Wednesday, April 28, 2010

Area Forecast Discussion - South Central/Southwest Missouri

FXUS63 KSGF 280803
NATIONAL WEATHER SERVICE SPRINGFIELD MO
303 AM CDT WED APR 28 2010

DISCUSSION...

A BIG CHANGE IN THE WEATHER PATTERN WILL OCCUR OVER THE NEXT
COUPLE OF DAYS AS NORTHWEST FLOW ALOFT TRANSITIONS TO
SOUTHWESTERLY. THIS WILL RESULT IN A BIG WARMING TREND THE NEXT
FEW DAYS...ALONG WITH INCREASING CHANCES FOR THUNDERSTORMS.
TEMPERATURES WERE THE MAIN SHORT TERM FORECAST CONCERN. ATTENTION
THEN TURNS TO POPS...ALONG WITH THE POTENTIAL FOR SEVERE STORMS
AND FLOODING LATE THIS WEEK.

AN UPPER LEVEL RIDGE WILL SLIDE EAST ACROSS THE REGION TODAY WITH
HEIGHTS QUICKLY FALLING ACROSS THE NORTHERN AND CENTRAL ROCKIES.
THIS WILL RESULT IN A RETURN SOUTHERLY FLOW SETTING UP ACROSS THE
PLAINS AND OZARKS. BESIDES BRISK AND GUSTY SOUTHERLY WINDS...TODAY
LOOKS PLEASANT WITH HIGHS FROM THE UPPER 60S TO MIDDLE 70S. EVEN
WARMER CONDITIONS ARE EXPECTED ON THURSDAY AS 850 MB TEMPERATURES
ARE STILL PROGGED TO WARM INTO THE MIDDLE TEENS CELSIUS.
CONDITIONAL CLIMATOLOGY FOR LATE APRIL INDICATES THIS SHOULD
RESULT IN UPPER 70S AND LOWER 80S FOR HIGHS. THE BIGGER STORY FOR
THURSDAY WILL BE WIND. PRESSURE GRADIENTS ALONE SUPPORT WIND
MEETING OR EXCEEDING WIND ADVISORY CRITERIA ACROSS WESTERN
MISSOURI AND SOUTHEAST KANSAS. GUSTS TO 45 MPH ALSO SEEM PLAUSIBLE
WITH DECENT MIXING EXPECTED. A WIND ADVISORY WILL BE NEEDED IF
THESE EXPECTED CONDITIONS HOLD TRUE.

HEIGHT FALLS WILL THEN BEGIN TO OVERSPREAD THE OZARKS FROM
THURSDAY INTO THURSDAY NIGHT AS A LARGE UPPER LEVEL LOW MEANDERS
EAST ACROSS THE NORTHERN ROCKIES. MODELS ALSO CONTINUE TO DEPICT A
SHORT WAVE TROUGH COMING AROUND THE SOUTHERN FLANK OF WHAT WILL BE
A LARGE UPPER LEVEL TROUGH OVER THE WESTERN UNITED STATES. THIS
SHORT WAVE WILL EFFECTIVELY BEGIN TO DRIVE A COLD FRONT EAST
TOWARDS THE MISSOURI OZARKS THURSDAY NIGHT. A FEW MODELS ARE
BREAKING OUT PRECIPITATION WELL AHEAD OF THE FRONT AS A STRONG LOW
LEVEL JET DEVELOPS ACROSS THE REGION. NOT QUITE BUYING THIS
SCENARIO YET AS THERE WILL BE QUITE A BIT OF WARM AND DRY AIR TO
OVERCOME IN THE MID LEVELS.

MODELS CONTINUE TO INDICATE THAT FRIDAY MAY BE AN ACTIVE DAY
ACROSS THE REGION. THAT FRONT SHOULD CONTINUE TO PROGRESS EAST
INTO THE MISSOURI OZARKS. MODELS ALSO INDICATE A WEAK SURFACE LOW
MOVING NORTHEAST UP THE FRONT...WITH A DRY LINE TRAILING THE LOW
INTO EASTERN KANSAS AND OKLAHOMA. THE AMOUNT OF QUALITY MOISTURE
RETURN AND INSTABILITY CONTINUE TO BE BIG QUESTIONS. MODEL
CONSENSUS AT THIS TIME IS TO BRING AT LEAST 1000 J/KG OF MLCAPE
INTO OUR GENERAL VICINITY. MEANWHILE...THE SYNOPTIC REGIME WILL
FAVOR FAIRLY STRONG DEEP LAYER SHEER. WITH THIS SAID...SEVERE
STORMS ARE A CONCERN. WILL BE INCREASING THE SEVERE STORM RISK
LEVEL INTO THE ELEVATED CATEGORY IN THE HAZARDOUS WEATHER OUTLOOK.
AS WAS THE CASE YESTERDAY...IF CONFIDENCE INCREASES IN HIGHER
AMOUNTS OF INSTABILITY...THE RISK LEVEL MAY NEED TO BE INCREASED.

