000
AXPZ20 KNHC 091600
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SAT MAR 09 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 
1545 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS SW FROM THE COAST OF COSTA RICA AT 
08N84W TO 03N86W TO WHERE SCATTEROMETER WINDS AND MODEL WIND DATA
INDICATE A TRANSITION TO AN ITCZ...THAT EXTENDS TO 01N98W TO 
02N110W TO 02N121W. SCATTERED MODERATE/ISOLATED STRONG 
CONVECTION IS WITHIN 60 NM OF THE ITCZ AXIS BETWEEN 101W-104W...
AND BETWEEN 111W-114W. SCATTERED MODERATE CONVECTION IS WITHIN
30 NM EITHER SIDE OF THE ITCZ AXIS BETWEEN 104W-107W. SCATTERED
MODERATE CONVECTION IS WITHIN 30 NM OF 06N129W.

...DISCUSSION...

A DEEP LAYERED CYCLONE IS OVER NW ARIZONA WITH A DEEP LAYERED 
TROUGH EXTENDING SW FROM IT TO ACROSS FAR NW MEXICO...TO 
NEAR 26N115W. AN UPPER CYCLONE HAS CUT OFF AT 16N143W. AN UPPER 
ANTICYCLONE IS IDENTIFIED AT 11N107W...WITH AN UPPER RIDGE 
THROUGH NW TO 21N130W TO A CREST AT 35N136W SETTING UP A LARGE 
AREA OF UPPER DIFFLUENCE BETWEEN THE TWO UPPER TROUGHS. DENSE 
DEBRIS MOISTURE IS NOTED WITHIN THE UPPER RIDGE FROM 05N TO 23N 
BETWEEN 120W AND 140W...WITH THE MOISTURE THEN CONCENTRATING 
INTO A 600 NM WIDE PLUME THAT MOVES E ACROSS CENTRAL OLD 
MEXICO...THEN TURNING NE ACROSS THE NW GULF OF MEXICO IN 
RESPONSE TO THE WESTERN CONUS TROUGH PREVIOUSLY DESCRIBED. 
AVIATORS TAKE NOTE THAT TRANSVERSE CIRRUS BANDING IS OBSERVED 
ALONG 20N BETWEEN 110W AND 130W...SUGGESTING UPPER LEVEL 
TURBULENCE. 
   
AN UPPER RIDGE EXTENDS NW FROM COLOMBIA ACROSS CENTRAL AMERICA 
TO GUATEMALA. DRY UPPER AIR IS SUPPRESSING CONVECTION ACROSS THE 
TROPICS E OF ABOUT 105W.

A 1030 MB HIGH IS ANALYZED AT 33N131W WITH A RIDGE SE TO 24N118W
TO NEAR 18N107W. NW 10 METER WINDS AT SPEEDS IN THE RANGE OF 
15-20 KT TO THE NE OF THE RIDGE ARE EXPECTED TO STRENGTHEN TO
20-25 KT LATE THIS AFTERNOON INTO THIS EVENING. SEAS OF 8 TO 11 
FT IN NW SWELLS ARE ALREADY REACHING THE BAJA CALIFORNIA 
PENINSULA N OF 27N...AND ARE EXPECTED TO SPREAD S REACHING THE 
WESTERN SHORE S OF 27N LATE BY EARLY THIS EVENING. THE PRES 
GRADIENT WILL BEGIN TO RELAX ON SUN. THE PRES GRADIENT IS ALSO 
EXPECTED TO TIGHTEN SW OF THE RIDGE TONIGHT INCREASING THE NE 
TRADES TO 20-25 KT ACROSS THE TROPICS FROM 04N TO 21N W OF 110W. 
THIS AREA OF ENHANCED NE TRADES WILL GRADUALLY SHRINK THROUGH MON
AS THE AFOREMENTIONED WEAKENS SLIGHTLY.

GAP WINDS...
GULF OF CALIFORNIA...A TROUGH WILL DEEPEN OVER INTERIOR OLD 
MEXICO AND TIGHTEN THE GRADIENT WITH NW WINDS INCREASING TO 15 
TO 20 KT TONIGHT...AND FURTHER INCREASING TO 20-25 KT BY
EARLY ON SUN FROM 22N TO 27N BETWEEN 105W-115W. BY EARLY
MON NW 20-25 KT ARE EXPECTED THROUGH THE GULF S OF 28N...BUT
WILL THEN BEGIN TO DIMINISH TO 20 KT MON AFTERNOON...AND INTO 
MON EVENING AS THE PRES GRADIENT SLACKENS. SEAS ARE EXPECTED
TO BRIEFLY PEAK TO 8 FT EARLY MON BEFORE SUBSIDING TO LESS
THAN 8 FT DURING MON AFTERNOON.

GULF OF PAPAGAYO...NE WINDS WILL CONTINUE TO PULSE AT 20 TO 25 
KT ACROSS THE WATERS FROM 09N TO 12N BETWEEN 86W-88W THROUGH 
EARLY SUN...THEN DIMINISH TO 15 TO 20 KT LATE SUN.

GULF OF TEHUANTEPEC...THE NEXT TEHUANTEPEC EVENT WILL BEGIN ON 
MON NIGHT. LATEST MODEL GUIDANCE RUNS NOW SUGGEST MINIMAL GALE 
CONDITIONS BEGINNING AROUND MIDNIGHT MON NIGHT AND CONTINUING 
THROUGH SUNRISE THU.
   
$$
AGUIRRE