River Flood Warning 3, NWS Kansas City, MO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO
536 AM CST TUE JAN 19 2010

...UPDATED AVIATION DISCUSSION...

.DISCUSSION...

IN THE SHORT TERM...YET ANOTHER NIGHT OF EXPANSIVE STRATUS AND DENSE
FOG ACROSS THE CWA.  VISIBILITIES HAVE CONTINUED TO BE MUCH MORE
VARIABLE THIS MORNING...DUE IN PART TO SLIGHTLY BETTER MIXING WITH
AN EAST WIND BETWEEN 5-10 MPH.  DESPITE THE INTRODUCTION OF COLDER
SFC HIGH PRESSURE OVER THE GREAT LAKES...BOUNDARY LAYER CAA HAS BEEN
LIMITED SIGNIFICANTLY.  CURRENTLY ONLY AREAS BELOW FREEZING ARE ALONG
THE IMMEDIATE IOWA BORDER REGION.  FURTHER SOUTH...A WELL DEFINED
SFC WARM FRONT FALLS ALONG THE OZARKS WITH UPR 40S PINNED IN
SOUTHERN MO.

THE SHORT TERM FCST TURNS MORE INTERESTING AS WE HEAD INTO AND
THROUGH THE MIDDLE PORTIONS OF THE WORK WEEK.  NOSE OF AN INCREDIBLY
INTENSE UPR JET IS NOW BEGINNING TO PUSH ONTO THE CALIFORNIA
COAST...DRIVING SEVERAL PAC S/W TROUGHS TOWARDS THE CONUS. THE FIRST
SUCH WAVE IS NOW CROSSING THE SOUTHERN ROCKIES THIS MORNING PRODUCING
LIGHTNING ACTIVITY AS IT CROSSED CALIFORNIA. THIS WAVE IS EXPECTED TO
REACH THE CWA LATER THIS EVENING. IN THE MEANTIME...EXTENSIVE STRATUS
AND FOG WILL CONTINUE THROUGHOUT THE DAYTIME HOURS. UNLIKE THE PAST
FEW DAYS...AN INCREASING SFC PRESSURE GRADIENT FROM SFC CYCLOGENESIS
TO OUR SW AND SFC RIDGING TO THE NE WILL PRODUCE A SLIGHTLY STRONGER
EASTERLY COMPONENT AS THE WARM FRONT REMAINS SOUTH OF THE CWA TODAY.
THIS INCREASED MIXING SHOULD ALLOW VIS TO INCREASE STEADILY THIS
MORNING. WILL NOT MODIFY THE DENSE FOG ADVISORY...BUT IT MAY NEED TO
BE CANCELLED EARLY. BY THE AFTN HOURS...WEAK ISENTROPIC LIFT WILL
COMMENCE IN THE LOWER LVLS OF THE ATMOSPHERE AS THE SFC WARM FRONT
BEGINS TO LIFT NORTHWARD. SOUNDINGS SUGGEST AREAS OF DRIZZLE OR PERHAPS
EVEN A LIGHT RAIN SHOWER MAY DEVELOP AFTER NOON. TEMPS WILL REMAIN
TRICKY TODAY...GIVEN THE EXTENSIVE STRATUS ALOFT AND REINFORCING WEAK
CAA FROM THE NE...AREAS OF NORTHERN MO MAY STRUGGLE TO CLIMB MUCH PAST
THE FREEZING MARK.

BY THIS EVE...FAIRLY INTENSE AND DEEP ISENTROPIC LIFT WILL COMMENCE
AHEAD OF THE APPROACHING S/W. EXPECTING AN ELONGATED AREA OF
DRIZZLE/SHOWERS BY THE EVENING HOURS LIFTING FROM SW TO NE. SOUNDINGS
INDICATE AT LEAST SOME WEAK ELEVATED INSTABILITY WITH DECENT SIGNALS
FROM SEVERAL ELEVATED CONVECTION PARAMETERS TO SUPPORT A CONTINUED ISO
THUNDER MENTION IN THE GRIDS.

OF MORE QUESTION WILL BE THE SFC THERMAL PROFILE IN THE NORTHERN
PORTIONS OF THE CWA OVERNIGHT.  GENERALLY FOLLOWING THE GFS/ECMWF
WHICH HAS INITIALIZED VERY WELL WITH CURRENT READINGS.  THE NAM HAS
BEEN TOO COLD AT THE SFC AND HAS TOO MUCH CAA IN THE BOUNDARY
LAYER.  WHILE READINGS MAY ONLY CLIMB JUST ABOVE FREEZING IN THE
NOR THEN CWA THIS AFTN...GFS/EC/GEM AND EVEN LATEST NAM SUGGEST A
MUCH DEEPER AND FURTHER NORTH TRACK OF SFC LOW PRESSURE AS THE S/W
CROSSES THE AREA OVERNIGHT TONIGHT. THE PROGRESSIVE NATURE OF THE UPR
TROUGH SHOULD ALLOW A FAIRLY WARM SURGE OF AIR TO BE PULLED
NORTHWARD INTO THE CWA. HAVE LEVELED OFF TEMPS AND EVEN INDICATED
RISING TEMPS SOUTH OF I-70 THROUGH DAYBREAK WED.

