000 AXPZ20 KNHC 020943 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC SAT JUN 02 2012 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. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM 10N86W TO 9N97W TO 11N105W TO 6N120W TO 6N127W. ITCZ EXTENDS FROM 06N127W TO BEYOND 05N140W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION EXISTS FROM 3N TO 9N W OF 92W...AND WITHIN 180 NM S OF THE BETWEEN 95W-99W. ...DISCUSSION... ALOFT...A RATHER SHARP MID/UPPER TROUGH EXTENDS FROM A LARGE UPPER LEVEL VORTEX LOCATED OVER N CENTRAL MEXICO NEAR 25N104W SSE TO 16N101W AND SSW TO 11N102W AND TO NEAR 4N104W. TO THE W OF TROUGH JUST ABOUT THE REMAINDER OF THE AREA IS UNDER THE INFLUENCE OF BROAD UPPER LEVEL RIDGING ANCHORED BY AN ANTICYCLONE AT 15N123W. THE NRN CREST OF THE RIDGE TILTS NE OVER THE FAR NE PORTION OF THE DISCUSSION AREA AND TOWARDS NRN BAJA CALIFORNIA AND SRN CALIFORNIA. WATER VAPOR IMAGERY SHOWS AMPLE MODERATE SUBSIDENCE ASSOCIATED WITH THE RIDGE COVERING THE AREA W OF THE TROUGH...EXCEPT IN THE FAR NW PORTION. THE MODERATE SUBSIDENCE IS RESULTING IN DRY AND VERY STABLE ATMOSPHERIC CONDITIONS W OF THE TROUGH. IN THE NW PORTION STRANDS OF UPPER LEVEL MOISTURE IN THE DIFFLUENT ZONE OF AN UPPER LEVEL LOW W OF THE AREA AT 21N147W...ARE IN THE FORM OF BROKEN CIRRUS CLOUDS. THESE CLOUDS ARE WITHIN 150 NM OF LINE FROM 14N138W TO 22N134W TO 28N125W...AND ARE RIDING NEWD ALONG THE NW PERIPHERY OF THE RIDGE. IN THE FAR EASTERN PART OF THE AREA E OF THE MID/UPPER LEVEL TROUGH...BROAD SCALE RIDGING IS PRESENT TO THE N OF 07N WITH A SMALL ANTICYCLONE AT 10N90W. A VERY RICH MOISTURE LADEN ATMOSPHERE E OF THE TROUGH IS FUELING SCATTERED SHOWERS AND TSTMS N OF 03N E OF 100W. THIS ACTIVITY IS FURTHER AIDED BY UPPER LEVEL DIVERGENCE E OF THE TROUGH. THE PRESENCE OF THIS WEATHER IS EXPECTED TO CONTINUE INTO THE NEXT 48 HRS AS THE TROUGH REMAINS ABOUT STATIONARY BETWEEN BOTH RIDGE FEATURES. THE SRN PORTION OF A NARROW UPPER TROUGH IS QUICKLY MOVING EWD ALONG 32N AT 128W FOLLOWED BY BROAD W TO NW FLOW. THIS TROUGH WILL MOVE INLAND THE U.S. W COAST BY EARLY TONIGHT. ANOTHER TROUGH IS NOTED WELL TO THE NW OF THE DISCUSSION AREA. THIS TROUGH IS FORECAST TO SHARPEN AS IT JUST MOVES INTO THE FAR NW PART ON SUN. THE BROAD UPPER RIDGE WILL RESPOND BY BROADENING OUT...BUT WITH THE TROUGH SHARPENING A NEW RIDGE FORMS IN THE CENTRAL U.S. AND AMPLIFIES THROUGH EARLY NEXT WEEK FORCING THE VORTEX OVER MEXICO TO LIFT N TO THE SW U.S. AND WEAKEN. AT THE SURFACE...A 1025 MB HIGH IS CENTERED NW OF THE DISCUSSION AREA AT 36N146W WITH A RIDGE STRETCHING FROM IT SEWD TO 25N128W TO NEAR 21N120W. THE PRES DIFFERENCE BETWEEN THE RIDGE AND LOWER PRES IN THE