HYDROLOGIC OUTLOOK
Issue Date: 902 PM CST TUE DEC 22 2009
Expiration: 915 AM CST WED DEC 23 2009

/1002 PM EST TUE DEC 22 2009/
...RENEWED RISES ON AREA RIVERS POSSIBLE LATER THIS WEEK...
A VERY STRONG LOW WILL MOVE INTO NORTHEAST IOWA BY FRIDAY
MORNING. THIS WILL BRING A MIXTURE OF PRECIPITATION
TONIGHT...WEDNESDAY AND THURSDAY INTO NORTHERN ILLINOIS AND
NORTHWEST INDIANA. THE PRECIPITATION WILL BEGIN AS SNOW AND SLEET
OVERNIGHT AND WILL CHANGE TO FREEZING DRIZZLE. WE EXPECT FREEZING
RAIN WEDNESDAY NIGHT AND EARLY THURSDAY MORNING. THEN...RAIN WILL
FALL OVER THE AREA THURSDAY. THERE IS SNOW ON THE GROUND AND THE
ADDITIONAL 1 TO 2 INCHES OF RAIN WITH SNOWMELT WILL ADD SIGNIFICANT
RUNOFF TO AREA RIVERS. SOME LOCAL RIVERS AND CREEKS MAY RISE
THURSDAY AND FRIDAY.
SNOW DEPTHS WERE GREATEST WITHIN PORTIONS OF THE ROCK...UPPER
FOX...AND UPPER DES PLAINES RIVER BASINS WHERE DEPTHS WERE BETWEEN 4
AND 8 INCHES. WATER EQUIVALENT OF THE SNOWPACK IN THOSE AREAS WAS
AROUND 1 INCH. FURTHER SOUTH...SNOW DEPTHS WERE BETWEEN 2 AND 4
INCHES WITH WATER EQUIVALENTS GENERALLY BELOW ONE HALF INCH.
REPORTED FROST DEPTHS WERE BETWEEN 2 AND 4 INCHES. ALTHOUGH RIVERS
WERE CURRENTLY BELOW FLOOD STAGE...FLOWS WERE SLIGHTLY ABOVE
NORMAL.
A COMBINATION OF HEAVY RAIN AND SNOWMELT OVER FROZEN GROUND WOULD
RESULT IN RISES ON AREA STREAMS WITH SOME RISES POSSIBLY ABOVE FLOOD
STAGE.
RESIDENTS IN LOW LYING FLOOD PRONE AREAS ALONG AREA RIVERS AND
CREEKS SHOULD CONTINUE TO MONITOR THIS DEVELOPING WEATHER SYSTEM.
$$

HAZARDOUS WEATHER OUTLOOK
Issue Date: 524 AM CST WED DEC 23 2009
Expiration: 515 AM CST THU DEC 24 2009

