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June 22-23 Severe Weather Outbreak


Stebo

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Looking at 00Z Observed soundings from KDVN, KGRB, and KAPX seems like a significant amount of moistening will need to occur for us to get anywhere close to the environment advertised for tomorrow. Sounding at KDVN at 00Z depicted a  pretty impressive dewpoint of 68, however upon further examination there is a very shallow layer of boundary layer moisture extending only to about 950mb. Soundings to the South/southwest across NE KS/ SW MO at KTOP and KSGF depict a very moist boundary layer with SFC dp's  70-75F, i'm assuming this will likely advect NE into the main area overnight and in the morning due to strong WAA... However further north at KGRB there was a SFC DP of 58, but with a much deeper layer of moisture extending to about 800mb or so, and a very similar sounding at least as far as moisture goes at KAPX with a DP of 58 and a moist layer to about 800mb... Anyways have some doubt about the northward extent of greater moisture into areas like GRB/APX due to the possibility of quite a large MCS moving through and south of the area, likely leaving behind residual cloud cover, and scouring out moisture out of at least N/C WI and MI, which would basically wipe away the entire northern half of the threat area. Thoughts? For those, like my self who have been looking at the NAM, you'll see that it initialized with a SFC DP at ~65 at GRB on the 00Z run, and has forecasted 65-70 SFC DP's at both GRB and APX as well as a very deep moist layer... Any thoughts? and please correct me if i'm wrong since I very well could/ will be. 

I was thinking that the whole day... the northern (and possibly central) Wisconsin might not get anywhere near the instability that is advertised by the models

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I would be floored if part of the Enhanced isn't upgraded at 06z. Honestly if convective mode is realized and things unfold like the NAM/4kmNAM there is a possibility they even up to a High. Also if the MCS happens to go nuts tonight and looks to turn into a derecho they could go High at some point for wind. Needless to say, I don't expect the day 1 to be an enhanced risk only.

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I would be floored if part of the Enhanced isn't upgraded at 06z. Honestly if convective mode is realized and things unfold like the NAM/4kmNAM there is a possibility they even up to a High. Also if the MCS happens to go nuts tonight and looks to turn into a derecho they could go High at some point for wind. Needless to say, I don't expect the day 1 to be an enhanced risk only.

 

 

I think if tonight's convective allowing models are all over the place for tomorrow, then maybe it stays at enhanced initially, but I'm leaning toward a moderate on the 6z outlook.

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I would be floored if part of the Enhanced isn't upgraded at 06z. Honestly if convective mode is realized and things unfold like the NAM/4kmNAM there is a possibility they even up to a High. Also if the MCS happens to go nuts tonight and looks to turn into a derecho they could go High at some point for wind. Needless to say, I don't expect the day 1 to be an enhanced risk only.

 

I don't think it's a question of "if" as far as an upgrade from enhanced, just when and where...

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That sounding is absolutely frightening.  I have to assume that these parameters are greater than what was prevalent for the April 9 Rochelle EF-4.  And the moderate risk issued then for nw IL after cycles of enhanced risk outlooks was for a much smaller geographical area than what we will see Monday.

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If it were me, I'd put the hatched tornado area in eastern WI/northeast IL/northern IN and over into Michigan.  How much of Michigan is a bit tricky.

M-46 and south to I-94 as far east as US-23 or I-75.

 

Btw Powerball mentioned the 12km NAM showing convection on the warm front in MI. If that were to occur it would be in a very volatile atmosphere especially if the MCS goes through central and northern Michigan, that would only enhance the warm front and locally increase an already highly sheared atmosphere.

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That sounding is absolutely frightening.  I have to assume that these parameters are greater than what was prevalent for the April 9 Rochelle EF-4.  And the moderate risk issued then for nw IL after cycles of enhanced risk outlooks was for a much smaller geographical area than what we will see Monday.

 

mhL9khC.png

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FWIW 00Z GFS shows a large MCS barreling into S WI/ N IL at 15-18Z tomorrow... And then more development along the along the CF later.. Huge QPF bomb. And the 01Z and 02Z HRRR shows a similar scenario, just a tad further south with development.

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Looks like its coming down to which model solutions you prefer... And if you believe the WAA will fuel the MCS, and if the MCS will be in N WI or S WI... OR if the EMl/cap will kill the MCS before it ruins anything. Lots of uncertainty regarding the MCS... IF it is ongoing and doesn't die, it'll likely be the big show and possibly be a destructive bow-echo, maybe even a derecho... But if its not and it dissipates or moves more so north than shown by the HRRR/GFS, etc... then we will likely see a significant severe/tornado threat across a wide area during the afternoon and into the night as shown by the 4KM NAM.

