Flash Flooding and Flooding in Missouri, May 5 to 20, 2007

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO
904 PM CDT SAT MAY 5 2007

.DISCUSSION...
WILL EXPAND CHANCE OF STORMS FURTHER EAST FOR THE OVERNIGHT HOURS.
CONCERNED WITH SEEING SOME COOLING ALOFT AS 700 THERMAL RIDGE BREAKS
DOWN A BIT. SEEING THETA E ADVECTION TAKING PLACE INTO WESTERN HALF
OF MISSOURI AND LOW LEVEL JET...THOUGH FOCUSED MORE IN
KANSAS...BEING A FACTOR IN WESTERN PORTIONS OF FORECAST AREA.

PC

&&

.PREVIOUS DISCUSSION...
/344 PM CDT SAT MAY 5 2007/
ACTIVE DAY ACROSS THE PLAINS AS DEEP UPPER TROUGH EDGES EASTWARD
ACROSS THE ROCKIES. H5 PROFILER DATA SHOWING IMPRESSIVE 50-80KT JET
STRETCHING FROM CENTRAL NEBRASKA SOUTHWARD INTO NORTHERN TEXAS.
CONVECTION HAS INITIATED FAIRLY EARLY ALONG AND AHEAD OF THE DRYLINE
CURRENTLY EXTENDING FROM JUST EAST OF NORTH PLATTE SOUTHWARD TO HILL
CITY TO DODGE CITY. CURRENTLY THINKING MOST OF THE CONVECTION THROUGH
THE REMAINDER OF THIS AFTERNOON WILL REMAIN FARTHER WEST ACROSS
CENTRAL KANSAS.

ACROSS OUR NECK OF THE WOODS...SFC ANALYSIS SHOWING ILL DEFINED
PSEUDO WARM FRONT DRAPED ACROSS THE CWA. DECENT CONVERGENCE ALONG THE
BOUNDARY WITH SFC WINDS AT KSGF AND KAIZ DUE SOUTH LEADING INTO EAST-
SOUTHEASTERLY FLOW FROM KANSAS CITY TO SEDALIA TO JEFFERSON CITY.
LATEST VIS SAT IMAGE SHOWING SEVERAL CONVECTIVE ROLLS ACROSS THE AREA
WITH DECENT CU FIELD EVIDENT. HOWEVER...18Z TOP SOUNDING SHOWING
CAPPING INVERSION REMAINS PRESENT ACROSS THE AREA INHIBITING
CONVECTIVE INITIATION. IN ADDITION...LATEST RUC ANALYSIS REVEALING H7
THERMAL AXIS NOSING INTO EXTREME EASTERN KANSAS AND SHOULD OVERSPREAD
THE AREA THROUGH THE REMAINDER OF THE AFTERNOON. THIS WILL LIKELY
KEEP ANY CONVECTION AT BAY LIMITING PRECIP CHANCES THROUGH THE
AFTERNOON AND EARLY EVENING HOURS.

ATTENTION THEN TURNS TO CONVECTIVE POTENTIAL OVERNIGHT TONIGHT WITH
ACTIVITY FURTHER WEST. WITH DEEP MERIDIONAL FLOW ACROSS MOST OF THE
PLAINS...STORM MOTIONS HAVE FAVORED A MORE NORTH TO NORTH-NORTHEAST
DIRECTION THUS FAR TODAY. MODEL PROGS CONTINUE THIS TREND AS UPPER
TROUGH ELONGATES ALONG THE EASTERN EXTENT OF THE ROCKIES OVERNIGHT.
FIRST THOUGHT WAS TO REMOVE MENTION OF POPS ACROSS THE WESTERN CWA
BASED ON THESE TRENDS. HOWEVER...WITH NEW CONVECTION FORMING WELL
AHEAD OF THE DRYLINE ACROSS CENTRAL KANSAS...DECIDED TO KEEP POPS
GOING OVERNIGHT MAINLY FOCUSED ACROSS THE NORTHWESTERN COUNTIES.
SLIGHT RISK REMAINS IN EFFECT FOR EXTREME NORTHWEST TIP OF MISSOURI
AND EXTREME NORTHEAST KANSAS...AND CANT RULE OUT LARGE HAIL AND
STRONG WINDS WITH ANY ACTIVITY THAT MAKES IT THIS FAR EAST.

