000
AXPZ20 KNHC 171552
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC THU FEB 17 2011

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W.

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC.

...ITCZ...
AXIS FROM 04N119W TO 07N129W TO 06N140W. NO SIGNIFICANT 
CONVECTION NOTED.

...DISCUSSION...
A LARGE AMPLITUDE DEEP LAYER LONGWAVE TROUGH IS CENTERED OVER 
THE NE PACIFIC EXTENDING INTO AREA THROUGH 32N126W TO 10N140W. 
THE TROUGH SUPPORTS A DISSIPATING COLD FRONT FROM 30N115W TO 
25N123W MOVING SLOWLY SE AND EXPECTED TO FULLY DISSIPATE OVER 
THE NEXT 24 HOURS AS IT CROSSES THE BAJA PENINSULA. ON THE 
BACKSIDE OF THE UPPER LEVEL TROUGHING N OF THE REGION...A STRONG 
SHORTWAVE IS FORECAST TO DIVE SOUTHWARD THIS AFTERNOON AND 
TONIGHT...USHERING A FAST-MOVING COLD FRONT INTO THE 
NORTHWESTERN FORECAST WATERS. IT IS ANTICIPATED WITH THE 
STRONGER MIDDLE TO UPPER LEVEL FORCING AND ASSOCIATED STRONGER 
SURFACE COLD FRONT THAT SW WINDS AHEAD OF THE BOUNDARY WILL 
REACH TO 20 KT WITH STRONGER 20 TO 25 KT NW WINDS AND LARGE LONG 
PERIOD SWELLS WEST OF THE FRONT RAISING WAVE HEIGHTS TO 16 FT BY 
EARLY FRIDAY. ASSOCIATED FRESH WINDS SHOULD REMAIN GENERALLY N 
OF 25N BUT LARGE SWELLS WILL SPREAD S OF 20N BY LATE FRIDAY INTO 
SATURDAY.
 
A BROAD UPPER LEVEL RIDGE PERSISTS E OF THE TROUGH WITH CREST 
ACROSS NORTHEASTERN MEXICO AND EASTERN TEXAS ALONG 99W THAT 
MAINTAINS A GENERALLY DRY AND STABLE ENVIRONMENT E OF 105W. 
MODEL GUIDANCE NUDGES THE RIDGE AXIS SLIGHTLY EASTWARD WHILE THE 
AXIS BECOMES MORE SW TO NE TILED THROUGH SAT AS SERIES OF SHORT 
WAVES CONTINUE TO MOVE OVER THE RIDGE THROUGH THE FORECAST 
PERIOD AND BEYOND. A MID-LEVEL REFLECTION OF AN ATLANTIC TUTT 
SNAKES W-SW ACROSS THE NW CARIBBEAN AND CENTRAL AMERICA TO A 
WEAK MID-LEVEL CYCLONE NEAR 12N93W...WITH STRONG SUBSIDENCE 
DOMINATING N OF 07N BETWEEN 90W AND 100W.

FRESH TO STRONG NE TRADES GENERALLY ARE EXPECTED TO REMAIN S OF 
12N W OF 125W THROUGH THE PERIOD WITH THE AFOREMENTIONED LARGE 
NW SWELLS PROPAGATING S-SE AND ARRIVING LATER TODAY WITHIN THIS 
AREA OF TRADES.

GAP WINDS...
WINDS IN THE 20 TO 25 KT RANGE ARE EXPECTED TO CONTINUE PULSING 
THROUGH THE GULF OF PAPAGAYO OVER NEXT COUPLE OF DAYS...PEAKING 
PRIMARILY DURING THE EARLY MORNING HOURS.

NORTHEASTERLY FLOW WILL SET UP IN THE SOUTHWESTERN GULF OF 
MEXICO LATE FRIDAY INTO SATURDAY AND ALLOW NORTHERLY WINDS IN 
THE RANGE OF 20 TO 25 KT TO RETURN TO THE GULF OF TEHUANTEPEC.

$$
HUFFMAN