000
AXPZ20 KNHC 260954
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC MON MAR 26 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 ALONG 4N78W 4N105W 5N130W 4N140W. ISOLATED MODERATE 
CONVECTION AND LIGHTNING DETECTED WITHIN 15 NM OF LINE 8N83W 
4N90W 6N96W 4N104W 6N110W. SCATTERED MODERATE ISOLATED STRONG 
CONVECTION AND LIGHTNING IS INDICATED FROM 4N TO 11N BETWEEN 
124W AND 137W.

...DISCUSSION...

AN UNSTABLE UPPER RIDGE HAS COLLAPSED OVER THE NW PORTION OF THE 
DISCUSSION AREA WITH ITS AXIS ALONG 24N142W 30N117W. UPPER 
MOISTURE LIES UNDER THE RIDGE OVER THE AREA N OF 24N W OF 117W. 
A MID TO UPPER TROUGH OVER THE CENTRAL CONUS EXTENDS SW THROUGH 
A DEEP LAYERED CYCLONE OVER OLD MEXICO...NEAR 28N108W...INTO THE 
E PAC ALONG 23N109W 16N120W 13N130W 14N140W. DRY UPPER AIR 
ACCOMPANIES THIS UPPER TROUGH ROUGHLY WITHIN 300 NM EITHER SIDE 
OF LINE 27N108W 20N121W 17N135W 22N145W. 

AN UPPER LEVEL ANTICYCLONE IS AT 9N104W WITH A RIDGE EXTENDING W 
TO A SHARP CREST AT 7N117W. A MORE DOMINATE...LONGWAVE...UPPER 
RIDGE EXTENDS N ACROSS CENTRAL OLD MEXICO AND ACROSS EASTERN N 
AMERICA. ANOTHER TROPICAL UPPER ANTICYCLONE IS ESTIMATED NEAR 
2N135W WITH A SHORT RIDGE TO NEAR 6N127W. AN INVERTED UPPER 
TROUGH EXTENDS N ACROSS THE EQUATOR TO NEAR 6N120W...AND  
EFFECTIVELY SEPARATES THE ANTICYCLONIC FLOW DESCRIBED ABOVE. THE 
RESULT IS BROAD UPPER DIFFLUENCE ENHANCING CONVECTION ALONG THE 
N HEMISPHERIC ITCZ BETWEEN 119W AND 142W. THE RESULTANT UPPER 
DEBRIS MOISTURE BECOMES CONCENTRATED IN A 420 NM WIDE BAND 
CENTERED ALONG 10N117W 19N105W TO BEYOND 30N97W. THIS MOISTURE 
FANS OUT OVER THE UPPER LEVELS OF THE SE CONUS WITH SOME OF THE  
MOISTURE SPILLING BACK SE OVER THE GULF OF MEXICO. 

AN UPPER TROUGH OVER THE CARIBBEAN CONTINUES SW INTO THE E PAC 
TO NEAR 3N82W. WEAK UPPER DIFFLUENCE E OF THE ANTICYCLONE AT 
9N104W IS ENHANCING ISOLATED TSTMS E OF 110W...DESCRIBED ABOVE. 
THE UPPER LEVELS ARE DRY E OF 100W. 

THE UPPER CYCLONE OF NORTHERN OLD MEXICO HAS SURFACE REFLECTIONS 
NEAR 31N104W AND 26N104W. HIGH PRES NEAR 31N135W WILL BRIEFLY 
DISSIPATE AS A WEAK COLD FRONT APPROACHES...CURRENTLY ALONG 
34N137W 30N144W. EXPECT HIGH PRES TO BRIDGE ANY REMNANTS OF 
FRONT LATE TODAY WITH RIDGE ALONG 30N135W 15N105W. BELIEVE FRONT 
SO WEAK THAT DROPPED MENTION IN TEXT HIGH SEAS. I DESCRIBE WIND 
SHIFT EITHER SIDE OF RIDGE WITH GRADIENT INCREASING EASTWARD TO 
BAJA PENINSULA BY 36 HOURS. GRADIENT WILL INCREASE NW WINDS TO 
20 KT OVER SEA OF CORTEZ BY 48 HOURS. NW SWELLS WILL PROPAGATE 
SE THROUGH INCREASING NE LOW LEVEL FLOW AROUND RIDGE.    

GAP WINDS...N WINDS CONTINUE TO SURGE AROUND 20 KT OVER AND JUST 
S OF THE GULF OF TEHUANTEPEC. HI RESOLUTION MODELS SUGGEST NLY 
FLOW WILL DIMINISH BELOW 20 KT BETWEEN 00 AND 09Z DAILY...THEN 
INCREASE TO 20 KT...AND OCCASIONALLY 25 KT...AROUND 14Z DAILY. 
GRADIENT IN SW CARIBBEAN IS SUPPORTING NE 15 KT. EXPECT NE WINDS 
INTO GULF OF PAPAGAYO TO DIMINISH TO LESS THAN 20 KT LATER TODAY.

$$
NELSON