Severe Weather 4-4-23 and 4-5-23

[MNstorms]

Looks like I might get a hail threat. Not sure I've seen 2000 - 3000 CAPE without any at the surface. 

[WxSynopsisDavid]

Something just appears off with these runs this morning. Mixing issues and capping issues are more prevalent right now. Concerning Wednesday, the HRRR has very little STP and parameters for the OH/TN Valley which seems odd.

[Radtechwxman]

3 minutes ago, WxSynopsisDavid said:

Something just appears off with these runs this morning. Mixing issues and capping issues are more prevalent right now. Concerning Wednesday, the HRRR has very little STP and parameters for the OH/TN Valley which seems odd.

I thought the same thing. Might just be the HRRR being special. Just crazy that it's been so consistent then derails now. Definitely something to watch. 

[WxSynopsisDavid]

2 minutes ago, StormChaser4Life said:

I thought the same thing. Might just be the HRRR being special. Just crazy that it's been so consistent then derails now. Definitely something to watch. 

The 3k NAM rolling in right now is equally bad. Tries to pop rogue cells in Georgia while keeping everything else linear.

[HillsdaleMIWeather]

IWX with one of the most strongly worded AFD's I've seen them issue in years 

 

[HillsdaleMIWeather]

21 minutes ago, WxSynopsisDavid said:

Something just appears off with these runs this morning. Mixing issues and capping issues are more prevalent right now. Concerning Wednesday, the HRRR has very little STP and parameters for the OH/TN Valley which seems odd.

Morning AFDs states that the NWS knows about these issues, the HRRR and other CAM are underplaying the environment according to IWX and others, 

[Radtechwxman]

25 minutes ago, WxSynopsisDavid said:

The 3k NAM rolling in right now is equally bad. Tries to pop rogue cells in Georgia while keeping everything else linear.

That's why it's convecting earlier because of the extreme mixing occurring. Hopefully doesn't come to fruition. 3km nam convects in ne MO into se IA but later than it was showing before and it looks to struggle. 

[SolidIcewx]

1 hour ago, HillsdaleMIWeather said:

IWX with one of the most strongly worded AFD's I've seen them issue in years 

 

What a morning read for tomorrow for the MI/IN,OH area. Tomorrow it’s going to be interesting not very often you get a hatched area over this part of the country. Also the fact that there is still room for upgrade in severe probabilities. Last MDT for SE Michigan was a bust on the very east side if I remember correctly 

[SolidIcewx]

Are there any analogs I can read into for Wednesdays event? It does concern me with the sig tornado area. Not sure how Detroit metro would react if a strong long tracked tornado came thru. Something I’ve thought about for years

[A-L-E-K]

hoping 4 more sick footage today

[Powerball]

DTW poured quite a bit of cold water on the potential Wednesday, FWIW.

It wouldn't be a early season severe weather setup if it came easy...

000
FXUS63 KDTX 040812
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
412 AM EDT Tue Apr 4 2023

.DISCUSSION...

On Wednesday, Southeast Michigan will be well positioned within a
strongly sheared warm sector as all indications are that surface
temperatures will reach the lower 70s and dewpoints rise into the
lower 60s. Environmental winds across the forecast area are
impressive with 55 knots down to roughly 3.0 kft agl which results
in long 0-1km and 0-2km hodograph lengths. There are a number of
items worth discussing that could have significant impacts on what
occurs. The first item is that forecast soundings from multiple
solutions favor subsidence between 3.5-7.5 kft agl. This checks out
as Southeast Michigan is unfavorably situated to the upper level jet
axis and absolute vorticity fields strongly show a period of
anticyclonic vorticity advection during the afternoon. It is the
subsidence and resultant capping inversion that maintains a narrow
CAPE profile and limits coverage of shower and thunderstorms during
the afternoon. In fact, the 00Z NAM solution is suggesting little to
no mixed layer CAPE for Metro Detroit and virtually all of the cwa
after 19Z. The second item of discussion is the upstream
convection/convective remnants that are shown by some model data to
stream out of MO Bootheel region through the far southern forecast
area after 12Z. This subset of model solutions then becomes somewhat
persistent with continued activity over or just east of the cwa as
differential heating/rain cooled air mass likely augments the model
convergence fields. This activity does also appear to be tied to the
anticyclonic shear side off of the low level jet. So there is a
considerable amount of uncertainty as to both the coverage of
thunderstorm activity and what area will see the greatest severe
weather threat. The best message at this vantage point centers on a
conditionality of the severe threat. Given the strongly sheared
profile, i.e. 0-3km SRH of 350-450 m2/s2 any deep
convection/thunderstorms that become rooted within the 0-2km layer
will have the potential to be of supercell mode and pose the threat
for significant severe weather. This includes both a strong tornado
threat and large hail of golfball or larger. Will state it again,
however, the development of deep thunderstorm activity very well
remains in question. So the message is one that the environment
tomorrow will be supportive of significant severe weather. Given the
current model consensus, it appears the greatest severe threat may
be early in the prefrontal environment between 16-20Z. Additionally,
the northern cwa could possibly see the greatest severe threat as
steep midlevel lapse rates/pseudo elevated mixed layer holds on
there the longest. Latest day2 has all of Southeast Michigan in an
enhanced risk for severe weather. Monitor future forecasts for
refinement to the messaging.

