Subject: Pacific-EN: Tropical Weather Discussion

From: SIU Weather Processor <[email-masked]>
Date: Tue, 15 Feb 2005 10:03:50 -0600

AXPZ20 KNHC 151603
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC TUE FEB 15 2005

TROPICAL WEATHER DISCUSSION FOR EASTERN PACIFIC OCEAN FROM 
EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS 
BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...
AND METEOROLOGICAL ANALYSIS.

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1545 UTC.

..ITCZ...
INTERTROPICAL CONVERGENCE ZONE...AXIS 3N77W 6N96W 2N102W 5N123W 
9N130W 6N140W. SCATTERED MODERATE WITHIN 60 NM EITHER SIDE OF 
AXIS BETWEEN 92W AND 107W.

DISCUSSION...
AN UPPER ANTICYCLONE IS ESTIMATED NEAR 6N153W WITH A LOW 
AMPLITUDE SHORTWAVE RIDGE EXTENDING NE ACROSS THE ITCZ CRESTING 
IN THE DISCUSSION ALONG 11N140W 2N120W. A LARGE MID TO UPPER 
ANTICYCLONE ESTIMATED NEAR 14N110W WITH ITS ENVELOPE OF 
ANTICYCLONIC FLOW DOMINATING THE DISCUSSION AREA N OF THE ITCZ 
BETWEEN 115W AND 95W. IMMEDIATELY TO THE SW AN UPPER CYCLONE IS 
ESTIMATED NEAR 7N116W BUT APPEARS TO BE DISSIPATING. AN UPPER 
TROUGH LIES ALONG 1N103W TO 16N94W SEPARATING THIS ANTICYCLONE 
FROM ANOTHER ESTIMATED NEAR 4N73W WITH ANTICYCLONIC FLOW SE OF 
LINE 4N88W 18N86W 22N75W. UPPER DIFFLUENCE NEAR THE TROUGH IS 
ENHANCING ITCZ CONVECTION BETWEEN 92W AND 107W.

ALTHOUGH THE E PORTION OF THE N PACIFIC BASIN IS UNDER A 
LONGWAVE RIDGE..AN EMBEDDED MID TO UPPER CYCLONE IS STATIONARY 
NEAR 35N133W. AN UPPER TROUGH EXTENDS SW FROM THE CYCLONE ALONG 
28N130W 22N137W. A RE-INFORCING SHORTWAVE TROUGH IS MOVING 
RAPIDLY SE INTO THE SW QUADRANT OF THE MID TO UPPER CYCLONE. AT 
THE SURFACE...A LOW IS CENTERED AT 35N130W 1000 MB WITH A COLD 
FRONT SW ALONG 32N124W TO 20N130W...THEN DIFFUSE TO 14N140W. 
BROKEN TO OVERCAST MULTILAYERED CLOUDS OBSERVED N OF 23N WITHIN 
90 NM E OF THE FRONT. SEVERAL SECONDARY SURGES ARE ROTATING 
AROUND THE THE CYCLONE ACCOMPANIED BY SW TO NW WIND SHIFTS. ONE 
ONE THESE SURGES IS ANALYZED ALONG 32N127W 26N136W AND 
ACCOMPANIED BY BROKEN TO LOCALLY OVERCAST STRATOCUMULUS.

A WESTERLY UPPER WIND MAXIMA...ABOUT 600 NM WIDE...HAS AXIS FROM 
12N140W TO NEAR 12N134W WHERE THE UPPER FLOW SPLITS. ONE BRANCH 
TURNS CYCLONICALLY NE ALONG THE EAST EDGE OF THE UPPER TROUGH 
AND ALONG THE NW PERIPHERY OF THE RIDGE SPLITTING AGAIN NEAR 
30N122W. MODERATE MOISTURE NOTED ALONG THIS SEGMENT OF JET WITH 
STRONG DRYING NOTED NW OF THE THE UPPER TROUGH. THE OTHER BRANCH 
OF THE SOUTHERN SPLIT OF THE WESTERLY JET CONTINUES SE INTO THE 
UPPER CYCLONE AT 7N116W AND LOSES IDENTITY AS THE UPPER LEVEL 
MOISTURE TRACERS DISSIPATE.

N WINDS TO 20 KT IN THE GULF OF TEHUANTEPEC AT SUNRISE THIS 
MORNING ATTRIBUTED TO DRAINAGE AND NOT EXPECTED TO CONTINUE PAST 
MORNING HEATING. NE 15 KT WINDS ALSO DETECTED ON QSCAT IN THE 
GULF OF PAPAGAYO AND W PORTION OF GULF OF PANAMA. SIMILAR LATE 
NIGHT WINDS POSSIBLE NEXT FEW DAYS. NW TO N 20 KT WINDS ALONG SW 
COAST OF BAJA PENINSULA SHOULD DISSIPATE SOON AS HIGH PRES NEAR 
26N118W SHIFTS E.   

$$
NELSON

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