000
AXPZ20 KNHC 300905
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC WED JAN 30 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0900 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS FROM 09N84W TO 05N92W WHERE LOW LEVEL 
WINDS SUGGEST A TRANSITION TO ITCZ WHICH EXTENDS TO 07N104W TO 
04N122W TO BEYOND 07N140W. NO SIGNIFICANT CONVECTION WAS NOTED.

...DISCUSSION...

STRONG HIGH PRESSURE 1039 MB IS CENTERED N OF THE AREA NEAR 
38N133W WITH ASSOCIATED RIDGE EXTENDING TO NEAR 15N105W. THE 
PRESSURE GRADIENT BETWEEN THE AREA OF HIGH PRESSURE AND LOWER 
PRESSURE IN THE VICINITY OF THE ITCZ IS MAINTAINING STRONG 
TRADES OVER MUCH OF THE FORECAST AREA N OF 10N AND W OF 120W. 
THE RIDGE WILL WEAKEN DURING THE NEXT 24-48 HOURS WHICH WILL 
DECREASE THE AREAL COVERAGE OF THE STRONG TRADEWINDS. 

THE PRESSURE GRADIENT BETWEEN THE RIDGE AND LOWER PRESSURES OVER 
MEXICO ARE RESULTING IN FRESH TO STRONG WINDS IN THE SOUTHERN 
HALF OF THE GULF OF CALIFORNIA. HIGH PRESSURE WILL BUILD ACROSS 
THE GREAT BASIN REGION TODAY WITH BROAD TROUGHING INCREASING 
OVER MEXICO. THIS WILL EXPAND THE STRONG WINDS ALONG MUCH OF THE 
GULF OF CALIFORNIA...WITH WINDS IN PORTIONS OF THE GULF REACHING 
NEAR GALE BY EARLY THURSDAY. THE AREA OF HIGH PRESSURE WILL THEN 
WEAKEN THURSDAY AND RELAX THE PRESSURE GRADIENT TO BRING WINDS 
BELOW ADVISORY CRITERIA BY FRI MORNING. 

GAP WINDS...A COLD FRONT IN THE FAR NW GULF OF MEXICO WILL 
RAPIDLY SHIFT ACROSS THE GULF OF MEXICO...REACHING THE BAY OF 
CAMPECHE THIS EVENING. A DENSER AIR MASS BEHIND THIS FRONT WILL 
FUNNEL THROUGH THE CHIVELA PASS INTO THE GULF OF TEHUANTEPEC. 
WINDS WILL RAPIDLY RAMP UP TO GALE FORCE BY 06 UTC THU...AND 
STRONG GALE FORCE BY 12 UTC THU. STRONG HIGH PRES BUILDING 
BEHIND THE FRONT IN THE GULF OF MEXICO WILL HELP TO MAINTAIN 
THESE CONDITIONS. CURRENT MODEL GUIDANCE (10M WINDS) IS CAPPED 
AT 45 KT ALTHOUGH THERE EXISTS A POSSIBILITY FOR MINIMAL STORM 
FORCE WINDS (30M GUIDANCE WINDS ARE UP TO 50-65 KT) WHICH WILL 
NEED TO BE MONITORED IN CASE THE WARNING NEEDS TO BE UPGRADED 
PRIOR TO THE EVENT.

NE-E 20-25 KT WINDS WILL CONTINUE TO PULSE IN THE GULF OF 
PAPAGAYO DURING THE NEXT FEW DAYS. THE STRONGEST WINDS WILL 
OCCUR DURING THE LATE NIGHT AND EARLY MORNING HOURS WITH THE 
ADDED COMPONENT OF NOCTURNAL DRAINAGE FLOW...AND WEAKER WINDS 
DURING THE AFTERNOON AND EARLY EVENING HOURS.

FRESH TO STRONG WINDS WILL SPREAD ACROSS THE ISTHMUS OF PANAMA 
TO THE GULF OF PANAMA BY THU EVENING FROM THE SW CARIBBEAN 
SEA...BUILDING SEAS TO UP TO 9 FT DOWNWIND OF THE GULF BY FRI.

$$
AL