Weather warnings/advisories

Thunder

  • Thunderstorm advisory
    • The Japan Metrological Agency issues it when it forecasts that disaster due to lightning strikes is expected to occur.
    • In addition to lightning strikes, alerts may be added to warn of the possibility of damage to people and buildings due to violent weather phenomena occurring often under developing cumulonimbus clouds, such as sudden heavy rain, gusty winds such as tornadoes, and hail.
    • A thunderstorm advisory also includes an alert for sudden and strong rain.

Heavy Rain

  • Heavy rain advisory
    • The Japan Metrological Agency issues it when it forecasts that flood disaster or sediment disaster due to heavy rain are expected to occur. When sediment disaster etc. are expected to occur, the announcement holds despite of no rain.
    • *The website of The Japan Meteorological Agency “List of the standard of issuing warning/advisory”
    • (http://www.jma.go.jp/jma/kishou/know/kijun/hiroshima.html)外部サイト別ウィンドウで開く
  • Heavy rain warning
    • The Japan Metrological Agency issues it when it forecasts that major flood disaster or sediment disaster due to heavy rain are expected to occur. When major sediment disaster etc. are expected to occur, the announcement holds despite of no rain.
    • *The website of The Japan Meteorological Agency “List of the standard of issuing warning/advisory”
    • (http://www.jma.go.jp/jma/kishou/know/kijun/hiroshima.html)外部サイト別ウィンドウで開く

Flood

  • Flood advisory
    • The Japan Metrological Agency issues it when a flood disaster is forecast to occur due to swelling of a downstream river caused by heavy rain or melting snow in the upper reaches.
    • Flood disasters include swelling of rivers, damage of levees, and flooding damage caused by these events.
    • *The website of The Japan Meteorological Agency “List of the standard of issuing warning/advisory”
    • (http://www.jma.go.jp/jma/kishou/know/kijun/hiroshima.html)外部サイト別ウィンドウで開く
  • Flood warning
    • The Japan Metrological Agency issues it when a serious flood disaster is forecast to occur due to swelling or overflowing of a downstream river caused by heavy rain or melting snow in the upper reaches.
    • Major flood disasters include swelling and overflowing of rivers, damage and breaches of levees, and serious flood damage caused by these events.
    • *The website of The Japan Meteorological Agency “List of the standard of issuing warning/advisory”
    • (http://www.jma.go.jp/jma/kishou/know/kijun/hiroshima.html)外部サイト別ウィンドウで開く

Storm surge

  • Storm surge advisory
    • The Japan Metrological Agency issues it when it forecasts that a disaster due to an extreme rise in sea level caused by typhoon, low-pressure system, or similar is expected to occur.
    • *The website of The Japan Meteorological Agency “List of the standard of issuing warning/advisory”
    • (http://www.jma.go.jp/jma/kishou/know/kijun/hiroshima.html)外部サイト別ウィンドウで開く
  • Storm surge warning

Tsunami

  • Tsunami advisory
    • Tsunami advisory is issued when there is a risk of disaster due to a tsunami with a maximum forecast height of between 0.2 meter and 1 meter.
    • Persons in the sea must immediately get out of the water and distance themselves from the coastline. Do not go swimming or rock fishing as it is dangerous. Do not enter the sea or go near the coastline until the advisory is lifted.
  • Tsunami warning
    • Tsunami warning is issued when there is a risk of disaster due to a tsunami with a maximum forecast height of between 1 meter and 3 meters.
    • Persons in coastal areas and along rivers must immediately evacuate to higher ground, buildings designated as tsunami evacuation faciities, or other safe locations. Do not leave your safe location until the warning is lifted.
  • Great tsunami warning
    • Great tsunami warning is issued when there is a risk of disaster due to a tsunami with a maximum forecast height of over 3 meters.
    • Persons in coastal areas and along rivers must immediately evacuate to higher ground, buildings designated as tsunami evacuation faciities, or other safe locations.
    • Do not leave your safe location until the warning is lifted.

