304
WTPZ43 KNHC 271444
TCDEP3
TROPICAL DEPRESSION EIGHTEEN-E DISCUSSION NUMBER 2
NWS NATIONAL HURRICANE CENTER MIAMI FL EP182026
900 AM CST SUN SEP 27 2026
DEEP CONVECTION IS GRADUALLY BECOMING BETTER ORGANIZED IN
ASSOCIATION WITH THE DEPRESSION. THERE IS EVIDENCE OF BANDING OVER
THE NORTHERN AND WESTERN PORTIONS OF THE CIRCULATION, ALTHOUGH
THERE APPEARS TO BE SOME EASTERLY SHEAR OVER THE SYSTEM. TAFB
PROVIDED A DVORAK CLASSIFICATION OF T2.5/35 KT AND OBJECTIVE
ESTIMATES ARE IN THE 30-35 KT RANGE. GIVEN THE FRAGMENTED NATURE
OF THE CONVECTIVE BANDING, THE INITIAL INTENSITY IS HELD AT 30 KT.
A VERY RECENT ARRIVING WSF-M MICROWAVE OVERPASS WAS VERY HELPFUL
IN LOCATING THE CENTER, WHICH WAS A LITTLE NORTH OF THE PREVIOUS
ESTIMATE.
THE INITIAL MOTION APPEARS TO BE 295/4 KT, A LITTLE SLOWER THAN
ESTIMATED IN THE FIRST ADVISORY. THE DEPRESSION IS FORECAST TO
MOVE FASTER TOWARD THE WEST-NORTHWEST, TO THE SOUTH OF A
DEEP-LAYER RIDGE OVER MEXICO DURING THE NEXT SEVERAL DAYS. THE
TRACK GUIDANCE IS IN GOOD AGREEMENT ON THE CORE OF THE SYSTEM
STAYING WELL SOUTH OF THE COAST OF SOUTHERN MEXICO, AND THE NHC
TRACK FORECAST FOLLOWS A BLEND OF THE GDM CONSENSUS AID AND THE HFIP
CORRECTED CONSENSUS. THE NEW TRACK WAS ADJUSTED SLIGHTLY NORTH OF
THE PREVIOUS ADVISORY DUE TO THE MORE NORTHWARD INITIAL POSITION.
MODERATE EASTERLY SHEAR OVER THE SYSTEM IS LIKELY TO KEEP
SIGNIFICANT STRENGTHENING IN CHECK DURING THE NEXT 12 HOURS, BUT THE
SYSTEM IS LIKELY TO BECOME A TROPICAL STORM DURING THAT TIME. BY
LATE TONIGHT AND MONDAY, A FASTER RATE OF STRENGTHENING IS EXPECTED
AS SHEAR DECREASES AND THE SYSTEM MOVES OVER WARM SSTS. MUCH OF
THE INTENSITY GUIDANCE SHOWS THE SYSTEM BECOMING A HURRICANE IN
ABOUT 48 HOURS, AND THE NHC WIND SPEED FORECAST FOLLOWS SUIT.
AROUND 72 HOURS, THERE IS SOME UNCERTAINTY WITH REGARDS TO SSTS
WITH THE TRACK POTENTIALLY MOVING OVER THE COOL WAKE OF HURRICANE
POLO. THEREFORE, THE INTENSITY FORECAST DURING THAT PERIOD CALLS
FOR THE INTENSITY TO LEVEL OFF, WHICH IS SIMILAR TO WHAT IS SHOWN
BY THE HFIP CORRECTED CONSENSUS.
FORECAST POSITIONS AND MAX WINDS
INIT 27/1500Z 12.7N 98.6W 30 KT 35 MPH
12H 28/0000Z 13.0N 99.2W 35 KT 40 MPH
24H 28/1200Z 13.7N 100.5W 45 KT 50 MPH
36H 29/0000Z 14.6N 102.4W 55 KT 65 MPH
48H 29/1200Z 15.5N 104.2W 65 KT 75 MPH
60H 30/0000Z 16.5N 106.0W 70 KT 80 MPH
72H 30/1200Z 17.3N 107.4W 75 KT 85 MPH
96H 01/1200Z 18.7N 109.2W 80 KT 90 MPH
120H 02/1200Z 19.4N 110.0W 80 KT 90 MPH
FORECASTER BROWN
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