FXUS63 KDMX 061729 AAA
AFDDMX
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE DES MOINES IA
1228 PM CDT MON OCT 6 2008
UPDATED AVIATION DISCUSSION
.SHORT TERM.../TODAY/
SITUATION LOOKS TO CHANGE LITTLE UNTIL LATER THIS AFTERNOON WITH
ONSET OF PRECIP BIGGEST QUESTION. MID/HIGH CLOUDS SHOULD CONTINUE
TO STREAM NORTHWARD AHEAD OF HIGH PLAINS TROUGH. STRONGER SHORT
WAVE NOW MATURING OVER TX IS EXPECTED TO REACH KS/OK BY 00Z WITH
DEEPER MOISTURE AND FORCING AHEAD OF IT REACHING SWRN IA AFTER
20Z. NEARLY ALL DETERMINISTIC MODELS AND SUGGESTIONS FROM
ENSEMBLES SUPPORT THIS SCENARIO AS 300-310K ISENT LAYER SATURATES.
THUS HAVE SLIGHT AND EVENTUALLY LOW CHANCE WORDING CREEPING SLOWLY
EWD THIS MORNING INTO EARLY AFTERNOON FOLLOWED BY SLIGHTS TO
LIKELIES FROM E TO SW LATE.
RAISED HIGH TEMPS SEVERAL DEGREES BASED ON RELATIVELY WARM CURRENT
OBS AND SUN HIGHS. MUCH LIKE YESTERDAY...WARMER NAM SOUNDINGS SEEM
TO HAVE A BETTER HANDLE ON REALITY AND SUPPORT THIS AS WELL. CLOUDS
MAY HOLD THINGS BACK SOMEWHAT...BUT WINDS/MIXING AND A FEW BREAKS
SHOULD BE ENOUGH TO REACH FORECAST HIGHS.
.LONG TERM.../TONIGHT...SUNDAY/
WITH DEEPENING TROUGH TO THE WEST AND STRONG SOUTHERLY FLOW IN
PLACE...VERY SUMMER LIKE AIR MASS TO CONTINUE OVER THE AREA PRIOR TO
THE TROUGH PASSAGE ON TUESDAY NIGHT/WED. GFS/NAM SIMILAR IN TIMING
WITH LOW ARRIVING BY TONIGHT...THOUGH GFS A BIT FASTER IN BRINGING
SYSTEM IN NORTH INTO IOWA. BOTH MODELS ALSO HINTING AT UPPER LEVEL
BOUNDARY WITH NORTHERN STREAM KICKER WAVE HELPING TO PUSH THE
SOUTHERN STREAM WAVE FARTHER EAST TUES...RESULTING IN A MARKED SHIFT
WITH THE BEST MOISTURE TRANSPORT DURING THE NIGHT TIME HOURS TNT.
THUS...TWO FAVORED AREAS OF PRECIP DEVELOP. ONE NORTHWEST ALONG THE
SFC/UPPER LEVEL COLD FRONT ACROSS THE WEST/CENTRAL AND ANOTHER
FARTHER SOUTHEAST AND EAST OF THE FORECAST AREA BY TUESDAY. THOUGH
POP STILL LOOKS HIGH AT ALL LOCATIONS...QPF LOOKS MORE VARIABLE WITH
THE BULK OF IT NORTHWEST AND WEST WITH ANOTHER AREA EAST. MIGHT BE
SOME LESSER AMOUNTS CENTRAL WHEN ALL SAID AND DONE. GENERALLY STILL
LOOKING AT .50 TO 1.5 TOTALS OVER THE REGION. TEMPS CONTINUE ON THE
MILD SIDE TNT WITH WARM SOUTHERLY FLOW AHEAD OF THE FRONT. BY EARLY
TOMORROW MORNING...GFS SHOWS NW FLOW WILL TAKE OVER WITH CAA
FOLLOWING PASSAGE OF FRONT. WITH THE GFS...DECENT SUBSIDENCE AND
CLEARING BEHIND THE BOUNDARY WILL PROMOTE MIXING WITH NW 15-25 MPH
WHILE NAM IS STILL SLOWER IN SYSTEM EXITING THE REGION...SIMILAR TO
YESTERDAYS MODELS. OTHER THAN THE NAM...MODELS HAVE LEANED TOWARD
SPEEDING UP DEPARTURE OF FIRST SYSTEM. WITH BREAK ON SCHEDULE FOR
PART OF WED/THURS...WILL SEE SLIGHTLY WARMER AIR ON WED AFTERNOON.
NEXT UPSTREAM WAVE POSES SOME CHALLENGES AGAIN...FOR BOTH TIMING AND
PLACEMENT ISSUES. SO FAR THE EURO MODEL HAS BEEN MORE CONSISTENT
WITH THE OVERALL DEVELOPMENT AND TIMING OF THE STRONG WEEKS END
SYSTEM COMPARED TO THE GEM OR GFS. GFS CONTINUES TO HAVE DIFFERING
SOLNS WITH EACH RUN. FOR NOW AM LEANING TOWARD THE EURO WHICH HAS
SYSTEM ARRIVING LATER...WITH WAA RAINFALL BY LATE FRI OR SAT AND
INCREASING CHANCES FOR MORE WIDESPREAD RAIN AND/OR THUNDER LATE SUN
WITH STRONG H500 WAVE TRACKING FARTHER NORTHWEST. UNCERTAINTY
REMAINS RATHER LARGE TO MAKE TOO MANY CHANGES TO EXTENDED PORTION
FOR NOW...WITH PATTERN CHANGE AND MODELS LACK OF CONSISTENT HANDLING
TO CONSIDER. BUT ONE THING IS CERTAIN. LOOKING AT THE LARGE SCALE
H500 FLOW...ACTIVE WEATHER PATTERN TO REMAIN FOR A WHILE BEYOND
SUNDAY.
&&
.AVIATION...06/18Z
ONSET OF SHRA/POTENTIAL TS STILL PRIMARY FORECAST CHALLENG. TRENDS
CONTINUE TO BE A TAD SLOWER SO HAVE PUSHED BACK BEGINNING IN MANY
LOCATIONS. NOW STARTING NEAR FOD/DSM DURING THE LATE AFTERNOON OR
EARLY EVENING AND WORKING EASTWARD EVER SO SLOWLY. THUNDER COULD
OCCUR WITH ANY PERIOD OF PRECIP ESPECIALLY AT MCW/DSM/FOD...BUT HAVE
ONLY INCLUDED CB WORDING FOR NOW RATHER THAN PROLONGED MENTION. MVFR
TO LOCAL IFR CONDITIONS LIKELY TO DEVELOP A FEW HOURS AFTER SHOWERS
BEGIN. RAIN TO TAPER OFF AFT 12Z IN THE WEST WITH WIND SHIFT TO NW.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
PUBLIC...REV/BSS
AVIATION...MOYER
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