Home


000
AXPZ20 KNHC 302154
TWDEP

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC THU OCT 30 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... TROPICAL DEPRESSION TWENTY-ONE-E IS UPGRADED TO TROPICAL STORM VANCE AT 30/2100 UTC. THIS IS THE 20TH NAMED STORM OF THE TROPICAL SEASON. AT THIS TIME...IT IS CENTERED NEAR 11.0N 101.0W OR ABOUT 360 NM...665 KM S OF ACAPULCO MEXICO MOVING W OR 260 DEGREES AT 4 KT. A TURN TOWARD THE WEST-SOUTHWEST IS FORECAST LATER TODAY...WITH A SOUTHWESTWARD MOTION EXPECTED ON FRIDAY. VANCE SHOULD TURN BACK TOWARD THE WEST ON SATURDAY. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1005 MB. MAXIMUM SUSTAINED WIND SPEED IS 35 KT WITH GUSTS TO 45 KT. SOME STRENGTHENING IS FORECAST DURING THE NEXT 48 HOURS AND THE INTENSITY FORECAST CALLS FOR VANCE REACHING HURRICANE STATUS ON SUN. NUMEROUS MODERATE TO STRONG CONVECTION IS NOTED WITHIN 120 NM NE SEMICIRCLE OF THE STORM CENTER. NUMEROUS MODERATE ISOLATED STRONG CONVECTION IS ALSO IN A BAND FROM 09N TO 10N BETWEEN 101W AND 104W. SCATTERED MODERATE ISOLATED STRONG CONVECTION CAN BE FOUND ELSEWHERE FROM 09N TO 11N BETWEEN 96W AND 100W. SEE LATEST NHC FORECAST/ ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP1/WTPZ21 KNHC FOR MORE DETAILS.

A GALE WARNING WILL GO INTO EFFECT FOR THE GULF OF TEHUANTEPEC STARTING AT 01/0000 UTC. A COLD FRONT IS FORECAST TO MOVE ACROSS THE GULF OF MEXICO THROUGH FRI AND HELP TO INITIATE A NEW ROUND OF NORTHERLY FLOW THROUGH THE CHIVELA PASS INTO THE GULF OF TEHUANTEPEC WITH WINDS REACHING GALE FORCE FRI EVENING. EXPECT BUILDING SEAS OF 12-16 FT WITH THE STRONGEST WINDS BY EARLY SAT. THIS GALE FORCE WIND EVENT IS FORECAST TO PERSIST THROUGH LATE SUN MORNING.


...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... MONSOON TROUGH EXTENDS FROM 09N84W TO 10N98W THEN RESUMES W OF T.S. VANCE FROM 10N105W TO 12N123W TO 10N132W. ITCZ AXIS CONTINUES FROM 10N132W TO 09N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED N OF 03N E OF 82W...INCLUDING THE GULF OF PANAMA. SIMILAR CONVECTION IS FROM 04N TO 08N BETWEEN 82W AND 93W. SCATTERED MODERATE CONVECTION IS FROM 10N TO 14N BETWEEN 119W AND 126W.


...DISCUSSION... A COLD FRONT IS OVER THE NW CORNER OF THE AREA AND EXTENDS FROM FROM 30N135W TO 27N140W. THE FRONT IS FORECAST TO REACH A POSITION FROM 30N125W TO 26N130W TO 23N140W BY FRI AFTERNOON WHILE IT BEGINS TO WEAKEN W OF 130W. BY THAT TIME...MODERATE TO FRESH WINDS WILL PREVAIL NW OF THE FRONT WITH A NEW SET OF NW SWELL BEGINNING TO SPREAD ACROSS THE NW PART OF THE FORECAST AREA. THEREAFTER...BY LATE FRIDAY INTO EARLY SATURDAY...MODERATE TO STRONG HIGH PRES IN THE WAKE OF THE FRONT WILL BRING AN INCREASE IN WINDS AND SEAS ACROSS THE WEST-CENTRAL WATERS. MARINE GUIDANCE SUGGEST A LARGE AREA OF FRESH TO STRONG NE TO E WINDS FROM 13N TO 20N W OF 132W WITH SEAS BUILDING TO 9 FT BY EARLY SAT. THE FRONT WILL CONTINUE TO WEAKEN WITH BUILDING SEAS OF 8-12 FT IN NW SWELL NW OF A LINE FROM 30N123W TO 20N135W BY SAT MORNING.

WEAK HIGH PRESSURE OF 1020 MB IS CENTERED SE OF THE FRONT NEAR 28N130W WITH A RIDGE AXIS EXTENDING SE TO NEAR 22N115W. THE PRESSURE GRADIENT BETWEEN THIS RIDGE AND LOWER PRESSURE IN THE VICINITY OF THE MONSOON TROUGH/ITCZ IS SUPPORTING MODERATE TO FRESH TRADE WINDS ACROSS THE W WATERS GENERALLY FROM 12N TO 20N W OF 120W.

LOOKING AHEAD...A GULF OF PAPAGAYO GAP WIND EVENT IS EXPECTED EARLY SUN AS THE GULF OF MEXICO STRONG COLD FRONT WILL MOVE INTO AND ACROSS THE WESTERN CARIBBEAN SEA. STRONG NE TO E WINDS ARE FORECASTED WITH SEAS BUILDING TO 9 FT.

$$ GR

Home