000
AXPZ20 KNHC 201523
TWDEP 

TROPICAL WEATHER DISCUSSION     
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SAT JAN 20 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 5N90W 4N100W 6N124W 5N140W. 
WIDELY SCATTERED SHOWERS/TSTMS FROM 1N-6N BETWEEN 78W-81W. 
ISOLATED MODERATE CONVECTION WITHIN 45 NM OF 5N90W. 

...DISCUSSION...

A CLOSED 548-DAM LOW AT 500 MB IS SHIFTING E OUT OF ARIZONA AS A 
SHORTWAVE TROUGH PLUNGES SE FROM SOUTHERN CALIFORNIA TO 24N130W. 
THE SUBTROPICAL JET REMAINS ENTRENCHED OVER THE PACIFIC 
WATERS...EXTENDING NE TO SRN BAJA CALIFORNIA THEN TO NEAR EL 
PASO TEXAS. WITH THE WHOLE SYSTEM SLIDING SLOWLY E...UPPER LEVEL 
RIDGING IS BUILDING ALONG 137W WITH A CONTINUING REINFORCEMENT 
OF SURFACE HIGH PRES W OF CALIFORNIA. THE ELY TRADES REMAIN IN 
THE MODERATE TO STRONG RANGE...SUSTAINED TO NEAR 30 KT NEAR 
140W. EVEN THOUGH THERE IS SOME LOW-LEVEL CONVERGENCE AND 
SUFFICIENT MOISTURE ALONG THE ITCZ...THE FLOW ALOFT W OF 110W IS 
PRIMARILY ZONAL SO THERE ARE VERY LITTLE DYNAMICS PRESENT TO 
FOSTER CONVECTION. ALSO...THERE IS SOME DRIER AIR PRESENT IN THE 
MID/UPPER LEVELS OF THE ATMOSPHERE SO THERE IS PROBABLY A SLIGHT 
CAP PROHIBITING DEEP CONVECTIVE DEVELOPMENT.

FARTHER E...A STRONG MID-LEVEL HIGH IS CENTERED NEAR THE 
WINDWARD PASSAGE IN THE CARIBBEAN BUT THIS POSITION IS NOW 
FARTHER E THAN IT HAS BEEN OVER THE PAST WEEK OR SO. THE RIDGE 
IS STILL EXPANSIVE ENOUGH FOR MODERATE/STRONG SUBSIDENCE E OF 
110W. A WEAK UPPER LEVEL SHEAR AXIS EXTENDS FROM THE GULF OF 
TEHUANTEPEC SWD...BUT THE LACK OF DEEP MOISTURE IS NOT CAUSING 
ANY SIGNIFICANT WEATHER. THE GALE OVER TEHUANTEPEC ENDED EARLIER 
OVERNIGHT...AND WINDS WILL QUICKLY FALL BELOW 20 KT BY THIS 
EVENING AS THE HIGH OVER THE GULF OF MEXICO WEAKENS. WINDS OVER 
THE GULFS OF PAPAGAYO AND PANAMA WILL ALSO DIMINISH A BIT OVER 
THE NEXT FEW DAYS.

$$
BERG