April 2nd-5th. Severe Weather Outbreak Round 2

[Clinton]

New week but a very similar setup to what just occurred Friday.  As of this moment there is a marginal threat Monday extending from central Texas up to KC.  @Andie @Black Hole @Iceresistance @OKwx2k4

..SUMMARY...
   Isolated to widely scattered strong storms may impact parts of the
   central and southern Great Plains late Monday afternoon and Monday
   night, posing some risk for severe weather.

   ...Synopsis...
   Models suggest that large-scale mid-level ridging developing within
   the westerlies across the mid-latitude eastern Pacific will reach
   peak amplitude by the beginning of this period.  As additional
   perturbations continue to dig to the east of this regime, inland of
   the Pacific coast, it appears that an amplifying lead short wave
   trough will pivot eastward across the Great Basin through Rockies
   vicinity.  As this occurs, large-scale downstream mid-level ridging
   is forecast to build across and to the east of the mid/upper
   Mississippi Valley, while ridging also builds near and east of the
   lower Mississippi Valley, to the north of persistent mid-level
   subtropical ridging centered near the Yucatan Peninsula.  This is
   expected to coincide with the initiation of strong cyclogenesis from
   eastern Colorado through western Kansas by late Monday night.

   A broad belt of strengthening southerly return flow will contribute
   to further low-level moistening across the lower Great Plains into
   Mississippi Valley, as far north as a stalling frontal zone in the
   wake of a short wave perturbation accelerating east-northeast of the
   Great Lakes region through the Canadian Maritimes.  This front is
   forecast to sharpen while slowly returning northward through
   southern portions of the Upper Midwest and Great Lakes region by
   late Monday night.  At the same time, as a mid-level low of Arctic
   origins lingers near/southeast of Hudson Bay, associated cold
   surface air may begin to advance southward into portions of the
   northern Great Plains and upper Great Lakes region.

  The Tuesday threat looks to be slightly further SW from the previous storm and will likely included KC and Des Moines then east toward Chicago.  KC has been in somewhat of a severe weather drought the last few years but with highs in the low 80s and a potentially well timed dry line there should be enough energy for some organized super cells. 

 ...DISCUSSION...
   Medium-range models continue to indicate that the westerlies will
   become rather amplified across the mid-latitude Pacific into western
   North America by late next week into next weekend.  It appears that
   this will include building mid-level ridging centered near the
   Pacific coast, with downstream developments a bit more unclear. 
   However, beneath at least a broadly confluent mid/upper flow, cold
   surface ridging may tend to prevail east of the Rockies, with
   generally low severe weather potential.

   Prior to these developments, strong surface cyclogenesis is forecast
   to proceed across the central Great Plains into the Upper Midwest
   Tuesday through Tuesday night, in response to a significant short
   trough emerging from the Intermountain West.  It still appears that,
   as the center of the deepening cyclone migrates from the north
   central Kansas vicinity through eastern Nebraska and western Iowa
   during the late afternoon and early evening, a trailing dryline
   advancing across the Missouri/Kansas border vicinity might provide
   one focus for intense thunderstorm initiation.  

   There remains at least some signal within the various model output
   that convection may initiate earlier within the open warm sector to
   the east, and it remains unclear what influence this might have on
   subsequent thunderstorm development.  Barring this complication, a
   period of sustained, long track discrete supercell development may
   be possible, as strong southwesterly deep-layer mean flow advects
   cells away from the dryline through the moist warm sector.  This
   probably would be accompanied by potential for strong tornadoes and
   large hail.  Thereafter, as a trailing cold front overtakes the
   dryline and surges eastward across the lower Missouri/middle
   Mississippi Valleys, an organizing squall line may be accompanied by
   strong, damaging wind gusts and a few tornadoes.

The cold side looks to produce heavy snow over the Dakotas and the snow could make its way over toward @Madtown.

Hopefully we all get a little better drink of water than the previous system as things look to really dry out in the long range.

[Tom]

0z EPS...Big Snow targeting the Dakotas into  @Beltrami Island back yard...

[gabel23]

Another dry slot for us in Nebraska. Hoping as we move forward in April we start getting something. Need a wet month around these parts.

[Iceresistance]

How has anyone forgotten April 2nd for me and @Andie?

[Beltrami Island]

7 hours ago, Tom said:

0z EPS...Big Snow targeting the Dakotas into  @Beltrami Island back yard...

Oh I've been watching this. This thing better deliver the goods for solid double digit accumulation. It's a couple weeks too late to be happy with a garden variety 6-8" storm. 

