000WTNT42 KNHC 140240TCDAT2TROPICAL DEPRESSION SEVEN DISCUSSION NUMBER 1NWS NATIONAL HURRICANE CENTER MIAMI FL AL0720111100 PM EDT SAT AUG 13 2011SATELLITE IMAGERY INDICATES THAT THE LOW PRESSURE AREASOUTH-SOUTHEAST OF BERMUDA HAS DEVELOPED PERSISTENT CENTRALCONVECTION AROUND A TIGHTLY-WOUND LOW-LEVEL CENTER. SATELLITEINTENSITY ESTIMATES FROM SAB AND TAFB ARE 30 KT...AND BASED ON THESEADVISORIES ARE INITIATED ON THE SYSTEM AS TROPICAL DEPRESSIONSEVEN.THE INITIAL MOTION IS 290/9. THE DEPRESSION IS CURRENTLY ON THESOUTHWEST SIDE OF A LARGE LOW-/MID-LEVEL RIDGE OVER THE CENTRALNORTH ATLANTIC. A DEEP-LAYER TROUGH ADVANCING INTO THE THE EASTERNUNITED STATES AND THE NORTHWESTERN ATLANTIC WILL BREAK DOWN THEWESTERN END OF THE RIDGE...CAUSING THE DEPRESSION TO TURN NORTHWARDBY 36 HR AND RECURVE NORTHEASTWARD INTO THE WESTERLIES BY 72 HR. THE FORECAST TRACK FOLLOWS THIS SCENARIO...WITH THE FORECAST BEINGA BLEND OF THE ECMWF AND GFDL MODEL FORECASTS. A POTENTIALCOMPLICATION TO THE TRACK FORECAST IS SHOWN BY THE UKMET MODEL...WHICH FORECASTS THE DEPRESSION TO EXPERIENCE ERRATIC MOTION DURINGTHE NEXT 48 HR AS IT INTERACTS WITH A DISTURBANCE CURRENTLY ABOUT400 N MI TO THE SOUTHEAST. IF SUCH INTERACTION OCCURS...IT WOULDDELAY THE APPROACH OF THE DEPRESSION TO BERMUDA.WATER VAPOR IMAGERY SHOWS SMALL UPPER-LEVEL LOWS TO THE SOUTHWESTAND NORTHEAST OF THE DEPRESSION. THESE SYSTEMS ARE HELPING TOPRODUCE LIGHT NORTHWESTERLY VERTICAL WIND SHEAR...AS WELL ASADVECTING UPPER-LEVEL DRY AIR INTO THE DEPRESSION. IN ADDITION...A LARGE PLUME OF AFRICAN DUST AND ASSOCIATED DRY AIR AREAPPROACHING THE DEPRESSION FROM THE EAST. WHILE VERTICAL SHEARSHOULD BE LIGHT ENOUGH FOR THE NEXT 48 HR TO ALLOW DEVELOPMENT...THE ABUNDANT DRY AIR AROUND THE SYSTEM SHOULD AT LEAST SLOWINTENSIFICATION. THE INTENSITY FORECAST CALLS FOR GRADUALSTRENGTHENING THROUGH 48 HR WHILE THE CYCLONE REMAINS OVER WARMWATER. AFTER 72 HR...THE CYCLONE IS EXPECTED TO BE ABSORBED INTO AFRONTAL SYSTEM OVER THE FAR NORTH ATLANTIC.THE FORECAST TRACK AND WIND RADII REQUIRE A TROPICAL STORM WATCH FORBERMUDA AT THIS TIME. A TROPICAL STORM WARNING WILL LIKELY BEREQUIRED SOMETIME ON SUNDAY.FORECAST POSITIONS AND MAX WINDSINIT 14/0300Z 27.9N 61.6W 30 KT 35 MPH 12H 14/1200Z 28.6N 62.6W 35 KT 40 MPH 24H 15/0000Z 30.1N 63.7W 40 KT 45 MPH 36H 15/1200Z 32.0N 64.0W 45 KT 50 MPH 48H 16/0000Z 35.0N 63.0W 50 KT 60 MPH 72H 17/0000Z 43.0N 55.0W 50 KT 60 MPH 96H 18/0000Z...ABSORBED BY FRONTAL SYSTEM$$FORECASTER BEVEN
000WTNT32 KNHC 141753TCPAT2BULLETINTROPICAL STORM GERT INTERMEDIATE ADVISORY NUMBER 3ANWS NATIONAL HURRICANE CENTER MIAMI FL AL072011200 PM AST SUN AUG 14 2011...DEPRESSION STRENGTHENS INTO THE SEVENTH TROPICAL STORM OF THESEASON SOUTH-SOUTHEAST OF BERMUDA...SUMMARY OF 200 PM AST...1800 UTC...INFORMATION----------------------------------------------LOCATION...28.6N 63.1WABOUT 275 MI...440 KM SSE OF BERMUDAMAXIMUM SUSTAINED WINDS...40 MPH...65 KM/HPRESENT MOVEMENT...NNW OR 335 DEGREES AT 7 MPH...11 KM/HMINIMUM CENTRAL PRESSURE...1009 MB...29.80 INCHES
