000
AXPZ20 KNHC 160322
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL 
0405 UTC MON SEP 16 2013

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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0215 UTC.

...SPECIAL FEATURE... 

MANUEL CONTINUES TO MOVE NORTHWESTWARD THIS EVENING...AND 
FARTHER INLAND...AND HAS WEAKENED TO A TROPICAL DEPRESSION. AT 
0300 UTC...MANUEL WAS LOCATED NEAR 19.8N 104.9W MOVING NW OR 320 
DEG AT 7 KT. MAXIMUM SUSTAINED WINDS HAVE DECREASED TO 30 KT 
WITH GUSTS TO 40 KT. ESTIMATED MINIMUM PRESSURE IS 1000 MB. 
NUMEROUS STRONG THUNDERSTORMS PRODUCING TORRENTIAL RAINFALL 
CURRENTLY EXTEND FROM ABOUT 60 NM INLAND TO 120 NM OFFSHORE FROM 
NEAR ZIHUATENEJO TO CABO CORRIENTES. HEAVY RAINFALL HAS BEEN 
OCCURRING ACROSS THIS SAME AREA SINCE ABOUT NOON TODAY...AND 
ADDITIONAL RAINFALL EXPECTED ACROSS THIS AREA DURING THE NEXT 
SEVERAL HOURS WILL LEAD TO TREMENDOUS RAINFALL ACCUMULATIONS... 
AND HIGH POTENTIAL FOR FLASH FLOODING AND LANDSLIDES. 

WEAKENING OF MANUEL IS OCCURRING TONIGHT DUE TO INTERACTION WITH 
THE MOUNTAINOUS TERRAIN OF JALISCO AND GUADALAJARA...WITH THE 
LOW LEVEL CENTER BEING LEFT BEHIND...WHILE THE MIDDLE LEVEL 
CENTER IS CLEARLY EVIDENT IN SATELLITE IMAGERY MOVING NORTHWARD 
OF GUADALAJARA. ALTHOUGH THE SURFACE CENTER WILL CONTINUE TO 
MOVE NORTHWEST AND WEAKEN TONIGHT THROUGH MONDAY MORNING...AN 
ELONGATED MIDDLE LEVEL CYCLONIC CIRCULATION CONTINUES TO SPAN 
ACROSS CENTRAL MEXICO...AND WILL DRIFT SLOWLY NORTHWARD OVER THE 
NEXT FEW DAYS TO MAINTAIN VERY MOIST AND UNSTABLE CONDITIONS 
ACROSS LARGE PORTIONS OF BOTH THE CENTRAL PACIFIC AND GULF 
COASTAL ZONES OF MEXICO...AND LEAD TO CONTINUED ACTIVE 
CONVECTION WELL REMOVED FROM THE DIRECT PATH OF MANUEL. PLEASE 
SEE WMO HEADER/AWIPS HEADERS WTPZ23 KNHC/MIATCMEP3 FOR 
ADDITIONAL DETAILS.  

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... 
            
MONSOON TROUGH AXIS EXTENDS FROM COLOMBIA NEAR 08N74W TO 
10.5N81.5W TO INTERIOR HONDURAS NEAR 14.5N87W WHERE IT REMAINS 
FRACTURED...THEN RESUMES FROM 16N105W TO 09N121W TO 08N134W TO 
07N137W....WHERE IT TRANSITIONS TO ITCZ...CONTINUING ON TO 
BEYOND 07N140W. SCATTERED MODERATE TO STRONG CONVECTION WAS 
NOTED WITHIN 90 NM OF THE COAST BETWEEN 80W AND 91W. SCATTERED 
MODERATE ISOLATED STRONG CONVECTION WAS NOTED WITHIN 100 NM 
EITHER SIDE OF LINE FROM 17N101W TO 11N111W. 

...DISCUSSION...

AN UPPER TROUGH EXTENDING N TO S OVER NW MEXICO HAS SHIFTED 
SLIGHTLY WEST THIS AFTERNOON AND EVENING...AND WAS CENTERED 
ROUGHLY ALONG 108W THIS EVENING...AND CONTINUES TO PROVIDE 
DECENT ANTICYCLONIC OUTFLOW TO BOTH MANUEL AND HURRICANE INGRID 
IN THE W GULF OF MEXICO. TO THE W OF THIS TROUGH A BROAD UPPER 
RIDGE PREVAILS...CENTERED NEAR 25N121W...WITH A LARGE AREA OF 
STRONG SINKING MOTION SURROUNDING THIS HIGH. THIS RIDGE EXTENDS 
W TO JUST BEYOND 20N140W AND TO THE S TO 10N. 

AT LOW LEVELS...WELL PRONOUNCED SW MONSOONAL FLOW CONTINUES TO 
TRANSPORT ABUNDANT TROPICAL MOISTURE INTO SOUTHWEST MEXICO...TO 
THE E AND SE OF MANUEL. AT THE SURFACE...SW WINDS OF 20-30 KT 
WITH SEAS TO 15 FT EXTEND FROM ABOUT 09N11W TO THE MEXICAN COAST 
FROM OAXACA TO MANUEL. THIS VERY LONG FETCH OF SW WINDS AND THE  
DURATION OF THIS EVENT IS CAUSING ROUGH AND CONFUSED SEAS ALONG 
MUCH OF THE MEXICAN COAST FRONT THE GULF OF TEHUANTEPEC TO 
MANZANILLO...ALONG WITH LARGE AND VERY ROUGH SURF...WHICH IS 
CREATING HIGH POTENTIAL FOR COASTAL FLOODING AND RIP CURRENTS 
ALONG THE COAST. GLOBAL MODELS CONTINUE TO INDICATE THAT THE SW 
FLOW WILL GRADUALLY BEGIN TO WEAKEN MON INTO WED WITH SEAS 
SLOWLY SUBSIDING.

ELSEWHERE AT THE SURFACE...A WEAK SURFACE HIGH PRES AREA IS 
CENTERED NW OF THE AREA WITH RIDGE EXTENDING W TO THE COAST OF 
THE BAJA PENINSULA. SCATTEROMETER DATA THIS AFTERNOON INDICATED 
NW TO N AROUND 15 KT WINDS OFF THE SOUTHERN COAST OF BAJA 
PENINSULA. IN ADDITION...FRESH TO STRONG NW WINDS WERE NOTED OF 
THE COAST OF SOUTHERN CALIFORNIA...THOUGH THESE WINDS ARE 20 KT 
OR LESS S OF 30N. NO SIGNIFICANT CHANGES ARE EXPECTED THROUGH 
MID WEEK.
 
$$
STRIPLING