Severe Threat June 11-13

[yoda]

Its a MOD... but they had so many regions to write about apparently

[snowlover2]

Still moderate.

[huronicane]

Moderate just posted on COD

 

10% hatched tornado across N IL. 

[yoda]

10% hatched TOR in CHI or just south

 

[huronicane]

...IA...IL AND SRN WI EARLY AFTERNOON INTO IND...OH...NRN KY AND FAR
SRN MI DURING THE EVENING...
MORNING STORMS ARE EXPECTED TO BE IN PROGRESS ACROSS SRN MN/IA AND
VICINITY...WITH SOME MARGINAL SEVERE WIND/HAIL THREAT. AS THE LOW
DEVELOPS...THESE STORMS WILL LIKELY BEGIN TO GROW UPSCALE WITH A
RAPIDLY DESTABILIZING AIR MASS TO THE E. OTHER CONVECTION MAY ALSO
FORM ALONG THE WARM FRONT E OF THE SURFACE LOW TRACK...ACROSS SRN
WI/NRN IL. INITIALLY...SOME OF THESE CELLS ARE LIKELY TO BE
SUPERCELLS...AND A STRONG TORNADO COULD OCCUR. WITH TIME...AND
PARTIALLY DUE TO WEAK UPPER LEVEL FLOW...STORMS SHOULD MERGE INTO A
LARGE CLUSTER. INCREASING WIND FIELDS WILL FAVOR A FORWARD
PROPAGATING CONVECTIVE SYSTEM...POSSIBLY A DERECHO CAPABLE OF
WIDESPREAD DAMAGING WINDS. HOWEVER...EMBEDDED AREAS OF ROTATION MAY
ALSO EXIST PERIODICALLY...INDICATING EITHER TORNADOES OR ENHANCES
SWATHS OF DAMAGING WIND POTENTIAL. LARGE HAIL IS ALSO
LIKELY...POSSIBLY WIND DRIVEN.

MODELS INDICATE THE MAIN CORRIDOR FOR WIDESPREAD DAMAGE WILL BE FROM
NRN IL INTO NRN AND CNTRL IND AND INTO OH. HOWEVER...IF THE SYSTEM
GROWS LARGER THAN EXPECTED...OTHER AREAS COULD BE UNDER A GREATER
THREAT SUCH AS NRN KY...WV...AND WRN PA. 

[Hoosier]

Beefy wording

..IA...IL AND SRN WI EARLY AFTERNOON INTO IND...OH NRN KY AND FAR SRN MI DURING THE EVENING...

MORNING STORMS ARE EXPECTED TO BE IN PROGRESS ACROSS SRN MN/IA AND VICINITY...WITH SOME MARGINAL SEVERE WIND/HAIL THREAT. AS THE LOW DEVELOPS...THESE STORMS WILL LIKELY BEGIN TO GROW UPSCALE WITH A RAPIDLY DESTABILIZING AIR MASS TO THE E. OTHER CONVECTION MAY ALSO FORM ALONG THE WARM FRONT E OF THE SURFACE LOW TRACK...ACROSS SRN WI/NRN IL. INITIALLY...SOME OF THESE CELLS ARE LIKELY TO BE SUPERCELLS...AND A STRONG TORNADO COULD OCCUR. WITH TIME...AND PARTIALLY DUE TO WEAK UPPER LEVEL FLOW...STORMS SHOULD MERGE INTO A LARGE CLUSTER. INCREASING WIND FIELDS WILL FAVOR A FORWARD PROPAGATING CONVECTIVE SYSTEM...POSSIBLY A DERECHO CAPABLE OF WIDESPREAD DAMAGING WINDS. HOWEVER...EMBEDDED AREAS OF ROTATION MAY ALSO EXIST PERIODICALLY...INDICATING EITHER TORNADOES OR ENHANCES SWATHS OF DAMAGING WIND POTENTIAL. LARGE HAIL IS ALSO LIKELY...POSSIBLY WIND DRIVEN.

