Monday, September 20, 2010

Area Forecast Discussion - South Central/Southwest Missouri

FXUS63 KSGF 201727
AFDSGF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPRINGFIELD MO
1227 PM CDT MON SEP 20 2010

..UPDATE TO AVIATION...

DISCUSSION...

FAR MORE JULY THAN SEPTEMBER-LIKE PATTERN REMAINS IN PLACE OVER THE
AREA THIS MORNING...WITH EXPANSIVE MID AND UPPER LEVEL RIDGE
CENTERED OVER NORTH-CENTRAL ARKANSAS...STRETCHING FROM THE DESERT
SOUTHWEST TO THE GEORGIA COAST. THIS IS RESULTING IN BROAD
SOUTHERLY SURFACE FLOW OVER THE REGION...WITH BOTH AFTERNOON HIGHS
AND OVERNIGHT LOWS REFLECTING THE SUMMER PATTERN. LARGE UPPER LOW
EVIDENT IN WATER VAPOR IMAGERY OVER BRITISH COLUMBIA AND THE PAC
NORTHWEST IS EXPECTED TO TRAVERSE THE NORTHERN ROCKIES OVER THE
NEXT 24 HOURS OR SO...WHICH WILL ACT TO FLATTEN THE UPPER RIDGE
EVER SO SLIGHTLY OVER THE CWA. UNFORTUNATELY...EACH RUN OF MODEL
GUIDANCE PUSHES THE SHORTWAVE...AND ASSOCIATED SURFACE LOW AND
COLD FRONT...A TAD FARTHER NORTH...BRINGING INTO REAL QUESTION WHAT
EFFECT THIS SYSTEM WILL HAVE ON THE AREA. AT THIS POINT...AM ALL
BUT CONVINCED THAT CHANCES OF FROPA MID WEEK ARE NIL...AND HAVE
MAINTAINED CHANCE TO SLIGHT CHANCE MENTION OF PRECIP NORTH OF I-44
FOR TUESDAY NIGHT AND WEDNESDAY...THOUGH CONFIDENCE CERTAINLY
ISN'T HIGH EVEN IN THAT. WHAT I DO HAVE FAR MORE CONFIDENCE IN IS
THE VERY WARM TEMPERATURES...WITH BOTH HIGHS AND LOWS QUITE A BIT
ABOVE NORMAL. CLIMATE DISCUSSION BELOW LISTS OUT RECORD HIGHS AND
WARM LOWS...AND WOULDN'T BE SURPRISED TO SEE A FEW OF THOSE RECORD
WARM LOWS FALL BY MID TO LATE WEEK.

BY WEDNESDAY NIGHT...MUCH STRONGER AND MORE DEVELOPED SHORTWAVE IS
EXPECTED TO MOVE ONSHORE ALONG THE PACIFIC COAST...AND EJECT OUT
OVER THE HIGH PLAINS BY THURSDAY MORNING. THIS IS EXPECTED TO
RESULT IN VERY DEEP AND RAPID LEE CYCLOGENESIS JUST EAST OF THE
FRONT RANGE. GUIDANCE AT THIS POINT HAS THE SURFACE LOW LIFTING
NORTHEAST FROM NORTHERN COLORADO TO SOUTHERN MINNESOTA DURING THE
DAY THURSDAY...WHICH WOULD PLACE THE SGF CWA...ESPECIALLY WESTERN
SECTIONS...IN LINE FOR VERY GUSTY SOUTHERLY FLOW DURING THE DAY.
EXACT MAGNITUDE OF WIND SPEED WILL BE HIGHLY DEPENDENT ON EVENTUAL
SURFACE LOW TRACK...BUT WOULD APPEAR THAT PORTIONS OF THE AREA
HITTING WIND ADVISORY CRITERIA CAN'T BE RULED OUT.

STRONG COLD FRONT APPROACHES THE AREA THURSDAY AFTERNOON AND
EVENING...WITH SHOWERS AND THUNDERSTORMS AHEAD OF IT. SEVERE
WEATHER POTENTIAL WITH THIS FRONT IS QUESTIONABLE...WITH BETTER
UPPER LEVEL ENERGY WELL NORTH OF THE CWA.
NONETHELESS...CONSIDERING THE ENERGETIC PARENT SURFACE LOW AND
EXPECTED SHARP FRONTAL BOUNDARY...DEGREE OF FORCING MAY BE ENOUGH
TO RESULT IN SOME SCATTERED STRONG TO SEVERE CONVECTION. NOT
UNLIKE THE SYNOPTIC WIND THREAT DURING THE DAY THURSDAY...THIS IS
SOMETHING THAT WILL NEED TO BE FINE TUNED AS EXACT SYSTEM TRACK
AND MESOSCALE DETAILS BECOME MORE APPARENT.

NO CHANGES MADE BEYOND FRIDAY...WITH MODEL GUIDANCE DIVERGING
SIGNIFICANTLY BY THE WEEKEND. AT THE VERY LEAST...CERTAINLY WOULD
APPEAR THAT MORE SEASONABLE TEMPERATURES AND HUMIDLY LEVELS WILL
RETURN FOR AT LEAST A TIME OVER THE NEXT WEEKEND IN ONE FORM OR
ANOTHER.

BOXELL

&&

AVIATION...

VFR CONDITIONS WILL CONTINUE THROUGH TUESDAY MORNING. SOUTHERLY
WINDS WILL INCREASE TO AT LEAST 12 KNOTS BY LATE TUESDAY MORNING.

SCHAUMANN

&&

CLIMATE...

UNSEASONABLY WARM AND HUMID AIR IS EXPECTED TO REMAIN IN PLACE
THROUGH MUCH OF THE COMING WEEK AS A LARGE UPPER LEVEL RIDGE OF
HIGH PRESSURE ANCHORS ITSELF OVER THE SOUTHERN HALF OR SO OF THE
UNITED STATES. AT THIS POINT...IT WOULD APPEAR THAT MOST RECORD
HIGH TEMPERATURE RECORDS ARE SAFE...BUT A FEW RECORD WARM LOW
TEMPERATURE RECORDS ARE IN JEOPARDY. HERE ARE THE RECORD HIGHS
AND RECORD WARM LOWS FOR THE COMING WORKWEEK FOR
SPRINGFIELD...JOPLIN...VICHY/ROLLA...AND WEST PLAINS.

DATE...REC HIGH (YEAR)/REC WARM LOW (YEAR)....

SPRINGFIELD...

9/20...97 (1954) / 71 (1931)
9/21...93 (1955) / 73 (1931)
9/22...93 (1937) / 69 (1935)
9/23...92 (1960) / 72 (1921)
9/24...92 (1939) / 74 (1984)

JOPLIN...

9/20...99 (1954) / 75 (1980)
9/21...95 (1956) / 76 (1980)
9/22...95 (1956) / 73 (1988)
9/23...89 (2005) / 73 (1986)
9/24...89 (1984) / 76 (1958)

VICHY/ROLLA...

9/20...95 (1954) / 71 (1948)
9/21...94 (1955) / 72 (1970)
9/22...95 (1956) / 69 (1993)
9/23...92 (1897) / 68 (2005)
9/24...93 (1901) / 69 (1958)

WEST PLAINS...

9/20...97 (1955) / 69 (1948)
9/21...95 (1955) / 69 (1964)
9/22...92 (1948) / 68 (1970)
9/23...94 (2005) / 69 (1984)
9/24...90 (1961) / 72 (1984)

BOXELL

&&

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

$$


Weather Information from www.artmorris.com