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000
FXUS63 KDMX 022226
AFDDMX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
426 PM CST MON DEC 2 2013

.SHORT TERM /TONIGHT/...
ISSUED AT 424 PM CST MON DEC 2 2013

SKIES ARE CLEARING RAPIDLY FROM WEST TO EAST THIS AFTERNOON...BUT
SOME HIGH CLOUDS ARE FILLING BACK IN FROM THE NORTHWEST PER
SATELLITE IMAGERY. AS EXPECTED A WARM FRONT HAS NOSED INTO OUR SOUTH
AND SOUTHWEST AND CONTINUES TO ADVANCE TOWARD CENTRAL
IOWA...BRINGING TEMPERATURES IN THE 50S WITH IT. A QUIET NIGHT IS IN
STORE AS WINDS REMAIN GENERALLY FROM THE SOUTHEAST BUT MID/HIGH
CLOUDS STEADILY THICKEN AHEAD OF AN APPROACHING LOW PRESSURE SYSTEM.
THIS WILL RESULT IN TEMPERATURES STAYING RELATIVELY WARM IN THE MID
TO UPPER 30S IN MOST AREAS OVERNIGHT. FORECAST SOUNDINGS ALSO
INDICATE THAT BY SUNRISE TUESDAY THERE WILL BE QUITE A DEEP
SATURATED LAYER ASSOCIATED WITH THE MID/HIGH CLOUDS...HOWEVER A
POWERFUL NEAR SURFACE DRY LAYER WILL REMAIN IN PLACE. THIS SHOULD
RESULT IN A SCENARIO SIMILAR TO THIS MORNING WHEREBY ANY PRECIP THAT
FORMS LATE TONIGHT WILL FALL IN THE FORM OF VIRGA EVAPORATING BEFORE
IT HITS THE SURFACE...THEN DURING THE DAY TUESDAY PRECIP WILL BE
MORE LIKELY TO REACH THE GROUND AT TIMES. THUS HAVE REMOVED POPS
OVERNIGHT...ALTHOUGH SPRINKLE WORDING MAY NEED TO BE INTRODUCED
LATER FOR THE PRE DAWN HOURS.

.LONG TERM /TUESDAY THROUGH MONDAY/...
ISSUED AT 424 PM CST MON DEC 2 2013

MAJOR CHALLENGE IN NEAR TERM IS TRACK OF LOW AND LOCATION/TIMING OF
ASSOCIATED FROPA. THE RAP HAS BEEN INITIALIZING THE BEST ALL
MORNING. BY TUESDAY AFTERNOON...GFS A LITTLE FASTER THAN RAP...AND
NAM A LITTLE SLOWER AND FURTHER SOUTH. ECMWF SEEMS TO SOMEWHAT OF AN
OUTLIER ON TRACK OF LOW. IT SEEMS THE NAM HAS THE BEST HANDLE ON THE
SITUATION...SO PUSHING BACK TIME OF COLD FROPA AND HAVE SUBSEQUENTLY
INCREASED TEMPS OVER GUIDANCE AND PVS FORECAST. ADDITIONALLY...THERE
COULD BE SOME SUNSHINE IN SOUTHWESTERN IOWA AS DRIER AIR BEING
ADCEVTED INTO LOWER LEVELS...WHICH COULD ACTUALLY HELP TEMPS WARM UP
INTO THE MID 60S. DECENT MOISTURE CONVERGENCE AND FORCING ALONG COLD
FRONT. HOWEVER...SOUNDING PROFILES NOT VERY SATURATED IN DMX CWA SO
PRECIP MAY STRUGGLE TO REACH GROUND...THUS LOW QPF FORECAST. STRONG
CAA AND TEMP GRADIENT BEHIND FRONT...SO PRECIP TYPE WILL BE TOUGH TO
PIN DOWN. THE TRANSITION ZONE FROM RANI TO SNOW WILL BE VERY NARROW.
BETTER FORCING TOWARDS MINNESOTA...SO HIGHER POPS TO THE NORTH.