Emergency warning

  • Emergency warning
    • Emergency warning is issued and maximum vigilance is called for when torrential rain etc. exceeding the criteria to issue warnings are expected, and major disaster risk has been extremely increasing.
    • The Japan Metrological Agency issues 6 kinds of emergency warnings.
    • In addition, major tsunami warning is placed in emergency warnings.
  • Heavy rain emergency warning
    • Heavy rain emergency warning is issued when a typhoon or localized torrential rain is expected to cause heavy rainfall that will reach a once-in-several-decades level.
    • Items that require special attention will be clearly indicated in the title and announced as ”Heavy Rain Emergency Warning (Sediment Disaster),” ”Heavy Rain Emergency Warning (Flooding Damage),”
    • or ”Heavy Rain Emergency Warning (Sediment Disaster, Flooding Damage).
  • Heavy snow emergency warning
    • Heavy snow emergency warning is issued when heavy snow causing the amount of snowfall once in every several decades is expected.
  • Storm emergency warning
    • Storm emergency warning is issued when stormy weather is expected due to as a strong typhoon or an extratropical cyclone as it occurs once in every several decades.
  • Blizzard emergency warning
    • Blizzard emergency warning is issued when stormy weather with snow is expected due to as a strong typhoon or an extratropical cyclone as it occurs once in every several decades.
    • Vigilance is called for when “major disaster due to obstruction to visibility (shutting out the view) with snow etc.”
    • in addition to “major disaster due to storm” are highly expected.
  • Storm surge emergency warning
    • Storm surge emergency warning is issued when storm surge is expected due to as a strong typhoon or an extratropical cyclone as it occurs once in every several decades.
  • High waves emergency warning
    • High wave emergency warning is issued when high wave is expected due to as a strong typhoon or an extratropical cyclone as it occurs once in every several decades.
    • This “high wave” is totally different from “tsunami” due to earthquake.

Information on record-breaking heavy rain in a short period of time

  • Information on record-breaking heavy rain in a short period of time
    • The Japan Meteorological Agency issues it when a short period of heavy rainfall occurring only once every few years is observed
    • (using ground-based rain gauges) or analyzed (using a combination of weather radar and ground-based rain gauges: analytical rainfall).
    • This information is announced when the rainfall criterion is met and ”extremely dangerous” (light purple) of the Kikikuru (risk distribution)
    • scale appears during the announcement of a heavy rainfall warning in order to inform the public that the current rainfall is a rarely observed amount that may lead to sediment disasters,
    • flooding damages, or flooding of small and medium-sized rivers in the area. Accordingly, the name of the observation point, city, town, etc. where the heavy rain was observed is clearly indicated.
    • In Hiroshima city, it was issued when sediment disaster occurred on August 20, 2014.
    • *The website of The Japan Meteorological Agency “Information on record-breaking heavy rain in a short period of time”
    • http://www.jma.go.jp/jma/kishou/know/bosai/kirokuame.html外部サイト別ウィンドウで開く
    • *the website of the Japan Meteorological Agency「kikikuru(Warning risk distribution)」
    • https://www.jma.go.jp/jma/kishou/know/bosai/riskmap.html外部サイト別ウィンドウで開く

Tornado warning

  • Tornado warning
    • The Japan Meteorological Agency (JMA) etc. issue it for the region (1 prefecture in general) which JMA etc.
    • are in charge of, as information to pay attention to violent storm with very strong winds such as tornados and downbursts under cumulonimbus clouds (“tornados etc.” below) and additional information on thunderstorm advisory.
    • It is valid for about 1 hour after the announcement.

