Friday, November 5, 2010

Area Forecast Discussion - South Central/Southwest Missouri

FXUS63 KSGF 050500
AFDSGF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPRINGFIELD MO
1200 AM CDT FRI NOV 5 2010

..UPDATE TO AVIATION...

DISCUSSION...

FORECAST TO BE ACTIVE THROUGHOUT THIS FORECAST PERIOD...WITH
NUMEROUS MODERATE TO HIGH IMPACT EVENTS. CONFIDENCE HIGH GIVEN
MODEL RUN TO RUN AND 12Z MODEL TO MODEL CONSISTENCY.

SHORT TERM...TODAY THROUGH SATURDAY...

NORTHERLY LOW LEVEL TRAJECTORY CONTINUES TO DRAW COOLER AND DRIER
COLUMN INTO THE OZARKS. STRONG MIXING THIS AFTERNOON HAS DROPPED
SURFACE DEW POINTS INTO THE MIDDLE 20S TO LOWER 30S...RESULTING IN
HUMIDITIES IN THE LOWER TO MIDDLE 20S ACROSS THE REGION. THIS
COMBINED WITH 20 TO 30 MPH SURFACE WINDS LEAD TO SIGNIFICANT
CONCERN FOR THE SPREAD OF FIRES THROUGH SUNSET. SHORT FUSE RED
FLAG WARNING HAS BEEN ISSUED TO HIGHLIGHT CONCERNS.

ATTENTION THEN TURNS TO TONIGHT WHERE NORTHERN TRAJECTORIES AND
APPROACH OF HIGH PRESSURE TO LIKELY END GROWING SEASON OVER
SOUTHEAST KANSAS TONIGHT. WINDS TO DIMINISH LATER THIS EVENING
AND RADIATIONAL COOLING ALLOWS TEMPERATURES TO REACH THE UPPER 20S
TO AROUND 30. A FREEZE WARNING HAS BEEN ISSUED FOR SOUTHEAST
KANSAS...THOUGH FREEZING CONDITIONS ARE ALSO EXPECTED OVER THE
REST OF THE FORECAST AREA WHICH HAD PREVIOUSLY WITNESSED A HARD
FREEZE A WEEK AGO.

STILL COLDER READINGS ARE THEN EXPECTED FRIDAY NIGHT AS THE
CENTER OF THE HIGH APPROACHES WHICH WILL ADD TO THE CERTAINTY FOR
THE SEASONAL END OF ALL UNPROTECTED PLANT GROWTH.

FIRE WEATHER CONCERNS WILL BE MINIMIZED ON FRIDAY AS WEAKER WINDS
AND COOLER HIGH TEMPERATURES OFFSET DRY CONDITIONS. THIS THREAT THOUGH
WILL BE BACK ON THE INCREASE SATURDAY AS UPPER RIDGE BEGINS TO
BUILD INTO THE CENTRAL PLAINS WARMING HEIGHTS AND WINDS SHIFT TO
THE SOUTH AS THE SURFACE HIGH DEPARTS EAST. THIS WILL BRING
WARMING TEMPERATURES BUT LITTLE MOISTURE.

LONG TERM...SUNDAY THROUGH THURSDAY

SURFACE GRADIENT WILL SIGNIFICANTLY INCREASE ON SUNDAY AS LEE
TROUGHING DEVELOPS AHEAD OF APPROACHING MEAN TROUGH. HAVE FOLLOWED
EARLIER FORECAST THINKING THAT SLOWED THE RETURN OF LOW LEVEL
MOISTURE WHICH WILL LIKELY DRY AFTERNOON RH INTO THE LOWER 20S
WHILE SURFACE WINDS GUST TO 30 MPH...ENHANCING THE FIRE THREAT ON
SUNDAY.

LITTLE IN THE WAY OF SENSIBLE WEATHER IS THEN EXPECTED AS THE LEAD
SHORTWAVE IS KICKED OUT OF THE WESTERN TROUGH AND THROUGH THE
NORTHERN PLAINS MONDAY.

OVERALL GFS AND ECMWF SOLUTION IS CONVERGING ON A SLOWER
SOLUTION WITH THE MEAN TROUGH...THOUGH AM LEFT WONDERING HOW MUCH LOW
LEVEL MOISTURE WILL BE AVAILABLE AHEAD OF THE EVENTUAL SURFACE
FRONT THAT IS NOW EXPECTED ON WEDNESDAY.

RUNNELS

&&

AVIATION...
/ISSUED 1150 PM CDT THU NOV 4 2010/

FOR THE 05/0600Z KSGF/KJLN/KBBG TAFS...VFR CONDITIONS ARE EXPECTED
THROUGH THE PERIOD. HIGH PRESSURE OVER THE PLAINS WILL GRADUALLY
SHIFT EAST INTO EASTERN KANSAS AND MISSOURI BY LATE FRIDAY. LOW
LEVEL WINDS WILL REMAIN FAIRLY STRONG ABOVE A FAIRLY WEAK SFC
INVERSION TONIGHT...AND WILL CONTINUE THE MENTION OF LOW LEVEL
WIND SHEAR. WE COULD SEE A BRIEF PERIOD OF GUSTY WINDS ONCE THE
INVERSION MIXES OUT AFTER 05/1400Z...BUT WINDS SHOULD DIMINISH
FROM WEST TO EAST AS THE SFC HIGH APPROACHES LATE IN THE DAY. DSA

&&

FIRE WEATHER...

THE RED FLAG WARNING HAS EXPIRED...BUT GUSTY NORTH WINDS WITH
RELATIVELY POOR HUMIDITY RECOVERY WILL OCCUR TONIGHT. COULD SEE A
PERIOD OF GUSTY NORTHWEST WINDS ONCE A WEAK INVERSION MIXES OUT
AFTER 9 AM. THE BEST CHANCES FOR STRONGER WINDS WILL BE OVER THE
EASTERN PORTION OF THE FIRE WEATHER FORECAST AREA. DEW POINTS WILL
QUITE LOW ON FRIDAY...LIKELY LOWER THAN GUIDANCE IN THE
AFTERNOON...BUT FORTUNATELY TEMPERATURES WILL BE COOLER TOO.

ALTHOUGH AFTERNOON RELATIVE HUMIDITIES WILL FALL BELOW 30 PERCENT
OVER MANY AREAS ON SATURDAY...WINDS WILL BE LIGHTER THAN THEY
WERE THURSDAY AFTERNOON. SUNDAY WILL THEN BE A DIFFERENT STORY AS
SOUTHERLY WINDS INCREASE AND BECOME GUSTY. MODELS ARE LIKELY TOO
QUICK TO BRING BACK MOISTURE IN THIS REGIME...SO CRITICAL FIRE
WEATHER CONDITIONS WILL BE A POSSIBILITY AGAIN SUNDAY AFTERNOON.

SCHAUMANN/DSA

&&

SGF WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...FREEZE WARNING FROM 3 AM TO 9 AM CDT FRIDAY FOR KSZ073-097-101.

&&

$$

Weather Information from www.artmorris.com