[Andie]

7 hours ago, Iceresistance said:

How has anyone forgotten April 2nd for me and @Andie?

I haven’t…..oh wait.
 

Anyway. Severe storms and risk of large hail and tornados along a warm front.   Could get nasty.  
I think you might be in a higher risk than DFW but I won’t bet on it.  
 

Very nasty storm season this year  keep your eyes open Ice!!

 

[Clinton]

1 hour ago, Andie said:

I haven’t…..oh wait.
 

Anyway. Severe storms and risk of large hail and tornados along a warm front.   Could get nasty.  
I think you might be in a higher risk than DFW but I won’t bet on it.  
 

Very nasty storm season this year  keep your eyes open Ice!!

 

 

Reed Timmer, PhD

 

@ReedTimmerAccu

 

 

Increasing threat for gorilla hail and isolated #tornado in DFW area tomorrow evening! This is my target area. Stay tuned to watches and warnings in N Texas as this could go big tomorrow

[Andie]

I can do without this !  
Don’t need to replace a roof this soon much less windows!! 

[Clinton]

6 hours ago, Andie said:

I can do without this !  
Don’t need to replace a roof this soon much less windows!! 

SPC has upgraded the Dallas/Ft. Worth area to an enhanced risk today.  All hazards are possible but it seems like large hail is the biggest threat.

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1259 AM CDT Sun Apr 02 2023

   Valid 021200Z - 031200Z

   ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR PARTS OF
   NORTH TEXAS...

   ...SUMMARY...
   Thunderstorms capable of very large hail, localized damaging winds,
   and a few tornadoes will be possible this afternoon into the early
   evening across parts of the southern Plains, with the greatest
   threat centered on north Texas.

   ...Synopsis...
   A mid/upper-level shortwave trough will move quickly eastward across
   the southern Plains during the day today, and into the Southeast
   tonight. In the wake of this feature, a large-scale upper trough
   will begin to amplify over the West. At the surface, a warm front
   will move northward across TX through the day, in response to a
   gradually deepening cyclone in the south-central High Plains. Later
   tonight, the warm front will move northward along the Gulf Coast and
   richer low-level moisture will begin returning to the lower MS
   Valley region. 

   ...North/central TX and vicinity...
   As low-level moisture increases beneath steep midlevel lapse rates,
   moderate to locally strong buoyancy will develop later today across
   much of central/north TX. Initially elevated convection is expected
   to develop by late morning or early afternoon from northwest TX into
   southwest OK, within a low-level warm advection regime ahead of the
   ejecting wave. Steep midlevel lapse rates, MUCAPE in excess of 1000
   J/kg, and sufficient deep-layer shear will support some threat for
   hail with the stronger elevated cells as they spread eastward. 

   With time, at least isolated surface-based storms are expected to
   develop this afternoon, as modest heating occurs near/south of the
   warm front, within a moistening boundary layer. Some initially
   elevated convection may become rooted in the boundary layer, while
   isolated supercell development will also be possible along an
   eastward-moving dryline. MLCAPE in the 1000-2000 J/kg range, steep
   midlevel lapse rates, and effective shear of 50+ kt will support a
   threat of very large hail with any sustained supercell, along with a
   threat of isolated severe gusts. Guidance varies somewhat regarding
   the strength of low-level flow/shear across the warm sector, but any
   sustained intense supercell would also pose some tornado threat,
   especially in closer proximity to the northward-moving warm frontal
   zone. 

   An Enhanced Risk has been added across north TX, where the greatest
   storm coverage is currently anticipated within a favorable supercell
   environment. Storm coverage becomes increasingly uncertain south of
   the Enhanced Risk area into parts of central TX, but any sustained
   supercell in this region would pose a threat of very large hail as
   well. 

[Clinton]

Mondays threat looks low as cool air will be in place north of I-70.  Large hail is possible north of the warm front.

The biggest and most widespread severe weather day is Tuesday.  All hazards possible for many on here including the metropolitan areas of KC, Chicago, STL, and Little Rock again.

