Monday, October 25, 2010

Area Forecast Discussion - South Central/Southwest Missouri

FXUS63 KSGF 260014
AFDSGF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPRINGFIELD MO
714 PM CDT MON OCT 25 2010

..MESOSCALE CONVECTIVE DISCUSSION...

..UPDATE TO AVIATION...

UPDATE...
/ISSUED 710 PM CDT MON OCT 25 2010/

A COLD FRONT STRETCHED FROM NEAR OMAHA TO WICHITA EARLY THIS
EVENING WHILE A POWERFUL 150 KT UPPER JET WAS STREAKING FROM THE GREAT
BASIN INTO THE SOUTHERN ROCKIES. STRONG LOW LEVEL MOISTURE
ADVECTION CONTINUED AHEAD OF THE FRONT EARLY THIS EVENING WITH THE
HELP OF A 50 KT LOW LEVEL JET.

THE POTENTIAL FOR SEVERE WEATHER APPEARS TO BE INCREASING FOR
LATER THIS EVENING AND OVERNIGHT. GIVEN THE RAPID RETURN OF LOW
LEVEL MOISTURE CONVECTION WILL LIKELY DEVELOP A LITTLE EARLIER
AND BIT DEVELOP FARTHER WEST. BEST ESTIMATE IS FOR CONVECTION TO
DEVELOP ALONG THE FRONT AS IT PUSHES TO NEAR THE MISSOURI KANSAS
BORDER AS EARLY AS 04Z/11 PM CDT. A SQUALL LINE WILL QUICKLY TAKE
SHAPE AND SWEEP RAPIDLY EAST ACROSS THE OZARKS OVERNIGHT. THE
INTENSE WIND FIELD AND FAVORABLE SHEAR PROFILES WILL SUPPORT THE
POTENTIAL OF DAMAGING STRAIGHT LINE WINDS. A TORNADO OR TWO CANNOT
BE RULED OUT GIVEN THE STRONG 0-3 KM HELICITIES.

WHILE SURFACE WINDS REMAIN GUSTY BETWEEN 20 AND 30 KTS...WIND
SPEEDS HAVE REMAINED BELOW ADVISORY CRITERIA. THEREFORE THE WIND
ADVISORY WILL BE ALLOWED TO EXPIRE AT 8 PM.

FOSTER

&&

DISCUSSION...

AN IMPRESSIVE STORM SYSTEM WAS SHIFTING ACROSS THE NATIONS MID
SECTION THIS AFTERNOON...WITH THE SURFACE LOW CENTERED OVER NORTH
CENTRAL KANSAS AT 1930Z. A STRONG PRESSURE GRADIENT ALLOWED FOR
RAPID MOISTURE TRANSPORT BACK INTO THE OZARKS. THIS MOISTURE
ADVECTION WAS PREDOMINATELY WITHIN THE LOWEST KILOMETER OF THE
TROP. THEREFORE...THE DEPTH OF THE MOISTURE PLUME WILL REMAIN
RATHER SHALLOW THROUGH TONIGHT.

THE LATEST SHORT TERM MODEL GUIDANCE SUGGESTS THAT A LINE OF STRONG
TO POTENTIALLY SEVERE STORMS WILL DEVELOP NEAR OR MAYBE JUST EAST OF
THE HIGHWAY 71 AFTER MIDNIGHT TONIGHT. THIS SQUALL LINE WILL LIKELY
OCCUR IN RESPONSE TO THE APPROACH OF A COLD FRONT...THAT WAS LOCATED
OVER CENTRAL KANSAS THIS AFTERNOON. MASSIVE LARGE SCALE ASCENT WILL
ALSO OCCUR AS A VIGOROUS SPEED MAX DIGS ACROSS THE REGION.

WE ELECTED TO ADVERTISE A POTENTIAL FOR SEVERE WIND GUSTS ALONG WITH
AN ISOLATED TORNADO OR TWO. WIND SHEAR WILL BE OFF THE CHART
TONIGHT...AS 0-3 KM BULK SHEAR MAGNITUDES WILL RANGE FROM 45 TO 55
KNOTS. MEANWHILE...MOST SHORT TERM MODELS DISTRIBUTE CAPE WITHIN
THE LOWEST 3 KM...WHICH HAS BEEN SHOWN TO INCREASE THE TORNADO RISK
WITHIN SQUALL LINE THUNDERSTORMS OVER SOUTHERN MISSOURI. KEEP IN
MIND THOUGH...OVERALL MIXED LAYER CAPE WILL STRUGGLE TO INCREASE
BEYOND 500-700 J/KG. THIS WILL MITIGATE THE FREQUENCY OF SEVERE
STORMS TO A CERTAIN DEGREE. DUE TO THE MODEST LEVELS OF
INSTABILITY...LARGE HAIL IS NOT A LIKELY HAZARD WITH STORMS TONIGHT.

