More severe weather - July 19-20, Severe damage in St. Louis

[CrazyC83]

Slight risk with possible upgrade to moderate for tomorrow (currently 30-hatched) over parts of Minnesota and Wisconsin. Tornado threat significant as well as a derecho threat.

...NRN PLAINS/UPPER MS VALLEY INTO THE UPPER GREAT LAKES...
THERMODYNAMIC ENVIRONMENT WILL BE INCREASINGLY FAVORABLE FOR
STRONG/SEVERE CONVECTION AS LOW LEVEL MOISTURE RETURNS NWD BENEATH
PRE-EXISTING PLUME OF STEEP MID LEVEL LAPSE RATES ASSOCIATED WITH
THE ELEVATED MIXED LAYER FROM THE NRN PLAINS ACROSS THE UPPER MS
VALLEY. ELEVATED THUNDERSTORMS MAY BE OCCURRING IN THE MORNING
ACROSS PARTS OF THE DAKOTAS WITH STRONGER STORMS CAPABLE OF
PRODUCING ISOLATED HAIL AND STRONG WIND GUSTS. PRIMARY SEVERE
THREAT IS EXPECTED TO DEVELOP DURING THE AFTERNOON AND EVENING AS
THE ELEVATED CONVECTION SPREADS EWD TOWARD THE FRONTAL ZONE WITH
POTENTIAL TO BECOME ROOTED IN THE BOUNDARY LAYER...AND ADDITIONAL
STORMS ARE LIKELY TO DEVELOP ALONG/JUST AHEAD OF THE FRONT AS LOW
LEVEL CONVERGENCE AND STRONG HEATING LOCALLY WEAKENS THE CAP.

ENVIRONMENT IS FORECAST TO BECOME VERY UNSTABLE NEAR THE FRONT AS
SURFACE TEMPERATURES WARM INTO THE 90S AND DEW POINTS INCREASE INTO
THE 70S...CONTRIBUTING TO MLCAPE OF 2500-4000 J/KG. VERTICAL SHEAR
IS ALSO EXPECTED TO STRENGTHEN AS FORECAST SOUNDINGS EXHIBIT WIND
PROFILES THAT VEER AND INCREASE WITH HEIGHT...IN RESPONSE TO A 50-60
KT MID LEVEL JET STREAK MOVING ACROSS ND INTO MN ON THE SOUTH SIDE
OF THE SHORT WAVE TROUGH. COMBINATION OF STRONG INSTABILITY AND
MODERATE DEEP LAYER SHEAR INDICATES POTENTIAL FOR A FEW SUPERCELLS
TO DEVELOP...PRIMARILY FROM ERN SD INTO CENTRAL/SRN MN DURING THE
AFTERNOON SPREADING EWD INTO PARTS OF WI AT NIGHT. STEEP LAPSE
RATES/LARGE INSTABILITY AND A FAVORABLY SHEARED ENVIRONMENT SUGGEST
STRONGER STORMS WILL BE CAPABLE OF PRODUCING VERY LARGE
HAIL...DAMAGING WIND GUSTS...AND A FEW TORNADOES. THE TORNADO
THREAT WILL BE ENHANCED IF DISCRETE CELLS CAN BE MAINTAINED INTO THE
EVENING HOURS. CONVECTION IS EXPECTED TO GROW UPSCALE INTO ONE OR
MORE MCS/S DURING THE OVERNIGHT HOURS WITH SEVERE THREAT CONTINUING
AFTER DARK TOWARD THE UPPER GREAT LAKES. UNCERTAINTY IN CONVECTIVE
MODE PRECLUDES INTRODUCTION OF A HIGHER RISK CATEGORY ATTM BUT
REGION WILL BE MONITORED FOR POSSIBLE UPGRADE IN LATER OUTLOOKS.

I'm leaning to a similar setup as yesterday's system in northeastern Ontario. It could be severe!

[CrazyC83]

SPC has indeed gone to a Moderate Risk for southern Minnesota and Wisconsin.

I'll be south of the peak risk this time, but some of those areas in the maximum threat this time got considerable damage on Monday too...

Here we go again!

[CrazyC83]

SEL6

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 616
NWS STORM PREDICTION CENTER NORMAN OK
1000 AM CDT WED JUL 19 2006

THE NWS STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

NORTHEAST IOWA
SOUTHEAST MINNESOTA
SOUTHWEST WISCONSIN

EFFECTIVE THIS WEDNESDAY MORNING AND AFTERNOON FROM 1000 AM UNTIL
300 PM CDT.

HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70
MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 60
STATUTE MILES NORTH AND SOUTH OF A LINE FROM 30 MILES WEST
NORTHWEST OF ROCHESTER MINNESOTA TO 25 MILES SOUTH OF CAMP
DOUGLAS WISCONSIN. FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU6).

REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE
FAVORABLE FOR SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH
AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR
THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS
AND POSSIBLE WARNINGS. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY
DO PRODUCE TORNADOES.

DISCUSSION...ELEVATED MCS OVER SRN MN MAY BE TRANSITION TO MORE
SURFACE-BASED CONVECTION AS THE LOW LEVELS MOISTEN/DESTABILIZE
ACROSS SE MN/SW WI. RECENT RADAR IMAGERY SUGGESTS THE DEVELOPMENT OF
A BOW ECHO AND ACCELERATION OF THE CONVECTIVE LINE TO NEAR 50
KT...THUS THE THREAT FOR DAMAGING WINDS SHOULD BE INCREASING ACROSS
SE MN/SW WI AND PERHAPS NE IA THE NEXT FEW HOURS.

AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60
KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM
MOTION VECTOR 28045.


...THOMPSON


Note: The parallelogram is only an approximation to the watch, the actual watch is defined by the outlines of the counties contained in it.

SEL6

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 616
NWS STORM PREDICTION CENTER NORMAN OK
1000 AM CDT WED JUL 19 2006

THE NWS STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

NORTHEAST IOWA
SOUTHEAST MINNESOTA
SOUTHWEST WISCONSIN

EFFECTIVE THIS WEDNESDAY MORNING AND AFTERNOON FROM 1000 AM UNTIL
300 PM CDT.

HAIL TO 2 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70
MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 60
STATUTE MILES NORTH AND SOUTH OF A LINE FROM 30 MILES WEST
NORTHWEST OF ROCHESTER MINNESOTA TO 25 MILES SOUTH OF CAMP
DOUGLAS WISCONSIN. FOR A COMPLETE DEPICTION OF THE WATCH SEE THE
ASSOCIATED WATCH OUTLINE UPDATE (WOUS64 KWNS WOU6).

REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE
FAVORABLE FOR SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH
AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR
THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS
AND POSSIBLE WARNINGS. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY
DO PRODUCE TORNADOES.

DISCUSSION...ELEVATED MCS OVER SRN MN MAY BE TRANSITION TO MORE
SURFACE-BASED CONVECTION AS THE LOW LEVELS MOISTEN/DESTABILIZE
ACROSS SE MN/SW WI. RECENT RADAR IMAGERY SUGGESTS THE DEVELOPMENT OF
A BOW ECHO AND ACCELERATION OF THE CONVECTIVE LINE TO NEAR 50
KT...THUS THE THREAT FOR DAMAGING WINDS SHOULD BE INCREASING ACROSS
SE MN/SW WI AND PERHAPS NE IA THE NEXT FEW HOURS.

AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 2 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60
KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM
MOTION VECTOR 28045.


...THOMPSON


Note: The parallelogram is only an approximation to the watch, the actual watch is defined by the outlines of the counties contained in it.
Note: Click for Watch Status Reports.

WOUS64 KWNS 191457
WOU6

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH OUTLINE UPDATE FOR WS 616
NWS STORM PREDICTION CENTER NORMAN OK
1000 AM CDT WED JUL 19 2006

SEVERE THUNDERSTORM WATCH 616 IS IN EFFECT UNTIL 300 PM CDT
FOR THE FOLLOWING LOCATIONS

IAC005-037-043-065-067-089-131-191-192000-
/O.NEW.KWNS.SV.A.0616.060719T1500Z-060719T2000Z/

IA
. IOWA COUNTIES INCLUDED ARE

ALLAMAKEE CHICKASAW CLAYTON
FAYETTE FLOYD HOWARD
MITCHELL WINNESHIEK


MNC039-045-047-049-055-099-109-147-157-169-192000-
/O.NEW.KWNS.SV.A.0616.060719T1500Z-060719T2000Z/

MN
. MINNESOTA COUNTIES INCLUDED ARE

DODGE FILLMORE FREEBORN
GOODHUE HOUSTON MOWER
OLMSTED STEELE WABASHA
WINONA


WIC001-011-023-043-053-057-063-081-091-093-103-121-123-192000-
/O.NEW.KWNS.SV.A.0616.060719T1500Z-060719T2000Z/

WI
. WISCONSIN COUNTIES INCLUDED ARE

ADAMS BUFFALO CRAWFORD
GRANT JACKSON JUNEAU
LA CROSSE MONROE PEPIN
PIERCE RICHLAND TREMPEALEAU
VERNON


ATTN...WFO...ARX...MPX...





