000
AXPZ20 KNHC 190931
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SAT MAR 19 2016

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
0900 UTC.              
 
...SPECIAL FEATURES...                                         
A COLD FRONT CURRENTLY ACROSS SE TEXAS IS EXPECTED TO MOVE S-SE
ACROSS THE WESTERN GULF OF MEXICO AND BY EARLY SUN MORNING PASS
EAST OF THE CHIVELA PASS. BUILDING HIGH PRESSURE BEHIND THE
FRONT WILL INDUCE A GULF OF TEHUANTEPEC GAP WIND EVENT. UPDATED
GRIDS INDICATE GALE FORCE CONDITIONS TO BEGIN MID-AFTERNOON SUN
AND QUICKLY RAMP UP TO PEAK WINDS OF 40 TO 45 KT LATE SUN NIGHT
INTO MON MORNING IN ASSOCIATED WITH MAXIMUM NOCTURNAL DRAINAGE
EFFECTS. SEAS WILL BUILD RAPIDLY AS WELL AFTER THE ONSET OF
NORTHERLY WINDS REACHING 15 TO 19 FT MON. SEE LATEST NWS HIGH
SEAS FORECAST UNDER AWIPS/WMO HEADERS MIAHSFEP2/FZPN03 KNHC FOR
MORE DETAILS.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...            
THE ITCZ EXTENDS FROM 06N93W TO 04N116W TO 04N140W. ISOLATED
MODERATE CONVECTION IS WITHIN 120 NM EITHER SIDE OF A LINE FROM
05N85W TO 07N91W TO 06N99W...AND FROM 03N TO 07N BETWEEN 127W
AND 136W. SCATTERED MODERATE CONVECTION IS S OF 01S W OF 118W.

...DISCUSSION...                                             
WATER VAPOR IMAGERY INDICATES AN UPPER LEVEL SHORTWAVE TROUGH IN
THE VICINITY OF 35N147W ROTATING AROUND THE SOUTHERN PERIPHERY
OF A DEEP LAYERED NORTH PACIFIC LOW CENTERED NEAR 46N151W. THE
SHORTWAVE SUPPORTS A COLD FRONT THAT REMAINS TO THE NW OF THE
DISCUSSION AREA...HOWEVER REMNANTS FROM A PREVIOUS SHORTWAVE
CURRENTLY EXTEND AS A STATIONARY FRONT FROM 31N131W TO BEYOND
26N140W. THE STATIONARY FRONT IS EXPECTED TO GRADUALLY WEAKEN
THROUGH SAT AFTERNOON AS THE APPROACHING COLD FRONT IS FORECAST
TO MERGE WITH ANY REMAINING ENERGY LATE SAT NIGHT INTO EARLY SUN
MORNING. LATEST GLOBAL MODELS SUGGEST A MAJORITY OF WINDS
GREATER THAN THE 20 KT THRESHOLD FOR HIGH SEAS INCLUSION TO
REMAIN N OF 30N AND THE PRIMARY IMPACT ACROSS THE DISCUSSION
WATERS BEING THE NEW PULSE OF NORTHWESTERLY SWELL THAT
ACCOMPANIES THE FRONT. EXISTING NW SWELL OF 8 TO 13 FT
ASSOCIATED WITH THE STATIONARY FRONT WILL PROPAGATE S-SE AND
GRADUALLY BEGIN TO SUBSIDE THROUGH SUN...HOWEVER THE APPROACHING
FRONT WILL ONCE AGAIN BUILD SEAS INTO A 11 TO 17 FT RANGE ACROSS
THE NORTHWESTERN WATERS BY OVERNIGHT SUN INTO EARLY MON.

ELSEWHERE AT THE SURFACE...A 1020 MB HIGH IS CENTERED NEAR
28N130W WITH A RIDGE AXIS EXTENDING SE TO NEAR 12N100W. THE
OVERALL PRESSURE GRADIENT BETWEEN THE RIDGE AND LOWER PRES TO
THE S WITHIN THE ITCZ REGION IS SUPPORTING MODERATE TO
OCCASIONAL FRESH NE TRADES S OF 18N AND W OF 120W...WITH SEAS
RANGING 5-8 FT.

BEYOND 48 HOURS...A GULF OF PAPAGAYO GAP WIND EVENT WITH 20-25
KT NE WINDS IS SUGGESTED BY MODEL GUIDANCE TO BRIEFLY TAKE PLACE
MON MORNING AND LIKELY PULSE EACH MORNING THROUGH THU.

$$
HUFFMAN