Flood in Missouri, May 2, 2006

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO
241 PM CDT MON MAY 1 2006

.DISCUSSION...

SHORT TERM (TONIGHT-WEDNESDAY)...

THE VERTICAL EXTENT OF DRY AIR OVER THE EASTERN PLAINS AND LOWER
MISSOURI VALLEY REGION WAS QUITE EVIDENT IN 12Z RAOBS...THUS
EXPLAINING THE LACK OF CONVECTION DOWNSTREAM FROM A POTENT TROUGH
CURRENT ADVANCING INTO EASTERN KANSAS. SURFACE ANALYSIS DEFINES A
STATIONARY FRONT ACROSS THE OZARK PLATEAU...WITH ONLY SLIGHTLY
BETTER MOISTURE QUALITY TO THE SOUTH. AT THIS JUNCTURE...DONT
BELIEVE WELL SEE MUCH MORE THAN A FEW SPRINKLES/LIGHT SHOWERS
GENERATED FROM MID LEVEL ACCAS BEFORE THIS SYSTEM SHIFTS EAST OF THE
AREA AFTER 00Z.

THEREAFTER...THE FORECAST CONCERNS SURROUND THE THREAT FOR A SERIES
OF CONVECTIVE COMPLEXES PROGGED TO AFFECT THE REGION MID WEEK. GULF
BUOYS SHOW THAT RICH QUALITY MOISTURE HAS BECOME ESTABLISHED ACROSS
THE WESTERN GULF OF MEXICO...WITH SURFACE DEWPOINTS IN THE MID 70S.
DESPITE PERSISTENT ONSHORE FLOW OVER TEXAS...NORTHWARD MOISTURE
TRANSPORT HAS BEEN CONTINUOUSLY IMPEDED BY DOWNWARD MIXING OF SOME
VERY DRY CONTINENTAL AIR. THIS WILL BEGIN TO CHANGE OVER THE NEXT 48
HOURS AS ZONAL FLOW DEVELOPS ACROSS THE CONUS...FINALLY BREAKING
DOWN THE UPPER REX BLOCK AND PERSISTENT RIDGING ALONG THE EASTERN
SEABOARD THAT HAS BEEN LARGELY RESPONSIBLE FOR THE FUNNELING OF DRY
AIR WESTWARD.

A SERIES OF MESOSCALE SHORTWAVES EMBEDDED WITHIN A DOMINANT SOUTHERN
STREAM FLOW...COMBINED WITH A PROGRESSIVE TROUGH ALONG THE
US/CANADIAN BORDER...WILL ACT TO RE-SHARPEN A FRONTAL ZONE FROM THE
TEXAS PANHANDLE NORTHEAST ACROSS MISSOURI INTO THE UPPER MIDWEST.
THIS WILL LIKELY MATERIALIZE AS A REJUVINATION OF THE LOW LEVEL
BAROCLINIC ZONE PRESENTLY ANALYZED IN ROUGHLY THE SAME AREAS...AS
PRESSURE FALLS AND DEEPER SOUTHERLY FLOW IN THE WARM SECTOR ACT TO
REINFORCE THIS BOUNDARY. IF THE NAM/GFS PROGS ARE CORRECT IN THE
QUALITY AND DEPTH OF RETURN MOISTURE...THEN INSTABILITY WILL BE MORE
THAN SUFFICIENT FOR SEVERAL ROUNDS OF DEEP MOIST CONVECTION LATE
TUESDAY NIGHT THROUGH EARLY THURSDAY MORNING. AT THIS POINT...PREFER
THE SLIGHTLY LESS ROBUST GFS PER ITS HANDLING OF INITIALIZED LOW
LEVEL MOISTURE.

ONE CAN ONLY ASSUME BASED ON SYNOPTIC SCALE FLOW REGIME AND WATER
VAPOR IMAGERY THAT THESE EMBEDDED MID LEVEL WEAKNESSES WILL BE
PRESENT...THEREFORE THE TIMING/LOCATION OF CONVECTION IS MERELY A
GENERAL BROADBRUSHING AT THIS JUNCTURE. ACTIVITY MAY PENETRATE SOME
DISTANCE NORTH OF THE SURFACE BOUNDARY GIVEN BREADTH OF ELEVATED
WARM AIR/MOISTURE ADVECTION ACROSS THE PLAINS. A GREATER QUESTION IS
WHEN THE THUNDERSTORM THREAT WILL END...AS GOVERNED BY THE
PROGRESSIVE NORTHERN STREAM TROUGH. IF COOL CANADIAN AIR WITH THIS
FEATURE DOES NOT HAVE THE IMPETUS TO PUSH THIS BOUNDARY SOUTHWARD ON
THURSDAY...THE EVENT MAY ULTIMATELY CONTINUE FURTHER INTO THE MEDIUM
RANGE PERIOD. WITH NUMEROUS RIVERS IN OR APPROACHING FLOOD AS A
RESULT OF THE TWO TO THREE INCH RAINFALL LAST WEEK...THERE IS
OBVIOUSLY GREAT CONCERN FOR POTENTIALLY WIDESPREAD FLOODING GIVEN
THE PROGGED PRECIPITABLE WATERS.

