FXUS63 KEAX 042230 CCA
AFDMCI

AREA FORECAST DISCUSSION...CORRECTION
NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO 
415 PM CST THU MAR 4 2004

CORRECTION TO WATCH/WARNING LAT/LON POINTS

.DISCUSSION...

STRONG MID/UPPER LEVEL WAVE EVIDENT ON AFTERNOON SATELLITE IMAGERY. 
RESULTANT STRONG FRONTOGENETICAL FORCING AND LOW LEVEL SOUTHERLY 
WINDS HAVE CONTINUED TO LIFT MOISTURE OVER THE BAROCLINIC ZONE 
TODAY...RESULTING IN SIGNIFICANT RAINFALL ACROSS THE FORECAST AREA. 
COUPLED JET STRUCTURE HAS ALSO OFFERED ADDITIONAL SUPPORT. AS THE 
BOUNDARY CONTINUES TO LIFT NORTH...THE IMMEDIATE THREAT WILL CHANGE 
TO THE POTENTIAL FOR SEVERE WEATHER THIS EVENING. DRY SLOT CONTINUES 
TO WORK NORTH INTO SOUTHEAST KANSAS AND SOUTHWEST 
MISSOURI...ALLOWING FOR SOME DESTABILIZATION. SOME UNCERTAINTY ON 
HOW FAR NORTH THE DRY SLOT WILL WORK. CURRENT THOUGHTS ARE THAT 
SOUTHERN TIER OF ZONES MAY SEE SUFFICIENT CLEARING. THIS INSTABILITY 
IS EXPECTED TO COMBINE MODERATE SHEAR IN VICINITY OF THE DEEPENING 
SURFACE LOW...AND CONTRIBUTE TO A THREAT FOR TORNADOES IN THE 
EXTREME SOUTHERN PORTION OF THE CWA. LARGE HAIL IS NOT A BIG 
CONCERN...DUE TO FAIRLY WARM 500MB TEMPS. EXPECT TEMPS TO RISE 
THROUGH THE EVENING AS THE WARM SECTOR LIFTS NORTH. 

SCHMIT

FAST MOVING IMPULSE IN NORTHWESTERLY FLOW WILL TRACK ACROSS THE 
UPPER MISSISSIPPI VALLEY SATURDAY AFTERNOON AND EVENING. MOST OF THE 
PRECIPITATION SHOULD STAY NORTH OF THE AREA. SPRINKLES POSSIBLE 
FURTHER SOUTH ALONG COLD FRONT OVER PARTS OF NORTHERN MO BUT NOT 
READY TO INTRODUCE CHANCE FOR MEASURABLE RAIN. ANOTHER FAST MOVING 
IMPULSE WILL MOVE THROUGH MONDAY/MONDAY NIGHT WITH WINDSHIFT THE 
MAIN EFFECT. UPCOMING WORK WEEK LOOKS DRY AND WILL HELP REGION DRY 
OUT FROM TODAYS HEAVY RAINS.

BY MID WEEK UPPER RIDGE PROGGED TO BUILD EAST FROM THE ROCKIES... 
RESULTING IN GOOD LOW LEVEL WARM ADVECTION. HAVE BUMPED UP 
TEMPERATURES AND EVEN THEN MAY BE TOO CONSERVATIVE IF WARMING IS AS 
STRONG AS GFS IS ADVERTISING. 

MJ

&&

.PREVIOUS DISCUSSION...

750 AM...
MORE ADJUSTMENTS WERE MADE TO THE FORECAST FOR THIS MORNING.  THE 
RAPID EXPANSION OF PRECIP TO THE NORTH...UNDER THE INFLUENCE OF A 
STRONG LOW LEVEL JET...HAS NECESSITATED EXPANDING OUR CATEGORICAL 
RAIN POPS FARTHER NORTH FASTER. THE PROFILER NETWORK INDICATES THAT 
THE JET FULLING THE CURRENT ROUND OF STORMS IS BEGINNING TO VEER. AS 
THIS OCCURS THE UPPER LEVEL BOUNDARY...THAT THESE STORMS ARE 
FOCUSING ON WILL...STALL ACROSS THE NORTHERN HALF OF MISSOURI 
ALLOWING THEM TO TRAIN ACROSS THE REGION. 

