742
WTNT41 KNHC 200237
TCDAT1
TROPICAL DEPRESSION SIX DISCUSSION NUMBER 3
NWS NATIONAL HURRICANE CENTER MIAMI FL AL062026
300 AM GMT SUN SEP 20 2026
THE CONVECTIVE ORGANIZATION OF THE DEPRESSION HAS INCREASED
SOMEWHAT SINCE THE LAST ADVISORY, WITH MULTIPLE CONVECTIVE BANDS IN
THE NORTHERN SEMICIRCLE. THIS INCREASE IS REFLECTED IN THE VARIOUS
SUBJECTIVE AND OBJECTIVE SATELLITE INTENSITY ESTIMATES NOW
SUGGESTING THE CYCLONE HAS REACHED TROPICAL STORM STRENGTH.
HOWEVER, AN ASCAT-C OVERPASS SHOWED MAXIMUM WINDS NEAR 30 KT. BASED
MAINLY ON THAT THE INITIAL INTENSITY WILL REMAIN 30 KT. CIRRUS
CLOUD MOTION INDICATE THAT AN UPPER-LEVEL CYCLONIC SHEAR AXIS IS
LOCATED NEAR OR JUST SOUTH OF THE CENTER, WITH VERY STRONG
UPPER-LEVEL WESTERLY FLOW OVER THE SOUTHERN PART OF THE LOW-LEVEL
CIRCULATION.
THE INITIAL MOTION IS 020/4 KT. THE DEPRESSION IS IN AN AREA OF
WEAK STEERING CURRENTS BETWEEN A LOW- TO MID-LEVEL RIDGE TO THE
EAST AND A DEEP-LAYER MID-LATITUDE TROUGH TO THE NORTHWEST. DURING
THE NEXT COUPLE OF DAYS, THE SOUTHERN PORTION OF THIS TROUGH IS
EXPECTED TO WEAKEN, WITH A LOW- TO MID-LEVEL RIDGE DEVELOPING TO
THE WEST AND NORTHWEST OF THE TROPICAL CYCLONE. THIS SHOULD RESULT
IN THE CYCLONE STOPPING ITS NORTH-NORTHEASTWARD MOTION AND TURNING
TOWARD THE SOUTHWEST. A GENERAL SOUTHWESTWARD MOTION IS THEN LIKELY
UNTIL THE SYSTEM DISSIPATES. THE TRACK GUIDANCE HAS SHIFTED A BIT
WESTWARD AFTER 36 H, AND THE NEW FORECAST TRACK IS ALSO NUDGED A
BIT WEST OF THE PREVIOUS TRACK.
THE DYNAMICAL MODELS ARE FORECASTING A SMALL UPPER-LEVEL LOW TO
DEVELOP ALONG THE CYCLONIC SHEAR AXIS NEAR OR SOUTH OF THE TROPICAL
DEPRESSION DURING THE NEXT 12 H OR SO. THIS IS LIKELY CREATE A LESS
HOSTILE SHEAR ENVIRONMENT AROUND THE DEPRESSION THAT SHOULD ALLOW
SOME INTENSIFICATION. AFTER 24 H, THE MODELS ARE IN GOOD AGREEMENT
THAT STRONG UPPER-LEVEL NORTHERLY OR NORTHWESTERLY WINDS WILL MOVE
OVER THE CYCLONE, CREATING STRONG SHEAR AND CAUSING WEAKENING.
WHILE THE MODELS FORECAST THE SHEAR TO DIMINISH AFTER 48-60 H, THE
CYCLONE OR ITS REMNANTS WILL BE IN AN AREA OF DRY AIR AND
SUBSIDENCE THAT CAUSE CAUSE THE CONVECTION TO DISSIPATE. THE NEW
INTENSITY FORECAST SHOWS THE DEPRESSION BECOMING A TROPICAL STORM
FOR A DAY OR SO, FOLLOWED BY WEAKENING TO A REMNANT LOW BETWEEN
60-72 H. BASED ON THE DYNAMICAL MODELS, THE REMNANT LOW IS FORECAST
TO WEAKEN TO A TROUGH BETWEEN 96-120 H.
FORECAST POSITIONS AND MAX WINDS
INIT 20/0300Z 33.3N 33.2W 30 KT 35 MPH
12H 20/1200Z 33.8N 33.0W 40 KT 45 MPH
24H 21/0000Z 34.0N 32.5W 45 KT 50 MPH
36H 21/1200Z 33.6N 32.4W 40 KT 45 MPH
48H 22/0000Z 32.7N 32.9W 35 KT 40 MPH
60H 22/1200Z 31.6N 33.9W 30 KT 35 MPH
72H 23/0000Z 30.4N 35.6W 25 KT 30 MPH...POST-TROP/REMNT LOW
96H 24/0000Z 29.0N 39.1W 20 KT 25 MPH...POST-TROP/REMNT LOW
120H 25/0000Z...DISSIPATED
FORECASTER BEVEN
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