000
AXPZ20 KNHC 120336
TWDEP 

TROPICAL WEATHER DISCUSSION                                  
NWS NATIONAL HURRICANE CENTER MIAMI FL                      
0405 UTC SAT DEC 12 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
0100 UTC.               
 
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...            

THE MONSOON TROUGH AXIS WAS ANALYZED FROM 05N77W TO 07N86W TO
06N92W TO LOW PRESSURE NEAR 06.5N97W 1009 MB TO 08N110W...THEN
CONTINUES FROM LOW PRESSURE NEAR 12N114W 1010 MB TO 05N126W TO
05N135W TO 03N140W. SCATTERED MODERATE CONVECTION WAS WITHIN 45
NM N AND 75 NM S OF THE AXIS BETWEEN 78W-81W. SCATTERED MODERATE
TO STRONG CONVECTION WAS BETWEEN 90 NM AND 270 NM N OF THE AXIS
BETWEEN 102W-108W...WITH SCATTERED MODERATE CONVECTION ELSEWHERE
WITHIN 180 NM EITHER SIDE OF THE AXIS BETWEEN 103W-110W.
SCATTERED MODERATE CONVECTION WAS WITHIN 240 NM S OF THE AXIS
BETWEEN 114W-125W AS WELL AS WITHIN 180 NM N OF THE AXIS W OF
125W.

...DISCUSSION...

AN UPPER LOW REMAINS CUT OFF WEST OF CLARION ISLAND NEAR
18N119W. UPPER LEVEL DIFFLUENCE IN THE EXIT REGION OF THE JET ON
THE E SIDE OF THE LOW IS SUPPORTING AREAS OF SHOWERS ACROSS THE
REVILLAGIGEDO ISLANDS. AN ASSOCIATED 1010 MB LOW PRESSURE SYSTEM
WAS NEAR 12N114W...WITH SCATTERED MODERATE CONVECTION WITHIN 330
NM NE QUADRANT. GLOBAL MODELS INDICATE THAT THIS LOW WILL MOVE N-
NE TOWARD MANZANILLO MEXICO THROUGH THE NEXT COUPLE OF
DAYS...BUT WEAKEN AS THE UPPER LOW IS PHASES WITH THE
SUBTROPICAL JET SAT. ASCAT PASSES FROM AROUND 1700-1800 UTC
SHOWED 20-25 KT WITHIN 150 NM IN THE N AND NE QUADRANTS OF THE
SURFACE LOW. THESE WINDS ARE FORECAST TO DIMINISH BELOW 20-25 KT
SAT AFTERNOON. 

A COLD FRONT WAS ANALYZED THROUGH THE GULF OF CALIFORNIA AND THE
BAJA CALIFORNIA PENINSULA FROM 30N112W TO 25N120W TO 22N140W. IT
WILL WEAKEN AS IT REACHES THE SOUTHERN GULF AND SOUTHERN BAJA
CALIFORNIA SUR SAT BEFORE BECOMING DIFFUSE. IN THE
PACIFIC...FRESH TO STRONG WINDS ARE BEHIND THE FRONT N OF 28N E
OF 124W. LONGER PERIOD NW SWELL IS ACCOMPANYING THE FRONT...WITH
SEAS IN THE 12 TO 18 FT RANGE OFF THE COAST OF BAJA CALIFORNIA
NORTE. INTERESTS PRIMARILY ALONG THE BAJA CALIFORNIA COAST AND
NEARBY ISLANDS SHOULD TAKE CAUTION. THE LEADING EDGE OF THIS
SWELL...WITH PERIODS IN THE 18-20 SECONDS RANGE...WILL REACH THE
SOUTHERN TIP OF THE BAJA CALIFORNIA PENINSULA EARLY SAT AND CABO
CORRIENTES MEXICO BY SAT EVENING.

THE SUBTROPICAL RIDGE IS STRENGTHENING OVER N WATERS BEHIND THE
COLD FRONT. FRESH TO STRONG NE WINDS WERE NOTED BY RECENT
SCATTEROMETER PASSES BOTH AHEAD OF THE FRONT FROM 13N-20N W OF
137W AND N OF THE MONSOON TROUGH FROM 08N-10N BETWEEN 129W AND
136W. THESE WINDS ARE EXPECTED TO EXPAND OVER MUCH OF THE AREA
FROM 11N-21N W OF 122W THROUGH SAT AS HIGH PRESSURE CONTINUES TO
BUILD. THE HIGH PRESSURE CENTER N OF THE AREA IS FORECAST TO
WEAKEN SUN AS A NEW COLD FRONT ENCROACHES UPON IT FROM THE N.
THE AREA OF TRADE WINDS SHOULD SHRINK TO W OF 130W AS A RESULT.

GAP WINDS...

GULF OF PAPAGAYO...A SURFACE RIDGE OVER THE GULF OF MEXICO WILL
STRENGTHEN OVERNIGHT. THIS WILL INCREASE THE PRESSURE GRADIENT
BETWEEN THE RIDGE AND THE MONSOON TROUGH TO THE S OF THE GULF OF
PAPAGAYO. THE INCREASED PRESSURE GRADIENT COUPLED WITH NOCTURNAL
DRAINAGE FLOW SHOULD ALLOW FOR A FRESH TO STRONG E-NE BREEZE
THROUGH THE GULF OF PAPAGAYO TO 88W DURING THE EARLY MORNING
HOURS SAT. THESE WINDS ARE FORECAST TO DIMINISH AFTER SUNRISE
SAT AS THE DRIVING HIGH PRES SHIFTS NE INTO THE ATLC.

GULF OF CALIFORNIA...AS MENTIONED IN THE DISCUSSION SESSION
ABOVE...A COLD FRONT IS MOVING THROUGH THE GULF OF CALIFORNIA.
IT IS USHERING IN A FRESH TO STRONG BREEZE PRIMARILY FROM THE NW.
THESE WINDS ARE CURRENTLY CONFINED TO THE FAR NORTHERN GULF OF
CALIFORNIA BEHIND THE FRONT...BUT SHOULD QUICKLY SPREAD AS FAR S
AS 27N OVERNIGHT. WINDS FUNNELING THROUGH MOUNTAIN PASSES MAY BE
CLOSE TO GALE FORCE. THESE WINDS ARE EXPECTED TO DIMINISH BELOW
A FRESH TO STRONG BREEZE FROM N TO S THROUGH SAT AFTERNOON AS
THE FRONT WEAKENS.

$$
SCHAUER