Flash Flood and Flood in Kansas, March 23 to 24, 2007

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPRINGFIELD MO
1055 AM CDT FRI MAR 23 2007

.UPDATE...

FORECAST UPDATED TO ACCOUNT FOR THE LATEST RADAR TRENDS.

AXIS OF SHRA/TSRA HAS DEVELOPED ALONG A MID/UPPER LEVEL SHEAR AXIS
EXTENDING FROM NE MO THROUGH SE KS AND INTO NE TX. DECENT MOISTURE
TRANSPORT IS NOTED IN THE LOW LEVELS OF THE ATMOSPHERE...WITH
THETA-E RIDGING TO THE TUNE OF 328K NOSING INTO WEST CENTRAL
MISSOURI. THE MOST CONCENTRATED AREAS OF SHRA/TSRA CURRENTLY RESIDES
OVER JASPER COUNTY MO AND CHEROKEE COUNTY MO. ADDITIONAL...MORE
SCATTERED ACTIVITY EXTENDS FARTHER EAST ON THE NE PERIPHERY OF THE
BEST LOW LEVEL MOISTURE TRANSPORT VECTORS (AS VIEWED THROUGH THE
LATEST RUC INITIALIZATIONS).

WITH PWS FROM THE MORNING KSGF SOUNDING AROUND 1.15 INCHES AND KIS
IN EXCESS OF 30...THIS ACTIVITY WILL BE EFFICIENT IN RAINFALL
PRODUCTION. METARS ACROSS SE KS CORRELATE WELL TO 1-HR RAINFALL
RATES. WITH THE RADAR CURRENTLY INDICATING HOURLY RAINFALL AMOUNTS
BETWEEN ONE AND TWO INCHES...A FLASH FLOOD THREAT EXISTS. THE
PRIMARY CONCERN REMAINS EXTREME SE KS AND WESTERN MO WHERE FLASH
FLOOD GUIDANCE VALUES REMAIN LOW FROM RECENT RAINS.

INDICATIONS ARE THAT WHILE THIS AREA OF RAINFALL WILL REMAIN
ELONGATED AND RATHER NARROW...THE SLOW MOVEMENT OF THE SHEAR AXIS
WILL PROMOTE TRAINING CONVECTION IN AN AREA WITH LOWER TOLERANCE FOR
HEAVY RAINFALL AMOUNTS.

ALL PRODUCTS HAVE BEEN UPDATED AND SENT.

GAGAN

&&

.PREVIOUS DISCUSSION...
//303 AM CDT FRI MAR 23 2007//
THE UNSEASONABLY WARM AND UNSETTLED PATTERN WILL PERSIST THROUGH
MUCH OF THE SEVEN DAY FORECAST PERIOD.  UNUSUAL FOR THE TIME OF
YEAR...NO COLD FRONTS OR MAJOR WEATHER SYSTEMS ARE EXPECTED TO PASS
OVERHEAD.  HOWEVER...DUE TO AN EXTENDED PERIOD OF GULF
INFLUX...SCATTERED CLUSTERS OF SHOWERS AND THUNDERSTORMS ARE IN THE
OFFING FOR THE NEXT SEVERAL DAYS.  THEREFORE...THE PRIMARY FORECAST
CONCERN IN THIS MORNINGS ANALYSIS WAS PRECIP CHANCES IN BOTH THE
SHORT AND LONG TERM TIME FRAMES.

ONE ITEM TO NOTE...BECAUSE OF EAST TO NORTHEAST FLOW OVER MUCH OF
THE GULF OF MEXICO...A RATHER HOMOGENEOUS AIRMASS WILL CONTINUE FROM
THE GULF INTO MID AMERICA.  DRY ADVECTION FROM THE ATLANTIC REGIONS
CONTINUE TO LIMIT DEEP RICH MOISTURE FROM MATERIALIZING WITHIN THE
WESTERN GULF SOURCE REGION.  THEREFORE...DESPITE THE LONG PERIOD OF
SOUTHERLY FLOW...INSTABILITY WILL REMAIN UNUSUALLY LIMITED FOR
STRONG TO SEVERE CONVECTION THE NEXT FEW DAYS.

SHORT TERM (TODAY - SUNDAY NIGHT)...
A SYNOPTIC SCALE CYCLONE CENTERED OVER THE BAJA OF CALIFORNIA
CONTINUES TO INFLUENCE THE OVERALL PATTERN OVER THE SOUTHERN PLAINS
AND MISSOURI OZARKS REGION.  A BELT OF SUBTROPICAL MOISTURE EXTENDS
AROUND THE EASTERN FLANK OF THE CYCLONE...AND IS CORRELATED WITH
LARGE SCALE LIFT MAINLY IN THE FORM OF JET STREAM LEVEL DIFFLUENCE.
A FEW CLUSTERS OF CONVECTION WITHIN THE PACIFIC MOISTURE PLUME
APPEAR TO BE CORRELATED WITH ENHANCED AREAS OF UPPER LEVEL
DIFFLUENCE...WHICH IS VERIFIED BY THE SOUTHERN PLAINS PROFILER
NETWORK WHEN ANALYZING 250 MB WIND VECTOR MEASUREMENTS.