[CheeselandSkies]

HRRR is consistentlly firing a supercell in SE IA between 23 and 00Z, but soundings around it are still either super mixed or have a weird low-level inversion. The favorable  environment might exist only right on the warm front, where it's impossible to get an uncontaminated sounding. Low-level shear is monstrous in any case, though.

It is also showing some mid-morning convection in the area which you'd think might alleviate the mixing issue, but so far it doesn't seem to be according to the model.

[cyclone77]

DVN is definitely taking this pretty serious..

...Dangerous Severe Weather Today and Tonight...

Be Weather Aware!

Today and tonight: Volatile and dangerous day ahead with an
intense cyclone tracking from CO to se MN. This system will have
all the ingredients necessary for severe storms including long-
lived supercells producing strong to possibly violent tornadoes,
giant hail of 2 inches or greater in diameter (hen egg or larger),
and damaging winds of over 75 mph. The wind fields will be very
strong with a LLJ of 60-70 kts, and an h250 jet of 170 kts! Deep
layer shear will be very strong and SRH values of at least 500
J/kg. More than enough for the potential for long-track tornadoes,
especially later this afternoon and into the overnight hours
(even more dangerous!). The warm front will lift northward across
the cwa which will be key to the location of the strongest
tornadoes. Afternoon temps will range from the lower 60s along Hwy
20 to the lower to mid 80s in our southern counties. Dewpoints
are expected to be in the lower to mid 60s, similar to last
Friday`s event. Today`s temps will be warmer than on Friday and
thus CAPE values will be more favorable for explosive development.
We will also need to keep an eye on the strength of the cap.
Later tonight is when the strong cold front/dry line arrives.

Now let`s dig more into the severe details: CAM`s suggest 3 rounds
of severe storms. Round 1) This morning scattered elevated
supercells producing large hail until about noon. This is when
the LLJ strengthens to 40 kts with deep layer shear strengthening
and frzg lvls about 11k ft which is ideal for severe hail. Round
2) Later this afternoon/evening the cap begins to break and
supercells develop with all modes of dangerous severe weather
occurs as mentioned above. Round 3) After midnight a squall line
accompanies the strong cold front/dry line with the potential for
damaging winds/QLCS tornadoes. Can`t rule out supercells with
strong tornadoes during the night due to the very strong
shear/wind fields.

[SolidIcewx]

1 hour ago, Powerball said:

DTW poured quite a bit of cold water on the potential Wednesday, FWIW.

It wouldn't be a early season severe weather setup if it came easy...

000
FXUS63 KDTX 040812
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
412 AM EDT Tue Apr 4 2023

.DISCUSSION...

