HYDROLOGIC OUTLOOK
Issue Date: 259 PM CST MON DEC 21 2009
Expiration: 530 AM CST TUE DEC 22 2009

...SIGNIFICANT RAINFALL AND SNOW MELT POSSIBLE WEDNESDAY AND THURSDAY...
AN UNSEASONABLY STRONG SURGE OF MOISTURE IS EXPECTED INTO THE
STATE ON WEDNESDAY AND THURSDAY. THIS IS FORECAST TO PUSH
TEMPERATURES ABOVE FREEZING BY WEDNESDAY AFTERNOON...PRIMARILY
ALONG AND SOUTH OF INTERSTATE 80. THEREFORE...RAIN IS THE PRIMARY
PRECIPITATION TYPE EXPECTED ACROSS THE SOUTHERN THIRD TO HALF OF
CENTRAL IOWA WEDNESDAY AFTERNOON INTO THURSDAY. BETWEEN THREE-
QUARTERS AND AN INCH AND A HALF OF RAIN IS FORECAST DURING THIS
TIME. IN ADDITION...THE SNOW ON THE GROUND CONTAINS AROUND AN INCH
TO INCH AND A HALF OF WATER. THE COMBINATION OF THE RAINFALL AND
SNOW MELT WILL LEAD TO LARGE AMOUNTS OF RUNOFF.
TEMPERATURES WILL BE THE BIG FACTOR IN THE EFFICIENCY OF THE
RUNOFF FROM SNOW MELT. SHOULD READING STAY JUST ABOVE
FREEZING...SNOW MELT WILL NOT BE AS QUICK AND RUNOFF WILL BE
MUTED. HOWEVER...SHOULD TEMPERATURES REACH 40 OR HIGHER...THEN
SNOW MELT WILL BE MUCH FASTER WITH A BIGGER RESPONSE IN RUNOFF.
AREA STREAMS AND RIVERS ACROSS THE SOUTHERN HALF OF IOWA WILL
LIKELY EXPERIENCE LARGE RISES DUE TO THE COMBINATION OF RAINFALL
AND SNOW MELT BY THURSDAY AND RIVER FLOODING MAY BECOME
PROBLEMATIC. BASINS WHICH APPEAR MOST LIKELY TO BE AFFECTED
INCLUDE THE CHARITON...LOWER DES MOINES...SOUTH SKUNK...CEDAR
CREEK...AND THE THOMPSON RIVERS ACROSS THE SOUTHERN HALF OF
CENTRAL IOWA.
$$
COGIL

HAZARDOUS WEATHER OUTLOOK
Issue Date: 1153 PM CST MON DEC 21 2009
Expiration: 1200 AM CST WED DEC 23 2009

Expires:200912230600;;
FLUS43 KDMX 220553
HWODMX
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE DES MOINES IA
1153 PM CST MON DEC 21 2009
IAZ061-062-072>075-081>086-092>097-230600-
JASPER-POWESHIEK-MADISON-WARREN-MARION-MAHASKA-ADAMS-UNION-CLARKE-
LUCAS-MONROE-WAPELLO-TAYLOR-RINGGOLD-DECATUR-WAYNE-APPANOOSE-DAVIS-
1153 PM CST MON DEC 21 2009
THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTH CENTRAL
IOWA.
.DAY ONE...TONIGHT
NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.
.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY
A MAJOR WINTER STORM WILL AFFECT THE AREA ON WEDNESDAY THROUGH
FRIDAY. FREEZING DRIZZLE WILL INITIALLY BE WIDESPREAD ON TUESDAY
INTO TUESDAY NIGHT WITH MORE SIGNIFICANT PRECIPITATION SPREADING
INTO CENTRAL IOWA ON WEDNESDAY. A MIXTURE OF PRECIPITATION IS
EXPECTED INITIALLY WITH THE HEAVIER PRECIPITATION BUT WARMER AIR
HEADING INTO IOWA SHOULD HELP TRANSITION MUCH OF THE MIXTURE TO
RAIN BY WEDNESDAY AFTERNOON. THE RAIN WILL PERSIST ACROSS MUCH OF
THE AREA THROUGH THURSDAY PRIOR TO A GRADUAL TRANSITION BACK TO
ALL SNOW BY FRIDAY. SOME MINOR TO MODERATE ACCUMULATIONS ARE
EXPECTED FROM THIS SNOW. RIVER FLOODING MAY ALSO BECOME
PROBLEMATIC DUE TO THE RAINFALL AND SNOW MELT.
.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION WILL NOT BE NECESSARY...HOWEVER RAINFALL
REPORTS OR OTHER ADVERSE WEATHER REPORTS ARE APPRECIATED AND ENCOURAGED.
$$