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Eastern Pacific Tropical Weather Discussion (Text)

000
AXPZ20 KNHC 301553
TWDEP 

TROPICAL WEATHER DISCUSSION                                     
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
1605 UTC FRI JAN 30 2015

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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC. 

...SPECIAL FEATURES...                                           
GULF OF TEHUANTEPEC GALE WARNING...A TIGHT PRESSURE GRADIENT 
ACROSS SOUTHERN MEXICO CONTINUES TO SUPPORT A LONG DURATION 
MINIMAL GALE EVENT IN THE GULF OF TEHUANTEPEC. A SCATTEROMETER 
PASS AT 30/0400 UTC SHOWED MAX WINDS AROUND 32 KT...INDICATING 
THAT THE INTENSITY MAY HAVE BEEN WANING OUTSIDE THE PEAK DIURNAL 
DRAINAGE FLOW PERIOD DURING THE EARLY MORNING HOURS OF TODAY. 
THE FORECAST IS THAT THE GALE-FORCE WIND SPEEDS WILL CONTINUE 
FOR THE NEXT 30 HOURS OR SO. A LARGE AREA OF 8-10 FT SEAS EXISTS 
FROM 04N TO 13N BETWEEN 93W AND 109W. THE GRADIENT WILL WEAKEN 
SLOWLY THROUGH SATURDAY. THE WINDS IN THE SOUTHWESTERN GULF OF 
MEXICO ARE FORECAST TO VEER TO THE SOUTHEAST IN RETURN FLOW. 

GULF OF PAPAGAYO GALE WARNING...A TIGHT PRES GRADIENT IN THE FAR 
WESTERN CARIBBEAN SEA CROSSES CENTRAL AMERICA. THE PRESSURE 
GRADIENT WILL CONTINUE FOR THE NEXT 12 HOURS OR SO. THE WIND 
SPEEDS WILL DIMINISH TO FRESH TO STRONG AND DECREASE 
CONSIDERABLY IN AREAL COVERAGE AFTER THE NEXT 12 HOURS OR SO. 
SWELL FROM PAPAGAYO IS COMBINING WITH SEAS GENERATED IN THE 
TEHUANTEPEC CASE...BUT WILL SUBSIDE AND SHRINK EASTWARD AS 
THE WIND SPEEDS DIMINISH THIS WEEKEND.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...AND
CONVECTIVE PRECIPITATION...

.SURFACE TROUGH FROM 06N77W TO 03N80W. SCATTERED MODERATE 
ISOLATED STRONG FROM 03N TO 06N BETWEEN 77W AND 79W.

ITCZ AXIS FROM 07N85W TO 03N97W TO 06N128W TO 06N140W. NUMEROUS 
STRONG FROM 05N TO 06N BETWEEN 110W AND 112W. SCATTERED MODERATE 
ISOLATED STRONG WITHIN 120 NM SOUTH OF ITCZ AND WITHIN 60 NM 
NORTH OF ITCZ BETWEEN 113W AND 123W.

...DISCUSSION...                                                
A MIDDLE LEVEL TO UPPER LEVEL TROUGH PASSES THROUGH 32N117W TO 
24N118W TO 18N118W TO 16N123W. BROKEN TO OVERCAST MULTILAYERED 
CLOUDS ARE FROM 15N NORTHWARD FROM 120W EASTWARD...HEADING INTO 
MEXICO AND THE SOUTHWESTERN PART OF THE U.S.A. THE TROUGH WILL 
SHIFT EASTWARD TODAY...AND THEN FORM A CUT-OFF CYCLONIC 
CIRCULATION CENTER IN NORTHERN ARIZONA ON SATURDAY. 

A SURFACE RIDGE EXTENDS FROM A 1026 MB HIGH PRESSURE CENTER THAT 
IS NEAR 35N132W...TO 27N135W AND 20N141W. ASCAT SCATTEROMETER 
PASSES HAVE BEEN SHOWING FRESH TO STRONG NE TRADES TO THE WEST 
OF 135W FROM THE ITCZ NORTHWARD. FRESH TRADE WINDS ARE EXPECTED 
TO CONTINUE FROM 123W WESTWARD THROUGH EARLY SUNDAY.

THE PRESSURE GRADIENT THAT EXISTS BETWEEN A HIGH PRESSURE CENTER 
THAT IS IN THE GREAT BASIN AND TROUGHING THAT IS TO THE WEST OF 
THE SIERRA MADRE OCCIDENTAL IS INDUCING FRESH TO STRONG 
NORTHWEST WINDS IN THE SOUTH-CENTRAL GULF OF CALIFORNIA...WITH 
HIGHEST WINDS GREATER THAN 25 KNOTS NEAR 27N BASED ON THE 
30/0400 UTC ASCAT PASS. THE WIND SPEEDS ARE EXPECTED TO DIMINISH 
BELOW 20 KT BY THIS AFTERNOON. 

FRESH TO STRONG WINDS WILL CONTINUE TO PULSE IN THE GULF OF 
PANAMA FOR THE NEXT 48 HOURS...IN INCREMENTS OF 12-HOUR PERIODS. 
THE FORECAST PERIOD STARTS WITH THE COVERAGE FROM 03N NORTHWARD. 
THE COVERAGE WILL CUT BACK AND REACH ONLY 6N OR 7N DURING THE 
WEAKER MOMENTS...AND THE COVERAGE WILL REACH 03N DURING THE 
TIMES OF GREATER COVERAGE IN THE EASTERN PACIFIC OCEAN.

$$ 
MT