, at best. This is
due to persistent cloud cover that has done well to reduce
destabilization potential and keep temps considerably cooler
than once forecast. Furthermore, latest model guidance suggests
the bulk of convergence and WAA on nose of developing LLJ will
be "blocked" by the ongoing MCS over central KS. Perhaps some
isolated tstms flare up S of the state line late overnight as
the LLJ veers, but severe weather would be unlikely.
&&
.DISCUSSION...
Issued at 330 PM CDT Sun May 19 2024
Today has been a tricky forecast. As hinted by some of the
near-term models, an isolated supercell has developed in
northern Kansas. This has turned eastward and is JUST south of
our forecast area in Russell County as of 330pm. This storm will
be capable of all severe hazards (tornado, wind, very large
hail) as it slowly meanders eastward over the next few hours.
In addition to this, convection contuse to develop in southwest
Kansas and eastern Colorado. High-resolution models show this
activity continuing to develop into one or more west-east
propagating squall lines capable of dangerously strong winds
(75+ MPH). That said, the WoFS (Warn on Forecast System) has
been keeping the bulk of this activity south of our area
entirely.
Additional convection over the Nebraska panhandle could push
into central Nebraska later this evening, but should be on an
overall weakening trend. In fact, some of the latest HRRR runs
have this activity completely dissipating before it reaches us.
Monday will bring another risk for severe storms to the area.
There is still plenty uncertainty on exact details regarding
coverage and exact location, but it appears that the timing will
favor the later side, with some models (notably the NAMnest)
bringing us little to no convection until after midnight. Strong
deep-layer shear (40-50kt) will allow for a continued severe
threat with any storms that develop into the early morning hours
of Tuesday.
A few thunderstorms could redevelop Tuesday morning and early
afternoon as a cold front moves through the area. Gusty
northwest winds will arrive behind this front, and drier
conditions are also expected to return Tuesday evening through
Wednesday.
The upper pattern remains fairly busy through next weekend, with
continued chances for rain and thunderstorms. Above-normal
precipitation continues to be favored through the Memorial Day
weekend before possibly turning a bit drier as we head into
June.
&&
.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 655 PM CDT Sun May 19 2024
LOW confidence TAF cycle given uncertainties with CIGs and VSBYs
due to convection in the region.
Have removed any mention of VCSH or VCTS as it appears any
activity will remain pretty far W/S of the area tonight. While
that is one aspect of the forecast that have come into some
clarity, the late overnight trends for stratus and/or fog have
not. In general, models have been trending towards more stratus
and perhaps even some light fog - neither of which seem
unplausible given a period of lgt (and somewhat variable) low
level flow ahead of a front, and recent rainfall both locally
and upstream to the S. Didn`t feel comfortable carrying a VFR
TAF all night, so leaned towards the IFR stratus as being more
likely than IFR/MVFR VSBY`s, but will have to closely monitor
trends for potential amendments. Appears stratus could linger
into at least mid to late AM as CIGs rise to MVFR, then scatter
out some for the aftn.
Winds will generally remain out of the S this eve, then bec lgt
and vrbl for a time before veering to the SW/W after 06Z, then
NW towards dawn behind a weak front. N-NNE winds around 7-11kt
look to prevail late AM thru the aftn. Confidence on wind is
medium.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...None.
KS...None.
&&
$$
UPDATE...Thies
DISCUSSION...Mangels
AVIATION...Thies
Area Forecast Discussion...Updated
National Weather Service Lincoln IL
943 PM CDT Sun May 19 2024
.KEY MESSAGES...
- Temperatures remain above normal through Tuesday, with highs in
the upper 80s or low 90s. Peak heat indices will be in the low
90s each day.
- Scattered thunderstorms, mainly north of I-72 (20-30% chance),
through this evening. Severe weather is unlikely but funnel
clouds or a brief landspout can`t be ruled out. Slow storm
motions could lead to locally heavy rainfall exceeding 1.5".
- Severe thunderstorms are possible Monday through Wednesday,
although the areas at risk vary each day. The greatest risk is
the potential for damaging winds northwest of the IL River late
Tuesday evening, as well as south of I-70 on Wednesday
afternoon.
&&
.UPDATE...
Issued at 943 PM CDT Sun May 19 2024
Scattered convection has finally subsided over most of the area.
One shower is developing in northeast Tazewell Co, likely on an
outflow boundary from an earlier storm. Not expecting it to get
out of hand (famous last words) but going to extend the 20 pops to
account for it and any other possible showers that might develop
this evening. Remainder of forecast looks fine, but update will be
coming shortly.
Auten
&&
.SHORT TERM... (Through Late Monday Afternoon)
Issued at 234 PM CDT Sun May 19 2024
As of 2pm/19z, the diffuse frontal boundary that`s been draped
across the area today does seem to have lifted back to the north,
with NE winds at Pontiac and Peoria, but a southerly component to
the wind at Lincoln/Bloomington/Champaign. To this point, Cu
development had been fairly limited, but day-cloud phase satellite
imagery shows sporadic signs of glaciation occurring in Vermilion
and Menard County. We`ll likely see increasing vertical
development eventually leading to deep convective initiation over
the next few hours, which is consistent with what the CAMs have
shown. The latest RAP mesoanalysis is still showing a corridor
near that frontal boundary where non-supercell tornado parameter
values range from 0.5 to 1, so a funnel or isolated landspout
could occur as cells deepen this afternoon. With weak shear,
storms should be relatively short- lived, but they also won`t be
moving fast and if an updraft manages to persist longer than
expected locally heavy rainfall could occur (isolated totals over
1.5" possible). These storms should wane after sunset.
