000 FXUS63 KEAX 261003 CCA AFDMCI AREA FORECAST DISCUSSION...CORRECTED FOR WWA INFO NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO 250 AM CST MON JAN 26 2004 .DISCUSSION... EARLY MORNING SATELLITE IMAGERY AND OBJECTIVE UPPER AIR ANALYSIS INDICATE LONGWAVE TROUGH EXTENDING ACROSS ROCKIES AND CENTRAL PLAINS...WITH TWO EMBEDDED SHORTWAVE FEATURES OF INTEREST TO FORECAST AREA. WEAK SHORTWAVE TROUGH CURRENTLY LIFTING NORTHEAST ACROSS SOUTHEAST KANSAS...WHILE UPSTREAM STRONGER SHORTWAVE IS NOTED OVER SOUTHERN ROCKIES. 850MB ANALYSIS DEPICTS BAROCLINIC ZONE EXTENDING FROM NORTHERN OK INTO WEST CENTRAL MISSOURI...ASSOCIATED WITH LOW OVER SOUTHEAST KANSAS. REGIONAL 88-D RADAR IMAGERY INDICATES LIGHT SNOW ACROSS NORTHWEST MO...RESULTING FROM LEADING EDGE OF VORTICITY ADVECTION ASSOCIATED WITH SOUTHEASTERN KANSAS SHORTWAVE. AS THIS SHORTWAVE CONTINUES TO LIFT ACROSS CENTRAL/NORTHERN MISSOURI 850MB LOW IS PROGGED TO TRACK FROM NEAR AN MKC TO IRK LINE THIS MORNING. LIFT ASSOCIATED WITH FRONTOGENETIC FORCING AHEAD OF THIS LOW...COMBINED WITH WEAK LARGE SCALE ASCENT ASSOCIATED WITH PASSING SHORTWAVE...SHOULD ALLOW AREAS OF SNOW TO SPREAD ACROSS WEST CENTRAL MO THROUGH MID MORNING...THEN INTO NORTH CENTRAL MO BY LATE MORNING. SOME OF THIS PRECIPITATION MAY BEGIN AS LIGHT FREEZING DRIZZLE AT THE ONSET AROUND THE KANSAS CITY AREA WHERE DENDRITIC LAYER REMAINS UNSATURATED...HOWEVER AS LOW LEVELS (AROUND 925MB) CONTINUE TO COOL BELOW -10C...PRECIP SHOULD QUICKLY TURN OVER TO LIGHT SNOW. NOT EXPECTING MORE THAN A DUSTING TO AN INCH ACROSS MOST OF WEST CENTRAL INTO NORTH CENTRAL MO...WHILE AN ADDITIONAL INCH OR TWO WILL BE POSSIBLE ACROSS FAR NORTHWESTERN MO. EXPECT A LULL IN PRECIPITATION THIS AFTERNOON BEHIND INITIAL SHORTWAVE...AS SOUTHERN ROCKIES SHORTWAVE CONTINUES TO DIG/AMPLIFY ACROSS SOUTHERN PLAINS. AS THIS WAVE BEGINS TO LIFT INTO OZARKS REGION LATE THIS AFTERNOON/EVENING...EXPECT SNOW TO SPREAD ACROSS EXTREME EAST CENTRAL KS INTO WEST CENTRAL MO AS LIFT ASSOCIATED WITH 850-500MB Q-VECTOR CONVERGENCE SPREADS ACROSS AREA. THIS PRECIPITATION SHOULD THEN SPREAD ACROSS REMAINDER OF CENTRAL MO THIS EVENING. AM SOMEWHAT CONCERNED THAT SNOW RATIOS MAY BE CLOSER TO 15-1 OR 20-1 AS MUCH COLDER AIR FILTERS INTO THE AREA...WHICH WOULD YIELD UP TO 3-4 INCHES OF SNOW ACROSS FAR SOUTHERN COUNTIES...WITH AN INCH OR SO FURTHER NORTH ALONG A KANSAS CITY TO KIRKSVILLE LINE. HOWEVER TIGHTENING GRADIENT ASSOCIATED WITH SURFACE LOW OVER MID MS RIVER VALLEY WILL RESULT IN CONSIDERABLE