878
WTPZ43 KNHC 302042
TCDEP3
HURRICANE RACHEL DISCUSSION NUMBER 15
NWS NATIONAL HURRICANE CENTER MIAMI FL EP182026
200 PM MST WED SEP 30 2026
DATA FROM A NOAA HURRICANE HUNTER AIRCRAFT ALONG WITH CONVENTIONAL
AND MICROWAVE SATELLITE IMAGERY SHOWS THAT RACHEL HAS BEEN
RE-ORGANIZING FOR THE PAST SEVERAL HOURS. MICROWAVE DATA NEAR 13Z
INDICATED THAT THE CYCLONE HAD A RAGGED INNER CORE WITH NO
ORGANIZED EYEWALL. DURING THE TIME THAT THE AIRCRAFT HAS BEEN IN THE
STORM, THE EYEWALL HAS GOTTEN BETTER DEFINED IN THE SOUTHEASTERN
SEMICIRCLE AND THE RADIUS OF MAXIMUM WINDS IS GETTING SMALLER. THE
MAXIMUM 700-MB FLIGHT-LEVEL WINDS REPORTED BY THE AIRCRAFT HAS BEEN
82 KT, AND THE CENTRAL PRESSURE IS CURRENTLY NEAR 978 MB. BASED
MAINLY ON THE AIRCRAFT DATA, THE INITIAL INTENSITY IS HELD AT 75
KT. IT SHOULD BE NOTED THAT SHEAR ANALYSES SHOW THAT THE HURRICANE
IS STILL BE AFFECTED BY ABOUT 20 KT OF NORTHEASTERLY VERTICAL WIND
SHEAR.
THE INITIAL MOTION IS STILL NORTHWESTWARD OR 315/7 KT. RACHEL
CONTINUES TO MOVE ALONG THE SOUTHWESTERN SIDE OF A MID-TROPOSPHERIC
RIDGE OVER NORTHERN AND CENTRAL MEXICO. THIS RIDGE IS WEAKENING
DUE TO THE EFFECTS OF A LARGE MID- TO UPPER-LEVEL TROUGH SEEN IN
WATER VAPOR IMAGERY OVER THE SOUTHWESTERN UNITED STATES AND
NORTHWESTERN MEXICO. AS THIS TROUGH MOVES NORTHEASTWARD AND
WEAKENS DURING THE NEXT COUPLE OF DAYS, THIS SHOULD ALLOW ANOTHER
RIDGE TO BUILD TO THE NORTH OF THE TROPICAL CYCLONE. AS A RESULT,
RACHEL IS FORECAST TO TURN WEST-NORTHWEST AND PASS WELL SOUTH OF
THE BAJA CALIFORNIA PENINSULA BEFORE CONTINUING WESTWARD AWAY FROM
LAND. THE NEW FORECAST TRACK IS A LITTLE TO THE NORTH OF THE
PREVIOUS TRACK FOR THE FIRST 60 H, AND THEREAFTER IS SIMILAR TO THE
PREVIOUS TRACK.
ENVIRONMENTAL CONDITIONS APPEAR FAVORABLE FOR STRENGTHENING THROUGH
AT LEAST 48 H, AND RAPID STRENGTHENING IS A POSSIBILITY IF THE
TIGHTER INNER CORE THAT RACHEL IS TRYING TO DEVELOP MAINTAINS
ITSELF. THUS, THE EARLY PORTION OF THE INTENSITY FORECAST KEEPS THE
SAME RATE OF INTENSIFICATION TO A MAJOR HURRICANE AS THE PREVIOUS
FORECASTS. HOWEVER, THERE REMAINS TWO POSSIBLE NEGATIVE INFLUENCES
INCLUDING THE ONGOING SHEAR AND RACHEL CROSSING A TRACK OF COOLER
WATER LEFT BY POLO. LATER ON THE FORECAST PERIOD, DECREASING SEA
SURFACE TEMPERATURES UNDER THE FORECAST TRACK AND DRY AIR
ENTRAINMENT COULD CAUSE SOME WEAKENING. THE NEW INTENSITY FORECAST
IS AGAIN AN UPDATE OF THE PREVIOUS FORECAST, AND IT LIES NEAR THE
UPPER EDGE OF THE INTENSITY GUIDANCE.
KEY MESSAGES:
1. ALTHOUGH THE CORE OF RACHEL IS FORECAST TO REMAIN OFFSHORE OF
MEXICO, WIND GUSTS OF TROPICAL-STORM FORCE ARE POSSIBLE ALONG
PORTIONS OF THE COAST OF SOUTHWESTERN MEXICO THROUGH TONIGHT.
2. OUTER BANDS FROM RACHEL WILL CONTINUE TO PRODUCE LOCALLY HEAVY
RAINFALL ACROSS PORTIONS OF COASTAL SOUTHWEST MEXICO. THIS RAINFALL
MAY PRODUCE LIFE-THREATENING FLOODING AND MUDSLIDES, ESPECIALLY IN
AREAS OF STEEP TERRAIN.
3. LARGE WAVES COULD PRODUCE LIFE-THREATENING SURF AND RIP CURRENT
CONDITIONS ALONG THE SOUTHWESTERN AND WEST-CENTRAL COAST OF MEXICO
AND THE SOUTHERN BAJA CALIFORNIA PENINSULA DURING THE NEXT SEVERAL
DAYS.
FORECAST POSITIONS AND MAX WINDS
INIT 30/2100Z 18.8N 108.0W 75 KT 85 MPH
12H 01/0600Z 19.1N 108.6W 90 KT 105 MPH
24H 01/1800Z 19.6N 109.2W 100 KT 115 MPH
36H 02/0600Z 19.9N 109.9W 105 KT 120 MPH
48H 02/1800Z 20.0N 110.8W 105 KT 120 MPH
60H 03/0600Z 20.1N 111.8W 100 KT 115 MPH
72H 03/1800Z 20.3N 113.0W 90 KT 105 MPH
96H 04/1800Z 20.5N 115.3W 90 KT 105 MPH
120H 05/1800Z 20.6N 117.8W 85 KT 100 MPH
FORECASTER BEVEN
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