433
WTPZ43 KNHC 291452
TCDEP3
TROPICAL STORM RACHEL DISCUSSION NUMBER 10
NWS NATIONAL HURRICANE CENTER MIAMI FL EP182026
900 AM CST TUE SEP 29 2026
RACHEL IS DEALING WITH AROUND 20 KT OF NORTHEASTERLY WIND SHEAR THIS
MORNING, WITH THE ESTIMATED CENTER POSITION LOCATED ALONG THE FAR
NORTHERN EDGE OF THE CENTRAL DENSE OVERCAST. HOWEVER, A BURST OF
DEEP CONVECTION, WITH CLOUD TOP TEMPERATURES OF AROUND -90 C, ALONG
WITH STRONG UPPER-LEVEL OUTFLOW SUGGESTS THAT THE SYSTEM IS SLOWLY
INTENSIFYING. THE LATEST TAFB DVORAK INTENSITY ESTIMATE WAS 3.5/55
KT, WHILE RECENT OBJECTIVE INTENSITY ESTIMATES FROM UW-CIMSS RANGE
FROM 43-55 KT. GIVEN THE DEEPENING CONVECTION AND THE SLIGHT
INCREASE IN INTENSITY ESTIMATES, THE INITIAL INTENSITY IS SET AT 55
KT FOR THIS ADVISORY.
THE STRONG TROPICAL STORM IS MOVING TOWARD THE WEST-NORTHWEST AROUND
11 KT, STEERED BY A STRONG MID-LEVEL RIDGE CENTERED OVER THE
SOUTH-CENTRAL UNITED STATES. A TURN TOWARD THE NORTHWEST IS EXPECTED
LATER TODAY AS HIGH PRESSURE BUILDS OVER EASTERN MEXICO, FOLLOWED BY
A GRADUAL DECREASE IN FORWARD SPEED AS RACHEL MOVES INTO A REGION
WITH WEAKER STEERING FLOW. BY LATE WEEK, BUILDING HIGH PRESSURE TO
THE NORTHWEST OF THE CYCLONE SHOULD INDUCE A GRADUAL TURN BACK
TOWARD THE WEST-NORTHWEST AND THEN WEST, ACCOMPANIED BY A SLIGHT
INCREASE IN FORWARD SPEED. THE UPDATED FORECAST TRACK IS VERY
SIMILAR TO THE PREVIOUS ADVISORY, REMAINING NEAR THE MIDDLE OF THE
TRACK FORECAST GUIDANCE ENVELOPE THROUGH 48 H AND NEAR THE NORTHERN
END OF THE GUIDANCE THEREAFTER.
DECREASING WIND SHEAR, SUFFICIENTLY WARM SEA SURFACE TEMPERATURES
AND FAVORABLE UPPER-LEVEL DIVERGENCE ARE EXPECTED TO SUPPORT
STRENGTHENING OVER THE NEXT COUPLE OF DAYS, AND RACHEL IS FORECAST
TO BECOME A HURRICANE LATER TODAY. HOWEVER, RACHEL COULD BRIEFLY
MOVE OVER SLIGHTLY COOLER WATERS LEFT IN THE WAKE OF HURRICANE POLO
TONIGHT INTO EARLY WEDNESDAY, WHICH MAY TEMPORARILY LIMIT THE RATE
OF INTENSIFICATION. THEREAFTER, WARMER WATERS SHOULD SUPPORT
ADDITIONAL STRENGTHENING THROUGH LATE THIS WEEK. THE LATEST NHC
INTENSITY FORECAST IS NEAR THE UPPER-END OF THE GUIDANCE ENVELOPE,
ALTHOUGH IT REMAINS SLIGHTLY BELOW THE HCCA SOLUTION.
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 TROPICAL STORM WARNING AREA
TODAY OR TONIGHT. TROPICAL STORM CONDITIONS ARE POSSIBLE IN THE
WATCH AREA TONIGHT OR ON WEDNESDAY.
2. OUTER BANDS FROM RACHEL WILL BRING LOCALLY HEAVY RAINFALL TO
PORTIONS OF COASTAL SOUTHWEST MEXICO THROUGH THURSDAY. THIS RAINFALL
MAY PRODUCE AREAS OF FLOODING AND MUDSLIDES, ESPECIALLY IN REGIONS
OF STEEP TERRAIN.
3. LARGE WAVES COULD PRODUCE LIFE-THREATENING SURF AND RIP CURRENT
CONDITIONS ALONG PORTIONS OF THE SOUTHWESTERN COAST OF MEXICO DURING
THE NEXT SEVERAL DAYS.
FORECAST POSITIONS AND MAX WINDS
INIT 29/1500Z 15.3N 105.0W 55 KT 65 MPH
12H 30/0000Z 16.5N 106.4W 65 KT 75 MPH
24H 30/1200Z 17.9N 107.7W 75 KT 85 MPH
36H 01/0000Z 19.0N 108.8W 85 KT 100 MPH
48H 01/1200Z 19.7N 109.5W 90 KT 105 MPH
60H 02/0000Z 20.1N 110.0W 90 KT 105 MPH
72H 02/1200Z 20.4N 110.6W 95 KT 110 MPH
96H 03/1200Z 20.8N 112.1W 90 KT 105 MPH
120H 04/1200Z 21.1N 114.0W 85 KT 100 MPH
FORECASTER ADAMS
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