Tuesday, March 30, 2010

Area Forecast Discussion - South Central/Southwest Missouri

FXUS63 KSGF 301706
AFDSGF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPRINGFIELD MO
1206 PM CDT TUE MAR 30 2010

..UPDATE TO PUBLIC AND FIRE WEATHER...

UPDATE...

NUDGED UP HIGHS FOR TODAY BASED ON SHORT TERM TEMPERATURE TRENDS
AND MORNING RAOB. DESPITE FILTERED SUNSHINE FROM HIGH
CLOUDS...TEMPERATURES ARE HAVING LITTLE PROBLEM CLIMBING GIVEN THE
DRY AIRMASS. HAVE ALSO LOWERED HOURLY DEW POINT AND RELATIVE
HUMIDITY GRIDS AS AREA SOUNDINGS...KSGF...KOUN...KTOP...KSHV...ALL
INDICATE QUITE A DRY LAYER JUST OFF THE DECK. THIS WILL HAVE BIG
IMPACTS ON FIRE WEATHER. SEE DISCUSSION BELOW. FINALLY...HAVE
INCREASED WINDS ABOUT 5 MPH ACROSS MUCH OF THE AREA.

SCHAUMANN

&&

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...

SURFACE WINDS WILL INCREASE THIS MORNING ABOVE 10 KNOTS WITH
GUSTS NEAR 20 KNOTS IN RESPONSE TO A TIGHTENING PRESSURE GRADIENT
ACROSS THE REGION. LOW PRESSURE WILL FURTHER STRENGTHEN ACROSS
THE PLAINS TONIGHT WITH A LOW LEVEL JET INCREASING TO NEAR 55
KNOTS RESULTING IN THE DEVELOPMENT OF LOW LEVEL WIND SHEAR
TONIGHT INTO WEDNESDAY MORNING.

ANGLE

&&

FIRE WEATHER...

HOISTED A RED FLAG WARNING FOR THIS AFTERNOON FOR AREAS ALONG AND
WEST OF THE HIGHWAY 65 CORRIDOR. DRIER AIR IS BEGINNING TO MIX
DOWN TO THE SURFACE...RESULTING IN RELATIVE HUMIDITIES ALREADY IN
THE UPPER 20 PERCENT RANGE AT THE NOON HOUR. SUSTAINED WINDS IN
THE 15 TO 25 MPH RANGE CONTINUE...WITH GUSTS OVER 35 MPH. WILL BE
LOOKING CLOSELY AT WEDNESDAY FOR POSSIBLE EXPANSION/UPGRADE OF
CURRENT FIRE WEATHER WATCH.

SCHAUMANN

&&

SGF WATCHES/WARNINGS/ADVISORIES...
MO...RED FLAG WARNING UNTIL 7 PM CDT THIS EVENING FOR MOZ055-066>068-
077>079-088>090-093>095-101>103.

FIRE WEATHER WATCH FROM WEDNESDAY AFTERNOON THROUGH WEDNESDAY
EVENING FOR MOZ066-067-077-078-088-089-093-094.

KS...RED FLAG WARNING UNTIL 7 PM CDT THIS EVENING FOR KSZ073-097-101.

FIRE WEATHER WATCH FROM WEDNESDAY AFTERNOON THROUGH WEDNESDAY
EVENING FOR KSZ073-097-101.

&&

$$


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