/613 AM EST WED DEC 23 2009/
THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTH CENTRAL ILLINOIS...
NORTHEAST ILLINOIS AND NORTHWEST INDIANA.
.DAY ONE...TODAY AND TONIGHT.
FREEZING DRIZZLE AND SLEET...POSSIBLY MIXED WITH SNOW WILL
DEVELOP OVER PORTIONS OF NORTHWEST INDIANA THIS MORNING...AND
CONTINUE INTO THIS EVENING BEFORE CHANGING TO RAIN.
MIXED PRECIPITATION IS ALSO EXPECTED TO BECOME MORE WIDESPREAD
ACROSS MUCH OF NORTHERN ILLINOIS TODAY. SURFACE TEMPERATURES
OVER NORTHERN ILLINOIS WILL STAY AT OR JUST BELOW FREEZING
GENERALLY ALONG AND NORTH OF INTERSTATE 88...AND WEST OF THE CITY
OF CHICAGO. ICE ACCUMULATIONS OF UP TO A QUARTER INCH ARE EXPECTED
IN THESE AREAS BY THURSDAY MORNING.
SURFACE TEMPERATURES ARE EXPECTED TO WARM ABOVE FREEZING BY MIDDAY
THURSDAY...RESULTING IN A CHANGE OVER TO ALL RAIN OVER THE ENTIRE
FORECAST AREA.
.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY.
A MORE SUBSTANTIAL AREA OF PRECIPITATION IS EXPECTED TO OVERSPREAD
THE AREA THURSDAY AFTERNOON AND CONTINUE MUCH OF THURSDAY NIGHT.
BY THIS TIME...PRECIPITATION WILL BE ENTIRELY IN THE FORM OF RAIN.
GIVEN THE POTENTIALLY HEAVY RAINFALL...COMBINED WITH MELTING SNOW
AND FROZEN GROUND...FLOODING OF RIVERS AND LOW LYING AREAS
APPEARS LIKELY.
COLDER AIR WILL THEN CIRCULATE AROUND THE STORM CENTER ALLOWING
PRECIPITATION TO CHANGE BACK TO LIGHT SNOW OR SNOW SHOWERS ON
CHRISTMAS DAY...WITH PERIODS OF LIGHT SNOW CONTINUING INTO SUNDAY
AS THE LOW CENTER DRIFTS OFF ACROSS THE MIDWEST.
WINTER WEATHER ADVISORIES ARE NOW IN EFFECT FOR PORTIONS OF THE
OUTLOOK AREA. PLEASE REFERENCE THE LATEST WINTER WEATHER
STATEMENTS FROM THE NATIONAL WEATHER SERVICE FOR THE LATEST
FORECAST INFORMATION.
A FLOOD WATCH HAS ALSO BEEN ISSUED FOR THE OUTLOOK AREA.
THIS STORM SYSTEM HAS THE POTENTIAL TO IMPACT TRAVEL DURING THE
CHRISTMAS HOLIDAY PERIOD. PERSONS PLANNING TRAVEL ACROSS THE
MIDWEST BETWEEN WEDNESDAY AND SATURDAY SHOULD MONITOR FURTHER
FORECASTS AND STATEMENTS FOR THE LATEST INFORMATION ON THIS
INTENSIFYING WINTER STORM.
.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION WILL NOT BE NECESSARY THROUGH TONIGHT.
&&
COMPLETE FORECAST INFORMATION IS AVAILABLE ON THE NWS CHICAGO
WEBPAGE: WEATHER.GOV/CHICAGO
$$

WINTER WEATHER ADVISORY
Issue Date: 406 AM CST WED DEC 23 2009
Expiration: 1200 PM CST THU DEC 24 2009

...A WINTRY MIX OF PRECIPITATION WILL DEVELOP OVER NORTHERN
ILLINOIS AND NORTHWEST INDIANA TODAY...
.A DEVELOPING WINTER STORM OVER THE SOUTHERN PLAINS WILL MOVE
NORTH TO IOWA BY FRIDAY MORNING. A PERIOD OF WINTRY PRECIPITATION
IS EXPECTED TO DEVELOP ACROSS THE REGION TODAY...THEN TRANSITION
TO RAIN FROM SOUTH TO NORTH TONIGHT INTO THURSDAY MORNING.
ILZ003>006-008-010>012-231815-
/O.UPG.KLOT.WS.A.0004.091223T1800Z-091224T1800Z/
/O.EXB.KLOT.WW.Y.0014.091223T1800Z-091224T1800Z/
WINNEBAGO-BOONE-MCHENRY-LAKE IL-OGLE-LEE-DE KALB-KANE-
INCLUDING THE CITIES OF...ROCKFORD...BELVIDERE...WOODSTOCK...
WAUKEGAN...OREGON...DIXON...DEKALB...AURORA
406 AM CST WED DEC 23 2009
...WINTER WEATHER ADVISORY IN EFFECT FROM NOON TODAY TO NOON CST
THURSDAY...
THE NATIONAL WEATHER SERVICE IN CHICAGO HAS ISSUED A WINTER
WEATHER ADVISORY FOR A MIXTURE OF FREEZING RAIN AND SLEET...
WHICH IS IN EFFECT FROM NOON TODAY TO NOON CST THURSDAY. THE
WINTER STORM WATCH IS NO LONGER IN EFFECT.
* TIMING...A MIXTURE OF FREEZING RAIN...SLEET AND SNOW IS EXPECTED
TO DEVELOP THIS AFTERNOON AND CONTINUE THROUGH THURSDAY MORNING.
AS TEMPERATURES WARM ABOVE FREEZING THURSDAY MORNING...THE
PRECIPITATION WILL TRANSITION TO RAIN.
* ACCUMULATIONS...SNOW AND SLEET ACCUMULATIONS LESS THAN ONE INCH.
ICE ACCUMULATION OF UP TO ONE QUARTER INCH.
* HAZARDS...ACCUMULATION OF ICE.
* IMPACTS...GLAZING OF ROADWAYS...PARKING LOTS AND SIDEWALKS. THIS
WILL MAKE FOR HAZARDOUS TRAVEL ON UNTREATED SURFACES.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
A WINTER WEATHER ADVISORY MEANS THAT A COMBINATION OF SNOW...
SLEET...OR FREEZING RAIN WILL RESULT IN SLIPPERY ROADWAYS AND
CAUSE TRAVEL DIFFICULTIES. BE PREPARED FOR HAZARDOUS DRIVING
CONDITIONS AND USE CAUTION WHILE TRAVELING.
$$

