000
AXPZ20 KNHC 230923
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC FRI DEC 23 2011

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.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
THE MONSOON TROUGH AXIS EXTENDS FROM 10N85W TO 07N93W. THE ITCZ 
AXIS EXTENDS FROM 07N93W TO 09N119W WHERE THERE IS A BREAK IN 
THE ITCZ DUE TO A SURFACE TROUGH FROM 14N118W TO 08N121W. THE 
ITCZ THEN CONTINUES FROM 09N122W AND EXTENDS TO BEYOND 08N140W. 
SCATTERED MODERATE CONVECTION WAS NOTED WITHIN 45 NM OF AXIS W 
OF 125W. 

...DISCUSSION...

GULF OF CALIFORNIA...STRONG DEEP LAYER RIDGING IS BUILDING OVER 
THE GREAT BASIN...N OF A CUT OFF UPPER LOW MOVING SLOWLY E 
THROUGH ARIZONA. THIS IS PROMOTING STRONG NORTHERLY FLOW DOWN 
THE LENGTH OF THE GULF OF CALIFORNIA. A 0412 UTC ASCAT PASS 
INDICATED 30 KT FLOW OVER THE NORTHERN GULF OF CALIFORNIA. WINDS 
TO GALE FORCE ARE LIKELY STARTING OVER THE NORTHERN GULF. IN 
ADDITION...THE STRONG GRADIENT FLOW ACROSS THE GULF OF 
CALIFORNIA WILL SPILL OVER SOME OF THE GAPS ON THE BAJA 
PENINSULA...WITH CERTAIN AREAS OF WINDS TO 30 KT ALONG THE 
PACIFIC COAST OF BAJA THROUGH FRI. THE RIDGING OVER THE GREAT 
BASIN WILL WEAKEN SLIGHTLY AS A SHORT WAVE TROUGH MIGRATES N OF 
THE RIDGE THROUGH THE NORTHERN ROCKIES...ALLOWING WINDS OVER THE 
GULF OF CALIFORNIA TO START TO DIMINISH BY SAT. 

GULF OF TEHUANTEPEC...COLD AIR MOVING THROUGH THE GULF OF MEXICO 
WILL PUSH THROUGH THE CHIVELA PASS ARE STARTING TO PUSH INTO 
OVER THE GULF OF TEHUANTEPEC. A 0408 UTC PASS SHOWED 20 KT N 
FLOW IN THE GULF OF TEHUANTEPEC. WINDS ARE FORECAST TO REACH 
GALE FORCE OVERNIGHT FRI NIGHT INTO SAT AS HIGH PRES BEGINS TO 
EMERGE IN THE SOUTHERN PLAINS...WHICH WILL INCREASE THE WINDS 
FUNNELING INTO THE GULF OF TEHUANTEPEC. THIS WILL DIMINISH 
SLIGHTLY THROUGH SAT AS THE COLD HIGH PRES TO THE NORTH WEAKENS 
AND MODIFIES. WINDS WILL INCREASE AGAIN SUN...POSSIBLY TO GALE 
FORCE...AS ANOTHER SURGE OF COLD AIR MOVES THROUGH THE WESTERN 
GULF OF MEXICO AND INTO THE TEHUANTEPEC AREA. 

GULF OF PAPAGAYO...FRESH TRADEWINDS OVER THE WESTERN CARIBBEAN 
WILL FUNNEL INTO THE GULF OF PAPAGAYO. WINDS WILL PEAK DURING 
THE EARLY MORNING HOURS WITH THE ADDITION OF NOCTURNALLY DRIVEN 
KATABATIC WINDS.

ELSEWHERE W OF 110W...A 06 UTC ASCAT PASS SHOWED A BROAD SWATH 
OF 20 KT NE TRADE WINDS GENERALLY FROM 12N TO 23N W OF 115W...S 
OF A 1030 MB SURFACE HIGH PRES CENTERED NEAR 40N130W. A WEAK 
SURFACE TROUGH FROM 14N118W TO 08N121W IS DRIFTING W ALONG THE 
ITCZ. ALTIMETER PASSES OVER THE PAST 12 HOURS INDICATE SEAS TO 9 
FT IN THE AREA OF FRESH TRADE WINDS...PRIMARILY IN MIXED NW AND 
NE SWELL. THE UPPER PATTERN WILL BECOME MORE AMPLIFIED OVER THE 
NEXT 24 TO 48 HOURS...ALLOWING THE HIGH PRES N OF THE AREA TO 
BUILD. AS A RESULT TRADE WIND FLOW WILL INCREASE SLIGHTLY THIS 
WEEKEND WITH MIXED SEAS BUILDING TO 12 FT. MEANWHILE...TRADE 
WIND CONVERGENCE AT THE SURFACE ALONG WITH UPPER LEVEL DIVERGENT 
FLOW IS SUPPORTING SCATTERED CONVECTION ALONG THE ITCZ W OF 125W.

$$
CHRISTENSEN