000
AXPZ20 KNHC 241604
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC TUE FEB 24 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 
1545 UTC. 

...SPECIAL FEATURE... 

GULF OF TEHUANTEPEC GALE WARNING...STRONG HIGH PRES RIDGING OVER 
SOUTHEASTERN MEXICO HAS RELAXED SOME SINCE 24 HRS AGO WITH 
MINIMAL GALE FORCE N-NE WINDS OF 30-35 KT WITHIN 30 NM EITHER 
SIDE OF A LINE FROM 16N95W TO 14.5N95W WITH SEAS OF 9-13 FT. THE 
PRESENT PRES GRADIENT IS SUPPORTING N-NE WINDS OF 20-30 KT 
ELSEWHERE WITHIN 60 NM EITHER SIDE OF A LINE FROM 16N95W TO 
13.5N96.5W WITH SEAS OF 8-10 FT. LATEST SEA SURFACE TEMPERATURE 
ANALYSIS REVEALED TEMPERATURES OF 25.0-25.5 DEGREE CELSIUS IN AN 
AREA OF COLD UPWELLED WATER DOWNSTREAM FROM THE GULF FROM 13N-
15N BETWEEN 94W-96W. MODEL GUIDANCE DEPICTS THE PRES GRADIENT 
CAUSING THE TIGHT GRADIENT TO CONTINUE TO SLACKEN THROUGH THE 
NEXT 12-30 HRS ALLOWING FOR THE PRESENT GALE FORCE WINDS TO 
DIMINISH TO JUST BELOW GALE FORCE BY EARLY THIS EVENING...AND TO 
20 KT OR LESS BY LATE TONIGHT WITH RESIDUAL NE SWELLS RESULTING 
IN SEAS TO 8 FT. THESE SEAS SHOULD SUBSIDE TO LESS THAN 8 FT BY 
12 UTC THU.
  
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... 

THE ITCZ EXTENDS FROM 06N90W TO 04N100W TO 05N110W TO 04N118W TO 
04N124W. SCATTERED MODERATE CONVECTION IS WITHIN 150 NM N OF THE 
ITCZ BETWEEN 108W-112W.

...DISCUSSION... 

ALOFT...A NARROW UPPER TROUGH EXTENDS FROM 32N136W SW TO 
24N140W...AND SE TO A RATHER VIGOROUS AND LARGE UPPER LOW NEAR 
14N139W. THE TROUGH CONTINUES SE TO 10N134W...AND TO NEAR 
09N121W. A SURFACE TROUGH REFLECTION OF THE UPPER LOW IS 
ANALYZED FROM 08N138W TO WEAK LOW PRES NEAR 13N137W AND TO 
19N137W TO 23N135W. SCATTERED SHOWERS AND ISOLATED TSTMS DUE TO 
COLD AIR INSTABILITY ALOFT ARE SEEN FROM 10N TO 19N W OF 135W. 
TO THE E OF THE TROUGH...BROAD UPPER LEVEL RIDGING DOMINATES THE 
AREA BETWEEN 119W-134W. A SMALL ANTICYCLONE IS AT 06N94W WITH A 
RIDGE AXIS EXTENDING N TO THE ISTHMUS OF TEHUANTEPEC...AND N 
FROM THERE TO NEAR 20N108W. THE UPPER FLOW IS MOSTLY ZONAL TO 
THE NW AND N OF THIS RIDGE. UPPER DEBRIS MOISTURE...IN THE FORM 
OF SCATTERED TO BROKEN CIRRUS CLOUDS...IN THE ZONAL FLOW IS 
STREAMING EWD ACROSS BAJA CALIFORNIA AND OVER SOME SECTIONS OF 
NORTHERN MEXICO.