Note: The Aviation Watch (SAW) product is an approximation to the watch area. The actual watch is defined by the list of counties (WOU).

SAW6
WW 616 SEVERE TSTM IA MN WI 191500Z - 192000Z
AXIS..60 STATUTE MILES NORTH AND SOUTH OF LINE..
30WNW RST/ROCHESTER MN/ - 25S VOK/CAMP DOUGLAS WI/
..AVIATION COORDS.. 50NM N/S /48S MSP - 22W DLL/
HAIL SURFACE AND ALOFT..2 INCHES. WIND GUSTS..60 KNOTS.
MAX TOPS TO 500. MEAN STORM MOTION VECTOR 28045.

LAT...LON 44959305 44439026 42709026 43229305

THIS IS AN APPROXIMATION TO THE WATCH AREA. FOR A
COMPLETE DEPICTION OF THE WATCH SEE WOUS64 KWNS
FOR WOU6.


Watch 616 Status Report Message has not been issued yet.

[WindRunner]

A little early in the day for WWs . . . guess this means things are going to get interesting . . .

[CrazyC83]

I think so too. They extended the MDT eastward, and I wouldn't be shocked to see them go HIGH (upgrade the wind to 60-hatched) later...

Looks like they are trying to be harsher after two underestimations in a row (both of the last two days should have been a moderate risk IMO)...

[WindRunner]

Wow . . . 60? Haven't seen that in a while . . .

Right now sitting at a 45-hatched for wind and a 10 for the tornadoes - not too common for this time of year . . . amazing that there aren't any warnings out right now though. Looks like a decaying bow echo on radar from Quad Cities, and some sort of squall line forming up out of the middle of it, kind of like some sort of feederband or something. It should have a watch up sometime soon, like the MD says.

Very intense lightning with these storms, however. I almost can't see the radar through the lightning . . .

[CrazyC83]

Right now, the CAPE values are incredibly high in some areas.

The only thing preventing a monster outbreak, a la April 2, is the cap which is holding up.

I wouldn't be surprised to see PDS watches come up soon...in addition to the possible High Risk.

From easternuswx: Amazing svr parameters over Iowa in vicinity of Des Moines at 19z.
MU CAPE 8000, Craven sig svr. 140, Supercell 48, Sig Hail 6 , LI -14, Tor 3, EHI 11

[wxmann_91]

Right now, the CAPE values are incredibly high in some areas.

The only thing preventing a monster outbreak, a la April 2, is the cap which is holding up.

I wouldn't be surprised to see PDS watches come up soon...in addition to the possible High Risk.

From easternuswx: Amazing svr parameters over Iowa in vicinity of Des Moines at 19z.
MU CAPE 8000, Craven sig svr. 140, Supercell 48, Sig Hail 6 , LI -14, Tor 3, EHI 11

Yeah, the parameters are just incredible, backed winds, outbreak IF IT WERE NOT for the CINH which is preventing sfc-based convection from developing. I don't think this warrants PDS watches since that variable will continue to be a factor throughout the rest of today and tonight. Even if the CINH can break, LCL heights are still a bit high in the unstable sector due to stronger mixing, and the shear is unjuxtaposed, too far to the north, as a result of the elevated convection in MN blocking the northward progression of the warm front.

[CrazyC83]

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 620
NWS STORM PREDICTION CENTER NORMAN OK
350 PM CDT WED JUL 19 2006

THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF

NORTH CENTRAL AND NORTHWEST IOWA
EXTREME NORTHEAST NEBRASKA
EXTREME SOUTHEAST SOUTH DAKOTA

EFFECTIVE THIS WEDNESDAY AFTERNOON AND EVENING FROM 350 PM UNTIL
1100 PM CDT.

TORNADOES...HAIL TO 3 INCHES IN DIAMETER...THUNDERSTORM WIND
GUSTS TO 80 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE
AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 45 STATUTE
MILES NORTH AND SOUTH OF A LINE FROM 45 MILES NORTHWEST OF SIOUX
CITY IOWA TO 35 MILES SOUTH OF MASON CITY IOWA. FOR A COMPLETE
DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE UPDATE
(WOUS64 KWNS WOU0).

REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH
AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR
THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS
AND POSSIBLE WARNINGS.

OTHER WATCH INFORMATION...CONTINUE...WW 617...WW 618...WW 619...

