000
AXPZ20 KNHC 221605
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC TUE FEB 22 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 
1430 UTC.

...ITCZ...

FROM 05N77W TO 02N83W TO 03N90W THEN CONTINUES FROM 05N113W TO 
03N126W TO 04N130W TO 03N140W. SCATTERED MODERATE RAINSHOWERS
FROM 03N TO 06N BETWEEN 117W TO 137W.

...DISCUSSION...

BROAD UPPER LEVEL ANTICYCLONIC FLOW COVERS THE AREA...WITH
A RIDGE EXTENDING FROM THE ISTHMUS OF TEHUANTEPEC TO 06N108W
TO 08N134W AT THE START OF THE 48 HOUR TIME PERIOD...TO
A CONTINUED RIDGE THAT IS FORECAST TO EXTEND FROM THE
SOUTHWESTERN GULF OF MEXICO TO 17N102W ALONG THE MEXICO COAST
TO 10N114W BEYOND 08N140W AT 48 HOURS. THE UPPER LEVEL TROUGH
THAT IS STEERING THE CURRENT COLD FRONT THAT IS IN THE AREA

INTO 
THE EASTERN PACIFIC OCEANTHE LONGWAVE UPPER PATTERN IS EXPECTED 
TO CHANGE LITTLE DURING THE  OVER THE NEXT TWO DAYS AND FEATURES 
AN UPPER TROUGH WITH MEAN AXIS ALONG 125W BOOKENDED BY RIDGING 
WITH THE EASTERN RIDGE LYING OVER THE FORECAST AREA ALONG 
94W/95W AND THE WESTERN RIDGE W OF THE AREA ALONG 145W. AN AREA 
OF MID LEVEL MOISTURE IS BEING ADVECTED TO THE N-NE AHEAD OF THE 
UPPER TROUGH AXIS BY A 20-40 KT SOUTHERLY JET ALOFT. 
PRECIPITABLE WATER VALUES ARE HIGHEST ALONG THE ITCZ W OF 
120W...BUT CONFLUENT FLOW ON THE BACKSIDE OF THE TROUGH IS 
INHIBITING THE DEVELOPMENT OF DEEP CONVECTION THERE.

FARTHER NW AND N...HIGH PRES DOMINATES AT THE SURFACE. RIDGING 
EXTENDS INTO THE AREA THROUGH 32N140W TO 25N120W TO 20N110W. THE 
PRES GRADIENT BETWEEN THE ANOMALOUSLY SOUTHERN ITCZ AND THE 
RIDGING N OF IT IS MAINTAINING FRESH TRADE WINDS AS FAR S AS 
05N. THE AREA OF TRADES IS EXPECTED TO GRADUALLY RETREAT 
WESTWARD THROUGH WED MORNING AS THE SURFACE RIDGING IS 
COMPROMISED BY AN APPROACHING DEEP LAYERED LOW AND COLD FRONT. 
CURRENTLY...THIS VIGOROUS DEEP LAYERED LOW LOCATED OFF THE 
CALIFORNIA COAST NEAR 34N126W IS DROPPING SWD AT 25-30 KT. ITS 
ASSOCIATED COLD FRONT IS EXPECTED TO SWEEP INTO THE FAR N 
PORTIONS OF THE DISCUSSION AREA ALONG 30N125W TO 28N127W TO 
30N138W JUST BEFORE SUNRISE THIS MORNING AND EXTEND FROM 1014 MB 
LOW PRES NEAR 28N121W TO 24N124W TO 26N140W BY EARLY WED MORNING 
BEFORE GRADUALLY DISSIPATING THROUGH WED NIGHT. THIS FRONT WILL 
USHER IN NORTHERLY WINDS OF 20 TO 30 KT WITH SEAS BUILDING 8 TO 
16 FT LATER TODAY. 

GAP WINDS...
THE GULF OF PAPAGAYO...FRESH NORTHEASTERLY TRADE WINDS WILL
CONTINUE TO SPILL FROM THE WESTERN CARIBBEAN SEA INTO THE GULF
OF PAPAGAYO WITH 20 KT WINDS MOST PREVALENT DURING THE EARLY 
MORNING HOURS WHEN THE NIGHTTIME MOUNTAIN DRAINAGE FLOW IS AT
A MAXIMUM.

THE GULF OF PANAMA...THE SURFACE PRESSURE GRADIENT ACROSS
NORTHWESTERN COLOMBIA WILL CONTINUE TO BE TIGHT ENOUGH IN ORDER
TO SUPPORT FRESH NORTHERLY WINDS FOR THE NEXT 36 HOURS. 

$$
MT