679
WTPZ45 KNHC 232049
TCDEP5
HURRICANE JOHN DISCUSSION NUMBER 6
NWS NATIONAL HURRICANE CENTER MIAMI FL EP102024
300 PM CST MON SEP 23 2024
JOHN CONTINUES TO RAPIDLY STRENGTHEN. THE LATEST SUBJECTIVE DVORAK
INTENSITY ESTIMATES RANGE FROM 65 TO 77 KT, WHILE THE LATEST
OBJECTIVE INTENSITY ESTIMATES ARE A LITTLE HIGHER, IN THE 79 TO 90
KT RANGE. ON INFRARED SATELLITE IMAGERY, THE AREA OF COLD CLOUD
TOPS CONTINUES TO GROW, AND THE INNER CORE IS BECOMING MORE
SYMMETRIC. THE LATEST VISIBLE IMAGES HAVE SHOWN HINTS OF A SMALL
EYE, THAT HAS BECOME A LITTLE MORE APPARENT IN THE LAST FEW HOURS.
BASED ON THE ABOVE DATA AND RECENT SATELLITE TRENDS, THE INITIAL
INTENSITY IS INCREASED TO 85 KT, MAKING JOHN A CATEGORY 2 HURRICANE.
ENVIRONMENTAL PARAMETERS CONTINUE TO BE RIPE FOR ADDITIONAL RAPID
INTENSIFICATION, WITH VERY WARM OCEAN TEMPERATURES, WEAK VERTICAL
WIND SHEAR AND A MOIST ATMOSPHERE. THE ONLY POTENTIAL LIMITING
FACTOR COULD BE HOW JOHN MIGHT INTERACT WITH THE MOUNTAINOUS
TOPOGRAPHY OF MEXICO AS THE HURRICANE APPROACHES THE COASTLINE. THE
DSHIPS AND LGEM STATISTICAL INTENSITY MODELS REMAIN AT THE HIGHER
END OF THE GUIDANCE ENVELOPE AND SHOW JOHN BECOMING A MAJOR
HURRICANE AS IT APPROACHES THE COAST. THE EC SHIPS RAPID INTENSITY
INDEX IS DEPICTING A HIGH LIKELIHOOD OF CONTINUED RAPID
INTENSIFICATION OVER NEXT 12 HOURS. THE LATEST NHC FORECAST IS NEAR
THE HIGH END OF THE INTENSITY GUIDANCE AND CONTINUES TO SHOW JOHN
STRENGTHENING TO A 105-KT HURRICANE. IT IS POSSIBLE THAT JOHN COULD
PEAK EVEN HIGHER THAN SHOWN BELOW BETWEEN THE 12 H FORECAST POINT
AND WHEN IT REACHES THE COAST.
JOHN CONTINUES TO MOVE DUE NORTHWARD, NOW AT 5 KT. THE CURRENT
MOTION AND THE LATEST MODEL GUIDANCE HAS AGAIN NECESSITATED A
WESTWARD TRACK SHIFT TO THE NHC FORECAST. GIVEN THE UPDATED TRACK
FORECAST, THE GOVERNMENT OF MEXICO HAS EXTENDED THE HURRICANE
WARNING WESTWARD.
KEY MESSAGES:
1. JOHN IS EXPECTED TO CONTINUE RAPIDLY INTENSIFYING, AND IS
FORECAST TO BECOME A MAJOR HURRICANE BEFORE THE CENTER REACHES THE
COAST OF SOUTHERN MEXICO WITHIN THE HURRICANE WARNING AREA TONIGHT
OR EARLY TUESDAY. DAMAGING HURRICANE-FORCE WINDS AND A
LIFE-THREATENING STORM SURGE ARE EXPECTED WITHIN PORTIONS OF THE
HURRICANE WARNING AREA.
2. JOHN WILL BRING VERY HEAVY RAINFALL TO COASTAL PORTIONS OF
SOUTHERN MEXICO THROUGH THIS WEEK. THIS HEAVY RAINFALL WILL LIKELY
CAUSE SIGNIFICANT AND POSSIBLY CATASTROPHIC, LIFE-THREATENING FLASH
FLOODING AND MUDSLIDES TO THE MEXICAN STATES OF CHIAPAS, OAXACA, AND
SOUTHEAST GUERRERO, PARTICULARLY IN AREAS NEAR THE COAST.
FORECAST POSITIONS AND MAX WINDS
INIT 23/2100Z 15.5N 98.5W 85 KT 100 MPH
12H 24/0600Z 16.0N 98.3W 105 KT 120 MPH
24H 24/1800Z 16.5N 98.3W 65 KT 75 MPH...INLAND
36H 25/0600Z 16.7N 98.4W 30 KT 35 MPH...POST-TROP/INLAND
48H 25/1800Z...DISSIPATED
FORECASTER HAGEN
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