000
AXPZ20 KNHC 271605
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC WED OCT 27 2010

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W.

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1545 UTC.

...ITCZ...

AXIS CENTERED ALONG 9N85W TO 1009 MB LOW NEAR 10N93W TO 9N100W
TO 11N110W TO 1009 MB LOW NEAR 11N119W TO 8N130W TO 8N140W.
SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 30 NM 
OF THE AXIS E OF 88W...BETWEEN 121W-123W AND WITHIN 120 NM N OF
THE AXIS BETWEEN 105W-108W.

...DISCUSSION...

THE UPPER PATTERNS REMAINS SOMEWHAT COMPLEX AS TWO UPPER LEVEL
CYCLONIC CIRCULATIONS NOTED NEAR 6N126W...AND OVER THE NW 
PORTION OF THE AREA MOVING NE NEAR 22N137W ARE CONNECTED BY A
SHARPENING TROUGH AXIS FROM THE NORTHERN MOST CIRCULATION TO
THE ONE NEAR 6N126W. A RATHER VIGOROUS DEEPENING UPPER TROUGH
IS PRESSING TOWARDS THE FAR NW CORNER OF THE AREA. THE TROUGH
WILL SWING SE AND E ACROSS THE FAR NORTHERN PORTION THU INTO
FRI NIGHT AS A STRONG UPPER LOW WELL N OF THE REGION NEAR
44N137W DIVES SEWD TO NEAR 25N126W BY FRI NIGHT...THEN TRACKS
EWD ACROSS THE WESTERN U.S. SAT. UPPER LEVEL MOISTURE IN THE FORM
OF SCATTERED TO BROKEN HIGH CLOUDS IS STREAMING NEWD INTO THE
NW AN N PORTION S OF THE AREA AHEAD OF THE UPPER TROUGH. SIMILAR
MOISTURE IS NOTED BETWEEN THE TWO UPPER LEVEL CYCLONIC 
CIRCULATIONS
FROM 11N TO 15N W OF 133W...AND FROM 13N TO 25N BETWEEN 
130W-134W.

OVER THE EASTERN PORTION OF THE AREA...BROAD ANTICYCLONIC ALOFT 
COVERS THE AREA N OF 10N BETWEEN 112W AND 131W WITH A SMALL 
ANTICYCLONE
LOCATED NEAR 15N113W. SLIGHT CONFLUENT FLOW TO THE SE OF THE 
UPPER
TROUGH IS HELPING TO SUSTAIN SCATTERED MODERATE/ISOLATED STRONG 
CONVECTION
TO NE OF A 1009 MB LOW NEAR 11N119W FROM 12N TO 14N BETWEEN 117W 
AND 120W...AND ALSO SCATTERED MODERATE CONVECTION WITHIN 120 NM 
SW
OF THE LOW. AN UPPER LEVEL ANTICYCLONE CENTERED E OF THE AREA 
JUST TO THE E OF BELIZE EXTENDS A RIDGE WESTWARD TO ACROSS 
SOUTHEASTERN
MEXICO AND TO NEAR 16N109W. TO THE S OF THE RIDGE...ITCZ 
CONVECTION
IS ACTIVE E OF ABOUT 92W. MODERATE UPPER LEVEL EASTERLY WINDS 
ARE NOTED ION SATELLITE-DERIVED DATA S OF THE RIDGE TO 2N AND 
E OF 95W. WATER VAPOR IMAGERY SHOWS ABUNDANT MODERATE SUBSIDING 
AND RESULTING DRY STABLE AIR TO S OF 30N AND E OF THE UPPER 
TROUGH
...EXCEPT NEAR AND ALONG THE ITCZ WITH CONVECTION DESCRIBED 
ABOVE.

AT THE SURFACE...A STRONG PACIFIC COLD FRONT ASCOIATED WITH THE 
DEEPENING UPPER TROUGH EXETENDS FROM 32N136W TO JUST W OF THE 
AREA NEAR 30N145W. THE FRONT WILL MOVE TO ALONG 32N131W TO 
27N136W TO 26N140W IN ABOUT 24 HOURS WITH NW TO N WINDS OF 20 KT
BEHIND IT N OF 27N...AND FOLLOWED WITH A NEW TRAIN OF LARGE 
LONG PERIOD NW SWELLS...POSSIBLY REACHING UP 15 FT IN 48 HOURS
BEHIND IT N OF 26N. N OF 29N WITHIN 120 NM E OF FRONT SW WINDS
OF 20 KT WITH SEAS 8 TO 12 FT IN NW SWELL BY 48 HOURS.

$$
AGUIRRE