MODELS INDICATE THE MAIN CORRIDOR FOR WIDESPREAD DAMAGE WILL BE FROM NRN IL INTO NRN AND CNTRL IND AND INTO OH. HOWEVER...IF THE SYSTEM GROWS LARGER THAN EXPECTED...OTHER AREAS COULD BE UNDER A GREATER THREAT SUCH AS NRN KY...WV...AND WRN PA.

[Chargers09]

Wow, was not expecting a 10% tornado risk here. Nor a 30% hatched hail risk. I think the SPC might wait on trends to see if they want to extend the mod risk north or not. Still very impressive. 

[nwburbschaser]

Been a while since there was a 10% hatched in this area that I can remember.

[Stebo]

I am still not writing off a high risk potential for wind tomorrow, their wording is very strong.

[RCNYILWX]

Beefy wording

 

Beefiest for here since 4/10/11. 

[Chargers09]

I am still not writing off a high risk potential for wind tomorrow, their wording is very strong.

This. 

[nwohweather]

Wow insane wording by the SPC. Extreme instability, steep lapse rates and veering winds aloft make NW ohio and southern Michigan very tornado prone

[nwburbschaser]

Beefiest for here since 4/10/11.

That set up changed very quickly overnight, but was probably a good thing for the Chi metro because there was some serious potential. I don't see that sort of high end potential with this system tornado wise, but then again the trend is going upwards.

[nwohweather]

Also wanna say that this hail tomorrow will be very destructive. With the kind of shear aloft we will see, I expect some very large stuff for our neck of the woods

[Thundersnow12]

Beefiest for here since 4/10/11. 

 

All I got that day was a nice Culver's lunch in IA, what a bust that was.

 

6/5/10 or 8/4/08

[Stebo]

Well tentative plan as it stands right now is end up around Niles, MI by mid afternoon, unless something dramatically changes while I sleep. Niles gives me a good flex point to deviate if need be. Good luck to anyone who goes out tomorrow, and be safe.

[snowlover2]

10% Tor/30% hatched hail/ 45% hatched wind for me. Don't think I've seen that high probs here since the high risk early last year from the storm that produced tornadoes along the OH River.

[RCNYILWX]

That set up changed very quickly overnight, but was probably a good thing for the Chi metro because there was some serious potential. I don't see that sort of high end potential with this system tornado wise, but then again the trend is going upwards.

Agreed, glad that set-up changed. IIRC, the 12z SPC WRF had a string of pearls on the max UH product over the Chicago area the next day but then the 00z run shifted to more what occurred with the discrete development way north. What's concerning now is that model, which usually does pretty well, shifted from mainly south of the metro with the potential for discrete development on the 12z to right over the metro on the 00z. The wind fields tomorrow are not quite as strong, but more than enough given the instability progged and the likely proximity to the warm frontal boundary. 

 

FWIW, last 10% hatched tor for northern IL on the 06z Day 1 (later was upgraded to 15% hatched tor and MDT): 

 

[nwburbschaser]

Was that the Joplin day? I was out of town, but I remember that the tornado threat for Northern Illinois was very real.

[hm8]

If we eventually see a high risk it'll likely be after a squall line has already formed and they can stick a 60% zone right in front of it... If memory serves that's where I've seen most high risk wind events pulled out.

Sent from my HTCONE using Tapatalk 2

[RCNYILWX]

Was that the Joplin day? I was out of town, but I remember that the tornado threat for Northern Illinois was very real.

Yup, the Joplin day indeed. Did end up with a long tracked EF1 in NW IL.

[tornadotony]

Quick look at the radars for NE/IA/IL shows absolutely nothing yet holding back the Chicagoland potential. I've got a really bad feeling about this one.

[Gilbertfly]

Yup, the Joplin day indeed. Did end up with a long tracked EF1 in NW IL.

