000
AXPZ20 KNHC 092131
TWDEP 

TROPICAL WEATHER DISCUSSION                                    
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
2205 UTC TUE SEP 09 2014

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 
2100 UTC.

...SPECIAL FEATURE...                                           
A 1009 MB LOW PRES IS CENTERED NEAR 14N101W MOVING NW AT 5 KT. A 
TROPICAL WAVE EXTENDS NORTHWARD FROM THE LOW TO THE COAST OF 
MEXICO NEAR 18N ALONG 101W AND THE OVERALL CIRCULATION REMAINS 
EMBEDDED WITHIN THE MONSOON TROUGH FROM 12N TO 17N BETWEEN 97W 
AND 105W. STRONGEST CONVECTION CONTINUES TO OCCUR WITHIN THE 
NORTH SEMICIRCLE AS SCATTERED MODERATE FROM 13N TO 18N BETWEEN 
99W AND 105W. PERIODS OF HEAVY RAINFALL MAY ALSO OCCUR ALONG AND 
IMMEDIATELY INLAND ACROSS THE COAST OF MEXICO BETWEEN PUERTO 
ANGEL AND MANZANILLO DURING THE NEXT 48 HOURS. ENVIRONMENTAL 
CONDITIONS ARE EXPECTED TO BE FAVORABLE FOR THIS LOW TO DEVELOP 
OVER THE NEXT COUPLE OF DAYS AS IT SLOWLY MOVES NW. THERE IS A 
HIGH PROBABILITY OF THIS FEATURE DEVELOPING INTO A TROPICAL 
CYCLONE. PLEASE REFER TO THE LATEST EASTERN PACIFIC TROPICAL 
WEATHER OUTLOOK FOR FURTHER INFORMATION.   

...TROPICAL WAVES...                                          
TROPICAL WAVE EXTENDS FROM 11N TO 23N ALONG 86W MOVING W AT 10-
15 KT. A SMALL PORTION OF THE WAVE IMPACTS THE EAST PACIFIC 
REGION NORTH OF THE MONSOON TROUGH AXIS. MOST OF THE LOW-LEVEL 
TROUGHING ASSOCIATION WITH THIS FEATURE REMAINS ACROSS THE 
WESTERN CARIBBEAN SEA. SCATTERED MODERATE CONVECTION IS 
OCCURRING ACROSS NICARAGUA AND HONDURAS THIS EVENING.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...           
THE MONSOON TROUGH EXTENDS FROM 10N86W TO 1009 MB LOW PRES NEAR 
14N101W TO 14N107W TO 1008 MB LOW PRES NEAR 12N116W TO 1009 MB 
LOW PRES NEAR 11N125W TO 11N132W. THE ITCZ EXTENDS FROM 11N132W 
TO 10N140W. SCATTERED MODERATE CONVECTION IS FROM 05N TO 09N 
BETWEEN 83W AND 88W...FROM 07N TO 12N BETWEEN 96W AND 101W...AND 
FROM 06N TO 10N BETWEEN 119W AND 127W. ISOLATED MODERATE 
CONVECTION IS FROM 09N TO 13N BETWEEN 124W AND 131W.            

...DISCUSSION...

ALOFT...AN ANTICYCLONE IS CENTERED OVER WEST TEXAS WITH A RIDGE 
EXTENDING W-SW OVER NORTHERN BAJA CALIFORNIA...THEN TO ANOTHER 
ANTICYCLONIC CIRCULATION CENTERED NEAR 28N119W. THE INFLUENCE OF 
THIS RIDGING ALOFT IMPACTS MUCH OF THE NORTHERN FORECAST WATERS 
N OF 20N PROVIDING RELATIVELY DRY AND STABLE CONDITIONS 
SUPPORTING SURFACE RIDGING AND WINDS GENERALLY LESS THAN 15 KT 
WITH THE EXCEPTION OF THE REMNANT LOW OF NORBERT CENTERED OFF 
THE NORTHERN BAJA COAST NEAR 28N118W. 

AT THE SURFACE...A 1027 MB HIGH IS CENTERED WELL N-NW OF THE 
AREA NEAR 43N140W EXTENDS A WEAK RIDGE SE INTO THE FORECAST AREA 
NEAR 30N130W EXTENDING TO NEAR 18N113W. THE PRESSURE GRADIENT 
BETWEEN THE RIDGE AND LOWER PRESSURE ASSOCIATED WITH THE MONSOON 
TROUGH AND IN THE VICINITY OF THE ITCZ IS SUPPORTING GENTLE TO 
MODERATE TRADE WINDS OVER THE WATERS W OF 120W. 

THE LOW NEAR 12N116W OF 1008 MB IS FORECAST TO MOVE IN A GENERAL 
NORTHWARD DIRECTION OVER THE NEXT 48 HOURS...WHILE THE 1009 MB 
LOW NEAR 11N125W MOVES TO THE NE PER GLOBAL MODEL GUIDANCE. SW 
FLOW S OF THESE FEATURES IS EXPECTED TO INCREASE THROUGH THE 
NEXT COUPLE OF DAYS WITH SEAS MAINTAINING A RANGE OF 8 TO 10 FT 
WITHIN SW SWELL. 

THE REMNANT LOW OF NORBERT CONTINUES TO SPIN NEAR 28N118W WITH 
FRESH TO STRONG WINDS LINGERING WITHIN 90 NM OF THE WESTERN 
SEMICIRCLE OF THE LOW WITH SEAS REMAINING LESS THAN 8 FT. THE 
LOW WILL CONTINUE TO WEAKEN OVERNIGHT INTO WEDNESDAY WITH 
ASSOCIATED WINDS AND SEAS LOSING ADVISORY CRITERIA DURING THE 
NEXT FEW HOURS.

$$ 
HUFFMAN