000 AXPZ20 KNHC 060331 TWDEP AXPZ20 KNHC DDHHMM TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC THU FEB 06 2014 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0315 UTC. ...SPECIAL FEATURE... GULF OF TEHUANTEPEC...A NOCTURNAL NORTHERLY 20-25 KT SURGE WILL BEGIN AROUND MIDNIGHT TONIGHT AND CONTINUE THROUGH THU EVENING. MODEL GUIDANCE IS MORE AGGRESSIVE THE PAST RUN AND THE FORECAST HAS BEEN ADJUSTED FOR A GALE WARNING OF 30-35 KT BEGINNING AROUND MIDNIGHT ON THU NIGHT. THE GALE IS EXPECTED TO PERSIST THROUGH LATE FRI MORNING WITH THE NORTHERLY FLOW DIMINISHING SIGNIFICANTLY ON FRI EVENING. THE DRAINAGE FLOW WILL INCREASE AGAIN LATE FRI NIGHT WITH 20-25 KT EXPECTED THROUGH SAT EVENING. THE SAT NIGHT DRAINAGE IS EXPECTED TO BE STRONGER SUPPORTING 20- 30 KT THROUGH LATE MON MORNING. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS W FROM THE NW COAST OF COLOMBIA AT 09N76W TO ACROSS NORTHERN COSTA RICA TO THE PACIFIC COAST OF COSTA RICA AT 10N85W...THEN TURNS SW THROUGH 06N88W TO 04N96W WHERE SCATTEROMETER WINDS INDICATE A TRANSITION TO AN ITCZ WHICH CONTINUES W-NW TO 08N120W...THEN W TO BEYOND 07.5N140W. A 60 NM WIDE CLUSTER OF SCATTERED MODERATE CONVECTION IS NOTED NEAR 04N82W. ISOLATED MODERATE CONVECTION IS NOTED WITHIN 60 NM EITHER SIDE OF A LINE FROM 03N86W TO 05N95W TO 05N103W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS OBSERVED ALONG THE ITCZ WITHIN 240 NM OF 08N117W. ISOLATED MODERATE CONVECTION IS OBSERVED ELSEWHERE WITHIN 75 NM OF THE ITCZ BETWEEN 120-129W. ...DISCUSSION... AN UPPER LONGWAVE TROUGH DOMINATES CENTRAL N AMERICA WITH AN EMBEDDED SHORTWAVE TROUGH MOVING THROUGH THE PATTERN. THIS SHORTWAVE TROUGH ENTERS THE DISCUSSION AREA AT 32N107W AND CONTINUES SW ACROSS THE SOUTHERN GULF OF CALIFORNIA AND ACROSS THE SOUTHERN BAJA CALIFORNIA PENINSULA TO A BASE AT 23N112W. FURTHER S AN UPPER CYCLONE IS CENTERED NEAR 18N129W WITH AN UPPER TROUGH EXTENDING S TO A SECOND...BUT ILL-DEFINED UPPER CYCLONE NEAR 11N133W. AN UPPER ANTICYCLONE IS IMMEDIATELY TO THE E NEAR 11N116W WITH A SHORTWAVE RIDGE EXTENDING NW TO AN ERODING CREST AT 23N120W. ALTHOUGH ERODING...THIS RIDGE WILL STILL PREVENT THE UPPER SHORTWAVE TROUGH FROM PICKING UP THE CYCLONE AT 19N128W AND IT WILL REMAIN CUT OFF AND DRIFTING SW FOR A FEW MORE DAYS. THESE FEATURES COMBINE TO SET UP AN AREA OF UPPER DIFFLUENCE ENHANCING CONVECTION PREVIOUSLY DESCRIBED ALONG THE ITCZ. THE RESULTANT DEBRIS MOISTURE IS ADVECTED N UNDER THE SHORTWAVE RIDGE...THEN