734
WTPZ42 KNHC 290834
TCDEP2
HURRICANE GENEVIEVE DISCUSSION NUMBER 21
NWS NATIONAL HURRICANE CENTER MIAMI FL EP072026
1100 PM HST TUE JUL 28 2026
THE EYE OF GENEVIEVE IS NO LONGER APPARENT IN CONVENTIONAL SATELLITE
IMAGERY. THE CENTER IS EMBEDDED UNDERNEATH A CENTRAL DENSE OVERCAST
WITH VERY COLD CLOUD TOP TEMPERATURES OF -70 TO -75 DEG C.
PROXY-VISIBLE AND INFRARED SATELLITE IMAGES SHOW THAT NORTHWESTERLY
SHEAR IS RESTRICTING UPPER-LEVEL OUTFLOW ON THE WEST SIDE OF THE
HURRICANE. BASED ON THE DETERIORATING SATELLITE PRESENTATION AND
DECREASING SATELLITE INTENSITY ESTIMATES (INCLUDING A T5.5/102 KT
DVORAK CI FROM TAFB), THE INITIAL INTENSITY IS LOWERED TO 105 KT.
THE 34- AND 50-KT WIND RADII WERE UPDATED BASED ON A RECENT ASCAT-C
PASS OVER THE HURRICANE.
GENEVIEVE IS MOVING WEST-NORTHWESTWARD (285/8 KT) ALONG THE
SOUTHWESTERN PERIPHERY OF A MID-LEVEL RIDGE CENTERED OVER THE
SOUTHWESTERN UNITED STATES AND NORTHERN MEXICO. THIS STEERING RIDGE
IS FORECAST TO STRENGTHEN AND BUILD WESTWARD OVER THE NEXT SEVERAL
DAYS, WHICH SHOULD KEEP GENEVIEVE ON A WEST-NORTHWESTWARD HEADING
WITH SOME INCREASE IN FORWARD SPEED LATE THIS WEEK AND THROUGH THE
WEEKEND. THE NHC TRACK FORECAST IS ESSENTIALLY AN UPDATE OF THE
PREVIOUS ONE, GENERALLY FALLING BETWEEN THE LATEST CORRECTED (HCCA)
AND SIMPLE (TVCN) CONSENSUS AIDS.
THE HURRICANE IS EXPERIENCING MODERATE NORTHWESTERLY SHEAR THAT WILL
PERSIST FOR THE NEXT 12-24 H WHILE IT MOVES OVER GRADUALLY
DECREASING SSTS. BY THE TIME THE SHEAR IS FORECAST TO RELENT,
GENEVIEVE WILL LIKELY HAVE ALREADY CROSSED THE 26 DEG C ISOTHERM AND
MOVED INTO A SOMEWHAT DRIER ENVIRONMENT. THE LATEST INTENSITY
GUIDANCE SUGGESTS ADDITIONAL STRENGTHENING IS UNLIKELY, AND THE
UPDATED NHC PREDICTION SHOWS GENEVIEVE WEAKENING THROUGH THE
FORECAST PERIOD. THE LARGEST DOWNWARD ADJUSTMENTS TO THE FORECAST
WERE MADE IN THE FIRST 48 H, THOUGH NHC STILL LIES ON THE UPPER END
OF THE GUIDANCE. THE SYSTEM IS FORECAST TO FALL BELOW HURRICANE
STRENGTH ON FRIDAY AND BECOME POST-TROPICAL AT DAY 4, WHEN THE GFS
AND ECMWF INDICATE THAT STRENGTHENING SHEAR WILL MAKE IT DIFFICULT
FOR THE SYSTEM TO SUSTAIN ORGANIZED CONVECTION OVER SUB-24 C WATERS.
FORECAST POSITIONS AND MAX WINDS
INIT 29/0900Z 18.4N 118.4W 105 KT 120 MPH
12H 29/1800Z 18.8N 119.8W 100 KT 115 MPH
24H 30/0600Z 19.5N 122.0W 90 KT 105 MPH
36H 30/1800Z 20.2N 124.4W 80 KT 90 MPH
48H 31/0600Z 21.0N 127.0W 70 KT 80 MPH
60H 31/1800Z 21.8N 129.5W 60 KT 70 MPH
72H 01/0600Z 22.5N 132.3W 50 KT 60 MPH
96H 02/0600Z 24.2N 138.1W 40 KT 45 MPH...POST-TROPICAL
120H 03/0600Z 26.0N 143.0W 35 KT 40 MPH...POST-TROPICAL
FORECASTER REINHART
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