Tropical Weather Discussion
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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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