River Flood Warning 202, NWS St. Louis, MO

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
631 AM CDT WED JUN 16 2010

.DISCUSSION...
/352 AM CDT WED JUN 16 2010/

COLD FRONT HAS PUSHED SOUTH OF THE AREA ALTHOUGH RECENT SATELLITE
IMAGERY AND THETA-E ANALYSIS SUGGEST A SECONDARY FNTL BDRY COULD BE
LINGERING ACROSS MISSOURI ALONG THE INTERSTATE 70 CORRIDOR. TODAY
LOOKS LIKE THE COOLEST DAY OUT OF THE NEXT SEVERAL DAYS AS HIGH
PRESSURE BEGINS BUILDING IN AT THE SFC AND ALOFT. AS THE SFC HIGH
SHIFTS SEWD...WINDS WILL TURN SLY TO SWLY BY TOMORROW AND ADVECT A
WARM AND MOIST AIR MASS BACK INTO THE REGION. AT THE SAME TIME...A
WARM FRONT WILL LIFT NEWD THROUGH MO/IL ON THU WITH H85 TEMPERATURES
GRADUALLY RISING TO +18 TO +22 DEG C BY FRIDAY AFTERNOON. GIVEN
LIMITED CLOUD COVER...THESE FACTORS SUPPORT HIGHS IN THE UPPER 80S
TO MID 90S FROM TOMORROW THROUGH SAT WITH HEAT INDICES REACHING 100
DEGREES ON FRIDAY ACROSS THE CWA. VERY FEW CHANGES MADE TO GOING
TEMPERATURE FCST SINCE IT ALREADY REFLECTS THESE TRENDS.

A LARGE LOW PRESSURE SYSTEM WILL REMAIN WELL NORTH AND WEST OF MO/IL
AS IT MOVES THROUGH THE NRN PLAINS HOWEVER SHORTWAVES ROTATING
AROUND THE PERIPHERY OF THE SYSTEM COULD PROVIDE FORCING FOR TSRA.
LOCAL WRF MODEL DEPICTS AN ELONGATED AREA OF STRONG MCONV TONIGHT
ACROSS SWRN IA INTO NRN MO THAT SHIFTS NEWD WITH TIME. HAVE KEPT
SCHC POPS FOR TONIGHT GIVEN UNCERTAINTY ON WHETHER CONVECTION WILL
DVLP. MODELS SUGGEST THAT THIS SYSTEM WILL LAY OUT AN E-W ORIENTED
FNTL BDRY SOMEWHERE ACROSS IA OVER THE WEEKEND AS THE UPPER LEVEL
LOW LIFTS INTO CANADA. THE SWD EXTENT OF THIS BDRY WILL HAVE TO BE
WATCHED SINCE IT COULD PROVIDE A FOCUS FOR SHRA/TSRA OVER THE
WEEKEND GIVEN ITS LOCATION BELOW THE RIGHT ENTRANCE REGION OF A
H5 JET. NO CHANGES PAST 12Z SUN.

KANOFSKY

&&

.AVIATION...
/621 AM CDT WED JUN 16 2010/

THERE IS DENSE FOG REDUCING VSBYS TO 1/4SM EARLY THIS MORNING IN
LOW LYING AREAS. KSUS WAS DOWN THIS LOW AN HOUR AGO...BUT HAS
ALREADY IMPROVED TO 10SM WITH ONLY SOME MINOR HAZE SEEN ON LOCAL
WEBCAMS. REMAINING FOG SHOULD BURN OFF QUICKLY BY 14Z. THERE IS A
SLIGHT CHANCE OF TSRA LATE TONIGHT OVER CNTRL MO AS A WARM FRONT
MOVES BACK NEWD...BUT CHANCE IS TOO LOW TO INCLUDE IN THE KCOU TAF
AT THIS TIME. OTHERWISE...DRY AND VFR CONDITIONS EXPECTED THROUGH
END OF PERIOD.

SPECIFICS FOR KSTL...HIGH PRESSURE MOVING EWD ACROSS MO WILL BRING
DRY AND VFR WEATHER WITH LGT/VRB WINDS NEXT 30 HOURS.

BRITT

&&

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

WFO LSX

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE ST LOUIS MO
432 AM CDT WED JUN 16 2010

ILZ058>060-064-065-069-070-074-079-095>102-MOZ018-019-026-027-
034>036-041-042-047>052-059>065-072>075-084-085-099-170945-
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-
432 AM CDT WED JUN 16 2010

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

.DAY ONE...TODAY AND TONIGHT

THERE IS A SLIGHT CHANCE OF THUNDERSTORMS TONIGHT ACROSS PARTS OF
MISSOURI AND ILLINOIS. SEVERE WEATHER IS NOT EXPECTED AT THIS
TIME.

MODERATE RIVER FLOODING IS OCCURRING ALONG PORTIONS OF THE
MISSISSIPPI RIVER. PLEASE SEE THE APPROPRIATE FLOOD WARNING
OR FLOOD STATEMENT FOR SPECIFIC DETAILS.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

THERE IS A CHANCE OF THUNDERSTORMS ON FRIDAY AS A COLD FRONT
MOVES THROUGH THE AREA.

HEAT INDEX VALUES WILL APPROACH 100 DEGREES ON FRIDAY ACROSS THE
AREA. HEAT INDEX VALUES NEAR 100 DEGREES ARE ALSO POSSIBLE FROM
SATURDAY THROUGH MONDAY...PARTICULARLY IN THE ST. LOUIS
METROPOLITAN AREA.

MODERATE RIVER FLOODING IS FORECAST ALONG PORTIONS OF THE
MISSOURI AND MISSISSIPPI RIVERS. PLEASE SEE THE APPROPRIATE FLOOD
WARNING OR FLOOD STATEMENT FOR SPECIFIC DETAILS.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED THROUGH TONIGHT.

&&

FOR A GRAPHICAL VERSION OF THIS INFORMATION SEE OUR
WEBPAGE AT (LOWERCASE)... HTTP://WWW.WEATHER.GOV/LSX/?N=HWO1

KANOFSKY