152  
AXPZ20 KNHC 130941  
TWDEP  
 
TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL  
1005 UTC SUN MAY 13 2018  
 
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  
09415 UTC.  
   
..INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH
 
 
 
THE MONSOON TROUGH AXIS EXTENDS FROM NORTHWESTERN COLOMBIA TO  
07N78W TO 07N90W TO 10N100W TO LOW PRESSURE NEAR 11N114W 1012 MB  
TO ANOTHER 1012 MB LOW NEAR 14N130W AND TO 08N140W. SCATTERED  
MODERATE ISOLATED STRONG CONVECTION IS SEEN WITHIN 180 NM SOUTH  
OF THE AXIS BETWEEN 115W AND 117W, AND WITHIN 60 NM SOUTH OF THE  
AXIS BETWEEN 78W AND 79W. SCATTERED MODERATE CONVECTION IS  
WITHIN 60 NM SOUTH OF THE AXIS BETWEEN 89W AND 91W, AND ALSO  
WITHIN 30 NM OF THE AXIS BETWEEN 105W AND 107W.  
   
..DISCUSSION
 
 
OFFSHORE WATERS WITHIN 250 NM OF MEXICO...  
 
THE COMBINATION OF LOW PRESSURE OVER THE SOUTHWESTERN UNITED  
STATES THAT COVERS THE NORTHERN AND CENTRAL MEXICO, WITH HIGH  
PRESSURE THAT NOSES EASTWARD TOWARDS NORTHERN BAJA CALIFORNIA  
AND THE NORTHERN SECTION OF THE GULF OF CALIFORNIA CONTINUES  
TO INDUCE A TIGHT GRADIENT OVER THOSE AREAS. THIS GRADIENT  
PRESENTLY SUPPORTS SOUTHWEST WINDS OF 20 TO 25 KT ACROSS THE  
NORTHERN GULF OF CALIFORNIA AND BAJA CALIFORNIA NORTE. THE  
GRADIENT WILL RELAX ENOUGH JUST AFTER DAYBREAK TO ALLOW FOR THESE  
WINDS TO DIMINISH TO THE MODERATE TO FRESH SPEEDS, WITH SEAS OF  
3 TO 5 FT. WINDS OVER THE REST OF THE GULF WILL BE LIGHT TO  
GENTLE AT MOSTLY GENTLE SPEEDS. THE MODERATE TO FRESH WINDS OVER  
THE NORTHERN GULF OF CALIFORNIA WILL ALSO BECOME LIGHT TO GENTLE  
VARIABLE WINDS THIS AFTERNOON. THESE WINDS THEN BECOME SOUTHEAST  
TO SOUTH AT GENTLE TO MODERATE SPEEDS TONIGHT, AND SOUTH TO  
SOUTHWEST FRESH TO STRONG WINDS FOR A BRIEF TIME DURING THE  
OVERNIGHT HOURS. THEY THEN BECOME LIGHT TO GENTLE VARIABLE WINDS  
ON MON, WITH A REPETITION OF THE FRESH TO STRONG SOUTH TO  
SOUTHWEST WINDS DURING MON NIGHT. WEAK LOW PRESSURE IS FORECAST  
TO FORM TUE ON THE NORTHERN SEGMENT OF THE GULF OF CALIFORNIA  
THERMAL TROUGH. THIS WILL BRING CYCLONIC WINDS OF GENTLE TO  
MODERATE SPEEDS OVER THE NORTHERN GULF TUE, HOWEVER THE LOW IS  
EXPECTED TO BECOME DIFFUSE BY EARLY TUE EVENING ALLOWING FOR  
WINDS TO BECOME VARIABLE AT LIGHT SPEEDS.  
 
NORTHERLY GENTLE TO MODERATE WINDS WILL REMAIN OVER THE OFFSHORE  
WATERS W OF BAJA CALIFORNIA THROUGH TUE AFTERNOON, THEN INCREASE  
TO FRESH TO STRONG WINDS BEGINNING WED NIGHT AS HIGH PRESSURE W  
OF BAJA CALIFORNIA STRENGTHENS SLIGHTLY AND WHILE AT THE SAME  
TIME IT BUILDS EAST-SOUTHEASTWARD. SEAS OF 6 TO 8 FT IN LONG  
PERIOD NW SWELL, SUBSIDING TO 5 TO 7 FT TONIGHT. OVER THE GULF OF  
TEHUANTEPEC, WINDS WILL BRIEFLY BECOME NW TO N AT MODERATE TO  
FRESH SPEEDS EARLY ON MON BEFORE BECOMING MODERATE TO SOUTH TO  
SOUTHWEST WINDS DURING MON AFTERNOON.  
 
FARTHER SOUTH IN THE GULF OF TEHUANTEPEC, MAINLY LIGHT TO GENTLE  
WINDS ARE EXPECTED TODAY. WITH SEAS OF 5 TO 7 FT IN LONG PERIOD  
SOUTHERLY SWELL. WINDS WILL BRIEFLY BECOME NW TO N AT MODERATE  
TO FRESH SPEEDS EARLY ON MON BEFORE BECOMING MODERATE SOUTH TO  
SOUTHWEST WINDS DURING THE AFTERNOON.  
 
OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND  
WITHIN 750 NM OF ECUADOR...  
 
GULF OF PAPAGAYO: MODERATE TO FRESH NORTHEAST TO EAST WINDS ARE  
EXPECTED ACROSS THE GULF OF PAPAGAYO THROUGH EARLY THIS AFTERNOON,  
THEN BECOME VARIABLE GENTLE TO MODERATE WINDS. SEAS ARE FORECAST  
TO BE IN THE 4 TO 6 FT RANGE THROUGH MOST OF TONIGHT BEFORE THEY  
BECOME MODERATE EAST WINDS EARLY MON, THEN MAINLY GENTLE SOUTH  
TO SOUTHWEST WINDS THROUGH MON NIGHT AND NORTHEAST TO EAST  
GENTLE TO MODERATE WINDS DURING TUE.  
 
GULF OF PANAMA: GENTLE TO OCCASIONALLY MODERATE SW WINDS ARE  
FORECAST DURING THE NEXT SEVERAL DAYS, WITH SEAS OF 4 TO 6 FT  
IN LONG PERIOD SOUTHERLY SWELL THROUGH MON BEFORE SUBSIDING  
SLIGHTLY TUE.  
 
REMAINDER OF THE AREA...  
 
A RIDGE EXTENDS FROM A 1026 MB HIGH PRESSURE, CENTERED WELL  
NORTH OF THE AREA NEAR 46N136W, SOUTHEASTWARD TO NEAR THE  
REVILLAGIGEDO ISLANDS. LOW PRESSURE, REMNANTS OF RECENT TROPICAL  
DEPRESSION ONE-E, IS NEARLY STATIONARY NEAR 14N130W WITH A  
CENTRAL PRESSURE OF 1013 MB. THE SMALL CYCLONIC CIRCULATION OF  
THE LOW IS CLEARLY EXPOSED, AND WILL BECOME ILL-DEFINED WITH  
TIME. LATEST SATELLITE IMAGERY SHOWS A WEAKENING ISOLATED  
THUNDERSTORM WELL TO THE NORTHEAST OF THE LOW WITHIN 30 NM OF  
15N127W. THE LOW IS FORECAST TO BEGIN TO DRIFT SOUTHWARD THIS  
AFTERNOON THROUGH TONIGHT AS THE HIGH PRESSURE RIDGING TO ITS N  
BEGINS TO BUILD SOUTHWARD. THE LOW IS THEN FORECAST TO OPEN UP TO  
A TROUGH MON AFTERNOON.  
 
NORTHWEST SWELL PRODUCING SEAS WITH PEAK VALUES OF UP 12 FT  
UPSTREAM OF 32N, WILL CONTINUE TO PROPAGATE SOUTH-SOUTHEASTWARD  
TO THE SOUTH OF 32N REACHING AS FAR SOUTH AS 22N BY EARLY THIS  
AFTERNOON BEFORE DECAYING BELOW 8 FT BY TONIGHT.  
 
AS PREVIOUSLY MENTIONED, A 1009 MB LOW IS EMBEDDED WITHIN THE  
MONSOON THROUGH NEAR 11N114W. LATEST SATELLITE IMAGERY SHOWS  
BROAD CYCLONIC TURNING WITH THE LOW-LEVEL CLOUDS ASSOCIATED  
WITH THIS LOW, HOWEVER, DEEP CONVECTION WITHIN ITS IMMEDIATE  
VICINITY IS LIMITED AND OBSERVED TO BE RATHER SPORADIC. SCATTERED  
MODERATE ISOLATED STRONG CONVECTION IS WITHIN 270 NM OF THE LOW  
IN ITS S QUADRANT, AND WITHIN 30 NM OF 11N112W. SCATTERED  
MODERATE CONVECTION IS NOTED WITHIN 30 NM OF 12N113.5W. A  
DIFFLUENT PATTERN ALOFT TO THE EAST OF A MID TO UPPER-LEVEL  
TROUGH, THAT IS LOCATED ROUGHLY BETWEEN 110W AND 120W AND NORTH  
OF 12N AS SEEN IN WATER VAPOR IMAGERY, IS HELPING TO SUPPORT THE  
AFOREMENTIONED CONVECTIVE ACTIVITY. IN ADDITION, THIS ACTIVITY IS  
UNDER BROAD ANTICYCLONIC FLOW THAT MAY HELP TO SUSTAIN IT, AND  
ANY ADDITIONAL ACTIVITY THAT MAY DEVELOP, WELL INTO THE UPCOMING  
WEEK. ACCORDING TO THE GLOBAL MODELS, THE LOW SHOULD PERSIST  
OVER THE NEXT 48 TO 72 HOURS AS IT TRACKS IN A GENERAL WEST TO  
WEST- SOUTHWEST DIRECTION.  
 

 
AGUIRRE  
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab TPC Page Main Text Page