ALTHOUGH PRIMARILY FOCUSED ACROSS THE SOUTHERN PLAINS...THERE IS AN
ADDITIONAL IMPLIED RISK OF SEVERE THUNDERSTORMS ON WEDNESDAY ACROSS
THE SOUTHERN HALF OF THE CWA WHERE GREATER INSTABILITY WILL BE
COUPLED WITH INCREASING SHEAR BENEATH THE UPPER LEVEL WESTERLIES.
THIS WILL BE BETTER FINE TUNED AS MESOSCALE DETAILS ARE RESOLVED.

BOOKBINDER

LONG TERM (THURSDAY-MONDAY)...

ON THURSDAY THE SURFACE FRONT SHOULD BE THROUGH OUR AREA... ALTHOUGH
NOT FAR THROUGH.  GFS IS STILL PRINTING OUT PRECIP DUE TO WEAK
SHORTWAVES MOVING THROUGH IN THE NEARLY ZONAL FLOW AHEAD OF THE NEXT
UPPER LEVEL WAVE.  FOR NOW...HAVE CONTINUED SLIGHT CHANCE POPS IN
THE EXTREME SOUTHERN COUNTIES ON THURSDAY.  THIS FRONT STALLS OUT TO
OUR SOUTH...AND HAVE CONTINUED TO KEEP FRIDAY DRY AS WELL.

FROM THE 06Z GFS...HAD CONSIDERED PUTTING POPS IN FOR SUNDAY NIGHT
AND MONDAY. THIS IS IN ADVANCE OF THE NEXT COLD FRONT. HOWEVER...THE
12Z RUN SEEMS TO HAVE SLOWED THIS FRONT DOWN TO COME THROUGH MONDAY
AND MONDAY NIGHT.  WITH TIMING DIFFERENCES THAT LARGE...AND MONDAY
NIGHT NOT IN THE FORECAST PERIOD...WILL CONTINUE TO KEEP THE END
PERIODS DRY.

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&&

.PREV DISCUSSION...
409 AM...
MESSY WEATHER PATTERN THIS MORNING...WITH ALL SORTS OF WEAK WAVES
MOVING THROUGH FLOW. SHORT WAVE IN SOUTH CENTRAL MISSOURI MOVING
EAST AT THIS TIME. EVEN THOUGH YOU WOULD EXPECT SOME SUBSIDENCE
BEHIND THIS WAVE...THE 06Z NAM SHOWING THAT THE WAVE MOVING INTO
EASTERN NEBRASKA AT THIS TIME HAS A VORT LOBE EXTENSION THAT IS
MOVING INTO WESTERN MISSOURI AND NORTHWEST ARKANSAS. ISENTROPIC LIFT
SHOWING UP ON THE 305K SURFACE THROUGH THIS AREA IS BEST REASON I
CAN FIND FOR THE REDEVELOPMENT OF CONVECTION IN SOUTHWEST MISSOURI.
WILL GO WITH NAM SOLUTION FOR POPS THIS MORNING...AS THIS MODEL
SEEMS TO CAPTURE THESE FEATURES THE BEST.

NEXT PROBLEM IS WITH WAVE CURRENTLY IN CENTRAL COLORADO. THIS SHOULD
BE MOVING INTO CENTRAL KANSAS BY MIDDAY...AND HAVE SOME CONCERNS OF
THUNDERSTORMS DEVELOPING THIS AFTERNOON IN MY SOUTHERN AND EASTERN
AREAS AS THIS WAVE MOVES INTO WESTERN MISSOURI. NAM SHOWING ENOUGH
DRY AIR PUNCHING INTO WESTERN MISSOURI BY MID AFTERNOON THAT
THUNDERSTORM DEVELOPMENT WILL MOST LIKELY TAKE PLACE SOUTH AND EAST
OF FORECAST AREA. GFS NOT QUITE AS BULLISH WITH THIS DRY AIR PUSH.
WILL ONLY GO WITH SOME POPS IN EXTREME SOUTHEASTERN AREAS FOR THIS
AFTERNOON NEAR THE EDGE OF THE THETA E AXIS THAT WILL EXTEND ACROSS
THE SOUTHEASTERN THIRD OF MISSOURI.