CUTTER

633 AM...
MADE A QUICK ADJUSTMENT TO THE ZONES THIS MORNING TO REMOVE THE 
DENSE FOG ADVISORY. CONVECTION HAS JUMPED RAPIDLY NORTH INTO THE 
SOUTHERN HALF OF THE COUNTY WARNING AREA THIS MORNING WITH THE HELP 
OF BACKING WINDS IN ADVANCE OF THE LOW IN NORTHERN MEXICO. MIXING... 
ASSOCIATED WITH THE RAIN...HAS ALLOWED VISIBILITIES TO COME UP JUST 
ENOUGH TO ALLOW US TO CANCEL THE DENSE ADVISORY EARLY. HOWEVER... 
PATCHY FOG IS STILL EXPECTED TO BE PREVALENT THROUGH THE MID MORNING 
HOURS.

CUTTER

432 AM...
THE MAIN FOCUS OF THIS MORNING FORECAST CENTERS AROUND THE POTENTIAL 
FOR CONVECTION AND FLOODING TODAY AND TONIGHT. 

A BROAD SOUTHWEST FLOW DOMINATES THE LOWER HALF OF THE MISSISSIPPI 
RIVER VALLEY THIS MORNING AS A DEEPENING CUT-OFF LOW DIGS ITS WAY 
THROUGH THE GULF OF CALIFORNIA INTO NORTHERN MEXICO. AN UPPER LEVEL 
FRONTAL BOUNDARY...LANGUISHING OVER THE OZARKS...HAS BEEN THE FOCUS 
FOR CONVECTION OVERNIGHT. A PARALLEL WIND FLOW ALONG THE BOUNDARY 
HAS KEPT THE ACTIVITY CONFINED TO SOUTHERN MISSOURI THUS FAR. 
HOWEVER...PROFILER AND SATELLITE DATA INDICATE THAT WINDS ARE 
BEGINNING TO BACK AHEAD OF THE LOW MOVING INTO NORTHERN MEXICO. THIS 
HAS SPAWNED THUNDERSTORM ACTIVITY FROM NORTH CENTRAL OKLAHOMA INTO 
SOUTHEAST KANSAS AND SOUTHWEST MISSOURI. 

OVERNIGHT THE MOISTURE LEFT BEHIND BY WEDNESDAYS RAIN WAS ENOUGH TO 
ALLOW DENSE FOG TO SPROUT ACROSS THE REGION. WENT AHEAD AND ISSUED A 
DENSE FOG ADVISORY FOR THE ENTIRE COUNTY WARNING AREA TILL NOON. I 
FIGURE AS THE CONVECTION WORKS ITS WAY IN THIS MORNING THE ADVISORY 
CAN BE CLEARED FROM SOUTH TO NORTH AS VISIBILITIES COME UP A LITTLE 
UNDER THE INFLUENCE OF THE RAIN. 

WITH THE ACTIVITY DEVELOPING TO THE SOUTH...THUNDERSTORMS WILL BE 
ONGOING ACROSS THE SOUTHERN EDGE OF THE FORECAST AREA AT SUNRISE. 
LATEST RUNS OF THE GFS AND ETA MODELS INDICATE THAT THE LOW WILL 
LIFT A LITTLE FARTHER NORTH TONIGHT...PASSING OVER THE EXTREME 
NORTHEAST CORNER OF KANSAS AND NORTHWEST CORNER OF MISSOURI. A 
STRONG LOW LEVEL JET...CROSSING THE WARM FRONT...WILL PUSH IT NORTH 
TODAY AHEAD OF A DRY LINE SWEEPING THROUGH TEXAS AND OKLAHOMA. WITH 
VAST AMOUNTS OF MOISTURE AND LIFT ALONG THE 290-295K SURFACES HEAVY 
RAIN AND EMBEDDED THUNDERSTORM ACTIVITY WILL MOVE NORTH THROUGH 
CENTRAL AND NORTHERN MISSOURI...AND THE EASTERN EDGE OF KANSAS THIS 
AFTERNOON AND EVENING. INDICATIONS ARE THAT A DRY SLOT WILL WORK ITS 
WAY IN UNDER THE LOW AS IT LIFTS NORTHEAST TONIGHT. THUS...I HAVE 
ADJUSTED FRIDAYS FORECAST TO CLEAR OUR RAIN AND THUNDERSTORMS FROM 
THE SOUTHWEST DURING THE MORNING HOURS. AS FOR OUR FLOOD WATCH...I 
HAVE  EXPANDED IT TO INCLUDE THE ENTIRE COUNTY WARNING AREA...AND 
WILL RUN IT FROM 3 PM THIS AFTERNOON THROUGH 6 AM FRIDAY MORNING. 

