000
AXPZ20 KNHC 142205
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC FRI SEP 14 2012

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS 
BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND 
METEOROLOGICAL ANALYSIS.

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2115 UTC.

...SPECIAL FEATURES...

TROPICAL STORM KRISTY CENTERED NEAR 20.6N 113.1W AT 2100 UTC 
MOVING NW AT 7 KT. MAXIMUM SUSTAINED WINDS 45 KT WITH GUSTS TO 
55 KT AND MINIMUM PRESSURE OF 998 MB. KRISTY IS EXHIBITING 
VERY SHARP CURVATURE TO ITS BANDING FEATURES AS THEY TIGHTLY
WRAP AROUND THE MOSTLY EXPOSED CENTER AS SEEN IN VISIBLE 
SATELLITE IMAGERY. SCATTERED MODERATE/ISOLATED STRONG CONVECTION
IS NOTED WITHIN 150 NM OF THE CENTER IN THE N AND S QUADRANTS.
KRISTY IS FORECAST TO TRACK NW OVER COOLER SEA SURFACE TEMPERATURES
DURING THE NEXT 48 HRS AND GRADUALLY WEAKEN...BECOMING A REMNANT 
LOW ON SUN. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO 
HEADERS MIATCMEP1/WTPZ21 KNHC FOR MORE DETAILS.

A TROPICAL LOW PRES MOVING WSW AT 7 KT IS JUST N OF THE MONSOON 
TROUGH NEAR 15N120W WITH AN ESTIMATED PRES AT 1007 MB. THIS
LOW HAS NOT BECOME ANY BETTER ORGANIZED SINCE 24 HOURS AGO.
SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS NOTED WITHIN
180 NM OF THE LOW IN THE SW QUADRANT. THIS SYSTEM HAS THE 
POTENTIAL TO DEVELOP INTO A TROPICAL CYCLONE AS IT TRACKS SLOWLY 
WESTWARD OVER THE NEXT COUPLE OF DAYS.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...

THE MONSOON TROUGH EXETNDS FROM 09N84W TO 08N91W WHERE IT 
TRANSITIONS TO THE ITCZ AND THEN CONTINUES TO 08N99W TO 12N108W. 
THE MONSOON TROUGH RESUMES NEAR 12N120W TO LOW PRES NEAR 14N134W 
1011 MB AND TO 11N140W. SCATTERED MODERATE ISOLATED STRONG 
CONVECTION IS WITHIN 90 NM S OF MONSOON TROUGH BETWEEN 120W AND 
125W.

...DISCUSSION...

IN THE UPPER LEVELS...LARGE SCALE MID/UPPER LEVEL RIDGING WITH 
AN ASSOCIATED MID/UPPER LEVEL ANTICYCLONE AT 20N130W COVERS
THE AREA EXCEPT IN THE FAR NW PORTION WHERE THE EASTERN EDGE OF
DEEP LAYER TROUGHING IS PRESENT.

AT THE SURFACE...A NEARLY STATIONARY SUBTROPICAL HIGH PRES 
CENTERED NEAR 38N142W EXTENDS A RIDGE SEWD THROUGH 32N129W AND 
TO NEAR 27N118W. HIGH RESOLUTION ASCAT DATA FROM THIS AFTERNOON 
SHOWED ENHANCED NE WINDS IN ENHANCE PRES GRADIENT N OF THE 
CONVERGENCE ZONE IN THE VICINITY OF THE LOW PRES NEAR 15N120W 
AND ANOTHER ONE NEAR 14N134W. BROAD LOW PRES IS PRESENT OVER 
MUCH OF AREA S OF ABOUT 23N WHERE OUTSIDE KRISTY AND THE 
TROPICAL LOWS LIGHT TO MODERATE WINDS ARE NOTED. THE LOW NEAR
15N120W IS PROGGED BY THE GLOBAL MODELS TO ACQUIRE SOME DEVELOPMENT
OVER THE NEXT 48 HOURS...WITH THE GFS STILL BEING THE MORE 
AGRESSIVE ONE WITH WINDS AND SEAS.

A SURFACE RIDGE OVER THE SW GULF OF MEXICO IS CAUSING NORTHERLY 
WINDS TO PULSE WITH A STRONG DIURNAL SIGNAL AT 20 TO 25 KT WITH 
SEAS TO 8 FT INTO AND JUST DOWNSTREAM OF THE GULF OF TEHUANTEPEC 
WITH LITTLE CHANGE EXPECTED THROUGH SUN. NE TO E WINDS ARE ALSO 
EXPECTED TO PULSE AT 15 TO 20 KT THROUGH THE GULF OF PAPAGAYO 
WITH MAX SEAS OF 7 FT JUST DOWNSTREAM OF THE GULF THROUGH SUN. 
STRONGEST GAP WINDS ARE EXPECTED TO OCCUR DURING THE LATE NIGHT 
HOURS THROUGH A FEW HOURS AFTER SUNRISE.  

$$
AGUIRRE