Friday, April 30, 2010

Area Forecast Discussion - South Central/Southwest Missouri

FXUS63 KSGF 301150
AFDSGF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPRINGFIELD MO
650 AM CDT FRI APR 30 2010

..UPDATE TO AVIATION...

DISCUSSION...

FORECAST HIGHLIGHTS INCLUDE WINDY CONDITIONS IN THE NEAR TERM
FOLLOWED BY CHANCES FOR STRONG TO SEVERE THUNDERSTORMS FRIDAY
AFTERNOON INTO FRIDAY EVENING. ADDITIONAL THUNDERSTORMS WILL BE
POSSIBLE SATURDAY WITH THE POTENTIAL OF STRONG TO SEVERE
THUNDERSTORMS IN SOUTH CENTRAL MISSOURI.

ALONG A COLD FRONT IN THE PLAINS...A BROKEN LINE OF STRONG TO
SEVERE THUNDERSTORMS HAS TRACKED EAST THROUGH KANSAS OVERNIGHT.
AHEAD OF THIS FRONT...THE LOW LEVEL JET HAS INCREASED TO 70 TO 80
KNOTS. MIXING WILL ALLOW SURFACE WINDS ACROSS SOUTHEAST KANSAS
AND PORTIONS OF SOUTHWEST MISSOURI TO REACH GUSTS NEAR 40 MPH
THROUGH MID MORNING. A STRATUS DECK ASSOCIATED WITH LOW LEVEL
MOISTURE TRANSPORT FROM THIS LOW LEVEL JET WILL ADVECT NORTH INTO
THE OZARKS BY MID MORNING. THUNDERSTORMS IN KANSAS TRACKING EAST
ARE ANTICIPATED TO CONTINUE TO WEAKEN EARLY THIS MORNING AS A
RESULT OF AN OUTFLOW BOUNDARY MIGRATING AHEAD OF THE
FRONT...LOWER INSTABILITY AND A STRONGER CAPPING INVERSION ACROSS
THE OZARKS. THIS AFTERNOON AND INTO THIS EVENING...THE FRONT WILL
MOVE EAST THROUGH PORTIONS OF THE OZARKS. ALONG THIS
FRONT...STRONG TO SEVERE THUNDERSTORMS WILL BE POSSIBLE WITH
FORECAST MODELS PROGGING 0-6KM BULK WIND SHEAR RANGING FROM 60-80
KNOTS...0-1KM HELICITY RANGING FROM 100-200 M2/S2 AND 0-1KM CAPE
NEAR 1000 J/KG. WHILE ALL MODES OF SEVERE WEATHER WILL BE
POSSIBLE...DAMAGING WINDS AND LARGE HAIL ARE THE EXPECTED PRIMARY
THREATS WITH A SECONDARY TORNADO THREAT MOST FAVORABLE IN BROKEN
LINE SEGMENTS AND IF ANY SUPERCELLS CAN DEVELOP AHEAD OF THE
EASTWARD ADVANCING FRONT.

THE FORECAST INTO THE WEEKEND BECOMES CONDITIONAL ON THE
EVOLUTION OF CONVECTION TONIGHT WITH MODEL SOLUTIONS DIVERGING ON
THE EASTWARD PROGRESSION OF THIS FRONT. SHOWERS AND THUNDERSTORMS
WILL BE LIKELY TONIGHT WITH THE LOW LEVEL JET AND MOISTURE
TRANSPORT INTERACTING WITH THE FRONTAL BOUNDARY PRODUCING
MODERATE TO HEAVY RAIN ALONG WITH THE POTENTIAL OF LOCALIZED
FLOODING WHERE THUNDERSTORMS TRAIN AND FROM HIGH RAINFALL RATES.
THE SURFACE BOUNDARY IS EXPECTED TO LIFT BACK NORTH THROUGH THE
OZARKS OVER THE WEEKEND BRINGING ADDITIONAL CHANCES FOR SHOWERS
AND THUNDERSTORMS. THERE IS A CONDITIONAL RISK FOR ADDITIONAL
STRONG TO SEVERE THUNDERSTORMS SATURDAY IN SOUTH CENTRAL MISSOURI
DEPENDENT UPON INSTABILITY ALONG WITH THE DEVELOPMENT OF A
SURFACE LOW.

ANGLE

&&

AVIATION...

FOR THE 12Z TAF PACKAGE...FORECAST CHALLENGES INCLUDE GUSTY
SOUTHERLY WINDS TODAY...POTENTIAL FOR MVFR CIGS AND THUNDERSTORM
CHANCES. A COLD FRONT IS CURRENTLY OVER EASTERN KANSAS. THIS IS
WHERE TSRA HAVE BEEN MOST FREQUENT SO FAR THIS MORNING. LITTLE
EASTWARD PROGRESS WILL BE MADE UNTIL THIS AFTERNOON WHEN THE FRONT
EDGES TO THE EAST. THIS MORNING STRATUS WILL CONTINUE TO SPREAD
NORTHWARD...FLIRTING WITH MVFR FOR A TIME...OTHERWISE CIGS SHOULD
STAY JUST INTO THE VFR RANGE. OTHER RESTRICTIONS WILL BE POSSIBLE
AS TSRA AFFECT THE AERODROMES LATER THIS AFTERNOON AND EVENING
WHERE MVFR CIG/VIS WILL BE POSSIBLE. CLEARING IS EXPECTED FROM
WEST TO EAST DURING THE MID TO LATE EVENING.

GAGAN

&&

SGF WATCHES/WARNINGS/ADVISORIES...
MO...WIND ADVISORY UNTIL 10 AM CDT THIS MORNING FOR MOZ055-066>068-
077>079-088>090-093>095-101>103.

KS...WIND ADVISORY UNTIL 10 AM CDT THIS MORNING FOR KSZ073-097-101.

&&

$$


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