Tuesday, March 30, 2010

Area Forecast Discussion - South Central/Southwest Missouri

FXUS63 KSGF 300832
NATIONAL WEATHER SERVICE SPRINGFIELD MO
332 AM CDT TUE MAR 30 2010

DISCUSSION...

FORECAST CHALLENGES THIS PACKAGE INCLUDE ELEVATED FIRE WEATHER
DANGER WEDNESDAY AND THURSDAY AND RAIN CHANCES FOR LATE FRIDAY AND
SATURDAY.

CURRENTLY...RIDGE OF HIGH PRESSURE AT THE SFC IS SHIFTING EASTWARD
AND OUT OF THE AREA. PRESSURE GRADIENT ACROSS THE PLAINS IS
TIGHTENING WITH LOW PRESSURE DEVELOPING IN THE LEE OF THE NORTHERN
ROCKIES. THE SKY HAS BEEN CLEAR ACROSS THE AREA...WITH A LITTLE
CIRRUS ATTEMPTING TO MOVE IN FROM THE WEST. TEMPERATURES ACROSS
THE AREA VARY A BIT...WITH SHELTERED AREAS DIPPING INTO THE
MID/UPPER 30S AND AREAS RECEIVING WINDS IN THE MID/UPPER 40S.

SHORT TERM (TODAY THROUGH THURSDAY)...SPLENDID WEATHER IS ON TAP
FOR THE REGION AS WE WILL FINALLY ENJOY MORE THAN TWO DAYS OF
SPRING LIKE TEMPS IN SUCCESSION. UPPER RIDGING WILL HAVE FIRM
CONTROL OF OUR WEATHER REGIME WITH SOUTHERLY WINDS BECOMING
INCREASINGLY GUSTY. THE BREEZIEST DAYS LOOK TO BE WED/THU. 925/850
MB TEMPS WILL WARM TO WELL ABOVE AVERAGE AND THIS CORRELATES TO
HIGHS WELL INTO THE 70S TODAY...WITH 80S POSSIBLE NORTHWEST OF THE
PLATEAU WED/THUR. BOUNDARY LAYER DEWPOINTS WILL REMAIN AROUND THE
LOWER 40S FOR MUCH OF THIS PERIOD LEADING TO FIRE WEATHER CONCERNS
WHICH ARE DISCUSSED FURTHER IN THE FIRE WEATHER SECTION BELOW.
BOTTOM LINE IS BREEZY AND WARM FOR THE SHORT TERM WITH
TEMPERATURES WELL ABOVE AVERAGE.

LONG TERM (THURSDAY NIGHT THROUGH MONDAY)...00Z SUITE OF MODEL
OUTPUT CONVERGING ON A SIMILAR SOLUTION FOR THE FRIDAY/SATURDAY
TIME FRAME. A DISTURBANCE WILL MOVE EASTWARD OUT OF THE DESERT
SOUTHWEST AND INTO THE PLAINS BY FRIDAY NIGHT. THIS FEATURE WILL
TAKE ON A NEGATIVE TILT AND LIFT NORTHEAST FRIDAY NIGHT INTO
SATURDAY. CONVECTION IS EXPECTED TO FIRE WEST OF THE AREA FRIDAY
AFTERNOON ALONG THE SFC FRONT. BOUNDARY LAYER MOISTURE RETURN
WILL BE SUFFICIENT ENOUGH (MID 50S) TO AID IN SUSTAINING DEEP
CONVECTION ACROSS THE REGION GIVEN LIFT ASSOCIATED WITH THE FRONT
AND DECENT 500MB HEIGHT FALLS. AT THIS TIME...CONVECTIVE MODE
LOOKS TO BE LINEAR IN NATURE. DECENT SPEED SHEAR IS EXPECTED WITH
THIS SYSTEM...THOUGH DIRECTIONAL SHEAR WILL BE LACKING.
INSTABILITY WILL BE ON THE MEAGER SIDE GIVEN NIGHTTIME TIMING...
WITH MLCAPE ON THE ORDER OF 500 J/KG...GIVE OR TAKE. WILL NEED TO
KEEP AN EYE ON THE POTENTIAL FOR WIND WITH THIS SYSTEM.

THE SYSTEM THAT WILL AFFECT THE REGION FRIDAY NIGHT AND SATURDAY
LOOKS TO BE PROGRESSIVE AND WE SHOULD SALVAGE THE LATTER HALF OF
THE WEEKEND. AT THIS POINT SUNDAY SHOULD FEATURE SUNSHINE AND
TEMPERATURES WELL INTO THE 60S.

GAGAN

&&

AVIATION...

VFR CONDITIONS WILL PREVAIL THROUGH TUESDAY. SURFACE WINDS WILL BE
ON THE INCREASE AS SURFACE HIGH PRESSURE MOVES OFF TO THE EAST AND
LOW PRESSURE DEVELOPS ACROSS THE PLAINS. WIND GUSTS WILL EXCEED 20
KTS DURING THE DAY TUESDAY. LOW LEVEL WIND SHEAR WILL IMPACT THE
JOPLIN TERMINAL TONIGHT AND ALL AREA TERMINALS TUESDAY NIGHT AS
THE LOW LEVEL JET STRENGTHENS.

FOSTER

&&

FIRE WEATHER...

TODAY...SOUTHERLY WINDS WILL CONTINUE TO INCREASE...PARTICULARLY
IN AREAS ALONG/NORTHWEST OF THE OZARK PLATEAU. MODEL OUTPUT
CONTINUES TO OVERDO DEWPOINT VALUES AND HAVE UNDERCUT GUIDANCE BY
SEVERAL DEGREES IN SOME CASES. AS PREV FORECASTER INDICATED...
RED FLAG CONDITIONS FOR TODAY ARE MARGINAL AND LOOK TO ONLY BE MET
FOR AN HOUR OR TWO THIS AFTERNOON. GIVEN A VERY MARGINAL SITUATION
WILL CONTINUE TO HOLD OFF FROM ANY HEADLINES.

WEDNESDAY...HOWEVER IS SHAPING UP TO BE A DIFFERENT STORY.
FORECAST 20 FT WINDS REMAIN IN THE 15 TO 20 KT RANGE AND MINIMUM
RELATIVE HUMIDITY VALUES ARE EXPECTED TO DROP TO AROUND 25 PERCENT
DURING THE AFTERNOON HOURS. FUEL MOISTURE DRIED OUT QUITE A BIT
YESTERDAY...WITH LITTLE RECOVERY SEEN SO FAR THIS MORNING. GIVEN
WARM/BREEZY CONDITIONS...THESE VALUES SHOULD LOWER EVEN FURTHER
TODAY. THE PRIMARY CONCERN WILL CONTINUE TO BE WITH PRAIRIE GRASSES
IN THE OSAGE PLAINS. INTERAGENCY COORDINATION WILL TAKE PLACE
TODAY TO ADDRESS THE STATE OF THE ENTIRE OUTLOOK AREA. WILL ALLOW
THIS INTERAGENCY COORDINATION TO DICTATE THE PLACEMENT OF ANY FIRE
WEATHER HEADLINES...BUT WILL KICK UP WORDING IN THE FWF AND HWO
PRODUCTS. EXPECTATIONS CONTINUE TO BE THAT A RED FLAG WATCH OR
WARNING WILL LIKELY BE NECESSARY FOR AT LEAST A PORTION OF THE
OUTLOOK AREA FOR WEDNESDAY.

SCHAUMANN

&&

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

$$

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