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Eastern Pacific Tropical Weather Discussion (Text)



000
AXPZ20 KNHC 250945
TWDEP 

TROPICAL WEATHER DISCUSSION                                     
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
1005 UTC MON MAY 25 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY  
THROUGH 0945 UTC. 

...TROPICAL LOWS...

A 1010 MB LOW PRESSURE IS ANALYZED NEAR 08N121W AND IS MOVING W  
AT ABOUT 15 KT. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS 
OBSERVED OVER ITS N SEMICIRCLE...FROM 08-13N BETWEEN 115-124W. 
THIS LOW IS FORECAST TO CONTINUE W AND GRADUALLY LOSE IDENTITY 
BY MID WEEK.

A 1009 MB LOW PRES IS OBSERVED NEAR 12.5N132W AND IS MOVING JUST 
N OF DUE W AT ABOUT 7 KT. THE LOW LEVEL CENTER WAS EXPOSED ON 
THE LAST VISIBLE SATELLITE IMAGERY ON SUN EVENING WITH SCATTERED 
MODERATE ISOLATED STRONG CONVECTION WELL E OF THE CENTER FROM 10-
15N BETWEEN 125-131W DUE TO STRONG WESTERLY SHEAR. THE POTENTIAL 
FOR TROPICAL CYCLONE DEVELOPMENT IS BECOMING LESS LIKELY WITH 
TIME...AND EXPECT THIS LOW TO WEAKEN TO AN OPEN TROUGH FROM 
16N135W TO 12N134W TO 09N140W LATE TONIGHT. ASSOCIATED WINDS HAS 
DIMINISHED TO 15-20 KT. COMBINED SEAS OF 7-9 FT CURRENTLY 
OBSERVED WITHIN 390 NM OVER THE NW SEMICIRCLE WILL SUBSIDE TO 
LESS THAN 8 FT ON TUE.   

...TROPICAL WAVES...

A TROPICAL WAVE EXTENDS FROM 02N84W TO 11N86W WITH A 1010 MB LOW 
PRESSURE ALONG THE WAVE AXIS AT 09N86W. SCATTERED MODERATE 
ISOLATED STRONG CONVECTION IS NOTED WITHIN 120 NM OF COAST OF 
CENTRAL AMERICA FROM 78W TO 86W.

A TROPICAL WAVE WAS ANALYZED FROM 02N102W TO 13N101W AND IS 
MOVING W AT ABOUT 12 KT. SCATTERED MODERATE ISOLATED STRONG 
CONVECTION IS OBSERVED FROM 02-08N BETWEEN 92-103W. LOW PRESSURE 
IS FORECAST TO SOON DEVELOP ALONG THIS TROPICAL WAVE. THE 
GRADIENT WILL INCREASE OVER THE SE SEMICIRCLE OF THE LOW AROUND 
MID WEEK WITH THE POSSIBILITY FOR TROPICAL CYCLONE DEVELOPMENT 
INCREASING LATE IN THE WEEK. 

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...

A KELVIN WAVE HAS MOVED INTO THE DEEP TROPICS W OF 115W AND HAS 
DISRUPTED THE LOW LEVEL WINDS. CURRENTLY THERE IS NOT A WELL 
DEFINED MONSOON TROUGH OR ITCZ.   

SCATTERED MODERATE ISOLATED STRONG CONVECTION IS OBSERVED ACROSS 
THE DEEP TROPICS WITHIN 60 NM EITHER SIDE OF LINES FROM 01N85W 
TO 07N90W...AND  FROM 01N103W TO 05N116W. 

A SURFACE LOW IS ANALYZED OVER THE CARIBBEAN COAST OF COLOMBIA 
NEAR 10N75W AND TRAILS A SURFACE TROUGH SW ALONG THE PACIFIC 
COAST OF COLOMBIA TO NEAR 03.5N78W. CONVECTION HAS BEEN FLARING 
INTERMITTENTLY ALONG THIS TROUGH BUT IS CURRENTLY SUPPRESSED AND 
ONLY A FEW SMALL CLUSTERS OF MODERATE CONVECTION IS NOTED ALONG 
THE PACIFIC COAST OF COLOMBIA.

...DISCUSSION...

AN UPPER CYCLONE IS W OF THE AREA NEAR 31N143W WITH AN UPPER  
TROUGH EXTENDING S TO BASE NEAR 20N140W. ALTHOUGH AN ASSOCIATED 
SURFACE FRONTAL TROUGH WILL ADVANCE SLOWLY E AND DISSIPATE ALONG 
140W LATER TODAY...THE GRADIENT IS SUPPORTING SE 20-25 KT WINDS 
AND 7-9 FT SEAS ACROSS THE DISCUSSION WATERS FROM 29-32N W OF 
136W. THE GRADIENT WILL RELAX TODAY WITH WINDS DIMINISHING TO SE 
AT 15-20 KT...AND THE ASSOCIATED SEAS ARE EXPECTED TO SUBSIDE TO 
5-7 FT LATE TONIGHT.

AN UPPER TROUGH EXTENDS S ACROSS MEXICO ALONG 108W TO BASE OVER 
THE EPAC NEAR 18N107W...AND CONTINUES TO ADVECT VERY DRY UPPER 
AIR SE ACROSS THE SUBTROPICS BETWEEN 117-102W.  

AN UPPER ANTICYCLONE IS CENTERED OVER THE TROPICS NEAR 14N117W 
WITH AN UPPER RIDGE EXTENDING W TO BEYOND 10N140W. AN UPPER 
RIDGE ALSO EXTENDS NW TO BEYOND 32N129W AND SEPARATES THE AREAS  
OF UPPER CYCLONIC FLOW PREVIOUSLY DESCRIBED. UPPER MOISTURE IS 
ADVECTED ACROSS THE RIDGE CREST TO ALONG 120W. SOME OF THIS 
MOISTURE MAY REACH THE CENTRAL BAJA PENINSULA LATE TONIGHT AS 
THE BAND OF DRY UPPER AIR SHIFTS EASTWARD.  

AN UPPER ANTICYCLONE OVER COLOMBIA RIDGES WNW TO A CREST NEAR 
10N103W AND IS ENHANCING THE CONVECTION OVER THE SE TROPICAL 
AREA AS PREVIOUSLY DESCRIBED. SOME OF THE DEBRIS MOISTURE IS 
ADVECTED NE ACROSS THE SOUTHERN CARIBBEAN AND SOME OF THE 
MOISTURE IS SPREADING S ACROSS THE EQUATOR BETWEEN 80-120W.

A SURFACE RIDGE EXTENDS FROM 32N131W TO 15N100W. TO THE NE OF 
THE RIDGE ARE NW WINDS AT 10-15 KT WITHIN ABOUT 180 NM W OF THE 
PACIFIC COAST OF THE BAJA PENINSULA WITH COMBINED SEAS OF 3-5 
FT. LITTLE CHANGE EXPECTED THROUGH THU NIGHT...THEN THE  
GRADIENT SHOULD FURTHER RELAX ON FRI SUPPORTING NW WINDS AT 10 
KT WITH SEAS SUBSIDING TO 3-4 FT. 

GULF OF PAPAGAYO...CURRENTLY ENE 20-25 KT WINDS SHOULD DIMINISH 
AFTER SUNRISE THIS MORNING...THEN EXPECT NOCTURNAL 15-20 KT 
PULSES THE REMAINDER OF THE WEEK. 

$$ 
NELSON

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Page last modified: Monday, 25-May-2015 09:46:06 UTC