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Eastern North Pacific Tropical Weather Discussion



000
AXPZ20 KNHC 282202
TWDEP 

TROPICAL WEATHER DISCUSSION                                  
NWS NATIONAL HURRICANE CENTER MIAMI FL                      
2205 UTC THU APR 28 2016

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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2145 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...        

A SURFACE TROUGH EXTENDS FROM 11N87W TO 11N97W TO 08N103W TO
07N110W WHERE SCATTEROMETER DATA SUGGESTS IT THEN TRANSITIONS TO
THE ITCZ AXIS FROM THERE TO 09N116W TO 07N126W TO 05N132W TO
BEYOND 04N140W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS
WITHIN 240 NM S OF THE TROUGH BETWEEN 98W-99W...WITHIN 120 NM OF
THE AXIS BETWEEN 120W-123W...AND WITHIN 60 NM N OF THE AXIS
BETWEEN 112W-115W. SCATTERED MODERATE CONVECTION IS WITHIN 120
NM N OF THE AXIS BETWEEN 123W-127W...AND BETWEEN 128W-130W.
SIMILAR ACTIVITY IS S OF THE TROUGH WITHIN 60 NM OF A LINE FROM
06N89W TO 06N93W...AND N OF THE TROUGH WITHIN 30 NM OF A LINE
FROM 11N96W TO 13N93W.

...DISCUSSION...

A LARGE UPPER ANTICYCLONE IS CENTERED OVER THE FAR EASTERN PART
OF THE AREA NEAR 12N99W WITH IS BROAD ANTICYCLONIC FLOW NOTED TO
THE S OF 21N AND E OF ABOUT 128W. N OF 21N...BROAD UPPER
TROUGHING IS PRESENT E OF 128W...AND W OF 128W WITH A MEAN
TROUGH AXIS STRETCHING FROM A NEARLY STATIONARY LARGE UPPER LOW
OVER THE WESTERN U.S. SW TO 26N121W TO 20N134W TO SW OF THE AREA
AT 16N140W. THE TROUGH SUPPORTS A COLD FRONT THAT EXTENDS FROM
SE ARIZONA TO ACROSS NORTHERN BAJA CALIFORNIA...TO 28N120W AND
NW TO 29N128W. THE FRONT IS MOVING QUICKLY S AS SEEN ON
SATELLITE IMAGERY. A SURGE OF STRONG TO NEAR GALE FORCE NW WINDS
WAS CAPTURED BY AN ASCAT PASS FROM THIS AFTERNOON JUST N OF 32N
BETWEEN 117W-123W. THE FRONT IS FORECAST TO DISSIPATE OVER
INLAND NORTHERN MEXICO ON FRI. A VERY WELL PRONOUNCED
SUBTROPICAL JET STREAM BRANCH SEPARATES THE ANTICYCLONIC FLOW
WITH THE CYCLONIC FLOW ASSOCIATED WITH THE UPPER TROUGH. THE JET
STREAM BRANCH IS ALONG 13N132W 21N120W 22N110W...AND E TO OVER
CENTRAL MEXICO. MODERATE TO STRONG WINDS WITH THE JET ARE
TRANSPORTING OVERCAST TO BROKEN MID AND HIGH CLOUDS EASTWARD
TOWARDS CENTRAL MEXICO FROM NEAR MANZANILLO TO MAZATLAN. THESE
CLOUDS ARE WITHIN 350 NM S OF THE JET STREAM W OF 116W...AND
WITHIN 180-240 NM S OF THE JET E OF 116W. THE ANTICYCLONIC FLOW
OVER EASTERN PORTION IS HELPING TO MAINTAIN CONVECTION OCCURRING
THERE AS DESCRIBED ABOVE UNDER ITCZ/MONSOON TROUGH.

HIGH PRESSURE OF 1030 MB IS CENTERED NW OF THE AREA NEAR 33N145W
WITH A RIDGE EXTENDING SOUTHEASTWARD INTO THE AREA THROUGH
32N140W TO 25N130W 21N119W. THE PRES GRADIENT BETWEEN THE
RIDGE AND LOWER PRES IN THE VICINITY OF THE ITCZ IS ALLOWING FOR
MODERATE TO FRESH NE TO E TRADES TO EXIST FROM 09N-21N W OF 132W.
ANOTHER COLD FRONT IS FORECAST TO SWEEP ACROSS THE FAR NE PART
AND NORTHERN BAJA CALIFORNIA SAT NIGHT INTO EARLY SUN. WINDS
AHEAD OF THE FRONT OVER THE NORTHERN GULF ARE FORECAST TO BE
NEAR GALE FORCE DURING THAT TIME FRAME. THE RIDGE IS FORECAST 
TO WEAKEN FRI NIGHT INTO SAT ALLOWING FOR THE TRADES TO 
DIMINISH TO MOSTLY MODERATE INTENSITY.  

OTHERWISE...NW SWELL WITH SEAS OF 8-10 FT WILL CONTINUE TO
PROPAGATE SE ACROSS MUCH OF THE AREA THROUGH SAT. THE SWELL IS
FORECAST TO SUBSIDE SAT NIGHT INTO SUN.

$$
AGUIRRE