000
AXPZ20 KNHC 181516
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
1605 UTC WED FEB 18 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC. 
  
...SPECIAL FEATURES...

GULF OF TEHUANTEPEC GALE WARNING...STRONG SURFACE HIGH PRESSURE 
IS BUILDING INTO SOUTHERN MEXICO BEHIND A COLD FRONT THAT IS 
MOVING ACROSS THE GULF OF MEXICO. THE TIGHT SURFACE PRESSURE  
GRADIENT ALONG WITH A PUSH OF DENSE DRY AND COOL AIR THROUGH THE 
CHIVELA PASS IN SOUTHERN MEXICO IS RESULTING IN GALE-FORCE WINDS 
IN THE GULF OF TEHUANTEPEC RIGHT NOW. THE WINDS WILL DIMINISH TO 
BELOW GALE FORCE AS THE HIGH PRESSURE THAT IS TO THE NORTH OF 
THE AREA WEAKENS AND SHIFTS EASTWARD BY EARLY FRI.
                   
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...

MONSOON TROUGH FROM 10N85W TO 5N90W. ITCZ FROM 5N90W TO 3N110W 
TO 6N130W TO 6N140W. SCATTERED MODERATE ISOLATED STRONG 
CONVECTION FROM 6N-17N BETWEEN 125W-133W.

...DISCUSSION... 

A MIDDLE LEVEL TO UPPER LEVEL TROUGH ACROSS THE NW PORTION OF 
THE AREA EXTENDS FROM 32N136W TO A CYCLONIC CIRCULATION NEAR 
25N131W TO ANOTHER CYCLONIC CIRCULATION AT 20N135W TO 5N132W. A 
110-125 KT NLY JETSTREAM W OF THE TROUGH AXIS ENTERS THE AREA AT 
32N140W TO 17N138W...WITH A 95-110 KT SLY JET E OF THE TROUGH 
AXIS FROM 11N127W TO 28N122W. THE TROUGH WAS SUPPORTING A COLD 
FRONT THAT BECAME A SURFACE TROUGH ALONG 30N137W TO 23N138W. A 
FEW SHOWERS ARE ALONG THE TROUGH. AN UPPER LEVEL RIDGE IS E OF 
THE TROUGH EXTENDING FROM AN ANTICYCLONIC CIRCULATION OFF THE 
COAST OF PANAMA TO NORTHERN BAJA CALIFORNIA.
 
A SURFACE TROUGH IS IN THE ITCZ FROM 11N130W 5N133W. NEARBY 
TRADE WIND FLOW IS AT 15 TO 20 KNOTS. UPPER LEVEL FEATURES WILL 
WEAKEN GRADUALLY BUT REMAIN GENERALLY IN PLACE DURING THE NEXT 
24 TO 48 HOURS. THIS WILL KEEP THE SURFACE TROUGH IN PLACE AS 
WELL.

ELY WINDS 20-25 KT WILL BEGAN TO BLOW THROUGH THE GULF OF 
PAPAGAYO STARTING EARLY THU AND CONTINUE INTO FRI.

$$
DGS