DISCUSSION...AN OUTFLOW BOUNDARY FROM MORNING CONVECTION HAS STALLED
ACROSS NW IA...WHILE A REINFORCING SURGE PUSHES WWD ACROSS CENTRAL
IA FROM THE ONGOING IL MCS. ALONG AND S/W OF THESE OUTFLOWS...THE
LOW LEVELS HAVE BECOME QUITE MOIST AND UNSTABLE...WITH MLCAPE VALUES
NOW EXCEEDING 4000 J/KG. FARTHER W...STRONG SURFACE HEATING HAS
ERODED THE CAP AND BOUNDARY LAYER CUMULUS ARE DEVELOPING ENEWD
ACROSS NE NEB. PRESENT INDICATIONS ARE THAT THUNDERSTORM INITIATION
WILL OCCUR BY ROUGHLY 22-23Z NEAR THE INTERSECTION OF
IA/NEB/SD...WITH RAPID INTENSIFICATION OF THE STORMS EXPECTED. THE
EXTREME INSTABILITY...ALONG WITH EFFECTIVE BULK SHEAR IN EXCESS OF
40 KT AND 0-1 KM SRH IN EXCESS OF 150 M2/S2 ALONG THE OUTFLOW
BOUNDARY...WILL SUPPORT INTENSE SUPERCELLS CAPABLE OF PRODUCING VERY
LARGE HAIL AND A FEW TORNADOES. CONVECTION MAY EVENTUALLY GROW
UPSCALE INTO AN MCS ACROSS IA BY EARLY TONIGHT...WITH AN INCREASING
THREAT FOR DAMAGING WINDS.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 3 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 70 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
600. MEAN STORM MOTION VECTOR 29025.

[all_we_know_is_FALLING]

Right now, the CAPE values are incredibly high in some areas.

The only thing preventing a monster outbreak, a la April 2, is the cap which is holding up.

I wouldn't be surprised to see PDS watches come up soon...in addition to the possible High Risk.

From easternuswx: Amazing svr parameters over Iowa in vicinity of Des Moines at 19z.
MU CAPE 8000, Craven sig svr. 140, Supercell 48, Sig Hail 6 , LI -14, Tor 3, EHI 11

On April 2, there wasn't a high risk or a PDS watch up for the areas hardest hit. And they were just south of the moderate risk area too.

[CrazyC83]

Right now, the CAPE values are incredibly high in some areas.

The only thing preventing a monster outbreak, a la April 2, is the cap which is holding up.

I wouldn't be surprised to see PDS watches come up soon...in addition to the possible High Risk.

From easternuswx: Amazing svr parameters over Iowa in vicinity of Des Moines at 19z.
MU CAPE 8000, Craven sig svr. 140, Supercell 48, Sig Hail 6 , LI -14, Tor 3, EHI 11

On April 2, there wasn't a high risk or a PDS watch up for the areas hardest hit. And they were just south of the moderate risk area too.

Very true. That is what could very well repeat itself here...the storms are firing up over Nebraska but still have to enter a much more favorable environment...

[Gorky]

The few storms cropping up in Nebraska are showing tops to 62.5K feet according to grlevel3... Gives you an idea of the potential really, when that isn't the area of highest instability

[conestogo_flood]

What is happening? Something big is brewing?

[Gorky]

If the cap breaks, then yes... Currently up to 9000 Cape in places, Li's of -14, Craven Sig Svr at almost 200. There is a hell of a lot of instability waiting to be tapped into if the cap gives way.There are a few storms firing in Nebraska, but it is in Iowa where the worst will be if the cap can break. Thats a big IF though It's struggling at the moment...

[conestogo_flood]

9000 kg? What?!

[WindRunner]

Strong bow echo/possible derecho starting to effect St. Louis - 3 seperate METAR stations reporting gusts to 48, 55, and 63 mph. That's KSET, KSTL, and KALN respectively.

EDIT: Missed a couple . . . KSUS gusting to 51 and KCPS to 59. Both of those obs were made a full 7 miles ahead of the leading edge of precip.

[badger70]

Trained spotter confirms 'nado in south St. Louis (EDIT: Near Jefferson Barracks)

Streaming coverage at
http://kmov.com KMOV-TV - St. Louis

[Bunkertor]

Is internet explorer needed ?

[badger70]

Is internet explorer needed ?

Nope. I'm seeing it with Linux/firefox with mplayer plugin for Windows media.

EDIT: The direct url is http://www.kmov.com//sharedcontent/Vide ... 0&live=yes

[TexasStooge]

Is internet explorer needed ?

Not necessarily, although it requires windows media player.