000
AXPZ20 KNHC 150924
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC TUE JAN 15 2008

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

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0900 UTC.
 
...ITCZ...

ITCZ AXIS IS CENTERED ALONG 5N77W 6N84W 5N95W 11N120W 7N140W. NO 
SIGNIFICANT CONVECTION.

...DISCUSSION...

N OF 20N...
AN OMEGA-TYPE BLOCKING PATTERN IS IN PLACE BETWEEN NORTHERN 
MEXICO AND THE WATERS N OF HAWAII ALTHOUGH CHANGES ARE EXPECTED 
WITHIN THE NEXT 24-36 HOURS AS A MUCH DEEPER TROUGH DIGS ACROSS 
THE WESTERN UNITED STATES. FOR NOW...A CLOSED MID-LEVEL LOW IS 
CENTERED NEAR 28N109W OVER THE STATE OF SONORA IN MEXICO WHILE 
THE BARELY-CLOSED UPPER LEVEL TROUGH EXTENDS FROM SE NEW MEXICO 
SW ACROSS BAJA CALIFORNIA TO 22N124W. THE SUBTROPICAL JET...WITH 
WIND SPEEDS NEAR 110 KT...LIES ON THE SE SIDE OF THE TROUGH WITH 
TROPICAL MOISTURE IN THE FORM OF BROKEN CIRRUS STREAMING ACROSS 
CENTRAL MEXICO. STRONG SUBSIDENCE ON THE BACK SIDE OF THE UPPER 
TROUGH IS KEEPING SKIES MOSTLY CLEAR ACROSS MUCH OF NW MEXICO 
AND THE WATERS WWD TO 130W. THE RIDGE PORTION OF THE OMEGA 
PATTERN LIES ROUGHLY ALONG 129W AND THEN GIVES WAY TO A 
VERTICALLY STACKED CYCLONE JUST NW OF THE AREA NEAR 31N146W. THE 
OCCLUDED LOW HAS A CENTRAL PRESSURE OF 1004 MB AND THE 
ASSOCIATED FRONT...NOW STATIONARY...EXTENDS S OF THE SYSTEM 
ALONG 142W. LOW CLOUDS WITH ISOLATED SHOWERS LIE MAINLY N OF 25N 
W OF 138W.

S OF 20N...
UPPER LEVELS OVER THE TROPICS ARE DOMINATED BY ONE MAIN 
FEATURE...A DEEP CLOSED LOW NEAR 9N119W. TO THE E OF THE 
LOW...BROAD SW TO WESTERLY 40-60 KT WINDS EXTEND TO SW MEXICO 
AND CENTRAL AMERICA. DIFFLUENCE WITHIN 900 NM NE OF THE 
LOW...BEFORE THE FLOW CONVERGES WITH THE SUBTROPICAL JET...IS 
HELPING TO TRIGGER SCATTERED MODERATE CONVECTION SW OF ACAPULCO 
AND MANZANILLO FROM 10N-17N BETWEEN 102W-117W. IN ADDITION...A 
WEAK SURFACE TROUGH IS LOCATED NEAR 120W AND IS CONTRIBUTING TO 
LOW-LEVEL CONVERGENCE. FARTHER E...DRY AIR AND SUBSIDENCE 
INCREASE E OF 100W AND REACH A MAXIMUM OVER SRN CENTRAL AMERICA 
AND THE W CARIBBEAN. W OF THE TROUGH...BROAD W TO NORTHWESTERLY 
FLOW IS CONVERGING TOWARDS THE LOW AND PRODUCING MORE SUBSIDENCE 
S OF 10N W OF 122W.

$$
BERG