000
AXPZ20 KNHC 262214
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
2205 UTC MON OCT 26 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2130 UTC.               

...SPECIAL FEATURES...

TROPICAL STORM OLAF HAS ACCELERATED IN FORWARD SPEED THIS 
AFTERNOON...AND MOVED INTO THE DISCUSSION AREA...AND WAS 
CENTERED NEAR 25.7N 138.1W AT 2100 UTC. ESTIMATED MINIMUM 
CENTRAL PRESSURE IS 992 MB. MAXIMUM SUSTAINED WIND SPEED IS 50 
KT WITH GUSTS TO 60 KT. SEE LATEST CPHC FORECAST/ADVISORY UNDER 
AWIPS/WMO HEADERS HFOTCMCP5/WTPA25 PHFO FOR MORE DETAILS. STRONG 
UPPER LEVEL SW WIND SHEAR HAS BEGUN TO IMPACT OLAF 
TODAY...AIDING IN THE ACCELERATION...AND IS ALSO BEGINNING TO 
STRETCH THE LOW LEVEL CIRCULATION E-NE TO S-SW. OLAF IS EXPECTED 
TO MOVE E-NE OVER THE NEXT 24 HOURS AND GRADUALLY WEAKEN TO A 
MINIMAL TROPICAL STORM NEAR 27.9N134.5W...THEN WEAKEN TO A 
TROPICAL DEPRESSION AND BEGIN TO MAKE AN ANTICYCLONIC TURN AS A 
COLD FRONT CURRENTLY TO THE NW OF OLAF BEGINS TO INTERACT WITH 
THE SYSTEM. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS 
OCCURRING WITHIN 240 NM ACROSS THE NE SEMICIRCLE. CURRENTLY SW 
SWELLS GENERATED BY OLAF ARE MOVING AHEAD OF THE STORM AND 
MIXING WITH LONG PERIOD NW SWELL ACROSS THE NW WATERS WITH 
COMBINED SEAS OF 8-11 FT W OF A LINE FROM 30N121W TO 20N135W TO 
19N140W.

GULF OF TEHUANTEPEC GALE WARNING...MINIMAL GALE FORCE NORTHERLY 
WINDS ARE STILL OCCURRING THIS AFTERNOON IN THE WAKE OF A STRONG 
COLD FRONT WHICH MOVED INTO THE EXTREME E BAY OF CAMPECHE AND 
PORTIONS OF THE W COAST OF THE YUCATAN PENINSULA. STRONG HIGH 
PRES RIDGING IS BUILDING SOUTHWARD ACROSS EASTERN MEXICO AND 
THIS RIDGING HAS HELPED TO PRODUCE THE STRONG TO GALE FORCE 
WINDS. SEAS ARE UP TO 12 FT JUST DOWNWIND OF THE GULF. WINDS ARE 
FORECAST TO DIMINISH BELOW GALE FORCE BY THIS EVENING...THEN 20 
KT OR LESS BY TUE EVENING WITH RESIDUAL SEAS SUBSIDING TO LESS 
THAN 8 FT BY THEN AS WELL.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... 
           
THE MONSOON TROUGH EXTENDS FROM 08N77W TO 09N95.5W TO 15N104W TO 
LOW PRES NEAR 12.5N127W TO 10N133W TO BEYOND 09N140W. SCATTERED 
MODERATE TO STRONG CONVECTION NOTED FROM 03.5N TO 09.5N E OF 
92.5W...WITHIN 120 NM N AND NE AND 240 NM S AND SW OF TROUGH 
BETWEEN 98W AND 104W...AND WITHIN 300 NM SE OF TROUGH W OF 124W. 

...DISCUSSION...

N OF 15N E OF 120W...A FAIRLY WEAK PRESSURE GRADIENT REMAINS IN 
PLACE OVER THE REGION BETWEEN 1018 MB HIGH PRES CENTERED NEAR 
42N127W AND BROAD SURFACE TROUGHING OVER NW MEXICO. RECENT SHIP 
OBSERVATIONS AND SCATTEROMETER DATA INDICATE GENERALLY LIGHT TO 
MODERATE NW FLOW PERSISTING OFF THE W COAST OF BAJA CALIFORNIA 
AND GULF OF CALIFORNIA. SEAS HAVE SUBSIDED ACROSS THE GULF OF 
CALIFORNIA TO 3 FT OR LESS W OF 110W...AND REMAIN 3-5 FT IN SE-S 
SWELL NEAR THE ENTRANCE TO THE GULF. A WEAK MID/UPPER LEVEL 
SHORT WAVE TROUGH MOVING EASTWARD ACROSS THE REGION THIS 
AFTERNOON WILL BE FOLLOWED BY ANOTHER WEAK MID/UPPER TROUGH TUE 
INTO WED...KEEPING THE RELATIVELY TRANQUIL MARINE CONDITIONS IN 
PLACE. LOOKING AHEAD...A STRONGER MID/UPPER TROUGH WITH AN 
ASSOCIATED COLD FRONT WILL APPROACH THE AREA LATE IN THE WEEK. 
THIS WILL BRING STRONG NORTHERLY FLOW TO THE WATERS NORTH OF 
GUADALUPE ISLAND...ALONG WITH A NEW ROUND OF LONG PERIOD NW 
SWELL WITH WAVE HEIGHTS 8 TO 10 FT TO THE BAJA COAST BY LATE THU.

S OF 15N E OF 110W...WEAK LOW PRES WILL CONTINUE TO OCCASIONALLY 
FORM ALONG THE MONSOON TROUGH NEAR 90W W OF COSTA RICA...BUT 
WILL REMAIN ELONGATED MAKING IT DIFFICULT TO DEPICT AS A 
DISTINCT LOW CENTER. NO SIGNIFICANT DEVELOPMENT IS ANTICIPATED 
THROUGH THE NEXT 48 HOURS. RESIDUAL SW SWELL IS MAINTAINING SEAS 
OF 5 TO 8 FT OVER MUCH OF THE AREA.

ELSEWHERE...A 1009 MB LOW PRES IS ANALYZED NEAR 12.5N127W 
EMBEDDED ALONG THE MONSOON TROUGH. EARLIER SCATTEROMETER DATA 
INDICATED MODERATE TO FRESH WINDS WITHIN 120 NM ON THE NW SIDE 
OF THE LOW WHERE RESULTANT SEAS ARE UP TO 8 FT. LITTLE CHANGE IS 
ANTICIPATED IN THE INTENSITY OF THE LOW PRES THROUGH THE NEXT 
SEVERAL DAYS AS IT DRIFTS NW...WITH A LINGERING PATCH OF FRESH 
WINDS AND SEAS TO 8 FT PERSISTING THROUGH TUE NIGHT. SEAS WILL 
INCREASE HOWEVER BY LATE WEEK WITH THE ADDITION OF LONG PERIOD 
NW SWELL INTO THIS AREA. THE NW SWELL WITH SEAS 8 TO 13 FT WILL 
ENVELOP MUCH OF THE BROADER REGION NW OF LINE FROM THE OFF BAJA 
CALIFORNIA NORTE TO 11N140W BY LATE WED.

$$ 
STRIPLING