A shortwave is progged to lift NE from the Plains towards the
upper Midwest early Mon AM, which could produce a few
showers/storms NW of the IL River before midday. The forecast gets
a little more complicated into the afternoon. Zooming out and
stepping back for a moment, explosive thunderstorm development is
expected over KS this evening. This matters for us because CAMs
depict a remnant MCV lifting NE thru IA toward N IL, which could
provide additional forcing for storms Mon PM, even though the
primary upper wave will be positioned well north of the area by
that time. The environment does look marginally supportive of
severe weather, with moderate instability and weak shear (less
than 30 knots). Forecast soundings show an inverted-V profile
below the cloud deck, with over 1000 J/kg of DCAPE. The weak shear
means storms will likely lack organization, but that thermo
profile could support sporadic hail or strong wind gusts. As is
often the case with MCVs, there is still a good deal of
uncertainty as to where it ultimately tracks, how expansive the
associated cirrus shield will be, and what impacts that
subsequently has on the destabilization. For now, most of the CWA
north of I-70 is in a marginal risk (level 1 of 5) for severe
weather, but far northern portions of the CWA (Marshall and
northern Woodford/McLean Counties) are in a slight risk (level 2
of 5).
Erwin
.LONG TERM... (Monday Night through Next Sunday)
Issued at 234 PM CDT Sun May 19 2024
Severe t-storm potential exists across portions of the ILX CWA
both Tues evening (level 3 of 5 risk west of IL River) and Wed
(best chance south of I-70), driven by a volatile environment
ahead of an advancing cold front. Unfortunately, we`re at a time
of year where the mesoscale details become quite murky more than
24 hours in advance, owing to multiple rounds of convection
progressing across the Plains and Midwest between now and
Wednesday.
The current expectation is that an emerging upper level trough
will result in a deepening sfc low across the west-central Plains
by late Mon, which eventually lifts northeast to the upper
Midwest on Tues. WAA could result in a few elevated (not surface-
based) storms Mon night into early Tues AM. Forecast soundings
don`t look particularly impressive, but there could be a low-end
hail threat from these storms. For Tues afternoon, forecast
soundings show strong capping across the entire ILX CWA, owing to
a +18 to +20 degC warm nose. Storms are expected to form along a
cold front across IA Tues afternoon and eventually progress SE
into the CWA, but they likely won`t move in until after 7pm
Tues/00z Wed. Given the expected storm mode (linear or quasi-
linear), damaging winds remains the top concern, but all hazards
are possible. Forecast hodographs do become elongated in the low-
level as the LLJ kicks in, with nearly 50 knot winds just 1km AGL
Tues eve, resulting in roughly 30 knots of 0-1km shear and around
200 J/kg of 0-1 SRH. 0-3 km shear values are around 40 knots,
which gives some wiggle room for embedded surges within the line
to hit 30 knots of line-normal 0-3 km shear. All of those
aforementioned low-level shear/helicity values suggest a tornado
threat will exist in addition to the damaging wind potential.
Exactly how long, and how far east, these threats persist into the
night remains uncertain, and this is well reflected in the Day 3
convective outlook which gradually lowers the risk category with
eastward extent.
Wednesday`s severe threat will still ultimately depend on where
the front/outflow from Tuesday night`s storms set up. Some
guidance has been trending slower/further north with the frontal
placement, so while the most likely area for severe weather is
still south of I- 70, the I-72 corridor could wind up being at
risk as well. Between the mesoscale uncertainty and the northward
trends, was not as comfortable reducing the northwestward extent
of PoPs compared to previous forecast cycles. Ahead of the front,
the environment is expected to remain quite volatile with ample
instability (approaching 2500 J/kg). Despite the primary upper
wave associated with Tuesday`s storms lifting well off to the
north, a secondary short wave will place a new strong mid-level
jet streak over the region (60+ knot flow at 500mb), resulting in
40-50 knots of deep layer shear across the warm sector. Shear
profiles continue to look rather unidirectional, and deep layer
shear vectors parallel to the front suggest a linear storm mode
with damaging winds as the primary threats, while hail is also a
concern.
Temperatures cool off a bit behind the front, with highs in the
upper 70s/low 80s for the end of the work week. The upper wave
pattern remains quite progressive into next weekend, so the
extended forecast continues to be littered with precip chances -
but model spread in the timing and placement of any specific
disturbance is quite large. The CPC 6-10 day precip outlook (May
25-29) shows a 40- 50% chance of above normal precip.
Erwin
&&
.AVIATION... (For the 00z TAFs through 00z Monday Evening)
Issued at 759 PM CDT Sun May 19 2024
Most sites will be VFR this evening, through the night and into
tomorrow. However, isolated storms keep percolating around CMI
and DEC this evening. Vis and cigs will be an issue with the
storms, either on station at DEC or in the vicinity at CMI. PIA
could see something over night hour, but looks like the showers
will remain southeast of there, so not adding. Cirrus is expected
overnight and tomorrow, but additional convection is possible
tomorrow afternoon at all sites. Will not add VCTS at this time,
but will have broken cigs around 5kft at each site to indicate
possible showers or storms. Winds will be light and variable
through the night but become southwest tomorrow with gusts up to
20-22kts possible at each site.
