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AXPZ20 KNHC 302216 CCA
TWDEP

TROPICAL WEATHER DISCUSSION...CORRECTED
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC TUE JUN 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2130 UTC.


...TROPICAL WAVES...

TROPICAL WAVE ALONG 88W/89W FROM 05N TO 12N. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS NOTED FROM FROM 05N TO 08N BETWEEN 86W AND 93W. AN ASCAT PASS FROM 16 UTC INDICATED A WEAK PRESENTATION OF THE WAVE AT THE SURFACE...BUT THIS IS ALSO INFLUENCED BY GAP WIND FLOW EMINATING FROM THE GULF OF PAPAGAYO.

TROPICAL WAVE ALONG 99W/100W FROM 08N TO 15N. THERE IS SOME INDICATION OF THE WAVE IN THE LOWER TO MID LEVELS OF THE ATMOSPHERE BASED ON GOES HIGH DENSITY WINDS AND ANIMATED PRECIPITABLE WATER VALUES...AND TO SOME EXTENT THE 12 UTC SOUNDING FROM ACAPULCO TO THE NORTH OF THE WAVE. THERE MAY BE SOME INTERACTION WITH A NEGATIVELY TILTED UPPER TROUGH REACHING FROM AN UPPER LOW CENTERED NEAR 22N120W TO 19N105W. CONVERGENT EASTERLY WINDS AND FAVORABLE WINDS ALOFT ARE ALLOWING SCATTERED MODERATE TO STRONG CONVECTION EAST OF THE WAVE FROM 08N TO 14N BETWEEN 95W AND 100W.

TROPICAL WAVE ALONG 123W/124W FROM 07N TO 15N. THE WAVE IS ENTERING AN AREA OF STRONG MID TO UPPER LEVEL SUBSIDENCE ON THE SW SIDE OF AN UPPER LOW...WITH ONLY A FEW SHOWERS RELATED TO TRADE CONVERGENCE NOTED NEAR THE WAVE ITSELF...WITHIN THE DEEPER MOISTURE S OF 12N. THE WAVE IS RELATIVELY POORLY DEPICTED IN AVAILABLE SATELLITE IMAGERY AND SURFACE DATA.

TROPICAL WAVE ALONG 134W/135W FROM 07N TO 14N. THE WAVE SHOWS UP WEAKLY ON GOES DERIVED HIGH DENSITY WINDS AND IN VISIBLE IMAGERY. NO SIGNIFICANT CONVECTION IS NOTED WITH THE WAVE. EARLIER SCATTEROMETER DATA INDICATED THERE IS SOME ENHANCEMENT TO TRADE WIND FLOW NW OF THE WAVE BETWEEN THE WAVE AND THE SUBTROPICAL RIDGE TO THE NORTH.


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

NO MONSOONAL CIRCULATION IS EVIDENT ACROSS THE REGION. THE ITCZ EXTENDS FROM 06N103W TO 09N115W TO BEYOND 06N140W. SCATTERED MODERATE CONVECTION NOTED WITHIN 150 NM N AND 120 NM S OF AXIS BETWEEN 115W AND 125W. SCATTERED MODERATE CONVECTION NOTED WITHIN 240 NM S OF AXIS BETWEEN 125W AND 135W.


...DISCUSSION...

N OF 15N E OF 120W...A MID LATITUDE UPPER LEVEL BLOCKING PATTERN CONTINUES TO SPAN THE WESTERN STATES AND THE ADJACENT OCEANIC AREAS TODAY. TO THE SOUTH OF THIS RIDGE...A LARGE MIDDLE/UPPER LEVEL CYCLONIC CIRCULATION CENTERED NEAR 22N120W WITH A SHARP NEGATIVELY TILTED TROUGH REACHING TOWARD 19N105W. A FEW SHOWERS AND THUNDERSTORMS WAS NOTED MOVING ACROSS NW MEXICO AND THE CENTRAL GULF OF CALIFORNIA IN THE DIVERGENT FLOW ALOFT BETWEEN THESE FEATURES...BUT THIS IS DIMINISHING. A WEAK SUBTROPICAL RIDGE IS MAINTAINING FAIRLY LIGHT SURFACE WINDS ACROSS THE REGION. SUCCESSIVE ALTIMETER PASSES FROM THE MORNING INDICATED ONLY 3 TO 5 FT SEAS IN MOST AREAS. NO CHANGES ARE EXPECTED THROUGH THU IN THE PATTERN. LOOKING AHEAD TO LATE IN THE WEEK...WINDS WILL INCREASE SLIGHTLY OFF THE COAST OF BAJA CALIFORNIA NORTE AND NORTHERN PORTIONS OF BAJA CALIFORNIA SUR BETWEEN THE RIDGE TO THE WEST AND LOWER PRES OVER NW MEXICO.

S OF 15N E OF 110W...STRONG TRADE WIND FLOW THROUGH THE SW CARIBBEAN IS PUSHING INTO THE EASTERN PACIFIC THROUGH THE GULF OF PAPAGAYO AND OTHER LOCATIONS ALONG THE COAST OF NICARAGUA TO THE GULF OF FONSECA. OVERNIGHT ASCAT DATA INDICATED 20 TO 25 KT THIS MORNING...AND THIS WILL PERSIST THROUGH THE NEXT 24 TO 36 HOURS WITH SEAS BUILDING AS HIGH AS 11 FT. FRESH NORTHERLY GAP WINDS WERE ALSO NOTED INTO THE GULF OF PANAMA. CONVECTION ADJACENT TO A PAIR OF WEAK TROPICAL WAVES NEAR 89W AND 100W IS RELATED IN PART TO AN UPPER TROUGH NORTH OF THE AREA. OTHERWISE FAIRLY LIGHT AND DISORGANIZED FLOW IN THE DEEP TROPICS IS NOTED IN TOGA BUOY OBSERVATIONS AND EARLIER ASCAT DATA. THE WINDS AND SEAS ARE EXPECTED TO DIMINISH TO 20 KT OR LESS AND LESS THAN 8 FT THROUGH 36 HOURS. ALTIMETER DATA IS INDICATING GENERALLY 4 TO 5 FT SEAS OUTSIDE OF AREA OF GAP WIND INFLUENCE.

ELSEWHERE...THE SUBTROPICAL RIDGE N OF 20N IS MAINTAINING GENERALLY MODERATE TRADE WIND FLOW INTO THE DEEP TROPICS...EXCEPT FOR NEAR THE TROPICAL WAVE AT 135W...WHERE SATELLITE DERIVED DATA INDICATES FRESH TRADES AND SEAS TO 8 FT FROM 11N TO 15N W OF 133W. DESPITE RICH DEEP LAYER MOISTURE IN THE TROPICS SOUTH OF 15N...CONVECTION IS MODEST DUE SUBSIDENT FLOW ALOFT RELATED TO THE UPPER LOW CENTERED NEAR 22N120W. NO MAJOR CHANGES EXPECTED THROUGH THE NEXT 48 HOURS AT THE SURFACE. LOOKING AHEAD...GLOBAL MODELS INDICATE WEAK LOW PRES FORMING IN THE DEEP TROPICS BETWEEN 135W AND 140W BY THIS WEEKEND...POSSIBLY RELATED TO A SHIFT IN THE UPPER LOW N OF THE AREA TO A POSITION FARTHER WEST THROUGH FRI.

$$ CHRISTENSEN

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