000
AXPZ20 KNHC 201605
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC WED FEB 20 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1545 UTC.

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

THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 04N79W TO 
04N95W TO 06N110W TO 05N121W TO 05N131W TO 06N140W. SCATTERED 
MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 120 NM N OF ITCZ 
BETWEEN 126W-128W...AND ALSO FROM 07N-09N BETWEEN 130W-136W.

...DISCUSSION...

A RATHER VIGOROUS UPPER LEVEL ON THE THE SRN PORTION OF A LARGE
UPPER TROUGH OVER THE WRN CONUS IS MOVING SE ACROSS SRN 
CALIFORNIA. THIS FEATURE SUPPORTS A COLD FRONT THAT EXTENDS FROM 
FAR NRN BAJA CALIFORNIA SW TO 30N130W TO 30N126.5W THEN NW TO 
32N130W. HIGHLY AMPLIFIED DEEP LEVEL RIDGING TO THE W OF THE LOW 
IS REELECTED AS A STRONG STATIONARY 1036 MB HIGH CENTER NW OF 
THE AREA AT 36N150W WITH AN ASSOCIATED RIDGE STRETCHING SEWD 
THROUGH 32N140W TO 25N130W TO NEAR 23N118W. WATER VAPOR IMAGERY 
DEPICTS A RATHER BROAD AREA OF MID TO UPPER LEVEL LOW PRES WELL 
W OF THE DISCUSSION AREA NE OF THE HAWAIIAN ISLANDS NEAR 
24N150W. A VERY MOIST AND DIVERGENT MID/UPPER LEVEL SW FLOW 
BETWEEN THIS FEATURE AND THE UPPER TROUGH OVER THE WRN CONUS IS 
ADVECTING AMPLE DEEP ATMOSPHERIC MOISTURE ENE ACROSS THE AREA W 
OF ABOUT 130W. THE SRN LEG OF THIS MOSITURE IS CONFINED TO S OF 
24N BETWEEN 118W AND 130W. E OF 118W THE MOISTURE PLUME THINS 
OUT...BUT ENOUGH OF IT REMAINS TO REACH TO OVER CENTRAL 
MEXICO...AND NE TO ACROSS THE WRN GULF OF MEXICO. PATCHES OF 
RAIN ALONG WITH SCATTERED SHOWERS ARE POSSIBLE OVER THE WRN PART 
OF THE AREA FROM 10N TO 30N W OF 133W. SCATTERED SHOWERS AND 
ISOLATED TSTMS ARE MORE PROBABLE S OF 24N BETWEEN 118W AND 130W 
WHERE UPPER LEVEL JET DYNAMICS COME MORE INTO PLAY.

THE AFOREMENTIONED COLD FRONT WILL QUICKLY MOVE ESE TO JUST 
E OF THE AREA BY THU MORNING WHILE DISSIPATING. THE VERY TIGHT
PRES GRADIENT IN ITS WAKE IS LEADING TO NW-N WINDS OF 20-25 KT
AS WAS SUGGESTED BY AN ASCAT PASS FROM LAST NIGHT. LARGE SEAS OF 
12-16 FT IN NW SWELLS ARE FOLLOWING IN BEHIND THE FRONT. S OF 
THE FRONT TO 25N AND E OF 121W...WINDS ARE W-NW AT 20-25 KT WITH 
SEAS THERE OF 10-12 FT IN NW-N SWELLS. WINDS OVER THE NE PORTION 
OF THE AREA WILL GRADUALLY DIMINISH THROUGH FRI. THESE LARGE
SWELLS WILL ALLOW FOR SEAS OF ABOUT 9-11 FT ALSO BY FRI. FRESH 
TO STRONG SW TO W WINDS WILL PRECEDE THE FRONT OVER THE NORTHERN 
PORTION OF THE GULF OF CALIFORNIA N OF 29N...HOWEVER THESE WINDS 
WILL DIMINISH BY LATE TONIGHT AS THE FRONT UNDERGOES WEAKENING.
 
GAP WINDS...
FRESH TO STRONG WINDS WILL CONTINUE TO PULSE IN THE GULF OF 
PAPAGAYO...WITH THE STRONGEST WINDS OCCURRING DURING THE 
OVERNIGHT AND EARLY MORNING HOURS WITH ENHANCEMENT BY NOCTURNAL 
DRAINAGE FLOW. ASSOCIATED SIGNIFICANT WAVE HEIGHTS WILL PEAK TO 
AROUND 9 FT. THE WINDS OF 20-30 KT THROUGH THIS AREA WILL 
DIMINISH TO 20-25 KT BY EARLY THU AND VARY LITTLE INTO FRI.
 
HIGH PRES OVER EASTERN MEXICO AND LOWERING PRES S OF THE GULF OF 
TEHUANTEPEC WILL PRODUCE ENOUGH OF A PRES GRADIENT ACROSS THE 
ISTHMUS OF TEHUANTEPEC TO SUPPORT A BRIEF PULSE OF 20 TO 25 KT 
GAP WINDS THROUGH THIS MORNING BEFORE DIMINISHING TO LESS THAN
20 KT THIS AFTERNOON.

$$
AGUIRRE