000
AXPZ20 KNHC 021507
TWDEP 

TROPICAL WEATHER DISCUSSION                                    
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
1605 UTC FRI JAN 02 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 
1500 UTC. 

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
             
THE MONSOON TROUGH EXTENDS FROM 07N77W TO 05N83W TO 06N85W TO 
05N95W TO 05N100W...WHERE IT TRANSITIONS TO THE ITCZ. THE ITCZ 
CONTINUES FROM 05N100W TO 06N110W TO 05N125W TO 06N135W TO WEST 
OF 05N140W. SCATTERED MODERATE CONVECTION IS NOTED WITHIN 90 NM 
EITHER SIDE OF THE ITCZ AXIS BETWEEN 110W AND 120W.

...DISCUSSION...                                                 

AN UPPER TROUGH MOVING ACROSS THE BAJA CALIFORNIA PENINSULA AND 
THE NORTHERN GULF OF CALIFORNIA WILL LIFT NE OF THE AREA TODAY 
AND TONIGHT. THE TROUGH HAS BEEN SUPPORTING A FRONTAL BOUNDARY 
MOVING DOWN THE BAJA CALIFORNIA PENINSULA AND GULF OF CALIFORNIA 
OVER THE PAST COUPLE OF DAYS. THIS APPEARS TO BE STALLING AND 
WEAKENING...AND WILL BECOME DIFFUSE OVERNIGHT AS THE UPPER 
SUPPORT LIFTS OUT. 

FOR THE GULF OF CALIFORNIA...HIGH PRES OVER THE EASTERN PACIFIC 
BUILDING BEHIND THE FRONT WAS ENHANCING NW FLOW DOWN THE LENGTH 
OF THE GULF OF CALIFORNIA...AND THESE WINDS WILL DIMINISH AS THE 
FRONT CONTINUES TO WEAKEN. THIS RESPITE MAY BE BRIEF HOWEVER AS 
HIGH PRES BUILDS OVER THE GREAT BASIN N OF THE AREA THIS 
WEEKEND...INDUCING FRESH TO STRONG NW FLOW INTO THE GULF OF 
CALIFORNIA BY LATE SUNDAY INTO MONDAY.

NW OF THE AREA A FRONT EXTENDS FROM A 991 MB OCCLUDED LOW PRES 
AREA CENTERED NEAR 35N155W TO 37N145W TO 30N143W TO 20N148W. THE 
LOW CENTER AND ACCOMPANYING FRONT WILL MOVE EASTWARD INTO AN 
ELONGATED RIDGE PARALLELING THE WEST COAST OF THE UNITED STATES 
OVER THE NEXT COUPLE OF DAYS. THIS WILL BRING FRESH TO STRONG SE 
WINDS INTO THE DISCUSSION AREA N OF 20N W OF 135W BY LATE 
SAT...WITH SEAS 8 TO 10 FT IN A MIX OF LONGER PERIOD NW SWELL 
AND SE WIND WAVES. LIFT ASSOCIATED WITH THE SUPPORTING UPPER 
TROUGH WILL PRODUCE AREAS OF SHOWERS AND THUNDERSTORMS IN THIS 
AREA AS WELL SAT AND SUN.

THE EASTWARD MOVEMENT OF THE LOW PRES HAS DISPLACED THE 
SUBTROPICAL RIDGE FARTHER NORTH...WHICH IN TURN IS ALLOWING ONLY 
MODERATE TO FRESH TRADE WIND FLOW IN THE DEEP TROPICS W OF 120W. 
ALTIMETER SATELLITE DATA OVER THE PAST SEVERAL HOURS INDICATED 
SEAS TO 8 FT IN THE TRADE WIND BELT...WHICH WILL LARGELY 
PERSIST THROUGH THE WEEKEND.

BUOY OBSERVATIONS ALONG WITH AN ASCAT SATELLITE PASS FROM 00 UTC 
YESTERDAY EVENING INDICATED A PERSISTENT SURFACE TROUGH ALONG 
THE ITCZ NEAR 110W...AND ARTIFACT OF AN UPPER TROUGH THAT 
RECENTLY LIFTED OUT OF THE AREA. THE SURFACE TROUGH IS ENHANCING 
TRADE WIND CONVERGENCE AND SUPPORTING RAIN SHOWERS ALONG THE 
ITCZ BETWEEN 110W AND 120W. THE TROUGH IS EXPECTED TO PERSIST 
OVER THE NEXT 48 TO 72 HOURS AS IT DRIFTS WEST ALONG THE ITCZ.

GULF OF PAPAGAYO...HIGH PRES N OF THE SW CARIBBEAN ALONG WITH 
LOCAL OVERNIGHT DRAINAGE EFFECTS WILL SUPPORT PULSES OF FRESH TO 
STRONG GAP WINDS WITH SEAS TO 10 FT THROUGH MON MORNING.

GULF OF TEHUANTEPEC...WINDS ARE GRADUALLY DIMINISHING WITH SEAS 
LESS THAN 8 FT. LOOKING AHEAD...A STRONG COLD FRONT IN THE GULF 
OF MEXICO WILL USHER ANOTHER ROUND OF GAP WINDS INTO THE GULF OF 
TEHUANTEPEC BY SUNDAY...REACHING GALE FORCE BY SUNDAY NIGHT. 
GLOBAL AND REGIONAL MODELS HINT THAT THIS WILL BE A STRONG GALE 
OR EVEN PUSHING STORM CRITERIA...DUE TO THE COLD DENSE AIR 
EXPECTED TO FUNNEL THROUGH THE WESTERN GULF OF MEXICO AND ACROSS 
THE TEHUANTEPEC ISTHMUS LATE SUN. THE CURRENT OFFICIAL FORECAST 
HAS 45 KT GAP WINDS WITH SEAS BUILDING TO 21 FT DOWNSTREAM OF 
THE GULF OF TEHUANTEPEC BY EARLY MONDAY.
 
$$
CHRISTENSEN