DEEP UPPER TROUGH REMAINS ANCHORED ACROSS THE EASTERN ROCKIES DURING
THE DAY TOMORROW AS AMPLIFIED RIDGING TAKES SHAPE FROM THE GREAT
LAKES TO THE GULF COAST. THIS WILL LIKELY LEAD TO A REPEAT
PERFORMANCE AS SEEN TODAY WITH THE DRYLINE LIKELY BEING THE FOCUS FOR
INITIATION ACROSS WESTERN AND CENTRAL KANSAS ONCE AGAIN. THINKING SVR
POTENTIAL WILL AGAIN BE HIGHLY CONDITIONAL ON ACTIVITY FURTHER WEST
MAKING EASTWARD PROGRESS INTO EASTERN KANSAS/WESTERN MISSOURI. IF IT
DOES MAKE IT THIS FAR...AGAIN LARGE HAIL AND DAMAGING WINDS WILL BE
POSSIBLE. OTHERWISE...POINT FORECAST SOUNDINGS SHOWING LESS CAPPING
ACROSS THE AREA TOMORROW OWING TO A BETTER CHANCE OF PRECIP
DEVELOPMENT....HOWEVER..LAPSE RATES AND SHEAR ARE MARKEDLY WEAKER
ACROSS MISSOURI. NEVERTHELESS...SHOULD SEE SIMILAR THERMODYNAMICS
REMAIN IN PLACE AS SEEN TODAY CREATING DECENT INSTABILITY AGAIN
TOMORROW. THEREFORE...KEPT MENTION OF CHC POPS TOMORROW AFTERNOON
THROUGH THE BEGINNING OF THE WEEK WITH UPPER SYSTEM ONLY SLOWLY
EDGING EASTWARD.

MODEL PROGS CONTINUE TO INDICATE HIGH QPF FIELDS BY THE BEGINNING TO
THE WEEK. THIS IN COMBINATION WITH HIGH PW VALUES MAY LEAD TO SOME
HYDRO CONCERNS DURING THIS TIME FRAME. WILL CONTINUE TO MONITOR
TRENDS AS THE SITUATION EVOLVES.

DEROCHE

EXTENDED FORECAST...

AS TO BE EXPECTED...THE MEDIUM RANGE FORECAST REMAINS VERY
MUDDY...ESPECIALLY IN THE TUESDAY/WEDNESDAY TIME FRAME AS MOST
METEOROLOGICAL VARIABLES WILL BE CONTROLLED BY THE EVOLUTION OF
MESO/STORM-SCALE FEATURES IN THE DAY 2-3 TIME FRAME.

SYNOPTICALLY...THIS TIME FRAME LOOKS VERY WET AS PROGRESSION OF
UPPER RIDGE INTO THE EASTERN US ALLOWS SOUTHWESTERLY UPPER FLOW TO
STRENGTHEN AHEAD OF BROAD LONGWAVE TROUGHING ACROSS THE HIGH PLAINS.
MID-UPPER LEVEL HEIGHT FALLS...CORRESPONDING TO THE REMOVAL OF ANY
REMAINING CAP...WILL ALLOW A VERY MOIST AND WEAKLY UNSTABLE AIRMASS
TO CONVECT OUT WITH LITTLE DIFFICULTY AS SEVERAL SHORTWAVE ROTATE
NORTHEAST ACROSS THE AREA.

SUFFICIENT SHEAR MAY POSE A THREAT FOR SEVERE WEATHER
TUESDAY...ALTHOUGH I THINK THAT INSOLATION WILL BE LIMITED WITH
ABUNDANT CLOUD COVER AND THREAT FOR WIDESPREAD ANTECEDENT
THUNDERSTORMS. IN FACT...HEAVY RAINFALL BETWEEN TOMORROW AND THE
UPPER TROUGH PASSAGE EARLY FRIDAY LOOKS TO BE THE MAIN CONCERN --
AND POTENTIALLY A BIG ONE. QUALITY LOW LEVEL MOISTURE FOR EARLY MAY
IS ALREADY IN PLACE AND THE COLLECTIVE EFFECTS OF POTENTIALLY 5 DAYS
OF THUNDERSTORM ACTIVITY WILL LIKELY DELIVER SEVERAL INCHES OF
RAINFALL OVER A WIDESPREAD AREA DURING THE PERIOD. HAVING JUST
EXITED ONE RECENT WET PERIOD WITH LITTLE IN-BETWEEN BREAK...WILL
LIKELY ISSUE AN ESF FOR THE PERIOD HIGHLIGHTING HEAVY RAIN/FLOOD
POTENTIAL INTO NEXT WEEK.

TEMPERATURES WILL BE EXTREMELY DIFFICULT GIVEN THE ENVIRONMENT. WE
MAY NOT END UP MUCH WARMER THAN UPPER 60S/LOWER 70S ON A FEW OF
THESE DAYS. DID BUMP UP LOWS/DEWPOINTS AS MOISTURE CONTENT SHOULD
CHANGE LITTLE DURING THE TUESDAY-THURSDAY TIME FRAME.

