000
AXPZ20 KNHC 061623
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
1605 UTC FRI NOV 06 2015

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 
1500 UTC.               

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... 
           
THE MONSOON TROUGH AXIS EXTENDS FROM 09N79W TO 12N92W TO LOW 
PRES NEAR 08N107W TO 06N110W. ITCZ AXIS EXTENDS FROM 09N125W TO 
07N140W. SCATTERED MODERATE CONVECTION IS NOTED WITHIN 180 NM S 
OF MONSOON TROUGH AXIS E OF 90W...AND WITHIN 120 NM S OF AXIS 
BEWTEEN 90W AND 100W. SCATTERED MODERATE CONVECTION IS NOTED 
FROM 03N TO 10N BETWEEN 125W AND 135W.

...DISCUSSION...

GULF OF CALIFORNIA...AN INVERTED SURFACE TROUGH EXTENDS FROM 
SOUTHERN ARIZONA NEAR 32N112W TO 28N111W TO 21N107W...WHILE 
SHARP SURFACE RIDGING IS NOSING DOWN SOUTHWARD ACROSS THE    
BAJA CALIFORNIA PENINSULA...WITH ANOTHER INVERTED SURFACE TROUGH 
REACHING FROM THE CALIFORNIA CHANNEL ISLANDS SOUTHWARD THROUGH 
29N117W TO 22N113W. THIS VERY TIGHT PRES PATTERN IS HELPING TO 
SUPPORT FRESH TO STRONG WINDS ACROSS THE GULF OF CALIFORNIA S OF 
29N WHICH WAS NICELY CAPTURED BY A RECENT ASCAT-B SCATTEROMETER 
PASS. THESE WINDS WILL CONTINUE TO BLOW THROUGH SAT DIMINISHING 
SAT NIGHT AS THE PRES GRADIENT RELAXES. SEAS WILL BUILD TO UP TO 
8 FT BY THIS AFTERNOON.

ELSEWHERE N OF 15N E OF 120W...A VIGOROUS MID/UPPER SHORT WAVE 
TROUGH IS MOVING ACROSS THE COAST OF SOUTHERN CALIFORNIA AT THE 
BASE OF A LONGER AMPLITUDE TROUGH MOVING FROM THE ROCKIES INTO 
THE CENTRAL PLAINS. THIS IS TIGHTENING THE PRESSURE GRADIENT 
ACROSS THE GULF OF CALIFORNIA...RESULTING IN FRESH TO STRONG NW 
WINDS AS NOTED IN AN ASCAT PASS FROM 04 UTC. AN ALTIMETER PASS 
FROM 13 UTC INDICATED SEAS TO 7 FT AT THE SOUTHERN END OF THE 
GULF. GIVEN THE STRENGTH...FETCH AND DURATION OF THE NW 
FLOW...SEAS TO 8 FT ARE LIKELY OVER THE SOUTHERN AND MIDDLE GULF 
BY LATE TODAY. THE WINDS AND SEAS WILL DIMINISH BY LATE SAT AS 
THE TROUGH LIFTS NE. GENERALLY MILD CONDITIONS WILL PERSIST 
THROUGH EARLY NEXT WEEK...WITH WINDS INCREASING AGAIN BY MID 
WEEK.

GULF OF TEHUANTEPEC...A RECENT ASCAT SCATTEROMETER PASS SAMPLED 
FRESH TO STRONG NORTHERLY WINDS IN THE GULF DUE TO A LOCALIZED 
TIGHT PRES GRADIENT COMBINED WITH NOCTURNAL DRAINAGE FLOW. THESE 
WINDS WILL DIMINISH JUST AFTER SUNRISE THIS MORNING AS THE 
DRAINAGE FLOW SUBSIDES. LOOKING AHEAD...A COLD FRONT IS FORECAST 
TO MOVE INTO THE WESTERN GULF OF MEXICO N OF THE AREA THIS 
WEEKEND WITH STRONG HIGH PRES AND ATTENDANT RIDGING BUILDING 
ACROSS EASTERN MEXICO. FRESH TO STRONG NORTHERLY FLOW WILL BE 
INDUCED IN THE GULF OF TEHUANTEPEC SAT NIGHT WITH MODEL GUIDANCE 
INDICATING MINIMAL GALE CONDITIONS BY SUN NIGHT...PERSISTING 
THROUGH MONDAY...THEN DIMINISHING BY MID WEEK.

ELSEWHERE N OF 15N E OF 120W...A WEAK TROPICAL WAVE IS MOVING 
THROUGH NORTHERN CENTRAL AMERICA AND SOUTHERN MEXICO...BUT WILL 
LOSE DEFINITION AS IT PUSHES INTO THE PACIFIC WATERS LATER 
TODAY. THE APPROACH OF THE TROPICAL WAVE HAS BEEN ENHANCING THE 
PULSE OF GAP WINDS THROUGH TEHUANTEPEC THIS MORNING...AS WELL AS 
CLUSTERS OF SHOWERS AND THUNDERSTORMS OFF THE COAST OF OAXACA 
EARLIER. DIVERGENCE ASSOCIATED WITH THE UPPER TROUGH IS 
ENHANCING CONVECTION NEAR A LOW PRES NEAR 14N113W.

S OF 15N E OF 110W...SCATTERED SHOWERS AND THUNDERSTORMS ARE 
ACTIVE ALONG THE MONSOON TROUGH EAST OF 90W. UPPER OUTFLOW OF 
THIS CONVECTION IS BEING ENHANCED BY SOUTHERLY FLOW ALOFT ON THE 
EAST SIDE OF AN UPPER LOW MOVING ACROSS SOUTHERN MEXICO AND 
ADJACENT WATERS. THIS PROCESS HAS ALSO BEEN SUPPLYING NORTHERLY 
FLOW INTO THE DEEP TROPICS FARTHER WEST...SUPPRESSING CONVECTIVE 
DEVELOPMENT...AND IMPACTING WEAK 1009 MB LOW PRES CENTERED NEAR 
08N107W. SW WINDS HAVE BEEN 15 TO 20 KT ON THE SE SEMICIRCLE OF 
THIS LOW...BUT HAVE SINCE DIMINISHED AS NOTED IN A 04 UTC ASCAT 
PASS. THIS WAS INTERACTING WITH LINGERING SW SWELL TO PRODUCE 
SEAS TO 8 FT...BUT THIS IS SUBSIDING AS THE WINDS DIMINISH AND 
THE SWELL DECAYS. 

ELSEWHERE...1028 MB HIGH PRES IS LOCATED NEAR 34N132W. A TIGHT 
PRES GRADIENT EXISTS ACROSS THE W CENTRAL WATERS SW OF THE 
RIDGING AND N OF THE ITCZ WITH RECENT SCATTEROMETER DATA SHOWING 
FRESH TO STRONG TRADES FROM 14N TO 20N W OF 124W. CONFUSED SEAS 
IN MIXED SWELL SURROUNDS THE AREA OF TRADES WITH COMBINED SEAS 
HEIGHT TO 8 TO 12 FT. THE FRESH TO STRONG TRADES WILL DIMINISH 
IN COVERAGE DURING THE NEXT 24-48 HOURS AS THE HIGH PRES N OF 
THE AREA WEAKENS. A 1009 MB LOW PRES AREAS ARE LOCATED NEAR 
13N121W WITH NO SIGNIFICANT CONVECTION NOTED. FRESH NE WINDS ARE 
NOTED WITHIN 120 NM OF THIS LOW. NO FURTHER DEVELOPMENT IS 
ANTICIPATED.

$$ 
CHRISTENSEN