Tornado Warning 9, NWS Chicago, IL

973 
WWUS53 KLOT 100015
SVSLOT

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
715 PM CDT THU APR 9 2015

ILC007-141-201-100045-
/O.CON.KLOT.TO.W.0009.000000T0000Z-150410T0045Z/
BOONE IL-OGLE IL-WINNEBAGO IL-
715 PM CDT THU APR 9 2015

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 745 PM CDT FOR
SOUTHWESTERN BOONE...NORTHEASTERN OGLE AND SOUTHEASTERN WINNEBAGO
COUNTIES...
    
AT 715 PM CDT...A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO 
WAS LOCATED JUST EAST OF STILLMAN VALLEY...MOVING EAST AT 40 MPH.

HAZARD...TORNADO. 

SOURCE...RADAR INDICATED ROTATION. 

IMPACT...FLYING DEBRIS WILL BE DANGEROUS TO THOSE CAUGHT WITHOUT 
         SHELTER. MOBILE HOMES WILL BE DAMAGED OR DESTROYED. DAMAGE 
         TO ROOFS...WINDOWS AND VEHICLES WILL OCCUR.  TREE DAMAGE IS 
         LIKELY. 

OTHER LOCATIONS IMPACTED BY THIS TORNADIC THUNDERSTORM INCLUDE NEW 
MILLFORD AND DAVIS JUNCTION.

INCLUDING THE FOLLOWING INTERSTATES...
 I-39 BETWEEN MILE MARKERS 110 AND 123.
 I-90 BETWEEN MILE MARKERS 61 AND 62.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! MOVE TO A BASEMENT OR AN INTERIOR ROOM ON THE LOWEST
FLOOR OF A STURDY BUILDING. AVOID WINDOWS. IF YOU ARE OUTDOORS...IN A
MOBILE HOME...OR IN A VEHICLE...MOVE TO THE CLOSEST SUBSTANTIAL
SHELTER AND PROTECT YOURSELF FROM FLYING DEBRIS.

&&

LAT...LON 4217 8884 4215 8888 4215 8894 4212 8894
      4204 8910 4214 8923 4233 8906
TIME...MOT...LOC 0015Z 251DEG 35KT 4212 8910 

TORNADO...RADAR INDICATED
HAIL...<.75IN

$$

BMD

133 
WWUS53 KLOT 100025
SVSLOT

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
725 PM CDT THU APR 9 2015

ILC007-141-201-100045-
/O.CON.KLOT.TO.W.0009.000000T0000Z-150410T0045Z/
BOONE IL-OGLE IL-WINNEBAGO IL-
725 PM CDT THU APR 9 2015

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 745 PM CDT FOR
SOUTHWESTERN BOONE...EAST CENTRAL OGLE AND SOUTHEASTERN WINNEBAGO
COUNTIES...
    
AT 725 PM CDT...A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO
WAS LOCATED NEAR CHERRY VALLEY...OR 7 MILES SOUTHEAST OF ROCKFORD
AIRPORT...MOVING EAST AT 40 MPH.

HAZARD...TORNADO. 

SOURCE...RADAR INDICATED ROTATION. 

IMPACT...FLYING DEBRIS WILL BE DANGEROUS TO THOSE CAUGHT WITHOUT 
         SHELTER. MOBILE HOMES WILL BE DAMAGED OR DESTROYED. DAMAGE 
         TO ROOFS...WINDOWS AND VEHICLES WILL OCCUR.  TREE DAMAGE IS 
         LIKELY. 

INCLUDING THE FOLLOWING INTERSTATE... I-39 BETWEEN MILE MARKERS 110 
AND 116...AND BETWEEN MILE MARKERS 121 AND 122.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! MOVE TO A BASEMENT OR AN INTERIOR ROOM ON THE LOWEST
FLOOR OF A STURDY BUILDING. AVOID WINDOWS. IF YOU ARE OUTDOORS...IN A
MOBILE HOME...OR IN A VEHICLE...MOVE TO THE CLOSEST SUBSTANTIAL
SHELTER AND PROTECT YOURSELF FROM FLYING DEBRIS.

&&

LAT...LON 4217 8884 4215 8888 4215 8894 4212 8894
      4206 8906 4212 8909 4225 8896
TIME...MOT...LOC 0025Z 251DEG 35KT 4215 8897 

TORNADO...RADAR INDICATED
HAIL...<.75IN

$$

BMD

097 
WWUS53 KLOT 100044
SVSLOT

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
744 PM CDT THU APR 9 2015

ILC007-141-201-100053-
/O.EXP.KLOT.TO.W.0009.000000T0000Z-150410T0045Z/
BOONE IL-OGLE IL-WINNEBAGO IL-
744 PM CDT THU APR 9 2015

...THE TORNADO WARNING FOR SOUTHWESTERN BOONE...EAST CENTRAL OGLE AND
SOUTHEASTERN WINNEBAGO COUNTIES WILL EXPIRE AT 745 PM CDT...
        