 

they call you in at the office for today?  Busy busy day in line at LOT...I see they just hoisted flash flood watches

[Gilbertfly]

sheesh...

 

[andyhb]

sheesh...

 

SREF_prob_combined_sigtor__f021.gif

 

That looks like an awful lot like the area in IL that got hit the hardest on 6/5/10.

[SpartyOn]

DTX giving some decent wording on the potential tornado threat.

[andyhb]

LOT going all in, aside from Alek-land and the main Chicago area where good ole' Lake Michigan looks to be their hindering factor.

 

 

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
317 AM CDT WED JUN 12 2013

.DISCUSSION...
304 AM CDT

...MAJOR SEVERE WEATHER OUTBREAK LIKELY THIS AFTERNOON AND
EVENING...WITH HEAVY RAINFALL ALSO LIKELY...

EVERYTHING LINING UP FOR A SIGNIFICANT SEVERE WEATHER OUTBREAK
TODAY. SPC DAY 1 OUTLOOK HAS ENTIRE FORECAST AREA IN MODERATE RISK
OF SEVERE WITH SIGNIFICANT WIND...HAIL...AND TORNADO THREAT. AT THE
SURFACE...LOW PRESSURE OVER THE PLAINS WITH A WEAK WARM FRONT
EXTENDING EAST INTO NORTHERN IL EARLY THIS MORNING. THE LOW WILL
MOVE EAST ALONG THE IA/MO BOARDER TODAY...AND ACROSS NORTHERN IL
THIS EVENING. VERY MOIST LOW LEVEL AIR WITH SURFACE DEW POINTS IN
THE MID AND UPPER 60S IN PLACE. MAY SEE DEWPOINTS POOL IN THE LOWER
70S SOUTH OF WARM FRONT THIS AFTERNOON. THE BOUNDARY WILL INTENSIFY
AS SOUTHWEST LOW LEVEL FLOW INCREASES SOUTH OF THE FRONT AND SURFACE
WINDS BACK TO SE OR E NORTH OF THE BOUNDARY. THIS WILL PULL MODIFIED
MARINE AIR BACK ACROSS FAR NORTHERN IL. HAVE SOME CONCERNS ABOUT HOW
FAR NORTH THE WARM FRONT WILL TRAVEL. SPC DISCUSSION SUGGESTING THE
BOUNDARY WILL MOVE INTO SOUTHERN WI BUT WITH MODELS TAKING LOW
ACROSS I-80 CORRIDOR AND COOLING INFLUENCE OF LAKE
MICHIGAN...THINKING FRONT WONT GET MUCH FARTHER NORTH THAN A
DIXON-GARY LINE. THIS MAY LIMIT NORTHERN EXTEND OF SIGNIFICANT
SEVERE THREAT. THE BOUNDARY WILL ALSO RESULT IN A CHALLENGING
TEMPERATURE FORECAST...WITH TEMPS REACHING LOWER 90S FAR SOUTHERN
PART OF FORECAST AREA...WHILE AREAS ALONG THE NORTH SHORE WILL
LIKELY BE 20 DEGREES COOLER. IT APPEARS THAT MOST OF THE OVERNIGHT
EARLY MORNING CONVECTION WILL AFFECT WI...BUT KEEPING AN EYE ON
MCS OVER WESTERN IA WHICH COULD MOVE INTO NORTHERN IL THIS
MORNING. EARLIER CONVECTION OVER EASTERN IA WEAKENED AS IT MOVED
EAST AND THINK THIS MCS MAY DO THE SAME. CLOUD DEBRIS SHOULD
REMAIN NORTH ALLOWING AREAS SOUTH OF THE WARM FRONT TO HEAT UP
SIGNIFICANTLY...INTO THE UPPER 80S TO LOWER 90S. THIS COULD RESULT
IN SURFACE BASED CAPE OF 3000+ THIS AFTERNOON. FAIRLY VIGOROUS
SHORT WAVE MOVING INTO WESTERN SD/NE EARLY THIS MORNING WILL BE
MOVING ACROSS NORTHERN IL THIS EVENING. MODEL SOUNDINGS SHOW
FAIRLY STOUT CAP EARLY IN THE DAY ERODES THIS AFTERNOON WITH
APPROACHING SHORT WAVE. LOOKING AT 0-6KM BULK SHEAR 50-60 KTS BY
THIS EVENING. WITH INCREASING LOW LEVEL FLOW THIS AFTERNOON AND
BACKING SURFACE WINDS ALONG THE BOUNDARY...SHOULD PRODUCE AN
ENVIRONMENT FAVORABLE FOR DAMAGING WINDS...LARGE HAIL...AND
TORNADOES. SOME OF THE SHORT RANGE HI RES GUIDANCE IS SUGGESTING
DISCRETE STORMS INITIALLY THIS AFTERNOON. EXPECT THE TORNADO
THREAT TO BE MAINLY DURING THE AFTERNOON. STORMS WILL LIKELY
CONGEAL INTO AN MCS AND BECOME MORE OF A HIGH WIND WITH EMBEDDED
QLCS TORNADO THREAT IN THE EVENING. THE OTHER CONCERN IS WITH
PWATS AROUND 2 INCHES...AND SURFACE DEW POINTS NEAR
70...THUNDERSTORMS WILL BE CAPABLE OF VERY HEAVY RAINFALL AND AS
MCS DEVELOPS...FLOODING WILL ALSO BE A CONCERN. MODEL CONSENSUS IS
TO PLACE HEAVIEST QPF NORTH OF THE BOUNDARY OVER THE RFD AND
CHICAGO AREAS. SEE HYDRO SECTION OF THE AFD BELOW.

