000
FXUS63 KDMX 061728
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
1128 AM CST FRI DEC 6 2013

.SHORT TERM /TODAY/...
ISSUED AT 347 AM CST FRI DEC 6 2013

PRIMARY CONCERN TODAY WILL BE TEMP AND WIND CHILL TRENDS.  STRONG
CENTRAL PLAINS TO GREAT LAKES JET...08Z RAP MAX WIND OBJECTIVELY
ANALYZED AT 180KTS OVER SRN WI...IS IN PLACE BUT MUCH OF THE
ASSOCIATED FORCING AND RESULTANT SENSIBLE WEATHER IS WELL TO OUR
SOUTH.  A FEW WEAK SHORT WAVES WITH MID LEVEL KINEMATIC FORCING ARE
RIDING THE JET BUT WITH LIMITED MOISTURE ARE PRODUCING NOTHING MORE
THAN MID CLOUDS AND LIGHT SNOW ALOFT SO FORECAST REMAINS DRY.

RECENT RAP/NAM RUNS SEEM TO HAVE A BETTER HANDLE ON THIS ARCTIC
AIRMASS THAN THE GFS...AND ARE ALSO SUPPORTED BY HI RES NMM AND
HOPWRF RUNS.  THIS THINKING WOULD SUGGEST HIGHS ONLY MAKING THE MID
SINGLE DIGITS NW TO MID TEENS SE TODAY.  WINDS WILL CHANGE LITTLE
TODAY...REMAINING STEADY FROM THE NW AROUND 10KTS PLUS...KEEPING
WIND CHILLS AT OR BELOW ADVISORY CRITERIA /-20F/ THROUGH MUCH OF THE
MORNING. NO CHANGES TO EXISTING HEADLINE.

.LONG TERM /TONIGHT THROUGH THURSDAY/...
ISSUED AT 347 AM CST FRI DEC 6 2013

TONIGHT THROUGH SATURDAY WILL BE RELATIVELY QUIET WITH RESPECT TO
PRECIPITATION BUT IT WILL BE VERY COLD. THE ARCTIC HIGH WILL PUSH
SOUTH AND EAST ACROSS THE AREA THROUGH THIS TIME. THE GRADIENT
WILL RELAX ACROSS IOWA SO THE WIND WILL DIMINISH SOME THROUGH THIS
EVENING BUT WITH CLEAR SKIES TEMPERATURES WILL QUICKLY FALL.
ANOTHER WIND CHILL ADVISORY WILL LIKELY BE NEEDED FOR TONIGHT BUT
TO AVOID CONFUSION OVER ADDITIONAL HEADLINES I LEFT THAT DECISION
FOR THE DAY SHIFT. NONETHELESS IT WILL REMAIN COLD.

ATTENTION THEN TURNS TO THE SYSTEM COMING IN FOR SUNDAY. A DEEP
UPPER LEVEL TROUGH OVER THE WEST WILL SHIFT INTO THE PLAINS
SATURDAY NIGHT THEN ACROSS THE UPPER MIDWEST SUNDAY AND SUNDAY
NIGHT. AT THE SURFACE A LOW WILL SWING OUT OF THE SOUTHWEST INTO
NORTHERN MISSOURI THEN NORTH CENTRAL ILLINOIS SUNDAY EVENING.
THERE WILL BE SEVERAL WAVES MOVE ACROSS IOWA DURING THIS TIME SO
IT LOOKS AS THOUGH SOME LIGHT SNOW WILL BE POSSIBLE LATE SATURDAY
NIGHT WITH THE FIRST WAVE OF THETA-E ADVECTION THEN AS THE PIECES
OF ENERGY COME ACROSS IOWA SUNDAY THERE WILL BE GENERALLY A LIGHT
TO MODERATE SNOWFALL WITH PERIODS OF MODERATE SNOWFALL. THE LAST
COUPLE OF DAYS THE MODELS HAVE BEEN SUGGESTING A 2 TO 5 INCH SNOW
FALL ACROSS CENTRAL IOWA WITH 2 INCHES ACROSS THE SOUTHEAST AND 5
ACROSS THE FAR NORTHWEST AND WEST. SNOW TO LIQUID RATIONS CONTINUE
TO BE FROM 15 TO 25 TO 1 SO IT WILL NOT TAKE MUCH QPF TO GET
MEASURABLE SNOW. THERE IS STILL SOME UNCERTAINTIES IN THE FINER
DETAILS WHICH WILL PRECLUDE ANY HEADLINES AT THIS TIME BUT WE WILL
CONTINUE TO MONITOR TRENDS.

THE SYSTEM WILL DEPART EARLY MONDAY THEN ANOTHER BLAST OF COLD AIR
WILL COME LATE MONDAY AND TUESDAY USHERED IN BY SOME STRONG WIND.
HOWEVER WITH THE FRESH SNOW FROM SUNDAY...THE WIND MAY CREATE SOME
ISSUES WITH VISIBILITY. WE WILL BE MONITORING THAT AS WELL BUT
WILL GET A BETTER HANDLE ON THAT ONCE WE SEE WHERE THE HEAVIEST
SNOW FALLS. TEMPS MAY MODERATE SOME BY LATE IN THE EXTENDED BUT I
AM NOT PUTTING MUCH WEIGHT IN THAT AS THIS IS DAY 6 AND 7 AND WE
ARE GOING TO HAVE SNOW ON THE GROUND WHICH WILL DEFINITELY IMPACT
TEMPS.

&&

.AVIATION...06/18Z
ISSUED AT 1125 AM CST FRI DEC 6 2013

VFR CONDITIONS EXPECTED AT SITES THROUGH PERIOD. WINDS WILL REMAIN
TO THE NORTHWEST AND BECOME LIGHTER AFTER 00Z.

&&

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

&&

$$

SHORT TERM...SMALL
LONG TERM...FAB
AVIATION...AWB