STORMS WILL EXIT THE OZARKS BY EARLY TUESDAY MORNING SETTING THE
STAGE FOR A DRY AND WINDY DAY. DESPITE THE FRONTAL PASSAGE
TONIGHT...TEMPERATURES COULD WARM RIGHT BACK INTO THE 70S OVER
SOUTHEAST KANSAS AND FAR WESTERN MISSOURI. HIGHWAY 65 TO THE EAST
WILL EXPERIENCE 60S.

THESE WARM TEMPERATURES COMBINED WITH SUSTAINED WINDS RANGING FROM
15 TO 25 MPH COULD POSE A RISK FOR CONDITIONS THAT COULD LEAD TO
WILD FIRE BEHAVIOR. ESPECIALLY FOR THE OSAGE PLAINS REGION OF
SOUTHEAST KANSAS AND WEST CENTRAL MISSOURI...PRAIRIE GRASS WILL BE
SUSCEPTIBLE TO THE RAPID SPREAD OF ANY GRASS FIRES THAT ARE IGNITED.

AS FOR THE REST OF THE WORK WEEK...MILD AND DRY WEATHER IS EXPECTED
AS A RIDGE OF HIGH PRESSURE BUILDS OVER THE NATIONS MID SECTION.
TEMPERATURES WILL RANGE FROM THE LOWER 60S TO THE UPPER 60S ON A
DAILY BASIS...WHILE OVERNIGHT LOWS COOL INTO THE UPPER 30S AND 40S.

THE NEXT CHANCES FOR PRECIP MAY OCCUR EARLY NEXT WEEK AS MEDIUM
RANGE MODELS INDICATE THE APPROACH OF ANOTHER VIGOROUS SHORT WAVE
DISTURBANCE.

CRAMER

&&

AVIATION...

FOR THE 00Z TAFS...A STRONG LOW PRESSURE CENTER OVER NORTHEASTERN
KANSAS WILL MOVE TOWARDS THE OZARKS OVERNIGHT. THE RESULTANT TIGHT
SURFACE GRADIENT WILL KEEP WINDS GUSTY OVERNIGHT IN ADVANCE OF A
COLD FRONT THAT WILL PUSH THROUGH THE AREA AROUND THE 05 TO 07Z
TIME FRAME. A STRONG LOW LEVEL JET...FOR THIS TIME OF YEAR...NEAR
70KT WILL CREATE SIGNIFICANT LOW LEVEL WINDS SHEAR AT ALL
TERMINALS THROUGH 11Z. AS THE COLD FRONT MOVES EAST...THUNDERSTORMS
ARE EXPECTED TO DEVELOP THOUGH THE COVERAGE AND SPEED OF THE
SYSTEM IS UNCERTAIN. FOR THIS REASON...USED VCTS AND VCSH FOR THE
FRONT AND WILL AMEND AS NEEDED WHEN STORM INITIATE AND MORE
CERTAINTY IS AVAILABLE. WHERE STORMS DEVELOP IN IN PROXIMITY OF
THE FRONT MVFR TO BRIEF IFR CONDITIONS MAY BE POSSIBLE.

HATCH

&&

FIRE WEATHER...

SFC TEMPS TODAY EXPECTED TO WARM INTO THE LOW 80S AT MOST
LOCATIONS...WITH SOUTH WINDS SUSTAINED BETWEEN 20 AND 25 MPH WITH
GUSTS 30 TO 35 MPH DURING THE DAY AND THIS EVENING. WHILE RH
VALUES EXPECTED TO REMAIN WELL ABOVE RED FLAG CRITERIA...WARM
TEMPS AND STRONG WINDS MAY RESULT IN FIRE CONCERNS. STRONG COLD
FRONT WILL SHIFT WINDS TO WEST THIS EVENING AND OVERNIGHT...AND
BRING WITH IT LOWER RH VALUES FOR MUCH OF THE REMAINDER OF THE
WEEK. CURRENT FORECASTS INDICATE THAT RH VALUES TUES-FRI WILL BE
IN 25-35% RANGE IN MANY PLACES...WITH WINDS 10-15 MPH. WILL REALLY
NEED TO WATCH CONDITIONS FOR TUESDAY AFTERNOON AS WESTERLY WINDS
INCREASE AND BECOME GUSTY. WOULD NOT BE SURPRISED TO SEE LOCALIZED
AREAS APPROACH CRITICAL FIRE WEATHER CONDITIONS.

BOXELL/SCHAUMANN

&&

SGF WATCHES/WARNINGS/ADVISORIES...
MO...WIND ADVISORY UNTIL 8 PM CDT THIS EVENING FOR MOZ066-077>079-
088>090-093-094-101-102.

KS...WIND ADVISORY UNTIL 8 PM CDT THIS EVENING FOR KSZ073-097-101.

&&

$$

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