000
AXPZ20 KNHC 132149
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC SUN JAN 13 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...

THE MONSOON TROUGH IS ALONG 05N77W TO 07N87W TO 06N97W. THE 
INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 06N97W TO 
08N119W THEN RESUMES FROM 07N122W TO 06N140W. SCATTERED MODERATE 
CONVECTION IS WITHIN 180 NM N OF THE ITCZ BETWEEN 114W AND 119W.

...DISCUSSION...

STRONG 1043 MB HIGH PRES IS CENTERED NEAR 43N140W WITH A RIDGE 
EXTENDING SE TO NEAR 15N102W. THE PRESSURE GRADIENT BETWEEN THIS 
RIDGE AND LOWER PRESSURE IN THE VICINITY OF THE ITCZ ACROSS THE 
W CENTRAL WATERS IS MAINTAINING FRESH TO STRONG TRADES GENERALLY 
FROM 08N TO 21N AND W OF 120W AS DEPICTED BY THE LATEST 
SCATTEROMETER DATA. THE AREA OF HIGH PRES WILL DRIFT NORTHWARD 
WHILE GRADUALLY WEAKENING OVER THE NEXT COUPLE OF DAYS. THIS 
WILL LOOSEN THE PRESSURE GRADIENT AND DECREASE THE AREAL 
COVERAGE OF THE STRONG TRADEWIND FLOW OVER THE W CENTRAL WATERS 
SIGNIFICANTLY BY MIDWEEK.

A WEAK SURFACE TROUGH IS EMBEDDED IN THE ITCZ FROM 11N119W TO 
06N121 WITH SCATTERED MODERATE CONVECTION PRESENT N OF 07N 
WITHIN 60 NM EITHER SIDE OF THE TROUGH. THIS TROUGH WILL MOVE 
WESTWARD THROUGH THE NEXT FEW DAYS HELPING TO MAINTAIN THE 
TRADES DESCRIBED ABOVE.

GULF OF CALIFORNIA...VERY STRONG HIGH PRES WILL CONTINUE TO 
BUILD ACROSS THE U.S. GREAT BASIN REGION. THIS COMBINED WITH 
WELL DEFINED SURFACE TROUGHING OVER WESTERN MEXICO WILL RESULT 
IN STRONG TO NEAR GALE FORCE NW WINDS DOWN THE ENTIRE LENGTH OF 
THE GULF OF CALIFORNIA BY MON EVENING WITH SEAS UP TO 11 FT 
SPILLING OUT OF THE SOUTHERN GULF. GUIDANCE DEVELOPED AROUND A 
LOCAL RESEARCH STUDY INDICATES AROUND A 25 PERCENT PROBABILITY 
OF GALE CONDITIONS IN THE GULF. WINDS WILL BE CAPPED AT 30 KT IN 
THE FORECAST FOR NOW UNLESS PROBABILITIES FOR 35 KT INCREASE.

GAP WINDS...THE GULF OF PAPAGAYO WILL MAINLY BE MODERATE TO 
FRESH TONIGHT...INCREASING TO FRESH TO STRONG MON NIGHT INTO TUE 
MORNING AS WINDS TO THE E IN THE WESTERN CARIBBEAN SEA INCREASE.

MODERATE TO FRESH NORTHERLY WINDS WILL SEEP INTO THE GULF OF 
PANAMA FROM THE SW CARIBBEAN DURING THE NEXT FEW DAYS. THE WINDS 
MAY BRIEFLY AND LOCALLY INCREASE TO STRONG LEVELS.

LOOKING AHEAD FOR THE GULF OF TEHUANTEPEC...A SURGE OF COLD AIR 
IS FORECAST TO ARRIVE BEHIND A COLD FRONT IN THE GULF OF MEXICO 
WED INTO THU. A PINCHED PRES GRADIENT WILL BE IN PLACE EARLIER 
WED ALLOWING FOR NORTHERLY WINDS TO INCREASE TO FRESH TO STRONG 
AHEAD OF THE ARRIVAL OF THE FRONT. ONCE THE FRONT CLEARS THE SW 
GULF OF MEXICO NORTHERLY WINDS WILL BE FUNNELED THROUGH THE 
CHIVELA PASS ACROSS THE GULF OF TEHUANTEPEC AREA...WITH GALE 
FORCE WINDS POSSIBLE BY LATE WED NIGHT INTO THU. MODEL GUIDANCE 
EVEN HINTS AT MINIMAL STORM FORCE BY LATE THU NIGHT WITH THE WW3 
BUILDING RESULTANT SEAS UP TO 21 FT.

$$
LEWITSKY