000
AXPZ20 KNHC 122156
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC TUE JAN 12 2010

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

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC.

...ITCZ...
AXIS ANALYZED ALONG 02N78W TO 04N104W TO 06N116W TO 06N125W TO 
07N140W. SCATTERED MODERATE CONVECTION WAS NOTED WITHIN 250 NM N 
OF THE AXIS BETWEEN 108W AND 116W AND WITHIN 90 NM S OF THE AXIS 
BETWEEN 110W AND 120W. SCATTERED MODERATE AND ISOLATED STRONG 
CONVECTION WAS NOTED WITHIN 150 NM EITHER SIDE OF THE AXIS W OF 
138W.

...DISCUSSION...
AN EXPANSIVE UPPER LEVEL RIDGE EXTENDS FROM 31N130W TO 10N130W 
WITH A VERY DRY AND STABLE AIR MASS ACROSS THE AREA W OF 110W. A 
100 TO 140 KT JETSTREAM ENTERS THE AREA NEAR 30N132W EXTENDING 
TO THE SE WHERE WINDS DECREASE TO 90 TO 100 KT NEAR 21N112W. 
UPPER LEVEL DIFFLUENT FLOW BETWEEN THE RIDGE AND AN UPPER LEVEL 
CYCLONIC CIRCULATION W OF THE DISCUSSION AREA IS ENHANCING 
CONVECTION ALONG THE ITCZ W OF 138W. AN UPPER LEVEL TROUGH 
EXTENDS SW FROM AN UPPER LEVEL LOW NEAR THE BIG BEND OF TEXAS TO 
NEAR PUERTO VALLARTA MEXICO TO THE ITCZ NEAR 06N120W. A 95 TO 
105 KT JETSTREAM IS SE OF THE TROUGH AXIS ADVECTING ABUNDANT 
TROPICAL MOISTURE FROM THE ITCZ TO THE NE ACROSS CENTRAL MEXICO 
AND INTO THE WESTERN GULF OF MEXICO AND BAY OF CAMPECHE. AN 
UPPER LEVEL ANTICYCLONIC CIRCULATION IS CENTERED NEAR 05N83W 
WITH A RIDGE AXIS EXTENDING ACROSS CENTRAL AMERICA TO THE 
YUCATAN PENINSULA.

AT THE SURFACE...A DISSIPATING COLD FRONT EXTENDS FROM 30N137W 
TO 27N140W. A BAND OF BROKEN/OVERCAST CLOUDS IS WITHIN 75 NM E 
OF THE FRONT. A 1021 MB SURFACE HIGH IS CENTERED E OF THE FRONT 
NEAR 29N121W. A RIDGE EXTENDS FROM THE HIGH TO NEAR 20N131W. 
FLOW AROUND THE SOUTHERN PORTION OF THIS RIDGE IS PRODUCING 20 
TO 25 KT TRADES FROM 08N TO 14N W OF 117W. A COUPLE OF SURFACE 
TROUGHS ARE EMBEDDED WITHIN THE ITCZ...ONE EXTENDING FROM 
09N104W TO 02N106W AND ANOTHER TO THE W EXTENDING FROM 10N116W 
TO 03N118W. 

A STATIONARY FRONT EXTENDS ACROSS WESTERN PANAMA FROM THE 
CARIBBEAN SEA TO 05N90W WITH A FRONTAL TROUGH EXTENDING FROM 
THERE TO NEAR 06N103W. SCATTERED MODERATE CONVECTION WAS NOTED 
WITHIN 210 NM N OF THE FRONT BETWEEN 88W AND 93W...WITH 
SCATTERED MODERATE AND ISOLATED STRONG CONVECTION NOTED WITHIN 
150 NM N OF THE FRONTAL TROUGH BETWEEN 100W AND 103W.

...GAP WINDS...
GULF OF TEHUANTEPEC...A TIGHT PRES GRADIENT ALONG THE SE COAST 
OF MEXICO CONTINUES TO PRODUCE MINIMAL GALE FORCE WINDS. THE 
GRADIENT WILL WEAKEN ON WED AND WINDS WILL DIMINISH TO LESS THAN 
GALE FORCE WITHIN 36 HOURS.

GULF OF PAPAGAYO...MODERATE TO STRONG GALE FORCE WINDS PERSIST 
IN THE GULF OF PAPAGAYO AND DOWNWIND TO 09N90W AS CAPTURED BY AN 
EARLIER 1140 UTC WINDSAT SCATTEROMETER PASS. WINDS WILL 
GRADUALLY DIMINISH TO LESS THAN GALE FORCE WITHIN THE NEXT 36 
HOURS.

GULF OF PANAMA...20 TO 25 KT NORTHERLY WINDS ARE BLOWING S FROM 
THE SW CARIBBEAN SEA ACROSS THE ISTHMUS OF PANAMA AND DOWNWIND 
OVER THE GULF OF PANAMA TO 03N BETWEEN 79W AND 82W. THESE WINDS 
ARE EXPECTED TO CONTINUE DURING THE NEXT 48 HOURS AS A TIGHT 
PRES GRADIENT REMAINS IN PLACE DUE TO LOW PRES OVER NE COLOMBIA.

FOR ADDITIONAL INFORMATION PLEASE VISIT 
HTTP://WWW.HURRICANES.GOV/MARINE

$$
LEWITSKY