FOR THURSDAY...GFS SOUNDINGS NOW KEEP THE PROFILE VERY SATURATED
DURING THE MORNING. A FEW FLURRIES MAY FALL DURING THE MORNING...BUT
NOT A LOT OF SUPPORT IN THE ATMOSPHERE FOR ANYTHING THAT WOULD
NOTABLY IMPACT THE PUBLIC. ALL MODELS HAVE SUBSIDENCE AND DRY
NORTHWESTERLY FLOW BEING ADVECTED DOWN TO CWA...ESPECIALLY THE
NAM...DURING THE AFTERNOON. THERFORE...THINK CLOUDS SHOULD BEGIN TO
BREAK UP DURING THE DAY. DUE TO LACK OF FORCING HAVE REDUCED POPS
FOR THURSDAY PM.

THURSDAY/S TEMPERATURES SLIGHTLY TRICKY. AS MENTIONED ABOVE...CLOUDS
COVER LIKELY TO BE PRESENT DURING THE MORNING BUT WILL BREAK UP
DURING THE AFTERNOON. ADDITIONALLY...IT APPEARS WIND SPEEDS WILL
REMAIN NEAR THE 10 TO 15KT RANGE. CAA THROUGHOUT THE DAY AS H850
TEMPS WILL START THE DAY AROUND -10C AND END THE DAY NEAR -13C.
THERFORE WENT SEVERAL DEGREES ABOVE GUIDANCE FOR THURSDAY
MORNING...AND WILL INCREASE DAYTIME TEMPERATURES A FEW DEGREES WITH
THE ANTICIPATED SUNSHINE. IN LOCATIONS WHERE SUN CANNOT MAKE IT
THROUGH...TEMPS WILL LIKELY HOLD STEADY OR DECREASE DURING THE DAY.

BY FRIDAY MORNING...PRESSURE GRADIENT STILL PRETTY TIGHT IN ADVANCE
OF APPROACHING HIGH SO WINDS WILL STAY AT LEAST AROUND 10 KTS.
THOUGH NOT A PURE RADIATIONAL COOLING NIGHT...WITH H850 TEMPS
APPROACHING -17C...APPARENT TEMPERATURE AT SURFACE WILL APPROACH
ZERO DEGREES...AND MAY EVEN BE BELOW ZERO IN SOME LOCATIONS. SUNNY
SKIES WILL PREVAIL FOR THE AFTERNOON...BUT HIGHS WILL STRUGGLE TO
MAKE IT OUT OF THE TEENS AS NO WAA EXPECTED.

FOR THE WEEKEND...GFS AND EURO CAME INTO SLIGHTLY BETTER AGREEMENT
WITH THEIR 12Z RUNS.  HOWEVER...THERE IS STILL QUITE A BIT OF
DISAGREEMENT. BOTH MODELS DEVELOP A SIZABLE TROUGH THAT PUSHES OFF
THE ROCKIES.  THE EURO HAS A MUCH MORE SOUTHERLY TRACK...PUTTING THE
REGION INTO SOUTHWESTERLY FLOW AND BRINGING MUCH GREATER CHANCE FOR
WINTRY PRECIP TO THE AREA. THE GFS ENSEMBLES KEEP THE LOW FURTHER
NORTH...KEPING THE CWA IN WESTERLY TO NORTHWESTERLY FLOW...WHICH
WOULD KEEP COOL...DRY AIR ALOFT AND REDUCE PRECIPITATION CHANCES
FOR DMX.

&&

.AVIATION...02/18Z
ISSUED AT 1126 AM CST MON DEC 2 2013

HIGH CEILINGS...LIGHT RAIN...AND HAZE SHOULD CLEAR OUT FROM WEST
TO EAST IN THE NEXT FEW HOURS WITH VFR CONDITIONS PREVAILING
THEREAFTER. OVERNIGHT...MID/HIGH CLOUDS BETWEEN FL070-FL120 WILL
INCREASE ONCE AGAIN AND BR WILL REDEVELOP ESPECIALLY DURING THE
MORNING HOURS TUES. EXPECT MVFR VSBYS FOR THE MOST PART AND MAYBE
A FEW LOW CLOUDS.


&&

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

$$

SHORT TERM...LEE
LONG TERM...KOTENBERG
AVIATION...LEE