FEEL THE ONLY CHC OF ANY LIGHT ICING WILL BE ALONG THE EXTREME
NORTHERN PORTION OF MISSOURI AND THAT CHANCE MAY BE SLIGHT.  A
COUPLE FACTORS WEIGH IN...FIRST AND FOREMOST BEING INCREASING
BOUNDARY LAYER WAA FROM APPROACHING SFC LOW.  SECONDLY...GIVEN THE
WARM PROFILES ALOFT...ANY LIGHT TO MODERATE RAINFALL WILL CERTAINLY
TRY TO MIX DOWN WARMER AIR TO THE SFC. NEVERTHELESS...A LIGHT ICING
UNDER ONE TENTH OF AN INCH MAY BE POSSIBLE ON ELEVATED SFCS NEAR THE
IA BOARDER THROUGH WEDNESDAY MORNING. NO PLANS TO ISSUE ANY WINTER WX
PRODUCT ATTM...AND WILL ALLOW THE NEXT FCSTER TO REEVALUATE THROUGH
THE DAY AS TEMPS AND TRENDS CAN BE VISUALIZED.

A BRIEF BREAK MAY ARRIVE FOR MUCH OF THE DAYTIME HOURS OF WEDNESDAY
AS THE S/W RAPIDLY LIFTS NE AND SYNOPTIC SUBSIDENCE SETS IN.  HAVE
LOWERED POPS SOME WHICH MAY NEED TO BE LOWERED FURTHER (MORE LIKELY
IN THE AFTN). STRATUS DOES LOOK TO REMAIN IN PLACE...BUT DUE TO
SUBSIDENCE ABOVE THE LAYER MAY NOT BE DEEP ENOUGH TO PRODUCE DRIZZLE.
TEMPS ON WEDNESDAY SHOULD CLIMB INTO THE LOWER 50S SOUTH OF HWY 50
BEFORE LEVELING OFF OR DROPPING IN THE AFTN.

NEXT S/W QUICKLY RACES IN BEHIND THE INITIAL WAVE FOR WED NIGHT AND
THU.  EC REMAINS A STRONG AND NORTHERN OUTLIER ATTM...WITH ALL OTHER
GUIDANCE FURTHER SOUTH AND LESS INTENSE.  NEVERTHELESS WILL LOWER
POPS IN THE NORTHERN ZONES AND INCREASE POPS IN THE SOUTHERN
ZONES. THE POTENTIAL FOR A QUICK QUARTER INCH OF QPF COULD NEARLY
ASSURE MINOR RIVER FLOODING IN THE SOUTHERN CWA.

UPR STORM STILL ON TRACK FOR THE END OF THE WEEK WITH A NICE WARMUP
FOR FRI AND SAT.  WILL NOT GO AS HIGH AS SOME GUIDANCE SUGGESTS FOR
FRIDAY (MID-UPR 50S) ALTHOUGH POTENTIAL DOES EXIST. MY MAIN POINT OF
CONTENTION IS A PURELY SE COMPONENT TO THE BOUNDARY LAYER WINDS.
TYPICALLY NOT A GOOD WARMING WIND FOR THE CWA ESPECIALLY WITH VERY
MOIST GROUND COVER REMAINING. STILL...MID TO UPR 40S SEEMS VERY
PLAUSIBLE.

DUX

&&

.AVIATION...

FOR THE 12Z TAFS...THE VSBYS HAVE GRADUALLY IMPROVED DURING THE LAST
FEW HOURS AS SFC WINDS HAVE SLOWLY INCREASED. THE INCREASE IN WINDS
WAS DUE TO THE APPROACH OF A WEAK UPPER LEVEL STORM SYSTEM. ALTHOUGH
VSBYS MAY TEMPORARILY BE REDUCED TO BELOW ONE MILE AT TIMES THROUGH
14Z...VSBYS WILL SEE A SLOW IMPROVEMENT THIS MORNING AS SFC WINDS
CONTINUE TO INCREASE. CIGS WILL REMAIN LOW THIS MORNING...BUT WILL
ALSO SEE A SLOW INCREASE IN HEIGHT THROUGH THE DAY DUE TO DAYTIME INSOLATION.
REGARDLESS CIGS WILL REMAIN BELOW 1000 FEET. RAIN IS EXPECTED TO MOVE
INTO THE TERMINALS THIS EVENING AS THE UPPER LEVEL STORM SYSTEM MOVES
INTO MISSOURI. CIGS WILL REMAIN IN THE IFR CATEGORY AS THE TERMINALS
WILL LIKELY REMAIN NORTH OF A WARM FRONT WHICH WILL MOVE NORTH FROM
SRN MO TONIGHT. OTHERWISE...WINDS WILL INSURE GOOD LOW LEVEL MIXING
TONIGHT...LIKELY KEEPING VSBYS IN THE MVFR CATEGORY.