THE STORM WHICH PROMPTED THE WARNING HAS MOVED OUT OF THE AREA.
THEREFORE THE WARNING WILL BE ALLOWED TO EXPIRE.  HOWEVER GUSTY WINDS
AND HEAVY RAIN ARE LIKELY WITH THIS THUNDERSTORM.

A TORNADO WATCH REMAINS IN EFFECT UNTIL 1100 PM CDT FOR NORTH CENTRAL
ILLINOIS.

REMEMBER...A TORNADO WARNING STILL REMAINS IN EFFECT FOR 
SOUTHEASTERN BOONE COUNTY.

LAT...LON 4217 8884 4215 8888 4215 8894 4212 8894
      4206 8906 4212 8909 4225 8896
TIME...MOT...LOC 0041Z 251DEG 35KT 4215 8897 

$$

BMD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
536 PM CDT THU APR 9 2015

.MESOSCALE DISCUSSION...
536 PM CDT

CONTINUE TO MONITOR COLD FRONT WITH STRONG CONVECTION OCCURRING
NEAR THE MISSISSIPPI RIVER THIS HOUR. AHEAD OF THE FRONT WITHIN
THE WARM SECTOR THUNDERSTORMS HAVE STRUGGLED TO REACH THEIR FULL
POTENTIAL WITH MODEST MID LEVEL LAPSE RATES BEING ONE OF THE
PRIMARY LIMITING FACTORS. WIDELY SCATTERED ACTIVITY WILL CONTINUE
AHEAD OF THE FRONT THROUGH MID EVENING...THOUGH GIVEN TRENDS SO
FAR THE THREAT FOR SEVERE WEATHER APPEARS LOW AHEAD OF THE FRONT.
WITH CIRRUS SHIELD OVERSPREADING THE REGION AND LOWERING SUN
ANGLE...THERE ARE RENEWED CONCERNS REGARDING
INSTABILITY...ESPECIALLY AS WE GET CLOSER TO SUNSET THIS EVENING.
EXPECT MODERATE INSTABILITY TO PERSIST THROUGH 00Z THEN FOR A
DIMINISHING TREND OF MLCAPE THEREAFTER.

BY 00Z/7PM CDT...EXPECT THE LINE OF THUNDERSTORMS ASSOCIATED WITH
THE COLD FRONT WHICH WILL MAINTAIN A HIGHER SEVERE THREAT TO BE
NEAR THE I-39 CORRIDOR...AND ENTERING THE WESTERN SUBURBS OF
CHICAGO CLOSER TO 01Z/8PM CDT. LOW LEVEL CONVERGENCE ALONG THE
FRONT REMAINS STRONG AND DEEP LAYER SHEAR REMAINS SUFFICIENT TO
SUSTAIN AT LEAST SOME ORGANIZED/SEVERE THREAT THROUGH THE HEART OF
THE FORECAST AREA...THOUGH DIMINISHING MLCAPE MAY EVENTUALLY LOWER
THAT THREAT.

DEUBELBEISS

&&

.SHORT TERM...
400 AM CDT

TODAY AND TONIGHT...

DENSE FOG CONTINUES IN COOL/SATURATED AIR MASS WITH NORTHEAST
WINDS OFF THE LAKE THIS MORNING...WILL MAINTAIN DENSE FOG ADVISORY
ALONG THE LAKE AS ISSUED.

