173
FXUS63 KDMX 161745
AFDDMX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
1245 PM CDT WED OCT 16 2013
.SHORT TERM.../TODAY /...
ISSUED AT 312 AM CDT WED OCT 16 2013
LOW PRESSURE SYSTEM WILL CONTINUE TO LIFT NORTHEAST AWAY FROM
IOWA...WITH GRADUALLY DIMINISHING LIGHT RAIN AND DRIZZLE ACROSS THE
NORTH AND EAST THROUGHOUT THE EARLY MORNING HOURS. HAVE KEPT POPS
DRY THROUGH THE DAY...THOUGH LOCALIZED AREAS OF DRIZZLE MAY PERSIST
FOR A FEW HOURS AFTER SUNRISE. MAIN FORECAST CONCERN FOR THE DAY
THEN BECOMES CLOUD COVER AND AFFECT ON TEMPERATURES. HAVE INCREASED
CLOUDINESS THROUGH THE DAY...AS HIGH RES MODELS AND SOUNDINGS
INDICATE ENOUGH MID LEVEL MOISTURE TO KEEP STRATUS ACROSS MUCH OF
THE AREA THROUGH EARLY AFTERNOON. VERY WEAK WAA WILL PUSH INTO
WESTERN IOWA LATE IN THE DAY...AND HAVE BUMPED TEMPERATURES UP A FEW
DEGREES IN THE WEST...THOUGH HAVE KEPT TEMPERATURES COOL WITH
ANTICIPATED CLOUD COVER THROUGH THE DAY.
.LONG TERM.../TONIGHT THROUGH TUESDAY/...
ISSUED AT 312 AM CDT WED OCT 16 2013
EXTENDED CONTINUES TO LOOK BELOW NORMAL. MEAN H500 TROUGH WILL
PUSH SYSTEMS ACROSS CANADA RECURVING SOUTH INTO THE GREAT LAKES.
THIS WILL RESULT IN BOUTS OF COOL AIR BEING DRIVEN INTO THE
FORECAST AREA WITH BRIEF WARM UPS FROM TIME TO TIME. IN THE SHORT
TERM...MODELS IN AGREEMENT WITH A SERIES OF WAVES AND FAST MOVING
COLD FRONTS APPROACHING FROM THE NORTHWEST THROUGH FRIDAY NIGHT.
AFTER SOME CHILLY AIR OVER THE REGION TONIGHT AND PATCHY FROST
MAINLY NORTH...THE FIRST WAVE WILL ARRIVE THURSDAY EVENING WITH A
BAND OF CLOUDS MARKING ITS ARRIVAL. PRIOR TO IT...SLIGHTLY WARMER
TEMPERATURES PASS OVER THE AREA THURSDAY. HIGHS WILL REACH THE
UPPER 50S NORTH TO THE LOWER 60S SOUTHEAST. THE SECOND FRONT WILL
QUICKLY FOLLOW FRIDAY NIGHT WITH LITTLE RECOVERY IN HIGHS ON
FRIDAY. THE SECOND FRONT HAS EVEN COLDER AIR ASSOCIATED WITH
IT...H850 TEMPS DROPPING TO 2C SOUTH TO -4C NORTH BY 00Z SUNDAY.
FRIDAY WILL MOST LIKELY SEE MORE CLOUDS THAN SUNSHINE. AT THIS
POINT...HIGHS SHOULD BE HELD BACK TO THE LOWER 50S NORTH TO THE
MID TO UPPER 50S IN THE SOUTH. SOME CLOUDS WILL HANG ON OVERNIGHT
FRIDAY NIGHT WITH LOWS IN THE 30S REGION WIDE. THOUGH THERE IS A
SIGNAL FOR SOME SUNSHINE IN THE AFTERNOON SATURDAY...STRATUS MAY
FILL IN OVER PORTIONS OF THE REGION BY THE AFTERNOON HOURS
RESULTING IN AN EVEN CHILLIER DAY. AT THIS POINT...HIGHS SHOULD BE
HELD BACK TO THE UPPER 40S TO NEAR 50F NORTH TO THE MID TO UPPER
50S IN THE SOUTH. WITH A WEAK RIDGE OF HIGH PRESSURE SETTLING OVER
THE AREA SATURDAY NIGHT...A VERY COLD NIGHT IS IN STORE FOR THE
NORTHEAST AT LEAST...POSSIBLY THE CENTRAL AS WELL. MODELS DIVERGE
TO SOME DEGREE ON RETURN OF WARMER AIR TO THE WEST. A RATHER SHARP
STATIONARY BOUNDARY MORE TYPICAL OF WINTER WILL BEGIN MOVING EAST
SATURDAY. IF IT ARRIVES SOON ENOUGH WEST BY 12Z SUNDAY...CLOUD
COVER ASSOCIATED WITH IT SHOULD MITIGATE THE OVERNIGHT FALL IN
TEMPERATURES. HOWEVER THE NORTHEAST AND PARTS OF NORTHERN IOWA
WILL HAVE A BETTER CHANCE OF CLEAR SKIES...AND ALONG WITH THE
SUBDUED HIGHS FROM SATURDAY ...A HIGHER LIKELIHOOD OF READINGS IN
THE LOWER 30S BY SUNDAY MORNING. TIMING ISSUES AND SOME
UNCERTAINTY WILL PROBABLY PLAY OUT OVER THE NEXT FEW FORECAST
CYCLES. THE REMAINDER OF THE EXTENDED PERIOD WILL TAKE A FEW MORE
MODEL RUNS TO SETTLE ON A CONSISTENT SOLUTION. THE GEM/EURO MODEL
HAVE BEEN ATTEMPTING TO BRING A VERY COLD AIRMASS INTO THE GREAT
LAKES AND UPPER MIDWEST BY TUESDAY AND WEDNESDAY OF NEXT WEEK. THE
GFS IS SHOWING SIMILAR THERMAL CHARACTERISTICS BUT IT PULLS A
DIGGING CLIPPER FARTHER EAST THAN THE GEM/EURO. THIS HAS SOME
IMPLICATIONS AS FOR PRECIPITATION CHANCES BY EARLY TO MIDWEEK NEXT
WEEK. SOME HINT AT THE POSSIBILITY OF A MIXTURE OF PRECIPITATION
AS WELL...BUT WILL WAIT FOR SOME CONSISTENCY IN SOLUTIONS OVER THE
NEXT FEW DAYS.
&&
.AVIATION...16/18Z
ISSUED AT 1240 PM CDT WED OCT 16 2013
DEPARTURE OF STRATUS DECK IS THE FORECAST ISSUE. EXPECT CLOUD
CEILINGS TO GRADUALLY RISE INTO THE VFR RANGE WEST OF I-35 AND
MVFR RANGE EAST THROUGH THE AFTERNOON. DEPARTURE WILL BE
SLOWEST...POSSIBLY NOT UNTIL 17/06Z UNDER THE CYCLONIC FLOW. THERE
MAY BE ENOUGH RESIDUAL SURFACE MOISTURE FOR SOME FOG TO DEVELOP AT
KMCW AND KALO TOWARD MORNING...BUT WITH SOME CIRRUS COVER AND FLOW
TURNING AROUND TO THE SOUTHWEST DID NOT FORECAST MUCH IN THE WAY
OF VISIBILITY RESTRICTIONS.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...AWB
LONG TERM...REV
AVIATION...JUNGBLUTH