TROPICS IS RESULTING IN MODERATE TO FRESH NE TRADE WINDS FROM ABOUT 8N TO 14N W OF 130W. A COLD FRONT ASSOCIATED WITH THE UPPER LEVEL TROUGH IS FORECAST TO CLIP THE FAR NW CORNER ON SUN CAUSING THE RIDGE TO WEAKEN...AND THUS BREAKING DOWN THE GRADIENT RESPONSIBLE FOR THE MODERATE TO NE TRADES. THESE TRADE WINDS WILL BE FORECAST TO DIMINISH TO LESS THAN 20 KT IN 24 HRS. THE COLD FRONT WILL MOVE TO THE FAR N CENTRAL WATERS BY EARLY MON...BUT QUICKLY DISSIPATE AS IT BECOMES OVERWRITTEN BY STRENGTHENING HIGH PRES FROM THE NW. A TIGHTENING PRES GRADIENT OVER THE FAR NW WATERS AT THAT TIME SHOULD ALLOW FOR N TO NE 20 KT WINDS THERE. THE TRADES THAT ARE FORECAST TO DIMINISH OVER THE FAR WRN PART OF THE AREA IN 24 HRS...MAY ATTEMPT TO COME BACK MON MORNING ALSO DUE TO THE STRENGTHENING HIGH PRES. A PARTIAL ASCAT PASS FROM JUST PAST 0500 UTC THIS MORNING REVEALED NLY 20 KT WINDS OVER MUCH OF THE NE AND N CENTRAL PORTIONS OF THE AREA. THE CULPRIT TIGHT PRES GRADIENT AS A RESULT OF THE PRES DIFFERENCE BETWEEN THE ABOVE MENTIONED RIDGE AND VERY LOW PRES OVER NW MEXICO AND THE SW U.S. IS INDUCING THESE WINDS. SEAS THERE ARE UP TO 9 FT PRIMARILY N OF 28N. WITH THE RIDGE WEAKENING THROUGH SUN...THE GRADIENT SLACKENS ALLOWING FOR THESE WINDS TO DIMINISH TO LESS THAN 20 KT. MIXED NW AND S SWELLS THERE WILL ALLOW FOR SEAS OF 8 FT. THE WEAK 1011 MB LOW ON THE MONSOON TROUGH AT 7N117W REFERENCED UNDER THE ALOFT SECTION...IS MOVING W ABOUT 7 KT. A 30 NM WIDE CLUSTER OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS NOTED JUST E OF THE LOW. RESULTANT UPPER LEVEL DEBRIS MOISTURE IS SEEN AS SCATTERED TO BROKEN CIRRUS CLOUDS FANNING AWAY FROM THE LOW WITHIN 300 NM TO ITS N AND 180 NM TO ITS S. THE ASCAT PASS FROM 0458 UTC LAST NIGHT SHOWED THE CYCLONIC CIRCULATION TO BE ELONGATED NE TO SW ALONG THE MONSOON TROUGH. THE LOW IS UNDER THE SE PERIPHERY OF THE ANTICYCLONE AT 15N123W WHERE EASTERLY VERTICAL SHEAR REMAINS MODERATE...AND THUS NO ORGANIZATION WILL BE FORECAST AS TROPICAL CYCLONE DEVELOPMENT IS RARELY ACHIEVED AT SUCH A LOW LATITUDE. THE GLOBAL MODELS TRACK THE LOW IN A GENERAL W TO NW DIRECTION OVER THE NEXT COUPLE OF DAYS...BUT WITH NO SIGNIFICANT ORGANIZATION EXPECTED. LONG-PERIOD CROSS-EQUATORIAL S SWELLS PRODUCING COMBINED SEAS OF 8 FT ARE PRESENT S OF 7N BETWEEN 100W AND 125W. MOST OF THE WAVEWATCH MODEL GUIDANCES DEPICT THESE SWELLS TO PROPAGATE N TO NEAR 10N BETWEEN 100W-125W IN ABOUT 24 HRS...THEN BEGIN TO DECAY WITHIN 36-48 HRS ALLOWING FOR SEAS TO SUBSIDE TO LESS THAN 8 FT. RESIDUAL SWELL ENERGY MAY BE ENOUGH TO BRING SEAS OF 6-7 FT TOWARDS THE COAST OF MEXICO SUN AND MON AS ALSO INDICATED BY CONSENSUS OF THE WAVEWATCH GUIDANCES. $$ AGUIRRE