[Hokkaido: Rain Turning to Snow] Full-Scale Winter Arrives This Weekend (Weather Forecaster: Junko Miyake)

2026/11/05 15:01

Many parts of Hokkaido will see rain through Friday, but precipitation is expected to change over to snow across much of the region from Saturday onward.

As of noon today, only a few locations in Hokkaido are reporting rain. However, rain clouds associated with low-pressure systems and frontal boundaries to the south are expected to spread northward and move into Hokkaido.

Rain will begin mainly across southern Hokkaido later today, becoming widespread from late afternoon through the evening.

Around midnight, areas near Muroran may see pockets of heavy rain, indicated by yellow and orange rainfall intensity levels.

There is also a risk of thunderstorms, so please be cautious of lightning strikes and sudden gusty winds.

Rain is expected to continue over a wide area through early Friday morning.

By around midday Friday, rain will temporarily ease in many locations. However, another band of rain clouds will approach from the west during the evening.

This next round of rain is expected to be noticeably colder.

Let's take a look at the weather pattern behind this change.

By Friday night, a winter-type pressure pattern is expected to develop, with high pressure to the west and low pressure to the east. A low-pressure system near Hokkaido is forecast to deepen rapidly.

The pressure gradient will become very tight, leading to strengthening westerly winds across Hokkaido.

These strong westerly winds will usher in the strongest cold air mass of the autumn season so far.

The forecast for Friday night shows air colder than -6C at around 1,500 meters above sea level moving into western Hokkaido. This is generally cold enough to bring snowfall even to lowland areas.

This cold air mass is expected to advance farther south through Saturday and Sunday, eventually covering all of Hokkaido.

Looking at the forecast for precipitation and wind, rain will gradually change to snow from around midnight Saturday.

Many lowland areas across Hokkaido are expected to see snow, and some locations may experience accumulating snowfall by Saturday morning.

Strong westerly winds may also produce blizzard conditions and significantly reduced visibility.

Even if you have already switched to winter tires, this is still the early part of the snow season, and many drivers have not yet become accustomed to snowy road conditions.

Please use extra caution when driving on snow-covered roads.

Blowing snow may also cause poor visibility, so be especially careful when traveling.

Now, turning to the detailed forecast for each area:

Rain will begin spreading from southern Hokkaido later today and become widespread this evening.

Through early Friday morning, some locations could experience heavy rain and thunderstorms.

From Friday evening, rain will redevelop from western Hokkaido and gradually spread eastward.

Some areas are expected to change from rain to snow during the night.

At the same time, westerly winds will strengthen, making conditions feel increasingly cold.

Looking ahead to the extended forecast, cold air is expected to remain over the region for some time.

The season of frequent snow icons in the forecast has now arrived.

Please continue to exercise caution when driving on snowy roads.

In particular, heavy snow and blizzard conditions are possible this weekend, especially on Saturday and Sunday.

Strong winds may also disrupt transportation services, so be sure to stay updated with the latest weather information.

Today, Thursday the 5th, the peak of the rain has passed in the Kanto region; meanwhile, the area affected by rain will expand across Western and Northern Japan this afternoon.

2026/11/05 13:18

Today, Thursday the 5th, a weather front and an associated low-pressure system have brought active rain clouds to the Kanto region, particularly over the Izu Islands. On Niijima Island (part of Niijima Village, Tokyo), 60.5 mm of "very heavy" rain was recorded in the hour leading up to 3:09 a.m.

Currently, the most active rain clouds are concentrated over the ocean to the east. Meanwhile, active rain clouds have also begun to move into areas near Western Japan.



The low-pressure system along the front-currently located east of the Kanto region-is expected to move toward the waters off the Sanriku coast by tonight, suggesting that the peak of the rainfall in the Kanto region has passed. However, warm, moist air-flowing in from the periphery of a high-pressure system and circulating around Typhoon No. 31-is being drawn toward the low-pressure system and the front. Consequently, atmospheric conditions will remain highly unstable, especially around the Izu Islands. Through the early morning hours of tomorrow, Friday the 6th, please remain cautious of lightning strikes, severe gusts (such as those associated with tornadoes), and hail.



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A low-pressure system near the Tsushima Strait will move eastward, and the area of ??rain across western Japan will gradually shift toward the east this afternoon. Warm, moist air is expected to flow toward this low-pressure system, making the atmosphere highly unstable. Cumulonimbus clouds may develop locally, and in the Kyushu region in particular, some areas could experience heavy rain accompanied by thunderstorms.
In the Kinki region-including Wakayama Prefecture-areas along the Pacific coast may also see heavy rain accompanied by thunderstorms late tonight.
Rain is also expected to begin in the Hokuriku region late tonight.
There is a risk of lightning strikes and severe gusts, such as those associated with tornadoes. If you notice signs that a developed cumulonimbus cloud is approaching, please take steps to ensure your safety, such as moving indoors.