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Looks like its coming down to which model solutions you prefer... And if you believe the WAA will fuel the MCS, and if the MCS will be in N WI or S WI... OR if the EMl/cap will kill the MCS before it ruins anything. Lots of uncertainty regarding the MCS... IF it is ongoing and doesn't it'll likely be the big show and possibly be a destructive bow-echo, maybe even a derecho... But if its not and it dissipates or moves more so north than shown by the HRRR/GFS, etc... then we will likely see a significant severe/tornado threat across a wide area as shown by the 4KM NAM.

Ok but the thing we have to realize is either way we're looking a significant event, wether the derecho/MCS dissipates or not. I confidently think this warrants AT LEAST a moderate risk.

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FWIW 00Z GFS shows a large MCS barreling into S WI/ N IL at 15-18Z tomorrow... And then more development along the along the CF later.. Huge QPF bomb. And the 02Z HRRR shows a similar scenario, just a tad further south with development.

The problem with the GFS scenario is there is one lone supercell in SD right now and it is weakening, the GFS blows that up into the main MCS. Where as currently the main MCS looks to be in ND and the GFS takes that toward Duluth before dying.

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Alrighty, time for me to voice my thoughts....

 

All I can say is, wow. Tomorrow, somewhere, if not in my back yard, will get rocked, just like Rochelle and Fairdale did. I expect it to be bad, if everything crumbles into place.... I will have to keep watching throughout the day, and eventually get ready to start storm spotting when the big stuff shows up, be it morning or afternoon... And, reporting in damage from our fire department. 

 

I am going to glue myself to this topic, it for sure warrants  a watchin. 

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The problem with the GFS scenario is there is one lone supercell in SD right now and it is weakening, the GFS blows that up into the main MCS. Where as currently the main MCS looks to be in ND and the GFS takes that toward Duluth before dying.

The main MCS for areas further south will likely come from the activity currently in SW. ND/NW. SD/SE. MT/NE. WY.
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The main MCS for areas further south will likely come from the activity currently in SW. ND/NW. SD/SE. MT/NE. WY.

Exactly what I was about to say. Practically all-- if not all-- models have that activity blowing up into the main MCS that will propagate E/SE. GFS has generally a similar solution to most models with a larger and stronger MCS developing over-night/this morning over NC/C SD.  

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NWS IWX's current thinking is everything will die before making it to our area.

 

Huh?

 

http://forecast.weather.gov/product.php?site=IWX&issuedby=IWX&product=AFD&format=CI&version=1&glossary=1

 

000

FXUS63 KIWX 212348

AFDIWX

AREA FORECAST DISCUSSION

NATIONAL WEATHER SERVICE NORTHERN INDIANA

 

.SHORT TERM...(THIS EVENING THROUGH MONDAY)

ISSUED AT 539 PM EDT SUN JUN 21 2015

 

PRIMARY FOCUS ON POTNL SEVERE WITH EVEN EXTREME DAMAGING WIND POTNL

WITH WELL DEVELOPED QLCS PUSHING THROUGH CWA EARLY MONDAY NIGHT. IN

NEAR TERM HAVE SQUELCHED POPS OVERNIGHT. UPSTREAM FOCUS ALONG SLOWLY

NEWD RETREATING WARM FNTL BNDRY INVOF I70 SHOWING DEFICIENCY IN

UPWIND SUSTAINENCE. WITH REFOCUS OF LOW LEVEL JET FARTHER WWD WITH

TIME OVERNIGHT...INCREASING BLCIN AND WNW STEERING FLOW ANTICIPATE

LITTLE CHC FOR CONVECTION ACRS CWA OVERNIGHT...ESPCLY GIVEN TOTALITY

OF SWD COMPOSITE OUTFLOW FROM LAST NIGHTS CONVECTION. ATTENTION

TURNS TO POTNL FOR XTRM DESTABILIZATION ACRS SWRN GRTLKS ON ORDER OF

4500-5500 J/KG BY LATE AFTN IN AXIS SERN WI TO SRN IA/NWRN MO AND

LESSER SECONDARY AXIS ACRS NERN IL MOVG THROUGH NWRN CWA...WHERE

ISOLD SUPERCELLS AHEAD OF PRIMARY AXIS MAY FORM AMID 50KTS DEEP

LAYER SHEAR WITH LARGE SWEEPING HELICAL HODOS...AS HIGHLY RAMPED

WESTERLIES ON ORDER OF 70-85KTS INTO WESTERN LWR MI. STRONG UPDRAFT

ROTATION/0-1KM HELICITY COULD ALSO BE ENHANCED SHOULD COOLER LAKE

ENVIRONMENT SLOW NWD PUSH OF SFC WARM FNTL BNDRY/LAKE ENHANCED

TRIPLE POINT. IN 00 UTC TO 06 UTC TIMEFRAME PRIMARY WELL DEVELOPED

QLCS EXPECTED TO SWEEP THROUGH CWA. STRONG WIND PROFILES/STORM

MOTION WITH PREFERRED DEEP LYR SHEAR/STORM MOTION VECTORING FOSTERING

GOOD COLD POOL BALANCE.