CLUSTERS OF THUNDERSTORMS WERE OCCURRING EARLY THIS MORNING
ACROSS THE MIDWEST...IN A REGION OF BROAD SOUTHWESTERLY WARM/MOIST
ADVECTION ATOP NEARLY STATIONARY FRONTAL BOUNDARY WHICH STRETCHES
FROM THE CENTRAL PLAINS INTO SOUTHERN IOWA...THEN EAST ACROSS
CENTRAL ILLINOIS AND INDIANA. THESE CLUSTERS OF STORMS WERE
GENERALLY TIED TO INDIVIDUAL MINOR-AMPLITUDE MID-LEVEL SHORT WAVE
FEATURES...AND ASSOCIATED LOCALIZED ENHANCED MOISTURE TRANSPORT
AND ASCENT. TO THE WEST...STRONG UPPER TROUGH WAS MOVING ONTO THE
PLAINS EAST OF THE ROCKIES...AND IS PROGGED TO APPROACH THE MID-
UPPER MISSISSIPPI VALLEY LATE THIS AFTERNOON AS A COMPACT AND
SOMEWHAT NEGATIVELY-TILTED ENERGETIC DISTURBANCE. SURFACE LOW
PRESSURE IN THE VICINITY OF SOUTHWEST KANSAS AT THIS HOUR WILL
DEEPEN AND LIFT TO SOUTHWESTERN WISCONSIN/FAR NORTHWEST IL PER
COMPLIMENTING GUIDANCE SOLUTIONS...WITH THE FRONT LIFTING NORTH AS
A WARM FRONT ACROSS THE FORECAST AREA. THIS PATTERN HAS ALL THE
EARMARKS OF BEING A WIDESPREAD SEVERE WEATHER PRODUCER ACROSS THE
AREA THIS AFTERNOON AND EVENING.

WITH THAT SAID...QUESTIONS REMAIN WITH RESPECT TO EVOLUTION OF
STORMS LATER TODAY...MAINLY DUE TO THE EXPECTATION THAT SEVERAL
CLUSTERS OF STORMS WILL CONTINUE TO DEVELOP/PROPAGATE ACROSS THE
AREA THROUGH MUCH OF THE DAY DUE TO PERSISTENT WARM/MOIST
ADVECTION AND ASCENT IN REGION OF STEEP MID-LEVEL LAPSE RATES
AHEAD OF THE DEEPENING TROUGH AND SURFACE LOW. CONVECTION ALLOWING
GUIDANCE (HRRR/NMM/ARW RUNS) DEPICT SEVERAL CLUSTERS DEVELOPING
AND LIFTING ACROSS THE AREA THROUGH THE MORNING AND MIDDAY
HOURS...AND REGIONAL RADAR MOSAIC SEEMS TO INDICATE THIS WILL BE
THE TREND AT LEAST THROUGH THIS MORNING. THUS WHILE SYNOPTIC
FEATURES WILL BE STRONG...MESOSCALE BOUNDARIES AND FORCING REMAIN
UNCLEAR AT THIS TIME. STILL...STRONG FORCING IN ADVANCE OF COLD
FRONT COUPLED WITH STRONG ASCENT ASSOCIATED WITH COMPACT WAVE
SHOULD BE CAPABLE OF GENERATING ORGANIZED SEVERE STORMS LATER THIS
AFTERNOON. 00Z NAM FORECAST SOUNDINGS INDICATE WARM SECTOR MLCAPES
AROUND 1500-2000 J/KG...WITH AMPLE DEEP AND LOW LEVEL SHEAR. SPC
NOTES SOME UNCERTAINTY WITH RESPECT TO STORM MODE...LINE SEGMENTS
AS OPPOSED TO DISCRETE CELLS...THOUGH SUPERCELLULAR
CHARACTERISTICS ARE LIKELY GIVEN THE ENVIRONMENT. DAMAGING WINDS
FROM LINES/LINE SEGMENTS LOOKS TO BE THE MOST WIDESPREAD
THREAT...THOUGH NORTHERN IL/SOUTHERN WI...WHERE WINDS WILL MOST
LIKELY BE BACKED MORE STRONGLY AHEAD OF THE LOW...WILL STILL HAVE
A REAL TORNADO POTENTIAL. STORMS WILL LIKELY EVOLVE UPSCALE INTO
SQUALL-LINE AS COLD FRONT MOVES ACROSS THE AREA EARLY THIS
EVENING...WITH THUNDERSTORM/SEVERE THREAT QUICKLY WINDING DOWN
BEFORE MIDNIGHT AFTER FROPA.

RATZER

&&

.LONG TERM...
257 PM CDT

FRIDAY THROUGH THURSDAY...

