000
AXPZ20 KNHC 250943
TWDEP 

TROPICAL WEATHER DISCUSSION     
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC THU JAN 25 2007

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 
0945 UTC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG AXIS 5N77W 7N86W 6N100W 10N107W 
4N122W 4N140W. SCATTERED MODERATE WITHIN 90 NM OF AXIS ALONG THE 
COLOMBIAN COAST. SCATTERED MODERATE ISOLATED STRONG WITHIN 120 
NM OF THE AXIS BETWEEN 82W AND 91W.

...DISCUSSION...

REX BLOCK PATTERN PERSISTS OVER THE ROCKIES AND NW MEXICO AS 
CLOSED UPPER LOW CENTERED OVER NW MEXICO NEAR 28N110W SLOWLY 
RETROGRADES TO THE W...S OF A HIGHLY AMPLIFIED RIDGE OVER THE 
WRN STATES. TRAILING UPPER TROUGH EXTENDS FROM THE UPPER LOW TO 
12N140W. SOUTHERN JET STREAM S OF THE TROUGH WITH MAX SWLY WINDS 
100-120 KT...IS TRANSPORTING COPIOUS MID AND UPPER LEVEL PACIFIC 
MOISTURE ACROSS CENTRAL MEXICO AND INTO THE SE U.S. MEANWHILE A 
VIGOROUS UPPER LOW NEAR 38N130W IS DIGGING EWD TOWARD THE NRN 
COAST OF CALIFORNIA. SHORT WAVE ENERGY ON THE W SIDE OF THIS 
FEATURE IS PROMOTING A SURFACE COLD FRONT EXTENDING FROM 30N132W 
TO 26N140W...W OF A 1025 MB SURFACE HIGH PRES CELL CENTERED 
NEAR 29N1127W. SATELLITE IMAGERY SHOWS DEEP LAYER OFFSHORE FLOW 
IS KEEPING PACIFIC WATERS GENERALLY CLOUD FREE FOR ALMOST 500 NM 
OFF THE BAJA COAST. FURTHER W...REMNANT PATCHES OF STRATOCUMULUS 
PERSIST S OF THE HIGH. THE UPPER LOW OFF THE CALIFORNIA COAST 
WILL SERVE TO WEAKEN THE UPPER RIDGE TO THE E OVER THE NEXT 
COUPLE OF DAYS...ALLOWING THE UPPER LOW OVER NW MEXICO TO OPEN 
UP AND LIFT OUT TO THE NE. AS THIS HAPPENS...THE FRONTAL 
BOUNDARY WILL LOSE UPPER SUPPORT OVER THE NEXT 48 HOURS THEN 
STALL AND DISSIPATE. FRESH TRADE WIND FLOW WILL PERSIST S OF THE 
RIDGE. EXPECT LARGE SWELL TO PUSH INTO THE AREA FROM THE NW 
BEHIND THE DECAYING FRONT.

FURTHER E...EVENING QUIKSCAT PASS SHOWED FRESH NWLY FLOW 
CONTINUES IN GULF OF CALIFORNIA. THIS WILL WEAKEN OVER THE NEXT 
COUPLE OF DAYS AS HIGH PRES BUILDS OVER THE AREA. UPPER RIDGE 
EXTENDS ROUGHLY ALONG 13N FROM THE CARIBBEAN THROUGH CENTRAL 
AMERICA AND INTO THE PACIFIC TO AROUND 110W. QUIKSCAT SHOWED 
POSITION OF STATIONARY TROUGH EXTENDING FROM 7N112W TO 
16N103W...LIKELY ENHANCED BY UPPER DIVERGENCE BETWEEN THE 
SUBTROPICAL JET AND THE WESTERN EDGE OF THE UPPER RIDGE. 
DIVERGENCE ALOFT WAS ALSO ENHANCING MODERATE TO STRONG 
CONVECTION ALONG THE ITCZ AS DESCRIBED ABOVE. 

GULF OF TEHUANTEPEC...SURFACE PRES VALUES OVER S TEXAS AND THE E 
COAST OF MEXICO ARE INDICATIVE OF NEAR GALE CONDITIONS IN GULF 
OF TEHUANTEPEC. SURFACE OBSERVATIONS IN THE ISTHMUS SHOW 
SUSTAINED WINDS NEAR 20 KT WITH GUSTS TO 30 KT...PRESUMED TO BE 
MIXING TO THE SURFACE OVER GULF OF TEHUANTEPEC. EXPECT GALE 
CONDITIONS TO START THIS MORNING...AND PERSIST THROUGH THU.

GULF OF PAPAGAYO...FRESH ELY WINDS OVER CARIBBEAN WILL FILTER 
INTO GULF OF PAPAGAYO THROUGH AT LEAST NEXT COUPLE OF DAYS.

GULF OF PANAMA...LATEST QUIKSCAT PASS SHOWS NLY FLOW DIMINISHING.

$$
CHRISTENSEN