000
AXPZ20 KNHC 212218
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC THU NOV 21 2013

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 
2115 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...       
MONSOON TROUGH EXTENDS FROM 9N84W TO 7N113W...WHERE IT 
TRANSITIONS TO ITCZ CONTINUING ON TO 06N126W TO 6N140W. 
SCATTERED MODERATE ISOLATED STRONG CONVECTION NOTED WITHIN 
150 NM N OF ITCZ W OF 125W.

...DISCUSSION...                                              A 
WEAKENING TUTT LOW WAS CENTERED NEAR 16N130W...AND BEING NUDGED 
SLOWLY E-SE...WITH MIDDLE TO UPPER LEVEL TROUGH EXTENDING SW TO 
09N148W...WHILE REMAINING WEAKLY CONNECTED TO LINGERING MIDDLE 
TO UPPER TROUGH EXTENDING E-NE TO BROAD TROUGH N OF 15N ALONG 
ABOUT 108W. A SHARPENING UPPER LEVEL RIDGE IS NW OF THE CYCLONIC 
CIRCULATION...WITH BROAD EQUATORIAL RIDGE SE OF TUTT LOW W OF 
100W. A VIGOROUS SHORT WAVE TROUGH WAS SWEEPING ACROSS NE 
PORTIONS AND ADJACENT OFFSHORE CALIFORNIA WATERS...WITH AN 85-
100 KT JETSTREAK WORKING THROUGH THE BASE OF THE TROUGH ALONG 
124W. 

AT THE SURFACE...WEAKENING HIGH PRES RIDGE ACROSS NW PORTIONS OF 
THE AREA HAS COLLAPSED WITH THE APPROACH OF TWO FRONTAL TROUGHS 
SINKING S INTO NE AND N CENTRAL PORTIONS...THE FIRST FROM 
28N137W TO WEAK LOW PRES ACROSS FAR N BAJA CALIFORNIA...AND THE 
SECOND BOUNDARY JUST ENTERING N PORTIONS ALONG 30N. FRESH 
NORTHERLY FLOW OCCURRING N OF THE SECOND BOUNDARY WILL PUSH IT S 
TO NEAR 26N BY SAT AFTERNOON...ACCOMPANIED BY BUILDING NORTHERLY 
SWELL RAISING SEAS TO 8 TO 12 FT BY SAT. 
 
ALTHOUGH THE SURFACE HIGH CENTER HAS COLLAPSED...A BROAD AND 
WEAK RIDGE PERSISTS ACROSS N PORTIONS OF THE AREA...FROM THE NW 
CORNER TO NEAR 18N109W. THERE IS ENOUGH OF A PRES GRADIENT 
BETWEEN THE RIDGE AND THE ITCZ TO SUPPORT NELY WINDS AROUND 20 
KT WITH 9 FT ELY SWELLS 10N TO THE ITCZ AND W OF 134W. WINDS 
WILL DECREASE TO 20 KT OR LESS WITH SEA LESS THAN 8 FT EARLY FRI.

A STRONG COLD FRONT IS EXPECTED TO MOVE ACROSS THE GULF OF 
MEXICO ON FRI AND WILL BEGIN TIGHTEN THE PRES GRADIENT ACROSS 
SOUTHERN MEXICO...AND INDUCE NLY WINDS FUNNELING THROUGH THE 
CHIVELAS PASS AND ACROSS THE GULF OF TEHUANTEPEC TO PRODUCE THE 
NEXT SIGNIFICANT GAP WIND EVENT. NORTHERLY WINDS OVER THE GULF 
OF TEHUANTEPEC ARE EXPECTED TO REACH 20-25 KT BY EARLY SAT 
MORNING...AND THEN REACH GALE FORCE BY LATE SAT NIGHT INTO SUN. 

$$
STRIPLING