On Wednesday, Southeast Michigan will be well positioned within a
strongly sheared warm sector as all indications are that surface
temperatures will reach the lower 70s and dewpoints rise into the
lower 60s. Environmental winds across the forecast area are
impressive with 55 knots down to roughly 3.0 kft agl which results
in long 0-1km and 0-2km hodograph lengths. There are a number of
items worth discussing that could have significant impacts on what
occurs. The first item is that forecast soundings from multiple
solutions favor subsidence between 3.5-7.5 kft agl. This checks out
as Southeast Michigan is unfavorably situated to the upper level jet
axis and absolute vorticity fields strongly show a period of
anticyclonic vorticity advection during the afternoon. It is the
subsidence and resultant capping inversion that maintains a narrow
CAPE profile and limits coverage of shower and thunderstorms during
the afternoon. In fact, the 00Z NAM solution is suggesting little to
no mixed layer CAPE for Metro Detroit and virtually all of the cwa
after 19Z. The second item of discussion is the upstream
convection/convective remnants that are shown by some model data to
stream out of MO Bootheel region through the far southern forecast
area after 12Z. This subset of model solutions then becomes somewhat
persistent with continued activity over or just east of the cwa as
differential heating/rain cooled air mass likely augments the model
convergence fields. This activity does also appear to be tied to the
anticyclonic shear side off of the low level jet. So there is a
considerable amount of uncertainty as to both the coverage of
thunderstorm activity and what area will see the greatest severe
weather threat. The best message at this vantage point centers on a
conditionality of the severe threat. Given the strongly sheared
profile, i.e. 0-3km SRH of 350-450 m2/s2 any deep
convection/thunderstorms that become rooted within the 0-2km layer
will have the potential to be of supercell mode and pose the threat
for significant severe weather. This includes both a strong tornado
threat and large hail of golfball or larger. Will state it again,
however, the development of deep thunderstorm activity very well
remains in question. So the message is one that the environment
tomorrow will be supportive of significant severe weather. Given the
current model consensus, it appears the greatest severe threat may
be early in the prefrontal environment between 16-20Z. Additionally,
the northern cwa could possibly see the greatest severe threat as
steep midlevel lapse rates/pseudo elevated mixed layer holds on
there the longest. Latest day2 has all of Southeast Michigan in an
enhanced risk for severe weather. Monitor future forecasts for
refinement to the messaging.

Even tho NAM has not been the greatest in the last bit. They won’t call anything significant until tomorrow if it plays out

[madwx]

Looking like 3 potential rounds here.  Mid day hailers.  Potential surface based supercells around 7-10 pm and then a broken line of storms mid morning tomorrow 

[OrdIowPitMsp]

Probably will be too far north for severe and too far south for snow. 

[madwx]

38 minutes ago, madwx said:

Looking like 3 potential rounds here.  Mid day hailers.  Potential surface based supercells around 7-10 pm and then a broken line of storms mid morning tomorrow 

The mid day elevated hailers are forming over south central Iowa.  Should be up here in 4 hours or so 

[Lightning]

2 hours ago, Powerball said:

DTW poured quite a bit of cold water on the potential Wednesday, FWIW.

It wouldn't be a early season severe weather setup if it came easy...

000
FXUS63 KDTX 040812
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
412 AM EDT Tue Apr 4 2023

.DISCUSSION...

On Wednesday, Southeast Michigan will be well positioned within a
strongly sheared warm sector as all indications are that surface
temperatures will reach the lower 70s and dewpoints rise into the
lower 60s. Environmental winds across the forecast area are
impressive with 55 knots down to roughly 3.0 kft agl which results
in long 0-1km and 0-2km hodograph lengths. There are a number of
items worth discussing that could have significant impacts on what
occurs. The first item is that forecast soundings from multiple
solutions favor subsidence between 3.5-7.5 kft agl. This checks out
as Southeast Michigan is unfavorably situated to the upper level jet
axis and absolute vorticity fields strongly show a period of
anticyclonic vorticity advection during the afternoon. It is the
subsidence and resultant capping inversion that maintains a narrow
CAPE profile and limits coverage of shower and thunderstorms during
the afternoon. In fact, the 00Z NAM solution is suggesting little to
no mixed layer CAPE for Metro Detroit and virtually all of the cwa
after 19Z. The second item of discussion is the upstream
convection/convective remnants that are shown by some model data to
stream out of MO Bootheel region through the far southern forecast
area after 12Z. This subset of model solutions then becomes somewhat
persistent with continued activity over or just east of the cwa as
differential heating/rain cooled air mass likely augments the model
convergence fields. This activity does also appear to be tied to the
anticyclonic shear side off of the low level jet. So there is a
considerable amount of uncertainty as to both the coverage of
thunderstorm activity and what area will see the greatest severe
weather threat. The best message at this vantage point centers on a
conditionality of the severe threat. Given the strongly sheared
profile, i.e. 0-3km SRH of 350-450 m2/s2 any deep
convection/thunderstorms that become rooted within the 0-2km layer
will have the potential to be of supercell mode and pose the threat
for significant severe weather. This includes both a strong tornado
threat and large hail of golfball or larger. Will state it again,
however, the development of deep thunderstorm activity very well
remains in question. So the message is one that the environment
tomorrow will be supportive of significant severe weather. Given the
current model consensus, it appears the greatest severe threat may
be early in the prefrontal environment between 16-20Z. Additionally,
the northern cwa could possibly see the greatest severe threat as
steep midlevel lapse rates/pseudo elevated mixed layer holds on
there the longest. Latest day2 has all of Southeast Michigan in an
enhanced risk for severe weather. Monitor future forecasts for
refinement to the messaging.

