012
WTPZ41 KNHC 140254
TCDEP1
TROPICAL STORM TRUDY DISCUSSION NUMBER 3
NWS NATIONAL HURRICANE CENTER MIAMI FL EP212026
900 PM CST TUE OCT 13 2026
TROPICAL STORM TRUDY HAS A FAIRLY LARGE CIRCULATION WITH SEVERAL
OUTER BANDING FEATURES PROPAGATING OUTWARD IN A MANNER CONSISTENT
WITH A DIURNAL PULSE. DESPITE THE LARGE APPARENT SIZE, WHICH DWARFS
NEARBY HURRICANE SIMON, THE CORE OF TRUDY IS ANALYZED TO BE SOMEWHAT
COMPACT WITH TROPICAL-STORM-FORCE WINDS LIMITED TO THE NORTHERN
SEMICIRCLE OF THE CIRCULATION AND NO FARTHER THAN 60 N MI FROM THE
CENTER. IT WAS A BIT DIFFICULT TO ANALYZE THE INITIAL CENTER
POSITION FOR THIS ADVISORY. LATE ARRIVING OCEANSAT-3 SCATTEROMETER
DATA AND AMSR3 MICROWAVE IMAGERY SUGGEST THAT THE CENTER OF TRUDY
MAY HAVE BEEN SOMEWHAT NORTH OF THE BEST TRACK POSITION EARLIER
TODAY. THE OBJECTIVE AND SUBJECTIVE SATELLITE FIXES ALSO RANGE BY
SEVERAL DEGREES. THE INITIAL POSITION BLENDS THESE AVAILABLE DATA
WITH THE LAST FEW VISIBLE SATELLITE IMAGES OF THE DAY AND MAINTAINS
CONTINUITY WITH THE PREVIOUS FORECAST TRACK. TRUDY'S INTENSITY WAS A
MUCH EASIER ANALYSIS, AND IS INCREASED TO 40 KT FOR THIS ADVISORY,
WHICH BLENDS THE OBJECTIVE SATELLITE INTENSITY ESTIMATES FROM
UW-CIMSS, THE SUBJECTIVE DVORAK CLASSIFICATION FROM TAFB, AND RECENT
SHORT-TERM TRENDS IN THE SATELLITE PRESENTATION OF THE SYSTEM.
THE TRACK FORECAST IS DIFFICULT AND UNCERTAIN, WITH HIGHER THAN
NORMAL SPREAD IN THE GUIDANCE FROM 72 H ONWARD. THE INITIAL MOTION
OF TRUDY IS NORTHWESTWARD (320/9 KT), AND A GENERAL NORTHWESTWARD TO
WEST-NORTHWESTWARD MOTION IS FORECAST THROUGH 72 HR AS THE CYCLONE
IS STEERED BY A MID-LEVEL RIDGE OVER THE SOUTHERN UNITED STATES. AS
PREVIOUSLY STATED, THE TRACK FORECAST IS MORE UNCERTAIN THAN USUAL
BY 72 H AS TRUDY ARRIVES INTO A REGION WITH WEAK STEERING FLOW
BETWEEN THE RETREATING MID-LEVEL RIDGE AND AN APPROACHING TROUGH
OVER THE WESTERN UNITED STATES. THE DETERMINISTIC GLOBAL MODELS ARE
SIGNIFICANTLY SLOWER THAN THE HFIP CORRECTED CONSENSUS AID (HCCA),
GOOGLE DEEPMIND (GDMI), THE EUROPEAN CENTRE'S AIFS, AND THE AI-GFS.
