000WTNT44 KNHC 210233TCDAT4TROPICAL DEPRESSION FOURTEEN DISCUSSION NUMBER 1NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL1420101100 PM EDT MON SEP 20 2010SATELLITE IMAGES INDICATE THAT THE AREA OF LOW PRESSURE LOCATEDABOUT 450 N MI WEST OF THE CAPE VERDE ISLANDS HAS DEVELOPEDENOUGH ORGANIZED CONVECTION TO BE CLASSIFIED A TROPICALDEPRESSION...THE FOURTEENTH OF THE 2010 ATLANTIC HURRICANE SEASON.SATELLITE INTENSITY ESTIMATES FROM TAFB AND SAB ARE 35 KT AND 30KT...RESPECTIVELY. BASED ON THESE ESTIMATES...THE INITIAL INTENSITYIS SET AT 30 KT. DEEP CONVECTION HAS BEEN INCREASING IN INTENSITYAND COVERAGE DURING THE PAST COUPLE OF HOURS AND THE DEPRESSIONIS NEARING TROPICAL STORM STRENGTH.THE INITIAL MOTION ESTIMATE IS 360/5...BASED MAINLY ON SATELLITEFIXES. THE DEPRESSION IS CAUGHT IN WEAK STEERING CURRENTS TO THESOUTH OF A LARGE DEEP-LAYER TROUGH OVER THE EASTERN ATLANTIC OCEAN.A GENERAL SLOW NORTHWARD MOTION IS EXPECTED FOR THE NEXT 24 TO 36HOURS AS THE SYSTEM REMAINS IN THE WEAK FLOW. A TURN TO THENORTHWEST IS PROBABLE IN A COUPLE OF DAYS AS THE TROUGH SHIFTS EASTAND FLATTENS...ALLOWING FOR SOME MID-LEVEL RIDGING TO BUILD NORTHOF THE CYCLONE. ANOTHER TROUGH...HOWEVER...IS EXPECTED TO PASSNORTH OF THE SYSTEM BY THE END OF THE FORECAST PERIOD AND WILLLIKELY INDUCE A SLOW NORTHWARD MOTION BY THAT TIME. THERE IS ALARGE SPREAD IN THE MODEL GUIDANCE AND THE OFFICIAL TRACK FORECASTIS OF LOWER CONFIDENCE THAN NORMAL.MOST OF THE INTENSITY MODELS SHOW SOME STRENGTHENING DURING THE NEXTFEW DAYS AS THE CYCLONE IS EXPECTED TO REMAIN OVER MARGINALLY WARMSEA SURFACE TEMPERATURES AND IN A LOW WIND SHEAR ENVIRONMENT...BUTJUST SOUTH OF STRONG WESTERLY UPPER-LEVEL WINDS. WESTERLY SHEAROVER THE SYSTEM COULD INCREASE IN 4 OR 5 DAYS...ASSOCIATED WITH THEAFOREMENTIONED SECOND TROUGH. THE OFFICIAL FORECAST IS IN BESTAGREEMENT WITH THE INTENSITY MODEL CONSENSUS AND SHOWS GRADUALSTRENGTHENING FOR THE NEXT FEW DAYS FOLLOWED BY LITTLE CHANGE INSTRENGTH THEREAFTER.FORECAST POSITIONS AND MAX WINDSINITIAL 21/0300Z 17.1N 31.9W 30 KT 12HR VT 21/1200Z 17.5N 31.7W 35 KT 24HR VT 22/0000Z 18.0N 31.6W 40 KT 36HR VT 22/1200Z 18.4N 31.8W 40 KT 48HR VT 23/0000Z 18.9N 32.4W 45 KT 72HR VT 24/0000Z 20.1N 34.4W 50 KT 96HR VT 25/0000Z 22.0N 35.5W 55 KT120HR VT 26/0000Z 23.5N 35.5W 55 KT$$FORECASTER CANGIALOSI
