000
AXPZ20 KNHC 280230
TWDEP 

TROPICAL WEATHER DISCUSSION                                     
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
0405 UTC THU MAY 28 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...

SHOWERS AND TSTMS ASSOCIATED WITH A 1006 MB LOW PRES LOCATED 
NEAR 10N108W CONTINUE TO SHOW SIGNS OF ORGANIZATION. DEEP 
CONVECTION IS GRADUALLY INCREASING NEAR THE CENTER AND LATEST 
SATELLITE IMAGERY SHOWS A CLUSTER OF DEEP CONVECTION WITHIN 
AROUND 60 NM W SEMICIRCLE OF LOW CENTER. A CLUSTER OF STRONG 
CONVECTION IS ALSO NOTED FAR TO THE NW OF THE LOW CENTER FROM 
11N-13N BETWEEN 108W-110W. SCATTERED MODERATE TO ISOLATED STRONG 
CONVECTION IS NOTED ELSEWHERE FROM 11N-13N BETWEEN 104W-111W. 
THIS SYSTEM IS EXPECTED TO BECOME A TROPICAL DEPRESSION LATER 
THIS EVENING OR ON THU. THE LATEST NHC TROPICAL WEATHER OUTLOOK 
GIVES THIS LOW PRES AREA A HIGH CHANCE OF DEVELOPING INTO A 
TROPICAL CYCLONE DURING THE NEXT 48 HOURS WHILE IT MOVES W-NW AT 
AROUND 10-15 KT.
 
...TROPICAL WAVES/LOWS...

A TROPICAL WAVE EXTENDS FROM 05N-14N ALONG 97W MOVING W AT 10-15 
KT. CONVECTION ASSOCIATED WITH THIS SYSTEM HAS DIMINISHED DURING 
THE LAST FEW HOURS...AND NOW A CLUSTER OF MODERATE CONVECTION IS 
ALONG THE AXIS NEAR 08N97W. ISOLATED MODERATE CONVECTION IS NEAR 
THE NORTHERN END OF THE WAVE AXIS. ENVIRONMENT CONDITIONS COULD 
BECOME MORE FAVORABLE FOR SOME DEVELOPMENT OF THIS SYSTEM BY THE 
WEEKEND WHILE IT MOVES SLOWLY TO THE W-NW.
 
A 1007 MB SURFACE LOW PRESSURE IS ANALYZED NEAR 08N121W. A 
CLUSTER OF MODERATE TO STRONG CONVECTION HAS DEVELOPED WITHIN 
ABOUT 150 NM W QUADRANT OF LOW CENTER. PRES GRADIENT BETWEEN 
THIS LOW AND A RIDGE TO THE NORTH IS PRODUCING AN AREA OF 
MODERATE TO FRESH TRADE WINDS FROM 10N-14N BETWEEN 120W-124W 
WITH SEAS TO 8 FT. THE LOW IS EXPECTED TO DRIFT WESTWARD AND 
WEAKEN THROUGH FRI. 

A 1008 MB SURFACE LOW IS ANALYZED NEAR 11N132W. LATEST VISIBLE 
SATELLITE IMAGERY SHOWS A VERY WELL DEFINED SWIRL OF LOW CLOUDS 
IN ASSOCIATION WITH THIS SYSTEM FORECAST TO DRIFT W-SW OVER THE 
NEXT COUPLE OF DAYS LIKELY CROSSING 140W FRI NIGHT INTO SAT. THE 
PRES GRADIENT BETWEEN THE LOW AND THE RIDGE TO THE N SUPPORTS AN 
AREA OF NE 20-25 KT TRADES MAINLY FROM 11N-16N BETWEEN 130W-135W 
WITH COMBINED SEAS OF 8-9 FT. AN EARLIER SCATTEROMETER PASS 
PROVIDED OBSERVATIONS OF THESE WINDS.
 
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...

CURRENTLY THERE IS NOT A WELL DEFINED MONSOON TROUGH OR ITCZ IN 
THE EASTERN PAC DUE TO THE PRESENCE OF THREE LOW PRES SYSTEMS 
AND A TROPICAL WAVE IN CLOSE PROXIMITY OF EACH OTHER. SCATTERED 
MODERATE CONVECTION IS NOTED ACROSS THE DEEP TROPICS FROM 03N TO 
06N BETWEEN 108W AND 125W...AND FROM 01N TO 07N BETWEEN 120W AND 
126W.

...DISCUSSION...

BROAD SURFACE RIDGE ANCHORED BY 1021 MB HIGH PRES CENTERED NEAR 
30N128W EXTENDS A RIDGE ACROSS THE NORTH WATERS TO NEAR 21N112W. 
A FRONTAL THROUGH STRETCHES FROM 30N137W TO 27N138W TO BEYOND 
25N140W. THE TROUGH WILL REMAIN NEARLY STATIONARY THROUGH THU 
NIGHT...WHILE THE HIGH PRESSURE WILL MOVE TO A POSITION NEAR 
28N132W. 

GAP WINDS...MARINE GUIDANCE SUGGESTS FRESH TO LOCALLY STRONG NE 
WINDS OVERNIGHT TONIGHT INTO THU MORNING THROUGH THE GULF OF 
PAPAGAYO WITH SEAS BRIEFLY BUILDING TO 8 FT. 

FRESH NORTHERLY WINDS ARE EXPECTED ACROSS THE GULF OF 
TEHUANTEPEC DURING THE OVERNIGHT AND EARLY MORNING HOURS THROUGH 
FRI MORNING.

$$ 
GR