Sediment disaster warning services

  • Sediment disaster warning services
    • After the announcement of a heavy rain warning (sediment disaster), the prefectural government and the Japan Meteorological Agency jointly announce sediment disaster warning services
    • to specify the affected municipalities and call for caution in order to assist the mayors of the municipalities in making decisions on evacuation orders and voluntary evacuation of
    • residents when a life-threatening sediment disaster could occur at any time.
  • Index of rainfall in the soil
    • Index of rainfall in the soil is an indicator for understanding the increase in the risk of sediments due to rainfall.
    • Sediment disasters (landslides and debris flows) that occur with heavy rains are closely related not only to the current rain,
    • but also to the amount of water in the soil caused by rain that has fallen previously. The index of rainfall in the soil quantifies the amount of water accumulated in the soil from rainfall by using a tank model.
    • This index is used as a criterion for heavy rain warnings (sediment disasters) and sediment disaster warning services announced by local weather stations.
  • Information on risk of landslide disasters
    • In Hiroshima Pref, it provides the detailed information regarding a degree of risk of occurring sediment disaster in regions in 5km mesh supplementing the contents of sediment disaster alerting information.
    • The city will issue evacuation instructions for people in the landslide warning area according to the risk level of the indicated area.

Flood forecast on designated rivers

  • Flood forecast on designated rivers
    • The Japan Meteorological Agency jointly with Ministry of Land, Infrastructure, Transport and Tourism or prefectural agencies gives forecasts of floods with the water level or the volume of flowing water
    • regarding the designated rivers for reference of determination of prevention activities against flood or raised water level in the river, or act of resident’s evacuation.
    • In Hiroshima city, the following rivers are designated in advance.
    • The river forecasting floods) The section managed by the nation of upstream of Ootagawa River, downstream of Ootagawa River, Misasagawa River and Nenotanigawa River
  • Overflow advisory information
    • Overflow advisory information is issued when the water level of water level observatory to be the criteria reaches an overflow advisory water level, and its water level is also expected to rise in the river forecasting floods.
    • We have reached the stage of demanding attention to the occurrence of overflow to residents.
  • Overflow alerting information
    • Overflow alerting information is issued when the water level of water level observatory to be the criteria is expected to reach an overflow danger water level after a certain time,
    • or reaches the water level of determing the evacuation, and its water level is also expected to rise in the river forecasting floods.
    • This is the stage to ask the elderly and other persons requiring special care to start evacuating.
  • Overflow danger information
    • Overflow danger information is issued when the water level of water level observatory to be criteria reaches an overflow danger water level in the river forecasting floods.
    • As overflow may occur at any moment, we have reached the stage of demanding response to the occurrence of overflow such as evacuation etc. to residents.
  • Information on occurrence of overflow
    • Information on occurrence of overflow is issued when overflow occurs in the river forecasting floods. We have reached the stage of demanding warning to flood due to overflow to residents.

Information on reaching water level

  • Information on reaching water level
    • When the water level reaches a certain level in a river that has been designated as a river requiring notification and dissemination of information regarding the reaching of flood danger water level,
    • the river administrator (Ministry of Land, Infrastructure, Transport and Tourism or the prefectural government) will announce the information about the reaching of such level.
    • The following rivers in Hiroshima have already been designated as requiring notification. River publicizing a water level
      • The river managed by the nation : Kyuootagawa River, Motoyasugawa River, Furukawa River
      • The river managed by the prefecture : Yahatagawa River, Yasukawa River, Misasagawa River, Nenotanigawa River, Minochigawa River, Senogawa River, Fuchuookawa River, Suzuharigawa River, Okanoshitagawa River, Nabaragawa River
  • Overflow advisory information
    • Overflow advisory information is issued when the water level of water level observatory to be criteria reaches an overflow advisory water level in the river publicizing a water level.
  • Overflow alerting information
    • Overflow alerting information is issued when the water level of water level observatory to be criteria reaches a level of determing the evacuation in the river publicizing a water level.
  • Overflow danger information
    • Overflow danger information is issued when the water level of water level observatory to be criteria reaches an overflow danger water level in the river publicizing a water level.

Typhoon information

  • Typhoon information
    • Typhoon information is released by the Japan Meteorological Agency when a typhoon or a tropical cyclone that is expected to develop into a typhoon within 24 hours (”developing tropical cyclone” below) occurs, and includes the actual and forecasted position and strength of the typhoon.
    • More detailed information is provided with more frequent updates as the typhoon approaches Japan.