000WTNT42 KNHC 142041TCDAT2TROPICAL STORM GERT DISCUSSION NUMBER 4NWS NATIONAL HURRICANE CENTER MIAMI FL AL072011500 PM AST SUN AUG 14 2011DEEP CONVECTION HAS CONTINUED TO DEVELOP OVER THE CENTER OF TROPICALSTORM GERT AND SMALL BANDING FEATURES HAVE BEEN TRYING TO DEVELOPIN THE NORTH AND EAST QUADRANTS OF THE CIRCULATION. AN AIR FORCERESERVE UNIT RECONNAISSANCE AIRCRAFT INVESTIGATING THE CYCLONE THISAFTERNOON FOUND MAXIMUM 850 MB FLIGHT-LEVEL WINDS OF 43 KT IN THESOUTHEAST QUADRANT ALONG WITH UNCONTAMINATED SFMR WINDS OF 39 AND41 KT. THE SFMR WINDS CORRELATE WELL WITH AN EARLIER 1324Z ASCATPASS THAT INDICATED SURFACE WINDS OF NEAR 40 KT IN THE SAME GENERALAREA OF THE CYCLONE CIRCULATION. BASED ON THE RECENT SFMR WINDS ANDEARLIER ASCAT WINDS...THE INITIAL INTENSITY IS INCREASED TO 40 KT.NOW THAT GERT HAS REDEVELOPED DEEP CONVECTION NEAR THE CENTER ANDHAS BECOME A MORE VERTICALLY DEEP SYSTEM...THE TROPICAL STORM HASSTARTED MOVING NORTH-NORTHWESTWARD...OR 335/07...TOWARD A WEAKNESSIN THE SUBTROPICAL RIDGE. WATER VAPOR IMAGERY INDICATES AFAST-MOVING SHORTWAVE TROUGH PASSING EASTWARD OVER AND NORTH OFBERMUDA WITH A SHORTWAVE RIDGE IN ITS WAKE...WHICH MAY ALLOW FORTHE SUBTROPICAL RIDGE TO BRIEFLY BUILD BACK WESTWARD AND CREATESOME STAIR-STEP MOTIONS TO THE NORTH-NORTHWEST AND NORTH.HOWEVER...ALL OF THE GLOBAL MODELS ARE IN EXCELLENT AGREEMENT ON ALARGE MID-LATITUDE TROUGH CURRENTLY OVER THE EASTERN U.S. MOVINGSTEADILY EASTWARD AND GRADUALLY ERODING THE WESTERN PERIPHERY OFTHE MID-LEVEL RIDGE ALONG 32N LATITUDE FOR THE NEXT 24-36 HOURS. ASA RESULT... THE STEERING FLOW SHOULD BECOME MORE SOUTHERLY ANDSTEER GERT NORTHWARD FOR THE NEXT 24 HOURS OR SO...AND THENACCELERATE THE CYCLONE NORTHEASTWARD THROUGH THE REMAINDER OF THEFORECAST PERIOD. THE OFFICIAL FORECAST TRACK IS SIMILAR TO THEPREVIOUS ADVISORY THROUGH 48 HOURS AND LIES CLOSE TO THE TIGHTLYPACKED GLOBAL MODEL SUITE.GERT HAS MOVED INTO A WEAK VERTICAL SHEAR REGION ON THE NORTH SIDEOF A SMALL UPPER-LEVEL LOW...WHICH HAS ALLOWED DEEP CONVECTION TOPERSIST AND PRODUCE A SMALL UPPER-LEVEL ANTICYCLONE OVER THE STORM.THIS FAVORABLE UPPER-LEVEL FLOW REGIME...ALONG WITH WARM SSTS ABOVE28C...IS EXPECTED TO PERSIST FOR THE NEXT 24 HOURS OT SO. THISSHOULD ALLOW FOR AT LEAST MODEST STRENGTHENING. AFTERTHAT...THERMODYNAMIC CONDITIONS ARE FORECAST BECOME LESSCONDUCIVE...WHICH SHOULD ALLOW FOR ONLY SLIGHT STRENGTHENING EVENTHOUGH THE VERTICAL SHEAR IS EXPECTED TO BE FAIRLY LOW. BY 48HOURS...GERT WILL BE MOVING OVER MUCH COOLER WATER ANDSOUTHWESTERLY VERTICAL SHEAR IS EXPECTED TO INCREASE ABOVE 30 KT.THIS COMBINATION OF UNFAVORABLE ENVIRONMENTAL CONDITIONS SHOULDCAUSE GERT TO MAKE THE TRANSITION INTO A POST-TROPICAL CYCLONE. THEINTENSITY FORECAST IS SIMILAR TO THE PREVIOUS ADVISORY AND CLOSELYFOLLOWS THE SHIPS AND LGEM INTENSITY MODELS.FORECAST POSITIONS AND MAX WINDSINIT 14/2100Z 28.9N 63.2W 40 KT 45 MPH 12H 15/0600Z 30.3N 63.8W 40 KT 45 MPH 24H 15/1800Z 32.3N 63.6W 45 KT 50 MPH 36H 16/0600Z 34.9N 61.8W 50 KT 60 MPH 48H 16/1800Z 38.9N 58.2W 50 KT 60 MPH 72H 17/1800Z 46.0N 45.0W 45 KT 50 MPH...POST-TROP/EXTRATROP 96H 18/1800Z...DISSIPATED$$FORECASTER STEWART
Guau! Menuda temporada de Tormentas Tropicales, crecen como setas.