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Huh?

 

http://forecast.weather.gov/product.php?site=IWX&issuedby=IWX&product=AFD&format=CI&version=1&glossary=1

 

000

FXUS63 KIWX 212348

AFDIWX

AREA FORECAST DISCUSSION

NATIONAL WEATHER SERVICE NORTHERN INDIANA

 

.SHORT TERM...(THIS EVENING THROUGH MONDAY)

ISSUED AT 539 PM EDT SUN JUN 21 2015

 

PRIMARY FOCUS ON POTNL SEVERE WITH EVEN EXTREME DAMAGING WIND POTNL

WITH WELL DEVELOPED QLCS PUSHING THROUGH CWA EARLY MONDAY NIGHT. IN

NEAR TERM HAVE SQUELCHED POPS OVERNIGHT. UPSTREAM FOCUS ALONG SLOWLY

NEWD RETREATING WARM FNTL BNDRY INVOF I70 SHOWING DEFICIENCY IN

UPWIND SUSTAINENCE. WITH REFOCUS OF LOW LEVEL JET FARTHER WWD WITH

TIME OVERNIGHT...INCREASING BLCIN AND WNW STEERING FLOW ANTICIPATE

LITTLE CHC FOR CONVECTION ACRS CWA OVERNIGHT...ESPCLY GIVEN TOTALITY

OF SWD COMPOSITE OUTFLOW FROM LAST NIGHTS CONVECTION. ATTENTION

TURNS TO POTNL FOR XTRM DESTABILIZATION ACRS SWRN GRTLKS ON ORDER OF

4500-5500 J/KG BY LATE AFTN IN AXIS SERN WI TO SRN IA/NWRN MO AND

LESSER SECONDARY AXIS ACRS NERN IL MOVG THROUGH NWRN CWA...WHERE

ISOLD SUPERCELLS AHEAD OF PRIMARY AXIS MAY FORM AMID 50KTS DEEP

LAYER SHEAR WITH LARGE SWEEPING HELICAL HODOS...AS HIGHLY RAMPED

WESTERLIES ON ORDER OF 70-85KTS INTO WESTERN LWR MI. STRONG UPDRAFT

ROTATION/0-1KM HELICITY COULD ALSO BE ENHANCED SHOULD COOLER LAKE

ENVIRONMENT SLOW NWD PUSH OF SFC WARM FNTL BNDRY/LAKE ENHANCED

TRIPLE POINT. IN 00 UTC TO 06 UTC TIMEFRAME PRIMARY WELL DEVELOPED

QLCS EXPECTED TO SWEEP THROUGH CWA. STRONG WIND PROFILES/STORM

MOTION WITH PREFERRED DEEP LYR SHEAR/STORM MOTION VECTORING FOSTERING

GOOD COLD POOL BALANCE.

 

I meant the MCS'es out in the Plains, per there grids

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IT's been consistently showing a "different" solution here, already building 1500 to 2000 J/KG of CAPE by 15z tomorrow with mostly clear skies through 18z.

Admittedly i was looking imby at a couple large discretes...

Clear skies through 18z for you would be change compared to the last month for you guys...and on such a potentially explosive day to boot

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Admittedly i was looking imby at a couple large discretes...

Clear skies through 18z for you would be change compared to the last month for you guys...and on such a potentially explosive day to boot

 

Yep.

 

And having those CAPE values so early in the day would certainly help with any potential initiation along the warm front (assuming no issues from the Plains MCS). The other models don't advect those values in until after 21z.

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4K NAM is questionable as well with its moisture forecast... across WI and IL it has DP's from the lower 50's across NC/C WI to mid 60's south of there at 12Z. Then at 15Z it shoots DP's to the upper 60's lower 70's across NC/C WI all with some convection over N IL/IA at the time, a significant increase by about 8-10 degrees in 3 hours... Thats either erroneous, or some pretty intense WAA.  

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4K NAM is questionable as well with its moisture forecast... across WI and IL it has DP's from the lower 50's across NC/C WI to mid 60's south of there at 12Z. Then at 15Z it shoots DP's to the upper 60's lower 70's across NC/C WI all with some convection over N IL/IA at the time, a significant increase by about 8-10 degrees in 3 hours... Thats either erroneous, or some pretty intense WAA.  

 

Um, are you not seeing the strength of the low level winds tomorrow?

 

Moisture surges like that are very common in these types of events.

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