BOOKBINDER

&&

.AVIATION...
/645 PM CDT SAT MAY 5 2007/
DIURNAL CU FIELD BEGINNING TO DISSIPATE THIS EVENING AS CIRRUS BLOW
OFF OVERSPREADS TERMINALS. MORE EXTENSIVE VFR 7K FT DECK EXPECTED TO
ADVECT INTO TERMINALS IN THE NEXT SEVERAL HOURS. LARGEST UNCERTAINTY
CONCERNS THE EASTWARD PROPAGATION OF TSTMS ACROSS CNTRL KANSAS. HAVE
TRIED TO TIME ONSET VCTS AFTER MIDNIGHT...HOWEVER GIVEN JET
ENERGY...FOCUSING MECHANISMS AND MOST FAVORABLE ATMOSPHERE REMAINING
WEST OF THE AREA...FEEL ANY THUNDER ACTIVITY WILL BE IN A RAPIDLY
DISSIPATING STAGE AS THEY APPROACH TERMINALS. CONTINUED PRESENCE OF
MVFR CIGS DURING THE MORNING HOURS AS LOW LEVEL MOISTURE DIURNALLY
SATURATES A 2-3K FT RANGE. HAVE NOT ADDED ANY PRECIP FOR TOMORROW
AFTERNOON...THOUGH THIS MAY NEED TO BE ADDED IN FUTURE TAFS.

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&&

.EAX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO
839 PM CDT SAT MAY 5 2007

KSZ025-057-060-102>105-MOZ001>008-011>017-020>025-028>033-037>040-
043>046-053-054-070145-
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-
839 PM CDT SAT MAY 5 2007

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

.DAY ONE...TONIGHT

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER NORTHWEST
MISSOURI AND EXTREME NORTHEAST KANSAS TONIGHT. SCATTERED
THUNDERSTORMS DEVELOPING OVER NORTHWEST MISSOURI TONIGHT WILL BE CAPABLE
OF LARGE HAIL...DAMAGING WINDS AND ISOLATED TORNADOES.

IN ADDITION...ISOLATED THUNDERSTORMS HAVE DEVELOPED ACROSS EASTERN
KANSAS MOVING TOWARDS THE NORTH. IF THESE STORMS CAN PERSIST...A SEVERE
THREAT WOULD INCREASE ACROSS EXTREME EASTERN KANSAS AND WESTERN
MISSOURI TONIGHT INCLUDING THE KANSAS CITY METRO AREA. THE MAIN
THREAT WITH THIS ACTIVITY WILL BE LARGE HAIL AND DAMAGING WINDS.
HOWEVER...WITH INCREASING WIND FIELD ACROSS THE REGION...AN ISOLATED
TORNADO THREAT WILL ALSO BE POSSIBLE.

.DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY

SCATTERED THUNDERSTORMS ARE POSSIBLE SUNDAY AND SUNDAY EVENING AS THE
HIGH PLAINS UPPER SYSTEM CONTINUES A SLOW NORTHEAST SHIFT. THE
PRIMARY SEVERE THREAT ON SUNDAY WILL LIKELY EXIST FARTHER WEST ACROSS
CENTRAL KANSAS. THIS ACTIVITY MAY PUSH INTO EXTREME EASTERN KANSAS
AND WESTERN MISSOURI DURING THE EVENING AND OVERNIGHT HOURS.

THUNDERSTORMS WILL BE POSSIBLE AGAIN MONDAY THROUGH WEDNESDAY ACROSS
THE FORECAST AREA. STORMS MAY BECOME STRONG TO SEVERE DURING THIS TIME
PERIOD CAPABLE OF PRODUCING LARGE HAIL AND DAMAGING WINDS.
HOWEVER..IT REMAINS TOO EARLY TO DETERMINE A SPECIFIC REGION FOR ANY
SEVERE ACTIVITY. IN ADDITION...HEAVY RAINFALL WILL BE POSSIBLE DURING
THIS TIME FRAME LEADING TO THE POSSIBILITY OF LOCALIZED FLOODING.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED TONIGHT ACROSS EASTERN KANSAS AND
WESTERN MISSOURI. SPOTTER ACTIVATION MAY ALSO BE NEEDED AGAIN ON
SUNDAY EVENING MAINLY OVER NORTHWEST AND WEST CENTRAL MISSOURI AND
EXTREME EAST CENTRAL KANSAS.

DEROCHE

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO
820 PM CDT SAT MAY 5 2007

MOZ001-060145-
ATCHISON-
820 PM CDT SAT MAY 5 2007

...SIGNIFICANT WEATHER ALERT FOR CENTRAL ATCHISON COUNTY UNTIL 845 PM
CDT...

AT 816 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A
STRONG THUNDERSTORM 5 MILES SOUTH OF FAIRFAX...OR 17 MILES SOUTH OF
TARKIO...MOVING NORTH AT 35 MPH.

THIS STORM WILL BE NEAR...
  TARKIO AND 6 MILES EAST OF ROCKPORT BY 835 PM CDT.

THE TOWN OF WESTBORO IS ALSO IN THE PATH OF THIS STORM.

NICKEL SIZE HAIL IS EXPECTED WITH THIS STORM.

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