000
AXPZ20 KNHC 080929
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC FRI FEB 08 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0730 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
THE MONSOON TROUGH AXIS WAS ANALYZED FROM 04N77W TO 04N81W TO 
03N88W TO 09N110W. THE ITCZ AXIS WAS ANALYZED FROM 09N110W TO 
09N115W THEN CONTINUES FROM 06N122W TO 07N140W. A TROUGH WAS 
ANALYZED FROM 09N117W TO 03N120W. SCATTERED MODERATE CONVECTION 
WAS NOTED WITHIN 75 NM ON EITHER SIDE OF THIS TROUGH N OF 05N. 
THIS TROUGH COINCIDES WITH A LOCAL MAXIMUM OF PRECIPITABLE WATER 
AS WELL AS WITH A SLOW MOVING MID-LEVEL TROUGH. THIS TROUGH WILL 
REMAIN A FOCUS FOR PRECIPITATION THE NEXT FEW DAYS.

...DISCUSSION...
A ZONAL UPPER JET IS IN PLACE FROM 20N TO 30N AND WILL CHANGE 
LITTLE IN POSITION OVER THE NEXT FEW DAYS. AN UPPER TROUGH OVER 
CALIFORNIA AND NE FORECAST WATERS WILL AMPLIFY SLIGHTLY AS IT 
PASSES SOUTHEASTWARD INTO NW MEXICO TODAY. NEW NORTHERN STREAM 
ENERGY MOVING INTO THE WESTERN SIDE OF THIS TROUGH WILL FLATTEN 
IT OVER THE FORECAST AREA OVER THE WEEKEND. A COLD FRONT 
ASSOCIATED WITH THIS TROUGH ALOFT CURRENTLY LIES FROM 32N120W TO 
28N128W TO 30N140W. THIS FRONT WILL SWEEP THROUGH BAJA 
CALIFORNIA NORTE BY TONIGHT...BRINGING FRESH TO STRONG NW WINDS 
TO BOTH SIDES OF THE PENINSULA N OF 27N TONIGHT THROUGH SAT 
AFTERNOON...WITH SEAS TO 12 FT IN NW SWELL IN THE PACIFIC 
WATERS. 

THE 1035 MB SUBTROPICAL HIGH NEAR 38N140W IS FORECAST TO WEAKEN 
SLIGHTLY AS IT MOVES NORTHEASTWARD. THIS WILL RELAX THE PRESSURE 
GRADIENT BETWEEN THE SUBTROPICAL RIDGE AND THE ITCZ... 
DIMINISHING THE FRESH TO STRONG TRADE WINDS OVER WESTERN WATERS 
TO A FRESH NE BREEZE BY LATE SAT. 

GAP WINDS...
GULF OF TEHUANTEPEC...A FRESH TO STRONG N BREEZE WILL BRIEFLY 
MOVE THROUGH CHIVELA PASS AND INTO THE GULF OF TEHUANTEPEC 
OVERNIGHT TONIGHT...ENDING BY SAT AFTERNOON. THE 0326 UTC ASCAT 
PASS SHOWS LIGHT N WINDS IN THE GULF OF MEXICO OFF THE COAST OF 
VERACRUZ W OF THE WEAK STATIONARY FRONT ANALYZED APPROXIMATELY 
90 NM OFFSHORE. THIS FRONT SHOULD RECEIVE A REINFORCING SHOT OF 
COLD AIR AS A SECOND FRONT MAKES ITS WAYS THROUGH THE WESTERN 
GULF LATER TODAY. WINDS WILL TURN SOUTHEASTERLY IN THE SW GULF 
OF MEXICO BY 1800 UTC SAT...CUTTING OFF THE FLOW THROUGH CHIVELA 
PASS.

GULF OF PAPAGAYO...THE INCREASED PRESSURE GRADIENT BETWEEN THE 
MONSOON TROUGH TO THE S AND HIGH PRESSURE MOVING INTO THE 
NORTHERN GULF OF MEXICO OVERNIGHT TONIGHT WILL INCREASE THE NE 
TRADE WIND FLOW THROUGH CENTRAL AMERICA TO A FRESH TO STRONG 
BREEZE IN THE GULF OF PAPAGAYO BEGINNING EARLY SAT MORNING. 
THESE WINDS WILL CONTINUE TO PULSE TO 25 KT THROUGH THE 
WEEKEND...WITH THE STRONGEST WINDS EXPECTED IN THE EARLY MORNING 
HOURS WHEN DRAINAGE FLOW OFF THE LAND IS AT A MAXIMUM.

$$
SCHAUER