000
AXPZ20 KNHC 011001
TWDEP 

TROPICAL WEATHER DISCUSSION     
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC MON JAN 01 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0945 UTC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 4N77W 5N93W 6N120W 6N140W. SCATTERED 
MODERATE CONVECTION IS OBSERVED WITHIN 180 NM N OF AXIS W OF 
126W.

...DISCUSSION...

AN UPPER TROUGH ALONG THE W COAST OF THE CONUS CONTINUES SW 
ALONG 32N120W 28N140W TO AN UPPER CYCLONE JUST W OF THE 
DISCUSSION AREA NEAR 13.5N147W. A NARROW BAND OF DRY UPPER AIR 
IS NOTED WITHIN 15 NM OF THE TROUGH TO THE E OF 125W...THEN THE 
BAND WIDENS TO WITHIN 150 NM EITHER SIDE OF LINE 31N132W 27N142W 
THEN INTO THE W SEMICIRCLE OF THE UPPER CYCLONE. A REFLECTION OF 
THE CYCLONE IS ANALYZED AT THE SURFACE AS AN N-S TROUGH FROM 
7N145W TO 16N140W.  

A PAIR OF UPPER ANTICYCLONES ARE NOTED AT 10.5N113.5W AND AT 
10N118W. THE ASSOCIATED UPPER RIDGE LIES ALONG 20N140W 28N130W 
TO 20N118W WHERE THE UPPER FLOW BECOMES CYCLONIC INTO A SECOND 
UPPER TROUGH THAT LIES ALONG 32N96W 23N108W TO A BASE AT 
17N111W. UPPER DIFFLUENCE UNDER THE RIDGE IS ENHANCING ITCZ 
CONVECTION BETWEEN 116W AND 138W. THE RESULTANT DEBRIS MOISTURE 
SPREADS N UNDER THE UPPER RIDGE WITH A MOISTURE PLUME LYING E OF 
THE UPPER TROUGH WITHIN 150 NM EITHER SIDE OF LINE 26N125W 
32N115W...AND CONTINUING NNE ACROSS THE DESERT SW OF THE CONUS. 
DRY UPPER AIR ACCOMPANIES THE UPPER TROUGH OVER OLD 
MEXICO...ROUGHLY N OF 18N BETWEEN 116W AND 101W...WITH A BAND OF 
DRY AIR CONTINUING NE ACROSS SE TX INTO THE MISSISSIPPI DELTA OF 
THE CONUS.  

AN UPPER TROUGH LIES OVER THE TROPICAL E PAC FROM 11N82W TO NEAR 
THE EQUATOR AT 90W. WEAK UPPER RIDGING IS NOTED BOTH SIDES OF 
THIS TROUGH WITH DRY AIR INDICATED OVER MOST OF THE AREA S OF 
17N E OF 105W. THE EASTERN RIDGE IS ENHANCING A FEW CONVECTIVE 
CLUSTERS ALONG THE ITCZ E OF 87W. 

GAP WINDS...SURFACE OBSERVATIONS AT THE ISTHMUS OF TEHUANTEPEC 
LATE SUN WHERE IN THE 20-25 KT RANGE. LATEST MODEL GUIDANCE ALL 
SUGGEST THAT A MINIMAL GULF OF TEHUANTEPEC GALE SHOULD BEGIN 
AFTER SUNRISE MON AND CONTINUE TO JUST AFTER SUNRISE WED. GULF 
OF PAPAGAYO...BRISK ELY WINDS OVER W CARIBBEAN SEA CONTINUE TO 
SUPPORT NE-E WINDS IN THE AND JUST SW OF GULF OF PAPAGAYO.
LATEST MODEL GUIDANCE INDICATES THAT THE WINDS MAY INCREASE TO 
30 KT AND CONTINUE INTO LATE IN THE WEEK. N WINDS EXPECTED TO 
INTERMITTENTLY SURGE TO 20 KT IN THE GULF OF PANAMA BUT SEAS 
SHOULD REMAIN LESS THAN 8 FT WITH SOME SW SWELL.

$$
NELSON