000
AXPZ20 KNHC 300254
TWDEP 

TROPICAL WEATHER DISCUSSION                                     
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
0405 UTC SAT MAY 30 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0215 UTC. 

...SPECIAL FEATURE...

ANDRES...THE FIRST HURRICANE OF THE 2015 EASTERN NORTH PACIFIC 
HURRICANE SEASON...IS CENTERED NEAR 13.4N 115.2W AT 30/0300 UTC 
MOVING NW OR 320 DEG AT 6 KT. ESTIMATED MINIMAL CENTRAL PRESSURE 
IS 983 MB. MAXIMUM SUSTAINED WIND SPEED HAS INCREASED TO 75 KT 
WITH GUSTS TO 90 KT. NUMEROUS MODERATE TO STRONG CONVECTION IS 
NOTED WITHIN 60 NM OF CENTER. NUMEROUS MODERATE ISOLATED STRONG 
CONVECTION IS IN A BAND WITHIN 30 NM OF A LINE FROM 13N114W TO 
11N116W. SCATTERED MODERATE CONVECTION CAN BE FOUND ELSEWHERE 
FROM 10N TO 15N BETWEEN 111W AND 117W. SOME CONVECTIVE ACTIVITY 
IS ALSO NOTED IN A SOUTHWESTERLY FLOW FEEDING INTO THE 
HURRICANE. SWELLS GENERATED BY ANDRES COULD IMPACT THE COAST OF 
MEXICO BETWEEN CABO CORRIENTES AND LOS CABOS BY SAT EVENING 
SPREADING ALONG THE COAST OF BAJA CALIFORNIA ON SUN. REFER TO 
LATEST NHC PUBLIC/FORECAST ADVISORIES UNDER AWIPS/WMO HEADERS 
MIATCPEP1/ MIATCMEP1 AND WTPZ31/WTPZ21 KNHC FOR MORE DETAILS.  
   
...TROPICAL WAVES/LOWS...

A TROPICAL WAVE EXTENDS FROM 07N TO 15N ALONG 101W. THIS SYSTEM 
IS MOVING SLOWLY TO THE WEST DUE TO THE PRESENCE OF HURRICANE 
ANDRES. SCATTERED MODERATE CONVECTION IS SEEN ON SATELLITE 
IMAGERY FROM 10N TO 12N BETWEEN 98W AND 101W. THIS CONVECTIVE 
ACTIVITY WAS EXHIBITING SOME CYCLONIC CURVATURE. STRONG UPPER-
LEVEL WINDS ASSOCIATED WITH THE HURRICANE ARE EXPECTED TO 
INHIBIT TROPICAL CYCLONE FORMATION DURING THE NEXT COUPLE OF 
DAYS...BUT THEY ARE FORECAST TO BECOME MORE CONDUCIVE FOR 
DEVELOPMENT BY EARLY NEXT WEEK. 
 
A 1010 MB LOW PRESSURE IS LOCATED NEAR 10N138W. NUMEROUS 
MODERATE ISOLATED STRONG CONVECTION IS TO THE NW OF THE CENTER 
AND MAINLY FROM 10N TO 12N W OF 138W. THIS LOW IS EXPECTED TO 
MOVE W-SW AROUND 10 KT OVER THE NEXT TWO DAYS CROSSING 140W ON 
SUN.
 
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...

CURRENTLY THERE IS NOT A WELL DEFINED MONSOON TROUGH OR ITCZ.   

...DISCUSSION...

A RIDGE CONTINUES TO DOMINATE MOST OF THE N WATERS. THE RIDGE 
WILL WEAKEN THROUGH SUN AND SHIFT WEST AHEAD OF ANDRES 
APPROACHING FROM THE SE. THE CENTER OF ANDRES IS EXPECTED TO 
PASS WITHIN AROUND 240 NM SW OF CLARION ISLAND BY EARLY SUNDAY. 
THE CURRENT FORECAST CALLS FOR CLARION ITSELF TO REMAIN OUTSIDE 
OF THE AREA OF TROPICAL STORM FORCE WINDS...BUT WILL SEE 20 TO 
30 KT BY SUNDAY WITH SEAS OF 12-14 FT. FARTHER SOUTH...WEAK 
RIDGING OVER THE GULF OF MEXICO ALONG WITH LOWER PRES IN THE 
DEEP TROPICS OF THE EASTERN PACIFIC WILL ALLOW FRESH TO STRONG 
GAP WINDS INTO THE GULF OF TEHUANTEPEC SAT NIGHT AND SUN NIGHT 
WITH SEAS TO 7-8 FT. MARINE GUIDANCE SUGGESTS INCREASING WINDS 
TO 25-30 KT AND BUILDING SEAS TO 9 FT THROUGH THE GULF OF 
TEHUANTEPEC BY EARLY MON MORNING.

THE PRESSURE GRADIENT BETWEEN THE SUBTROPICAL RIDGE AND THE  
AFOREMENTIONED TROPICAL LOW IS MAINTAINING AN AREA OF NE-E 20 TO 
25 KT TRADE WINDS FROM 10N TO 15N W OF 134W WITH COMBINED SEAS 
TO 9 FT. 

A COLD FRONT HAS ENTERED THE NW PART OF THE FORECAST AREA AND 
CURRENTLY EXTENDS FROM 30N136W TO BEYOND 26N140W. THE FRONT WILL 
MOVE SLOWLY ON SAT EXTENDING FROM 30N134W TO 25N140W BY SAT 
NIGHT. SOME SHOWER ACTIVITY WILL BE ASSOCIATED WITH THE FRONTAL 
BOUNDARY.

$$ 
GR