000
FXUS63 KDMX 070448 AAB
AFDDMX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
1148 PM CDT SAT SEP 6 2008
UPDATED AVIATION DISCUSSION
.SHORT TERM /TONIGHT/...
S/WV MOVG INTO ERN NEBRASKA ATTM WILL PASS TO THE EAST OF THE CWA BY
MIDN OR SO AND THUS THE CHC FOR PCPN IS EXPECTED TO SHIFT EWD WITH
IT. CARRIED IT AS -SHRA AND LEFT THUNDER OUT. ASSUMING SOME CLRG
IN THE WAKE OF THE S/WV EXPECT TO SEE SOME FOG FORM AFT
MDNGT...THOUGH DON`T EXPECT TO HAVE WDSPRD DENSE FOG LIKE THIS MRNG.
.LONG TERM /SUNDAY THROUGH SATURDAY/...
THE MODELS HAVE BEEN QUITE CONSISTENT OVER THE PAST FEW DAYS WITH
THE SYSTEMS ON MONDAY AND WEDNESDAY NIGHT/THURSDAY AS THE BIGGER
PLAYERS IN THIS WETTER PATTERN THAT WE ARE IN. BASICALLY FORECAST
PERSISTENCE WAS PREFERRED FOR THE EXTENDED PERIODS. THE LONG WAVE
TROUGH WILL REMAIN SITUATED OVER OR JUST TO THE WEST OF THE CENTRAL
PLAINS AND WITH SEVERAL VORT MAXES SWINGING OUT OF THE BASE OF THE
TROUGH THROUGH IOWA...WE WILL SEE RAIN CHANCES CONTINUING ABOUT
EVERY 24 TO 36 HOURS. AFTER THE SHOWERS MOVE OUT BY MID MORNING WE
GET A BREAK BEFORE THE NEXT VORT MAX COMES AT US FOR MONDAY. THE
TROUGH SHARPENS WITH THIS AS IT IS A LITTLE STRONGER AND ALL MODELS
ARE PRINTING OUT A FAIR AMOUNT OF QPF. AS A RESULT...I HAVE BEEFED
UP POPS TO HIGH LIKELY AND ALSO BEEFED UP QPF. COLD AIR BEHIND THIS
SYSTEM IS STILL ON TRACK AS WE CLEAR OUT MONDAY NIGHT/TUESDAY
MORNING WILL BE UNSEASONABLY COLD. PATCHY FROST IS STILL POSSIBLE
AND WILL CONTINUE TO MONITOR BEFORE PUTTING OUT STATEMENTS. LATE
WEDNESDAY/THURSDAY THE TROUGH SHARPEN EVEN MORE AS ANOTHER STRONG
VORT MAX SWINGS DOWN IN THE FLOW. THIS TIME A SURFACE LOW AND FRONT
SETS UP AND WE GET SOME DECENT WARM ADVECTION AND WITH THE GULF
OPEN...GOOD MOISTURE ADVECTION AS WELL. INSTABILITY INCREASES
ENOUGH TO PRODUCE THUNDER AND WE STILL CANNOT RULE OUT THE
POSSIBILITY FOR SEVERE WEATHER AND HEAVY RAIN LATE WEDNESDAY THROUGH
THURSDAY.
&&
.AVIATION...07/06Z
WDSPRD VFR CIGS WL GRADUALLY PUSH EAST OVERNIGHT WITH CLEARING INTO
CENTRAL IOWA DURING THE EARLY MORNING HOURS. COMBINATION OF LIGHT
WINDS AND CLEAR SKIES ALONG WITH SOME RECENT LIGHT PCPN WL HELP
PRODUCE FOG ONCE AGAIN. HAVE LOWERED VSBYS IN TAF...ESPECIALLY AT
FAVORED TIMES AROUND SUNRISE. WL SEE VFR CONDITIONS BECOME
WIDESPREAD DURING THE DAY ON SUNDAY ALTHOUGH AN INCREASE IN VFR CIGS
CAN BE EXPECTED BY LATER IN THE DAY.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM/AVIATION...COGIL
LONG TERM...FAB
