River Flood Warning 226, NWS St. Louis, MO

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
558 AM CST SAT DEC 26 2015

.SHORT TERM: (Through Tonight)
Issued at 245 AM CST Sat Dec 26 2015

Confidence continues to increase that a high impact and
potentially historic flooding event will unfold this afternoon
through Monday. Life threatening flash flooding along
creeks/streams and other low lying areas is expected, along with
major to historic flooding on area rivers. The forecast itself has
not changed much at all with widespread rainfall amounts of 4-8
inches across the southeast half of the CWA. There was a slight
northwest adjustment to the heaviest axis of rainfall in the 00Z
guidance, but this did not impact headlines.

Showers and thunderstorms are quickly developing to our southwest
and advecting northeast toward the CWA as the warm front begins to
lift north. Believe coverage will become widespread by this
afternoon as a perfect recipe for heavy rainfall aligns overhead.
Key feature is a back building anticyclonically curved upper level
jet that will enduce an ageostrophic response, increasing
frontogenesis and therefore upward vertical motion. The focused
forcing and flow aloft parallel to the frontal zone, favors training
convection. Can't rule a few strong or severe storms occuring this
afternoon and evening along and south of the front as well. The
heaviest rainfall from this prolonged event will occur from this
afternoon through Sunday morning with a broad area of 3 to 5 inches
occurring.  The convective nature of this precipitation could
produce locally higher amounts, especially if training persists.

CVKING

.LONG TERM: (Sunday through Friday)
Issued at 245 AM CST Sat Dec 26 2015

The front should sag south on Sunday, shifting the axis of
heaviest rainfall to the southern third of the CWA.

The final wave of potentially heavy rainfall will occur Sunday night
into Monday as a strong closed upper low and the associated
vertically stacked system lifts north/northeast through the middle
Mississippi River Valley. Due to the warm air aloft and track of the
system, believe the prospect of any wintry preciptiation remains
very low. Generally have painted another 1 to 3 inches of rain with
the system itself to come up with event total rainfall amounts of 4
to 8 inches.

Remainder of the forecast features sensible weather more
representative of winter with cold temperatures and a chance of
some light snow on Wednesday.

CVKING

&&

.AVIATION:  (For the 12z TAFs through 12z Sunday Morning)
Issued at 546 AM CST Sat Dec 26 2015

IFR flight conditions in rain, thunderstorms, and fog will
overspread the area today. Expect IFR flight conditions to prevail
through the end of the forecast period with ceilings and
visibilities occasionally dropping below airport minimums in
heavy rain...especially along and south of the I-70 corridor.
Flight conditions below minimums may be reached across northeast
Missouri and west central Illinois as well, but more for low
ceilings and fog rather than heavy rain.

Specifics for KSTL:

Areal coverage of rain and thunderstorms in the STL metro area
will increase as the day progresses. Expect ceilings and
visibilities to lower to IFR and possibly below alternate minimums
by mid to late morning. Once ceilings drop to IFR...expect IFR
flight conditions with moderate to occasional heavy rain to
prevail through the end of the forecast period. Could see
ceilings/vsibilities occasionally drop below airport minimums.

Carney

&&

.PRELIMINARY POINT TEMPS/POPS:
Saint Louis     58  42  44  40 / 100 100 100 100
Quincy          47  36  39  35 /  90  90  70  90
Columbia        51  37  39  37 / 100 100 100 100
Jefferson City  53  39  40  38 / 100 100 100 100
Salem           64  47  50  42 / 100 100 100 100
Farmington      65  45  48  42 / 100 100 100 100

&&

.LSX WATCHES/WARNINGS/ADVISORIES:
MO...Flash Flood Watch from noon CST today through Monday afternoon
     FOR Audrain MO-Boone MO-Callaway MO-Cole MO-Crawford MO-
     Franklin MO-Gasconade MO-Iron MO-Jefferson MO-Lincoln MO-
     Madison MO-Moniteau MO-Monroe MO-Montgomery MO-Osage MO-
     Pike MO-Ralls MO-Reynolds MO-St. Charles MO-St. Francois MO-
     St. Louis City MO-St. Louis MO-Ste. Genevieve MO-Warren MO-
     Washington MO.

IL...Flash Flood Watch from noon CST today through Monday afternoon
     FOR Bond IL-Calhoun IL-Clinton IL-Fayette IL-Greene IL-
     Jersey IL-Macoupin IL-Madison IL-Marion IL-Monroe IL-
     Montgomery IL-Pike IL-Randolph IL-St. Clair IL-Washington
     IL.

&&

WFO LSX

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE ST LOUIS MO
307 AM CST SAT DEC 26 2015

ILZ058>060-064-065-069-070-074-079-095>102-MOZ018-019-026-027-
034>036-041-042-047>052-059>065-072>075-084-085-099-271200-
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-
307 AM CST SAT DEC 26 2015

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

A VERY SERIOUS AND POTENTIALLY HISTORIC HEAVY RAINFALL AND
FLOODING EVENT IS LIKELY THIS AFTERNOON THROUGH MONDAY. A FLASH
FLOOD WATCH IS IN EFFECT FOR MOST OF THE REGION.

HEAVY RAIN AND THUNDERSTORMS ARE EXPECTED TO DEVELOP THIS
AFTERNOON AND CONTINUE TONIGHT. A FEW OF THE STORMS COULD BE
SEVERE ALONG AND SOUTH OF INTERSTATE 70. HEAVY RAIN WILL CAUSE
RAPID RISES ALONG CREEKS, STREAMS AND RIVERS. FLASH FLOODING OF
LOW LYING AREAS IS LIKELY.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

A VERY SERIOUS AND POTENTIALLY HISTORIC HEAVY RAINFALL AND
FLOODING EVENT IS LIKELY THIS AFTERNOON THROUGH MONDAY. A FLASH
FLOOD WATCH IS IN EFFECT FOR MOST OF THE REGION.

ANOTHER PERIOD OF POTENTIALLY HEAVY RAINFALL WILL OCCUR SUNDAY
THROUGH MONDAY. STORM TOTAL RAINFALL AMOUNTS OF 5 TO 8 INCHES ARE
LIKELY ALONG AND SOUTH OF JEFFERSON CITY MISSOURI TO CARLINVILLE
ILLINOIS LINE, WITH AMOUNTS OF 3 TO 5 INCHES NORTH OF THIS LINE.

THIS HEAVY RAINFALL WILL LIKELY RESULT IN LIFE-THREATENING FLASH
FLOODING OF LOW LYING OR POOR DRAINAGE AREAS...AND SMALLER CREEKS
AND STREAMS. FLOODING OF MOST RIVERS IS EXPECTED WITH MAJOR AND
POSSIBLY HISTORIC FLOODING ON SOME RIVERS ACROSS THE SOUTHEAST
HALF OF MISSOURI AND SOUTHWEST ILLINOIS.

.SPOTTER INFORMATION STATEMENT...

SPOTTERS ARE ASKED TO RELAY RAINFALL AMOUNTS EXCEEDING 2 INCHES,
FLOODING AND SEVERE WEATHER REPORTS TO THE NATIONAL WEATHER
SERVICE IN ST. LOUIS.

CVKING