FOLLOWING A PERIOD OF VERY ACTIVE WEATHER...FOLLOWING THE PASSAGE OF
THE COLD FRONT LATE THURSDAY NIGHT...A PERIOD OF RELATIVE CALM WILL
SET UP FOR FRIDAY INTO SUNDAY AS A COOL...DRY HIGH PRESSURE AREA
BUILDS ACROSS THE AREA.  TEMPERATURES WILL DROP BACK TO CLOSER TO
SEASONAL HIGHS NORMAL LEVELS WITH HIGHS IN THE UPPER 50S TO AROUND
60F UNDER MOSTLY SUNNY SKIES.  AS THE HIGH WILL BE RIGHT OVER THE
AREA FRIDAY NIGHT INTO SATURDAY MORNING...LIGHT WINDS AND A DRY
AIRMASS WILL ALLOW FOR SOME ENHANCED RADIATIVE COOLING OVERNIGHT FOR
LOWS TO DROP BACK INTO THE MIDDLE TO UPPER 30S SATURDAY MORNING.
WITH THE HIGH BEGINNING TO BUILD OFF TO THE EAST THROUGH SATURDAY
NIGHT AND SUNDAY...A RETURN FLOW OF MOISTURE AND WARMER AIR WILL
KEEP THE COOLING TREND VERY BRIEF WITH TEMPS REBOUNDING BACK TO
AROUND 60F OVER MUCH OF THE CWA...WITH THE EXCEPTION OF THE
IMMEDIATE LAKEFRONT...WHICH SHOULD REMAIN COOLER AS A WEAK PRESSURE
GRADIENT AND DIFFERENTIAL HEATING BETWEEN THE COOL LAKE WATER AND
WARMER LAKE SHOULD ALLOW A LAKE BREEZE TO DEVELOP.  HIGHS ON
SATURDAY ALONG THE LAKE FRONT TOPPING OUT IN THE MIDDLE 50S.
INCREASING SOUTHERLY FLOW ON THE WESTERN PERIPHERY OF THE HIGH
MOVING OFF TO THE EAST WILL LIKELY PREVENT A LAKE BREEZE FROM
DEVELOPING.

FOR SUNDAY...A NORTHERN STREAM SHORT WAVE MOVING OUT OF THE NRN
ROCKIES SHOULD BEGIN TO PHASE WITH A SOUTHERN STREAM SHORTWAVE
LIFTING INTO THE MIDDLE MISSISSIPPI VALLEY.  THIS PHASING SHOULD
RESULT IN AN AMPLIFYING LONG WAVE TROUGH OVER THE MIDDLE AND UPPER
MISSISSIPPI VALLEY AND BRINGING THE NEXT CHANCE OF PCPN TO THE
REGION.  THE LONGER RANGE GUIDANCE...IN GENERAL...AGREE ON THE
SCENARIO...BUT DIFFERENCES IN THE TIMING OF THE INDIVIDUAL SHORTWAVE
AND THE DEGREE OF PHASING AND THE RESULTANT STRENGTH OF THE LONG
WAVE TROUGH LEAD TO A RELATIVELY LOW CONFIDENCE FORECAST FOR THE
LATTER PORTIONS OF THE EXTENDED FORECAST PERIOD.  CURRENTLY FEEL
THAT A COLD FRONT MOVING ACROSS THE AREA SUNDAY INTO SUNDAY NIGHT
AND THEN SHUTTING OFF BY MONDAY MORNING AS ANOTHER HIGH PRESSURE
SYSTEM MOVES ACROSS THE AREA.  WHILE THERE IS MODERATE TO HIGH
CONFIDENCE IN A PERIOD OF PCPN SUNDAY AND SUNDAY NIGHT...START AND
END TIMES REMAIN UNCERTAIN AS WELL AS THE CHANCES FOR THUNDERSTORMS
WITH THE PCPN AND WILL LIKELY BE HIGHLY DEPENDENT ON THE SPEED OF AN
ASSOCIATED COLD FRONT MOVING THROUGH THE AREA.  FOR THE LATTER
PORTIONS OF THE FORECAST PERIOD...FROM TUESDAY THROUGH
THURSDAY...THERE COULD BE ANOTHER PERIOD OF UNSETTLED WEATHER AS THE
UPPER LEVEL FLOW PATTERN MAINTAINS A HIGH AMPLITUDE...QUICKLY
PROGRESSIVE PATTERN.  THE GFS/ECMWF ARE ACTUALLY SHOWING BETTER
CONSISTENCY FOR THE END OF THE LONGER TERM FORECAST PERIOD THAN
EARLIER...WITH ANOTHER LONG WAVE TROUGH DEVELOPING OVER THE CNTRL
PLAINS.  THE ECMWF IS TRENDING A BIT STRONGER AND DEVELOPING MORE OF
A NEGATIVE TILT TO THE TROUGH AND A CLOSED UPPER LOW BY WEDNESDAY
NIGHT...THE GFS IS REMARKABLY SIMILAR...BUT ABOUT 24 HOURS SLOWER IN
DEVELOPING THE NEGATIVE TILT UPPER TROUGH AND CLOSED UPPER LOW.
SHOULD THIS SCENARIO PAN OUT...THE MIDDLE OF NEXT WEAK COULD BE RIPE
FOR ANOTHER PERIOD OF ACTIVE WEATHER.