[Gilbertfly]

That looks like an awful lot like the area in IL that got hit the hardest on 6/5/10.

 

and this may help feed right into the same areas....

 

via LOT...

THE BOUNDARY WILL INTENSIFY

AS SOUTHWEST LOW LEVEL FLOW INCREASES SOUTH OF THE FRONT AND SURFACE

WINDS BACK TO SE OR E NORTH OF THE BOUNDARY. THIS WILL PULL MODIFIED

MARINE AIR BACK ACROSS FAR NORTHERN IL. HAVE SOME CONCERNS ABOUT HOW

FAR NORTH THE WARM FRONT WILL TRAVEL. SPC DISCUSSION SUGGESTING THE

BOUNDARY WILL MOVE INTO SOUTHERN WI BUT WITH MODELS TAKING LOW

ACROSS I-80 CORRIDOR AND COOLING INFLUENCE OF LAKE

MICHIGAN...THINKING FRONT WONT GET MUCH FARTHER NORTH THAN A

DIXON-GARY LINE. THIS MAY LIMIT NORTHERN EXTEND OF SIGNIFICANT

SEVERE THREAT.

 

 

just a snippet from LOT above ^^^

[andyhb]

DVN is not pulling any punches either.

 

 

A VERY SOBERING SITUATION IS DEVELOPING EARLY THIS MORNING. A
CAPPED HIGH CAPE AIRMASS IS FOUND FROM IOWA SOUTHWARD...A STRONG
SHORT WAVE IS DROPPING INTO THE DAKOTAS...LOW PRESSURE IN SOUTH
CENTRAL NEBRASKA IS MOVING EAST ALONG A STALLED FRONTAL BOUNDARY.
THIS FRONT IS FOUND FROM OMAHA EASTWARD OVER IOWA TO THE QUAD
CITIES...TO NORTHERN INDIANA. MCS ACTIVITY IS OCCURRING JUST NORTH OF
THIS STALLED BOUNDARY...ENHANCING THE CONVERGENCE BY BACKING THE
WINDS ALONG IT.

