000
AXPZ20 KNHC 291528
TWDEP 

TROPICAL WEATHER DISCUSSION     
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC MON JAN 29 2007

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 
1500 UTC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 2N78W 7N92W 4N105W 6N118W 8N140W. 
SCATTERED MODERATE CONVECTION WITHIN 45 NM OF AXIS BETWEEN 
90W-96W.   
    
...DISCUSSION...

THE REX BLOCK ALONG THE W COAST OF THE U.S. CONTINUES THIS 
MORNING WITH A DEEP-LAYERED CUT-OFF LOW CENTERED ABOUT 300 NM 
WNW OF LOS ANGELES CALIFORNIA AND A RIDGE/HIGH OFF THE ALASKAN 
PANHANDLE. BROAD CYCLONIC UPPER FLOW PERSISTS OVER THE 
SUBTROPICAL WATERS ON THE S SIDE OF THE BLOCK WITH THE 
SUBTROPICAL JET AXIS FROM 28N140W TO 22N117W TO NEAR EL PASO 
TEXAS. TODAY THE ASSOCIATED BAND OF MOISTURE/HIGH CLOUDINESS 
EXTENDS SE OF A LINE FROM LA PAZ MEXICO TO CHIHUAHUA...RUNNING 
ACROSS MUCH OF N/CENTRAL MEXICO. THE MID/UPPER LOW HAS PRODUCED 
A 1016 MB SURFACE LOW OFF THE CALIFORNIA COAST WITH TROUGHING 
EXTENDING DOWN TO 28N...WHICH HAS CAUSED AN INTERRUPTION IN THE 
NORMALLY STRONG RIDGE/TRADE WIND REGIME. A DISSIPATING LOW W OF 
THE AREA NEAR 24N142W IS ALSO CONTRIBUTING TO THIS WEAK FLOW 
PATTERN. THE OVERALL BLOCKING PATTERN IS EXPECTED TO LAST FOR 
ANOTHER DAY OR SO...BUT THEN SHOULD GRADUALLY BREAK FREE AS AN 
ENORMOUS TROUGH N OF HAWAII ERODES THE UPPER RIDGE NEAR ALASKA.

QUIET WEATHER IS IN PLACE ALONG THE COAST FROM ACAPULCO SWD TO 
PANAMA AND COLOMBIA. THE MID-LEVEL RIDGE IS ENTRENCHED FROM THE 
CARIBBEAN WWD ACROSS HONDURAS AND GUATEMALA EXTENDING TO 10N110W 
AND THE AREA OF MODERATE/STRONG SUBSIDENCE IS FAR-REACHING E OF 
110W. SLIGHT UPPER DIFFLUENCE SW OF TEHUANTEPEC IS PROBABLY 
HELPING TO SPUR A FEW SHOWERS/TSTMS ALONG THE ITCZ BETWEEN 
90W-96W BUT OTHERWISE THE ENVIRONMENT IS NOT CONDUCIVE FOR 
WIDESPREAD SHOWERS.

A GALE CONTINUES OVER THE GULF OF TEHUANTEPEC...BUT THE 
UNEXPECTED PART IS THAT THE MORNING QUIKSCAT PASS CAME IN WITH 
50 KT VECTORS IN THE CORE OF THE SWATH. THIS EPISODE HAS SHOWN 
THAT THE NAM DID A MUCH BETTER JOB WITH THE INTENSITY OF THE 
EVENT...SO THE WARNING HAS BEEN EXTENDED TO EXPIRE TOMORROW 
MORNING INSTEAD OF THIS EVENING. UNFORTUNATELY THE GFS APPEARS 
TO HAVE BEEN TOO UNDERDONE. NLY WINDS TO 20 KT WILL CONTINUE 
OVER THE GULF OF PANAMA FOR ANOTHER DAY OR SO. 
CONVERSELY...THERE APPEARS TO BE NO END IN SIGHT TO THE 
PERSISTENT 20-25 KT AND OCCASIONAL 30 KT PAPAGAYO WINDS.

$$
BERG