KREIN

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 22Z...

* SCATTERED STORMS EXPECTED THIS AFTN...WITH THE FINAL ROUND OF
  STORMS MOVING THROUGH ARND 130-2Z. SOME OF THESE STORMS COULD BE
  SEVERE WITH GUSTY WINDS.

* GUSTY SSW WINDS WITH GUSTS ARND 25 KT.

* IFR VSBY EXPECTED WITH TSRA.

* IFR CIGS BEHIND THE LINE OF STORMS OVER NIGHT...BECOMING MVFR

* GUSTY WINDS BCMG SW TO W ARND MIDNIGHT WITH MAX GUSTS 30-35 KT.

JEE/KMD

//DISCUSSION...UPDATED 22Z...

STILL EXPECTING POP UP STORMS AHEAD OF THE MAIN LINE...THOUGH THE
MAIN ACTIVITY REACHES KRFD AROUND 0Z...0130Z AROUND KORD...AND
0200Z AT THE LAKEFRONT. IFR CIGS/VSBYS...GUSTY WINDS..AND HEAVY
DOWNPOURS WITH THIS LINE.

KMD

PREVIOUS DISCUSSION FROM 18Z...

STILL LOOKING AT A VERY MESSY FORECAST AS THE PIECES NECESSARY FOR
WIDESPREAD STORMS ARE NOT COMPLETELY LINING UP. THE SFC LOW IS
OVER IOWA WHILE ITS WARM FRONT STRETCHES FROM IOWA CITY IOWA
THROUGH ORD AND ITS COLD FRONT IS OVER WESTERN MO. THE LINGERING
CLOUD COVER IS INHIBITING DEVELOPMENT EARLY THIS AFTERNOON BUT
THINKING STRONG LIFT FROM THE LOW PRESSURE SYSTEM WILL ALLOW
STORMS TO DEVELOP. THINKING STORMS WILL GET STARTED OVER IOWA AND
CENTRAL IL AND REACH THE EASTERN TERMINALS LATE THIS AFTERNOON
INTO THE EARLY EVENING. FOR RFD...WILL LIKELY SEE STORMS A BIT
EARLIER IN THE MID TO LATE AFTN. ONCE AGAIN SOME OF THESE STORMS
MAY BE SVR WITH LARGE HAIL...DAMAGING WINDS...AND MAYBE AN
ISOLATED TORNADO.

THE COLD FRONT SWINGS THROUGH THIS EVENING WITH ANOTHER ROUND OF
ORGANIZED STORMS EXPECTED ALONG IT. IFR VSBY AND MVFR CIGS ARE
PSBL ONCE AGAIN. WINDS SHIFT TO THE SW AND W BEHIND THE FRONT WITH
GUSTS UP TO 30 KT. GUSTY WEST WINDS WITH VFR CIGS AND VSBY ARE
EXPECTED TOMORROW.

JEE

//ORD AND MDW CONFIDENCE...UPDATED 22Z...

* HIGH CONFIDENCE IN SCATTERED STORMS THIS AFTN FOLLOWED BY A
  SEGMENT OR LINE OF STORMS THIS EVENING. MEDIUM CONFIDENCE IN
  COVERAGE THIS AFTERNOON AND TIMING.

* MEDIUM CONFIDENCE IN WIND DIRECTION BEHIND THE SCATTERED STORMS.
  WINDS COULD BE CHAOTIC FOR A BRIEF PERIOD OF TIME.

* HIGH CONFIDENCE IN REDUCED VSBY UNDER STORMS...MEDIUM-LOW
  CONFIDENCE IN CIG HEIGHTS.

* HIGH CONFIDENCE IN LOWER CIGS TONIGHT...LOW ON SPECIFIC HEIGHTS
  AND HOW LONG IFR WILL LAST.

* MEDIUM CONFIDENCE IN WIND GUSTS OVERNIGHT AND TOMORROW...GUSTS
  COULD BE HIGHER.

JEE/KMD

//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...

* FRIDAY NIGHT...SLIGHT CHANCE OF SHRA. MVFR POSSIBLE. NORTHWEST
  WINDS.
* SATURDAY...DRY/VFR. SOUTHWEST WINDS. LAKE BREEZE POSSIBLE.
* SUNDAY...DRY/VFR. GUSTY SOUTH WINDS.
* MONDAY...DRY/VFR. EAST WINDS.
* TUESDAY...CHANCE OF SHRA/TSRA. MVFR POSSIBLE. SOUTH WINDS.
* WEDNESDAY...CHANCE OF SHRA. SOUTH WINDS.

