000
AXPZ20 KNHC 161535
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL 
1605 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 ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1445 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... 
            
MONSOON TROUGH AXIS FROM 09N78W TO 14N91W...THEN RESUMES FROM 
14N107W TO 09N120W TO 08N132W TO 07N140W.

...DISCUSSION...

THE POST TROPICAL REMNANT LOW PRES OF MANUEL WAS CENTERED JUST 
INLAND OVER THE STATE OF JALISCO NEAR 21.1N 105.2W AT 16/1500Z. 
ESTIMATED PRES IS 1003 MB WITH MOVEMENT TO THE NW AT 7 KT. A 
LARGE AREA OF CONVECTION ACCOMPANIES THE REMNANT LOW WITHIN 120 
NM OF THE COAST OF MEXICO FROM 18N TO 23N...ASSOCIATED WITH THE 
EASTERLY FLOW ON THE N SIDE OF THE PRES CONVERGING WITH THE 
MODERATE TO FRESH W TO NW FLOW MOVING ONSHORE. THE CONVECTION 
HAS BEGUN TO WEAKEN...DUE TO NORMAL DIURNAL TRENDS. THE LOW PRES 
IS EXPECTED TO DRIFT NW AND MOVE OFFSHORE LATER TODAY. 

THE OVERALL SEA LEVEL PRES REMAINS VERY LOW ALONG THE NW COAST 
OF MEXICO. WHILE TROPICAL CYCLONE FORMATION IS NOT 
EXPECTED...GLOBAL MODELS SUGGEST THERE WILL BE SPURIOUS LOW PRES 
AREAS BETWEEN THE SOUTHERN TIP OF THE BAJA PENINSULA AND CABO 
CORRIENTES OVER THE NEXT COUPLE OF DAYS...AT THE BASE OF A SHARP 
LOW TO MID LEVEL TROUGH EXTENDING ROUGHLY DOWN THE LENGTH OF THE 
GULF OF CALIFORNIA. IN THE MID TO UPPER LEVELS...A SHARP TROUGH 
THAT REACHED FROM THE GREAT BASIN ACROSS THE SOUTHERN ROCKIES 
AND NW MEXICO TO THE SOUTHERN GULF OF CALIFORNIA IS WEAKENING. 
THIS TROUGH HAD BEEN PROVIDING CONSIDERABLE UPPER SUPPORT TO THE 
CONVECTION E OF 105W ASSOCIATED WITH MANUEL OVER THE PAST COUPLE 
OF DAYS. WEAK LOWER TO MID LEVEL TROUGH IS EXPECTED TO REMAIN IN 
PLACE OVER THIS AREA THROUGH MID WEEK...ENHANCING COASTAL 
CONVECTION MAINLY AT NIGHT.

A PARTIAL OSCAT PASS FROM 0730 UTC INDICATED THE SURGE OF FRESH 
TO STRONG SW FLOW WITHIN 240 NM S OF THE MONSOON TROUGH BETWEEN 
100W TO 110W. CONCURRENT ALTIMETER PASSES INDICATES SEAS IN 
EXCESS OF 11 FT WITH HIGHEST SEAS ESTIMATED AROUND 13 FT NEAR 
THE COAST. THE WINDS AND SEAS WILL GRADUALLY DIMINISH AS THE 
OVERALL MONSOON GYRE WEAKENS AND REORIENTS ITSELF WESTWARD. 
DESPITE THE WEAKENING TREND...THE STRONG SW FLOW WILL CONTINUE 
TO POSE A RISK OF DANGEROUS SURF AND RIP CURRENTS ALONG COASTAL 
AREAS FROM WESTERN OAXACA TO MICHOACAN THROUGH TODAY. RAINFALL 
WILL ALSO CONTINUE TO BE AN ISSUE AS MOIST ONSHORE FLOW PUSHES 
INTO THE COASTAL MTNS...PROLONGING THE RISK OF ISOLATED AREAS OF 
FLOODING AND MUDSLIDES. 

CLUSTERS OF STRONG SHOWERS AND THUNDERSTORMS ARE ACTIVE ALONG 
THE COASTS OF PANAMA AND COSTA RICA...WHERE OVERNIGHT DRAINAGE 
FLOW IS CONVERGING WITH LIGHT TO MODERATE SW FLOW. 

FARTHER WEST...1029 MB HIGH PRES IS CENTERED NEAR 37N153W WITH A 
RIDGE EXTENDING W TO THE COAST OF BAJA CALIFORNIA NORTE. ASCAT 
DATA FROM 04 UTC INDICATED 15 TO 20 KT NW FLOW ALONG THE COAST 
OF THE BAJA PENINSULA AND S OF THE SOUTHERN TIP OF THE PENINSULA 
TO 15N...BETWEEN THE TROUGH OVER NW MEXICO AND RIDGE.

ELSEWHERE...LIGHT TO MODERATE WINDS AND SLIGHT SEAS PREVAIL WITH 
NO SIGNIFICANT CONVECTION NOTED.
 
$$
COBB