FXUS63 KDMX 271135
AFDDMX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
535 AM CST FRI NOV 27 2009
.SHORT TERM /TODAY/...
LITTLE OF CONCERN THROUGH TODAY. AIRMASS QUITE DRY WITH WARM
ADVECTION CONTINUING TO INCREASE AS SFC RIDGE PROGRESSES GRADUALLY
EASTWARD. WINDS WILL STILL BE FAIRLY LIGHT...BUT IT MAY STILL MIX A
TAD MORE THAN BUFR SOUNDINGS SUGGEST DUE TO FULL SUN AND DRY AIRMASS
SO SEE NO REASON TO DEVIATE FROM GUIDANCE MUCH. 25-30 DEGREE
DIURNAL SWING OCCURRED UPSTREAM YESTERDAY AND EXPECT SIMILAR
CONDITIONS TODAY...ESPECIALLY WEST.
.LONG TERM /TONIGHT THROUGH TUESDAY/...
THE EXTENDED PERIOD WILL BE RATHER UNEVENTFUL. MODEL CONSENSUS
REMAINS WITH THE SOLUTION OF A BROAD UPPER LEVEL LONG WAVE TROUGH
SPLITTING AS THE SOUTHERN PORTION DEVELOPS INTO A CLOSED LOW. THE
FEATURE NEVER REALLY TAPS INTO DECENT MOISTURE UNTIL IT GETS EAST OF
THE CWA AND WITH THE NORTHERN STREAM WAVE THE DYNAMICS STAY TO THE
NORTH OF THE CWA. THUS WE WILL SEE AN INCREASE IN CLOUD COVER
SUNDAY AS THE FEATURE MOVES ACROSS. TEMPERATURES WILL ALSO BE
COOLER SUNDAY AND MONDAY. A WEAK UPPER LEVEL RIDGE WILL PUSH ACROSS
THE FORECAST AREA MONDAY NIGHT AND TUESDAY FOR A BRIEF PERIOD OF
WARMING.
THE NEXT NOTABLE WEATHER IS WELL OUTSIDE OF THIS FORECAST PACKAGE
BUT MODELS ARE INDICATING A BIG COOL DOWN LATE NEXT WEEK AND ALSO
BECOMING A LITTLE MORE ACTIVE ONCE AGAIN. A LARGE TROUGH IS
FORECAST TO DEVELOP OVER THE AREA BEGINNING WEDNESDAY AND A WEAK
COLD FRONTAL PASSAGE WILL BRING IN THE FIRST SHOT OF COLD AIR. SOME
MODEL DIFFERENCES AT THIS POINT BUT BY THE END OF NEXT WEEK 850
TEMPS GO WELL BELOW ZERO...IN THE -10 TO -15 RANGE. THIS WOULD
SPELL HIGHS IN THE 30S...OR LOWER. THE DAY SHIFT WILL LOOK MORE
INTO THIS PERIOD LATER TODAY.
&&
.AVIATION...
27/12Z...VFR CONDITIONS WITH NOTHING MORE THAN PATCHY CIRRUS
EXPECTED THROUGH 06Z. THERE ARE SOME INDICATIONS THAT GROUND FOG
MAY DEVELOP EARLY SAT MORNING...SO HAVE ADDED MVFR VSBYS AT MCW/ALO
WHICH MAY NOT SEE AS MUCH MIXING TODAY.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM/AVIATION...BSS
LONG TERM...FAB