 

48 minutes ago, SolidIcewx said:

Even tho NAM has not been the greatest in the last bit. They won’t call anything significant until tomorrow if it plays out

 

Really makes sense.  Day 2 events are so dependent around here on what happens during Day 1 to the west.   Seen way to many Day 2 events be nothing more a windy rain shower without even thunder.   Even the SPC noted the Great Lakes could impact it:

It remains unclear what effect the cooler marine layer from Lake
   Michigan has on adjacent coastal areas, particularly into portions
   of western Michigan. 

 

[SolidIcewx]

1 minute ago, Lightning said:

 

 

Really makes sense.  Day 2 events are so dependent around here on what happen during Day 1 to the west.   Seen way to many Day 2 events be nothing more a windy rain shower without even thunder.   Even the SPC noted the Great Lakes could impact it:

It remains unclear what effect the cooler marine layer from Lake
   Michigan has on adjacent coastal areas, particularly into portions
   of western Michigan. 

 

It definitely does. If it plays out good I might even go chase and leave work early. It’s been awhile since we had a big boy around here which concerns me with how people would react to an actual supercell moving thru. I don’t blame DTX holding off the trigger till tomorrow. I hope crapvection is done by mid morning so the atmosphere can can more unstable

[BuffaloWeather]

When was the last day 2 10% hatched tornado probs in michigan/ohio/indiana? 

[SolidIcewx]

3 minutes ago, BuffaloWeather said:

When was the last day 2 10% hatched tornado probs in michigan/ohio/indiana? 

I remember a MDT risk area a few years back but the line of storms fizzled as it got east of AA. The Sig Tor has my eyes and ears perked

[hawkeye_wx]

An elevated hailer is approaching Cedar Rapids this morning, currently warned for 1" hail.

[mob1]

Morning convection is pretty scattered, might not help alleviate mixing issues most models show. Interesting day ahead, parameters warrant the moderated risk but it's one of those days that can easily yield very little with the capping issues advertises (and whatever does develop might struggle to become surface based). 

 

On the flip side of this, spacing likely won't be an issue and if cells can take advantage of the environment they can go bunkers. Definitely high bust potential, but can also end up being a big day if just a few cells can really get going. 

[Lightning]

10 minutes ago, hawkeye_wx said:

An elevated hailer is approaching Cedar Rapids this morning, currently warned for 1" hail.

1" will do some damage.  How did it turn out for you?  Those storms are moving fast.

[bdgwx]

The SPC is thinking the CAMS are mixing out the PBL too much.  Anyway, this is a pretty strongly worded discussion in regards to the potential for strong tornadoes. Some consideration of a high risk seems to have occurred, but due to uncertainties mentioned in the discussion it was rejected on this update cycle.

Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0754 AM CDT Tue Apr 04 2023

   Valid 041300Z - 051200Z

   ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS OVER PARTS OF
   EASTERN IOWA...NORTHWESTERN ILLINOIS...EXTREME SOUTHWESTERN
   WISCONSIN...NORTHEASTERN AND SOUTHERN MISSOURI...ARKANSAS...AND
   EXTREME EASTERN OKLAHOMA...