 

SPC AC 020719 Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0219 AM CDT Sun Apr 02 2023 Valid 041200Z - 051200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS MUCH OF NORTHERN MISSOURI AND SOUTHEASTERN IOWA INTO CENTRAL AND NORTHERN ILLINOIS...AS WELL AS ACROSS PARTS OF NORTHEASTERN TEXAS...SOUTHEASTERN OKLAHOMA...MUCH OF NORTHWESTERN AND CENTRAL ARKANSAS INTO PARTS OF SOUTHEASTERN MISSOURI... ...SUMMARY... Severe thunderstorms appear likely to develop late Tuesday afternoon into Tuesday night across the lower Missouri Valley into southern portions of the Upper Midwest, and across parts of the southeastern Great Plains into portions of the Mid South. These could pose a risk for a few strong tornadoes, large hail and damaging wind gusts. ...Discussion ... As the mid-latitude eastern Pacific mid-level ridging gradually becomes suppressed, models indicate that downstream troughing will broaden from the Great Basin into the Mississippi Valley. The latter regime will be lead by a vigorous short wave trough, which is forecast to be accompanied by continuing strong surface cyclogenesis from the central Great Plains into the Upper Midwest, and building downstream mid-level ridging across the Upper Ohio Valley into Ontario, as well as across the northeastern Gulf of Mexico into Southeast. An intensifying southwesterly mid/upper jet (including in excess of 100 kt at 500 mb) nosing across the central Great Plains through Upper Midwest will contribute to strong deep-layer shear within the warm sector of the cyclone. At the same time, intensification of southerly lower-level flow (to 50-70+ kt around 850 mb) likely will contribute to large clockwise-curved low-level hodographs. This could potentially contribute to an environment conducive to supercells and organizing lines of clusters capable of producing strong tornadoes and damaging winds, where large-scale forcing for ascent and thermodynamic profiles can become favorable. ...Great Plains into Mississippi Valley... Currently, based on the latest model output, the quality of the low-level moisture return from the Gulf of Mexico is in some question. Surface dewpoints across much of the warm sector may mostly remain in the lower to perhaps mid 60s F, and the moistening boundary-layer may not become particularly deep. Corridors near/south of the warm frontal zone, to the north of the Missouri River, and ahead of the southeastward advancing cold front across Arkansas into southeast Missouri Tuesday evening, may become possible exceptions. During the day, models indicate a plume of high level moistening and large-scale ascent overspreading much of the warm sector, across the Ozark Plateau into middle Mississippi Valley. Forecast soundings suggest that this will be accompanied by destabilization and convection, which will contribute to saturation down into the mid-levels. It appears that this will not completely erode the capping elevated mixed-layer air, but thickening cloud cover aloft may inhibit surface heating and suppress potential thunderstorm development in the absence of lift to overcome the inhibition. Southeast of the deepening surface cyclone, near the intersection of the warm front and dryline, and beneath the dry slot, destabilization near/just ahead of the leading edge of the mid-level cooling seems to offer the best potential for the initiation of intense sustained thunderstorms. It still appears that this will be near the Missouri River, across parts of northeast Kansas/southeastern Nebraska/southwestern Iowa/northwestern Missouri, by late afternoon. This probably will include discrete supercells initially, before convection eventually grows upscale into an organizing, eastward propagating cluster along and south of the warm front. Farther south, developments are a bit more unclear. To this point, however, there has been a persistent signal within the model output that a corridor of more substantive moistening, ahead of the cold front as it overtakes the dryline and surges southeastward into the Ozark Plateau, could provide a corridor of enhanced severe weather potential by Tuesday evening. It is possible that associated destabilization may become aligned with the strong deep-layer mean flow, possibly allowing for the evolution of one or two long track supercells, ahead of a developing squall line. Day 4 risk area includes the Detroit area.

Edited April 2 by Clinton

[Clinton]

Models are looking to crush the Dakotas with snow and blizzard conditions.  There should be no shortage of water in the Missouri River this spring.

[Andie]

I agree on the hail concern. From the local Mets it’s looks like DFW will be in the critical area of the clash overhead.  
I’m expecting 3-7/8 pm to be our go time.  
The real relief is these things tend to pick up speed as they pick up complex energy and sweep east.   So, holding my breath. Just a few scattered small showers NW currently. But they can blow up fast.  
76*. Humidity 67%. Cloudy Pressure 29.81

 

[Andie]

It’s looking like Oklahoma/Texas line  will get much of this storm. The DFW area will get some when the line develops more but as of right now nothing like people north of me.  Some heavy rain, maybe some hail and that’s it unless it has some surprises in its pocket.  
Currently clouds are growing heavier but no rain.  

3:30 Edit:   Some large claps of thunder and it barely got our sidewalk wet.  
Oh well. Better luck next time.  

[Clinton]

Tuesday could be quite the day.  Long and detailed write up from EAX this afternoon.

