000
AXPZ20 KNHC 080915
TWDEP 

TROPICAL WEATHER DISCUSSION                                   
NWS NATIONAL HURRICANE CENTER MIAMI FL                       
1005 UTC TUE DEC 8 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0900 UTC.               
 
...SPECIAL FEATURES...
 
GULF OF TEHUANTEPEC GALE WARNING...A TIGHT PRESSURE GRADIENT
PERSISTS ACROSS SOUTHERN MEXICO SUPPORTING GALE FORCE NORTHERLY
WINDS. A SHIP WITH CALL SIGN BATFR53 REPORTED 30-40 KT WINDS
BETWEEN 1600-0000 UTC AS IT TRANSITED THE AREA MONDAY. MAX SEAS
ARE ESTIMATED TO BE 17-18 FT. THE PRESSURE GRADIENT IS EXPECTED
TO GRADUALLY RELAX LATER TODAY...ALLOWING WINDS TO DIMINISH
BELOW GALE FORCE EARLY WED MORNING...THEN TO 20-25 KT BY WED
AFTERNOON.

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

MONSOON TROUGH EXTENDS FROM 06N78W TO 04N83W TO 05N97W. ITCZ
EXTENDS FROM 05N97WTO 04N125W TO 06N130W. SCATTERED MODERATE
CONVECTION WITHIN 240 NM N OF AXIS BETWEEN 97W AND 103W.

...DISCUSSION...

NEARLY STATIONARY 1027 MB HIGH PRES CENTERED NEAR 30N136W WITH A
RIDGE AXIS EXTENDING SE TO NEAR 19N115W. A WEAK TROUGH S OF 08N
ALONG 131W/132W IS PRODUCING SCATTERED MODERATE CONVECTION FROM
04N-08N BETWEEN 127W-131W. FURTHER WEST...A 1008 MB LOW NEAR
05N138W IS GENERATING SCATTERED CONVECTION W OF 140W. A LARGE
SWATH OF MID-UPPER LEVEL CLOUDS ASSOCIATED WITH THE SUBTROPICAL
JET COVERS MUCH OF THE AREA FROM 13N-22N E OF 125W. THIS AREA OF
UPPER LEVEL MOISTURE WILL SPREAD ACROSS CENTRAL MEXICO TODAY.

THE GRADIENT BETWEEN THE RIDGE AND LOWER PRESSURE ASSOCIATED
WITH THE CONVERGENCE ZONE IS ENOUGH TO SUPPORT AN AREA OF FRESH
TO STRONG NE TRADES IN W CENTRAL WATERS FROM 07N-16N W OF 130W.
THE RIDGE WILL WEAKEN WED NIGHT AND THU AHEAD OF A COLD FRONT
MOVING INTO NW WATERS. THIS WILL ALLOW TRADE WINDS TO DIMINISH
WITH THE AREA OF HIGHEST WINDS SHIFTING WEST OF THE AREA ALONG
WITH THE LOW AND TROUGH MENTIONED EARLIER.

A LARGE AREA OF LONG PERIOD NW SWELL WITH SEAS GREATER THAN 8 FT
COVERS MOST OF THE WATERS W OF 100W. ALTIMETER PASSES DURING THE
PAST 6-12 HOURS SHOWED 12-14 FT SEAS W OF 135W. WAVE HEIGHTS ARE
FORECAST TO GRADUALLY SUBSIDE DURING THE NEXT 24-48 HOURS...BUT
STILL EXPECT SEAS OF 8 FT OR GREATER ACROSS THE WATERS W OF 100W
BY WED AFTERNOON.

GULF OF PAPAGAYO...FRESH TO OCCASIONALLY STRONG WINDS WILL
CONTINUE TO PULSE MAINLY DURING OVERNIGHT HOURS WITH THE AID OF
NOCTURNAL DRAINAGE FLOW. SEAS WILL OCCASIONALLY BUILD TO 8 FT
DURING THE PERIOD OF STRONGEST WINDS.

GULF OF CALIFORNIA...EARLIER ASCAT SCATTEROMETER DATA SHOWED
FRESH TO STRONG NW-N WINDS SPILLING OUT SOUTH OF 23N...BUT
CONDITIONS ARE EXPECTED TO IMPROVE BY THIS MORNING AS THE
PRESSURE GRADIENT RELAXES.

$$
MUNDELL