River Flood Warning 198, NWS St. Louis, MO

944 
WGUS83 KLSX 201240
FLSLSX
FLOOD STATEMENT 
NATIONAL WEATHER SERVICE ST LOUIS MO
640 AM CST TUE DEC 20 2011

...THE FLOOD WARNING IS CANCELLED FOR THE FOLLOWING RIVER IN 
MISSOURI...
 
  DARDENNE CREEK AT ST. PETERS AFFECTING ST. CHARLES COUNTY

.THIS WILL BE THE LAST STATEMENT FOR THIS EVENT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS PRODUCT ALONG WITH ADDITIONAL WEATHER AND STREAM INFORMATION IS 
AVAILABLE AT HTTP://WWW.CRH.NOAA.GOV/AHPS2/INDEX.PHP?WFO=LSX /LOWER 
CASE/

&&

MOC183-201310-
/O.CAN.KLSX.FL.W.0198.000000T0000Z-111221T1818Z/
/DRCM7.N.ER.000000T0000Z.000000T0000Z.000000T0000Z.UU/
640 AM CST TUE DEC 20 2011

THE FLOOD WARNING IS CANCELLED FOR
  THE DARDENNE CREEK AT ST. PETERS.
* AT  6:00 AM TUESDAY THE STAGE WAS 14.3 FEET. 
* FLOOD STAGE IS 16.0 FEET.
* CRESTED AT 14.35 FEET EARLIER THIS MORNING. 
* FORECAST...THE RIVER WILL CONTINUE TO FALL.

$$

&&
                   FLD   LATEST              7AM FORECAST
LOCATION           STG  OBS STG     12/21  12/22  12/23  12/24  12/25

DARDENNE CREEK
  ST. PETERS      16.0   14.31       9.9    6.0    4.9    4.4    4.1

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
534 PM CST MON DEC 19 2011

.DISCUSSION...
/358 PM CST MON DEC 19 2011/

PRIMARY CONCERN WITH THIS FCST PCKG IS PRECIP CHANCES AND PTYPE FOR
THE NEXT 7 DAYS.

ISENTROPIC ASCENT AHEAD OF A LOW PRESSURE SYSTEM LIFTING NEWD INTO
THE SRN PLAINS WAS PRODUCING A BROAD PCPN SHIELD THIS AFTN THAT
STRETCHED ACROSS MOST OF KS AND MO AND INTO THE SRN HALF OF IL.
AMPLE MOISTURE WILL BE AVAILABLE FOR PCPN WITH MODELS SHOWING A
STRONG LLJ TRANSPORTING A VERY MOIST AIR MASS /PWAT VALUES OF
AROUND 1 INCH WHICH IS 2 STANDARD DEVIATIONS ABOVE NORMAL FOR
DECEMBER IN THIS PART OF THE COUNTRY/ NWD INTO THE REGION. PCPN
SHOULD CONTINUE OVERNIGHT AND INCREASE IN COVERAGE AS THE UPPER
LOW APPROACHES AND LARGE SCALE LIFT INCREASES WITH SOME ADDITIONAL
ENHANCEMENT PROVIDED BY WEAK JET COUPLING. TEMPERATURE PROFILES
CONTINUE TO SUPPORT AN ALL-RAIN EVENT ACROSS ALL BUT THE FAR NRN
CWA WHERE A COLD FRONT WAS EDGING SWD OUT OF IA. THE FAR NRN CWA
WILL BE VERY CLOSE TO THE TRANSITION ZONE BETWEEN RAIN AND SNOW
AND BUFKIT PROFILES AS WELL AS PARTIAL THICKNESS METHODS SUGGEST
THAT SNOW AND SLEET MAY MIX WITH THE RAIN AT TIMES. AS THE SFC LOW
LIFTS OUT OF THE TX PANHANDLE TONIGHT AND TOMORROW...THE BOUNDARY
WILL BE LIFTED NWD AS A WARM FRONT AND PCPN SHOULD CHANGE BACK TO
RAIN. DRY SLOT EFFECTS MAY CAUSE PCPN TO FALL MORE AS DRIZZLE THAN
AS RAIN FOR THE SRN HALF OF THE CWA TOMORROW AND TOMORROW NIGHT.
FINALLY...COLD AIR WRAPPING AROUND THE BACK SIDE OF THE DEPARTING
SYSTEM MAY CAUSE SNOW TO MIX WITH RAIN ACROSS NWRN PARTS OF THE
CWA TOMORROW NIGHT. ATTM IT APPEARS THAT THE DEFORMATION ZONE WILL
REMAIN NORTH AND WEST OF THE CWA. BARRING ANY UNEXPECTED SHIFTS IN
THE TRACK OF THIS SYSTEM...LESS THAN A HALF INCH OF SNOW AND SLEET
ACCUMULATION IS EXPECTED ACROSS THE FAR NRN CWA.