Auten
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Area Forecast Discussion
National Weather Service Indianapolis IN
917 PM EDT Sun May 19 2024
.KEY MESSAGES...
- Isolated showers and storms across parts of the northern forecast
area this afternoon and Monday afternoon/evening.
- Unseasonably warm through Tuesday, highs in the mid to upper 80s.
- Increasing threat for at least 1-2 rounds of strong/severe t-
storms late Tuesday through Wednesday.
- Pattern remains active going into the weekend with storm chances
Friday night through Sunday.
&&
.FORECAST UPDATE...
Issued at 917 PM EDT Sun May 19 2024
- Thunderstorms ending far northwest; Otherwise Mostly clear and
warm.
- Lows in the low to mid 60s; Warm
Surface analysis late this evening shows a broad yet poorly
organized area of high pressure stretching from NY State, across
Indiana and Ohio and then to points southwest including LA and
Mississippi. The remnants of a weak cold front was still found over
far northwest Central Indiana. This front along with what is left of
diurnal heating was still allowing some thunderstorms to be present
over the Kokomo and Delphi areas. Weak southerly surface flow
remained in place across Central Indiana and dew point temps were in
the lower 60s.
As heating continues to be lost over the next few hours any
lingering convection in the northern parts of the forecast area is
expected to diminish and end. This should lead to dry weather across
the entire forecast area by 11pm-12a. HRRR is on board with this,
showing our forecast area precipitation free by midnight. Forecast
soundings overnight continue to show a dry column overnight and dew
point depressions are suggested to remain at 3F or greater. Thus the
fog threat overnight does not appear to be as great as the previous
nights. However, a caveat tonight will be area across the northwest
part of our forecast area that have just received new rainfall.
Additional lower level moisture in these are may all for the
development of fog with lower dew point depressions that might be
suggested. Thus will include at least a patchy fog mention at those
locations. Overall ,with light to calm southerly winds in place
across the area lows in the lower to mid 60s appear reasonable.
&&
.SHORT TERM (This evening through Monday)...
Issued at 256 PM EDT Sun May 19 2024
Weak ridging within a broad split flow pattern will promote rather
benign weather through the period. Our one exception may be a few
isolated showers or storms this evening near our northern CWA border
where a weak boundary resides. There is little in the way of flow
through the depth of the column. As such, storm-scale organization
beyond single/pulse cell is not expected. Nevertheless, the column
is quite dry so a core collapse leading to a brief burst of gusty
winds and small hail is not out of the question. Overall the threat
appears very low (under 25 percent).
Any convection is expected to diminish as night falls, leaving us
with a few lingering mid to high-level clouds. Winds at the surface
may go light and variable as the boundary layer decouples. As
mentioned before, the column is quite dry...so any fog overnight
will likely be very patchy in nature and mainly ground fog. With dew
points in the low 60s and no advection our low temperatures likely
remain in the 60s as well.
Monday will be quite similar to today, including a low risk for
showers and storms in our far north/northwest. Shower and storm
chances are again diurnally driven within a low-flow atmosphere.
Anything that develops will likely go through its life cycle within
an hour. The thermodynamic profile also remains similar to today, so
a low risk of a brief downburst (gusty winds and small hail) exists
in our northwestern counties.
As for temperatures, there is little to no change at the 850mb
level. However, displacement of the ridge to slightly east of us may
allow for a more brisk SSW wind (10kt) to develop during the
afternoon Monday. This may in turn lead to deeper mixing than today
allowing temperatures to be a degree or two higher.
&&
.LONG TERM (Monday night through Sunday)...
Issued at 256 PM EDT Sun May 19 2024
Monday Night Through Wednesday.
Another mild night is expected Monday night with lows only falling
into the mid to upper 60s as southerly flow keeps dewpoints above
normal for this time of the year. Winds will be weakest across the
southern counties so will have to keep an eye out for fog as those
areas are also where we expect the sparsest cloud cover, but with a
few days of drying out fog will likely be limited to the river
valleys. Focus then quickly shifts to the potential for strong to
severe storms as a strong upper level low pressure system moves from
the Dakotas into the Upper Midwest and a surface cold front
stretches down into the Ohio Valley.
Storm chances begin as early as late Tuesday night as the surface
cold front pushes into northwestern Illinois and a weakening MCS
looks to potentially push out ahead and impact western Indiana.
There remains a fair amount of uncertainty as to if the MCS can
survive that late into the night with a lack of robust instability,
but if the cold pool matures it may last longer than the models
suggest. Location of where this could impact is very uncertain but
a best guess right now would be along the I-70 corridor.
The better severe weather threat looks to set up Wednesday evening
into the early overnight hours along and just ahead of the frontal
passage. With dewpoints near 70, surface based CAPE values may be
well into the 2500-3500 J/kg range with models showing robust
moisture transfer in the 850-700mb layer. Shear is a bit more
marginal with the 500mb jet more towards western Illinois keeping
the effective bulk shear more towards 30kts which would still be
more than enough for severe weather, but may limit the higher end
threat. Surface winds will also be generally southwesterly which
will limit the curve in the hodograph. Another factor working
against the overall severe threat is a weak cap at the top of the
boundary layer, but lift right along the front should be enough to
overcome the cap but would mean that the convection would generally
be limited to just along and not ahead of the front.
