000
FXUS63 KEAX 121713
AFDEAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO
1213 PM CDT THU MAR 12 2009

...UPDATED AVIATION DISCUSSION...

.DISCUSSION...
/410 AM CDT THU MAR 12 2009/

CWA IS KINDA IN NO MANS LAND WITH NORTHERN UPPER JET REMAINING OVER
THE GREAT LAKES WHILE SEVERAL FEATURES CAUGHT IN THE SOUTHERN STREAM
PASS JUST SOUTH OF THE CWA OVER THE NEXT COUPLE OF DAYS. WHAT THIS
SPELLS IS SEVERAL PERIODS WITH CONSIDERABLE HIGH LEVEL CLOUDS
PASSING THROUGH WHILE THE BOUNDARY LAYER TEMPERATURES GRADUALLY
MODIFY.

COLD CANADIAN HIGH PRESSURE ANCHORED OVER MN WILL SLIDE SLOWLY EAST
TODAY AND TONIGHT. ALTHOUGH THE COLD AIR ADVECTION HAS CEASED THERE
WILL BE A STEADY STREAM OF HIGH AND EVEN SOME MID CLOUDS PASSING
THROUGH THE CWA. GIVEN TEMPERATURES YESTERDAY ENDED UP COLDER THAN
GUIDANCE HAVE RESERVATIONS WE WILL REACH EVEN THE COLDER MET MOS
NUMBERS. A PRONOUNCED EASTERLY FETCH IN THE BOUNDARY LAYER IS NOT A
WARMING WIND AS IT PULLS MODIFIED COLD AIR OUT OF THE MN HIGH PLUS
THE EXTENSIVE HIGH LEVEL CLOUDINESS WILL RETARD THE DIURNAL HEAT
CYCLE. SO WILL UNDERCUT GUIDANCE MAX TEMPERATURES.

CLOUD COVER EXPECTED TO INCREASE OVERNIGHT AND FRIDAY...MAINLY OVER
THE WESTERN CWA WHERE ISENTROPIC LIFT WILL ALLOW MID CLOUDS TO FORM
OVER KS AND CURL INTO THE REGION. SHOULD SEE TEMPERATURES CONTINUE
THEIR GRADUAL WARMUP. HAVE CONSIDERABLE DOUBT WE WILL REACH THE MUCH
WARMER MAV MAX TEMPERATURES AS 850MB TEMPERATURES SHOW ONLY A SLIGHT
WARMING. IT WILL LIKELY COME DOWN TO HOW MUCH SUN WE WILL SEE AND
CURRENTLY IT LOOKS LIKE A STEADY STREAM OF MID AND HIGH CLOUDS WILL
GUNK UP THE WORKS.

THE WEEKEND LOOKS LIKE A CONTINUATION OF THE SLOW WARMING PROCESS
WITH THE NEXT CHANCE FOR MEASURABLE PRECIPITATION HOLDING OFF UNTIL
MONDAY. THE 00Z ECMWF AND GFS ARE ON THE SAME PAGE IN BRINGING A
WEAK INVERTED SURFACE TROUGH THROUGH MO DURING THE DAY. AN
ASSOCIATED SHORTWAVE LOOKS LIKE IT WILL PROVIDE SUFFICIENT LIFT TO
SUPPORT CHANCE POPS DURING THE DAY.

19

&&

.AVIATION...

VFR CONDITIONS EXPECTED THROUGH THE TAF PERIOD. MID AND HIGH LEVEL
CLOUDINESS LOOKS TO CONTINUE TO AFFECT THE TERMINALS THROUGH TONIGHT
AS SHORT WAVE TROUGH EJECTS ACROSS THE OZARKS WITH SECONDARY WAVE
PUSHING INTO THE FOUR CORNERS REGION. SFC HIGH PRESSURE WILL SHIFT
INTO THE GREAT LAKES TONIGHT KEEPING EASTERLY SFC FLOW ACROSS THE TAF
SITES.

DEROCHE

&&

.EAX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
$$