Earthquake information

  • Seismic intensity
    • The seismic intensity is a scale to measure the intensity of earthquakes.
    • The Japan Meteorological Agency seismic intensity (shindo) scale gives a total of 10 levels of
    • earthquake: “shindo 0”, “shindo 1”, “shindo 2”, “shindo 3”, “shindo 4”, “shindo 5-lower”, “shindo 5-upper”, “shindo 6-lower”, “shindo 6-upper”, “shindo 7”.
    • You can confirm effects on people, indoor situations and outdoor situations in each seismic intensity (shindo) scale on the website of The Japan Meteorological Agency.
    • *The website of The Japan Meteorological Agency “Seismic intensity (shindo) scale explanation table of The Japan Meteorological Agency”
    • (http://www.jma.go.jp/jma/kishou/know/shindo/kaisetsu.html)外部サイト別ウィンドウで開く

Observed information

Information on amount of rainfall

  • Rainfall in 10 minutes
    • It is rainfall in the most recent 10 minutes.
  • Rainfall in 60 minutes
    • It is rainfall in the most recent 60 minutes (1 hour). You can confirm the strength of rain and the way rain falls on the website of The Japan Meteorological Agency.
    • *The website of The Japan Meteorological Agency “The strength of rain and the way rain falls”
    • http://www.jma.go.jp/jma/kishou/know/yougo_hp/amehyo.html外部サイト別ウィンドウで開く
  • Effective rainfall
    • Effective rainfall is the standard rainfall calculating the effect of rainfall in the past by decreasing it over time. This city’s system uses the 72 hours half-value period.
  • Cumulative rainfall
    • “Cumulative rainfall” is a total amount of rainfall from starting raining to that time. Cumulative rainfall will be reset after no rain continues for a certain period of time. When a rainfall is detected after that, it is regarded as new rain (starting raining).

State of rain clouds

  • High-resolution Precipitation Nowcasts
    • High-resolution Precipitation Nowcasts provide short-range precipitation intensity predictions with a spatial resolution of 250 m. They are derived from weather radar data by The Japan Meteorological Agency.

Information about significant heavy rain

  • Information about significant heavy rain
    • Information on significant heavy rainfall uses the keywords ”linear precipitation zone” to describe the condition where very heavy rain continues to fall in the same place due to a linear precipitation zone, while the risk of disaster due to heavy rain is rapidly increasing.

Standard water level

  • Stand-by water level for flood fighting corps
    • It is a water level set to flood prevention warning rivers and it is also the standard water level which flood prevention teams standby against floods and storm surges and prepare for flood prevention activities.
    • It corresponds to a water level of notify, written in the provisions of Article 12 of the Flood Prevention Act. The flood control warning rivers of this city are as follows.
    • The flood control warning river)
      • The river managed by the nation: Ootagawa River, Misasagawa River, Nenotanigawa River, Kyuootagawa River, Motoyasugawa River, Tenmagawa River
      • The river managed by the prefecture : Yahatagawa River, Yasukawa River, Misasagawa River, Nenotanigawa River, Minochigawa River, Senogawa River, Enkougawa River, Kyoubashigawa River
  • Flood watch water level
    • It is a water level to be cautious about disaster occurrence due to floods and storm surges (warning water level given by the provisions of Article 12 of the Flood Prevention Act).
    • Also, it is the standard water level which flood prevention teams etc. dispatch in the flood prevention warning rivers.
    • It is essential that we pay fully attention to rise of a water level after reaching.
  • Water Level Basis for Decision to Evacuate
    • This is the water level at which the mayor of the municipality will make a decision to issue evacuation instructions for the elderly and other persons requiring special care, and begin alerting residents to information about flooding.
    • After it has been reached, sufficient caution is required regarding rising water levels.
  • Flood danger water level
    • This is a water level that requires special warning about the occurrence of disasters due to flooding (Emergency warning water level set forth in Article 13 of the Flood Control Act),
    • and it serves as a guide for the mayor of the municipality to issue evacuation instructions, etc., and as a reference for residents to make evacuation decisions.
    • After it has been reached, extreme caution is required regarding rising water levels.
  • Overflow start level
    • This is the water level at each point where overflow starts, such as the top of an embankment (or the height of the ground behind the embankment), in a series of areas of a river
    • that are considered to have a high possibility of overflowing or flooding, converted into the water level at the water level observatory that serves the area.

