000 AXPZ20 KNHC 170948 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC MON MAR 17 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0930 UTC. ...SPECIAL FEATURES... A LATE WINTER SEASON STRONG COLD FRONT OVER THE CENTRAL AND SW GULF OF MEXICO WILL QUICKLY MOVE EASTWARD THROUGH TONIGHT. A COOL AND DRY AIR BEHIND THE FRONT WILL SPILL S ACROSS SOUTHEASTERN MEXICO THROUGH THE ISTHMUS OF TEHUANTEPEC...AND TO THE GULF OF TEHUANTEPEC. NLY WINDS OF 20-30 KT ARE EXPECTED TO BLAST QUICKLY THROUGH THE GULF OF TEHUANTEPEC LATER THIS MORNING...AND INCREASE TO GALE FORCE STARTING LATE THIS MORNING OR EARLY THIS AFTERNOON. SEAS THERE ARE FORECAST TO BUILD TO 10 FT BY AROUND NOON...AND TO 14 FT BY LATE MON NIGHT. THIS GALE EVENT WILL BE RATHER SHORT-LIVED AS IT IS EXPECTED TO LAST TO DAYBREAK TUE BEFORE WINDS QUICKLY DIMINISH TO 15-20 KT. SEAS WILL SUBSIDE TO LESS THAN 8 FT BY EARLY TUE AFTERNOON. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... MONSOON TROUGH EXTENDS FROM 10N85W TO 08N94W. ITCZ EXTENDS FROM 04N100W TO 04N112W TO 01N130W WHERE IT IS NO LONGER DEFINED. NO SIGNIFICANT CONVECTION IS NOTED. ...DISCUSSION... A RATHER EXTENSIVE UPPER TROUGH EXTENDS FROM NE TEXAS SW TO ACROSS N CENTRAL MEXICO...AND CONTINUES SW TO AN UPPER LOW BECOMING CUT-OFF WITH TIME AT 16N119W. TO THE W OF THESE FEATURES...HIGHLY AMPLIFIED RIDGING COVERS THE AREA BLOCKING ANY TROUGHS FROM MOVING INTO THE DISCUSSION AREA FOR THE TIME BEING. SATELLITE WATER VAPOR IMAGERY SHOWS AMPLE STRONG SUBSIDENCE COVERING THE THE BULK OF THE CENTRAL AND WESTERN PORTIONS OF THE AREA WITH ASSOCIATED DRY AND STALE ATMOSPHERIC CONDITIONS. MOSTLY CLEAR SKIES ARE SKIES ARE NOTED N OF 16N...WITH THE EXCEPTION OF SCATTERED TO LOCALLY BROKEN LOW CLOUDS MOVING WESTWARD IN THE NE TRADES OVER THE FAR WESTERN PORTION. ATMOSPHERIC INSTABILITY IS CONFINED OVER THE SOUTHERN HALF OF THE AREA TO THE SE AND E OF THE AFOREMENTIONED UPPER TROUGH AND LOW. UPPER LEVEL DIFFLUENCE NOTED TO THE SE OF THE LOW CONTINUES TO PLAY A LARGE ROLE IN SUSTAINING THE INSTABILITY OCCURRING THERE. AS A RESULT...MAINLY OVERCAST MULTILAYERED CLOUDS WITH EMBEDDED SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING FROM 02N TO 16N BETWEEN 106W AND 119W. HIGH LEVEL CLOUDINESS ORIGINATING FROM THIS ACTIVITY IS BEING CHANNELED NEWD BY A STRONG JET STREAM BRANCH THAT ROUNDS THE BASE OF THE UPPER TROUGH NEWD TOWARDS THE CENTRAL SECTION OF MEXICO AS WELL AS THE NW PORTION OF SOUTHEASTERN MEXICO. THE UPPER TROUGH IS FORECAST