000
AXPZ20 KNHC 100352
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC SUN OCT 10 2010

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN
FROM THE EQUATOR TO 32N...EAST OF 140W.

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0315 UTC.

...THE ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE IS ANALYZED FROM 09N84W TO 
07N90W TO  08N118W TO 11N128W TO 09N140W. SCATTERED MODERATE TO 
ISOLATED STRONG CONVECTION NOTED WITHIN 60 NM OF AXIS 125W.

...DISCUSSION...

E OF 110W...
LATEST OBSERVATIONS FROM SALINA CRUZ ON THE SOUTH END OF THE 
ISTHMUS OF TEHUANTEPEC SHOW THAT FRESH TO STRONG GAP WIND FLOW 
CONTINUES THROUGH INTO GULF OF TEHUANTEPEC THIS EVENING. THIS 
FLOW LIKELY PERSISTS DUE TO 1022 MB HIGH PRES CENTERED OVER EAST 
CENTRAL COAST OF MEXICO. THE HIGH PRES WILL WEAKEN THROUGH 
MIDDAY SUN...ALLOWING THE GAP WIND FLOW TO DIMINISH. 
MEANWHILE...AN UPPER LEVEL RIDGE EXTENDS FROM ABOVE NICARAGUA 
WESTWARD TO NEAR 18N115W. SHARP DIFLUENCE ALOFT IS ALLOWING 
MODEST SHOWER ACTIVITY ALONG THE MEXICAN COAST NEAR MANZANILLO. 
FURTHER SOUTH...DIVERGENT FLOW ALOFT BETWEEN THE UPPER RIDGE AND 
AN UPPER LOW NEAR 06N105W IS ENHANCING A FEW SHOWERS ALONG THE 
ITCZ BETWEEN 85W AND 95W. S OF THE ITCZ...SW SWELL WITH HEIGHTS 
TO 9 FT AND PERIODS TO 16S CONTINUES TO MOVE ACROSS THE EQUATOR.

W OF 110W...
AN UPPER RIDGE CENTERED NEAR 34N128W IS BECOMING MORE AMPLIFIED 
BETWEEN A BROAD LONG WAVE TROUGH APPROACHING FROM THE N CENTRAL 
PACIFIC...AND A DEEP LAYER LOW OVER THE CENTRAL PLAINS...WITH 
SHARP ELONGATED UPPER TROUGH EXTENDING SW TO NEAR 21N144W. AN 
ASSOCIATED 1027 MB SURFACE HIGH PRES IS CENTERED NEAR 31N131W. 
CURRENT SHIP OBSERVATIONS ALONG THE BAJA COAST SHOW NW TO N 
WINDS HAVE INCREASED TO 20 KT BETWEEN THE HIGH PRES AND THE 
COAST. AN ASCAT PASS FROM EARLIER TODAY ALSO SHOWED 20 KT NW 
FLOW IN THE GULF OF CALIFORNIA. JET ENERGY BETWEEN THE UPPER 
RIDGE AND THE DEEP LAYER LOW OVER THE PLAINS WILL DIG S THROUGH 
THE ROCKIES INTO THE TROUGH...CUTTING OFF AN UPPER LOW S OF THE 
UPPER RIDGE NEAR 25N125W. THIS WILL SET UP A REX BLOCK PATTERN 
THAT WILL IMPEDE THE EASTWARD PROGRESS OF THE APPROACHING LONG 
WAVE TROUGH. THE NET EFFECT AT THE SURFACE OF ALL THIS IS THAT 
THE SURFACE HIGH WILL SHIFT W AND ALLOW THE WINDS OFF BAJA AND 
THE GULF OF CALIFORNIA TO DIMINISH THROUGH EARLY SUN. IN 
ADDITION A SURFACE FRONT ASSOCIATED WITH THE APPROACHING UPPER 
TROUGH WILL STALL N OF THE AREA BY LATE SUN. A 1033 MB SURFACE 
HIGH PRES BEHIND THE FRONT WILL SHIFT EAST THROUGH MIDDAY SUN 
THEN STALL. TRADE WIND FLOW ALONG THE SOUTHERN PERIPHERY OF THE 
HIGH PRES WILL INCREASE IN COVERAGE W OF 120W SUN INTO 
MON...THEN DIMINISH HAS THE HIGH PRES TO THE NORTH WEAKENS 
STARING LATE MON. 
  
$$

CHRISTENSEN