ONE OF THESE CONVECTIVE CLUSTERS IS CURRENTLY IMPACTING EXTREME
SOUTHEAST KANSAS AND SOUTHWEST MISSOURI.  DUE TO LIMITED
INSTABILITY...THE PRIMARY HAZARDS WITH THIS CLUSTER APPEARS TO BE
MODERATE TO HEAVY RAIN...ALONG WITH A FEW CLOUD TO GROUND LIGHTNING
STRIKES.  TIMING OF THIS CONVECTIVE CLUSTER AND HOW IT EVOLVES WITH
RESPECT TO AREAL COVERAGE WAS THE INITIAL FORECAST CONCERN FOR
TODAYS PERIOD.

EXTRAPOLATION WITH THE CLUSTERS CURRENT MOVEMENT SUGGESTS THAT AFTER
12Z...THE PRECIPITATION SHIELD WILL BE OVER MUCH OF SOUTH CENTRAL
AND CENTRAL MISSOURI.  RAIN WILL LIKELY END IN THE SPRINGFIELD METRO
AREA SOMETIME BETWEEN 6 - 8AM.  THEREFORE WILL ADJUST MORNING POPS
TO REPRESENT THIS EXTRAPOLATION...WITH LIKELY TO CATEGORICAL POPS
OVER THE EASTERN HALF OF THE CWA...THEN TAPERING THE GRID TO SLIGHT
CHANCES OUT WEST.  ITS LIKELY THAT THE CLUSTER WILL LOSE SOME OF
ITS LOW LEVEL FORCING WITH NOCTURNAL VEERING OF LOW LEVEL WINDS.

BOTH THE WRF AND THE GFS INDICATE A SECOND CLUSTER OF CONVECTION TO
IMPACT THE OZARKS THIS AFTERNOON.  AGAIN...THE ONLY KINEMATIC
MECHANISM TO CAUSE THIS APPEARS TO BE AN AREA OF ENHANCED UPPER
DIFFLUENCE CURRENTLY BECOMING MORE ORGANIZED NEAR ABILENE TEXAS.
HOW THIS FORECASTED BAND OF FORCING WILL IMPACT THE OZARKS REMAINS
VERY QUESTIONABLE.  QPF FIELDS FROM THE WRF AND GFS ARE VERY
INCONSISTENT AND NOT IMPRESSIVE AT ALL.  HOWEVER MOS GUIDANCE
SUGGEST CATEGORICAL POPS IN ALL LOCATIONS.

WILL ADJUST THE AFTERNOON POP GRID TO 50 POPS DUE TO THE UNCERTAINTY
ON HOW THIS EVOLVES.  ONE ELEMENT THAT WE DO KNOW FOR SURE IS THAT
CONSIDERABLE CLOUD COVER WILL EXIST THROUGH THE ENTIRE DAY...WHICH
WILL HAVE SOME IMPACTS ON TEMPERATURES.  WITH EARLY MORNING
TEMPERATURES STARTING OUT IN THE LOW TO MID 60S...DESPITE CLOUD
COVER AND PRECIP READINGS SHOULD WARM INTO THE 70S IN MOST
LOCATIONS.

HEADING INTO THE WEEKEND...THE BAJA LOW WILL FILL WHILE THE MAIN
CIRCULATION SHIFTS INTO THE HIGH PLAINS.  MASS AND MOISTURE FIELDS
FROM THE GFS INDICATE THAT THE AXIS OF SUBTROPICAL MOISTURE SHIFTS
EAST OF THE CWA...HOWEVER...LOW LEVEL JET AND WARM CONVEYOR BELT
PROCESSES OCCUR BY SATURDAY MORNING.  THIS WILL YIELD MORE AREAS OF
CONVECTIVE CLUSTERS SOMEWHERE ALONG THE SOUTHERN/CENTRAL PLAINS
CORRIDOR.  RESIDUAL CLUSTERS WILL LIKELY SHIFT EASTWARD DURING THE
DAY ON SATURDAY...POSSIBLY IMPACTING THE CWA.  WILL KEEP ONGOING
THUNDERSTORM CHANCES GOING IN THE GRIDS DUE TO SIGNALS FROM BOTH THE
GFS AND WRF FOR INCREASED INSTABILITY WITHIN THIS PERIOD.

NOT MUCH CHANGE IN THE LARGE SCALE PATTERN CAN BE ANALYZED WITHIN
MODEL DATA.  THEREFORE SINCE WE WILL REMAIN UNDER THIS EXTENDED
WARM/MOISTURE ADVECTION REGIME...WILL KEEP THUNDERSTORM CHANCES
GOING THROUGH SUNDAY NIGHT.

