285
WTPZ44 KNHC 021437
TCDEP4
TROPICAL STORM PILAR DISCUSSION NUMBER 20
NWS NATIONAL HURRICANE CENTER MIAMI FL EP192023
1000 AM CDT THU NOV 02 2023
PILAR CONTINUES TO HAVE A BURST OF CONVECTION NEAR THE LOW-LEVEL
CENTER THIS MORNING. THERE HAVE BEEN A FEW MICROWAVE PASSES THIS
MORNING, WHICH DEPICT THE OVERALL PULSING NATURE OF THE CONVECTIVE
STRUCTURE OF PILAR. THE SATELLITE INTENSITY ESTIMATES HAVE DECREASED
SLIGHTLY THIS CYCLE. GIVEN THE NATURE OF THE PULSING CONVECTIVE
PATTERN, THE INITIAL INTENSITY LEANS TOWARD THE DVORAK CI-NUMBERS,
WHICH WERE 3.0 AND 2.5 FROM TAFB AND SAB, RESPECTIVELY. THIS
SUPPORTS KEEPING THE INITIAL INTENSITY STEADY AT 45 KT, BUT THIS
COULD BE A LITTLE GENEROUS.
PILAR CONTINUES TO ACCELERATE WESTWARD THIS MORNING AT AN ESTIMATED
MOTION OF 260/13 KT. A STRENGTHENING MID-LEVEL RIDGE IS BUILDING TO
THE NORTH AND NORTHEAST OF PILAR, WHICH WILL STEER THE SYSTEM
WEST-SOUTHWESTWARD THE NEXT FEW DAYS. A SHORTWAVE TROUGH IS FORECAST
TO MOVE IN FROM THE NORTHWEST AND WEAKEN THE MID-LEVEL RIDGE LATE
THIS WEEKEND. THIS WILL RESULT IN PILAR SLOWING DOWN AND TURNING
WEST TO WEST-NORTHWEST EARLY NEXT WEEK. THE MODEL GUIDANCE IS
IN FAIRLY GOOD AGREEMENT WITH THIS SCENARIO, WITH THE MAIN
DIFFERENCE AMONG THE MODELS BEING ALONG-TRACK WITH THE FORWARD
SPEED OF PILAR. THE NHC FORECAST IS SLIGHTLY FASTER THAN THE
PREVIOUS, AND LIES BETWEEN THE SIMPLE AND CORRECTED CONSENSUS AIDS.
THE NEAR TERM INTENSITY FORECAST IS A LITTLE TRICKY GIVEN THE
PULSING CONVECTIVE NATURE OF PILAR AND THE INTERACTION WITH STRONG
LOW-LEVEL NORTHERLY WINDS ASSOCIATED WITH AN ONGOING GULF OF
TEHUANTEPEC GAP WIND EVENT. THE GAP WIND FLOW COULD INTRODUCE SOME
DRIER AIR INTO PILAR'S CIRCULATION, WHICH MAY BRIEFLY DISRUPT ITS
CONVECTIVE ORGANIZATION. LATER THIS WEEKEND, THE SYSTEM IS FORECAST
TO MOVE OVER WARM SEA SURFACE TEMPERATURES WITH WEAK TO MODERATE
VERTICAL WIND SHEAR. THERE IS SOME SPREAD IN THE INTENSITY GUIDANCE
BETWEEN 36-72H WITH SOME OF THE HURRICANE REGIONAL MODELS SHOWING
STRENGTHENING, WHILE SOME OF THE GLOBAL MODELS SHOW LITTLE CHANGE IN
INTENSITY. GIVEN THE FAVORABLE PARAMETERS AND THE GUIDANCE TRENDS,
THE NHC INTENSITY FORECAST IS SLIGHTLY HIGHER THAN THE PREVIOUS AT
THESE TIME RANGES, BUT STILL BELOW THE HWRF, HAFS-A AND HCCA
CORRECTED CONSENSUS. TOWARDS THE END OF THE FORECAST PERIOD, PILAR
WILL ENCOUNTER A LESS FAVORABLE ENVIRONMENT WITH INCREASING
SOUTHWESTERLY SHEAR AND DRIER AIR. GIVEN THE SMALL SIZE OF PILAR,
INTENSITY FLUCTUATIONS ARE POSSIBLE THROUGHOUT THE FORECAST PERIOD.
FORECAST POSITIONS AND MAX WINDS
INIT 02/1500Z 11.9N 95.2W 45 KT 50 MPH
12H 03/0000Z 11.2N 97.7W 45 KT 50 MPH
24H 03/1200Z 10.5N 100.9W 40 KT 45 MPH
36H 04/0000Z 10.1N 104.0W 40 KT 45 MPH
48H 04/1200Z 10.2N 106.8W 45 KT 50 MPH
60H 05/0000Z 10.5N 109.2W 45 KT 50 MPH
72H 05/1200Z 10.9N 111.3W 45 KT 50 MPH
96H 06/1200Z 11.9N 114.5W 40 KT 45 MPH
120H 07/1200Z 13.1N 117.3W 35 KT 40 MPH
FORECASTER KELLY
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