This is storm FRANCENE:FRANCESCA that was active in 1971 in the E. Pacific region with maximum winds of 185 km/h.

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Max Wind: 185 km/h. Min Pressure: hPa.

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Storm Detail 1971

FRANCENE:FRANCESCA (1971)

Name: storm FRANCENE:FRANCESCA
Start: 1971-07-18
End: 1971-07-23
Location: E. Pacific

Storm Code: 1971199N11254 | Region: E. Pacific
Active from 18/07/1971 to 23/07/1971 (6 days)

185 km/h

As measured · 1-min avg

Peak wind · 1-min (JTWC)

Converted ≈ 163 km/h · 10-min avg

Level 14

185 km/h

As measured · 10-min avg

Peak wind · 10-min (WMO)

Converted ≈ 163 km/h · 10-min avg

Level 14

991 hPa

Min Pressure

2,704 km

Distance

Forecast Agencies

Beaufort scale: all winds converted to the 10-min avg standard (WMO). Each agency's original value is shown alongside.

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Weather Agencies (4 sources)

WMO (International) 185 km/h

JTWC 185 km/h

DS824 185 km/h

TD9636 N/A

Storm Lifecycle Timeline

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Storm Structure

FRANCENE:FRANCESCA

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FRANCENE:FRANCESCA

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Track List (0 points)

#	Time (GMT+7)	Position	Wind (km/h)	Pressure	Level

Wind Intensity Chart

JTWC DS824 TD9636

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Quick Stats

185 km/h

Max Wind

991 hPa

Min Pressure

132h

Activity Duration

Forecast Agencies

Agency Data Comparison

WMO (International) 1-min avg

163 km/h Max Wind Orig.: 185 km/h

991 hPa Min Pressure

23 Measurements

JTWC 1-min avg

163 km/h Max Wind Orig.: 185 km/h

991 hPa Min Pressure

45 Measurements

DS824 1-min avg

163 km/h Max Wind Orig.: 185 km/h

991 hPa Min Pressure

45 Measurements

TD9636

N/A Max Wind

N/A Min Pressure

45 Measurements

Agency	Max Intensity		Trajectory		Energy		highest_classification
Agency	Max Wind (km/h)	Min Pressure (hPa)	Number of points	Distance (km)	ACE (10⁴ (km/h)²)	PDI (10⁶ (km/h)³)	highest_classification
WMO (International)	163 Orig.: 185	991	23	2,688	25.59	36.91	Level 14 - Violent Storm
JTWC	163 Orig.: 185	991	45	2,704	25.59	36.91	Level 14 - Violent Storm
DS824	163 Orig.: 185	991	45	2,704	25.59	36.91	Level 14 - Violent Storm
TD9636 (coordinates_only)	~	~	45	2,697	~	~	Undefined

Indices Legend

Max Wind (kt/km/h): Maximum wind speed by agency

Min Pressure: Lowest central pressure

Number of points: Number of observation points in track

Distance: Total track distance traveled

ACE: Accumulated Cyclone Energy

PDI: Power Dissipation Index

Advanced Meteorological Indices by Agency Automatically calculated from raw data

WMO (International) RI

Energy
ACE (10⁴ (km/h)²)	25.59	High
PDI (10⁶ (km/h)³)	36.91
Intensification / Weakening
Max Wind Gain/Step	+65 km/h
Max Wind Gain/24h	+130 km/h	RI
Max Wind Loss/Step	-74 km/h
Pressure Variation
Max Pressure Drop/24h	-10 hPa
Movement & Duration
Avg Movement Speed	20.4 km/h
Tracking Time	132h (5.5 days)
Time as TD+ (≥34kt)	114h (4.8d)
Time as Storm+ (≥64kt)	30h (1.3d)
Peak Intensity & Range
Peak Intensity	02:00 20/07/1971 14.9°N, -113.3°E
Latitude	11.3°N – 16.9°N (5.6°)
Longitude	-129°E – -105.7°E (23.3°)

JTWC RI

Energy
ACE (10⁴ (km/h)²)	25.59	High
PDI (10⁶ (km/h)³)	36.91
Intensification / Weakening
Max Wind Gain/Step	+33 km/h
Max Wind Gain/24h	+130 km/h	RI
Max Wind Loss/Step	-37 km/h
Pressure Variation
Max Pressure Drop/24h	-10 hPa
Movement & Duration
Avg Movement Speed	20.5 km/h
Tracking Time	132h (5.5 days)
Time as TD+ (≥34kt)	114h (4.8d)
Time as Storm+ (≥64kt)	30h (1.3d)
Peak Intensity & Range
Peak Intensity	02:00 20/07/1971 14.9°N, -113.3°E
Latitude	11.3°N – 16.9°N (5.6°)
Longitude	-129°E – -105.7°E (23.3°)