With all that in mind, do think that there is a solid shot for
isolated to scattered severe weather Wednesday evening into the
early overnight, especially across the southern half of the state
with a storm complex along the surface cold front. With several
unfavorable factors there is a potential for the lower end severe
threat, but lift with the front will help to overcome some of the
more limiting of the factors.
Thursday Through Sunday.
The surface front is then expected to stall just south of the Ohio
River Thursday into Friday with additional storm chances south of
the forecast area. Confidence that the front settles to the south
is fairly high so will limit the afternoon POPs compared to previous
forecasts. By Friday afternoon there is a small chance that the
front pushes just far north to impact the southern counties, but by
then the front will be fairly diffuse and less impactful overall.
There does look to be a weak wave that may generate another storm
complex, but again that is currently expected to be more of an issue
along and south of the Ohio River.
Confidence in the forecast going into the weekend is fairly low with
significant model spread on the broader synoptic scale, but the
pattern looks to remain active with at least one round of storms
likely between Friday night and Sunday.
&&
.AVIATION (00Z TAF Issuance)...
Issued at 659 PM EDT Sun May 19 2024
Impacts:
- Thunderstorms near LAF dissipate quickly this evening; Otherwise
VFR
Discussion:
VFR conditions expected through the TAF period. Thunderstorms have
developed along a stalled frontal boundary just north of LAF. HRRR
suggests these storms will dissipate as diurnal heating lost.
After the heating is lost, our weather will be dominated by a large
area of high pressure stretching from NY State, across Indiana to
the southern Mississippi Valley. Forecast soundings show a dry
column tonight. Dew point depressions tonight are expected to be
greater than 3F. Thus fog will not be as much of a concern overnight.
Forecast soundings on Monday show a dry column with unreachable
convective temperatures as a bit warmer and drier air aloft arrives
in the area. Thus will result in continued VFR and only some passing
CI.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE...Puma
SHORT TERM...Eckhoff
LONG TERM...White
AVIATION...Puma
Area Forecast Discussion
National Weather Service San Francisco CA
602 PM PDT Sun May 19 2024
...New AVIATION, MARINE...
.SYNOPSIS...
Issued at 1237 PM PDT Sun May 19 2024
Typical summer-like pattern to persist throughout the first half of
the week. Temperatures are forecast to dip below seasonal averages
by late week and into the upcoming weekend as an upper level trough
impacts the region.
&&
.SHORT TERM...
(This evening through Monday)
Issued at 1237 PM PDT Sun May 19 2024
Clouds continue to rapidly erode as of early this afternoon and will
continue to do so into the evening. Low clouds are more than likely
to return to the Monterey Bay region and the San Francisco Peninsula
overnight but will clear by early-to-mid morning. Also, cannot rule
out patchy drizzle in and around the Monterey Bay early Monday
morning.
Afternoon temperatures for Monday will be similar to today, yet
coastal areas will warm by a few degrees thanks to northerly flow
across the region. Thus, expecting highs to range from the lower
60`s to near 70 degrees at the coast with mid 70`s to lower 80`s
across the interior.
&&
.LONG TERM...
(Monday through Saturday)
Issued at 301 AM PDT Sun May 19 2024
A slight warming trend is expected through mid-week with
temperatures building into the upper 70s to mid 80s by
Tuesday/Wednesday. Inland stratus coverage is expected to be less
impressive this week as a deeper marine layer and gusty offshore
winds keep the atmosphere well mixed and low clouds confined to the
coast. Ensemble guidance agrees that Tuesday is looking to be the
warmest day this week with the highest probability of widespread
temperatures greater than 80 degrees. Minor heat risk begins to
spread through most of the Bay Area and portions of the Salinas
Valley Monday through Thursday. People who are incredibly sensitive
to heat should take precautions while outdoors and remember to drink
plenty of water.
By late week, upper level troughing strengthens and moves farther
south into California with an associated surface low passing through
the state. This will bring about a pattern change with widespread
below average temperatures expected. By the weekend, inland highs
will be in the upper 60s to mid 70s with coastal highs in the upper
50s to low 60s. CPC temperature outlooks have temperatures leaning
below average through the end of May and into the beginning of June.
Ensemble guidance suggests this system will be fairly dry for our
region with any precipitation associated with it directed northwards
of us into far northern California/southern Oregon.
&&
.AVIATION...
(00Z TAFS)
Issued at 602 PM PDT Sun May 19 2024
A weak and dry surface low pressure center over the northern
Central Valley is juxtaposed to an increasing pressure gradient
over the coastal and offshore waters. The ACV-SFO pressure
gradient is 6.7 mb and the SFO-SAC pressure gradient is 3.2 mb.
It`s VFR, however regionally it`s a complex surface pressure
pattern (winds) coupled to an evolving dynamic pattern involving
upper level troughing. The marine layer depth to the base of the
low level temperature inversion varies along the coast and will
vary greatly tonight and Monday morning with offshore winds
(downsloping, warming) over the North Bay to SF Peninsula while
locally onshore winds (upsloping, cooling - sufficient cooling to
erode the marine layer temperature inversion) over the South Bay
to the north Central Coast.
In the near term the HRRR output appears to have a better handle
(vs the NAM) on near surface humidity, it helps determine cigs vs
no cigs forecast. Monitoring the aforementioned surface low in
the Central Valley and its southward motion tonight and Monday,
the low will influence surface winds. For example surface winds at
KSJC are likely to shift over to southeasterly 5 knots increasing
to 8 to 10 knots 09z-17z Monday.