SPC HAS ALREADY OUTLINED THE THREATS TODAY VERY WELL IN THEIR DAY 1
GRAPHICS...AS I STRONGLY BELIEVE THERE WILL BE SEVERAL HOURS OF
SUPERCELL THUNDERSTORMS THIS AFTERNOON OVER THE NORTHERN 1/2 OF THE
CWA...ALONG THE STALLED BOUNDARY. THIS PLACES A TORNADO RISK INTO THE
CEDAR RAPIDS...DUBUQUE...CLINTON...QUAD CITIES...FREEPORT...STERLING
...GENESEO...AND PRINCETON METRO AREAS. AS NOTED BY SPC...THERE IS A
RISK FOR A FEW STRONG TORNADOES...ESPECIALLY RIGHT NEAR THE BOUNDARY
WHERE THE STRONGEST LOW LEVEL INSTABILITY SHOULD BE FOUND...ALONG
WITH BACKED WINDS...CREATING A MORE STRONGLY CURVED HODOGRAPH. AT
THIS TIME...THIS APPEARS TO BE LOCATIONS ROUGHLY ALONG INTERSTATE
80...EAST OF IOWA CITY.

THE CAP WHICH PREVENTED CONVECTION YESTERDAY IS NOW WORKING AGAINST
US. THUS FAR THROUGH 2 AM...IT HAS PREVENTED STORMS FROM FORMING IN
THE SOUTH HALF IOWA. OUR SAVIOR OUT OF THIS EVENT IS MOST CERTAINLY
GETTING STORMS TO PUSH THE BOUNDARY SOUTH...BUT EVEN WITH A LARGE
FLARE UP IN STORMS IN NORTHWEST IOWA...THE CAP IS SO STRONG THAT
STORMS MAY ONLY SWIPE THE NORTHERN 2 ROWS OF COUNTIES. AT THIS
POINT...SINCE MODELS ARE CORRECTLY SHOWING THE STORMS TO THE
NORTHWEST REMAINING ON AN EAST TO NORTHEAST PROGRESS...I HAVE TO
BELIEVE THE BOUNDARY WILL NOT DROP FARTHER SOUTH...AND STRONG
HEATING/HIGH CAPE WILL OCCUR IN THE SOUTHERN 1/2 OF THE CWA SETTING
THE STAGE FOR OUR POTENTIAL SEVERE EVENT. THIS SAID...I WILL
CONTINUE TO MONITOR CONVECTIVE TRENDS...AND HOPE OUR CAPPING
WEAKENS...BUT THAT SEEMS UNLIKELY AHEAD OF THE COMING STRONG SHORT
WAVE IN THE DAKOTA. AFTER HIGHS REACH THE UPPER 80S TODAY...THE
LOW SHOULD BE POISED NEAR DES MOINES...AND WILL SWEEP EAST TO THE
MISSISSIPPI RIVER BY 7 PM THIS EVENING. THUS...SUPERCELLS SHOULD
BREAK OUT BY EARLY TO MID AFTERNOON...WITH A TORNADO RISK IN THE
AFOREMENTIONED AREAS...THIS SHOULD THEN CONGEAL WITH STORMS NEAR THE
LOW AND ALONG THE COLD FRONT IN CENTRAL IOWA THIS LATE AFTERNOON.
FROM THIS POINT ON A INTENSE DERECHO SHOULD FORM...AND SWEEP
EASTWARD. WIDESPREAD WIND THREAT IS EXPECTED...WITH WINDS THAT
SHOULD EASILY REACH 80 MPH IN BOWING SEGMENTS. THIS IS POSSIBLE IN
ALL AREAS EAST OF I-280...BUT ESPECIALLY IN THE ILLINOIS COUNTIES.
IN SOUTHEAST IOWA...NORTHERN MISSOURI...AND WEST CENTRAL
ILLINOIS...IT IS THE DAMAGING WINDS WITH THE MAIN LOW PASSAGE THAT
WILL BE THE PRIMARY THREAT...UNLESS THE BOUNDARY DROPS WELL SOUTH AS
MENTIONED AS A LOWER POSSIBILITY.

