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July 21-? Severe Weather


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I'm not so sure about that...SBCINH is only about -25J/kg and that's not enough to totally preclude that this could be sfc-based...could it be elevated? Maybe, but I wouldn't bet on it.

It's hard to tell - the only forcing mechanism at this point appears to be a line of sfc-based frontagenesis along the WI/IL boarder, and it's possible that this is sufficient forcing to overcome CINH. Remember though, -25 J/Kg ~= 7 m/s VV minimum required to overcome negative buoyancy, with is hard to achieve without convective ascent. Could be that SFC frontagentic lift has eroded the cap beyond what is indicated by mesoanalysis.

The fact that even some of the smaller cell motions are in more accordance with low-mid level flow would suggest elevated base as well.

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It's hard to tell - the only forcing mechanism at this point appears to be a line of sfc-based frontagenesis along the WI/IL boarder, and it's possible that this is sufficient forcing to overcome CINH. Remember though, -25 J/Kg ~= 7 m/s VV minimum required to overcome negative buoyancy, with is hard to achieve without convective ascent. Could be that SFC frontagentic lift has eroded the cap beyond what is indicated by mesoanalysis.

Do you live in the Milwaukee area? Your current conditions icon caught my eye, given that it was Milwaukee's current conditions.

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MESOSCALE DISCUSSION 1767

NWS STORM PREDICTION CENTER NORMAN OK

0654 PM CDT WED JUL 27 2011

AREAS AFFECTED...NRN IL...FAR SRN WI...E-CNTRL IA

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE

VALID 272354Z - 280100Z

CONVECTIVE TRENDS ARE BEING MONITORED FOR A POSSIBLE WW...WITH A

PRIMARY THREAT OF DMGG WINDS AND LARGE HAIL...AND PERHAPS AN

ISOLATED TORNADO.

CLUSTER OF STORMS HAS INTENSIFIED IN THE PAST HR NEAR KDBQ ALONG A

SLOW-MOVING WARM FRONT AS A REMNANT MCV SHIFTS EWD ACROSS LAKE

MICHIGAN. AREAL COVERAGE HAS PROBABLY BEEN LIMITED THUS FAR BY

SHORTWAVE UPPER RIDGING OVERHEAD AND WARM MIDLEVEL TEMPERATURES.

HOWEVER...PWAT VALUES IN EXCESS OF 2 INCHES /PER 00Z GPS-IPW DATA/

AND VERY RICH BOUNDARY LAYER MOISTURE IN PLACE HAS AIDED IN EXTREME

INSTABILITY WITH MLCAPE VALUES APPROACHING 4000 J/KG...AND SHOULD

SUPPORT FURTHER CONVECTIVE DEVELOPMENT/MAINTENANCE THROUGH THE NEXT

SEVERAL HRS. ALTHOUGH CONVECTIVE EVOLUTION IS SOMEWHAT UNCERTAIN DUE

TO SUBTLE FORCING MECHANISMS IN PLACE...MODERATELY STRONG MIDLEVEL

FLOW /E.G. 40 KTS AT 500 MB/ ALONG WITH VEERING LOW-LEVEL WIND

PROFILES COULD SUPPORT AN ORGANIZED SVR THREAT ACROSS NRN IL SHOULD

CONVECTIVE TRENDS CONTINUE TO INCREASE. PRIMARY THREATS ATTM APPEAR

TO BE LARGE HAIL AND DMGG WINDS...THOUGH AN ISOLATED TORNADO CANNOT

BE RULED OUT.

..ROGERS.. 07/27/2011

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Yes :), do you?

Yes. I live very close to the geometric center of the county, and have been waiting for a decent rain event to come along. This still appears, though, like last week, to focus just south of the area, and I ruled out severe late this afternoon when the sun failed to even peek through.

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BULLETIN - EAS ACTIVATION REQUESTED

TORNADO WARNING

NATIONAL WEATHER SERVICE QUAD CITIES IA IL

735 PM CDT WED JUL 27 2011

THE NATIONAL WEATHER SERVICE IN THE QUAD CITIES HAS ISSUED A

* TORNADO WARNING FOR...

NORTH CENTRAL JACKSON COUNTY IN EAST CENTRAL IOWA...

SOUTHEASTERN DUBUQUE COUNTY IN NORTHEAST IOWA...

JO DAVIESS COUNTY IN NORTHWEST ILLINOIS...

* UNTIL 815 PM CDT.

* AT 728 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED

A POSSIBLE TORNADO NEAR DUBUQUE REGIONAL AIRPORT...OR 8 MILES

SOUTH OF DUBUQUE...MOVING EAST AT 25 MPH. ANOTHER STORM WITH A

POSSIBLE TORNADO IS 5 MILES SOUTHEAST OF GALENA...ALSO MOVING EAST

AT 25 MPH.

* THE TORNADO WILL BE NEAR...

MASSEY AROUND 740 PM CDT...

ST. DONATUS AROUND 745 PM CDT...

GALENA...AIKEN...RICE AND SMITHS THROUGH 800 PM CDT...

GALENA TERRITORY AND RODDEN THROUGH 810 PM

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This is not going to end well. Rain wrapped intense mesos in an environment that frankly supports strong tornadoes.

And hilly terrain that doesn't support visuals either.

65 dBZ to over 44kft (extremely large hail possible) and a tight mid level meso that has maintained continuity from scan to scan now.

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Rockford over towards Chicago are definitely looking good for a significant severe threat this evening.

Not good, especially considering the Jo Daviess cell is on line to hit Northern Lake County which got the worst of the rains this morning, up to 5 inches I believe. A repeat in the same day along with severe weather ain't gonna be pretty up in northern Lake.

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0-1 km shear north of 20 knots, ample 0-3 km CAPE (150+) and plenty of vorticity along the effective warm front. Might see a couple short but intense low level circulations out of this.

completely agree with this post and yours before this one, this image says it all, 3 strong low level circuations..

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