BLOWING OF SNOW...MAKING ANY ACCURATE SNOW MEASUREMENTS DIFFICULT. WILL GO AHEAD AND ISSUE WINTER WEATHER ADVISORY FOR FAR SOUTHERN COUNTIES FOR LATE THIS AFTERNOON THROUGH THIS EVENING. EXPECT PRECIPITATION TO EXIT CWA LATE TONIGHT AS LARGE SCALE FORCING SHIFTS EAST OF AREA. AS FAR AS TEMPERATURES GO...EXPECT TEMPS TO REMAIN FAIRLY STEADY STATE TODAY IN THE LOW/MID 20S...HOWEVER AS COLDER AIRMASS WORKS INTO AREA TONIGHT...EXPECT MIN TEMPS TO BOTTOM OUT IN THE SINGLE DIGITS ACROSS NORTHWESTERN ZONES...WITH MID TEENS ACROSS EAST WHERE PRECIPITATION WILL BE ENDING. SURFACE RIDGE TO BUILD INTO REGION TUESDAY...AND WITH -12C 925 MB COLD POOL ACROSS AREA...WILL BE LUCKY TO SEE MAX TEMPS MAKE IT OUT OF THE TEENS. RETURN FLOW PROGGED TO SET UP LATE TUESDAY NIGHT ALLOWING TEMPS TO REBOUND TO NEAR/SLIGHTLY ABOVE NORMAL FOR THE LATTER HALF OF THE WEEK. SEAMAN && .PREV DISCUSSION... 940 PM SUN JAN 25... UPDATING FORECAST THROUGH MONDAY EVENING. NOT MUCH EXPECTED TO HAPPEN OVER THE EASTERN 2/3 OF FORECAST AREA THROUGH 09Z. BAND OF LIGHT SNOW HOLDING ITS OWN ACROSS FAR NORTHWEST MO AND SNOW SHOULD CONTINUE/SPREAD A BIT EASTWARD OVERNIGHT. ANOTHER INCH..POSSIBLY TWO FOR THE NORTHWEST TIP OF MO. FURTHER SOUTH WILL AWAIT ARRIVAL OF VORTICITY CENTER NOW OVER NORTH CENTRAL OK. THIS FEATURE WILL TRACK NORTHEAST OVERNIGHT. ENHANCED LIFT SHOULD RESULT IN DEVELOPMENT OF AN AREA OF LIGHT FREEZING DRIZZLE AND/OR LIGHT SNOW..SPREADING INTO EAST CENTRAL KS/WEST CENTRAL MO BY 12Z MON. SOUNDING PROFILES COULD SUPPORT EITHER ONE TILL SATURATED COLD LAYER...NEAR THE BOUNDARY LAYER...COOLS OFF A FEW DEGREES. THIS SHOULD OCCUR AROUND 12Z. BETTER ACCUMULATING SNOW LOOKS LIKE IT SHOULD BE CONFINED TO FAR SOUTHERN COUNTIES TOMORROW...STARTING IN THE SOUTHWEST CORNER IN THE MORNING AND SPREAD INTO CENTRAL MO DURING THE AFTERNOON AND EARLY EVENING. COUPLE INCHES OF SNOW LIKELY. DEPENDING UPON HOW PRECIPITATION DEVELOPS AND SNOW INTENSITY LOOKS UPSTREAM...MAY NEED TO ISSUE A WINTER WEATHER ADVISORY FOR MONDAY AFTERNOON/EARLY EVENING FOR FAR SOUTHERN COUNTIES. MJ && .PREV DISCUSSION... 425 PM... INITIAL UPPER SHORTWAVE HAS LIFTED NORTHEAST TOWARD EASTERN MISSOURI/WESTERN ILLINOIS WHICH HAS ALLOWED THE PRECIPITATION SHIELD TO DIMINISH TO A FEW AREAS OF FLURRIES ACROSS NORTH CENTRAL AND CENTRAL MISSOURI. A WEAKER UPPER LEVEL FEATURE OVER KANSAS AND NEBRASKA HAS KEPT SUFFICIENT LIFT OVER THE FAR NORTHWEST CORNER OF MISSOURI AND ALONG THE NORTHERN KANSAS AND MISSOURI BORDER FOR A WINTRY MIX OF