TUESDAY SHAPING UP TO BE A PRETTY NICE DAY...WITH WEAK RIDGING
ALOFT. RETURN FLOW AT SURFACE WILL BE SETTING UP AS SURFACE TROUGH
DEVELOPS IN THE NORTHERN PLAINS. THIS BRING MUCH WARMER TEMPERATURES
BACK TO THE REGION.

THIS SURFACE TROUGH IS ASSOCIATED WITH A NORTHERN STREAM SHORT WAVE
THAT WILL BE RACING INTO THE NORTHERN PLAINS TUESDAY NIGHT. SURFACE
COLD FRONT WILL BE MOVING SOUTHEAST OUT OF THE NEBRASKA AND INTO
NORTHWEST MISSOURI BY THE OVERNIGHT PERIOD. AT THE SAME
TIME...WEAKER SHORT WAVE TROUGH SHOWING UP IN SOUTHERN STREAM MOVING
INTO NORTHEAST OKLAHOMA.  CURRENT TRACK IS EXPECTED TO KEEP
CONVECTION WITH THIS WAVE MAINLY SOUTH OF FORECAST AREA...SO OUR
MAIN THREAT FOR RAIN TUESDAY NIGHT AND WEDNESDAY WILL COME WITH
PASSAGE OF COLD FRONT WHICH WILL BE EAST OF FORECAST AREA BY 00Z
THURSDAY. SLIGHTLY COOLER AIR SHOULD DROP IN BEHIND THIS FRONT FOR
THURSDAY AND FRIDAY AS CANADIAN SURFACE HIGH NOSES INTO AREA.

PC

&&

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

WFO EAX

HAZARDOUS WEATHER OUTLOOK...CORRECTED
NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO
554 AM CDT TUE MAY 2 2006

KSZ025-057-060-102>105-MOZ001>008-011>017-020>025-028>033-037>040-
043>046-053-054-031100-
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-
554 AM CDT TUE MAY 2 2006

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

.DAY ONE...TODAY AND TONIGHT

RETURNING MOISTURE WILL INTERSECT A DEVELOPING FRONTAL BOUNDARY
THIS EVENING ACROSS PORTIONS OF EASTERN NEBRASKA THROUGH CENTRAL
KANSAS. SEVERAL DISTURBANCES ALONG THIS FRONT WILL INITIATE
THUNDERSTORMS...WHICH WILL MOVE INTO EASTERN KANSAS AND WESTERN
MISSOURI AS EARLY AS LATE THIS EVENING. THERE IS A SLIGHT RISK OF
SEVERE WEATHER LATE THIS EVENING AND OVERNIGHT...WITH THE PRIMARY
THREATS BEING LARGE HAIL AND HIGH WINDS. THE GREATEST
CONCERN...HOWEVER...IS THE POTENTIAL FOR HEAVY RAINFALL WHICH WILL
AGGRAVATE ONGOING RIVER FLOODING.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

THUNDERSTORMS WILL LIKELY BE ONGOING WEDNESDAY MORNING ACROSS EASTERN
KANSAS AND WESTERN MISSOURI. THE RISK FOR SEVERE WEATHER BY THE
MORNING HOURS WILL BE RELATIVELY LOW...BUT THE FLOODING THREAT WILL
BE HEIGHTENED DUE TO THE ANTECEDENT WET CONDITIONS AND INCREASED
RIVER STAGES.

FURTHER ROUNDS OF THUNDERSTORMS ARE POSSIBLE WEDNESDAY AFTERNOON
ALONG THE AFOREMENTIONED FRONTAL BOUNDARY WHICH IS FORECAST TO STALL
NEAR THE I-70 CORRIDOR. THE THREAT FOR SEVERE WEATHER WEDNESDAY
AFTERNOON WILL BE HIGHLY CONDITIONAL ON THE AMOUNT OF HEATING THAT
CAN BE REALIZED FOLLOWING THE PASSAGE OF THE MORNING THUNDERSTORMS.
IF THE ATMOSPHERE CAN SUFFICIENTLY DESTABILIZE BY PEAK HEATING
WEDNESDAY AFTERNOON...THUNDERSTORMS THAT FORM WILL BE CAPABLE OF
PRODUCING LARGE HAIL AND DAMAGING WINDS...IN ADDITION TO TORRENTIAL
DOWNPOURS CAPABLE OF PRODUCING WIDESPREAD FLOODING.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED LATE THIS EVENING AND OVERNIGHT.

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