FXUS63 KDMX 142341 AAA
AFDDMX

AREA FORECAST DISCUSSION...CORRECTED UPDATE
NATIONAL WEATHER SERVICE DES MOINES IA
538 PM CST MON DEC 14 2009

...CORRECTED AVIATION DISCUSSION...

.SHORT TERM /TONIGHT/...
SCATTERED FLURRIES WILL END EARLY THIS EVENING AS SUBSIDENCE 
INCREASES AND CLEARING SPREADS ACRS THE CWA.  ARCTIC AIR MASS WILL 
CONTINUE TO SLIDE INTO THE STATE ON NORTHWEST WINDS OVERNIGHT AS 
TEMPERATURES DROP BELOW ZERO ACRS THE STATE.  WIND CHILLS DURING THE 
NIGHT ARE EXPECTED TO DROP TO BETWEEN 15 AND 25 BELOW ZERO WITH THE 
NORTHERN HALF OF THE AREA...MAINLY ALONG AND NORTH OF HIGHWAY 30 
EXPERIENCING WIND CHILL ADV CRITERIA AND HAVE OPTED TO ISSUE AN 
ADVISORY FROM 06Z-16Z ON TUESDAY FOR THIS THREAT.

.LONG TERM /TUESDAY THROUGH MONDAY/...NO MAJOR FORECAST CONCERNS 
DURING THE EXTENDED. COLD SNAP STILL ON TRACK TOMORROW INTO
WEDNESDAY WITH HIGH PRESSURE DOMINATING OVER THE REGION. A SERIES
OF SHORTWAVES AFFECT THE REGION FRIDAY INTO SATURDAY...WITH
ANOTHER SYSTEM THROUGH LATE SUNDAY INTO MONDAY.

TUESDAY INTO THURSDAY...HIGH PRESSURE WILL DOMINATE THE REGION 
DURING THE TIME FRAME AND LOOKS TO BE CENTERED OVER THE CWA BY 00Z 
WED. VERY DRY AND COLD AIR MASS PERSISTS INTO WEDNESDAY...SO
DECREASED CLOUD COVER TOMORROW INTO WEDNESDAY. HIGH PRESSURE 
BEGINS TO SHIFT EAST OVERNIGHT TUESDAY NIGHT INTO
WEDNESDAY...ALLOWING FOR WEAK WAA TO DEVELOP ACROSS THE CWA. HAVE
A NON-DIURNAL TEMP TREND WITH LOWS AT 06Z WED AND THEN TEMPS
SLOWLY RISING TOWARDS THE MORNING HOURS WEDNESDAY. BUFR SOUNDINGS
SHOWING VERY SHALLOW LAYER OF COLD AIR OVERNIGHT TUESDAY ERODING
AWAY WEDNESDAY MORNING. CLOUDS ON THE INCREASE WEDNESDAY NIGHT AND
ON THURSDAY WITH SOME THETA-E ADVECTION ALOFT ASSOCIATED WITH A
WEAK SHORTWAVE.

FRIDAY THROUGH MONDAY...STILL SOME DISCREPANCIES WITH THE EXTENDED 
MODELS BUT THE GFS/ECMWF ARE SHOWING SIGNS OF COMING INTO BETTER 
AGREEMENT WITH A SHORTWAVE THROUGH ON FRIDAY. TIMING LOOKS TO BE
DECENT BUT ECMWF HAS UPPER LOW CUTTING ACROSS THE PLAINS WHILE THE
GFS KEEPS THE SYSTEM OVER THE MIDWEST REGION FRIDAY INTO SATURDAY.
KEPT SMALL POPS IN FRIDAY THROUGH SATURDAY. STRONG UPPER LOW
DEVELOPS AND HOLDS IN A PLACE ACROSS THE GREAT LAKES AND PUTS THE
CWA IN CAA REGIME SUNDAY INTO MONDAY. AS A RESULT...INSERTED SMALL
POPS FOR SNOW SUNDAY AFTERNOON AND INCREASED WINDS WITH PRESSURE
GRADIENT TIGHTENING.

&&

.AVIATION...
15/00Z...ARCTIC HIGH PUSHING INTO THE STATE NOW AND THAT IS PUSHING 
THE MVFR/IFR CIGS TO THE SE. FLURRIES STILL POSSIBLE SE OF A LINE 
FROM KMIW TO KCSQ THROUGH 06Z.  EXPECT CLEARING FM WNW TO SSE 
THROUGH 09Z.  PRESSURE GRADIENT STILL TIGHT ACROSS THE CWA SO WINDS 
WILL BE AN ISSUE TONIGHT THOUGH THEY WILL GRADUALLY DIMINISH THROUGH 
12Z.  AFT 12Z VFR CONDITIONS AND LIGHT WIND JUST VERY COLD.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...WIND CHILL ADVISORY NORTHERN HALF 
OF FORECAST AREA 06Z-16Z.

&&

$$

SHORT TERM...COGIL
LONG TERM...PODRAZIK
AVIATION...FAB