PRECIPITATION...INCLUDING FREEZING RAIN...SLEET AND SNOW TO CONTINUE. AM EXPECTING THIS AREA OF PRECIPITATION TO DIMINISH TO MAINLY FLURRIES BY LATE EVENING BEFORE OUR NEXT WAVE PROGRESSES SOUTHEAST OUT OF SOUTHERN WYOMING. SNOW IS EXPECTED TO DEVELOP BY 12Z MONDAY ACROSS EASTERN KANSAS AND NORTHWEST MISSOURI AS MIDLEVEL FRONTOGENETIC FORCING GETS GOING IN ACCORDANCE WITH THE 850MB BAROCLINIC ZONE. WHILE THIS AREA OF SNOW WILL TAPER OFF DURING THE AFTERNOON...ANOTHER AREA OF SNOW WILL DEVELOP ACROSS SOUTHEAST KANSAS AND WEST CENTRAL MISSOURI IN ASSOCIATION WITH THE MAIN UPPER VORTICITY LOBE TO MOVE TOWARD SOUTHWEST MISSOURI. THE HIGHEST SNOWFALL ACCUMULATIONS LOOK TO BE AROUND 3 INCHES ACROSS NORTHERN MISSOURI AND ACROSS WEST CENTRAL TO CENTRAL MISSOURI...WITH 1 TO 2 INCHES IN BETWEEN. THE AVN IS THE PREFERRED MODEL WITH TOMORROWS UPPER TROUGH IN TERMS OF TIMING. THE ETA SEEMS TOO FAST WITH THIS TROUGH AND SO WILL FOLLOW THE AVN AS IT HAS HAD A BETTER HANDLE ON THE ONGOING UPPER LEVEL FEATURES. THERE IS CONCERN THAT THE TROUGH OF WARM AIR ALOFT SHOWN BY THE AVN TO SET UP ACROSS CENTRAL AND SOUTHERN MISSOURI COULD PRODUCE ENHANCED SNOW BANDS. ANY SNOW THAT DOES FALL TOMORROW WILL BLOW AROUND WITH STRONG NORTH WINDS. THE SNOW IS EXPECTED TO COME TO AN END BEFORE 12Z TUESDAY AS THE UPPER TROUGH AXIS MOVES EAST OF THE AREA. IN THE EXTENDED...MODELS HAVE HAD DIFFICULTLY WITH CONSISTENT TIMING OF SHORTWAVES IN FAST ZONAL ACROSS THE NORTHERN AND CENTRAL US. THE ZONAL FLOW WILL ESSENTIALLY KEEP ANY SIGNIFICANT COLD CANADIAN AIR OUT OF THE CENTRAL PLAINS. THEREFORE HAVE MODIFIED TEMPERATURES FROM THE PREVIOUS PACKAGES. SEVERAL FAST MOVING SHORTWAVES MOVE THROUGH THE FLOW THROUGH THE PERIOD WITH THE FIRST LATE WEDNESDAY AND THURSDAY. LACK CONFIDENCE ON TIMING WITH SHORTWAVE ALSO LACKING MOISTURE. WILL KEEP POPS VERY LOW AT THIS TIME. SYSTEM ON SATURDAY LOOKS WEAK AT THIS TIME...ALTHOUGH THE ECMWF AND UKMET SUGGEST THE SYSTEM COULD BE STRONGER. THE UKMET SUGGESTS IT MAY WAIT TILL LATE IN THE WEEKEND. THEREFORE...WILL HOLD OFF MENTION OF PRECIPITATION AT THIS TIME. STOFLET/DB && .EAX WATCHES/WARNINGS/ADVISORIES... KS...WINTER WEATHER ADVISORY FOR LINN COUNTY FROM 3 PM THIS AFTERNOON UNTIL MIDNIGHT. SEE STLWSWMCI FOR DETAILS. MO...WINTER WEATHER ADVISORY FOR FAR SOUTHWESTERN COUNTIES FROM 3PM THIS AFTERNOON UNTIL MIDNIGHT. SEE STLWSWMCI FOR DETAILS. WINTER WEATHER ADVISORY FOR FAR SOUTHEASTERN COUNTIES FROM 6 PM TONGHT UNTIL 3 AM TEUSDAY MORNING. SEE STLWSWMCI FOR DETAILS. $$ WFO EAX