Attention turns to Tuesday as the deep H5 trough begins to lift out
of the desert southwest with the 100+ kt jet rounding east of the
trough axis. This develops a negative tilt throughout Tuesday
morning, while dCVA and WAA remained phase ahead of the axis and
allow the surface cyclone to continue to deepen. This strengthens
southerly flow across the area. First off, this will result in
another windy day. The gradient winds alone will begin to push
advisory criteria, and if clouds clear late Monday Night, mixing
during the early morning may help bring wind gusts to near 40 kts.
This may also lead to elevated fire weather threat. Secondly, this
robust synoptic setup is expected to result in a favorable severe
thunderstorm environment. Ensemble probabilities for at least 1000
J/kg MUCAPE are above 90 percent. This will be a rather robust warm
sector, as temperatures are progged to reach the lower 80s with
dewpoints eventually climbing the into the lower 60s. Throughout the
day, the thermal boundary that stalled on Monday is pushed northward
into Iowa. As the surface cyclone deepens, surface troughing extends
across the Plains to east of the Mississippi River Valley. Most
deterministic solutions continue to depict rapid pressure falls
especially in the vicinity of the warm front. As the nose of the H5
100+ kt jet streak approaches, deep layer shear drastically
increases, and will likely see bulk shear values in the 0-6km layer
exceed 60 kts. For the most part, there is strong consensus among
model guidance with the track of the surface cyclone. There are
still differences in the strength of the surface cyclone, but only
about 4-6 mb. These differences likely will not make a big
difference in the impacts expected from this system. The main
question is how long does it take for shower and thunderstorm
activity to start. As was the case with this past Friday`s event,
there will likely be a pseudo dryline that comes through prior to
the main cold front, dropping dewpoints but keeping temperatures in
the upper 70s to lower 80s. Isentropic ascent may continue, and
could foster some shower development Tuesday morning. Currently,
synoptic scale models are not overly excited with producing rain
Tuesday morning for our forecast area. Most of the QPF comes after
18z, essentially waiting for peak heating. Analysis of GFS model
soundings does show a strong EML advecting in from 775mb and upward
with the southwesterly mid-level flow ahead of the main trough, and
provides a stronger a cap across a large portion of the warm sector
that is ahead of the pseudo dryline. The convergence along the
surface cyclone and cold front will likely be needed to lift parcels
past this cap. Given the strong dynamics of this system though,
would not be surprised if a weak vorticity max ejects from the main
PV anomaly, and provides some forcing for elevated storms early
Tuesday afternoon. However, the main show and severe weather threat
will need to wait for surface based convection. Once the cap erodes,
the warm sector throughout much of the lower Missouri River Valley
will have mid-level lapse rates between 7.5 to 8.5 C/km, with nearly
dry adiabatic boundary layers. With respect to wind shear, current
model hodographs are showing strong cyclonic shear in the lowest 0-
1km in areas near the center of the surface cyclone, mainly where
the surface winds are backed to the southeast. There are few points
that also show a veer-back profile in the vicinity of the warm front
and surface cyclone center. Right now, this is favored north of Hwy
36 from NE Kansas into southern Iowa (essentially the northern
enhanced risk in the SPC Day 3 outlook). This would be the favored
area for discrete supercell storm mode, with areas further south
looking at more linear storm along the cold front. A secondary area
south of Interstate 44 associated with a secondary vort max could
also favor this, but this is not currently depicted in our forecast
area. If the environment remains favorable for a discrete storm mode
Tuesday afternoon into early evening, supercells will be capable of
all threats. Areas along the cold front with the linear storm mode
would mainly be damaging winds, but will need to monitor surges and
inflections and how it orients with the 0-3km shear vector, as the
bulk shear values in this layer will exceed 40 kts later in the
evening as the LLJ kicks in. If the warm front does not surge as
quickly, or the H5 short-wave closes off sooner and lifts
differently then currently progged, this will likely change where
favorable low-level cyclonic shear sets up, and could change the
area of the discrete storm threat. The 00z CAMs this evening may
provide us some of the first hints on this potential. The CAMs this
evening will also provide the opportunity to dive into smaller scale
details, storm motion, storm inflow, etc. Confidence is medium-high
in the occurrence of strong to severe storms across the area, medium
confidence in the specific threats and low-medium in timing. Severe
storms could start early afternoon, and it is possible a severe
threat continues into the late evening.

[Clinton]

18z NAMNST coming in hot

[Clinton]

Moderate risk area put out by the SPC, same areas hit last week.

 Valid 041200Z - 051200Z

   ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS LATE TUESDAY
   AFTERNOON AND EVENING ACROSS PARTS OF NORTHEASTERN MISSOURI INTO
   SOUTHEASTERN IOWA...NORTHWESTERN AND WEST CENTRAL ILLINOIS...

   ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS SURROUNDING THE
   MODERATE RISK ACROSS MUCH OF NORTHERN MISSOURI....CENTRAL AND
   EASTERN IOWA...NORTHWESTERN AND CENTRAL ILLINOIS...AS WELL AS PARTS
   OF NORTHEASTERN TEXAS...SOUTHEASTERN OKLAHOMA...MUCH OF
   ARKANSAS...INTO SOUTHERN MISSOURI...

   ...SUMMARY...
   Severe thunderstorms appear likely to develop late Tuesday afternoon
   into Tuesday night across the lower Missouri Valley into southern
   portions of the Upper Midwest, and across parts of the southeastern
   Great Plains into portions of the Mid South.  These could pose a
   risk for a few strong tornadoes, large hail and damaging wind gusts.

   ...Synopsis...
   As initially amplified mid-level ridging over the mid-latitude
   eastern Pacific gradually becomes suppressed, models indicate that
   downstream troughing will broaden from the Great Basin into the
   Mississippi Valley.  This will be lead by a vigorous short wave
   trough, which is forecast to be accompanied by continuing strong
   surface cyclogenesis from the central Great Plains into the Upper
   Midwest, and building downstream mid-level ridging across the Upper
   Ohio Valley into Ontario, as well as across the northeastern Gulf of
   Mexico into Southeast.

   An intensifying southwesterly mid/upper jet streak (including speeds
   in excess of 100 kt at 500 mb) nosing across the central Great
   Plains through Upper Midwest will contribute to strong deep-layer
   shear within the warm sector of the cyclone.  At the same time,
   intensification of southerly lower-level flow (to 50-70+ kt around
   850 mb) likely will contribute to large clockwise-curved low-level
   hodographs.  This could potentially contribute to an environment
   conducive to supercells and organizing lines or clusters capable of
   producing strong tornadoes and damaging winds, where large-scale
   forcing for ascent and thermodynamic profiles can become favorable.

   However, among a number of substantive lingering uncertainties, the
   quality of the boundary-layer moisture return from the Gulf of
   Mexico remains in question.  Due to (at least initially) relatively
   shallow boundary-layer depth, downward mixing of drier air might
   impact sizable pockets of the potentially broad warm sector through
   the day, based on model output.  Also, ahead of the mid/upper
   troughing, destabilization associated with large-scale ascent and an
   influx of high-level moisture from the subtropical Pacific may
   contribute to convective development which tends to saturate and
   stabilize lapse rates down into the mid-levels, across much of the
   Ozark Plateau into middle Mississippi Valley.  While it appears that
   this will not completely erode the capping elevated mixed-layer air,
   thickening cloud cover aloft may inhibit surface heating and
   suppress potential thunderstorm development in the absence of lift
   to overcome the inhibition.

   ...Great Plains into the Mississippi Valley...
   Both the latest NAM and Rapid Refresh appear increasingly suggestive
   that the dryline could surge east-northeastward across southwestern
   Iowa and northwestern/west central Missouri, at least above the
   surface, by mid to late afternoon, in response to the progression of
   at least one speed maximum within the mid-level flow.  Model output
   generally indicates that largest CAPE will become focused ahead of
   this feature, and south of the warm front advancing northward across
   central Iowa/northern Illinois during the late afternoon.  And the
   dryline might provide a focus for sustained discrete supercell
   development with the potential to produce strong tornadoes while 
   propagating northeastward across northeastern Missouri and
   southeastern Iowa into northwestern and west central Illinois
   through early evening.

   In the wake of this activity, as the cold front begins to overtake
   the dryline and advance southeastward, various model output
   continues to suggest that the evolution of an organizing line or
   cluster of storms is possible.  This may pose a risk for large hail,
   damaging wind gusts, and perhaps a few tornadoes while propagating
   east-southeastward across the lower Missouri/middle Mississippi
   Valley vicinity into Tuesday night.

   Farther south, developments initially along the dryline and then
   ahead of the southeastward advancing cold front remain a bit more
   unclear.  However, there has been a persistent signal within the
   model output that a narrow corridor of more substantive
   boundary-layer moistening could provide a focus for enhanced severe
   weather potential by Tuesday evening.  It is possible that
   associated destabilization may become aligned with the strong
   deep-layer mean flow, possibly allowing for the evolution of one or
   two long track supercells, ahead of a developing squall line.

[Clinton]

Storms, with the worst looking to be just NE of mby.  Very dry air west of the dryline I wish Kansas could get a drink, that drought area will grow.  Regardless it will be windy.