THERE WILL BE A MARGINAL THREAT OF SEVERE THUNDERSTORMS LATER THIS 
AFTERNOON AND THIS EVENING AS THE WARM SECTOR LIFTS THROUGH THE 
REGION. WITH HILICITIES RUNNING FROM 300-500 M2/S2...AND SHEAR 
VALUES AROUND 50 KTS...THERE IS THE POTENTIAL FOR SUPERCELL 
ACTIVITY. HOWEVER...THESE FAVORABLE SHEAR VALUES ARE ACCOMPANIED BY 
LAPSE RATES IN THE 5-5.5 DEGREE C/KM RANGE...PRECIPITABLE WATER 
VALUES IN THE 1.5 INCH RANGE...AND A MOIST ADIABATIC SOUNDING. THIS 
MITIGATES OUR POTENTIAL SIGNIFICANTLY AS THE INSTABILITY NECESSARY 
TO SUPPORT ACTIVE SEVERE WEATHER DOES NOT LOOK TO BE THERE. ONLY AS 
THE DRY SLOT WORKS ITS WAY THROUGH KANSAS INTO MISSOURI OVERNIGHT 
DOES COOLING ALOFT ALLOW FOR ENOUGH INSTABILITY TO SUPPORT SEVERE 
STORMS. BY THAT TIME SHEAR PROFILES WILL HAVE ADJUSTED TO SUPPORT 
MORE OF A LINEAR TYPE STORM EVENT...AND THATS ONLY IF IT CAN TAP 
SUFFICIENT SURFACE MOISTURE FROM WITHIN THE DRY SLOT. SO...THE MAIN 
THREAT WITH ANY SEVERE THUNDERSTORM ACTIVITY SHOULD BE LIMITED TO 
HAIL AND STRONG STRAIGHT LINE WINDS.  

CUTTER

915 PM WED...
UPPER LOW CURRENTLY LOCATED OVER GULF OF CA WITH BROAD SOUTHWESTERLY 
FLOW ALOFT ACROSS CENTRAL CONUS. WEAK SHORTWAVE NOTED LIFTING INTO 
MID MS RIVER VALLEY...WHICH HELPED TO TRIGGER MCS ACROSS EASTERN OK 
INTO SOUTHERN MO THIS AFTERNOON. LOW LEVEL FLOW HAS VEERED BEHIND 
THIS FEATURE...HOWEVER WEAK CONVECTION CONTINUES ALONG FRONTAL 
BOUNDARY DRAPED ACROSS SOUTHERN MO THIS EVENING. LATEST MODEL RUNS 
SUGGEST LOW LEVEL FLOW TO BACK LATE TONIGHT IN RESPONSE TO 
APPROACHING GULF OF CA LOW AS IT BEGINS TO ACCELERATE EASTWARD. 
RESULTANT ISENTROPIC LIFT SHOULD ALLOW PRECIP TO REDEVELOP/SPREAD 
NORTHWARD INTO SOUTHERN CWA LATE TONIGHT. HAVE UPDATED FORECAST TO 
INCREASE POPS LATE TONIGHT ACROSS FAR SOUTHERN CWA...AS WELL RAISE 
POPS ACROSS SOUTHERN CWA DURING THE MORNING HOURS THURSDAY. 
OTHERWISE THINGS STILL LOOK IN LINE FOR SIGNIFICANT RAINFALL ACROSS 
MUCH OF CWA THURSDAY AFTERNOON/NIGHT...AS COPIOUS AMOUNTS OF 
MOISTURE STREAM NORTHWARD AND COMBINE WITH IMPRESSIVE DYNAMICS/LIFT 
ASSOCIATED WITH EJECTING UPPER TROUGH. 

SEAMAN

.EAX WATCHES/WARNINGS/ADVISORIES...
KS...FLOOD WATCH UNTIL 600 AM CST FRIDAY FOR ZONES KSZ025...KSZ057...
KSZ060...KSZ103>105.

MO...FLOOD WATCH UNTIL 600 AM CST FRIDAY FOR ZONES MOZ020>025...
MOZ028>033...MOZ037>040...MOZ043>046...MOZ053>054.

&&

$$

WFO EAX