FLOOD WATCH
Issue Date: 345 AM CST WED DEC 23 2009
Expiration: 600 AM CST FRI DEC 25 2009

...HEAVY RAIN AND FLOODING POSSIBLE THURSDAY AFTERNOON THROUGH
FRIDAY MORNING...
.A DEVELOPING WINTER STORM OVER THE SOUTHERN PLAINS WILL MOVE
NORTH TO IOWA BY FRIDAY MORNING. AFTER A PERIOD OF WINTRY
PRECIPITATION WEDNESDAY AFTERNOON INTO THURSDAY MORNING...WARM
MOIST AIR WILL SPREAD NORTH ACROSS THE AREA WITH PERIODS OF
HEAVY RAIN EXPECTED THURSDAY AFTERNOON AND THURSDAY NIGHT.
ILZ003>006-008-010>014-019>023-032-033-039-INZ001-002-010-011-019-
231745-
/O.NEW.KLOT.FA.A.0003.091224T1800Z-091225T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
WINNEBAGO-BOONE-MCHENRY-LAKE IL-OGLE-LEE-DE KALB-KANE-DUPAGE-COOK-
LA SALLE-KENDALL-GRUNDY-WILL-KANKAKEE-LIVINGSTON-IROQUOIS-FORD-
LAKE IN-PORTER-NEWTON-JASPER-BENTON-
INCLUDING THE CITIES OF...ROCKFORD...BELVIDERE...WOODSTOCK...
WAUKEGAN...OREGON...DIXON...DEKALB...AURORA...WHEATON...CHICAGO...
OTTAWA...OSWEGO...MORRIS...JOLIET...KANKAKEE...PONTIAC...
WATSEKA...PAXTON...GARY...VALPARAISO...MOROCCO...RENSSELAER...
FOWLER
345 AM CST WED DEC 23 2009 /445 AM EST WED DEC 23 2009/
...FLOOD WATCH IN EFFECT FROM THURSDAY AFTERNOON THROUGH LATE
THURSDAY NIGHT...
THE NATIONAL WEATHER SERVICE IN CHICAGO HAS ISSUED A
* FLOOD WATCH FOR PORTIONS OF ILLINOIS AND INDIANA...INCLUDING
THE FOLLOWING AREAS...IN ILLINOIS...BOONE...COOK...DE KALB...
DUPAGE...FORD...GRUNDY...IROQUOIS...KANE...KANKAKEE...
KENDALL...LA SALLE...LAKE IL...LEE...LIVINGSTON...MCHENRY...
OGLE...WILL AND WINNEBAGO. IN INDIANA...BENTON...JASPER...LAKE
IN...NEWTON AND PORTER.
* FROM THURSDAY AFTERNOON THROUGH LATE THURSDAY NIGHT.
* HEAVY RAIN IS EXPECTED TO DEVELOP ACROSS NORTHERN ILLINOIS AND
NORTHWEST INDIANA BY THURSDAY AFTERNOON AND CONTINUE THROUGH
EARLY FRIDAY MORNING. STORM TOTAL RAINFALL AMOUNTS OF 1 TO 2
INCHES WILL BE COMMON. SOME AREAS MAY RECEIVE AS MUCH AS 3
INCHES BY FRIDAY MORNING.
* THE DEPTH OF THE CURRENT SNOW PACK RANGES FROM 5 TO 8 INCHES
OVER NORTHWEST ILLINOIS TO 1 TO 3 INCHES ACROSS NORTHWEST
INDIANA. AS THIS SNOW MELTS...COMBINED WITH THE EXPECTED HEAVY
RAIN...AND FROZEN GROUND CONDITIONS...RAPID RUNOFF AND RISES ON
AREA RIVERS ARE EXPECTED. SOME RIVERS MAY REACH OR EXCEED FLOOD
STAGE. FLOODING OF LOW LYING AND FLOOD PRONE AREAS WILL ALSO BE
POSSIBLE.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
A FLOOD WATCH MEANS THERE IS A POTENTIAL FOR FLOODING BASED ON
CURRENT FORECASTS.
YOU SHOULD MONITOR LATER FORECASTS AND BE ALERT FOR POSSIBLE
FLOOD WARNINGS. THOSE LIVING IN AREAS PRONE TO FLOODING SHOULD BE
PREPARED TO TAKE ACTION SHOULD FLOODING DEVELOP.
$$