[Tom]

0z Euro...cutting it a bit to far NW for our MN peeps to reel in the higher totals... @Beltrami Island

 

 

[CentralNebWeather]

The dreaded dry slot will lead to fire concerns and blowing dust in places with extremely high winds.  I have been one of the lucky ones with winter precipitation, but many continue in the long drought.  NWS Hastings says little to nothing for rainfall for the next 2 weeks.  Unfortunately, we've seen this movie played way to often in the last 2 years.  We have to hope that the coming El Nino will provide much better moisture around here going forward.

[Beltrami Island]

5 hours ago, Tom said:

0z Euro...cutting it a bit to far NW for our MN peeps to reel in the higher totals... @Beltrami Island

 

 

Grand Forks hasn't committed to any amounts yet in my point forecast.  Just to the east, the Duluth office has 11- 22 in the point forecast.  Near 50 by the weekend is going to make for one heck of a mess even if 11 happens. 

[Clinton]

Anybody else going to be chasing tomorrow?  @OmahaSnowFan

Reed Timmer, PhD

 

@ReedTimmerAccu

 

 

Targeting Des Moines tomorrow to start for tornado outbreak. Sticking to the warm frontal zone. Dangerous storm chase once again but storm motions should be closer to 40 knots. Unfortunately, the same areas ravaged by Friday’s tornadoes could be impacted again. Stay tuned to watches and warnings tomorrow

https://www.facebook.com/reedtimmer2.0/videos/243150154836258

[Andie]

Your map reminds me of an article I read a few days ago addressing how “tornado alley” has shifted.  
The spring storms in Texas have changed recently. They’re less prone to circulation.  We get more threat of hail than anything and often it isn’t as bad as forecast.  

I would love for someone to weigh into why tornado alley has moved east after being in the center of the country for so long. And is it long term or a brief anomaly? 
 

 

[OmahaSnowFan]

6 hours ago, Clinton said:

Anybody else going to be chasing tomorrow?  @OmahaSnowFan

Reed Timmer, PhD

 

@ReedTimmerAccu

 

 

Targeting Des Moines tomorrow to start for tornado outbreak. Sticking to the warm frontal zone. Dangerous storm chase once again but storm motions should be closer to 40 knots. Unfortunately, the same areas ravaged by Friday’s tornadoes could be impacted again. Stay tuned to watches and warnings tomorrow

https://www.facebook.com/reedtimmer2.0/videos/243150154836258

Yep, I’ll be out chasing again!

[Phil]

@Timmy Supercell  

[Clinton]

Impactful weather day ahead.  The tornado threat for mby will depend on if any storms can break through the cap later this afternoon.  A squall line will likely move through overnight and it looks like some to my NE could have tornados after dark.

[Clinton]

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0104 AM CDT Tue Apr 04 2023

   Valid 041200Z - 051200Z

   ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS THERE IS A
   MODERATE RISK OF SEVERE THUNDERSTORMS FROM EASTERN IOWA INTO
   NORTHWEST ILLINOIS AND NORTHEAST MISSOURI...AND FROM SOUTHERN
   MISSOURI SOUTHWESTWARD TOWARD THE ARKLATEX...

   ...SUMMARY...
   A large area of severe potential will develop today into tonight,
   from eastern portions of the Plains into the Missouri and mid/upper
   Mississippi Valleys. Strong, potentially long track tornadoes are
   possible, in addition to large hail and damaging winds. Both
   afternoon and overnight potential is expected across various
   regions, including the risk of dangerous nighttime tornadoes.

   ...Synopsis...
   A deep upper trough will move from the Intermountain West/Rockies
   toward the Great Plains today. Within the large-scale trough, an
   upper cyclone will deepen as it moves northeastward toward the
   Dakotas. An 80-100 kt midlevel jet will overspread the central
   Plains during the afternoon/evening, while a secondary jet maximum
   intensifies through the day from the southern Plains into parts of
   the Midwest. At the surface, a broad cyclone will gradually
   consolidate and deepen as it propagates from the central High Plains
   toward western IA by early evening. A warm front will move northward
   into central/northern IA and northern IL by late afternoon, and into
   parts of WI/lower MI late tonight. A dryline will extend southward
   across eastern portions of the central/southern Plains, with a cold
   front expected to sweep through the Plains/Midwest this evening into
   the overnight. 

   ...Iowa into parts of the Great Lakes states...
   Short-term guidance continues to vary greatly regarding the extent
   of mixing across the warm sector over parts of the Midwest later
   today. The typically overmixed RAP/HRRR drop surface dewpoints to
   near 60F south of the warm front as temperatures warm to near 90F,
   while the generally undermixed NAM maintains cooler temperatures and
   upper 60s F dewpoints across the warm sector, and is slower to
   advance the warm front northward. The current expectation is for the
   magnitude of mixing to be somewhere between these two extremes, with
   dewpoints remaining in the mid 60s in closer proximity to the warm
   front, with somewhat stronger mixing possible farther south. 