Vicinity of SFO...Peak wind gust to 37 knots 2355z prompted an
airport weather warning for gusty west winds until 04z (9 pm PDT)
this evening, more recent 5 min obs show the wind has subsided a
little bit. Strong NW winds over the northern coastal waters are
sweeping evaporated sea salt to the air resulting in hazy/haze
conditions, limiting surface visibilities to 5 miles /MVFR/ along
the coast. West wind at KSFO is periodically transporting haze
from the coast to the terminal. Otherwise VFR/MVFR tonight and
Monday, west wind easing overnight to less than 10 knots. West
wind increasing Monday afternoon and evening to 18 gusts 25 knots.
SFO Bridge Approach...Similar to SFO.
Monterey Bay Terminals...Onshore winds 10 to 20 knots early, easing
overnight to 5 to 10 knots. It`s a complex forecast regarding cigs
tonight and Monday as described above this area will begin losing
its marine layer temperature inversion allowing for good vertical
mixing with drier air aloft, however upsloping, cooling may still
produce a sct-bkn cloud cover /MVFR/ best chances late tonight and
Monday morning. Cyclonic circulation/eddy circulation over the
Monterey Bay Monday morning may temporarily improve ceiling
development around sunrise, unless downsloping, warming, drying
across the Monterey Bay (from the Santa Cruz Mountains) is enough
to offset cloud development. Otherwise VFR Monday.
&&
.MARINE...
(Tonight through next Friday)
Issued at 450 PM PDT Sun May 19 2024
Buoy observations over the outer waters are beginning to show
wind gusts reaching gale force this afternoon. Strong northerly
winds and gale force gusts will be present over much of the waters
today and Monday, with only slight reductions in wind speed
during the overnight hours. Expect hazardous conditions and
steeper wind waves from these building winds throughout the next
work week. It is not until next weekend that winds are expected to
ease.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
CA...None.
PZ...Gale Warning until 3 AM PDT Monday for Pt Arena to Pt Reyes 0-10
nm.
Small Craft Advisory until 3 AM PDT Tuesday for Pt Reyes to
Pigeon Pt 0-10 nm.
Small Craft Advisory until 3 AM PDT Monday for Pt Pinos to Pt
Piedras Blancas 0-10 nm.
Gale Warning until 9 AM PDT Tuesday for Pt Arena to Pt Reyes 10-
60 NM.
Gale Warning until 3 AM PDT Tuesday for Pigeon Pt to Pt Pinos 10-
60 NM.
&&
$$
SHORT TERM...RGass
LONG TERM....Kennedy
AVIATION...Canepa
MARINE...AC
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Area Forecast Discussion
National Weather Service Raleigh NC
1006 PM EDT Sun May 19 2024
.SYNOPSIS...
High pressure will extend across and offshore the Middle Atlantic
through Tuesday.
&&
.NEAR TERM /THROUGH TONIGHT/...
As of 1000 PM Sunday...
Only minor tweaks were made to hourly temperatures and sky cover as
stratocumulus deck has persisted longer in the Coastal Plain while
widespread clearing has occurred across the Piedmont. Otherwise the
forecast remains on track for areas of fog develop across northern
portions of the Piedmont with patchy fog elsewhere.
As of 400 PM Sunday...
Water vapor imagery shows multiple embedded waves within an
elongated trough axis extending from off the Northeast coast through
the Mid-Atlantic with a compact shortwave at its base over the SC/GA
coast. One wave sliding through south-central VA will continue
southward and over central NC through this evening with some Hi-Res
guidance indicating a light sprinkle or two, but most locations will
remain dry as RAP point forecast soundings show multiple weak
inversions aloft and relatively dry thermodynamic profile.
Widespread afternoon cumulus is expected to dissipate with loss of
boundary layer mixing, minus pockets light rain/sprinkles and
associated cumulus clouds, will briefly lead to mostly clear skies
early overnight. Light northeasterly flow overnight will advect
marine layer stratus into the Coastal Plain towards daybreak. West
of this cloud deck, lingering rich boundary layer moisture and
mostly clear skies will favor the development for areas of fog,
potentially dense is some locations, from the Triangle towards the
Triad by daybreak Monday morning. Overnight lows will settle in the
mid 50s to low 60s.
&&
.SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
As of 152 PM Sunday...
High pressure ridging will be in place at mid-levels for our Monday.
High pressure at the surface off the east coast will continue to
nose down into the area, resulting in a NE flow once again. We will
see some stratocumulus develop for the daytime, but more sunshine is
expected as deeper mixing ensues, especially across the Coastal
Plain. The airmass will warm some too, but highs should still be
about a degree or so below seasonal norms in the upper 70s to low
80s, lowest in the NE Piedmont to northern Coastal Plain of perhaps
mid 70s. Clear skies and light winds in the evening and overnight
will favor lows a touch below average in the mid to upper 50s,
except low to mid 50s in the NE Piedmont and northern Coastal Plain.
Lingering low-level moisture could favor fog development from the
Triangle eastward into the Coastal Plain for early Tue morning.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
As of 350 PM Sunday...
Dry conditions and mostly sunny skies are expected across central NC
on Tuesday and Wednesday as mid/upper ridging extends from the
western Gulf of Mexico to off the Mid-Atlantic coast. This ridging
will be in between a series of shortwaves moving across the northern
Plains and Upper Great Lakes and a cutoff low off the Southeast US
coast. At the surface, elongated high pressure will extend from the
NE down the Eastern Seaboard, initially bringing NE flow that shifts
more southerly on Wednesday as the high shifts SE to near Bermuda.