000WTNT44 KNHC 211445TCDAT4TROPICAL STORM LISA DISCUSSION NUMBER 3NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL1420101100 AM EDT TUE SEP 21 2010INTERMITTENT BURSTS OF DEEP CONVECTION HAVE BEEN OCCURRING NEAR THEWELL-DEFINED CIRCULATION CENTER NOTED IN A 21/0932Z SSMIS OVERPASS. UPPER-LEVEL OUTFLOW HAS ALSO GRADUALLY BEEN IMPROVING TO THE NORTHAND SOUTH OF LISA. THE INITIAL INTENSITY HAS BEEN INCREASED TO 40KT BASED ON A BLEND OF DVORAK SATELLITE INTENSITY ESTIMATES OFT2.5/35 KT FROM BOTH TAFB AND SAB...AND UW-CIMSS ADT CURRENTINTENSITY ESTIMATES OF T3.5/45 KT.AFTER A BRIEF JOG TO THE NORTHEAST A FEW HOURS AGO...LISA HASRESUMED A MOTION ESTIMATE OF 360/4. LISA IS EXPECTED TO MOVE SLOWLYNORTHWARD FOR THE NEXT 24 HOURS OR SO DUE TO THE COMBINATION OFWEAK STEERING CURRENTS ASSOCIATED WITH A BREAK IN THE SUBTROPICALRIDGE AND MODERATE NORTHWESTERLY FLOW ON THE WEST SIDE OF ADEEP-LAYER TROUGH SITUATED TO THE NORTH OF THE CYCLONE. AS THEAFOREMENTIONED TROUGH LIFTS OUT TO THE NORTHEAST BY 36-48 HOURS...THE RIDGE TO THE NORTH OF LISA IS EXPECTED TO BUILD BACK IN ANDFORCE THE CYCLONE ON A SLOW WEST-NORTHWESTWARD TRACK. THE MODELGUIDANCE IS WIDELY DIVERGENT WITH THE HWRF/GFDL MODELS TAKING LISADUE NORTH THROUGHOUT THE FORECAST PERIOD...WHILE THE NOGAPS/GFDNMODELS MOVE LISA DUE WEST. THE REST OF THE NHC MODEL GUIDANCE ISSPREAD OUT EVENLY BETWEEN THESE TWO EXTREMES. SUCH A LARGE SPREADIN THE MODEL GUIDANCE TYPICALLY SUGGESTS THAT THE FORWARD MOTIONWILL BE RELATIVELY SLOW...AND THAT IS REFLECTED IN THIS FORECASTPACKAGE. THE OFFICIAL FORECAST TRACK IS SIMILAR THE PREVIOUSADVISORY TRACK AND LIES A LITTLE NORTH OF THE MODEL CONSENSUS.ALTHOUGH THE VERTICAL SHEAR IS EXPECTED TO REMAIN LOW FOR ABOUT THENEXT 72 HOURS...THE MID-LEVEL MOISTURE ENVIRONMENT SURROUNDING LISAIS FORECAST TO DRY OUT CONSIDERABLY AND SSTS ARE EXPECTED TO DROPBELOW 27C. THE DRIER AIR AND COOLER WATER MAY PUT THE BREAKS ON THEINTENSIFICATION PROCESS AS THE CYCLONE NEARS HURRICANE STRENGTH IN48-72 HOURS. AFTER 72 HOURS...LISA IS EXPECTED TO BEGIN FEELING THEEFFECTS OF INCREASING WESTERLY SHEAR AS ANOTHER UPPER-LEVEL TROUGHDIGS SOUTHWARD AND AMPLIFIES TO THE NORTHWEST OF THE CYCLONE. ITSHOULD BE NOTED THAT THE ECMWF MODEL DOES NOT MOVE LISA NORTH OF20N LATITUDE...WHICH KEEPS THE CYCLONE IN A LOWER SHEAR ENVIRONMENTBENEATH AN UPPER-LEVEL ANTICYCLONE FROM 72-120 HOURS. THE OFFICIALINTENSITY FORECAST IS A BLEND OF THE SHIPS AND LGEM INTENSITYMODELS...AND LEANS A LITTLE TOWARD THE STRONGER ECMWF SOLUTION.FORECAST POSITIONS AND MAX WINDSINITIAL 21/1500Z 18.1N 31.7W 40 KT 12HR VT 22/0000Z 18.3N 31.7W 45 KT 24HR VT 22/1200Z 18.7N 31.8W 50 KT 36HR VT 23/0000Z 19.0N 32.2W 55 KT 48HR VT 23/1200Z 19.4N 33.0W 60 KT 72HR VT 24/1200Z 20.1N 34.5W 55 KT 96HR VT 25/1200Z 20.9N 35.8W 50 KT120HR VT 26/1200Z 21.0N 37.5W 45 KT$$FORECASTER STEWART
