833
WTPZ43 KNHC 300849
TCDEP3
HURRICANE RACHEL DISCUSSION NUMBER 13
NWS NATIONAL HURRICANE CENTER MIAMI FL EP182026
200 AM MST WED SEP 30 2026
RACHEL IS BECOMING BETTER ORGANIZED AS THE NORTH-NORTHEASTERLY
VERTICAL WIND SHEAR OVER THE SYSTEM APPEARS TO BE RELAXING. AFTER
STRENGTHENING INTO A HURRICANE AROUND 0600 UTC, THE SYSTEM IS
DEVELOPING BETTER-DEFINED CONVECTIVE BANDING FEATURES,
ESPECIALLY OVER THE WESTERN QUADRANT OF THE CIRCULATION. DEEP
CONVECTION REMAINS VERY INTENSE, WITH NUMEROUS CLOUD TOPS AS COLD
AS -80 DEG C. A NOAA HURRICANE HUNTER AIRCRAFT FLYING A RESEARCH
MISSION INTO RACHEL MEASURED 84-KT WINDS AT THE 700 MB FLIGHT
LEVEL. BASED ON THIS OBSERVATION AND THE INCREASED ORGANIZATION ON
SATELLITE IMAGES, THE ADVISORY INTENSITY IS SET TO 75 KT. THIS IS
SOMEWHAT HIGHER THAN THE SUBJECTIVE DVORAK ESTIMATE AND OBJECTIVE
ESTIMATES FROM UW-CIMSS.
THE FORWARD SPEED HAS SLOWED SOMEWHAT AND THE CURRENT MOTION
ESTIMATE IS 315/9 KT. RACHEL CONTINUES TO MOVE ALONG THE
SOUTHWESTERN SIDE OF A MID-TROPOSPHERIC RIDGE OVER NORTHERN AND
CENTRAL MEXICO. THE RIDGE IS WEAKENING DUE TO THE PASSAGE OF A
MID- TO UPPER-LEVEL TROUGH/LOW OVER THE SOUTHERN UNITED STATES, AND
THIS IS GRADUALLY SLOWING THE STEERING CURRENT. AS THE LOW LIFTS
NORTHWARD 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 TOWARD THE WEST-NORTHWEST AND PASS WELL
SOUTH OF THE BAJA CALIFORNIA PENINSULA BEFORE CONTINUING WESTWARD
AWAY FROM LAND. THE OFFICIAL TRACK FORECAST IS SIMILAR TO, BUT
SLIGHTLY SLOWER THAN, THE PREVIOUS NHC PREDICTION. THIS IS A BLEND
OF THE LATEST HFIP CORRECTED CONSENSUS APPROACH (HCCA) AND GOOGLE
DEEPMIND GUIDANCE.
GIVEN THE DECREASE IN VERTICAL SHEAR, AND EXPECTED PASSAGE OVER
VERY WARM WATERS, SIGNIFICANT STRENGTHENING SEEMS LIKELY DURING THE
NEXT 24-36 HOURS. THE SHIPS RAPID INTENSIFICATION (RI) GUIDANCE
INDICATES A SUBSTANTIALLY HIGHER THAN NORMAL PROBABILITY OF RI.
THE OFFICIAL INTENSITY FORECAST ANTICIPATES THAT RACHEL WILL
QUICKLY STRENGTHEN INTO A MAJOR HURRICANE BY TOMORROW IF NOT
SOONER. THIS IS ALSO SIMILAR TO THE LATEST HCCA PREDICTION.
BEYOND 48 HOURS, DRIER LOW- TO MID-LEVEL AIR COULD CAUSE SOME
WEAKENING. THE NHC INTENSITY FORECASTS IS ON THE HIGH SIDE OF THE
MODEL GUIDANCE ENVELOPE.
THE OUTER WIND RADII WERE ADJUSTED BASED ON DATA FROM RECENT
ASCAT-B/C OVERPASSES.
KEY MESSAGES:
1. ALTHOUGH THE CORE OF RACHEL IS FORECAST TO REMAIN OFFSHORE OF
MEXICO, TROPICAL-STORM-FORCE WINDS ARE EXPECTED ALONG A PORTION OF
THE COAST OF SOUTHWESTERN MEXICO IN THE WARNING AREA THIS MORNING.
2. OUTER BANDS FROM RACHEL WILL BRING LOCALLY HEAVY RAINFALL TO
PORTIONS OF COASTAL SOUTHWEST MEXICO THROUGH THURSDAY. 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 30/0900Z 17.6N 107.2W 75 KT 85 MPH
12H 30/1800Z 18.4N 108.1W 90 KT 105 MPH
24H 01/0600Z 19.2N 109.1W 100 KT 115 MPH
36H 01/1800Z 19.5N 109.7W 105 KT 120 MPH
48H 02/0600Z 19.7N 110.4W 105 KT 120 MPH
60H 02/1800Z 19.9N 111.1W 100 KT 115 MPH
72H 03/0600Z 20.1N 112.2W 90 KT 105 MPH
96H 04/0600Z 20.4N 114.3W 90 KT 105 MPH
120H 05/0600Z 20.8N 116.3W 85 KT 100 MPH
FORECASTER PASCH
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