This will help increase high temperatures from lower-80s on Tuesday
to mid-to-upper-80s on Wednesday and upper-80s to lower-90s on
Thursday. Lows will also increase from upper-50s to lower-60s on
Tuesday night to lower-60s to upper-60s by Thursday night.
The pattern turns more unsettled from late this week into the
weekend. As one shortwave moves across the northern Great Lakes and
northern New England on Thursday/Thursday night, it will drag a cold
front that approaches the Appalachians. However, with the best upper
forcing to our north, only carry slight to lower chance POPs
(highest north). A better chance for showers and storms comes on
Friday and Saturday as a southern stream wave moves across the TN
Valley and potentially over our region. Carry high chance POPs on
these days, but didn`t feel comfortable going likely considering
timing differences between the different models and given this is
Days 6-7. POPs decrease a bit again on Sunday as the shortwave
exits, but still above climo. Temperatures are more uncertain during
this period and will depend on how far south the aforementioned cold
front is able to get, but the latest GFS and ECMWF keep it mostly
hung up to our north. So forecast highs remain near to slightly
above normal.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
As of 720 PM Sunday...
A challenging aviation forecast, with lower confidence than usual.
Broken VFR stratocu persists from RDU to the E (RWI) and S (FAY),
streaming in from SE VA within light NE surface flow and beneath a
15-20 kt northeasterly low level jet nosing into the NC Coastal
Plain from the Delmarva at 2000-4000 ft AGL. Lower MVFR cigs are
found over coastal sections, while the NW Piedmont (INT/GSO) is
mostly clear but with some VFR clouds drifting in from SW VA. With
light surface winds within high pressure ridging nosing in from the
north, in tandem with a lack of higher clouds and a high near-ground
RH overnight, will foster good radiational cooling and perhaps
shallow fog bank development in areas that see few clouds or partial
clearing through this evening, however an extended mostly clear
period to allow for fog formation is less than certain, given the
persistent clouds in the E and upstream of the NW. The greatest
chance for sub-VFR conditions (likely MVFR cigs/vsbys) will be
across portions of the N Piedmont, but most likely to occur N and NW
of RDU and holding E of GSO/INT. The most likely scenario is a
thinning of the stratocu in the E (RDU/RWI/FAY), while scattered
clouds continue to move in near INT/GSO, then MVFR cigs should
develop after 07z at all sites, with MVFR vsbys in fog along with
isolated banks of shallow IFR fog. Cigs may briefly dip to IFR
around daybreak, but confidence in this is low. Conditions should
improve to VFR gradually between 13z and 15z, and persist through
the end of the TAF valid period. Dry weather will hold, with surface
winds generally light from the NE, but increasing to around 10 kts
at RDU/RWI/FAY after 14z Mon.
Looking beyond 00z Tue, a good chance for sub-VFR fog is expected
late Mon night through daybreak Tue. Otherwise, VFR conditions will
dominate through Thu, although the chance for showers and storms
will return for Thu and Fri, mainly each afternoon/evening. -GIH
Lows will bottom out in the mid/upper 50s to low 60s.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...MWS
NEAR TERM...Swiggett/Green
SHORT TERM...Kren
LONG TERM...Danco
AVIATION...Hartfield
Area Forecast Discussion...UPDATED
National Weather Service Springfield MO
735 PM CDT Sun May 19 2024
.KEY MESSAGES...
- High confidence in above average temperatures today into
early this week (mid to upper 80s).
- Chance for two rounds of showers and thunderstorms through
Monday. First is late tonight into early Monday morning along
and west of Highway 65 (20-50% chances). Second is Monday
afternoon/evening along and north of Highway 32/I-44 (15-30%
chances). Large hail and damaging winds possible with these
storms (5% chance).
- Slight (2 of 5) risk to Enhanced (3 of 5) risk for severe
weather Tuesday evening through Tuesday night. Damaging wind
gusts are the primary concern (15-30% chances) with large hail
(15% chance) and a few spin-up tornadoes (2-5% chances) being
a lower-end threat.
- Potential for another round of severe weather Wednesday toward
south-central Missouri (15% risk/confidence).
- Unsettled weather may persist through the end of this week and
into Memorial Day Weekend (daily 30-50% chances for showers
and thunderstorms).
&&
...MESOSCALE CONVECTIVE DISCUSSION...
Issued at 730 PM CDT Sun May 19 2024
An ongoing severe MCS with damaging wind gusts of 60-90 mph and
occasional large hail is located across central Kansas. This is
an area of 3000-4000 ML CAPE and 40-50kts 0-6km bulk shear ahead
of a upper level disturbance. Latest 00z KSGF sounding showed
much less instability and shear (~1200j/kg ML CAPE and 25kts
0-6km shear) along with 100j/kg of ML CIN.
Latest Warn On Forecasts (WOFS) and HRRR guidance suggests a
high potential (< 90%) that the MCS will continue to be severe
as it moves into eastern Kansas. However once the MCS reaches
our southeast Kansas and western Missouri counties (after
10pm) it will begin to encounter higher ML CIN. Latest RAP
sounding for 12-1am is showing around 200j/kg of ML CIN which
will likely begin to decrease the severity of this line. That
being said, this MCS is developing a strong cold pool which may
allow the storms to continue slightly longer even into a more
hostile airmass. Therefore a Severe Thunderstorm Watch is in
effect until 2am for portions of southeast Kansas and western
Missouri. Damaging winds of 60-80mph is the most likely scenario
however given the steep mid level lapse rates and increasing
shear, a few instances of large hail may occur. Frequent cloud
to ground lightning is also expected.