&&

.MARINE...
315 PM CDT

CONDITIONS OVER LAKE MICHIGAN ARE DETERIORATING RAPIDLY
TODAY...FIRST WITH WAVES OF THUNDERSTORMS CROSSING THE SOUTHERN
PORTIONS OF THE LAKE AS A WARM FRONT LIFTS NORTHWARD.  AS OF 3PM
CDT...THE FRONT HAD MOVED UP TO THE CENTER OF THE LAKE AND SHOULD
CONTINUE TO LIFT NORTHWARD AS DEEPENING LOW PRESSURE OVER EASTERN
IOWA CONTINUES TO DEEPEN AND TRACKS INTO SOUTHERN WISCONSIN BY EARLY
THIS EVENING.  BY THIS POINT...THE SOUTHERLY FLOW WILL REACH ALMOST
TO THE NORTH END OF THE LAKE...BUT WITH STRONG PRESSURE FALLS AND A
STRENGTHENING PRESSURE GRADIENT OVER THE LAKE AS THE SFC LOW
APPROACHES...WINDS OVER THE SRN PORTIONS OF THE LAKE SHOULD INCREASE
TO GALE FORCE FOR THE NEARSHORE WATERS AND THE SOUTH HALF OF THE
LAKE.  THUNDERSTORMS WILL ALSO CONTINUE TO BE A CONCERN INTO THE
EVENING AS WELL.  THE SFC LOW IS EXPECTED TO TRACK ACROSS THE CNTRL
PORTIONS OF THE LAKE LATE THIS EVENING...WITH WINDS QUICKLY SHIFTING
TO WLY-NWLY.  A STRONG NORTHERLY GRADIENT BEHIND THE EXITING
LOW...INCREASING COLD ADVECTION ASSOCIATED WITH A COOL HIGH PRESSURE
SYSTEM DROPPING INTO THE NRN PLAINS AND STRONG PRESSURE RISES AS A
RESULT OF THE COMBINATION OF THE EXITING LOW AND APPROACHING
HIGH...SHOULD ALL COMBINE TO BRING SHORT PERIOD OF WEST TO NWLY
GALES TO THE LAKE INTO FRIDAY AFTERNOON.  THE APPROACHING HIGH
SHOULD BEGIN TO OVERSPREAD THE WESTERN GREAT LAKES BY FRIDAY
AFTERNOON...ALLOWING WINDS OVER THE LAKE TO DROP OFF RELATIVELY
QUICKLY.  FOR THE WEEKEND AND INTO EARLY NEXT WEEK...CONDITIONS OVER
THE LAKE SHOULD BE RELATIVELY QUIET.  ANOTHER COLD FRONT IS EXPECTED
TO SWEEP ACROSS THE LAKE SUNDAY NIGHT OR MONDAY...BUT THIS SHOULD BE
A LESS DYNAMIC SYSTEM...AND WINDS SHOULD NOT GET AS STRONG AS WITH
THE SYSTEM APPROACHING THE LAKE AT THE CURRENT TIME.

KREIN

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...GALE WARNING...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-
     LMZ779...10 PM THURSDAY TO 1 PM FRIDAY.

&&

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
328 PM CDT THU APR 9 2015

ILZ003>006-008-010>014-019>023-032-033-039-INZ001-002-010-011-019-
102030-
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-
328 PM CDT THU APR 9 2015

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTH CENTRAL ILLINOIS...
NORTHEAST ILLINOIS AND NORTHWEST INDIANA.

.DAY ONE...THIS AFTERNOON AND TONIGHT.

  WEATHER HAZARDS EXPECTED:

  THUNDERSTORMS...SOME MAY BE SEVERE AND PRODUCE:

   LOCALLY HEAVY RAINFALL RESULTING IN LOCALIZED FLOODING.
   HAIL UP TO THE SIZE OF QUARTERS
   DAMAGING WINDS UP TO 70 MPH.
   FREQUENT CLOUD TO GROUND LIGHTNING.
   AND POSSIBLY AN ISOLATED TORNADO.

  AREAS AFFECTED AND TIMING:

   A COLD FRONT WILL SWEEP WEST TO EAST ACROSS NORTHERN ILLINOIS
 AND NORTHWEST INDIANA LATE THIS AFTERNOON THROUGH THE EVENING.