STAY INFORMED. TAKE WARNINGS VERY SERIOUSLY TODAY. KNOW WHERE YOU
WILL TAKE SHELTER THIS AFTERNOON IF IT IS REQUIRED. SHUT YOUR GARAGE
DOOR.

[Gilbertfly]

rare wording via LOT's HWO...

.

 

Hazardous Weather Outlook

HAZARDOUS WEATHER OUTLOOKNATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL408 AM CDT WED JUN 12 2013ILZ003>006-008-010>014-019>023-032-033-039-INZ001-002-010-011-019-130915-WINNEBAGO-BOONE-MCHENRY-LAKE ILLINOIS-OGLE-LEE-DE KALB-KANE-DUPAGE-COOK-LA SALLE-KENDALL-GRUNDY-WILL-KANKAKEE-LIVINGSTON-IROQUOIS-FORD-LAKE INDIANA-PORTER-NEWTON-JASPER-BENTON-408 AM CDT WED JUN 12 2013 /508 AM EDT WED JUN 12 2013/THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTH CENTRAL ILLINOIS...NORTHEAST ILLINOIS AND NORTHWEST INDIANA..DAY ONE...TODAY AND TONIGHT.  WEATHER HAZARDS EXPECTED:  NUMEROUS THUNDERSTORMS...SOME COULD PRODUCE:   STRONG TORNADOES   DAMAGING WINDS IN EXCESS OF 75 MPH   HAIL TO THE SIZE OF BASEBALLS   VERY HEAVY RAINFALL WHICH COULD CAUSE FLASH FLOODING  AREAS AFFECTED AND TIMING:   A CLUSTER OF THUNDERSTORMS OVER IOWA WILL LIKELY BE WEAKENING   AS IT MOVES ACROSS FAR NORTHERN ILLINOIS THIS MORNING.   SCATTERED THUNDERSTORMS ARE EXPECTED TO REDEVELOP EARLY THIS   AFTERNOON OVER NORTHWEST AND NORTH CENTRAL ILLINOIS. THE STORMS   ARE EXPECTED TO BECOME MORE WIDESPREAD LATE THIS AFTERNOON AND   EVENING AS THEY SPREAD ACROSS NORTHEAST ILLINOIS AND NORTHWEST   INDIANA.  DISCUSSION:   A STRONG UPPER LEVEL DISTURBANCE WILL MOVE ACROSS THE REGION   THIS EVENING. LOW PRESSURE AT THE SURFACE WILL MOVE ALONG A   NEARLY STATIONARY WARM FRONT ACROSS NORTHERN ILLINOIS AND   INDIANA THIS EVENING. A VERY WARM...HUMID AND UNSTABLE AIR MASS   WILL BE IN PLACE ALONG AND SOUTH OF THE WARM FRONT. THE   COMBINATION OF STRONG INSTABILITY AND STRENGTHENING WIND SHEAR   WILL BE FAVORABLE FOR A SIGNIFICANT SEVERE WEATHER OUTBREAK   FROM MID AFTERNOON THROUGH THIS EVENING. IN ADDITION... HEAVY   RAINFALL...MAINLY ALONG AND NORTH OF THE I-80 CORRIDOR WILL LEAD   TO THE POTENTIAL FOR FLASH FLOODING LATE THIS AFTERNOON AND   TONIGHT..DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY.THERE IS AN INCREASED RISK FOR RIP CURRENTS THURSDAY.THERE IS A CHANCE OF THUNDERSTORMS SATURDAY THROUGH MONDAY..SPOTTER INFORMATION STATEMENT...SPOTTERS WILL LIKELY BE NEEDED THIS AFTERNOON AND EVENING.