   ...SUMMARY...
   Tornadoes, severe thunderstorm gusts and large hail are possible
   today and tonight from the Upper Great Lakes to central Texas. 
   Potential for unusually strong tornadoes is focused today over parts
   of the mid/upper Mississippi Valley, and tonight over parts of the
   Ozarks to the Arklatex region.

   ...Synopsis...
   The dominant upper-tropospheric feature for this forecast will be a
   synoptic-scale trough and broad swath of associated cyclonic flow
   over the western CONUS.  Moisture-channel imagery indicates that a
   cyclone aloft is forming across the Uinta Mountains/Flaming Gorge
   region of UT/WY, along the trough extending southwestward over the
   lower Colorado River Valley and northern/central Baja.  The 500-mb
   low should migrate/redevelop northeastward to the Black Hills by
   00Z, with trough across eastern CO, northern/western NM, and
   northwestern MX.  BY 12Z, the low should reach eastern ND, with
   trough across central NE, western KS, and central/southwestern NM.

   The associated surface low was analyzed at 11Z between SLN-GBD, with
   another low over southeastern CO, and a quasistationary front
   connecting them.  A warm front extended eastward from the KS low
   over central MO, southern IL and west-central KY.  A dryline was
   drawn from the same low south-southwestward over western OK,
   northwest/west-central TX, and northern Coahuila.  The KS low should
   shift northeastward to west-central IA by 00Z, with cold front
   across extreme southeastern NE to central KS.  From there, two
   branches of the cold front will become apparent:  an arctic boundary
   arching across western KS to central CO, and a Pacific front across
   the TX Panhandle to far west TX.

   The dryline should mix eastward during the day and reach
   northwestern MO, eastern KS, east-central OK, north-central TX, to
   the Rio Grande Valley between DRT-LRD.  The warm front should extend
   from the low across eastern IA, northern parts of IL/IN, and
   western/central OH.  Overnight, the Pacific front will overtake (by
   then) the quasistationary to slowly retreating dryline from
   north-south, such that by 12Z, the combined boundary will extend
   from a low over northwestern WI across eastern IA, southwestern MO,
   northwestern AR, and across northeast through south-central TX to
   near LRD.  The warm front, at that time, should extend across
   central WI, southern Lower MI, and northern OH.

   A vast area of at least marginal severe potential is evident from
   the Upper Great Lakes north of the warm front -- where hail from
   elevated thunderstorms will be the main concern -- to portions of
   central/east TX tonight as convection grows near the cold front and
   poses mainly a wind/hail threat.  Two relative concentrations of
   particularly intense and destructive tornado potential are apparent,
   but still with enough uncertainties attached to preclude
   unconditional categorical upgrade(s) at this outlook cycle.

   ...Mid/upper Mississippi Valley region, Upper Great Lakes...
   Morning convection north of the warm front will rooted in a
   favorably unstable, elevated inflow layer amid favorable deep shear,
   and will pose an isolated large-hail threat.  Episodes of additional
   thunderstorms (also offering severe hail) are possible through this
   evening in this regime.

   The main concern, however, will be this afternoon into evening east
   and southeast of the surface low, from the warm front southward
   100-200 nm into the warm sector, in and near the "moderate" area. 
   At least isolated supercells will be possible, with potential for
   strong to violent tornadoes, very large hail, and locally severe
   gusts.  A "middle ground" or consensus scenario suggests that, once
   thicker low-cloud cover erodes/advects past the area this afternoon,
   a few supercells form in and cross a warm sector characterized by
   large hodographs, strong deep shear, and climatologically rare
   buoyancy, then cross a very favorable warm-frontal zone.  MLCAPE of
   2500-3500 J/kg is possible beneath 7.5-8 deg c/km midlevel lapse
   rates and surface dewpoints at least in the mid 60s F.  Isallobaric
   forcing and related backed flow in the warm sector, within a couple
   degrees of the latitude of the low, should yield enlarged low-level
   hodographs, with effective SRH of 300-500 J/kg, exceeding 600 J/kg
   along the warm front, and 60-70 kt effective-shear magnitudes. 
   Optimal values of both CAPE and shear may be somewhat higher if the
   most aggressive progs verify, and should be very strong along the
   warm front.

