636
WTPZ44 KNHC 312035
TCDEP4
TROPICAL STORM PILAR DISCUSSION NUMBER 13
NWS NATIONAL HURRICANE CENTER MIAMI FL EP192023
400 PM CDT TUE OCT 31 2023
SATELLITE IMAGERY SHOWS THAT PILAR'S CENTER REMAINS EXPOSED ON THE
SOUTHEAST SIDE OF THE MAIN CONVECTIVE PLUME. EARLIER AMSR2 AND
SSMI/S MICROWAVE IMAGERY DEPICTS SOME PARTIAL BANDING FEATURES
WITHIN THE NORTHERN SEMI-CIRCLE. SCATTEROMETER ASCAT-B AND -C PASSES
THIS AFTERNOON SHOWS SATELLITE DERIVED WINDS ARE AROUND 40 TO 45
KNOTS. THESE VALUES ARE IN GOOD AGREEMENT WITH THE LATEST DVORAK
SATELLITE INTENSITY ESTIMATES FROM BOTH TAFB AND SAB, T/3.0 OR 45
KNOTS. THEREFORE, GIVEN THE COMBINATION OF DATA THIS THE
INITIAL INTENSITY REMAINS AT 45 KT FOR THIS ADVISORY.
PILAR IS MOVING SLOWLY EAST-NORTHEASTWARD OR 060/3 KT. THE STORM IS
FORECAST TO MOVE VERY LITTLE TONIGHT AS THE STEERING CURRENTS OVER
THE FAR EASTERN PACIFIC COLLAPSE. A MID-LEVEL RIDGE IS THEN FORECAST
TO BUILD TO THE NORTH AND NORTHEAST OF PILAR, WHICH SHOULD CAUSE THE
STORM TO BEGIN MOVING WEST-SOUTHWESTWARD. AS THE MID-LEVEL RIDGE
CONTINUES TO BUILD WESTWARD, PILAR WILL BE STEERED ON A
WEST-SOUTHWESTWARD TO WESTWARD MOTION ALONG THE SOUTHERN SIDE OF THE
RIDGE. THE LATEST NHC TRACK FORECAST IS SIMILAR TO THE PREVIOUS
ADVISORY AND LIES NEAR THE LATEST CONSENSUS AIDS. THE THREAT OF
TROPICAL-STORM-FORCE WINDS SHOULD BEGIN TO DIMINISH AS PILAR STARTS
MOVING WESTWARD, BUT THE RISK OF HEAVY RAIN AND FLASH-FLOODING IS
EXPECTED TO CONTINUE OVER PORTIONS OF CENTRAL AMERICA OVER THE NEXT
COUPLE OF DAYS.
SOME SLIGHT STRENGTHENING IS POSSIBLE DURING THE NEXT DAY OR SO AS
THE STORM IS LOCATED OVER WARM SEA SURFACE TEMPERATURES AND MODERATE
VERTICAL WIND SHEAR. IN ABOUT 2 TO 3 DAYS VERTICAL WIND SHEAR IS
FORECAST TO WEAKEN, BUT DRY AIR FROM A GAP WIND EVENT FROM THE GULF
OF TEHUANTEPEC MAY LIMIT INTENSIFICATION. TOWARDS THE END OF THE
PERIOD, THE ENVIRONMENTAL CONDITIONS MAY BECOME A LITTLE MORE
CONDUCIVE AND THE OFFICIAL FORECAST DEPICTS STRENGTHENING ONCE
AGAIN. THE NHC INTENSITY FORECAST LIES NEAR THE CORRECTED HCCA
CONSENSUS AIDS.
KEY MESSAGES:
1. HEAVY RAINS FROM PILAR WILL PRODUCE FLASH AND URBAN FLOODING,
ALONG WITH MUDSLIDES IN AREAS OF HIGHER TERRAIN OF THE PACIFIC COAST
OF CENTRAL AMERICA FROM SOUTHERN EL SALVADOR, ACROSS SOUTHERN
HONDURAS, WESTERN NICARAGUA INTO NORTHERN COSTA RICA THROUGH
WEDNESDAY.
2. TROPICAL STORM CONDITIONS ARE POSSIBLE ALONG PORTIONS OF THE
PACIFIC COAST OF EL SALVADOR, HONDURAS, AND NICARAGUA, WHERE A
TROPICAL STORM WATCH REMAINS IN EFFECT.
3. SWELLS GENERATED BY PILAR WILL CONTINUE TO AFFECT THE PACIFIC
COAST OF CENTRAL AMERICA DURING THE NEXT FEW DAYS. THESE SWELLS ARE
LIKELY TO CAUSE LIFE-THREATENING SURF AND RIP CURRENT CONDITIONS.
FORECAST POSITIONS AND MAX WINDS
INIT 31/2100Z 11.4N 89.5W 45 KT 50 MPH
12H 01/0600Z 11.5N 89.7W 50 KT 60 MPH
24H 01/1800Z 11.5N 90.5W 50 KT 60 MPH
36H 02/0600Z 11.2N 92.2W 50 KT 60 MPH
48H 02/1800Z 10.7N 94.5W 45 KT 50 MPH
60H 03/0600Z 10.1N 97.2W 45 KT 50 MPH
72H 03/1800Z 9.6N 100.0W 45 KT 50 MPH
96H 04/1800Z 9.5N 105.3W 45 KT 50 MPH
120H 05/1800Z 10.1N 109.3W 50 KT 60 MPH
FORECASTER KELLY
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