WINTER STORM WATCH
Issue Date: 1131 AM CST TUE DEC 22 2009
Expiration: 1200 PM CST THU DEC 24 2009

...WINTER STORM TO BRING SLEET AND FREEZING RAIN TO AREA WEDNESDAY
INTO THURSDAY...
.LOW PRESSURE ASSOCIATED WITH A DEVELOPING WINTER STORM WILL LIFT
FROM THE SOUTHERN PLAINS INTO THE MISSISSIPPI VALLEY THROUGH
THURSDAY. WHILE THE TRACK OF THE STORM WILL KEEP HEAVY SNOWS WEST
OF THE AREA...WARM MOIST AIR FLOWING NORTH ACROSS NORTHERN ILLINOIS
AND INDIANA WILL RIDE UP OVER COLD AIR NEAR THE GROUND...AND IS
EXPECTED TO RESULT IN A PERIOD OF SLEET AND FREEZING RAIN FROM
WEDNESDAY INTO THURSDAY MORNING. FREEZING RAIN MAY RESULT IN UP
TO A QUARTER INCH OF ICE ACCUMULATION OVER PARTS OF THE WATCH AREA
ESPECIALLY LATE WEDNESDAY AND WEDNESDAY NIGHT. SURFACE
TEMPERATURES WILL THEN RISE ABOVE FREEZING FROM SOUTH TO NORTH BY
MIDDAY THURSDAY...WITH PRECIPITATION CHANGING TO RAIN OVER THE
AREA BY THURSDAY AFTERNOON.
ILZ003>006-008-010>014-019>023-INZ001-002-010-011-230145-
/O.NEW.KLOT.WS.A.0004.091223T1800Z-091224T1800Z/
WINNEBAGO-BOONE-MCHENRY-LAKE IL-OGLE-LEE-DE KALB-KANE-DUPAGE-COOK-
LA SALLE-KENDALL-GRUNDY-WILL-KANKAKEE-LAKE IN-PORTER-NEWTON-
JASPER-
INCLUDING THE CITIES OF...ROCKFORD...BELVIDERE...WOODSTOCK...
WAUKEGAN...OREGON...DIXON...DEKALB...AURORA...WHEATON...CHICAGO...
OTTAWA...OSWEGO...MORRIS...JOLIET...KANKAKEE...GARY...
VALPARAISO...MOROCCO...RENSSELAER
1131 AM CST TUE DEC 22 2009
...WINTER STORM WATCH IN EFFECT FROM WEDNESDAY AFTERNOON THROUGH
THURSDAY MORNING...
THE NATIONAL WEATHER SERVICE IN CHICAGO HAS ISSUED A WINTER STORM
WATCH...WHICH IS IN EFFECT FROM WEDNESDAY AFTERNOON THROUGH
THURSDAY MORNING.
* TIMING...LIGHT SLEET AND FREEZING RAIN WILL BEGIN DURING THE DAY
WEDNESDAY. HEAVIEST FREEZING RAIN IS EXPECTED FROM WEDNESDAY
EVENING INTO THURSDAY MORNING.
* ACCUMULATIONS...UP TO A QUARTER INCH OF ICE.
* HAZARDS...ACCUMULATION. SOME SLEET AND LIGHT SNOW MAY MIX AS
PRECIPITATION BEGINS ON WEDNESDAY.
* IMPACTS...GLAZING OF ROADWAYS...PARKING LOTS AND SIDEWALKS. THIS
WILL MAKE FOR HAZARDOUS TRAVEL ON UNTREATED SURFACES.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
A WINTER STORM WATCH MEANS THERE IS A POTENTIAL FOR SIGNIFICANT
SNOW...SLEET...OR ICE ACCUMULATIONS THAT MAY IMPACT TRAVEL.
CONTINUE TO MONITOR THE LATEST FORECASTS.
$$
RATZER