Hurricane Advisories Hurricane advisories

000
AXPZ20 KNHC 270943
TWDEP

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC FRI JAN 27 2012

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
0900 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
MONSOON TROUGH EXTENDS FROM 07N78W TO 04N90W. ITCZ EXTENDS FROM
04N90W TO 04N105W TO 06N110W TO 04N125W TO 05N140W. SCATTERED
MODERATE CONVECTION IS NOTED WITHIN 45 NM EITHER SIDE OF A LINE
FROM 12N105W TO 09N115W.

...DISCUSSION...

BROAD MID TO UPPER LEVEL TROUGH EXTENDS ALONG 105W FROM NW
MEXICO TO 05N. TRADE WIND CONVERGENCE NEAR THE ITCZ ALONG WITH
DIVERGENCE ALOFT ASSOCIATED WITH THE UPPER TROUGH ARE TOGETHER
ENHANCING A LINE OF SCATTERED MODERATE CONVECTION WITHIN 45 NM
EITHER SIDE OF A LINE FROM 12N105W TO 09N115W. A 0524 UTC ASCAT
PASS INDICATED AN ASSOCIATED SURFACE TROUGH ALONG 113W. SINCE
THIS FEATURE HAS MIGRATING W OF THE UPPER TROUGH INTO THE
SUBSIDENT AREA OF A SHORT WAVE RIDGE...THE TROUGH AND ASSOCIATED
CONVECTION WILL LIKELY DIMINISH THROUGH OVER THE NEXT 24 HOURS.

W OF THE UPPER RIDGE...A QUASISTAIONARY UPPER LOW IS CENTERED
NEAR 15N140W. SENSORS PICKED SOME LIGHTNING STRIKES IN THE AREA
JUST TO THE SE OF THE UPPER LOW N OF THE ITCZ TO 12N BETWEEN
125W AND 130W...BUT THIS HAS SINCE DIMINISHED.

FURTHER NORTH...STRONG SURFACE PRES CENTERED OFF THE OREGON
COAST IS MAINTAINING 20 KT NE TO E WINDS OVER THE WATERS N OF
24N W OF 125W...AS NOTED IN EARLIER SHIP AND SCATTEROMETER DATA.
THE WINDS WILL DIMINISH THROUGH LATE SAT AS THE SURFACE HIGH
PRES WEAKENS AND SHIFT FURTHER S. MEANWHILE...NW SWELL CONTINUES
TO PUSH INTO THE AREA AND WILL ENCOMPASS MUCH OF THE AREA N OF
05N W OF 110W BY LATE SAT...MIXING WITH NE SWELL ASSOCIATED WITH
TRADE WINDS GENERALLY FROM 05N TO 10N W OF 120W.

GULF OF CALIFORNIA...A SHORT WAVE TROUGH WILL EMERGE OUT OF THE
NW FLOW ALOFT AND PUSH SE ACROSS THE GULF OF CALIFORNIA STARTING
EARLY SAT...BEFORE DEAMPLIFYING AND LIFT NE SUN. NW SURFACE
WINDS INCREASE ACCORDINGLY DOWN THE LENGTH OF THE GULF
SAT...REACHING 20 TO 25 KT BY LATE SAT BEFORE DIMINISHING BELOW
20 KT BY LATE SUN AS THE SUPPORTING UPPER TROUGH LIFTS OUT.

GULF OF TEHUANTEPEC...1020 MB SURFACE HIGH PRES IS BUILDING OVER
NE MEXICO BEHIND A WEAK COLD FRONT MOVING THROUGH THE CENTRAL
GULF OF MEXICO. THE COLD AIRMASS BEHIND THE FRONT IS FAIRLY
MILD...AND THE SURFACE HIGH PRES REMAINS. A 0552 UTC OSCAT PASS
SHOWED WINDS TO 25 KT IN THE GULF OF TEHUANTEPEC. HIGHER WINDS
MAY STILL OCCUR LATER IN THE MORNING DUE TO DRAINAGE
EFFECTS...BUT THE DURATION OF THE GALE WARNING IN EFFECT FOR
TEHUANTEPEC HAS BEEN SHORTENED SLIGHTLY TO 18 UTC TO ACCOUNT FOR
WEAKENING TREND IN THE PATTERN. LOOKING AHEAD...A REINFORCING
FRONT FOLLOWED BY A STRONGER HIGH PRES WILL ENTER THE GULF OF
MEXICO LATE SAT INTO SUN. EXPECT WINDS TO SURGE TO GALE FORCE
THROUGH THE GULF OF TEHUANTEPEC BY EARLY SUN.

GULF OF PAPAGAYO...20 TO 25 KT GRADIENT FLOW OVER THE SW
CARIBBEAN ALONG WITH OVERNIGHT DRAINAGE EFFECTS WILL SUPPORT 20
KT GAP WINDS THROUGH THE GULF OF PAPAGAYO REACHING AS FAR AS
88W...MAINLY DURING THE OVERNIGHT HOUR AND EARLY MORNING HOURS.

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CHRISTENSEN