Tide level information

  • Warning tide level
    • It is the standard tide level which flood prevention teams standby against storm surges and prepare for flood prevention activities. It has been set T.P.2.1m in Hiroshima port designated for Hiroshima city.
  • Tide Level Alert
    • It is a tide level to be cautious about disaster occurrence due to storm surges while it is the standard tide level which flood prevention teams etc. dispatch. It has been set T.P.2.5m in Hiroshima port designated for Hiroshima city.
  • Astronomical tide
    • Such as high tide, low tide and flood tide, neap tide, a change in tide level caused by tidal force of moon and sun is called “astronomical tide” and its tide level is called “astronomical tide level”.
    • If there is an observation data with good accuracy about a certain point in long term, astronomical tide level of that point can be predicted in a high accuracy.

Evacuation information

Alert (call for voluntary evacuation)

  • Alert (call for voluntary evacuation)
    • Disaster prevention information (such as weather information) is transmitted to the entire city or areas where required when a disaster is deemed likely to occur such as when a heavy
    • rain warning or similar is issued to alert the resident and, depending on the conditions, the city will check dangers in the area and encourage residents to evacuate (voluntary evacuation)
    • if judged to be dangerous.

[Alert Level 3] Evacuation of the elderly, etc.

  • [Alert Level 3] Evacuation of the elderly, etc.
    • The city will issue this instruction when there is a possibility of a disaster occurring.
    • This city generally issues it for residents living in dangerous areas such as sediment disaster special alert and flood-assumed areas in elementary school districts.
    • The actions required of residents are as follows.
      • Persons requiring time to evacuate, such as the elderly, the disabled, and those with small children, and persons who assist them must immediately start evacuation activities at designated emergency evacuation areas set up by the city, or at the homes of relatives or friends in safe locations.
      • It is desirable for people other than those indicated above to suspend their normal activities, such as refraining from going outside, to work and similar activities, and to prepare for evacuation or evacuate voluntarily if necessary.

[Alert Level 4] Evacuation order

  • [Alert Level 4] Evacuation order
    • The city will issue this order when there is a increased possibility of a disaster.
    • This city generally issues it for residents living in dangerous areas such as sediment disaster special alert and flood-assumed areas in elementary school district.
    • The actions required of residents are as follows.
      • Evacuate immediately from at-risk areas.
      • In the event of a flood or storm surge, if it can be confirmed through hazard maps, etc., that it is possible to ensure personal safety indoors on upper floors, etc., it is possible to ensure safety indoors at one’s own discretion. However, for landslides and tsunamis, evacuation is required.

[Alert Level 5] Ensure emergency safety

  • [Alert Level 5] Ensure emergency safety
    • It is issued by the city in situations where a disaster has occurred or is imminent, or where it is actually considered dangerous to evacuate in order to ensure personal safety.
    • The actions required of residents are as follows.
      • Due to the danger to life, take action to ensure safety immediately.
      • If evacuating to a designated emergency evacuation area or similar location is dangerous, you should immediately ensure your own safety by moving to a higher location, or a place away from mountains or cliffs that you can judge to be relatively safe.

