National Weather Service Raw Text Product

Displaying AFOS PIL: AFDDMX Received: 2011-12-15 17:26 UTC


844 
FXUS63 KDMX 151726 AAB
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
1126 AM CST THU DEC 15 2011

...UPDATED AVIATION DISCUSSION... 

.SHORT TERM /TODAY/...
MAIN FORECAST CONCERN TODAY WAS WITH STRATUS DECK REMAINING ACROSS 
CENTRAL IOWA THROUGH MUCH OF THE DAY.  CURRENT SATELLITE TRENDS 
SHOWS LOW STRATUS DECK EXTENDING INTO THE DAKOTAS AND SOUTHERN 
CANADA...AND PROJECTED OVER CENTRAL AND WESTERN IOWA.  NAM/RUC WERE 
THE BEST WITH HANDLING TIMING OF STRATUS DECK DEPARTING BY MID 
AFTERNOON WITH THE GFS AROUND MIDDAY. LEANED TOWARD THE NAM/RUC 
SOLUTIONS AND BUMPED SKY COVER UP THROUGH 21Z. BUT WOULD NOT BE 
SURPRISED IF STRATUS DECK HOLDS IN PLACE THROUGH 00Z.  THINKING SOME 
MIXING MAY HELP DISSIPATE AND THIN OUT THE CLOUD DECK...BUT WITH THE 
STRONG CAA AND 925MB AOA 80 PERCENT THROUGH THIS AFTERNOON...FELT 
CONFIDENT ENOUGH TO LEAVE CLOUDS ACROSS MUCH OF THE FORECAST AREA 
TODAY. WINDS WILL REMAIN BELOW ADVISORY CRITERIA...ESPECIALLY SINCE 
THE STRATUS DECK HOLDING TIGHT THROUGH THE AFTERNOON TO KEEP BACK 
THE DEEP MIXING. WITH MAINLY THE PRESSURE GRADIENT TODAY...HAVE A 
FEW GUSTS TO 30 KNOTS IN NORTHERN IOWA THIS AFTERNOON. 
OTHERWISE...GENERALLY AROUND 20-25KTS THROUGHOUT THE FORECAST AREA.

.LONG TERM /TONIGHT THROUGH WEDNESDAY/...
CONCERNS IN THIS PERIOD ARE TEMPS INITIALLY...THE EVOLUTION OF THE 
SYSTEM EARLY NEXT WEEK...AND THE WEAK SYSTEM LATE FRIDAY TO A LESSER 
EXTENT.  EXPECT THE STRATUS TO BE GONE BY TONIGHT WITH SURFACE RIDGE 
SETTLING INTO MO VALLEY.  EXAMINATION OF BUFR SOUNDINGS SUGGESTS 
GUIDANCE TEMPS MAY BE TOO COOL TONIGHT...ESPECIALLY IN THE 
NORTH...POSSIBLY TOO INFLUENCED BY CLIMO SNOW COVER SO HAVE GONE AT 
OR JUST ABOVE WARMEST MOS.  NRN STREAM REFLECTION OF POTENT OR/NRN 
CA SHORT WAVE PASSES THROUGH CANADIAN PROVINCES TODAY AND TONIGHT 
REACHING NRN PLAINS FRI.  GFS FORCING AND MOISTURE REMAINS MOST 
AGGRESSIVE...BUT EVEN THAT HAS A NEAR SURFACE DRY LAYER WHICH MAY 
DIMINISH POTENTIAL.  HAVE CONTINUED SLIGHT CHANCES NE AND ADDED A 
BUFFER OF FLURRIES FOR THIS BRIEF PRECIP WINDOW.

DRY NW FLOW FOR THE WEEKEND WITH ATTENTION TURNING TO NEXT SWRN 
CUTOFF LOW EJECTING.  GFS HAS HAD BETTER RUN TO RUN CONTINUITY WITH 
THE SYSTEM...AND 00Z ECMWF HAS NOW TRENDED IN THAT DIRECTION WHICH 
EMPHASIZES SLOWER MORE SLY SOLUTION.  HAVE REDUCED POPS SOMEWHAT SUN 
NIGHT AND MON...BUT AM HESITANT TO MAKE ADDITIONAL CHANGES UNTIL 
FASTER/MORE NLY GEM/UKMET SOLUTIONS TREND AND ECMWF HAS AT LEAST TWO 
RUNS THAT ARE NOT FLIP FLOPPING.  IF CURRENT 00Z ECMWF/GFS SOLUTIONS 
MAINTAIN...AFTERNOON PACKAGE MAY NEED TO PLACE FURTHER EMPHASIS ON 
SLOWER/DRIER SOLUTION.

&&

.AVIATION...15/18Z
STRATUS DECK REMAINS ACROSS IOWA AT BEGINNING OF PERIOD...AND HAS 
LIFTED TO MAINLY LOW VFR...WITH A FEW POCKETS OF HIGH MVFR CEILINGS. 
PRIMARILY WILL SEE LOW VFR CEILINGS THROUGH 00Z...BEFORE HIGH 
PRESSURE PUSHES IN...CLEARING OUT CEILINGS. WINDS WILL BE FROM THE 
NORTHWEST...AND WILL BE STRONG WITH GUSTS UP TO 30KTS AT SITES IN 
THE NORTH. WINDS WILL DIMINISH NEAR 00Z AND SUNSET.

&&

.DMX WATCHES/WARNINGS/ADVISORIES...NONE.

&&


$$

SHORT TERM...PODRAZIK
LONG TERM...SMALL
AVIATION...AWB