FXUS63 KDMX 151112 AAA
AFDDMX
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE DES MOINES IA
511 AM CST TUE DEC 15 2009
...UPDATED AVIATION DISCUSSION...
.SHORT TERM /TODAY/...
ANOTHER COOL AND QUIET DAY IN STORE AS HIGH PRESSURE MOVES IN FROM
THE WEST. NORTHWEST WINDS SHOULD REMAIN FAIRLY STEADY AS EXPECTED
SPEED INCREASE WITH DAYTIME MIXING WILL BE MITIGATED BY CLOSER
PROXIMITY OF THE HIGH AS THE MORNING PROGRESSES. VERY COLD
TEMPERATURES THIS MORNING STILL SUPPORT WIND CHILL VALUES OF -20 TO
-30 ACROSS ABOUT OUR NORTHERN HALF...IN SPITE OF RELATIVELY LOW WIND
SPEEDS...SO WIND CHILL ADVISORY WILL REMAIN UNCHANGED WITH MORNING
ISSUANCE. MADE LITTLE CHANGE IN MAX TEMPS TODAY AS VIRTUALLY CLEAR
SKIES WILL BE OFFSET BY LOW SOLAR ANGLE AND ENTRENCHED COLD AIR OVER
REMAINING SNOWPACK FROM LAST WEEKS STORM.
.LONG TERM /TONIGHT THROUGH MONDAY/...
A FAIRLY NON DESCRIPT UPPER LEVEL NORTHWEST FLOW PATTERN UNTIL
LATE IN THE WEEK...WITH TEMP TRENDS REALLY THE ONLY CHALLENGE.
LOW LEVEL RIDGE AXIS PASSES EAST OF THE CWA BY MIDNIGHT
TONIGHT...WITH WARM ADVECTION ENSUING FOR THE LATTER HALF OF THE
NIGHT. THEREFORE...HAVE A NON DIURNAL TREND FOR TONIGHT...WITH
TEMPS DROPPING RAPIDLY AT SUNSET AND SLOWLY WARMING THEREAFTER.
SOUTHERLY FLOW WEDNEDAY WILL BOOST TEMPS IN THE UPPER TEENS NORTH TO
UPPER 20S SOUTH.
BAROCLINIC ZONE DEVELOPS NEAR THE IA/MO BORDER BACKING OUR FLOW
MORE OUT OF THE EAST OR NORTHEAST. UPPER LEVEL FLOW BUCKLES BY
FRIDAY AS SHORTWAVE ENERGY MOVING ACROSS THE NRN ROCKIES DIVES
SOUTHEAST TO THE SOUTHERN PLAINS. CONSENSUS AMONG THE MODELS IS TO
KEEP BETTER KINEMATIC AND THERMODYNAMIC FORCING SUPPRESSED SOUTH
OF IOWA INTO THE WEEKEND. HOWEVER...ECMWF IS A LITTLE FARTHER
NORTH...AND WITH GENERAL TROUGHINESS ALOFT OVER THE AREA FRIDAY
THROUGH SATURDAY...HAVE MAINTAINED SLIGHT CHC SNOW DURING THIS
PERIOD. WILL HAVE COLDER TEMPS AGAIN FOR THE WEEKEND...THOUGH NOT
AS COLD AS TODAY.
&&
.AVIATION...
15/12Z...VFR CONDITIONS EXPECTED FOR THE NEXT 24 HOURS. SURFACE HIGH
PRESSURE WILL MOVE EASTWARD ROUGHLY ALONG THE IOWA/MISSOURI
BORDER...MAINTAINING WEST NORTHWEST BREEZES THROUGH THE MORNING THAT
WILL DIMINISH LATE THIS AFTERNOON AND TONIGHT AS THEY TURN TO
SOUTHWEST THEN SOUTH. A FEW CLOUDS BASED AROUND FL070-080 WILL MOVE
ACROSS THE AREA THIS MORNING...POSSIBLY PRODUCING SOME BRIEF VFR
CIGS. HIGHER CLOUDS AROUND FL120-150 WILL MOVE IN TONIGHT BUT SHOULD
REMAIN THIN.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY UNTIL 10 AM CST THIS MORNING FOR AUDUBON-
BLACK HAWK-BOONE-BREMER-BUTLER-CALHOUN-CARROLL-CERRO GORDO-
CRAWFORD-EMMET-FRANKLIN-GREENE-GRUNDY-GUTHRIE-HAMILTON-HANCOCK-
HARDIN-HUMBOLDT-KOSSUTH-MARSHALL-PALO ALTO-POCAHONTAS-SAC-STORY-
TAMA-WEBSTER-WINNEBAGO-WORTH-WRIGHT.
&&
$$
SHORT TERM/AVIATION...LEE
LONG TERM...MOYER
