FXUS63 KDMX 302359
AFDDMX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
600 PM CST MON NOV 30 2009
.SHORT TERM /TONIGHT/...
DRY NORTHWEST FLOW ALOFT AND SOUTHWEST FLOW AT THE SURFACE WILL
PERSIST THROUGH TONIGHT. DECOUPLING AROUND SUNSET WILL ALLOW WINDS
TO DIMINISH SOME...BUT THE PRESSURE GRADIENT SHOULD KEEP A GENTLE
BREEZE BLOWING IN MOST SPOTS THROUGH THE NIGHT. THEREFORE...EXPECT
OVERNIGHT MIN TEMPS TO NOT DROP AS FAR AS LAST NIGHT...AND TO BE
REASONABLY HANDLED BY THE GUIDANCE. WILL GO WITH A MAV/MET BLEND.
.LONG TERM /TUESDAY THROUGH MONDAY/...
CURRENT MILD WX PATTERN ABOUT TO COME TO AN ABRUPT HALT BY WED...
BUT STILL NICE THROUGH TUES. MODELS CONTINUE TO SHOW WARMEST AIR TO
JUST BYPASS THE FORECAST AREA TUESDAY. DESPITE THAT H850 TEMPS STILL
WARM INTO THE 6 TO 8C RANGE FOR THE MORNING HOURS WITH THE FRONT
ARRIVING BY MID TO LATE AFTERNOON. COLDER AIR TO SLOWLY FILTER IN
THE REGION TUESDAY NIGHT AND WEDNESDAY WITH 15 TO 20F DROP IN HIGH
TEMPERATURES IN THE 24 HOURS. SECONDARY ARCTIC FRONT TO DROP SOUTH
WED NIGHT AS SOUTHERN STREAM LOW DEEPENS EAST. ALONG WITH THAT
STRONGER UPPER LEVEL H500 LOW WILL EXPAND SOUTH AND BEGIN TO CUT
OFF...BECOMING A PARENT OR ANCHOR LOW ACROSS THE GREAT LAKES FOR
SEVERAL DAYS. DEEP COLD TEMPERATURES PLUS STEEP LAPSE RATES WILL
PROMOTE FLURRIES OR SNOW SHOWERS ACROSS THE REGION FOR THE LATE
MORNING AND AFTERNOON HOURS. SOUNDINGS ACROSS THE NORTH DONT SUGGEST
GUSTY WINDS TO 25 MPH FOR THURSDAY...BUT DO SHOW 5000FT HIGH RH WITH
THE ENTIRE CLOUD IN THE DENDRITIC LAYER BELOW 750MB. CAPE IS RATHER
LIMITED...BUT PERHAPS ENOUGH TO GENERATE SOME SNOW SHOWER ACTIVITY
NORTHERN SECTIONS WITH FLURRIES CENTRAL AND SOUTH. SOUNDINGS REMAIN
STEEP OVERNIGHT AND WILL EXPECT WINDS TO REMAIN IN THE 15 TO 25 MPH
RANGE FOR THURSDAY NIGHT AND EARLY FRIDAY. AS PER THE EURO MODEL
YESTERDAY...THE GFS IS FINALLY SLOWING THE DEPARTURE OF THE LARGE
UPPER LEVEL TROUGH THROUGH SATURDAY. THIS IS ALSO SIMILAR TO THE
UKMET FOR THAT TIME PERIOD. HOWEVER...MODEL DISCREPANCIES BEGIN TO
AGAIN APPEAR AT DAY 5 AND BEYOND WITH THE GFS ONCE AGAIN LEADING THE
PACK OF CHANGE. THOUGH A PATTERN CHANGE IS DEFINITELY IN THE OFFING
AS THE UPPER LEVEL LOW EXITS AND THE PATTERN TRANSITIONS TO A ZONAL
AND THEN A MORE WEST SOUTHWEST FLOW AFT THE 7 DAY PERIOD...THE GFS
IS ON TRACK TO HAVE THE REGION IN SOUTHWEST FLOW ALOFT BY LATE SAT
AND SUNDAY WITH A SHORT WAVE EJECTING ACROSS THE REGION SUNDAY. THIS
SCENARIO WOULD BRING SNOW TO THE STATE WHILE THE 00Z EURO SUGGESTED
A MODERATION FOR SUNDAY. NEW 12Z EURO SUGGESTS LITTLE IF ANY ENERGY
MOVING EAST UNTIL LATER ON MONDAY. THUS...WILL BE TRENDING TOWARD
THE SLOWER EURO MODEL FOR THE WEEKEND AND MONDAY FORECASTS. PATTERN
STILL TO UNDERGO A DRAMATIC CHANGE FOR THE PERIOD FOLLOWING THIS
FORECAST...AND IT APPEARS MUCH MORE WINTER-LIKE.
&&
.AVIATION...
01/00Z...VFR CONDITIONS EXPECTED THROUGHOUT THE FORECAST PERIOD WITH
SOME SCT-BKN CIRRUS CLOUDS AND SOUTHWEST WINDS.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...MOYER
LONG TERM...REV
AVIATION...BEERENDS