000 AXPZ20 KNHC 111546 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC SAT JAN 11 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1545 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS WSW FROM THE COAST OF COLOMBIA AT 08N78W TO 07N91W WHERE SCATTEROMETER WINDS INDICATE A TRANSITION TO AN ITCZ. THE ITCZ CONTINUES SW TO 05N105W...THEN TURNS WNW TO 07N127W...THEN W TO BEYOND 06N140W. ISOLATED MODERATE CONVECTION IS NOTED WITHIN 240 NM S OF THE MONSOON TROUGH TO THE E OF 83W. SCATTERED MODERATE CONVECTION IS OBSERVED ALONG THE ITCZ WITHIN 30 NM EITHER SIDE OF LINES FROM 08N97W TO 05N104W AND FROM 05N114W TO 06N121W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED ALONG THE ITCZ WITHIN 90 NM EITHER SIDE OF A LINE FROM 07N123W TO 07N134W TO 06N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED WELL N OF THE ITCZ WITHIN 75 NM OF 12N113W...ENHANCED BY UPPER DIFFLUENCE DESCRIBED BELOW. ...DISCUSSION... ALOFT...AN UPPER CYCLONE IS CENTERED OVER THE SOUTHERN TIP OF THE BAJA CALIFORNIA PENINSULA WITH AN UPPER TROUGH EXTENDING S TO A BASE 07N113W. AN UPPER SHORTWAVE RIDGE DOMINATES THE WESTERN PORTION OF DISCUSSION AREA WITH THE RIDGE AXIS ROUGHLY FROM 08N125W TO 30N135W. UPPER MOISTURE IS NOTED WITHIN 270 NM EITHER SIDE OF THIS UPPER RIDGE AXIS. A UPPER TROUGH IS NOTED NW OF THE DISCUSSION AREA AND IS ADVANCING SE. DENSE UPPER MOISTURE IS NOTED WITHIN 300 NM SE OF THIS APPROACHING TROUGH...WITH THE UPPER SOUTHWESTERLY FLOW TAPPING THE MOISTURE ALONG THE NORTHERN PORTION OF THE UPPER RIDGE...RESULTING IN A VERY DENSE PLUME ADVECTED NE ACROSS CENTRAL CALIFORNIA. SOME OF THE MOISTURE IS JUST BEGINNING TO RETURN SE ACROSS THE NORTHERN BAJA PENINSULA IN RESPONSE TO THE UPPER CYCLONE PREVIOUSLY DESCRIBED. WEAK UPPER DIFFLUENCE ALONG THE SOUTHERN PORTION OF THE UPPER RIDGE IS IN PHASE WITH THE LOWER LEVEL ITCZ AND IS ENHANCING THE PREVIOUSLY MENTIONED CONVECTION ALONG THE ITCZ. THE DEBRIS MOISTURE IS ADVECTED E ALONG THE BASE OF THE UPPER TROUGH...THEN TURNS NE TAPPING THE DEBRIS MOISTURE FROM THE CONVECTIVE CLUSTER NEAR 12N113W...CONCENTRATING INTO 180 NM WIDE TROPICAL PLUME THAT CONTINUES NE ACROSS CENTRAL OLD MEXICO...THEN TURNING NE ACROSS THE GULF MEXICO AND EVENTUALLY FEEDING INTO AN INTENSE LINE OF FRONTAL CONVECTION ADVANCING E ACROSS MISSISSIPPI AND NW GEORGIA. AN LARGE UPPER ANTICYCLONE IS OBSERVED OVER THE CARIBBEAN AT 16N75W WITH ITS ANTICYCLONIC ENVELOPE DOMINATING THE DISCUSSION AREA E OF 100W...AND SUPPRESSING CONVECTION ALONG THE MONSOON TROUGH AND ITCZ EXCEPT AS PREVIOUSLY NOTED. THE UPPER CYCLONE OVER THE SOUTHERN TIP OF THE BAJA PENINSULA WILL DRIFT SLOWLY E TONIGHT...THEN LIFT QUICKLY NE ON SUN LOSING IDENTITY IN A DEEP LAYERED TROUGH THAT