TO PULL AWAY FROM THE AREA WHILE WEAKENING THROUGH TONIGHT LEAVING BEHIND THE UPPER LOW...WHICH WILL MOVE ESE THROUGH TUE WHILE IT ALSO WEAKENS. EXPECT FOR THE ABOVE DESCRIBED AREA OF CLOUDS AND WEATHER TO GRADUALLY TRANSLATE EASTWARD OVER THE NEXT 48 HOURS...AND DIMINISH IN COVERAGE. HIGH LEVEL CLOUDINESS WILL CONTINUE TO STREAM NEWD TOWARDS MOST OF CENTRAL AND SOUTHEASTERN MEXICO THROUGH THE NEXT 48 HOURS. AT THE SURFACE...BROAD RIDGING STRETCHES INTO THE DISCUSSION AREA THROUGH 32N131W TO 24N122W TO NEAR 14N115W. HIGH PRES COVERS THE AREA N OF 14N W OF 113W. A TROUGH SEPARATES THE MONSOON TROUGH FROM THE ITCZ...AND IT IS ALONG A POSITION FROM 10N94W TO 04N98W. WIDELY SCATTERED SHOWERS AND TSTMS ARE SEEN WITHIN 45 NM OF A LINE FROM 07N91W TO 07N94W TO 07N98W. THIS ACTIVITY IS NOT EXPECTED TO INCREASE MUCH IN COVERAGE OVER THE NEXT 24-48 HOURS AS PRONOUNCED RIDGING IN THE UPPER LEVELS WITH THE ASSOCIATED ANTICYCLONE AT 05N84W MAINTAINS DRY AIR ALOFT IN PLACE. WITH REGARDS TO THE MARINE ASPECT OF THE DISCUSSION AREA...A ZONE OF NE TO E 15-20 KT TRADES IS PRESENT TO THE S AND SW OF THE HIGH PRES RIDGE FROM THE ITCZ N TO 20N AND W OF 122W. THE LARGE NW SWELL TRAIN WITH COMBINED SEA HEIGHTS OF 8 TO 11 FT CONTINUES TO PROGRESS THROUGH THE AREA NW OF A LINE FROM NEAR 30N117W TO 12N128W TO 06N140W. THIS SWELL TRAIN WILL PROPAGATE S AND SE WHILE SHRINKING IN AREAL COVERAGE. BY 24 HOURS...IT IS FORECAST TO EXIST BETWEEN A LINE FROM 23N112W TO 12N125W TO 03N140W AND A LINE FROM 30N131W TO 23N140W...AND CONFINED TO THE NE PORTION OF THE AREA FROM ROUGHLY NEAR 30N128W TO 24N117W BY 48 HOURS WITH SEAS DOWN TO 8 FT. OTHER GAP WINDS... THE RECENT SUBSTANTIAL TIGHTENING OF THE PRES GRADIENT OVER FAR NW MEXICO AND THROUGH THE GULF OF CALIFORNIA HAS WEAKENED SOME OVER THE PAST FEW HOURS ALLOWING FOR NW 25-30 KT WINDS TO DIMINISH TO 20-25 KT FROM 23N-27N WITH SEAS TO 8 FT. MODEL GUIDANCE SUGGESTS THAT THESE WINDS DIMINISH TO AROUND 10-15 KT LATER THIS MORNING...AND SEAS LOWER TO 3-4 FT...AND TO 1-2 IN THE NORTHERN HALF OF THE GULF. LINGERING HIGHER SEAS IN THE RANGE OF 6-8 FT IN NW SWELL WILL BE CONFINED DOWNSTREAM OF THE GULF FROM ABOUT 17N-22N BETWEEN 106W-111W INTO WED. GULF OF PAPAGAYO...HIGH PRES WILL BUILD SE AND S ACROSS THE GULF OF MEXICO AND NW CARIBBEAN WITH THE PRES DIFFERENCE BETWEEN IT AND LOWER PRES OVER FAR NW COLOMBIA AND THE SW CARIBBEAN SEA FORECAST TO INDUCE AN INITIAL SURGE OF NE-E 20-25 KT WINDS THROUGH THE GULF BEGINNING LATE WED NIGHT. $$ AGUIRRE