DB

&&

.EAX WATCHES/WARNINGS/ADVISORIES...
MO...DENSE FOG ADVISORY UNTIL NOON CST TODAY FOR MOZ001>008-011>017-
     020>025-028>033-037>040-043>046-053-054.

KS...DENSE FOG ADVISORY UNTIL NOON CST TODAY FOR KSZ025-057-060-
     102>105.

&&

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO
553 AM CST TUE JAN 19 2010

KSZ025-057-060-102>105-MOZ001>008-011>017-020>025-028>033-037>040-
043>046-053-054-201200-
ATCHISON KS-MIAMI-LINN KS-DONIPHAN-LEAVENWORTH-WYANDOTTE-
JOHNSON KS-ATCHISON MO-NODAWAY-WORTH-GENTRY-HARRISON-MERCER-
PUTNAM-SCHUYLER-HOLT-ANDREW-DE KALB-DAVIESS-GRUNDY-SULLIVAN-ADAIR-
BUCHANAN-CLINTON-CALDWELL-LIVINGSTON-LINN MO-MACON-PLATTE-CLAY-
RAY-CARROLL-CHARITON-RANDOLPH-JACKSON-LAFAYETTE-SALINE-HOWARD-
CASS-JOHNSON MO-PETTIS-COOPER-BATES-HENRY-
553 AM CST TUE JAN 19 2010

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHWEST...NORTH CENTRAL
AND WEST CENTRAL MISSOURI...AS WELL AS EXTREME EASTERN KANSAS.

.DAY ONE...TODAY AND TONIGHT

AREAS OF FOG WILL CONTINUE THROUGH THE MORNING HOURS. VISIBILITIES
WILL GENERALLY REMAIN NEAR ONE HALF MILE IN MOST LOCATIONS...HOWEVER
LOCALIZED VISIBILITIES OF ONE QUARTER MILE OR LESS WILL REMAIN
POSSIBLE THROUGH MID-MORNING. VISIBILITIES MAY RAPIDLY IMPROVE
THROUGH THE MORNING.

AN UPPER LEVEL STORM SYSTEM WILL CROSS THE REGION TUESDAY NIGHT INTO
WEDNESDAY MORNING. SHOWERS WILL BEGIN TO OVERSPREAD THE OUTLOOK AREA
THIS EVENING AND LIFT NORTHWARD THROUGH THE NIGHT. WHILE MUCH OF THE
PRECIP WILL REMAIN IN THE FORM OF RAIN...TEMPERATURES IN EXTREME
NORTHERN MISSOURI MAY HOLD NEAR THE FREEZING MARK INTO WEDNESDAY
MORNING. THIS MAY LEAD TO THE POTENTIAL FOR LIGHT ICING DURING THE
OVERNIGHT HOURS...WITH ICE ACCUMULATIONS GENERALLY UNDER ONE TENTH OF
AN INCH AND MAINLY OCCURRING ON ELEVATED SURFACES.

ADDITIONALLY...AN ISOLATED CLAP OF THUNDER MAY ALSO BE POSSIBLE
ACROSS PORTIONS OF CENTRAL MISSOURI TONIGHT. SEVERE WEATHER IS NOT EXPECTED.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

RAIN WILL EXIT THE AREA WEDNESDAY MORNING...BEFORE AN ADDITIONAL
CHANCE FOR RAIN MOVES INTO THE AREA FROM THE SOUTHWEST WEDNESDAY
NIGHT AND THURSDAY. ADDITIONAL RAINFALL OVER MOSTLY FROZEN GROUNDS
MAY LEAD TO RIVER FLOODING...ESPECIALLY IN AREAS SOUTH OF THE
INTERSTATE 70 CORRIDOR.

AN ADDITIONAL CHANCE FOR RAIN MAY ARRIVE FRIDAY NIGHT AND
SATURDAY...WITH THE THREAT FOR RIVER FLOODING INCREASING AT THAT
TIME.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED. HOWEVER SPOTTERS IN AREAS
NEAR THE IOWA BORDER ARE ENCOURAGED TO REPORT ANY ICE ACCUMULATIONS WHICH
MAY OCCUR TUESDAY NIGHT AND WEDNESDAY MORNING.

DUX