DS824 RI

Energy
ACE (10⁴ (km/h)²)	25.59	High
PDI (10⁶ (km/h)³)	36.91
Intensification / Weakening
Max Wind Gain/Step	+33 km/h
Max Wind Gain/24h	+130 km/h	RI
Max Wind Loss/Step	-37 km/h
Pressure Variation
Max Pressure Drop/24h	-10 hPa
Movement & Duration
Avg Movement Speed	20.5 km/h
Tracking Time	132h (5.5 days)
Time as TD+ (≥34kt)	114h (4.8d)
Time as Storm+ (≥64kt)	30h (1.3d)
Peak Intensity & Range
Peak Intensity	02:00 20/07/1971 14.9°N, -113.3°E
Latitude	11.3°N – 16.9°N (5.6°)
Longitude	-129°E – -105.7°E (23.3°)

TD9636

Movement & Duration
Avg Movement Speed	20.4 km/h
Tracking Time	132h (5.5 days)
Peak Intensity & Range
Latitude	11.3°N – 16.9°N (5.6°)
Longitude	-129°E – -105.7°E (23.3°)

Advanced Indices Legend

ACE: Accumulated Cyclone Energy - measures total storm activity

PDI: Power Dissipation Index - measures potential destructiveness

RI: Rapid Intensification - when wind increases >=30 kt/24h or pressure drops >=30 hPa/24h

Countries with Direct Landfall

Storm did not make landfall

Index	Meaning	Formula / Condition	Classification
ACE Accumulated Cyclone Energy	Accumulated Cyclone Energy. Measures the total energy generated by the storm during its lifetime. Only counts reports with wind ≥ 35 kt (TS level or higher).	`ACE = Σ(V_max²) / 10&sup4;` Unit: 10⁴ kt²	< 2: Low 2-6: Medium 6-15: High ≥ 15: Very High
PDI Power Dissipation Index	Power Dissipation Index. More sensitive than ACE to extremely strong storms due to using cubic power. Reflects potential destructive power.	`PDI = Σ(V_max&sup³;) / 10&sup6;` Unit: 10⁶ kt³	Higher value = greater cumulative destructive power
RI Rapid Intensification	Rapid Intensification - storm strengthens suddenly in a short time. Very dangerous as it is difficult to forecast and causes surprise for prevention efforts.	Wind increase ≥ 30 kt/24h or Pressure drop ≥ 30 hPa/24h	Has RI or Fast increase (≥20kt)
Max wind gain/step	Maximum wind increase between 2 consecutive reports (usually 6 hours apart). Shows the fastest local intensification rate.	`max(V_i+1 - V_i)` Unit: kt (km/h)	Positive value = storm strengthening
Max wind gain/24h	Maximum wind increase in a 24-hour window. Main criterion for determining Rapid Intensification (RI).	`max(V_t+24h - V_t)` RI if ≥ 30 kt/24h	≥ 30kt: RI ≥ 20kt: Fast
Max wind loss/step	Maximum wind weakening between 2 consecutive reports. Shows at which stage the storm weakened fastest.	`max(V_i - V_i+1)` Unit: kt (km/h)	Positive value = storm weakening
Max pressure drop/step	Maximum pressure drop between 2 consecutive reports. Pressure decrease = storm center strengthening. Reflects local deepening rate.	`max(P_i - P_i+1)` Unit: hPa	Higher value = faster strengthening
Max pressure drop/24h	Maximum pressure drop in a 24-hour window. Important index for evaluating explosive deepening / explosive intensification.	`max(P_t - P_t+24h)` Explosive if ≥ 30 hPa	≥ 30hPa: RI ≥ 20hPa: Strong
Max pressure rise/step	Maximum pressure rise between 2 consecutive reports. Pressure increase = storm weakening. Large value indicates rapid weakening (due to terrain interaction, landfall, etc.).	`max(P_i+1 - P_i)` Unit: hPa	Higher value = faster weakening
Average moving speed	Average moving speed of the storm center during the entire monitoring period by that agency.	`V_avg = S_total / T_total` Unit: kt (km/h)	Slow-moving storms (<15 km/h) usually cause prolonged heavy rain
Monitoring duration	Total time from first report to last report of that agency.	`T = t_end - t_start` Unit: hours (days)	Different agencies may monitor for different durations
TS+ Duration	Total hours with average wind ≥ 34 kt (Tropical Storm level or higher). Reflects how long the storm maintained significant intensity.	Average wind ≥ 34 kt	Longer storm = greater total damage
TY+ Duration	Total hours with average wind ≥ 64 kt (Typhoon level or higher). Storms maintaining this level longer have much greater destructive power.	Average wind ≥ 64 kt	Longer time at Typhoon level = more dangerous
Peak Intensity	Time and location (lat, lon) when the storm reached maximum wind according to each agency. Helps identify where the storm was strongest.	V_max = max(V_i)	Peak location helps assess danger for nearby areas
Latitude / Longitude	Spatial range of activity by latitude and longitude. Shows whether the storm affected area is wide or narrow.	min-max(lat), min-max(lon)	Large range = long trajectory, wide impact

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FRANCENE:FRANCESCA

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User Guide

FRANCENE:FRANCESCA (1971)

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Storm Structure

Comparison Storms 0

Weather Agencies (4 sources)

Storm Lifecycle Timeline

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Track List (0 points)

Wind Intensity Chart

Quick Stats

Agency Data Comparison

Indices Legend

Advanced Meteorological Indices by Agency Automatically calculated from raw data

Advanced Indices Legend

Countries with Direct Landfall

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FRANCENE:FRANCESCA

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