   The main uncertainty involves warm-sector storm coverage and
   maturation time before crossing too deep into the warm-frontal zone
   to remain surface-based.  A big influence on this potential will be
   the extent and magnitude of moisture deficit related to vertical
   mixing.  Models are following their usual biases in this regard --
   but to somewhat of an extreme -- with (for example) WRF-based progs
   like the NAM, SREF members and some HREF members being more cool and
   moist under an EML, but ultimately developing greater density of
   storms farther south (with more maturation room) in the warm sector
   as heating erodes MLCINH.  Meanwhile RAP-based progs (including
   HRRR) develop less activity, with a deep, well-mixed boundary layer
   more suited toward wind potential evident in their forecast
   soundings.  If the EML remains strong through the afternoon, the
   deep-mixing scenario is low-probability, but lift in the warm sector
   also may be restricted.  A corridor of frontal convection also
   should develop from late afternoon into tonight from central IA to
   eastern KS, moving eastward.  This activity may include early-stage
   supercells with all severe hazards possible, but evolving to
   wind-dominant QLCS mode with a few tornadoes also possible.

   Upstream RAOBs at 00Z last night, and 850-mb moisture analysis,
   revealed a channel of dry air and shallowness of the moist boundary
   layer from the Texas Coast north-northeastward into MO -- upstream
   from today's threat area.  However, that channel was narrow, perhaps
   sampled best by the LCH RAOB among those available at this writing
   at 12Z, and may be constricted further and shunted eastward enough
   to not be a major impediment to convection, amid the synoptic mass
   response to the approaching trough.  Still, this uncertainty keeps
   the range of reasonable development scenarios too large to do much
   with the outlook as it stands, given a very favorable overall
   meso-alpha-scale setup as discussed above.

   ...Ozarks to Arklatex and central TX...
   Isolated warm-sector or dryline thunderstorms may develop before
   dark, which could become supercells with all severe hazards possible
   if they can be sustained into an increasingly moist boundary layer
   with eastward extent.  However, the greater severe threat should
   develop this evening into tonight, as deep-layer lift and the LLJ
   each increase, along with hodograph size and low-level moisture. 
   The combination of those factors will expand the CAPE/shear
   parameter space to favor long-lived supercells with a threat for
   significant (EF2+ tornadoes) at night, along with damaging hail and
   isolated severe gusts.  Surviving diurnal and/or more newly
   developed evening convection could encounter 2500-3500 J/kg MLCAPE,
   LLJ-enlarged hodographs with effective SRH 300-500 J/kg, and 1/2-km
   SRH nearly that large.

   Coverage of prefrontal/pre-dryline convection also is uncertain over
   this area because of the strong EML sampled upstream this morning by
   DRT and FWD RAOBs.  Still, associated MLCINH should hold steady or
   perhaps even diminish for a few hours this evening as boundary-layer
   theta-e increases (with upper 60s F surface dewpoints likely).  As
   the front/dryline combination impinges on the region overnight,
   thunderstorm coverage should increase along the associated corridor
   of maximized lift, with all severe hazards possible.

   ..Edwards/Smith.. 04/04/2023

[Natester]

Just had some half-inch hail as the cell passed through.

[hawkeye_wx]

2 minutes ago, Natester said:

Just had some half-inch hail as the cell passed through.

The hail core passed barely southeast of my house, so I only got pea size (maybe a few a bit larger).

[hawkeye_wx]

1.50" hail report from Cedar Rapids.  I got lucky.

Update:  Now a 1.75" (golfball) report from Marion (ne edge of Cedar Rapids)

[Witness Protection Program]

3 hours ago, A-L-E-K said:

hoping 4 more sick footage today

Like barfing or sneezing or what?  Spoiler tag those vids, please.

[RCNYILWX]

The 12z NSSL-WRF has a supercell latched on the warm front right into the Chicago metro this evening. 12z NAMnest finally showing storms into the CWA this evening.

Regarding tomorrow, unclear if a remnant QLCS/MCS moves across in the early morning, though timing wise and conceptually, redevelopment in late morning over the area would certainly be more concerning for higher end severe over parts of the LOT CWA. A weakening MCS preceding redevelopment could put some leftover OFBs in play, with respect to the tornado threat.

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