The most severe portion of the MCS does look to slide just
northwest of the area, potentially into the KC metro area. An
increasing low level jet overnight may allow for a few elevated
showers and storms along the southwest flank of this MCS back
into northern Oklahoma. These storms may also attempt to move
into the area after 2am however confidence is low with those
storms and some guidance keeps those storms in Oklahoma where
CIN is lower. We will be increasing the POPS west of Springfield
to account for higher precip chances now expected.
&&
.SHORT TERM /THROUGH TUESDAY/...
Issued at 1231 PM CDT Sun May 19 2024
Large-scale mid- and upper-level ridging is currently very
slowly exiting our area as broad W`ly flow moves in from the
west. A longwave trough associated with the polar jet is
situated over the Pacific NW, as seen on current water vapor
imagery. A shortwave associated with a subtropical jet max is
currently exiting NM/CO. This shortwave will be responsible for
the short-term weather threat as it moves overtop a dryline in W
TX and an E-W oriented stationary boundary across central
KS/MO. An upper- level low associated with the subtropical jet
over the east- central Pacific ocean will be responsible for the
longer term weather threat.
Above average temperatures today into early this week:
The aforementioned ridging along with clear skies and light
8-12 mph S`ly winds will allow high temperatures to reach into
the upper 80s today. Current observations are already in the
mid-80s, suggesting that some places may break 90 F.
Even though a shortwave will move through the region tonight,
the largewave pattern will remain with the WSW`ly flow of the
polar jet remaining over the northern states, allowing ridging
to persist. This, along with 850mb in the 16-18C range will
continue to keep temperatures in the mid and upper 80s Monday.
Lows will also be quite mild as thunderstorms out over the
central Plains will generate cloud cover over our region at
night. This will keep lows in the upper 60s tonight and Monday
night, with areas near the MO/KS border in the lower 70s which
is near the record low maximum.
20-50% chances of thunderstorms late tonight into Monday morning:
A robust thunderstorm complex is forecast to traverse KS today
through tonight. This complex will begin to dissipate in east KS
as it escapes upper-level support and enters more stable air
from the nocturnal boundary layer. The 12Z HREF run depicts the
complex falling apart right along the MO/KS border after 10 PM.
However, most CAMs are known to poorly handle convective cold
pools. With a substantial cold pool expected to develop with
this system in KS, the complex has a 20-50% chance to reach
further east than model guidance. Indeed, mean MUCAPE across
our region will be >1000 J/kg with 0-6 km bulk shear at 15-25
kts which would support this scenario. The MPAS models--which
use a refined microphysics scheme--seem to handle the MCS
progression better than others and brings the MCS to Hwy 65. As
such, there is a 20-50% chance of leftover stratiform rain and
embedded thunderstorms along and west of Hwy 65 with the highest
chances along the MO/KS border. These storms would be at the
I-49 corridor between 10PM-2AM timeframe and the Hwy 65
corridor by the 2-7 AM timeframe. Additionally, small hail and
isolated 60 mph wind gusts are possible along the MO/KS border
before the leading line of the MCS completely breaks apart.
Nevertheless, even if thunderstorms do not make it across the
border, at least light isolated to scattered showers should
persist until 7-9 AM at the latest.
15-30% chances of thunderstorms Monday afternoon/evening:
Given the robust convection expected across the Plains, an MCV
is likely to develop along with the thunderstorm complex and
migrate somewhere through central/northern MO. Additionally,
surface outflow from the overnight storms could also be in the
vicinity. Whereever these features set up could be the focus for
new thunderstorm development Monday afternoon into the evening.
This threat is quite conditional, however, as lift from surface
outflow and mid-level support from vorticity advection
associated with the MCV will need to overcome upper-level
subsidence due to rising heights ahead of another shortwave.
Capping may also develop across the area (20-30% chance of -50
J/kg according to the HREF), especially if a sufficient cold
pool persists across the area. These conditionalities lead to a
15-30% chance of scattered thunderstorm redevelopment along and
north of the Hwy 32 to I-44 corridor during the afternoon
hours. If storms do form, the environment will be characterized
by 1000-2000 J/kg MLCAPE and 20-30 kts of 0-6 km bulk shear
which could support a few marginally severe multicells.
Inverted-V low-level soundings suggest a few 60 mph damaging
wind gusts as the main threat, but 7.5-8.5 C/km mid-level lapse
rates would also support small to marginally severe (quarter-
size) hail.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
Issued at 1231 PM CDT Sun May 19 2024
Potential for severe storms Tuesday evening into Tuesday night:
Our greatest potential for severe weather comes Tuesday evening
through Tuesday night as the SPC has an Enhanced (3 of 5) risk
NW of a line from Pittsburg, KS to Osage Beach and a Slight (2
of 5) risk elsewhere. The aforementioned upper-level low over
the east-central Pacific will lift NE through the four corners
region. Additionally, a shortwave associated with the polar jet
will drop SE from the Pacfic NW. The two waves will somewhat
phase together, creating a unified SW`ly jet across the Plains.
