000
AXPZ20 KNHC 291548
TWDEP 

TROPICAL WEATHER DISCUSSION                                      
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
1605 UTC SAT AUG 29 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1545 UTC.               
   
...SPECIAL FEATURE...

HURRICANE JIMENA IS CENTERED NEAR 12.5N 125.6W OR ABOUT 1255 
MILES W-SW OF THE SOUTHERN TIP OF THE BAJA CALIFORNIA PENINSULA 
AT 1500 UTC. ALTHOUGH THE 10 NM WIDE EYE HAS PRONOUNCED 
TROCHOIDAL OSCILLATION THE GENERAL MOTION IS W OR 275 DEG AT 7 
KT. JIMENA IS FORECAST TO TURN W-NW AND ACCELERATE LATER TODAY 
THROUGH MON. ESTIMATED MINIMUM CENTRAL PRESSURE IS 936 MB. THE 
MAXIMUM SUSTAINED WINDS ARE 130 KT WITH GUSTS TO 160 KT AND AND 
JIMENA IS FORECAST TO REMAIN A MAJOR HURRICANE THROUGH MON...THEN
JIMENA IS FORECAST TO BEGIN TO WEAKEN.

CURRENTLY NUMEROUS STRONG CONVECTION IS NOTED WITHIN 90 NM NE 
AND WITHIN 60 NM SW SEMICIRCLES OF CENTER SURROUNDING THE EYE. 
SCATTERED MODERATE TO STRONG CONVECTION IN BANDS IS OBSERVED 
ELSEWHERE WITHIN 240 NM NE AND 390 NM SW SEMICIRCLES OF CENTER. 
THE SURROUNDING AREA TO 20-33 KT WINDS AND SEAS OF 8-11 FT ARE 
EXPECTED TO EXPAND OUTWARD TO WITHIN 420 NM N AND 240 NM S 
SEMICIRCLES OF THE CENTER ON MON. REFER TO THE LATEST NHC 
FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP3/WTPZ23 KNHC 
AND HIGH SEAS FORECAST UNDER AWIPS/WMO HEADERS MIAHSFEPI/FZPN02 
KWBC FOR ADDITIONAL DETAILS 

...TROPICAL LOWS...

A 1008 MB SURFACE LOW IS EMBEDDED IN THE MONSOON TROUGH NEAR 
10N105W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS 
OBSERVED WITHIN 390 NM OF THE LOW CENTER. THE LOW WILL CONTINUE 
W FOR THE NEXT SEVERAL DAYS ACCOMPANIED BY 10-15 KT CYCLONIC 
FLOW. 
  
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...            

THE MONSOON TROUGH EXTENDS SW OFF THE PACIFIC COAST OF COLOMBIA  
AT 08N78W TO 08N80W...THEN TURNS NW TO 10N89W...THEN TURNS SW TO 
09N97W...THEN TURNS NW AGAIN TO AN EMBEDDED LOW PRES AT 
10N105W...THE CONTINUES SW 07N115W WHERE IT LOSES IDENTITY. 
SCATTERED MODERATE ISOLATED STRONG CONVECTION IS OBSERVED 
ELSEWHERE WITHIN 180 NM EITHER SIDE OF A LINE FROM 05N78W TO 
11N106W TO 08N118W. 

...DISCUSSION...

A WEAK SURFACE HIGH PRESSURE IS ANALYZED NEAR 29N127W WITH A  
RIDGE EXTENDING SE TO NEAR 18N112W. THE HIGH WILL BLOCK THE 
FORWARD ADVANCE OF A WEAK COLD FRONT CURRENTLY EXTENDING SW FROM 
32N129W TO 29N140W. EXPECTING A SW-W-NW-N 5-10 KT WIND SHIFT 
NEAR THE FRONTAL BOUNDARY TILL IT DISSIPATES ON SUN. THE 
GRADIENT WELL E OF THE RIDGE WILL TIGHTEN ON MON INCREASING THE 
NW FLOW TO 15-20 KT WITHIN 330 NM W OF THE NORTHERN BAJA 
CALIFORNIA PENINSULA WITH SEAS BUILDING 6-9 FT BRIEFLY ON MON.   
                                                   
GULF OF TEHUANTEPEC...A 20-25 KT NORTHERLY SURGE LAST NIGHT WILL 
DIMINISH TO 15-20 KT BY EARLY THIS AFTERNOON WITH THE 5-8 FT 
SEAS OBSERVED AT SUNRISE THIS MORNING SUBSIDING TO 4-6 FT LATE 
TODAY. TONIGHTS DRAINAGE IS EXPECTED TO MAX AT 20 KT WITH SEAS 
BUILDING TO 7 FT.

$$
NELSON