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AXPZ20 KNHC 252159
TWDEP

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC SAT OCT 25 2014

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 2100 UTC.


...SPECIAL FEATURES... GULF OF TEHUANTEPEC GALE WARNING...STRONG HIGH PRESSURE ACROSS THE WESTERN GULF OF MEXICO IS WORKING IN CONJUNCTION WITH AN AREA OF LOW PRES IN THE EASTERN PACIFIC NEAR 10N94W TO DRIVE NORTHERLY WINDS THROUGH THE CHIVELA PASS INTO THE GULF OF TEHUANTEPEC. AN 1545 UTC ASCAT SATELLITE PASS OVER THE REGION SHOWED WINDS TO GALE FORCE...AT A TIME WHEN WINDS ARE LIKELY DIMINISHING SLIGHTLY AFTER THE EARLY MORNING HOURS WHEN WINDS ARE STRONGEST. THE HIGHER RESOLUTION MODEL OUTPUT SUGGESTS THE GALE FORCE WINDS BELIEVED TO BE IN PLACE NOW WILL NOT DIMINISH BELOW GALE FORCE UNTIL AFTER THE PERIOD OF PEAK DRAINAGE FLOW ENDS ON SUNDAY. AFTERWARD...THE DRY AIR IN PLACE ASSOCIATED WITH THE GAP WIND FLOW SHOULD BEGIN TO MODIFY 24-48 HOURS FROM NOW...ALLOWING FOR INCREASED CONVECTION NEAR THE LOW PRES SYSTEM. GLOBAL GUIDANCE SUGGESTS THAT CYCLOGENESIS MAY OCCUR IN THIS AREA AFTER THAT TIME.


...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... MONSOON TROUGH AXIS FROM 11N86W TO LOW PRES NEAR 10N94W 1010 MB TO 08N105W TO LOW PRES NEAR 10N110W 1011 MB TO LOW PRES NEAR 12N117W 1012 MB TO LOW PRES 13N130W 1012 MB TO 08N140W. SCATTERED MODERATE ISOLATED STRONG WITHIN 120 NM N OF AXIS BETWEEN 92W AND 96W. SCATTERED MODERATE WITHIN 180 S OF AXIS BETWEEN 115W AND 122W. SCATTERED MODERATE WITHIN 90 NM N AND 120 NM S OF AXIS W OF 125W.


...DISCUSSION... 1020 MB HIGH PRES CENTERED NEAR 25N124W EXTENDS A RIDGE AXIS SOUTHEASTWARD TO 17N105W. GENTLE TO MODERATE TRADEWINDS PERSIST OVER WATERS BETWEEN THE RIDGE AND N OF THE MONSOON TROUGH. A COLD FRONT LIES TO THE W OF THE HIGH FROM 30N125W TO 23N140W. EARLIER ASCAT SATELLITE PASSES INDICATED MODERATE TO FRESH BREEZES NEAR THE FRONT LIKELY IN NW SWELL. A JASON-2 PASS REVEALED SEAS ABOVE 8 FT BEHIND THE FRONT. THE FRONT WILL WEAKEN THROUGH SUN MORNING BEFORE DISSIPATING...AND THE AFOREMENTIONED HIGH PRES SYSTEM WILL MERGE WITH THE LARGER SUBTROPICAL HIGH TO THE NW. THE NW SWELL CURRENTLY BEHIND THE FRONT WILL OUTRUN IT LATER TODAY AND BRING SEAS IN THE 8-14 FT RANGE TO MUCH OF THE AREA N OF 20N W OF 115W THROUGH MON MORNING.

SEVERAL AREAS OF WEAK LOW PRES ARE NOTED ALONG THE MONSOON TROUGH. CONVECTION IS MOST PREVALENT NEAR THE WESTERN LOW PRES SYSTEM NEAR 13N130W...ENHANCED IN PART BY UPPER TROUGHING W OF THE AREA AND THE FACT THAT THE LOW IS UNDER THE REAR RIGHT QUADRANT OF AN UPPER JET ON THE EASTERN SIDE OF THE UPPER TROUGH.

FARTHER EAST...BROAD UPPER LEVEL DIVERGENCE EXTENDS OVER THE EASTERN WATERS BETWEEN AN ANTICYCLONE CENTERED NEAR IN THE CARIBBEAN NEAR 15N80W AND EASTERLY WINDS ALOFT ALONG THE EQUATOR BETWEEN THE GALAPAGOS AND CENTRAL AMERICA. THERE IS AMPLE MOISTURE HERE...WITH PRECIPITABLE WATER VALUES AROUND 50 MILLIMETERS S OF PANAMA. CONDITIONS SHOULD REMAIN FAVORABLE FOR CONVECTION TO CONTINUE HERE THROUGH SUN AND DIMINISH SOMEWHAT ON MON.

$$ SCHAUER/CHRISTENSEN

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