Sample East Pacific Tropical Weather Discussion

AXPZ20 KNHC 090941
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 
1005 UTC SAT 09 AUG XXXX

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

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY 
THROUGH 0915 UTC.

...SPECIAL FEATURES...

TROPICAL STORM GUILLERMO CENTERED NEAR 16.0N 121.5W AT 09/0900 UTC 
MOVING W AT 10 KT. MAXIMUM SUSTAINED WIND SPEED IS 50 KT WITH GUSTS TO 
60 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 997 MB. SEE LATEST NHC 
FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP2/WTPZ22 KNHC FOR 
MORE DETAILS. GUILLERMO HAS EXPERIENCED LITTLE CHANGE OVER THE PAST SIX 
HRS. IT CONTINUES TO HAVE A CONSOLIDATED CLUSTER OF CONVECTION WHICH IS 
OFFSET PRIMARILY TO THE SW OF THE LOW-LEVEL CENTER. SHEAR OVER THE 
SYSTEM IS WEAK BUT THE UPPER LEVEL OUTFLOW DOES NOT EXTEND VERY FAR 
AWAY FROM THE STORM. NUMEROUS MODERATE/ISOLATED STRONG CONVECTION FROM 
14N-17N BETWEEN 120.5W-123W.

TROPICAL DEPRESSION EIGHT-E CENTERED NEAR 13.0N 111.6W AT 09/0900 UTC 
MOVING W AT 12 KT. MAXIMUM SUSTAINED WIND SPEED IS 25 KT WITH GUSTS TO 
35 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1007 MB. SEE LATEST NHC 
FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP3/WTPZ23 KNHC FOR 
MORE DETAILS. T.D. EIGHT-E IS ORGANIZING QUICKLY. THE SYSTEM LOOKS 
ALMOST BETTER THAN GUILLERMO WITH MORE PRONOUNCED BANDING FEATURES AND 
EXCELLENT UPPER LEVEL OUTFLOW ESPECIALLY OVER THE S SEMICIRCLE. IT IS 
EMBEDDED WITHIN A LARGE AREA OF MOISTURE SO DRY AIR IS CURRENTLY NOT AN 
ISSUE. NUMEROUS MODERATE/ISOLATED STRONG CONVECTION FROM 11.5N-15.5N 
BETWEEN 110W-114W. SCATTERED MODERATE FROM 8N-11.5N BETWEEN 109W-115W.

...TROPICAL WAVES...

TROPICAL WAVE ALONG 82W N OF 5N MOVING W 10 KT. SEE ITCZ FOR RELATED 
CONVECTION.

TROPICAL WAVE ALONG 94W S OF 17N MOVING W 10 KT. NUMEROUS MODERATE 
CONVECTION OVER THE GULF OF TEHAUNTEPEC FROM 14.5N-17N BETWEEN 93.5W-
96.5W. WIDELY SCATTERED MODERATE FROM 9N-16N BETWEEN 96W-99W.

TROPICAL WAVE ALONG 137W S OF 18N MOVING W 10-15 KT. SEE ITCZ FOR 
RELATED CONVECTION.

...ITCZ...

AXIS OF ITCZ-RELATED CLOUDS/CONVECTION IS CENTERED ALONG 6N75W 6N84W 
7N98W 10N110W 10N124W 13N129W 10N140W. WIDELY SCATTERED MODERATE 
CONVECTION WITHIN 30 NM OF THE AXIS BETWEEN 91W-100W. WIDELY SCATTERED 
MODERATE WITHIN 30 NM OF THE AXIS BETWEEN 124W-127W. SCATTERED MODERATE 
WITHIN 90 NM OF THE AXIS BETWEEN 130W-138W.

...DISCUSSION...

WEST OF 130W...
A WEAKENING LONGWAVE UPPER LEVEL TROUGH LOCATED JUST NORTH OF THE 
HAWAIIAN ISLANDS IS PUSHING EWD TOWARDS THE AREA AND IS ASSOCIATED WITH 
A DISSIPATING SURFACE COLD FRONT NOW ALONG 32N131W 30N140W. ALL 
CONVECTION HAS DISSIPATED ALONG THE FRONT ALTHOUGH A 45NM-WIDE BAND OF 
LOW/MID LEVEL CLOUDINESS EXTENDS WEST OF THE BOUNDARY.

BETWEEN 110W AND 130W...
A WEAK SUBTROPICAL SURFACE RIDGE EXTENDS ALONG 30N132W 26N118W 20N110W 
WITH ITS WRN EXTENT BEING ERODED BY THE COLD FRONT APPROACHING FROM THE 
WEST. STRONG DEEP-LAYERED RIDGING EXTENDS ACROSS THE ENTIRE AREA WITH A 
STRONG UPPER LEVEL ANTICYCLONE NEAR 28N120W OVERLYING THE SURFACE 
RIDGE. THE STRONG RIDGE IS STEERING TROPICAL STORM GUILLERMO AND 
TROPICAL DEPRESSION EIGHT-E DUE WEST ALONG ITS SRN PERIPHERY. 

MEXICAN COAST...
THE STRONG UPPER LEVEL ANTICYCLONE WEST OF 110W EXTENDS EWD OVER NW 
MEXICO AND OVERLIES WEAK AND VARIABLE SURFACE FLOW ALONG THE BAJA 
COAST. A WEAK MID/UPPER LEVEL LOW LOCATED OFF THE COAST BETWEEN 
ACAPULCO AND MANZANILLO IS PRODUCING AN AREA OF SCATTERED MODERATE 
CONVECTION FROM 16N-19N BETWEEN 99W-105W. OTHERWISE...A FEW 
SHOWERS/TSTMS ARE AFFECTING THE COAST SOUTH OF ACAPULCO IN ASSOCIATION 
WITH A SERIES OF TROPICAL WAVES MOVING OUT OF THE CARIBBEAN.

$$
BERG