000
AXPZ20 KNHC 171518
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SUN FEB 17 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 
1500 UTC.

...SPECIAL FEATURE...
WINDS TO STORM FORCE PERSIST THROUGH THE GULF OF TEHUANTEPEC 
THIS MORNING. THE WINDS ARE THE RESULT OF STRONG 1029 MB HIGH 
PRES IN THE GULF MEXICO ACCOMPANIED BY A PUSH OF COLD AIR 
THROUGH INTO THE GULF TEHUANTEPEC. THE HIGH PRES SHIFTS WELL 
EAST ACROSS THE NORTHERN GULF OF MEXICO THROUGH THIS AFTERNOON 
ALLOWING WINDS OVER THE SW GULF OF MEXICO TO VEER MORE TO THE E 
AND SE. THIS WILL ALLOW STORM CONDITIONS TO DIMINISH TO GALE 
FORCE THROUGH THE MORNING. THE COMBINATION OF A STILL HIGH PRES 
GRADIENT ALONG WITH LINGERING COLDER AIR DRAINING INTO THE GULF 
OF TEHUANTEPEC WILL ALLOW THE GALE CONDITIONS TO LAST INTO THE 
EARLY EVENING WITH WINDS TO 30 KT TONIGHT INTO MON MORNING. SEAS 
WILL BUILD AS HIGH AS 20 FT THROUGH AFTERNOON GIVEN THE LONG 
FETCH AND PERSISTENCE OF THE STORM EVENT.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
ITCZ FROM 5N106W 8N127W TO 4N140W. NO SIGNIFICANT CONVECTION.

...DISCUSSION...
AN UPPER LEVEL TROUGH OVER THE FAR NW PORTION OF THE DISCUSSION 
AREA WITH AXIS FROM 32N133W TO 28N140W. DOWNSTREAM A BROAD FLAT 
UPPER LEVEL RIDGE IS N OF 18N E OF 125W. A 75-95 KT JETSTREAM 
ACROSS THE TOP OF THE RIDGE FROM 27N127W TO NORTHERN BAJA 
CALIFORNIA WHERE WINDS INCREASE TO 110 KT. HIGH LEVEL MOISTURE 
IS WITHIN 280 NM S OF THE JET. OTHERWISE MODERATE TO STRONG 
SUBSIDENCE WITH DRY STABLE AIR AT THE MIDDLE AN UPPER LEVELS 
ASSOCIATED WITH THE RIDGE S OF 21N E OF 120W. IN THE DEEP 
TROPICS AN UPPER LEVEL TROUGH EXTENDS FROM 11N115W TO THE 
EQUATOR AT 114W.

SURFACE RIDGE COVERS THE AREA N OF 15N W OF 115W. THE PRES 
GRADIENT ALONG THE SOUTHERN PERIPHERY OF THE RIDGE IS 
SUPPORTING  ELY WINDS IN THE 20-25 KT RANGE FROM 6N-16N W OF 
135W. 

ELY WINDS 20-25 KT CONTINUE TO BLOW THROUGH THE GULF OF PAPAGAYO.
THE WINDS ARE FORECAST TO CONTINUE IN THE 20-25 KT RANGE THROUGH 
AT LEAST TUE.

$$
DGS