   Considerable spread remains regarding convective evolution among
   regional/global guidance and CAMs. However, two areas of possible
   storm initiation this afternoon are evident. The first is near the
   MO/IA/IL border region, where substantial warming/moistening beneath
   steep midlevel lapse rates will result in rapid destabilization
   near/south of the warm front. Any supercell that develops in this
   region during the afternoon will pose a threat of very large to
   giant hail. Very favorable low-level and deep-layer shear will
   support a threat of strong tornadoes as well for as long as any
   supercell traverses the warm sector along/south of the warm front. 

   The second area of potential initiation will be farther west across
   west-central IA, closer to the surface low. Some uncertainty remains
   regarding the moisture quality this far west, but moderate buoyancy
   and very favorable wind profiles will support a threat of supercells
   capable of all severe hazards, including the potential for a strong
   tornado or two with any cell that can persist in the warm sector.

   Additional convection may develop later tonight in association with
   the cold front and move into the region, posing a threat of hail and
   damaging gusts. A conditional tornado threat will also persist
   overnight with any sustained supercells. 

   Finally, storms capable of hail will be possible north of the warm
   front, where MUCAPE in excess of 1000 J/kg, steep midlevel lapse
   rates, and sufficient deep-layer shear will support elevated
   supercell potential, despite rather cold surface temperatures.

   ...Southern Plains into the Ozark Plateau...
   A very favorable severe thunderstorm environment will also reside
   across the southern Plains into the Ozark Plateau, beginning this
   afternoon and persisting overnight east of the dryline/cold front.
   Diurnal storm development along the dryline is expected to be
   isolated at best, with large-scale ascent remaining weak for much of
   the day. However, convection is expected to increase this evening
   and especially overnight from northeast TX into AR and southern MO,
   within a persistent low-level moist plume associated with a strong
   low-level jet. 

   Moderate buoyancy and very favorable wind profiles will support
   supercells, both with diurnal storms (if any develop) and nocturnal
   convection. Some nocturnal storms may be somewhat elevated (at least
   initially) and the mode may be a mix of discrete cells and clusters,
   but weak MLCINH will not prohibit surface-based convection, and the
   current expectation is for supercell potential to increase
   overnight. Any nocturnal supercells will be capable of all severe
   hazards, and the concern remains regarding the potential for
   nocturnal strong tornadoes from near the ArkLaTex region into parts
   of southern MO.

Enhanced risk tomorrow for the lower lakes down through the Ohio Valley.

   Day 2 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1233 AM CDT Tue Apr 04 2023

   Valid 051200Z - 061200Z

   ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS WEDNESDAY
   ACROSS MUCH OF THE LOWER GREAT LAKES REGION AND OHIO VALLEY...

   ...SUMMARY...
   Scattered severe storms posing a risk for strong tornadoes and large
   hail are expected in a corridor across eastern Illinois through
   Lower Michigan Wednesday, with organizing clusters or lines of
   storms accompanied by potentially damaging wind gusts, and perhaps a
   couple of tornadoes, across the Ohio Valley vicinity.

   ...Synopsis...
   Within the more amplified branch of split flow emanating from the
   mid-latitude Pacific, the center of a broad and deep, occluding
   cyclone is forecast to migrate across and northeast of the Lake
   Superior vicinity before beginning to weaken Wednesday through
   Wednesday night.  As this occurs, it appears that mid-level ridging
   centered along an axis across the Yucatan Peninsula into western
   Atlantic will remain a prominent influence across much of the
   Southeast, while short wave ridging also overspreads the Northeast
   and Canadian Maritimes.

   Models indicate a corridor of deepening boundary-layer moisture
   overspreading the Ozark Plateau and middle Mississippi Valley, into
   the Lake Michigan vicinity, by early Wednesday.  This is forecast to
   spread across much of the lower Great Lakes and Ohio Valley, ahead
   of the cold front trailing the cyclone, while the trailing flank of
   the front stalls across the lower Mississippi Valley into
   northwestern Gulf coastal plain, beneath the northwestern periphery
   of the mid-level ridging.

   ...Illinois through lower Michigan...
   Beneath a dry slot overspreading the region, south and east of an
   intensifying cyclonic mid-level jet (in excess of 120 kt around 500
   mb), surface heating and steepening mid-level lapse rates are
   expected to contribute to sufficient destabilization for
   intensifying supercells. This may commence in a pre-frontal corridor
   as early as mid Wednesday morning across parts of central into
   northeastern Illinois, before developing into/across Lower Michigan
   and parts of adjacent northern Indiana and northwestern Ohio through
   late afternoon. 