MODELS CONTINUE TO STRUGGLE WITH THE ACTUAL POSITION OF THE FRONT
THIS WEEKEND AND EARLY NEXT WEEK. THE SYNOPTIC PATTERN CONTINUES
TO SUPPORT THE FRONT NOT MAKING ALL THAT MUCH PROGRESS SOUTH AND
EAST. ON THE OTHER HAND...CONVECTIVE/COLD POOL PROCESSES MAY BE A
MUCH BIGGER PLAYER IN FRONTAL POSITION. THIS WILL THEREFORE BE A
SHORT TERM FORECAST ISSUE. UNTIL THAT TIME...MAINTAINED CHANCE
POPS THROUGH THE WEEKEND. WITH MULTIPLE ROUNDS OF CONVECTION QUITE
POSSIBLE...WILL CONTINUE WITH A LIMITED FLOODING THREAT IN THE
HAZARDOUS WEATHER OUTLOOK. THOSE WITH OUTDOOR PLANS THIS WEEKEND
SHOULD KEEP UP WITH THE FORECAST AS THESE FINER DETAILS WILL HAVE
A HUGE IMPACT ON SENSIBLE WEATHER.

THE EARLY NEXT PERIOD GETS NO EASIER AS WE WILL LIKELY REMAIN IN A
WEST TO SOUTHWEST FLOW ALOFT. SLIGHT TO LOW END CHANCE POPS WERE
MAINTAINED FOR THIS PERIOD. TEMPERATURES THIS WEEKEND AND EARLY
NEXT WEEK WILL BE HIGHLY DEPENDENT ON THE FRONTAL POSITION AND
CLOUD COVER. GENERALLY KEPT HIGHS IN THE MIDDLE 70S WITH LOWS FROM
THE MIDDLE 50S TO LOWER 60S.

SCHAUMANN

&&

AVIATION...

PILOTS FLYING IN AND OUT OF THE SOUTHWEST MISSOURI AIRPORTS CAN
EXPECT VFR CONDITIONS OVER THE NEXT 24 HOURS.

WINDS WILL CONTINUE LIGHT AND VARIABLE THROUGH THE NIGHT AS A HIGH
PRESSURE AXIS MOVES OVERHEAD. WIND SPEEDS WILL INCREASE WEDNESDAY
MORNING AND EVEN BECOME GUSTY WEDNESDAY AFTERNOON AND EVENING. LOOK
FOR GUSTS FROM THE SOUTH UP TO 25 KNOTS AT TIMES. THE HIGHEST GUSTS
WILL LIKELY OCCUR OVER THE JOPLIN AIRPORT...WITH LOWER GUSTS
EXPECTED AT THE BRANSON AIRPORT.

THE SOUTHWEST MISSOURI SKY IS FORECASTED TO REMAIN CLEAR THROUGH
MOST OF THE NEXT 24 HOURS.

NO OBSTRUCTIONS TO VISIBILITIES ARE EXPECTED.

CRAMER

&&

FIRE WEATHER...

AFTERNOON RELATIVE HUMIDITIES ARE EXPECTED TO DROP INTO THE 30 TO
35 PERCENT RANGE THE NEXT FEW AFTERNOONS. FEEL THAT MODELS ARE
SLIGHTLY OVERDOING AMOUNTS OF MOISTURE RETURN IN AN INCREASING
SOUTHERLY FLOW...BUT EVAPOTRANSPIRATION WILL COMPENSATE SOMEWHAT.
WINDS WILL INCREASE OUT OF THE SOUTH AND BECOME GUSTY TODAY...WITH
EVEN STRONGER WINDS EXPECTED THURSDAY. SEVERAL CALLS WERE MADE OUT
TO THE FIELD YESTERDAY...INCLUDING THE DEPARTMENT OF CONSERVATION
AND MARK TWAIN NATIONAL FOREST PERSONNEL. THE RESOUNDING THEME WAS
THAT THE VAST MAJORITY OF FUELS WERE MOIST. NO HEADLINES ARE
THEREFORE PLANNED AT THIS TIME...DESPITE THE EXPECTED
METEOROLOGICAL CONDITIONS. WILL CONTINUE TO HIT FIRE WEATHER
CONCERNS IN THE HAZARDOUS WEATHER OUTLOOK.

SCHAUMANN

&&

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

$$

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