000
AXPZ20 KNHC 021551
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SAT FEB 02 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 
1530 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS FROM THE COAST OF CENTRAL AMERICA 
NEAR 09N84W TO 04N90W TO 04N101W...THEN TRANSITIONS TO THE ITCZ 
NEAR 04N101W TO LOW PRES NEAR 09N122W 1010 MB TO 06N140W. NO 
SIGNIFICANT CONVECTION IS NOTED. 

...DISCUSSION...
HIGHLY AMPLIFIED PATTERN IN PLACE ACROSS THE DISCUSSION AREA 
WITH A VERY SHARP NEGATIVELY TILTED UPPER LEVEL TROUGH IN PLACE  
FROM 30N136W SSE THROUGH 20N134W TO 12N130W. A 150 KT NLY POLAR
JETSTREAM ON THE BACK SIDE OF THE TROUGH ALONG 141W/142W WILL 
ALLOW THE TROUGH TO EVOLVE INTO A CUTOFF LOW WHICH IS FORECAST 
BY NWP MODELS TO DROP SOUTHWARD ALONG 140W OVER THE NEXT 48 
HOURS. A QUASI-STATIONARY FRONT FROM 30N138W TO 24N140W WILL 
DISSIPATE TONIGHT INTO A DEVELOPING COMPLEX TROUGH AND LOW OVER 
THE DISCUSSION AREA N OF 20N W OF 130W. THE GRADIENT BETWEEN 
THIS COMPLEX AND HIGH PRES TO THE N WILL ALLOW E WINDS TO 
INCREASE TO 20-25 KT...LOCALLY 30 KT GENERALLY FROM 22N TO 28N W 
OF 130W WITHIN 24 HOURS AND SLOWLY DIMINISHING THEREAFTER. 

HIGHLY DIFFLUENT SSW FLOW E OF THE TROUGH IS ALLOWING FOR 
ABUNDANT TROPICAL MOISTURE TO FLOW NORTHEASTWARD E OF THE TROUGH 
AXIS ACROSS BAJA CALIFORNIA AND NORTHERN MEXICO. A 110-130 KT
JETSTREAM ON THE E SIDE OF THE UPPER TROUGH EXTENDS NORTHWARD 
INTO CALIFORNIA THEN TURNS ANTICYCLONICALLY SE ACROSS THE GREAT 
BASIN AND TEXAS WITHIN AND EAST OF AN UPPER LEVEL RIDGE. STRONG 
SUBSIDENCE WITH DRY AND STABLE AIR AT THE MIDDLE AND UPPER 
LEVELS COVERS THE TROPICS S OF 20N E OF 110W.

WITH TIGHT PRES GRADIENT IN PLACE CONTINUES ACROSS SOUTHERN 
MEXICO AND THE ISTHMUS OF TEHUANTEPEC WITH GALE FORCE WINDS 
OCCURRING IN THE GULF OF TEHUANTEPEC. A 0550 UTC OSCAT PASS
CAPTURED THE GALE EVENT. NWP MODELS SUGGEST THE GALE FORCE WINDS 
WILL PULSE THROUGH THE GULF OF TEHUANTEPEC UNTIL ABOUT 48 HOURS
WITH RAPID WEAKENING OF THE WINDS THEREAFTER.  

NE TO E WINDS OF 20-30 KT ARE FUNNELING INTO THE GULF OF 
PAPAGAYO. THESE WINDS ARE FORECAST TO ONLY SLOWLY SUBSIDE TO 
20-25 KT THROUGH THE NEXT 48 HOURS.  

$$
COBB