   It remains unclear what effect the cooler marine layer from Lake
   Michigan has on adjacent coastal areas, particularly into portions
   of western Michigan.  However, Rapid Refresh forecast soundings, in
   particular, indicate a rather potent thermodynamic and kinematic
   environment supportive of strong tornadoes.  This includes sizable
   CAPE, strong deep-layer shear and large clockwise-curved low-level
   hodographs.  It is possible that severe weather probabilities could
   still be increased further in later outlooks for this period.

   ...Ohio Valley...
   To the south of the dry slot (within a plume of seasonably high
   precipitable water, and generally aligned with a belt of 40-70 kt
   west-southwesterly flow in the 850-500 mb layer), models indicate
   the potential for more widespread convection, organizing into
   clusters or lines while overspreading much of the Ohio Valley
   through the day.  While lapse rates may not be particularly steep,
   given the strong flow, with at least modest CAPE and the increased
   potential for heavy precipitation loading and organizing convection,
   the environment probably will become conducive to damaging surface
   gusts, in addition to some risk for tornadoes.

[westMJim]

Most of lower Michigan is now in the enhanced risk area for Wednesday. We shall see how this plays out. It also looks like Wednesday will be the warmest day of 2023 so far. Thursday looks to be windy and much cooler.

[Black Hole]

I'm probably on the outside looking in by the look of things again today. A few cells could pop up over southeast OK in the warm sector this afternoon, moving northeast. The front will probably light up right as it passes my area near midnight. One of these days..

[Hawkeye]

A cluster of strong storms has popped over southeast Iowa and is moving into my area.  It's pretty chilly outside so hail is the primary threat.

[tStacsh]

crazy run by the HDRPS

[Hawkeye]

The hail core of this storm just passed a mile or two to my east.  I got pea size hail, but 1.00-1.75" hail fell from south to northeast Cedar Rapids and Marion.

[tStacsh]

Tomorrow could be a very rare event for Michigan.  

[Hawkeye]

2.50" diameter hail has been reported in Davenport.

[Hawkeye]

17 minutes ago, Hawkeye said:

2.50" diameter hail has been reported in Davenport.

Now 3.00" hail and 80 mph wind in Davenport/Moline.

[Stormy]

17 minutes ago, Hawkeye said:

Now 3.00" hail and 80 mph wind in Davenport/Moline.

That storm got big while the others weakened or died. 

[Stormy]

And now it's tornado warned with temperatures only around 50⁰!

[Hawkeye]

The Quad Cities airport recorded a 90 mph wind gust.

[WinterSquall23]

Pic of lightning  from a video I took a few years ago.  Sounded like a gun going off.  We were so close to it you can see the streamers as it evaporated.  Danger close! 

[FV-Mike]

Huge hail here in Plano,il

 

[Tom]

1 hour ago, FV-Mike said:

Huge hail here in Plano,il

 

My sister reported 1” hail also…

[Iceresistance]

4 hours ago, Hawkeye said:

The Quad Cities airport recorded a 90 mph wind gust.

Saw a delayed report of 4-inch hail in the Quad Cities

[Stormy]

Wow look at the temperature contrast!

 

[Iceresistance]

16 minutes ago, Sparky said:

Wow look at the temperature contrast!

 

Is Northern Missouri literally hotter than Oklahoma??

[macminey2]

Looks like a significant widening of the spc northern “moderate risk” zone. To including more of central Iowa.  Surprised I’m under a tornado watch though - just doesn’t feel likely here in NW / NCentral IA.

[Madtown]

Thundersnow at 1.5" down in the last hour

[Stormy]

9 minutes ago, Iceresistance said:

Is Northern Missouri literally hotter than Oklahoma??

Kind of depends where in Oklahoma.

 

[Iceresistance]

1 minute ago, Sparky said:

Kind of depends where in Oklahoma.

 

I'm in Central Oklahoma, but WOW!

[East Dubzz]

25 minutes ago, macminey2 said:

Looks like a significant widening of the spc northern “moderate risk” zone. To including more of central Iowa.  Surprised I’m under a tornado watch though - just doesn’t feel likely here in NW / NCentral IA.

Im hoping you’re right with the tornado part. I’d like some nice storms, but no thanks on tornados around here!

[East Dubzz]

Things don’t seem too crazy so far?

[Clinton]

Severe thunderstorm watch for the KC metro.  Models indicate a squall line pushing through around midnight.