WILL DOMINATE CENTRAL N AMERICA EARLY NEXT WEEK. THE UPPER SHORTWAVE RIDGE CURRENTLY OVER THE WESTERN PORTION WILL AMPLIFY NE INTO A LONGWAVE RIDGE THAT WILL SHIFT E OVER THE EASTERN N PACIFIC IN THE WAKE OF THE LONGWAVE TROUGH SETTING UP OVER THE CENTRAL N AMERICA. THE CARIBBEAN ANTICYCLONE WILL DISSOLVE INTO A BROAD ANTICYCLONE THAT WILL CONTINUE TO DOMINATE THE EASTERN PORTION OF THE DISCUSSION AREA. AT LOWER LEVELS...A 1027 MB HIGH IS CENTERED AT 32N130W WITH A RIDGE EXTENDING SE TO 17N105W. NE-E 20-25 KT TRADES ARE ENHANCED SW OF THE RIDGE FROM 09-12N BETWEEN 130-135W WITH SEAS 7-10 FT. MIXING LONG PERIOD NW AND CROSS EQUATORIAL SE TRADE WILL ADDITIONALLY MIX WITH NE WIND WAVES RESULTING IN COMBINED SEAS OF 7-10 FT ACROSS THE AREA N OF THE ITCZ AND TO W OF 117W. A COLD FRONT WILL SWEEP E ACROSS THE WATERS JUST N OF THE DISCUSSION AREA AND JUST DIP INTO THE NE CORNER TONIGHT...THEN PASS THROUGH THE NORTHERN GULF OF CALIFORNIA ON SUN. POST- FRONTAL HIGH PRESSURE WILL INCREASE NE WINDS TO 20-25 KT ACROSS THE WATERS N OF 25N W OF 117W ON SUN INTO EARLY MON...WITH SEAS OF 8-14 FT FROM 25-32N. THE GRADIENT WILL BEGIN TO RELAX ON MON AFTERNOON. GULF OF CALIFORNIA...NORTHERLY 10-15 KT WINDS WILL PERSIST TILL LATE TONIGHT...THEN BECOME NORTHERLY 5-10 KT S OF 29N AND SOUTHERLY 5 KT ACROSS THE WATERS N OF 29N. EXPECT ONLY A 10 KT SW-W-NW WIND SHIFT WITH THE COLD FRONT PASSAGE ON SUN AND SUN NIGHT. STRENGTHENING POST-FRONTAL HIGH PRESSURE WILL INCREASE THE NW FLOW TO 20-25 KT ACROSS THE GULF WATERS N OF 29N BY LATE SUN NIGHT...WITH THESE CONDITIONS SPREADING SE ACROSS THE ENTIRE GULF BY LATE MON. LITTLE CHANGE EXPECTED THROUGH LATE TUE NIGHT AS SEAS BUILD TO 7 FT IN LONG NW-SE FETCH ACROSS THE CENTRAL WATERS. THE GRADIENT WILL RELAX SUPPORTING 10-1 5KT AGAIN BY EARLY THU. GAP WINDS... GULF OF TEHUANTEPEC...LIGHT NORTHERLY WINDS THIS MORNING WILL BECOME LIGHT AND VARIABLE LATE THIS AFTERNOON. A NORTHERLY DRAINAGE SURGE OF 20-30 KT IS EXPECTED AGAIN BRIEFLY LATE TONIGHT INTO EARLY SUN MORNING...HEN GRADUALLY DIMINISHING TO 10- 15 KT BY LATE SUN AFTERNOON. THE DIURNAL MAXIMUM DRAINAGE SHOULD ONLY BE 15-20 KT LATE SUN NIGHT. THE POST-FRONTAL GRADIENT WILL SUPPORT 20-30 KT BEGINNING MON NIGHT...INCREASING TO MINIMAL GALE BY SUNRISE TUE...AND AT LEAST STRONG GALE WINDS IF NOT MINIMAL STORM CONDITIONS BY LATE WED. BEST GUESS FOR NOW IS THIS NEXT GALE EVENT WILL PERSIST THROUGH MIDDAY ON THU BEFORE DIMINISHING BELOW GALE FORCE. GULF OF PAPAGAYO...FRESH EASTERLY TRADES ACROSS THE WESTERN CARIBBEAN ARE SPILLING ACROSS CENTRAL AMERICA MAINTAINING LATE NIGHT NE-E SURGES OF 20-25 KT THROUGH...AND DOWNSTREAM OF THE GULF OF PAPAGAYO. LITTLE CHANGE EXPECTED THROUGH LATE THU NIGHT. $$ NELSON