000
AXPZ20 KNHC 241557
TWDEP 

TROPICAL WEATHER DISCUSSION                                  
NWS NATIONAL HURRICANE CENTER MIAMI FL                      
1605 UTC TUE NOV 24 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
0700 UTC.

...SPECIAL FEATURES...                

TROPICAL STORM SANDRA WAS CENTERED NEAR 11.2N 106.1W AT 24/1500
UTC MOVING W OR 280 DEGREES AT 11 KT. ESTIMATED MINIMUM CENTRAL
PRESSURE WAS 1000 MB. MAXIMUM SUSTAINED WIND SPEED WAS 45 KT
WITH GUSTS TO 55 KT. NUMEROUS MODERATE TO STRONG CONVECTION WAS
WITHIN 210 NM N SEMICIRCLE AND 30 NM S SEMICIRCLE. A DECREASE IN
FORWARD SPEED IS EXPECTED OVER THE NEXT COUPLE OF DAYS...WITH A
TURN TOWARD THE NW FORECAST BY WED AS SANDRA INTENSIFIES TO
HURRICANE STRENGTH. SEE THE LATEST NHC FORECAST/ADVISORY UNDER
AWIPS/WMO HEADERS MIATCMEP2/WTPZ22 KNHC FOR MORE DETAILS.

GULF OF TEHUANTEPEC STORM WARNING...A STRONG COLD FRONT THAT
MOVED THROUGH THE CHIVELA PASS YESTERDAY HAS ALLOWED FOR
COOL...DRY AIR TO MOVE OVER THE RELATIVELY WARM WATERS OF THE
GULF OF TEHUANTEPEC. WINDS WERE REACHING STORM FORCE THROUGH
EARLY THIS MORNING...AND GALE CONDITIONS WILL PERSIST THROUGH
EARLY WED THEN DIMINISH SLIGHTLY THROUGH LATE WED...BEFORE
INCREASING AGAIN TO GALE FORCE WED NIGHT/EARLY THU DURING THE
PERIOD OF PEAK NOCTURNAL DRAINAGE. 

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

THE MONSOON TROUGH AXIS WAS ANALYZED FROM 05N77W TO
11N101W...THEN CONTINUES FROM 07N110W TO 06N115W TO 06N118W.
ITCZ AXIS FROM 06N118W TO 09N130W TO 09N135W. SCATTERED MODERATE
CONVECTION WAS NOTED WITHIN 120 NM EITHER SIDE OF MONSOON TROUGH
E OF 81W...AND BETWEEN 90W AND 95W. SCATTERED MODERATE
CONVECTION WAS ALSO NOTED WITHIN 120 NM N AND 180 NM S OF ITCZ
BETWEEN 125W AND 135W.

...DISCUSSION...

N OF 15N E OF 120W...A DEEP LAYER TROUGH IS DIGGING ACROSS THE
FAR NE PACIFIC AND MOVING ONSHORE OVER THE WEST COAST OF THE
UNITED STATES. AN ASSOCIATED SURFACE TROUGH WILL SHIFT EAST
ACROSS BAJA CALIFORNIA NORTE AND THE NORTHERN PORTION OF THE
GULF OF CALIFORNIA LATE TONIGHT THROUGH WED. WESTERLY WINDS WILL
FUNNEL THROUGH LOWER LYING GAPS ACROSS BAJA CALIFORNIA NORTE AND
INTO THE NORTHERN GULF OF CALIFORNIA TONIGHT AND EARLY WED AHEAD
OF THE TROUGH. A COLD FRONT WILL FOLLOW...MOVING INTO THE WATERS
OFF BAJA CALIFORNIA NORTE AND THE NORTHERN GULF OF CALIFORNIA BY
LATE WED. THIS WILL BE ACCOMPANIED BY FRESH NW WINDS AND LONG
PERIOD NW SWELL TO 9 FT. THE LEADING EDGE OF THE SWELL WILL
REACH GUADALUPE ISLAND BY LATE WED...AND THE NORTHERN COAST OF
BAJA CALIFORNIA SUR BY EARLY THU. MEANWHILE THE OUTER EDGE OF
MIXED SWELL IN EXCESS OF 8 FT ASSOCIATED WITH THE APPROACHING
SANDRA WILL MOVE NORTH OF THE REVILLAGIGEDO ISLANDS WED
NIGHT...FOLLOWED BY THE OUTER PERIPHERY OF STRONG WINDS AHEAD OF
SANDRA BY LATE THU. LOOKING AHEAD...SANDRA WITH ACCOMPANYING
STRONG WINDS AND HIGH SEAS WILL SHIFT N TO NE AHEAD OF THE
STALLING FRONT...GRAZING THE LOS CABOS AREA FRI INTO SAT BEFORE
SHIFTING ACROSS THE MOUTH OF THE GULF OF CALIFORNIA AND PUSHING
INLAND NORTH OF MAZATLAN BY LATE SAT.

