Hurricane Advisories Hurricane advisories

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC THU JAN 26 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2245 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
MONSOON TROUGH 07N77W TO 05N92W. ITCZ AXIS 05N92W TO 07N108W TO
07N127W TO 04N140W. SCATTERED MODERATE ISOLATED STRONG WITHIN
90-120 NM EITHER SIDE OF AXIS BETWEEN 114W AND 125W.

...DISCUSSION...
A BROADENING UPPER LEVEL TROUGH CONTINUES TO DOMINATE THE FAR NE
PORTIONS OF THE AREA...WITH TROUGH AXIS EXTENDING FROM THE
CENTRAL U.S. ALONG 95W...S-SW THROUGH EASTERN TEXAS TO NEAR THE
W COAST OF MEXICO NEAR 20N106W. AN ELONGATED MIDDLE TO UPPER
LEVEL CYCLONE CONTINUED ACROSS FAR W PORTIONS OF THE
AREA...CENTERED NEAR 23N140W...EXTENDING S TO NEAR 07N139W...AND
REMAINS CUT OFF FROM THE MEAN UPPER LEVEL FLOW. IN BETWEEN THESE
TWO TROUGHS WAS A WEAKENING UPPER LEVEL RIDGE CENTERED ON A
MIDDLE LEVEL ANTICYCLONE NEAR 30N127W. A VERY SHARP AND HIGH
AMPLITUDE UPPER TROUGH ACROSS THE CENTRAL PACIFIC IS FORECAST TO
SHIFT E TOWARDS W PORTIONS OF THE AREA FRIDAY AND SAT AND WILL
AID IN KICKING OUT THE CUT OFF LOW AND REORGANIZING THE UPPER
LEVEL FLOW ACROSS THE AREA THROUGH EARLY NEXT WEEK.

THE SURFACE HIGH PRES RIDGE DOMINATING W PORTIONS OF THE AREA
THE PAST SEVERAL DAYS IS GRADUALLY WEAKENING...CURRENTLY
CENTERED NEAR 35N132W ON A 1032 MB HIGH...WITH RIDGE COVERING
THE AREA N OF 15N W OF 108W. NE TO E TRADEWINDS AT 20 KT ARE
OBSERVED ALONG THE SOUTHERN PERIPHERY OF THE THE RIDGE FROM 05N
TO 28N W OF 130W AND FROM 08N TO 14N BETWEEN 120W AND 130W...
WITH COMBINED SEAS RUNNING 8 TO 12 FT IN MIXED NE WIND SWELL AND
LONG PERIOD NW SWELL. THESE FRESH TRADES N OF THE ITCZ CONTINUE
TO GENERATE A SIGNIFICANT CLUSTER OF SCATTERED MODERATE TO DEEP
CONVECTION MENTIONED ABOVE BETWEEN 114W AND 125W...WHICH IS
BEING AIDED BY A SHORT WAVE MOVING NE THROUGH THE BASE OF THE
UPPER TROUGH ALONG 140W. THIS PERSISTENT REGION OF DEEP
CONVECTION OF THE PAST SEVERAL DAYS HAS BEGUN TO CREATE IT'S OWN
UPPER ANTICYCLONE NEAR 06N121W. OTHERWISE...LARGE NWLY SWELLS
PREVAIL ACROSS MUCH OF THE AREA N OF 10N W OF 115W.

A STRONG COLD FRONT IS MOVING ACROSS THE CENTRAL GULF OF MEXICO
EARLY THIS EVENING...EXTENDING FROM THE FLORIDA PANHANDLE TO THE
BAY OF CAMPECHE. STRONG HIGH PRES BUILDING BEHIND THE FRONT WILL
TIGHTEN THE PRES GRADIENT OVER SOUTHERN MEXICO THIS EVENING AND
TONIGHT...AND RESULT IN GALE FORCE WINDS THROUGH THE GULF OF
TEHUANTEPEC BY LATE TONIGHT. THIS GALE EVENT IS FORECAST TO BE
SHORT LIVED...WITH WINDS BELOW GALE FORCE BY FRI NIGHT.

$$
STRIPLING