000 AXNT20 KNHC 071102 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT MON JUL 07 2014 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS OF SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST FROM THE EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL ANALYSIS. BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1115 UTC. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 02N25W TO 11N28W MOVING W AT 15-20 KT. DESPITE THE LOW LATITUDE NATURE OF THE WAVE...WITH THE MID- LEVEL VORTEX BEING NEAR 08N...THE SYSTEM HAS MAINTAINED AN IMPRESSIVE SATELLITE PRESENTATION WITH DEEP CONVECTION INTACT SINCE LEAVING WEST AFRICA ABOUT A DAY PREVIOUS. AN EARLIER ASCAT SCATTEROMETER PASS INDICATED A HIGH AMPLITUDE TROUGH...BUT WITHOUT A CLOSED CIRCULATION. SCATTERED MODERATE CONVECTION EXISTS IN ASSOCIATION WITH THE WAVE WITHIN 60 NM OF THE AXIS BETWEEN 05N AND 09N. TROPICAL WAVE EXTENDS FROM 05N45W TO 13N39W MOVING W AT 15-20 KT. A STRONG SAHARAN AIR LAYER SIGNAL IS NOTED ON METEOSAT-9 AND TOTAL PRECIPITABLE WATER IMAGERY SURROUNDING THE WAVE THAT CONTINUES TO RESULT IN AN OVERALL LACK OF ANY SIGNIFICANT CONVECTION AT THIS TIME. DURING THE PAST 24 HOURS...THE WAVE HAS LIKELY DISPERSED A PORTION OF ITS ENERGY INTO A MID-LATITUDE AMPLIFIED 700 MB TROUGH WHICH LIES TO THE WEST N OF 12N BETWEEN 40-45W. NO SIGNIFICANT DEEP CONVECTION IS NOTED WITH THE WAVE AT THIS TIME. TROPICAL WAVE EXTENDS FROM 10N81W TO 22N75W MOVING W AT ABOUT 20 KT. THE WAVE CONTINUES TO TRACK ACROSS THE WESTERN CARIBBEAN THIS EVENING AS A BROAD 700 MB TROUGH WITH ENHANCED TOTAL PRECIPITABLE WATER EAST OF THE TROUGH AXIS. ISOLATED MODERATE CONVECTION IS WITHIN 120 NM OF THE AXIS N OF 19N. TROPICAL WAVE EXTENDS FROM 11N96W IN THE NORTHEASTERN PACIFIC OCEAN TO 22N93W MOVING WNW AT 15-20 KT. THE WAVE IS INDISTINCT AT THE SURFACE AND IN THE TOTAL PRECIPITABLE WATER IMAGERY...HOWEVER... IT IS STILL PRESENT IN THE SUNY-ALBANY TROPICAL TROUGH DIAGNOSTICS AT 700 MB. GIVEN ITS MOTION TO THE WNW AND MOVING OUT OF THE DEEP TROPICS...ANOTHER OPTION IS TO CONSIDER THE SYSTEM A TROUGH RATHER THAN A TROPICAL WAVE. THE WAVE IS CURRENTLY MOVING BENEATH AN UPPER LEVEL SOUTHWESTERLY FLOW PATTERN THAT REMAINS FAIRLY DIFFLUENT ON THE EASTERN PERIPHERY OF UPPER-LEVEL LOW CENTERED OVER EAST-CENTRAL MEXICO NEAR 22N101W. WHILE SUBSTANTIAL DEEP CONVECTION OCCURRED OVER SOUTHERN MEXICO LATE YESTERDAY...NO SIGNIFICANT DEEP CONVECTION IS CURRENTLY OCCURRING. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 16N17W TO 07N25W. A BREAK OCCURS IN THE TROUGH IN ASSOCIATION WITH A TROPICAL WAVE. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 06N30W TO 04N52W ON THE SOUTH AMERICAN COAST. ASIDE FROM THE CONVECTION NEAR 27W ASSOCIATED WITH THE WAVE...SCATTERED MODERATE CONVECTION IS WITHIN 60 NM OF THE ITCZ EAST OF 34W. THE NORTHEAST PACIFIC MONSOON TROUGH EXTENDS ACROSS CENTRAL AMERICA AND ENTERS THE CARIBBEAN SEA AT 09N82W AND EXTENDS TO COLOMBIA AT 10N76W. SCATTERED MODERATE CONVECTION EXISTS WITHIN 60 NM OF THE TROUGH AXIS. ...DISCUSSION... GULF OF MEXICO... A WEAK 1019 MB HIGH IS LOCATED OVER THE SW GULF OF MEXICO THIS MORNING AT 21N97W WITH WEAK RIDGING RESIDING ACROSS THE GULF. THE RESULTING VERY WEAK PRESSURE GRADIENT IS PRODUCING LIGHT TO GENTLE BREEZE WINDS OVER THE GULF. AN UPPER-LEVEL LOW CENTERED OVER EAST-CENTRAL MEXICO NEAR 22N101W INTERACTING WITH THE AFOREMENTIONED WESTERNMOST TROPICAL WAVE IS HELPING TO PROMOTE SCATTERED UPPER-LEVEL CLOUDINESS OVER THE SOUTHERN GULF BUT WITH LITTLE DEEP CONVECTION. AN UPPER TROUGH OVER THE SOUTHEAST US IS HELPING TO MAINTAIN A SURFACE TROUGH ALONG THE WEST COAST OF THE FLORIDA PENINSULA WITH SCATTERED SHOWERS WITHIN 60 NM OF THE TROUGH. MOST OF THE GULF IS COVERED BY SUBSTANTIAL LOW- LEVEL MOISTURE AS DEPICTED BY THE TOTAL PRECIPITABLE WATER IMAGERY. ISOLATED CONVECTION OVER THE GULF MAY OCCUR IN THE NEXT COUPLE OF DAYS...WITH SUBSTANTIAL DEEP CONVECTION OVER SURROUNDING LAND AREAS DURING THE AFTERNOON DIURNAL MAXIMUM. CARIBBEAN SEA... A MODERATE NORTH-SOUTH PRESSURE GRADIENT IS PRODUCING MODERATE TO FRESH TRADEWINDS ACROSS MOST OF THE CARIBBEAN WITH STRONG BREEZE CONDITIONS JUST NORTH OF COLOMBIA AS SEEN IN AN EARLIER ASCAT SCATTEROMETER PASS. NO SIGNIFICANT DEEP CONVECTION IS CURRENTLY OCCURRING ACROSS THE CARIBBEAN. SUBSTANTIAL LOW-LEVEL MOISTURE IS PRESENT ACROSS THE CENTRAL CARIBBEAN DUE TO THE TROPICAL WAVE JUST EAST OF 80W. AS THIS WAVE PROGRESSES WESTWARD DURING THE NEXT COUPLE OF DAYS...CHANCES FOR DEEP CONVECTION INCREASES SOME OVER THE WESTERN CARIBBEAN AND DIMINISHES OVER THE EASTERN CARIBBEAN. A FAIRLY LARGE SAHARAN AIR LAYER WILL OVERSPREAD MOST OF THE CARIBBEAN AND SHOULD SUPPRESS DEEP CONVECTION FOR A FEW DAYS. ...HISPANIOLA... NO SIGNIFICANT DEEP CONVECTION IS CURRENTLY OCCURRING ACROSS HISPANIOLA. SUBSTANTIAL LOW-LEVEL MOISTURE IS PRESENT ACROSS THE CENTRAL CARIBBEAN DUE TO THE TROPICAL WAVE JUST EAST OF 80W. AS THIS WAVE PROGRESSES WESTWARD DURING THE NEXT COUPLE OF DAYS...CHANCES FOR DEEP CONVECTION FOR HISPANIOLA ARE HIGHER THAN TYPICAL ON MONDAY...BUT THEN DIMINISH ON TUESDAY AND FOR THE NEXT COUPLE OF DAYS. A FAIRLY LARGE SAHARAN AIR LAYER WILL OVERSPREAD MOST OF THE CARIBBEAN WITHIN A FEW DAYS AND SUPPRESS THE USUAL LATE AFTERNOON DEEP CONVECTION OVER LAND. ATLANTIC OCEAN... A LARGE BERMUDA-AZORES HIGH EXTENDS ACROSS THE ATLANTIC FROM 38N15W WEST-SOUTHWESTWARD TO 29N75W. THE EQUATORWARD PRESSURE GRADIENT IS WEAKER THAN USUAL AND IS PRODUCING E TO NE GENTLE TO FRESH BREEZE TRADEWINDS ACROSS MOST OF THE TROPICAL ATLANTIC. A WEAK MIDDLE TO UPPER-LEVEL SHORTWAVE TROUGH IS NOTED ON WATER VAPOR IMAGERY JUST OFFSHORE OF NE FLORIDA. SCATTERED MODERATE CONVECTION IS OCCURRING N OF 27N W OF 78W. AN UPPER LEVEL LOW OVER THE BAHAMAS NEAR 25N73W HAS WIDELY SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS FROM 22-27N AND BETWEEN 68W AND 75W. A COUPLE OF WEAK SURFACE TROUGHS ARE PRESENT ALONG 39W AND 50W NORTH OF 22N...THOUGH NEITHER HAVE ANY DEEP CONVECTION CURRENTLY. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ LANDSEA