000WTNT44 KNHC 212034TCDAT4TROPICAL STORM LISA DISCUSSION NUMBER 4NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL142010500 PM EDT TUE SEP 21 2010AFTER A SHORT-LIVED DECREASE IN THE CENTRAL CONVECTION...A BURSTOF STRONG CONVECTION HAS RECENTLY DEVELOPED OVER THE WELL-DEFINEDLOW-LEVEL CIRCULATION CENTER. RECENT TRMM AND AMSU MICROWAVEOVERPASSES INDICATE THE LOW- AND MID-LEVEL CIRCULATIONS HAVETIGHTENED UP AND BECOME MORE VERTICALLY ALIGNED...SUGGESTING THATTHE VERTICAL SHEAR AFFECTING THE SYSTEM HAS DECREASED. UPPER-LEVELOUTFLOW CONTINUES TO IMPROVE IN ALL QUADRANTS. THE INITIALINTENSITY REMAINS AT 40 KT BASED ON A BLEND OF DVORAK SATELLITEINTENSITY ESTIMATES OF T2.5/35 KT FROM BOTH TAFB AND SAB...ANDUW-CIMSS ADT CURRENT INTENSITY ESTIMATE OF T3.4/53 KT.THE INITIAL MOTION ESTIMATE IS 360/2. LISA HAS BEEN WOBBLING BETWEENA NORTH AND NORTHEAST DIRECTION...PROBABLY DUE TO RE-ORGANIZATIONOF THE SYSTEM CENTER. NOW THAT THE VERTICAL CIRCULATIONS APPEAR TOBE MORE VERTICALLY ALIGNED...HOPEFULLY THIS WILL RESULT IN LESSSCATTER IN THE SATELLITE FIX POSITIONS. LISA IS EXPECTED REMAIN INVERY WEAK STEERING FLOW FOR THE NEXT 48-72 HOURS. AFTERWARDS...AMID-LEVEL TROUGH SITUATED JUST NORTH OF THE CYCLONE IS FORECAST TOSLOWLY LIFT OUT TO THE NORTHEAST...ALLOWING THE SUBTROPICAL RIDGETO BUILD WESTWARD TO THE NORTH OF LISA...WHICH SHOULD NUDGE THECYCLONE ON A SLOW WESTWARD OR WEST-NORTHWESTWARD TRACK. THE NHCMODEL GUIDANCE REMAINS WIDELY DIVERGENT BETWEEN THE NORTHWARD HWRFAND THE WESTWARD GFDN MODEL SOLUTIONS. THE OFFICIAL FORECAST TRACKIS SIMILAR THE PREVIOUS ADVISORY...AND REMAINS NORTH OF THE MODELCONSENSUS AND BETWEEN THE GFS AND ECMWF TRACKS.THE VERTICAL SHEAR IS FORECAST TO REMAIN BELOW 10 KT FOR THE NEXT 48 HOURS...WHICH USUALLY FAVORS SIGNIFICANT INTENSIFICATION.HOWEVER...MID-LEVEL MOISTURE IS FORECAST TO DECREASE WITH HUMIDITYLEVELS BELOW 40 PERCENT AFTER 24 HOURS. DESPITE THE PRESENCE OF DRYAIR...¿JULIA? IS FORECAST TO STRENGTHEN FAIRLY QUICKLY IN THE NEXT 24HOURS DUE TO THE IMPROVED INNER-CORE STRUCTURE NOTED IN THEAFOREMENTIONED MICROWAVE IMAGERY. GIVEN THAT A 75-PERCENT EYEWALLFEATURE EXISTED 6 HRS AGO AND CLOUD TOPS HAVE RECENTLY COOLED TOBELOW -80C NEAR THE CENTER...A PERIOD OF RAPID INTENSIFICATION CANNOT BE RULED OUT. THE ECMWF MODEL CONTINUES TO KEEP LISA SOUTH OF20N LATITUDE AND BENEATH AN UPPER-LEVEL ANTICYCLONE. THE OFFICIALINTENSITY FORECAST IS ABOVE THE OBJECTIVE INTENSITY GUIDANCE THROUGH48 HOURS AND CONTINUES TO LEAN TOWARD THE STRONGER ECMWF SOLUTION.FORECAST POSITIONS AND MAX WINDSINITIAL 21/2100Z 18.3N 31.6W 40 KT 12HR VT 22/0600Z 18.6N 31.7W 50 KT 24HR VT 22/1800Z 19.0N 31.9W 60 KT 36HR VT 23/0600Z 19.3N 32.5W 65 KT 48HR VT 23/1800Z 19.7N 33.3W 65 KT 72HR VT 24/1800Z 20.4N 34.7W 55 KT 96HR VT 25/1800Z 21.0N 36.0W 45 KT120HR VT 26/1800Z 21.0N 38.0W 40 KT$$FORECASTER STEWART
Pedazo de PRE, qué bien visto Pedro.
