929
WTPZ42 KNHC 210246
TCDEP2
HURRICANE NORMA DISCUSSION NUMBER 14
NWS NATIONAL HURRICANE CENTER MIAMI FL EP172023
900 PM MDT FRI OCT 20 2023
NORMA'S SATELLITE DEPICTION HAS NOT CHANGED MUCH OVER THE PAST FEW
HOURS, WITH A TIGHT INNER CORE ON INFRARED IMAGERY. A RECENT SSMI/S
MICROWAVE PASS AT 2306 UTC CONFIRMED THE TIGHT CORE IS WELL INTACT.
THE LAST FEW VISIBLE SATELLITE IMAGES SHOWED THE EYE FEATURE
BECOMING LESS CLOUD FILLED, AND BETTER DEFINED. EARLIER AIR FORCE
HURRICANE HUNTERS FLIGHT-LEVEL AND SFMR WINDS SUPPORTED AN INTENSITY
OF 105 KT. SUBJECT AND OBJECTIVE DVORAK SATELLITE INTENSITY
ESTIMATES FOR THIS CYCLE RANGE FROM 90 TO 105 KT. GIVEN THE
SATELLITE IMAGERY AND THE EARLIER HURRICANE HUNTER DATA, WILL REMAIN
NEAR THE HIGH END OF THE INTENSITY ESTIMATES, WITH AN INITIAL
INTENSITY REMAINING AT 105 KT FOR THIS ADVISORY. THE OUTER RAIN
BANDS OF NORMA ARE SPREADING OVER THE SOUTHERN PORTIONS OF THE BAJA
CALIFORNIA SUR PENINSULA.
THE HURRICANE IS MOVE NORTH-NORTHWESTWARD WITH AN INITIAL MOTION OF
340/8 KT. NORMA IS EXPECTED TO TURN FROM A NORTH-NORTHWEST MOTION
TO NORTHWARD OVER THE NEXT DAY OR SO, WHILE IT MOVES BETWEEN A MID-
TO UPPER-LEVEL TROUGH TO ITS NORTHWEST AND A MID-LEVEL RIDGE TO ITS
EAST. THIS WILL BRING THE CENTER OF NORMA OVER THE SOUTHERN TIP OF
BAJA CALIFORNIA SUR WITHIN THE HURRICANE WARNING ON SATURDAY. THE
TRACK MODELS ARE IN FAIRLY GOOD AGREEMENT WITH LITTLE CHANGE TO THE
PREVIOUS NHC TRACK IN THE SHORT TERM. AFTER MOVING OVER THE BAJA
PENINSULA AND EMERGING INTO THE GULF OF CALIFORNIA, MODELS ARE IN
AGREEMENT WITH A NORTHEAST TO EAST-NORTHEASTWARD TURN TOWARDS THE
COAST OF SINALOA. THERE REMAINS SOME ALONG-TRACK SPEED DIFFERENCES
BETWEEN THE VARIOUS MODEL AIDS. THE NHC FORECAST IS SIMILAR TO THE
PREVIOUS, WITH A SLIGHT NUDGE TO THE RIGHT TOWARDS THE HCCA
CORRECTED CONSENSUS.
NORMA HAS BEEN ABLE TO MAINTAIN AN INNER CORE AND FEND OFF THE
INCREASING SOUTHERLY WIND SHEAR AND DRIER AIR TODAY. THE DRIER AIR
HAS ATTEMPTED TO PENETRATE THE INNER CORE, BUT SO FAR HAS NOT BEEN
ABLE TO DO SO. THE NHC INTENSITY FORECAST IS SIMILAR TO THE
PREVIOUS, WHICH STILL SHOWS SOME WEAKENING, BUT NORMA IS EXPECTED TO
BE A DANGEROUS HURRICANE AS IT MOVES OVER THE BAJA CALIFORNIA SUR
PENINSULA. LAND INTERACTION WITH THE BAJA CALIFORNIA PENINSULA,
ALONG WITH INCREASINGLY DRY AIR AND SOUTHERLY SHEAR, SHOULD RESULT
IN STEADY WEAKENING THROUGH EARLY NEXT WEEK WHILE NORMA APPROACHES
THE WEST COAST OF MAINLAND MEXICO. AFTER THE SYSTEM MOVES INLAND
ALONG THE COAST OF SINALOA ON MONDAY, THE SYSTEM SHOULD RAPIDLY
WEAKEN AND DISSIPATE OVER THE HIGHER TERRAIN.
KEY MESSAGES:
1. NORMA IS EXPECTED TO BRING LIFE-THREATENING HURRICANE CONDITIONS
AND A DANGEROUS STORM SURGE TO PORTIONS OF THE FAR SOUTHERN BAJA
CALIFORNIA PENINSULA WITHIN THE HURRICANE WARNING AREA ON SATURDAY.
PREPARATIONS TO PROTECT LIFE AND PROPERTY SHOULD BE RUSHED TO
COMPLETION.
2. HEAVY RAINS FROM NORMA WILL BEGIN TO IMPACT THE FAR SOUTHERN
PORTIONS OF BAJA CALIFORNIA SUR TONIGHT, CONTINUING THROUGH
SUNDAY, WITH HEAVY RAINS REACHING SINALOA ON SATURDAY. THIS
RAINFALL WILL PRODUCE FLASH AND URBAN FLOODING, ALONG WITH POSSIBLE
MUDSLIDES IN AREAS OF HIGHER TERRAIN.
3. NORMA IS FORECAST TO APPROACH THE WEST COAST OF MEXICO AS A
TROPICAL STORM ON SUNDAY AND SUNDAY NIGHT, AND A TROPICAL STORM
WATCH IS IN EFFECT FOR A PORTION OF THAT AREA.
FORECAST POSITIONS AND MAX WINDS
INIT 21/0300Z 20.8N 109.9W 105 KT 120 MPH
12H 21/1200Z 21.9N 110.1W 100 KT 115 MPH
24H 22/0000Z 23.0N 109.9W 85 KT 100 MPH...INLAND
36H 22/1200Z 23.6N 109.4W 70 KT 80 MPH...OVER WATER
48H 23/0000Z 23.9N 108.6W 60 KT 70 MPH
60H 23/1200Z 24.3N 107.6W 50 KT 60 MPH
72H 24/0000Z 24.8N 106.5W 30 KT 35 MPH...INLAND
96H 25/0000Z...DISSIPATED
FORECASTER KELLY
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