S OF 15N E OF 110W...A TIGHT PRES PATTERN BETWEEN HIGH PRES OVER
THE SOUTHEAST UNITED STATES AND THE MONSOON TROUGH TO THE S HAS
SET UP ACROSS CENTRAL AMERICA. A FRESH TO STRONG E-NE BREEZE
HAVE BEEN OCCURRING DOWNWIND OF THE GULF OF PAPAGAYO WITH THE
ASSISTANCE OF NOCTURNAL DRAINAGE FLOW EARLIER THIS MORNING.
THESE WINDS WILL SHIFT AWAY FROM THE COAST THROUGH THE REMAINDER
OF THE AFTERNOON AND DIMINISH AT NIGHT BEFORE REPEATING THE
PATTERN BEGINNING EARLY WED MORNING. WEAKER GAP WIND FLOW IS
EXPECTED EARLY THU...ALTHOUGH SEAS TO 8 FT STILL CAN BE RULED
OUT DOWNSTREAM OF PAPAGAYO THROUGH THU MORNING. ELSEWHERE SW
SWELL WILL MOVE ACROSS THE EQUATOR AND MIX WITH SHORTER PERIOD
NE SWELL EMERGING OUT OF TEHUANTEPEC.

ELSEWHERE...THE 1008 MB POST-TROPICAL REMNANT LOW RICK WAS
LOCATED NEAR 21N123W. THERE IS NO SIGNIFICANT DEEP CONVECTION
ASSOCIATED WITH THE LOW. STRONG UPPER LEVEL SOUTHWEST WINDS ARE
EXPECTED TO REMAIN OVER THE SYSTEM FOR THE NEXT TWO DAYS. A
FRESH BREEZE IS BELIEVED TO PERSIST NEAR THE SURFACE LOW THIS
MORNING...BUT WILL DIMINISH THROUGH THE AFTERNOON AS THE LOW
OPENS UP TO A TROUGH BY TONIGHT AS THE SYSTEM MOVES SLOWLY TO
THE NW. MEANWHILE HIGH PRES OVER THE EASTERN NORTH PACIFIC HAS
BEEN DISPLACED TO THE N NEAR 50N145W. TRADES CONTINUES TO BE A
GENTLE TO MODERATE BREEZE ACCORDING TO THE RECENT SCATTEROMETER
PASSES. A COLD FRONT IS FORECAST TO REACH FAR N WATERS OVERNIGHT
TONIGHT...WITH N-NW WINDS EXPECTED TO REACH 20-25 KT BEHIND THE
FRONT OVER FAR NE WATERS BY EARLY WED MORNING. NW SWELL
ASSOCIATED WITH THIS SYSTEM WILL PROPAGATE INTO THE AREA AHEAD
OF THE FRONT...WITH SEAS IN THE 7-9 FT RANGE EXPECTED OVER
WATERS N OF 28N BETWEEN 118W AND 133W BY EARLY WED MORNING. SEAS
WILL REACH AS HIGH AS 11 FT THROUGH EARLY THU MORNING AND THE
SWELL PROPAGATES AS FAR S AS 21N124W.

$$
CHRISTENSEN