208
WTPZ45 KNHC 120251
TCDEP5
HURRICANE SIMON DISCUSSION NUMBER 19
NWS NATIONAL HURRICANE CENTER MIAMI FL EP202026
800 PM MST SUN OCT 11 2026
SIMON IS SHOWING SIGNS OF WEAKENING THIS EVENING, LIKELY DUE TO ITS
PROLONGED CLOSE PROXIMITY TO THE MEXICAN COASTLINE AND THE
ASSOCIATED NEGATIVE AFFECTS OF NEARBY MOUNTAINOUS TERRAIN. INFRARED
SATELLITE IMAGERY INDICATES WARMING CLOUD TOPS WITHIN THE CONVECTION
IN THE NORTHEASTERN QUADRANT, WITH MID-LEVEL DRY AIR BEGINNING TO
WRAP AROUND THE WESTERN SIDE OF THE CYCLONE. RECENT OBJECTIVE DVORAK
INTENSITY ESTIMATES HAVE DECREASED OVER THE PAST SEVERAL HOURS AND
RANGE FROM 99-110 KT. BASED ON THE DETERIORATING SATELLITE
PRESENTATION AND THE LOWER INTENSITY ESTIMATES, THE INITIAL
INTENSITY IS SET AT 105 KT FOR THIS ADVISORY.
THE MAJOR HURRICANE IS MOVING SLOWLY NORTH-NORTHWESTWARD, STEERED BY
A MID-LEVEL RIDGE CENTERED OVER THE SOUTH-CENTRAL UNITED STATES.
SIMON IS FORECAST TO TRACK PARALLEL TO THE COAST OF WEST-CENTRAL
MEXICO OVER THE NEXT DAY OR SO. HOWEVER, ITS CONTINUED CLOSE
PROXIMITY TO LAND WILL LIKELY BRING HURRICANE CONDITIONS TO PORTIONS
OF THE WARNING AREA, PARTICULARLY NEAR CABO CORRIENTES, EVEN THOUGH
THE CORE IS FORECAST TO REMAIN JUST OFFSHORE. AROUND MIDWEEK, A
STRONG UPPER-LEVEL LOW MOVING ACROSS THE WESTERN UNITED STATES IS
EXPECTED TO INDUCE A TURN TOWARD THE NORTH AND THEN NORTHEAST.
ALTHOUGH THERE REMAINS SOME MODEL SPREAD, AN INCREASING NUMBER OF
THE HURRICANE REGIONAL MODELS AND CONSENSUS AIDS, INCLUDING HCCA,
BRING SIMON ONSHORE AROUND MIDWEEK. THE LATEST NHC FORECAST IS VERY
SIMILAR TO THE PREVIOUS ADVISORY, SHOWING SIMON MOVING INLAND AND
DISSIPATING IN THE DAY 3-4 PERIOD.
GRADUAL WEAKENING IS EXPECTED DUE TO THE PROXIMITY TO THE
MOUNTAINOUS TERRAIN, WHICH COULD FURTHER DISRUPT THE HURRICANE'S
STRUCTURE ALONG ITS EASTERN SIDE. A SLIGHT INCREASE IN WIND SHEAR
AND THE ENTRAINMENT OF DRIER MID-LEVEL AIR SHOULD FURTHER CONTRIBUTE
TO THE WEAKENING TREND. HOWEVER, AS SIMON TURNS NORTHWARD THEN
NORTHEASTWARD AROUND MIDWEEK, IT IS FORECAST TO MOVE OVER VERY WARM
WATERS OF 31-32 C, WHICH COULD LIMIT FURTHER WEAKENING BEFORE
LANDFALL. THE LATEST NHC FORECAST HAS BEEN NUDGED UPWARD SLIGHTLY
BEYOND 12 H, WITH SIMON EXPECTED TO MAINTAIN HURRICANE STRENGTH
THROUGH LANDFALL. THIS FORECAST LIES NEAR THE MIDDLE OF THE
INTENSITY GUIDANCE ENVELOPE. RAPID WEAKENING IS EXPECTED ONCE SIMON
MOVES INLAND, AND DISSIPATION IS FORECAST BY 96 H.
KEY MESSAGES:
1. CATASTROPHIC WIND AND LIFE-THREATENING STORM SURGE IMPACTS ARE
LIKELY ALONG A PORTION OF THE WEST-CENTRAL COAST OF MEXICO, AND A
HURRICANE WARNING IS IN EFFECT FROM PLAYA PERULA TO EL ROBLITO.
RESIDENTS SHOULD CONTINUE TO SHELTER IN A SAFE ROOM TO RIDE OUT THE
STORM AS THE MOST SIGNIFICANT HAZARDS ARE ONGOING.
2. SIMON IS EXPECTED TO APPROACH THE COAST OF WESTERN MEXICO LATER
THIS WEEK, WHERE HURRICANE CONDITIONS ARE POSSIBLE. A HURRICANE
WATCH IS IN EFFECT FROM EL ROBLITO TO BAHIA TEMPEHUAYA.
3. HEAVY RAINFALL ASSOCIATED WITH SIMON WILL IMPACT PORTIONS OF
SOUTHWESTERN AND WEST-CENTRAL MEXICO OVER THE NEXT FEW DAYS. THIS
RAINFALL WILL PRODUCE LIFE-THREATENING FLOODING AND MUDSLIDES,
ESPECIALLY IN AREAS OF STEEP TERRAIN.
4. SWELLS WILL AFFECT PORTIONS OF THE SOUTHWESTERN AND WEST-CENTRAL
COAST OF MEXICO OVER THE NEXT FEW DAYS. THESE SWELLS ARE LIKELY TO
CAUSE LIFE-THREATENING SURF AND RIP CURRENT CONDITIONS. PLEASE
CONSULT PRODUCTS FROM YOUR LOCAL WEATHER OFFICE.
FORECAST POSITIONS AND MAX WINDS
INIT 12/0300Z 19.8N 106.0W 105 KT 120 MPH
12H 12/1200Z 20.5N 106.3W 95 KT 110 MPH
24H 13/0000Z 21.2N 106.8W 85 KT 100 MPH
36H 13/1200Z 21.8N 107.1W 80 KT 90 MPH
48H 14/0000Z 22.4N 107.0W 80 KT 90 MPH
60H 14/1200Z 23.0N 106.7W 80 KT 90 MPH
72H 15/0000Z 23.4N 106.4W 65 KT 75 MPH...INLAND
96H 16/0000Z 24.0N 105.7W 30 KT 35 MPH...POST-TROP/INLAND
120H 17/0000Z...DISSIPATED
FORECASTER ADAMS/CANGIALOSI
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