000 AXPZ20 KNHC 020917 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC FRI JAN 02 2009 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... THE INTERTROPICAL CONVERGENCE ZONE WAS ALONG THE LINE...04N77W TO 03N83W TO 06N9100W TO 11N119W TO 06N134W TO 06N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION WITHIN 150 NM N OF AXIS BETWEEN 117W AND 121W. NUMEROUS MODERATE SCATTERED STRONG CONVECTION WITHIN 120 NM N AND 150 NM S OF AXIS BETWEEN 122W AND 129W. ...DISCUSSION... A PROGRESSIVE BUT VIGOROUS NORTHERN STREAM SHORTWAVE TROUGH DARTING THROUGH THE GREAT LAKES REGION WILL BE REPLACED WITH SHORTWAVE RIDGING FORECAST TO BUILD OVER THE CENTRAL STATES TODAY. THE MID-LEVEL RIDGING IN THE WAKE OF THE SHORTWAVE HAS CAUSED THE WESTERN END OF THE GULF FRONT OVER THE GULF OF MEXICO TO LIFT NORTH AS A WARM FRONT...WITH LOW-LEVEL RIDGING N OF THE FRONT ALREADY SHIFTING TO THE E INTO THE WESTERN ATLANTIC. THIS CHANGEABLE PATTERN OVER THE CONUS HAS RESULTED IN FALLING PRESSURES OVER NORTHERN MEXICO AND THE WESTERN GULF...WHICH IN TURN IS HELPING TO END THE LATEST GULF OF TEHUANTEPEC GALE WIND EVENT. ALTHOUGH THE EVENT IS IN THE MIDST OF WINDING DOWN...A 0319 UTC ASCAT PASS SUGGESTED 20 TO 25 KT WITHIN ABOUT 45 NM EITHER SIDE OF A LINE FROM THE GULF OF TEHUANTEPEC TO 15N95W. GIVEN THE INHERENT LOW BIAS IN ASCAT WIND VECTORS...PEAK WINDS OF 30 KT ARE STILL LIKELY NEAR AND DIRECTLY DOWNWIND OF THE GULF OF TEHUANTEPEC AT THIS HOUR...BUT THESE WINDS SHOULD BEGIN DECREASING FURTHER THROUGHOUT THE DAY. THE NARROW FETCH WIDTH...TAKEN WITH THE DURATION OF THIS EVENT...SHOULD YIELD WAVE HEIGHTS OF 8 TO 9 FT STILL DOWNWIND OF TEHUANTEPEC...WITH NE TO E SWELL PROPAGATING WELL DOWNSTREAM FROM THE REGION. AS DEEPER LOW PRESSURE FORMS OVER MEXICO OVER THE NEXT DAY OR TWO...THE EVENT SHOULD COME TO A CLOSE. ELSEWHERE...FOR WELL MORE THAN A WEEK NOW GAP WINDS NEAR AND DOWNSTREAM OF THE GULF OF PAPAGAYO HAVE BEEN BLOWING. A QUIKSCAT PASS FROM EARLIER YESTERDAY EVENING SUGGESTED THAT THE EVENT IS BARELY HANGING ON WITH NE 20 KT WINDS NOW CONFINED TO ABOUT 30 NM EITHER SIDE OF 11N BETWEEN THE COAST AND 87W. WAVE HEIGHTS ARE ESTIMATED TO STILL PEAK AROUND 8 OR 9 FT IN THE AREA FROM 10N TO 12N E OF 90W. A HEALTHY LOW-LEVEL RIDGE NORTH OF THE GULF FRONT RETREATING IN THE GULF OF MEXICO FAVORS AN ENHANCED PRESSURE GRADIENT FROM THE WESTERN ATLANTIC INTO THE WESTERN CARIBBEAN AND CENTRAL AMERICA. AS A RESULT...MODEL GUIDANCE INSISTS THAT THE CURRENT GULF OF PAPAGAYO GAP WIND EVENT WILL CONTINUE UNABATED FOR AT LEAST A FEW MORE DAYS. OTHERWISE...A WEAK SHORTWAVE TROUGH IN THE SOUTHERN STREAM EXTENDS FROM THE DESERT SOUTHWEST TO AROUND 21N138W. THE MAIN SHORTWAVE IS FORECAST TO MOVE INTO THE SOUTHERN PLAINS WITHIN 24 HOURS...WHILE ADDITIONAL SHORTWAVE ENERGY DIVES INTO WHAT SHOULD BE THE BEGINNING OF ANOTHER WESTERN TROUGH. SEVERAL EASTERLY PERTURBATIONS TRACKING ACROSS THE TROPICAL EAST PACIFIC ARE INTERACTING WITH THE MID-LATITUDE WESTERLIES DIPPING SOUTHWARD OVER THE REGION. RESULTING FROM THIS IS ENHANCED CONVECTION OVER A BROAD REGION FROM 07N TO 13N BETWEEN 110W AND 130W. OVER THE NEXT FEW DAYS...MODEL SUGGEST THAT THE ITCZ SHOULD BE DRAWN NORTHWARD AS LOW PRESSURE CONSOLIDATES IN THE VICINITY OF 12N122W AND MOVES LITTLE. EXPECT LOCALLY STRONG WINDS AND HIGHER SEAS NEAR THIS FEATURE...IN ADDITION TO THE POSSIBILITY OF ENHANCED CONVECTIVE ACTIVITY. FINALLY...ENHANCED LOW-LEVEL SUBTROPICAL RIDGING NEAR 32N140W SHOULD BE REINFORCED THE NEXT FEW DAYS...AS THE NEXT SHORTWAVE IN A SERIES DEPOSITS ANOTHER MODESTLY STRONG SURFACE RIDGE OVER THE SUBTROPICAL NORTHEAST PACIFIC. THIS SHOULD KEEP THE ALREADY ENHANCED TRADES GENERALLY OVER AN AREA FROM 11N TO 22N W OF 130W IN PLACE...WITH SEAS OF 9 TO 13 FT IN A MIXTURE OF SW AND NW SWELL...AS WELL AS NE WIND WAVES. NE WINDS TO 20 KT SHOULD COVER AN EVEN LARGER EXPANSE AS FAR E AS 115W...THOUGH THIS AREA SHOULD CONTRACT TO THE WEST BY THE WEEKEND. OTHERWISE...OUTSIDE OF AREAS OF ENHANCED TRADES...EVERYWHERE W OF A LINE FROM ROUGHLY 30N118W TO 00N102W SHOULD SEE SEAS OF UP TO 9 FT IN LONG PERIOD NW SWELL N OF 10N AND SW SWELL S OF 10N. $$ KIMBERLAIN