Saturday, May 29, 2010

Area Forecast Discussion - South Central/Southwest Missouri

FXUS63 KSGF 300434
NATIONAL WEATHER SERVICE SPRINGFIELD MO
1134 PM CDT SAT MAY 29 2010

..UPDATE TO AVIATION...

..MESOSCALE CONVECTIVE DISCUSSION...

UPDATE...

THE NARROW BAND OF CONVECTION ACROSS FAR SOUTHERN MISSOURI
CONTINUES TO WORK ITS WAY WEST. WITH TIME IT WILL BE RUNNING INTO
AN INCREASINGLY MORE STABLE ATMOSPHERE. THIS WILL LIKELY LEAD TO
WEAKER UPDRAFTS...THOUGH THERE IS ENOUGH MOISTURE FLUX TO KEEP A
FEW SHOWERS GOING THROUGH THE OVERNIGHT HOURS. LIGHTNING HAS BEEN
ON THE DECREASE DURING THE PAST 30 MINUTES...SO IT APPEARS THE
DOWNWARD TREND IS ALREADY STARTING. NEVERTHELESS...A FEW RAIN
SHOWERS WILL MAKE IT TO THE HWY 65 CORRIDOR AND HAVE UPDATED THE
FORECAST ACCORDINGLY.

GAGAN

&&

DISCUSSION...

SHORT TERM (TONIGHT THROUGH MONDAY)...

A CUMULUS FIELD WAS SPREADING WEST ACROSS SOUTH CENTRAL MISSOURI
EARLY THIS AFTERNOON AS LOW LEVEL MOISTURE ADVECTED WESTWARD
AROUND AN UPPER LEVEL LOW CENTERED OVER THE DEEP SOUTH. ISOLATED
CONVECTION CANNOT BE RULED OUT LATER THIS AFTERNOON AND EVENING
ACROSS THE EASTERN OZARKS.

MOISTURE AT ALL LEVELS WILL INCREASE THROUGH SUNDAY AS MOISTURE
ADVECTS INTO THE REGION AROUND THE UPPER LOW RETROGRADING ACROSS
THE DEEP SOUTH. WHILE SYNOPTIC SCALE LIFT WILL BE LACKING
SUNDAY...PRECIPITABLE WATER VALUES CLIMBING TO NEAR 1.5 INCHES WILL
SUPPORT ISOLATED AIRMASS THUNDERSTORMS MAINLY ACROSS SOUTH CENTRAL
MISSOURI.

LATER IN THE DAY SUNDAY INTO SUNDAY NIGHT CONVECTION WILL DEVELOP
ACROSS THE PLAINS AHEAD OF A SLOWLY ADVANCING FRONT. THIS ACTIVITY
MAY IMPACT SOUTHEAST KANSAS INTO CENTRAL MISSOURI LATE SUNDAY
AFTERNOON INTO SUNDAY NIGHT.

A BETTER CHANCE FOR CONVECTION IS IN STORE FOR MEMORIAL DAY AS THE
WEAKENING FRONT SAGS SOUTH INTO THE AREA. MASS CONVERGENCE ALONG
THE FRONT ALONG WITH THE POTENTIAL OF A MINOR SHORTWAVE MIGRATING
ACROSS THE REGION WILL PROVIDE SUPPORT FOR SCATTERED AND PERHAPS
NUMEROUS SHOWERS AND THUNDERSTORMS. THE LACK OF SHEAR AND STRONG
LIFT WILL PRECLUDE A SIGNIFICANT RISK OF SEVERE WEATHER...BUT
ISOLATED STRONG TO SEVERE MULTICELL STORMS WILL BE POSSIBLE.
THE BIGGEST HAZARD WILL BE LIGHTNING GIVEN THE OUTDOOR ACTIVITIES
ON MEMORIAL DAY. TEMPERATURES WILL REMAIN SEASONABLY WARM.

FOSTER

LONG TERM (TUESDAY THROUGH SATURDAY)...

