General Elsewhere Weather

multimedia briefing online:

Looks like a high risk will be issued.

Wow. That will be something else to watch on GR3...and it'll be affecting a highly populated area.

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 298
NWS STORM PREDICTION CENTER NORMAN OK
150 PM CDT WED JUN 12 2013

THE NWS STORM PREDICTION CENTER HAS ISSUED A

* TORNADO WATCH FOR PORTIONS OF
NORTHEAST IOWA
NORTHERN ILLINOIS
EXTREME SOUTHEAST MINNESOTA
SOUTHWEST WISCONSIN

* EFFECTIVE THIS WEDNESDAY AFTERNOON AND EVENING FROM 150 PM
UNTIL 900 PM CDT.

...THIS IS A PARTICULARLY DANGEROUS SITUATION...

* PRIMARY THREATS INCLUDE...
SEVERAL INTENSE TORNADOES LIKELY
SEVERAL SIGNIFICANT DAMAGING WIND GUSTS TO 80 MPH POSSIBLE
SEVERAL VERY LARGE HAIL EVENTS TO 3 INCHES IN DIAMETER POSSIBLE

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 65 STATUTE
MILES EITHER SIDE OF A LINE FROM 35 MILES WEST SOUTHWEST OF MASON
CITY IOWA TO 20 MILES EAST SOUTHEAST OF ROCKFORD ILLINOIS. FOR A
COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE
UPDATE (WOUS64 KWNS WOU8).

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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.

&&

DISCUSSION...POTENTIALLY EXPLOSIVE THUNDERSTORM DEVELOPMENT IS
POSSIBLE OVER THE NEXT FEW HOURS AS GRADUALLY DEEPENING SURFACE LOW
TRACKS EAST ALONG A FRONTAL ZONE SITUATED FROM NORTHEAST IOWA
EASTWARD ALONG THE WI/IL BORDER TO LAKE MICHIGAN. A VOLATILE WARM
AND VERY MOIST AIRMASS SHOULD FUEL INTENSE THUNDERSTORM UPDRAFTS
ACROSS THESE AREAS WHERE MID LEVEL FLOW IN EXCESS AROUND 50KT
SUPPORTS UPDRAFT PERSISTENCE AND ORGANIZATION. A NUMBER OF
SUPERCELLS ARE EXPECTED PRIOR TO A CONSOLIDATION OF STORMS INTO A
LARGE MCS TOWARD EVENING. LOW LEVEL SHEAR/HELICITY NEAR THE SURFACE
LOW AND ALONG THE FRONT WILL SUPPORT SOME TORNADOES WITH ANY
DISCRETE CELLS. A COUPLE STRONG TORNADOES SEEM POSSIBLE WITHIN THIS
ENVIRONMENT OVER THE NEXT SEVERAL HOURS IN ADDITION TO VERY LARGE
HAIL AND LOCALIZED DOWNDRAFT/DAMAGING WIND THREATS.

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
550. MEAN STORM MOTION VECTOR 28030.


...CARBIN

Updated SPC forecast for day 1.

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0300 PM CDT WED JUN 12 2013

VALID 122000Z - 131200Z

...THERE IS A HIGH RISK OF SVR TSTMS FROM EXTREME ERN IA...NRN
IL...NRN IND...EXTREME SWRN MI AND EXTREME NWRN OH...

...THERE IS A MDT RISK OF SVR TSTMS FROM ERN IA...CNTRL AND NRN
IL...SRN WI...SWRN MI...IND...AND WRN OH...

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE UPPER MS VALLEY INTO
THE OH VALLEY...SRN GREAT LAKES AND MID ATLANTIC REGION...

...THERE IS A SLGT RISK OF SVR TSTMS CNTRL AND ERN MT INTO NERN
WY...

...UPPER MS VALLEY SRN GREAT LAKES AND OH VALLEY REGION...

ONLY MINOR CHANGES HAVE BEEN MADE TO ONGOING FORECAST. THREAT FOR A
SIGNIFICANT WIDESPREAD DAMAGING WIND EVENT STILL APPEARS ON TRACK
FROM SRN PORTIONS OF THE GREAT LAKES INTO THE OH VALLEY REGION HIGH
AND MODERATE RISK AREAS.

STORMS ARE IN PROCESS OF DEVELOPING FROM NERN IA INTO SRN WI WITHIN
ZONE OF DPVA AND ASCENT ACCOMPANYING A PROGRESSIVE SHORTWAVE TROUGH
GENERALLY NE OF SFC LOW AND NORTH OF E-W QUASI-STATIONARY FRONT. THE
INITIAL SFC BASED STORMS DEVELOPING EAST OF SFC LOW MAY ORGANIZE AS
DISCRETE SUPERCELLS WITH AN INITIAL TORNADO THREAT. STORMS SHOULD
EVENTUALLY CONSOLIDATE AND TRANSITION TO A FORWARD PROPAGATING MCS
WITH AN INCREASING THREAT FOR SIGNIFICANT WIND DAMAGE AS IT MOVES
ESEWD THROUGH THE SRN GREAT LAKES AND OH VALLEY DURING THE EVENING
AND OVERNIGHT.

...MT AND NERN WY...

REF SWOMCD 1042.

..DIAL.. 06/12/2013

Currently the best environment for tornadoes extends from near DBQ to the RFD/JVL area. This is also on nose of strongest 850 mb moisture transport and just north of surface boundary in the gradient of strong instability. Mean wind is carrying storms to the northeast, but as they encounter 50 knots of 0-6km shear and beginning rotating, they should turn to the east right along the WI/IL border per Bunkers Right Moving Supercell motion vectors. So there will be large hail and then a tornado threat before the cold pool develops and a forward propagating MCS hits the Chicago area this evening.

Those developing cells to the northeast of Davenport are in their infant stages and are already exhibiting a hook characteristic.