  DISCUSSION:

A COLD FRONT WILL SWEEP ACROSS THE REGION THIS EVENING BRINGING
PRIMARILY A THREAT FOR STRONG AND DAMAGING WINDS ALONG WITH A
CONCERN FOR A TORNADO. AHEAD OF THE MAIN LINE OF THUNDERSTORMS...
SCATTERED THUNDERSTORMS ARE POSSIBLE LATE THIS AFTERNOON INTO THE
EARLY EVENING. THE SEVERE WEATHER THREAT SHOULD DIMINISH QUICKLY
BEHIND THE FRONT. IN ADDITION TO THE SEVERE WEATHER THREAT...SOME
AREAS HAVE ALREADY SEEN HEAVY RAIN TODAY WITH SOILS SATURATED.
ADDITIONAL HEAVY RAIN WILL QUICKLY BE CONVERTED TO RUNOFF WITH A
CONCERN FOR AT LEAST LOCALIZED FLOODING.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY.

THERE IS A CHANCE OF THUNDERSTORMS LATE SUNDAY AFTERNOON INTO
SUNDAY NIGHT...AND AGAIN TUESDAY NIGHT THROUGH THURSDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NECESSARY THROUGH TONIGHT.

&&

LMZ740>745-102030-
WINTHROP HARBOR TO WILMETTE HARBOR-
WILMETTE HARBOR TO NORTHERLY ISLAND-
NORTHERLY ISLAND TO CALUMET HARBOR-CALUMET HARBOR TO GARY-
GARY TO BURNS HARBOR-BURNS HARBOR TO MICHIGAN CITY-
328 PM CDT THU APR 9 2015

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE ILLINOIS NEARSHORE
WATERS OF LAKE MICHIGAN AND THE INDIANA NEARSHORE WATERS OF LAKE
MICHIGAN.

.DAY ONE...THIS AFTERNOON AND TONIGHT.

SCATTERED THUNDERSTORMS ARE LIKELY THROUGH LATE THIS EVENING.
SOME THUNDERSTORMS MAY BE SEVERE LATE THIS AFTERNOON AND EARLY
THIS EVENING.

GALE FORCE WINDS ARE EXPECTED LATE THIS EVENING AND OVERNIGHT.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY.

GALE FORCE WINDS ARE LIKELY THROUGH MIDDAY FRIDAY...WITH
WINDS AND WAVES REMAINING HAZARDOUS FOR SMALL CRAFT INTO FRIDAY
EVENING.

THERE IS A CHANCE OF THUNDERSTORMS SUNDAY NIGHT...AND AGAIN
TUESDAY NIGHT THROUGH THURSDAY.

&&

LMZ080-261-362-364-366-563-565-567-669-671-673-675-777-779-868-
870-872-874-876-878-102030-
LAKE MICHIGAN FROM MICHIGAN CITY IN TO ST. JOSEPH MI 5 NM
OFFSHORE TO MID LAKE-
LAKE MICHIGAN FROM SEUL CHOIX POINT TO ROCK ISLAND PASSAGE 5 NM
OFFSHORE TO MID LAKE-
LAKE MICHIGAN SOUTH OF A LINE FROM SEUL CHOIX POINT TO THE
MACKINAC BRIDGE AND NORTH OF A LINE FROM CHARLEVOIX MI TO SOUTH
FOX ISLAND 5 NM OFFSHORE-
LAKE MICHIGAN FROM CHARLEVOIX TO POINT BETSIE MI 5 NM OFFSHORE TO
MID LAKE-
LAKE MICHIGAN FROM POINT BETSIE TO MANISTEE MI 5 NM OFFSHORE TO
MID LAKE-
LAKE MICHIGAN FROM ROCK ISLAND PASSAGE TO STURGEON BAY WI-
LAKE MICHIGAN FROM STURGEON BAY TO TWO RIVERS WI 5 NM OFFSHORE TO
MID LAKE-
LAKE MICHIGAN FROM TWO RIVERS TO SHEBOYGAN WI 5 NM OFFSHORE TO
MID LAKE-
LAKE MICHIGAN FROM SHEBOYGAN TO PORT WASHINGTON WI 5 NM OFFSHORE
TO MID LAKE-
LAKE MICHIGAN FROM PORT WASHINGTON TO NORTH POINT LIGHT WI 5 NM
OFFSHORE TO MID LAKE-
LAKE MICHIGAN FROM NORTH POINT LIGHT TO WIND POINT WI 5 NM
OFFSHORE TO MID LAKE-
LAKE MICHIGAN FROM WIND POINT WI TO WINTHROP HARBOR IL 5 NM
OFFSHORE TO MID LAKE-
LAKE MICHIGAN FROM WINTHROP HARBOR TO WILMETTE HARBOR IL 5 NM
OFFSHORE TO MID LAKE-
LAKE MICHIGAN FROM WILMETTE HARBOR IL TO MICHIGAN CITY IN 5 NM
OFFSHORE TO MID LAKE-
LAKE MICHIGAN FROM PENTWATER TO MANISTEE MI 5 NM OFFSHORE TO MID
LAKE-
LAKE MICHIGAN FROM WHITEHALL TO PENTWATER MI 5 NM OFFSHORE TO MID
LAKE-
LAKE MICHIGAN FROM GRAND HAVEN TO WHITEHALL MI 5 NM OFFSHORE TO
MID LAKE-
LAKE MICHIGAN FROM HOLLAND TO GRAND HAVEN MI 5 NM OFFSHORE TO MID
LAKE-
LAKE MICHIGAN FROM SOUTH HAVEN TO HOLLAND MI 5 NM OFFSHORE TO MID
LAKE-
LAKE MICHIGAN FROM ST. JOSEPH TO SOUTH HAVEN MI 5 NM OFFSHORE TO
MID LAKE-
328 PM CDT THU APR 9 2015