000WTNT44 KNHC 220841TCDAT4TROPICAL STORM LISA DISCUSSION NUMBER 6NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL142010500 AM EDT WED SEP 22 2010INFRARED SATELLITE IMAGES INDICATE THAT THERE HAS BEEN LITTLESIGNIFICANT CHANGE ASSOCIATED WITH THE CLOUD PATTERN OF LISA. THECYCLONE CONSISTS OF A CENTRAL MASS OF PULSATING DEEP CONVECTION...ALTHOUGH WITH FEWER BANDING FEATURES THAN YESTERDAY. SEVERAL RECENTMICROWAVE OVERPASSES SUGGEST THAT THE LOW- AND MID-LEVEL CENTERSARE NOT CO-LOCATED...A SIGN THAT THE CYCLONE IS BEING IMPACTED BYVERTICAL WIND SHEAR. DVORAK CI NUMBERS AT 0600 UTC ARE AT 2.5 AND3.0 FROM SAB AND TAFB...RESPECTIVELY. A BLEND OF THESE ESTIMATESIS THE BASIS FOR KEEPING THE INITIAL INTENSITY AT 40 KT FOR THISADVISORY. THE CENTER HAS BEEN DIFFICULT TO LOCATE BUT RECENT MICROWAVE ANDSATELLITE FIXES SUGGEST THAT IT BE A LITTLE FARTHER SOUTH THANPREVIOUSLY INDICATED. A SHORT-TERM INITIAL MOTION FROM THESE FIXESYIELDS AN ESTIMATE OF 060/4. THE TRACK GUIDANCE CONTINUES TO BEFAIRLY DIVERGENT BUT GENERALLY SHOWS LISA DRIFTING SOUTH OR EAST INA REGION OF WEAK STEERING DURING THE 48 HOURS. AFTER THAT...A TURNTOWARD WEST-NORTHWEST IS EXPECTED WITH A FASTER FORWARD SPEED AS AWEAK LOW- TO MID-LEVEL RIDGE BUILDS NORTH OF THE STORM. GIVEN THELARGE SPREAD IN THE GLOBAL MODELS...THE NEW NHC TRACK FORECASTREMAINS OF LOW CONFIDENCE AND IS SLOWED FURTHER UNTIL A MOREESTABLISHED TREND IS EVIDENT IN THE GUIDANCE.WATER VAPOR IMAGERY SHOWS A SHARP UPPER-LEVEL TROUGH NORTH OF LISATHAT IS FORECAST TO LIFT OUT IN 24-48 HOURS. THIS FEATURE HAS BEENIMPARTING A NORTHWESTERLY SHEAR OVER THE STORM...BUT SHIPS MODELOUTPUT INDICATES THAT THIS SHEAR SHOULD NOT BE PARTICULARLY STRONGDURING THIS TIME. AFTER ABOUT 60-72 HOURS...HOWEVER...GLOBALMODELS FORECAST A STRENGTHENING OF UPPER-LEVEL WESTERLY FLOW OVERLISA...AND THE INTENSITY GUIDANCE SHOWS WEAKENING LATER IN THEPERIOD. OF COURSE...THE INTENSITY GUIDANCE IS HIGHLY DEPENDENT ONWHERE LISA IS LOCATED AT THAT TIME...AND THE GREATER THAN NORMALUNCERTAINTY REGARDING ITS FORECAST TRACK MAKES THE CURRENTINTENSITY FORECAST DIFFICULT. THE NEW NHC INTENSITY FORECAST HASBEEN ADJUSTED A BIT DOWNWARD BEFORE 72 HOURS BUT REMAINS AT ORABOVE THE STATISTICAL-DYNAMICAL OUTPUT.FORECAST POSITIONS AND MAX WINDSINITIAL 22/0900Z 18.0N 30.5W 40 KT 12HR VT 22/1800Z 18.0N 30.5W 45 KT 24HR VT 23/0600Z 17.9N 30.5W 50 KT 36HR VT 23/1800Z 17.8N 30.5W 50 KT 48HR VT 24/0600Z 17.8N 30.7W 55 KT 72HR VT 25/0600Z 18.5N 32.5W 50 KT 96HR VT 26/0600Z 19.5N 35.0W 45 KT120HR VT 27/0600Z 21.0N 38.0W 35 KT$$FORECASTER KIMBERLAIN