This will force a greater surface mass response across the
Plains. The stronger S`ly low-level flow will advect lower 70s
dewpoints across the western area of our CWA and 19-22C 850mb
temps across the area. This will bring a hot and muggy airmass
across our area with highs in the upper 80s, potentially above
90. A surface cold front associated with the surface
cyclogenesis will drop SE from the NE/IA region into east KS and
central MO. This will force thunderstorms Tuesday evening, with
some potentially severe, within this region. These will drop SE
ahead of the front through the overnight hours.
Without a doubt, the environment will be ripe for severe
weather, especially in the Enhanced risk where mean NBM CAPE
values exceed 2000 J/kg, 0-6 km bulk shear values generally
lying within the 40-50 kt range with forecast hodographs
supporting supercells, and lapse rates in the 7.5-8.5 C/km
range. There are questions, however, in the level of forcing,
degree of capping, and evolution of convection. The greatest
upper-level forcing will be displaced to N MO/IA where the most
vigorous shortwave PVA is located. The surface cold front could
be enough lift to overcome the lack of upper-level forcing,
however, the 700 mb wave is looking to be somewhat positively-tilted
which is placing warmer temperatures the further south you go
from the mid-level shortwave. This could create a robust capping
inversion, especially across our slight risk areas, which could
shunt any convection along the cold front.
Nevertheless, if storms are to initiate along the front in east
KS/west-central MO, supercells are likely to be the initial
storm mode. This would be in the Tuesday late afternoon hours. With
a SE cold front moving at approximately 3-5 m/s and the
forecast bunkers right motion expected to be only 5 m/s faster
than the front, these storms will likely stay on the boundary.
This paired with shear vectors largely parallel to the front
will promote quick upscale growth. A line of storms is then the
most likely mode as the storms progress further into our CWA.
This means that initially, all hazard will be possible
(generally just outside our CWA, but potentially reaching into
our extreme NW counties. Then, damaging winds will be the main
threat as the line organizes and moves through our CWA. However,
there is still the potential large hail given the thermodynamic
profiles, and a spinup tornado or two given the kinematic
profiles. They are just lesser threats. A better idea of exact
hazards and intensities will be evaluated in future forecasts.
The line is expected to move through our CWA during the evening
and into the overnight hours. The cold front will slowly sag
SE, so by the morning hours, storms may not completely be out of
our CWA. The exact evolution is still in question, but latest
trends have been slower and slower making the severe threat an
overnight threat for areas east of I-49.
Potential for another round of severe storms Wednesday:
With the sagging nature of the surface cold front and the later
trend of its progression, it is forecast to be somewhere across
the I-44 corridor by midday Wednesday. This will promote highs
in the mid 70s NW of I-44, and in the lower 80s SE of I-44.
Storms may be ongoing at midday, which brings up uncertainties
in the evolution and potential redevelopment of storms ahead of
the front. Nevertheless, a very unstable airmass is expected to
be in place SE of the front (SE of I-44). The NBM mean is around
3000 J/kg with the 90th percentile pushing 5000 J/kg.
Additionally, 45-55 kts of 0-6 km bulk shear will be present
thanks to the SW`ly mid- level speed max overhead. This will be
more than enough to support organized severe thunderstorms SE of
I-44, if they can redevelop amid ongoing convection and upper-
level support being displaced well off to the north. With mean
flow being SW`ly, parallel to the surface cold front, convection
will likely be linear along the front with the potential for
training storms. This would also promote a flooding threat. The
WPC does have a Slight (2 of 4 level) risk for excessive
rainfall across south- central MO. While more details are needed
to advertise specific locations/timing/hazards, given cold
frontal forcing and parallel flow, the main hazards will likely
be damagaing winds and large hail. This will continue to be
evaluated in future forecast updates.
Unsettled weather may persist through the end of this week:
Daily max precipitation chances of 30-50% persist through the
weekend as ensembles agree on the longwave pattern producing a
trough over the west coast with a suptropical jet pumping into
the Southern Plains. This will allow multiple rounds of
showers/thunderstorms through the weekend. CSU machine learning
guidance also does place portions of our area in a 15% risk for
severe weather each day through Sunday. This guidance, however,
is based on the GEFS ensemble, which at this range is unable to
resolve shortwave features. So while the synoptic pattern exists
for showers/thunderstorms and the potential for severe weather
each day, exact timing and locations of each round will depend
on where and when ejecting shortwaves move through the area. At
this point, ensemble agreement is too low to try and pinpoint
any specific areas at any specific time.
&&
.AVIATION /00Z TAFS THROUGH 00Z MONDAY/...
Issued at 618 PM CDT Sun May 19 2024
VFR conditions are expected at the TAF sites through the period.
JLN will need to monitor thunderstorms that will approach the
TAF sites overnight. These storms should weaken as they approach
SGF. Winds will remain out of the south. Low level wind shear is
likely overnight at JLN.
&&
.CLIMATE...
Issued at 100 PM CDT Wed May 15 2024
Record High Temperatures:
May 20:
KSGF: 90/1964
KJLN: 92/1956
KUNO: 89/1964
May 21:
KSGF: 91/1987
KJLN: 91/1987
Record High Minimum Temperatures:
May 20:
KSGF: 71/1902
May 21:
KSGF: 70/1902
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
KS...None.
MO...None.
&&
$$
MESOSCALE...Burchfield
SHORT TERM...Price
LONG TERM...Price
AVIATION...Burchfield
CLIMATE...Burchfield