LOWER THAN NORMAL CONFIDENCE IN THE EXTENDED AT THIS POINT...WITH
SIGNIFICANT DIFFERENCES AMONG MODEL SOLUTIONS CONCERNING
EVOLUTION OF SURFACE FEATURES THROUGH THE WEEK.

AT THE START OF THE PERIOD...AN ORPHANED FRONTAL BOUNDARY FROM THE
EARLY WEEK SYSTEM IS EXPECTED TO BE NEARLY STALLED OUT SOMEWHERE
ACROSS THE OZARKS. LEE CYCLOGENESIS IS EXPECTED TO TAKE PLACE OVER
THE COLORADO FRONT RANGE IN RESPONSE TO BROAD TROUGHING OVER THE
INTERMOUNTAIN WEST. AS THIS LOW STRENGTHENS AND MOVES EAST OVER THE
HIGH PLAINS...THE AFOREMENTIONED FRONT IS EXPECTED TO BEGIN LIFTING
NORTH AS A WARM FRONT ACROSS THE AREA TUESDAY. SHOWERS AND
THUNDERSTORMS WILL LIKELY BE ONGOING IN A SCATTERED FASHION WITH
THIS BOUNDARY...BUT SPECIFIC TIMING AND DISTRIBUTION WILL BE HIGHLY
DEPENDENT ON THE EXACT LOCATION OF THE FRONT...WHICH CONTINUES TO BE
DECIDEDLY PROBLEMATIC TO PINPOINT AT THIS DISTANCE. WINDS SHOULD
TURN SOUTH BEHIND THE WARM FRONT...WITH THE GFS AND ECMWF IN BROAD
AGREEMENT IN TAKING THE FRONT NORTH TO IOWA BY WEDNESDAY MORNING.

MODEL SIMILARITIES PRETTY MUCH COME TO AN END AFTER WEDNESDAY
MORNING HOWEVER...AS THE GFS IS INSISTENT ON BARRELING A COLD FRONT
ASSOCIATED WITH THE COLORADO LOW SOUTH ACROSS THE FORECAST AREA
THURSDAY (AND EVENTUALLY DOWN TO THE GULF COAST BY SATURDAY)...WHILE
THE EURO STALLS THE FRONT ACROSS CENTRAL MISSOURI. OBVIOUSLY...THE
EVENTUAL SOLUTIONS OF ESSENTIALLY ALL FORECAST ELEMENTS WILL BE
HIGHLY DEPENDENT ON THE EVOLUTION OF THIS BOUNDARY...AND FORECAST
CONFIDENCE IS QUITE LOW AT THIS POINT AS TO JUST WHAT THAT FINAL
SOLUTION WILL BE. FOR THIS FORECAST I GENERALLY FOLLOWED THE HPC
GUIDANCE...ESPECIALLY BEYOND DAY 5. LATER FORECAST SHIFTS SHOULD BE
ABLE TO LEND FAR MORE DETAIL AND SKILL AS MODEL SOLUTIONS COME INTO
BETTER AGREEMENT OVER THE NEXT FEW DAYS.

BOXELL

&&

AVIATION...

FOR THE 06 TAF PACKAGE...FOR THE MOST PART WILL BE EXPERIENCING
VFR CONDITIONS FOR THE NEXT 24 HOURS. A MORE MOIST AIRMASS IS
WORKING ITS WAY BACK INTO THE AREA. IN FACT A SHRA OR TWO WILL BE
POSSIBLE AT BBG DURING THE OVERNIGHT HOURS. BETTER OPPORTUNITIES
FOR SHRA/TSRA WILL BE DURING PEAK HEATING OF SUNDAY AFTERNOON INTO
SUNDAY EVENING. COVERAGE WILL BE WIDELY SCATTERED SO WILL CONTINUE
TO HANDLE WITH CB AND VC. WILL NEED TO WATCH SHRA/TSRA ALONG A
BOUNDARY THAT WILL EDGE TOWARD THE AREA SUNDAY NIGHT...LATER
FORECASTS CAN REFINE THESE RISKS.

GAGAN

&&

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

$$

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