THE NEW TRACK FORECAST CLOSELY FOLLOWS HCCA AND GDMI, WHICH HAVE
BEEN THE BEST-PERFORMING TRACK FORECAST AIDS THIS SEASON. COMPARED
TO THE PREVIOUS FORECAST, THE NEW NHC TRACK IS FASTER AND NUDGED
EAST OF THE PREVIOUS ONE, ESPECIALLY AT AND BEYOND 72 H. THIS BRINGS
TRUDY INLAND OVER WESTERN MEXICO LATER THIS WEEKEND WITH THE CYCLONE
EMERGING IN THE SOUTHERN GULF OF CALIFORNIA BY EARLY NEXT WEEK. IF
TRUDY TRACKS FARTHER INLAND OVER WESTERN MEXICO, THE CIRCULATION MAY
NOT SURVIVE AND RAPIDLY DISSIPATE INLAND. REGARDLESS OF THE EXACT
TRACK, TRUDY IS EXPECTED TO APPROACH THE COAST OF MEXICO AS A MAJOR
HURRICANE LATER THIS WEEK.
THE CENTER OF TRUDY APPEARS NESTLED UNDER A SMALL AND INCIPIENT
CENTRAL DENSE OVERCAST. WHILE A SHORT-TERM TREND ON SATELLITE, THIS
CHANGE IN ORGANIZATION OF A SMALL INNER CORE COMBINED WITH EXTREMELY
FAVORABLE ENVIRONMENTAL CONDITIONS SUPPORTS AN AGGRESSIVE INTENSITY
FORECAST THAT EXPLICITLY DEPICTS RAPID INTENSIFICATION AND MAKES
TRUDY A HURRICANE WITHIN 24 H. THIS IS ALSO SUPPORTED BY SOME OF THE
STATISTICAL RAPID INTENSITY GUIDANCE. THE NEW INTENSITY FORECAST IS
ADJUSTED SLIGHTLY ABOVE THE PREVIOUS ONE, IN AGREEMENT WITH GDMI AND
HCCA, OUR BEST PERFORMING INTENSITY GUIDANCE THIS SEASON. GDMI,
HCCA, AND THE NHC FORECAST ARE ON THE HIGHER END OF THE INTENSITY
GUIDANCE, THOUGH THIS APPEARS THE MOST LIKELY SOLUTION BASED ON THE
OFFICIAL TRACK FORECAST. THE HURRICANE REGIONAL MODELS, WHICH CAN
BE MORE SKILLFUL FOR INTENSITY THAN THE COARSER GLOBAL MODELS, USE
THE GFS FOR INITIALIZATION AND BOUNDARY CONDITIONS. FOR THIS CYCLE,
THE GFS TRACK IS UNREALISTIC, AND THE HURRICANE REGIONAL MODELS
APPEAR TO SUCCUMB TO THIS AND PROVIDE AN OUTLIER (WEAKER) OUTCOME.
AT 120 H, THE INTENSITY FORECAST SHOWS TRUDY REMAINING A HURRICANE
AFTER EXITING MEXICO, THOUGH THIS INTENSITY WILL BE HIGHLY
SENSITIVE TO THE AMOUNT OF LAND INTERACTION.
KEY MESSAGES:
1. TRUDY IS FORECAST TO BE A MAJOR HURRICANE AS IT APPROACHES THE
COAST OF SOUTHWESTERN AND WEST-CENTRAL MEXICO LATE THIS WEEK AND
INTO THE WEEKEND. THERE IS AN INCREASING RISK OF WIND, RAIN, AND
STORM SURGE IMPACTS, AND WATCHES COULD BE REQUIRED FOR A PORTION OF
THESE AREAS ON WEDNESDAY.
FORECAST POSITIONS AND MAX WINDS
INIT 14/0300Z 11.2N 97.0W 40 KT 45 MPH
12H 14/1200Z 11.8N 98.6W 50 KT 60 MPH
24H 15/0000Z 12.6N 100.0W 65 KT 75 MPH
36H 15/1200Z 13.5N 100.9W 80 KT 90 MPH
48H 16/0000Z 14.3N 101.5W 100 KT 115 MPH
60H 16/1200Z 15.2N 101.9W 110 KT 125 MPH
72H 17/0000Z 16.3N 102.5W 115 KT 130 MPH
96H 18/0000Z 19.0N 104.4W 115 KT 130 MPH
120H 19/0000Z 21.0N 106.0W 75 KT 85 MPH
FORECASTER MAHONEY
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