| HOME | ARCHIVES | FORECASTS | IMAGERY | ABOUT NHC | RECONNAISSANCE |

Eastern Pacific Tropical Weather Discussion (Text)



000
AXPZ20 KNHC 310311
TWDEP 

TROPICAL WEATHER DISCUSSION                                      
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
0405 UTC MON AUG 31 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 
0315 UTC.               

...SPECIAL FEATURE...

MAJOR STRONG CATEGORY FOUR HURRICANE JIMENA IS CENTERED NEAR 
15.0N 132.5W OR ABOUT 1524 MILES E OF HILO HAWAII AT 0300 
UTC...MOVING WNW OR 290 DEG AT 14 KT. THE MAXIMUM SUSTAINED WIND 
SPEED IS 130 KT WITH GUSTS TO 160 KT AND ESTIMATED MINIMUM 
PRESSURE HAS DECREASED TO 936 MB. LATEST SATELLITE IMAGERY SHOWS 
THAT JIMENA HAS A DISTINCT 20 NM WIDE EYE. THE OVERALL CLOUD 
PATTERN WITH JIMENA HAS BECOME VERY SYMMETRICAL AND BETTER 
ORGANIZED DURING THE PAST 6-12 HOURS. NUMEROUS MODERATE/ISOLATED 
STRONG CONVECTION SURROUNDS THE 10 NM WIDE EYE WITHIN 120 NM IN 
THE NE AND SW QUADRANTS...150 NM IN THE SE QUADRANT AND 90 NM IN 
NW QUADRANT. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS 
SEEN IN BANDS ELSEWHERE WITHIN 300 NM NE AND 120 NM SW 
SEMICIRCLES OF THE THE CENTER...AND ALSO SSW OF JIMENA WITHIN 60 
NM OF A LINE FROM 04N140W TO 07N132W TO 09N128W. JIMENA IS 
FORECAST TO TRACK ALONG THE WESTERN PERIPHERY OF A SUB-TROPICAL 
RIDGE THROUGH EARLY NEXT WEEK REACHING NEAR 17N139W BY TUE 
AFTERNOON. JIMENA IS PRODUCING A LARGE AREA OF 12 FT OR GREATER 
SEAS OUTWARD TO 290 NM N AND 240 NM S OF THE CENTER WITH 
SURROUNDING AREA TO 20-33 KT WINDS AND SEAS OF 8-11 FT ARE 
EXPECTED TO EXPAND TO ABOUT 300 SE AND 540 NM NW SEMICIRCLES OF 
THE CENTER BY TUE. 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 

A 1008 MB LOW PRES SYSTEM IS EMBEDDED IN THE MONSOON TROUGH NEAR 
11N108W...AND IS SLOWLY MOVING WESTWARD. SCATTERED MODERATE 
ISOLATED/STRONG CONVECTION IS WITHIN 60 NM OF THE LOW CENTER... 
AND WITHIN 240 NM IN THE SW QUADRANT. SIMILAR ACTIVITY IS IN 
BANDS WITHIN 60 NM OF A LINE FROM 13N105W TO 10N102W. LAST 
VISIBLE IMAGERY DEPICTED INCREASING BANDING FEATURES AROUND THE 
CENTER OF THE LOW. THE PRES GRADIENT HAS TIGHTENED E OF THE LOW 
ENHANCING THE SOUTHWESTERLY MONSOONAL FLOW TO 20-25 KT WITHIN 90 
NM SE SEMICIRCLE OF THE CENTER WITH SEAS OF 7-9 FT. ELSEWHERE 
WITHIN 240 NM OF THE CENTER...WINDS ARE 10-20 KT WITH SEAS OF  5-
7 FT. THE LOW IS FORECAST TO REACH NEAR 12N112W BY EARLY MON 
EVENING...AND TO NEAR 15N115W BY EARLY TUE EVENING. EXPECT THE 
20-25 KT WINDS TO GRADUALLY INCREASE TO 25-30 KT OVER THE NEXT 
24-48 HOURS AS THE LOW BECOMES BETTER ORGANIZED ALONG WITH SEAS 
POSSIBLY BUILDING RATHER QUICKLY. CONDITIONS ARE FAVORABLE FOR A 
MEDIUM PROBABILITY OF TROPICAL CYCLONE FORMATION OF THE LOW OVER 
THE NEXT 48 HOURS AS JIMENA PULLS FURTHER TO THE W AND AWAY FROM 
IT.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...            

THE MONSOON TROUGH AXIS EXTENDS WSW OFF THE PACIFIC COAST OF 
COSTA RICA AT 09N85W...AND GRADUALLY CONTINUES NW TO 11N94W TO 
13N102W...THEN TURNS SW TO LOW PRES NEAR 11N108W TO 10N114W TO 
11N118W WHERE IT LOSES IDENTITY. SCATTERED MODERATE/ISOLATED 
STRONG CONVECTION IS WITHIN 180 NM S OF THE TROUGH BETWEEN 85W-
90W AND BETWEEN 112W-115W. SCATTERED MODERATE CONVECTION IS FROM 
08N-14N BETWEEN 97W-102W. ELSEWHERE SCATTERED MODERATE 
CONVECTION IS WITHIN 60 NM OF A LINE 07N113W TO 08N118W.

SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS ALONG AND 
WITHIN 60 NM OF THE COAST OF COSTA RICA AND NORTHERN PANAMA
BETWEEN 82W-86W.

...DISCUSSION...

A SURFACE RIDGE EXTENDS SE FROM 32N136W TO 17N104W. THE GRADIENT 
IS SUPPORTING 15-20 KT TRADES ACROSS THE WATERS S OF THE RIDGE 
WITH COMBINED SEAS OF 6-8 FT IN MIXED NW AND CROSS EQUATORIAL S 
SWELL. LITTLE CHANGE EXPECTED THROUGH TUE THEN THESE CONDITIONS 
WILL SHIFT WESTWARD AS JIMENA CROSSES 140W ON WED. THE GRADIENT 
E OF THE RIDGE IS SUPPORTING NW 15-20 KT WINDS ACROSS THE 
SUBTROPICS E OF 122W TO THE BAJA CALIFORNIA PENINSULA WITH 
COMBINED SEAS OF 6-8 FT ACROSS THE DISCUSSION. THE GRADIENT WILL 
RELAX ON MON INTO TUE WITH SEAS SUBSIDING TO 4-7 FT BY TUE 
EVENING.

$$
AGUIRRE

Standard version of this page

Alternate Formats
About Alternates - E-Mail Advisories - RSS Feeds

Cyclone Forecasts
Latest Advisory - Past Advisories - About Advisories

Marine Forecasts
Latest Products - About Marine Products

Tools & Data
Satellite Imagery - US Weather Radar - Aircraft Recon - Local Data Archive - Forecast Verification - Deadliest/Costliest/Most Intense

Learn About Hurricanes
Storm Names Wind Scale - Prepare - Climatology - NHC Glossary - NHC Acronyms - Frequently Asked Questions - AOML Hurricane-Research Division

About Us
About NHC - Mission/Vision - Other NCEP Centers - NHC Staff - Visitor Information - NHC Library

Contact Us


NOAA/ National Weather Service
National Centers for Environmental Prediction
National Hurricane Center
11691 SW 17th Street
Miami, Florida, 33165-2149 USA
nhcwebmaster@noaa.gov
Disclaimer
Privacy Policy
Credits
About Us
Glossary
Career Opportunities
Page last modified: Monday, 31-Aug-2015 03:11:16 UTC