Dangerous areas

Flood-assumed area

  • Flood-assumed area
    • Regarding the river forecasting floods and the river designated the river publicizing a water level,
    • Ministry of Land, Infrastructure, Transport and Tourism and prefectures designates the areas assumed to flood when the said rivers
    • overflow due to assumed maximum rainfall as a flood-assumed area in order to reduce flood damages through securing smooth and prompt evacuation in case of flood or preventing floods.
    • Also, they publicize designated areas and assumed water depth and duration time of flooding in case of flood as a flood-assumed area chart.
    • You find a list of target rivers and setting of rainfall on this city’s website.
    • *This city’s website “Flood hazard map in Hiroshima city”
    • (https://www.city.hiroshima.lg.jp/site/saigaiinfo/17890.html)外部サイト別ウィンドウで開く

Possible sediment disaster areas

  • landslide disaster warning area
    • These areas are designated by Hiroshima Prefecture in accordance with the Landslide Disaster Prevention Law, which was enacted in response to the landslide that occurred in Hiroshima City and other areas on June 29, 1999.
    • These areas are deemed to pose a risk to the lives or bodies of residents in the event of a collapse of steep slopes.
  • Special alert area for soil and sand disaster
    • These areas are designated by Hiroshima Prefecture based on the Landslide Disaster Prevention Law, and are recognized as areas where the collapse of steep slopes, etc.
    • could cause damage to buildings and significant harm to the lives or bodies of residents, etc.
    • Permission is required for certain development activities, and structural regulations for buildings are enforced.

Estimate inland waters flooding area

  • Estimate inland waters flooding area
    • The City of Hiroshima has announced the areas that are expected to be flooded by inland waters in relation to the expected maximum rainfall based on the Flood Prevention Law or the maximum rainfall in the past.
    • *Hiroshima City website ”Flooding (by Inland Waters) Hazard Map”.
    • https://www.city.hiroshima.lg.jp/site/gesuido/2779.html外部サイト別ウィンドウで開く

Estimated storm surge and flood area

  • Estimated storm surge and flood area
    • Hiroshima Prefecture has published an estimated storm surge and flood area map showing the estimated areas and depths of flooding in the event of a typhoon storm surge.
    • There are currently three possible cases of a maximum scale case, a 30-year probability case, and an Isewan Typhoon scale case.
    • The estimated storm surge and flood area map can be viewed at the website of Hiroshima Prefecture.
    • * Hiroshima Prefecture website ”Portal Site Hiroshima for disaster of storm surge and tsunami”
    • https://www.takashio.pref.hiroshima.lg.jp/portal/top.aspx外部サイト別ウィンドウで開く

Tsunami disaster special alert area

  • Tsunami disaster special alert area
    • Hiroshima Prefecture designates areas where evacuation systems need to be maintained to prevent tsunami disasters as tsunami disaster special alert areas so that residents of areas where there is a risk of lost lives or injuries in the event of a maximum class tsunami are ”notified”
    • regarding tsunami flood estimates and reference water levels, and so that residents can ”escape” from a tsunami smoothly and quickly in times of emergency.
    • The estimated tsunami disaster special alert area map can be viewed on the website of Hiroshima Prefecture.
    • *Hiroshima Prefecture website ”Portal Site Hiroshima for disaster of storm surge and tsunami”
    • https://www.takashio.pref.hiroshima.lg.jp/portal/top.aspx外部サイト別ウィンドウで開く

Evacuation area etc.

Designated emergency evacuation area

  • Designated emergency evacuation area
    • Those are facility and place designated by this city in advance in classification of disaster as an evacuation area in order to protect people’s life from imminent danger of disaster.
    • These are the evacuation sites will be established when evacuation instructions are issued.
    • City-owned facilities such as school or community center are mainly designated.
    • Classification of disaster) sediment disaster, flood, storm surge, earthquake, tsunami, big fire

Designated shelter

  • Designated shelter
    • These are facilities designated by Hiroshima City in advance as a location for residents to live temporarily for a certain period if they have become homeless due to disaster.
    • Some facilities also serve as designated emergency evacuation areas.
    • Schools, sports centers and similar facilities are mainly designated.

Others

Civil protection services

  • Civil protection services
    • We will inform you of any information on civil protection announced by the national government (information on ballistic missiles, guerilla attacks, air strikes, large-scale acts of terrorism, and other relevant information on civil protection).

Headquarter for disaster control

  • Headquarter for disaster control
    • It is established in order to respond to a possible large-scale disaster. A mayor and a ward mayor play a role as a chief of the headquarter in the city and in the ward respectively.