110
FXUS63 KDMX 130837
AFDDMX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
337 AM CDT TUE AUG 13 2013
.SHORT TERM.../TODAY /...
ISSUED AT 323 AM CDT TUE AUG 13 2013
LITTLE OF CONCERN TODAY WITH IA STILL INFLUENCED BY FRINGE OF NRN
PLAINS SURFACE HIGH PRESSURE SO FORECAST REMAINS DRY WITH NIL
SYNOPTIC SCALE FORCING. HOWEVER IT IS INTRIGUING THAT THE 03Z
SREF...00Z GFS AND SEVERAL HI RES MODELS DEPICT A SMALL NNW-SSE
ORIENTED BAND OF SHOWERS DURING PEAK HEATING WITHIN VERY SUBTLE
SURFACE CONVERGENCE. ALTHOUGH IT CANNOT BE RULED OUT AND MULTIPLE
MODELS DO SHOW COINCIDENT AREAS OF TOKEN SB/MLCAPES WITHIN NO
CINH...REALLY CANNOT SEE CONVERGENCE IN THIS WEAK NELY SURFACE LOW
BEING SUFFICIENT TO DEVELOP ANYTHING.
EXAMINATION OF MON HIGHS VS PAST AND PRESENT MODEL SOUNDINGS
SUGGESTS COOLER TEMPS TODAY WITH HIGHS AT OR JUST ABOVE THE HIGHER
END OF MOS GUIDANCE. MIXING TO AROUND 5KFT WILL ALSO DROP DEWPOINTS
DOWN INTO THE LOW/MID 50S BY AFTERNOON...CERTAINLY PLEASANT AND
ATYPICAL FOR MID AUGUST.
.LONG TERM.../TONIGHT THROUGH MONDAY/...
ISSUED AT 323 AM CDT TUE AUG 13 2013
MAIN FORECAST FEATURE IN THE LONGER TERM IS THE RETREAT OF THE
HIGH AND WHAT TO DO WITH THE THE UPPER LEVEL SYSTEM IN THE WED-FRI
TIME FRAME. MODELS SEEM TO BE COMING TOGETHER WITH THE EVOLUTION.
THE GFS IS THE MOST AGGRESSIVE AND MAY BE OVERDONE...BUT THE IDEA
SEEMS REASONABLE. INSTABILITY IS THERE WITH MOISTURE STREAMING IN
AND K INDICES RISING INTO THE 30S. THE TRANSPORT IS WEAK AND FEEL
THE LOWER AMOUNTS OF THE ECMWF MAY BE THE BETTER WAY TO GO HERE.
WITH ONLY 10 TO 15 KTS OF CONVERGENCE AT 805 MB...THIS IS NOT
SUPPORTIVE OF WIDESPREAD LARGE AMOUNTS. AFTER THIS SYSTEM MOVES
OFF...THE PATTERN WILL TURN DRY AGAIN. FEEL THE TREND OF THE GFS
IS ON TRACK WITH THE WARMING IN THE LATER PERIODS INTO WEEK 2.
ECMWF IS SOFTEST ON THE HEATING...THE GFS STRONGEST. SUPPORT FOR
THE WARMING IN THE 6 TO 12 DAY PERIOD COMES FROM POSITIONING OF
MJO...ALBEIT WEAK...SHIFT IN PNA FROM POSITIVE TO NEGATIVE...AND
LACK OF ANY RECURVATURE OF TYPHOON UTOR...19N 114E...SUGGESTIVE OF
RISING HEIGHTS IN EASTERN NOAM IN ABOUT A WEEK.
&&
.AVIATION...13/06Z
ISSUED AT 1148 PM CDT MON AUG 12 2013
VFR CONDITIONS ARE EXPECTED TO PERSIST THROUGH THE PERIOD. LIGHT
NORTH TO NORTHWEST WINDS WILL GRADUALLY SWITCH TO NORTHEAST ON
TUESDAY. LOCALIZED FOG POSSIBLE TONIGHT THOUGH THE POTENTIAL AT ANY
SITES IS LOW. A FEW BKN CIGS AROUND 5-6 KFT EXPECTED BY TUESDAY
AFTERNOON.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SMALL
LONG TERM...MS AUG 13
AVIATION...DONAVON