000
AXPZ20 KNHC 281516
TWDEP 

TROPICAL WEATHER DISCUSSION     
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SUN JAN 28 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 1N78W 6N89W 3N100W 7N125W 7N140W. 
SCATTERED MODERATE CONVECTION WITHIN 75 NM OF AXIS BETWEEN 
121W-125W.

...DISCUSSION...

A REX BLOCK IS ONCE AGAIN IN PLACE ALONG THE W COAST OF THE U.S. 
WITH A CUT-OFF MID/UPPER LOW CENTERED NEAR SAN FRANCISCO...AND 
AN OVERLYING RIDGE PENETRATING INLAND ACROSS WRN WASHINGTON. 
BENEATH THE BLOCK...A SHORTWAVE TROUGH IS ROTATING THROUGH THE 
BASE OF THE LOW FROM 30N125W TO 14N130W. THE SUBTROPICAL 
JET...WITH CORE SPEEDS OF 125 KT...PLUNGES S AROUND THE TROUGH 
THEN TURNS NE COMING ASHORE ACROSS CENTRAL BAJA. UPPER 
DIFFLUENCE DOWNSTREAM OF THE TROUGH IS PRODUCING WIDESPREAD 
MID/HIGH LEVEL CLOUDINESS N OF 10N BETWEEN 105W-122W FLARING NE 
TOWARDS THE W COAST OF MEXICO. A NEARLY STATIONARY 1011 MB LOW 
IS CENTERED NEAR 25N141W BUT NOW THAT ITS UPPER SUPPORT HAS 
PASSED IT BY...IT NO LONGER HARBORS ANY DEEP CONVECTION AND IS 
NOW GENERALLY A SKELETON CIRCULATION WHICH WILL BECOME ABSORBED 
BY A FRONT N OF THE HAWAIIAN ISLANDS.

MID-LATITUDE FLOW CONTINUES TO BYPASS THE FAR E PACIFIC WATERS 
WITH A PERSISTENT RIDGE EXTENDING ACROSS THE CARIBBEAN AND 
CENTRAL AMERICA TO 10N100W. A WEAK TROUGH IS EMBEDDED WITHIN THE 
ITCZ NEAR 91W AND IS LIKELY PRODUCING SCATTERED SHOWERS...BUT 
THERE IS NO DEEP CONVECTION.

A 1236 UTC QUIKSCAT PASS THIS MORNING INDICATES THAT THE GALE 
OVER THE GULF OF TEHUANTEPEC HAS STARTED WITH WINDS ALREADY UP 
TO 40 KT. THE FORECAST CALLS FOR WINDS TO INCREASE ADDITIONALLY 
TO 45 KT AS HIGH PRES CONTINUES TO BUILD OVER THE GULF OF 
MEXICO...ALTHOUGH THERE IS A POSSIBILITY THAT WINDS COULD REACH 
STORM FORCE (50 KT) IN ABOUT 12 HRS OR SO. SINCE THESE WINDS ARE 
NOT EXPECTED TO REMAINED SUSTAINED AT THAT LEVEL FOR MORE THAN 
6-12 HRS...THE WARNING WILL REMAIN AS A 45 KT GALE. WINDS ARE 
EXPECTED TO DROP BELOW GALE BY MON EVENING...OR 36 HRS.

$$
BERG