TURNS E ALONG 20N...AND LATER NE IN RESPONSE TO THE SHORTWAVE TROUGH...CONCENTRATING INTO A DENSE 270 NM WIDE TROPICAL PLUME STREAMING NE ACROSS THE SOUTHERN TIP OF THE BAJA PENINSULA AND THE SOUTHERN GULF OF CALIFORNIA... ACROSS NORTHERN OLD MEXICO...EVENTUALLY MERGING WITH ADDITIONAL MOISTURE OVER THE SOUTHERN CONUS. THE E PORTION OF THE DISCUSSION AREA IS DOMINATED BY A BROAD UPPER RIDGE ORIGINATING FROM AN UPPER ANTICYCLONE AT 05N78W WITH THE MAIN RIDGE AXIS EXTENDING N ACROSS THE WESTERN CARIBBEAN... THEN TURNING NE ACROSS THE BAHAMAS...AND EVENTUALLY COLLAPSING OVER ATLANTIC S OF BERMUDA. THE RIDGE IS ACCOMPANIED BY VERY DRY UPPER AIR...EXCEPT FOR SMALL AREA OF DEBRIS MOISTURE FROM PREVIOUS CONVECTION ALONG THE MONSOON TROUGH...WHICH IS NOW STREAMING N ACROSS WESTERN GUATEMALA THE YUCATAN PENINSULA ALONG THE W PERIPHERY OF THE UPPER RIDGE. A SURFACE HIGH IS ANALYZED NEAR 31N131W WITH A LOW LEVEL RIDGE EXTENDING SE TO A FAIRLY SHARP CREST DETECTED BY SCATTEROMETER WINDS AT 12N102W. NORTHERLY WINDS AT 15-20 KT ARE OBSERVED N OF 22N E OF THE RIDGE TO THE PACIFIC COAST OF THE BAJA CALIFORNIA PENINSULA...WITH SEAS OF 5-8 FT IN MIXED NW AND DECAYING CROSS EQUATORIAL SE SWELL. THE SEAS WILL SUBSIDE TO 3-5 FT LATE TONIGHT AS THE NW WINDS DIMINISH TO 10-15 KT...EXCEPT FOR AN EXPECTED NW PULSE OF 15-20 KT ALONG THE CENTRAL PACIFIC COAST OF THE BAJA ON FRI. GUIDANCE IS SUGGESTING THE GRADIENT WILL RELAX SOME ON SAT AS THE WINDS VEER TO THE N IN RESPONSE TO THE SURFACE HIGH SHIFTING E TO NEAR 30N124W. THE GRADIENT WILL TIGHTEN AGAIN SAT NIGHT INTO SUN WITH NW 20-25 KT WINDS NEAR 29N116W BY LATE SUN. THESE 20-25 KT CONDITIONS WILL SPREAD S ALONG THE PACIFIC COAST OF BAJA ON MON THEN THE GRADIENT RELAXES AGAIN ON TUE. GULF OF CALIFORNIA...LIGHT...MOSTLY NW...WINDS AT 5-10 KT WITH SEAS OF 1-2 FT ARE EXPECTED THROUGH EARLY FRI. THE NW WINDS WILL INCREASE TO 10-15 KT ACROSS THE SOUTHERN GULF LATE FRI...AND FURTHER INCREASE TO 15-20 KT ACROSS THE ENTIRE WATERS S OF 29N ON SAT EVENING...WITH LITTLE CHANGE THROUGH SUN NIGHT AS SEAS BUILD TO 6 FT IN LONG FETCH AREAS NEAR 25N. THE GRADIENT WILL RELAX ON MON INTO TUE. GULF OF PAPAGAYO...A NE-E 15-20 KT NOCTURNAL PULSE IS EXPECTED TONIGHT. GUIDANCE SUGGESTS A STRONGER 20-25 KT EVENT WILL OCCUR LATE THU NIGHT THROUGH SUNRISE FRI...THEN ONLY A 15-20 KT EVENT LATE FRI NIGHT INTO EARLY SAT. THE LATE NIGHT DRAINAGE FLOW IS EXPECTED TO INCREASE TO 20-25 KT ON SAT NIGHT AND AGAIN ON SUN NIGHT. $$ NELSON