SATELLITE IMAGERY SHOWS VERY ACTIVE WEATHER IN THE FORM OF 
INCREASING SCATTERED STRONG CONVECTION FROM 13N TO 18N. THIS 
ACTIVITY IS UNDERNEATH THE UPPER DIFFLUENT PATTERN FOUND TO THE 
E OF THE UPPER LOW NEAR 14N139W...AND IS FURTHER BEING ENHANCED 
BY A SURFACE TROUGH ANALYZED FROM 03N126W TO 08N125W TO 13N126W 
TO 18N126W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS 
WITHIN 30 NM OF THE TOUGH FROM 13N TO 16N. UPPER DEBRIS MOISTURE 
FROM THIS ACTIVITY IS NOTED STREAMING TO THE N FROM 07N TO 30N 
BETWEEN 121W AND 137W. THIS MOISTURE THEN TURNS EASTWARD BOUND 
TO THE E OF 121W. MODERATE SUBSIDENCE OBSERVED TO THE W OF THE 
UPPER TROUGH IS SHRINKING WITH TIME AS THE UPPER DEBRIS MOISTURE 
GRADUALLY TRANSLATES WESTWARD. BOTH ASCAT AND RAPIDSCAT DATA 
FROM LAST NIGHT REVEALED NE TO E 20-25 KT WINDS FROM 19N TO 24N 
BETWEEN 125W AND 140W. SEAS ATTRIBUTED TO THESE WINDS HAVE BUILD 
TO THE RANGE OF 8-10 FT. THE UPPER LOW IS FORECAST TO CONTINUE 
WESTWARD EXITING THE AREA THIS EVENING WITH ITS SURFACE TROUGH 
FEATURE MOVING TO JUST W OF THE 140W BY EARLY WED. HOWEVER...THE 
PRES GRADIENT BETWEEN THE TROUGH AND RIDGING THAT BUILDS SEWD 
OVER THE EASTERN AND CENTRAL WATERS WILL MAINTAIN AN AREA OF NE 
TO E 20-25 KT WINDS WITHIN 90 NM OF A LINE FROM 23N140W TO 
22N132W TO 19N130W BY EARLY WED. THESE WINDS WILL DECREASE IN 
COVERAGE THROUGH EARLY WED EVENING...AT WHICH TIME THEY ARE 
FORECAST TO BE CONFINED FROM 23N TO 25N W OF 138W WITH SEAS 
REMAINING AT    8-10 FT. BY EARLY THU...THESE WINDS ARE FORECAST 
TO EXIST FROM 12N TO 14N BETWEEN 133W AND 138W WITH SEAS AT 8-10 
FT.

ELSEWHERE AT THE SURFACE...RIDGING REFERENCED ABOVE EXTENDS FROM 
32N127W SEWD TO 25N120W AND TO NEAR 20N115W. THE TAIL-END OF A 
COLD FRONT IS SWEEPING ACROSS NORTHERN BAJA CALIFORNIA. BEHIND 
IT...NW WINDS OF 20-25 KT ARE OCCURRING WITH SEAS LESS THAN 8 
FT. THIS FRONT WILL CLEAR THE GULF TONIGHT INTO WED. THE PRES 
GRADIENT INDUCE BY THE RIDGE IS ALLOWING FOR NW 15-20 KT WINDS 
TO EXIST ALONG THE BAJA CALIFORNIA PENINSULA. THESE WINDS WILL 
BRIEFLY DIMINISH WED AFTERNOON BEFORE INCREASING AGAIN WED 
EVENING...AND DIMINISHING ON THU. ASSOCIATED SEAS ARE IN THE 
RANGE OF ABOUT 5-7 FT...AND WILL SUBSIDE SLIGHTLY WED. 
 
GAP WINDS...                 
GULF OF CALIFORNIA...AS MENTIONED ABOVE PART OF A COLD FRONT IS 
ACROSS THE FAR NORTHERN PORTION OF THE GULF. THE NW WINDS OF 20-
25 KT N OF 30N WILL SHIFT FROM 26N TO 29N EARLY THIS EVENING
...FROM 25N TO 27N BY LATE TONIGHT WITH LITTLE CHANGE EARLY WED. 
THESE WINDS ARE FORECAST TO DIMINISH TO 20 KT OR LESS BY EARLY 
WED AFTERNOON. SEAS ARE EXPECTED TO BRIEFLY BUILD TO THE RANGE 
OF 6-8 FT FROM 25N TO 27N LATE TONIGHT...THEN SUBSIDE TO 5-6 FT 
WED AFTERNOON...AND ARE FORECAST TO BE IN THE RANGE OF 3-4 FT S 
OF 27N BY EARLY ON THU.
  
GULF OF PAPAGAYO...NE-E WINDS OF 20-25 KT ARE OCCURRING THROUGH 
THE GULF AND WESTWARD TO NEAR 90W. WITH THE PRES GRADIENT 
WEAKENING OVER THE SW CARIBBEAN...THESE WINDS WILL RESPOND BY 
WEAKENING TO 15-20 KT TONIGHT.

$$ 
AGUIRRE