LONG TERM (MONDAY - THURSDAY)...
AN UPPER LEVEL WEAKNESS...BASICALLY THE RESIDUAL TROUGHING FROM THE
ONGOING BAJA CYCLONE IS SUGGESTED TO GRADUALLY PASS THROUGH THE AREA
MONDAY OR TUESDAY.  NOT MUCH OF A RESPONSE OCCURS AT THE SURFACE AS
THE OZARKS REMAINS UNDER SOUTHERN FLOW.  COOLING ALOFT MAY PROMOTE
INCREASED INSTABILITY...ESPECIALLY TUESDAY AFTERNOON.  WILL KEEP
ONGOING TSTORM CHANCES ON TUESDAY LOOK GOOD AND MADE LITTLE CHANGE.

MEDIUM RANGE MODELS INDICATE THAT LONG WAVE TROUGHING WILL REDEVELOP
ACROSS THE WESTERN THIRD OF THE CONUS.  THIS WILL REINFORCE THE
UNSETTLED PATTERN AND OFFER A CONTINUATION OF UNSEASONABLY WARM
TEMPERATURES.  I MADE A FEW ADJUSTMENTS TO TEMPERATURES BY WARMING
THESE GRIDS BY SEVERAL DEGREES IN THE EXTENDED.  ECMWF HAS BEEN
PERFORMING THE BEST OVER THE PAST FEW WEEKS...WHICH SHOWS ENERGY
APPROACHING THE NATIONS MID SECTION BY THURSDAY.  THE GFS IS NOT
MUCH DIFFERENT WITH A SIMILAR SOLUTION.  THEREFORE NO ADJUSTMENTS TO
THESE ONGOING THUNDERSTORM CHANCES WERE NEEDED.

CRAMER

&&

.AVIATION...

TAF SITES WERE AMENDED EARLIER TO GAUGE RAINFALL/TS TIMING. IT
APPEARS THAT CIGS/VIS WILL WAVER FROM VFR TO MVFR WITH THE ON
AGAIN...OFF AGAIN HEAVIER CONVECTIVE ELEMENTS. RAINFALL WILL PERSIST
AT JLN INTO THE EARLY AFTERNOON. AT SGF...CONFIDENCE IS A LITTLE
LOWER IN TIMING DUE TO THE SLOW EASTWARD DRIFT OF CONVECTION...AN
ESTIMATED TIMING IS PROVIDED IN THE LATEST TAF TARGETING THE EARLY
TO MID AFTERNOON HOURS.

GAGAN

&&

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

WFO SGF

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE SPRINGFIELD MO
957 AM CDT FRI MAR 23 2007

KSZ073-097-101-MOZ055>058-066>071-077>083-088>098-101>106-241045-
BOURBON-CRAWFORD-CHEROKEE-BENTON-MORGAN-MILLER-MARIES-VERNON-
ST. CLAIR-HICKORY-CAMDEN-PULASKI-PHELPS-BARTON-CEDAR-POLK-DALLAS-
LACLEDE-TEXAS-DENT-JASPER-DADE-GREENE-WEBSTER-WRIGHT-NEWTON-
LAWRENCE-CHRISTIAN-DOUGLAS-HOWELL-SHANNON-MCDONALD-BARRY-STONE-
TANEY-OZARK-OREGON-
957 AM CDT FRI MAR 23 2007

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF THE MISSOURI
OZARKS AND EXTREME SOUTHEAST KANSAS.

.DAY ONE...TODAY AND TONIGHT.

  WEATHER HAZARDS EXPECTED:

 THUNDERSTORMS CONTAINING HEAVY RAIN AND CLOUD TO GROUND LIGHTNING.

  AREAS AFFECTED AND TIMING:

 NUMEROUS SHOWERS AND THUNDERSTORMS WILL IMPACT LOCATIONS ACROSS
 EXTREME SOUTHEAST KANSAS AND THE MISSOURI OZARKS...GENERALLY ALONG
 AND NORTHWEST OF A LINE ANDERSON TO ROLLA.

  DISCUSSION:

 A LARGE AREA OF LOW PRESSURE IN THE UPPER LEVELS OF THE ATMOSPHERE
 CONTINUES TO ALLOW  GULF MOISTURE TO SPREAD INTO THE REGION.  IN
 RESPONSE...SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE THROUGH
 TODAY.  DUE TO THE LIMITED AMOUNT OF INSTABILITY AVAILABLE...SEVERE
 WEATHER IS NOT EXPECTED. ISOLATED AREAS OF FLOODING ARE POSSIBLE...
 PARTICULARLY ACROSS EXTREME SOUTHEAST KANSAS AND PORTIONS OF
 WESTERN MISSOURI.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY.

 SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE ON A DAILY BASIS
 THROUGH NEXT THURSDAY. THE LATEST FORECAST ANALYSIS SUGGEST THAT
 THERE ARE NO STRONG INDICATORS FOR ORGANIZED SEVERE WEATHER.

.SPOTTER INFORMATION STATEMENT...

  SPOTTER ACTIVATION WILL NOT BE NEEDED THROUGH TONIGHT.

&&

THIS PRODUCT IS NOW AVAILABLE IN GRAPHICAL FORMAT...ALONG WITH
OTHER WEATHER...HYDROLOGICAL AND CLIMATE INFORMATION...AT
HTTP://WWW.CRH.NOAA.GOV/SGF(ALL LOWERCASE)

GAGAN/CRAMER