MEANWHILE...WATER VAPOR IMAGERY SHOWED ANOTHER SHORTWAVE DROPPING
SWD ALONG THE CA COAST TOWARDS BAJA CALIFORNIA. MODELS ARE IN GOOD
AGREEMENT THAT THIS SYSTEM CLOSES OFF AND SLOWS DOWN BEFORE MOVING
THROUGH NRN MEXICO AND FINALLY LIFTING THROUGH ERN TX ON WED/THU IN
RESPONSE TO THE STRONGER SHORTWAVE REACHING THE WA/OR COAST ON TUE
NIGHT. THE SHORTWAVE CURRENTLY ALONG THE CA COAST IS NOT EXPECTED TO
PRODUCE ANY PCPN FOR OUR AREA AS IT LIFTS THROUGH THE SRN CONUS.
HOWEVER...MODELS SHOW THAT THE OTHER SYSTEM DEEPENS AFTER CROSSING
THE ROCKIES AND TAKES A TRACK THAT WOULD BE FAVORABLE FOR SNOWFALL
ACROSS MOST OF THE CWA. THERE ARE STILL SIGNIFICANT DIFFERENCES
BETWEEN THE GFS/ECMWF/GEM /ESPECIALLY WRT PHASING WITH NRN STREAM
SHORTWAVES/ AND BETTER MODEL AGREEMENT MIGHT NOT OCCUR UNTIL AFTER
THESE FEATURES HAVE BEEN SAMPLED BY THE UPPER AIR NETWORK.

KANOFSKY

&&

.AVIATION...
/512 PM CST MON DEC 19 2011/

RA IS EXPECTED TO CONTINUE THRU MUCH OF THE TAF PERIOD AS A STORM
SYSTEM APPROACHES THE REGION. VSBYS ARE EXPECTED TO REMAIN IN THE
LOW MVFR RANGE WITH CIGS EXPECTED TO LOWER TO AND REMAIN IN THE
IFR RANGE THRU MUCH OF THE PERIOD. WINDS ARE EXPECTED TO BE NLY AS
WRMFNT SETTLES JUST S OF TERMINALS. MAY SEE SOME IMPROVEMENT LATE
TUES AFTERNOON AS DRY SLOT MOVES INTO THE REGION. HOWEVER...THIS
IMPROVEMENT IS EXPECTED TO BE SHORT LIVED AS CIGS MAY DROP BACK
INTO THE IFR RANGE AS THE SFC LOW APPROACHES.

SPECIFICS FOR KSTL...RA IS EXPECTED TO CONTINUE THRU MUCH OF THE
TAF PERIOD AS A STORM SYSTEM APPROACHES THE REGION. VSBYS ARE
EXPECTED TO REMAIN IN THE LOW MVFR RANGE WITH CIGS EXPECTED TO
LOWER TO AND REMAIN IN THE IFR RANGE THRU MUCH OF THE PERIOD.
WINDS ARE EXPECTED TO BE NLY AS WRMFNT SETTLES JUST S OF
TERMINAL. MAY SEE SOME IMPROVEMENT LATE TUES AFTERNOON AS DRY
SLOT MOVES INTO THE REGION. HOWEVER...THIS IMPROVEMENT IS EXPECTED
TO BE SHORT LIVED AS CIGS MAY DROP BACK INTO THE IFR RANGE AS THE
SFC LOW APPROACHES.

TILLY

&&

.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&

WFO LSX

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE ST LOUIS MO
358 PM CST MON DEC 19 2011

ILZ058>060-064-065-069-070-074-079-095>102-MOZ018-019-026-027-
034>036-041-042-047>052-059>065-072>075-084-085-099-201115-
GREENE IL-MACOUPIN IL-MONTGOMERY IL-BOND IL-FAYETTE IL-CLINTON IL-
MARION IL-WASHINGTON IL-RANDOLPH IL-ADAMS IL-BROWN IL-PIKE IL-
CALHOUN IL-JERSEY IL-MADISON IL-ST. CLAIR IL-MONROE IL-KNOX MO-
LEWIS MO-SHELBY MO-MARION MO-MONROE MO-RALLS MO-PIKE MO-BOONE MO-
AUDRAIN MO-MONITEAU MO-COLE MO-OSAGE MO-CALLAWAY MO-MONTGOMERY MO-
LINCOLN MO-GASCONADE MO-WARREN MO-ST. CHARLES MO-FRANKLIN MO-
ST. LOUIS MO-ST. LOUIS CITY MO-JEFFERSON MO-CRAWFORD MO-
WASHINGTON MO-ST. FRANCOIS MO-STE. GENEVIEVE MO-IRON MO-
MADISON MO-REYNOLDS MO-
358 PM CST MON DEC 19 2011

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF EASTERN AND
CENTRAL MISSOURI AS WELL AS WEST CENTRAL AND SOUTHWEST ILLINOIS.

.DAY ONE...TONIGHT

A WINTRY MIX OF RAIN...SNOW...AND SLEET IS LIKELY FOR PARTS OF
NORTHEAST MISSOURI AND WEST CENTRAL ILLINOIS LATE TONIGHT. A FEW
TENTHS OF AN INCH OF SNOW AND SLEET IS EXPECTED IN THIS AREA.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

A WINTRY MIX OF RAIN AND SNOW IS LIKELY FOR PARTS OF CENTRAL AND
NORTHEAST MISSOURI AS WELL AS WEST CENTRAL ILLINOIS LATE TUESDAY
NIGHT WITH PRECIPITATION LINGERING INTO WEDNESDAY MORNING. AROUND
A TENTH OF AN INCH OF SNOW IS POSSIBLE.

.SPOTTER INFORMATION STATEMENT...

SPOTTERS ARE ENCOURAGED TO RELAY SLEET AND SNOWFALL REPORTS TO THE
NATIONAL WEATHER SERVICE.

KANOFSKY