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE OPEN WATERS OF LAKE
MICHIGAN.

.DAY ONE...THIS AFTERNOON AND TONIGHT.

THUNDERSTORMS ARE LIKELY ACROSS MAINLY THE SOUTH HALF OF THE LAKE
INTO THIS EVENING. SOME STORMS COULD BE SEVERE.

GALE FORCE WINDS ARE EXPECTED TONIGHT OVER THE SOUTHERN HALF OF
THE LAKE.

GALE FORCE WINDS ARE EXPECTED OVER THE NORTHERN HALF OF THE LAKE
AFTER MIDNIGHT TONIGHT.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY.

GALE FORCE WINDS ARE LIKELY THROUGH MIDDAY THURSDAY ON THE
SOUTHERN HALF OF THE LAKE.

GALE FORCE WINDS ARE LIKELY THROUGH LATE THURSDAY AFTERNOON ON THE
NORTHERN HALF OF THE LAKE.

THERE IS A CHANCE OF THUNDERSTORMS ON SOUTHERN LAKE MICHIGAN
SUNDAY NIGHT...AND AGAIN TUESDAY NIGHT THROUGH THURSDAY.

&&

BMD/KREIN

VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
643 PM CDT THU APR 09 2015

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0643 PM     TORNADO          CHERRY VALLEY           42.24N 88.96W
04/09/2015                   WINNEBAGO          IL   TRAINED SPOTTER

            CONFIRMED.

&&

B

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
645 PM CDT THU APR 09 2015

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0643 PM     TORNADO          5 SE ASHTON             41.82N 89.15W
04/09/2015                   LEE                IL   TRAINED SPOTTER

            TORNARDO REPORTED DOING DAMAGE NEAR ASHTON. RELAYED BY
            DVN

&&

KBIRK

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
646 PM CDT THU APR 09 2015

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0640 PM     TORNADO          2 NE FRANKLIN GROVE     41.86N 89.27W
04/09/2015                   LEE                IL   TRAINED SPOTTER

            VIEWED FROM I-88. DEBRIS SEEN.

&&

B

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
648 PM CDT THU APR 09 2015

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0645 PM     HAIL             2 E MOUNT MORRIS        42.05N 89.39W
04/09/2015  M1.75 INCH       OGLE               IL   TRAINED SPOTTER

&&

DONOFRIO

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
657 PM CDT THU APR 09 2015

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0645 PM     HAIL             HOFFMAN ESTATES         42.06N 88.14W
04/09/2015  E1.00 INCH       COOK               IL   TRAINED SPOTTER

            AT INTERSECTION OF WESTBURY AND BAYSIDE. HEAVY RAIN.

0650 PM     HAIL             HUNTLEY                 42.17N 88.42W
04/09/2015  E1.00 INCH       MCHENRY            IL   TRAINED SPOTTER

            AT INTERSECTION OF DUNDEE RD AND HALIGHUS.

&&

B

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
703 PM CDT THU APR 09 2015

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0702 PM     TORNADO          5 N HILLCREST           42.02N 89.07W
04/09/2015                   OGLE               IL   TRAINED SPOTTER

            SEVERAL REPORTS OF A LARGE WEDGE TORNADO ON THE GROUND.

&&

KBIRK