Additionally, a trough of low pressure is forming near northern Japan, and the area of ??rain will gradually expand there from this evening onward.
Today, Thursday the 5th, is likely to be a day where rain is expected across much of the country.
Please remember to bring your rain gear.

[Kanto-Koshin Region] Atmospheric instability expected through the early hours of tomorrow, the 6th; caution also advised regarding unseasonable heat.

2026/11/05 13:08

A weather front extends from south of Japan, passing near the Izu Islands and reaching east of the Kanto region. A low-pressure system has formed along this front near the Izu Islands and is moving toward the northeast. Warm, moist air-flowing in from the periphery of a high-pressure system far to the east of Japan and circulating around Typhoon No. 31-has moved toward this low-pressure system and the front.
As a result, atmospheric conditions across the Kanto-Koshin region have become highly unstable,
leading to the development of active rain clouds from last night through this morning.



Due to these conditions, Niijima (Tokyo) recorded a 6-hour rainfall total of 202.5 mm by dawn on the 5th-the highest ever recorded at that location.
Kozushima also recorded 168.0 mm, setting a new record for the month of November.



As of midday, the active rain clouds have moved away toward the ocean to the east;
however, atmospheric conditions across the Kanto-Koshin region will remain unstable until tomorrow morning.
Please continue to exercise caution regarding flooding in low-lying areas, as well as rising water levels or potential overflowing of rivers.

The projected 24-hour rainfall totals through tomorrow morning are as follows (in areas with the heaviest precipitation):
Northern Kanto region: 50 mm
Southern Kanto region: 80 mm
Izu Islands: 100 mm

Additionally, please remain cautious of lightning strikes and severe gusts-such as those associated with tornadoes-through the early morning of the 6th. If there are signs that a developed cumulonimbus cloud is approaching, please take steps to ensure your safety, such as moving indoors. There is also a risk of hail, so please take precautions to protect agricultural crops and facilities.

Tomorrow, the 6th, the weather in the Kanto-Koshin region is expected to gradually improve,
with sunshine likely throughout the day.
Temperatures will rise due to the sun; the high in Tokyo is forecast to reach 24C,
while Kofu is expected to reach 25C-a "summer day" (a day with a high of 25C or above).



With a significant temperature difference of around 10C between the day and the morning/evening hours,
please take care to ensure that these temperature fluctuations do not affect your health.

Heavy rainfall, primarily in Western Japan, due to Typhoon 30 and a weather front; first snowfall recorded in the northern Tohoku region as cold air moves southward (Weather Summary: October 25–31, 2026)

2026/11/05 11:27

# Summary of Weather Conditions for the Current Period (October 25 - October 31)
Average temperatures were near normal in Northern Japan and Okinawa. In Eastern and Western Japan, the influx of warm air from the south led to temperatures above the seasonal average; in Southern Kyushu, temperatures were significantly higher-more than 3C above the norm.

Precipitation was well below average in parts of Hokkaido, the Pacific side of the Tohoku region, Southern Kyushu, and Okinawa. Conversely, due to factors such as a stationary front near Honshu, Typhoon No. 30, and a pressure pattern characterized by high pressure to the west and low pressure to the east, precipitation was above or well above average across the Sea of ??Japan side of Tohoku, the Hokuriku region, and the area spanning from Kanto to Northern Kyushu. In the Chugoku region and Northern Kyushu, in particular, precipitation exceeded 400% of the seasonal average.

Sunshine duration was above average in Hokkaido, Southern Kyushu, and Okinawa-areas less affected by the aforementioned fronts and typhoons-while it was below average across the region from Tohoku to Northern Kyushu, where the impact was greater.

# Characteristics of Pressure Patterns
On the 25th, a front remained stationary across western and eastern Japan, while a low-pressure system along the front moved east-northeast, passing east of Japan. Typhoon No. 30 moved northeast across the East China Sea before transitioning into an extratropical cyclone. On the 26th, this system-having transitioned from Typhoon No. 30-moved eastward, accompanied by a front, from the area south of Kyushu toward the area south of Shikoku. On the 27th, a low-pressure system moved eastward near Sakhalin. The system that had originated from Typhoon No. 30 became ill-defined south of Honshu. Meanwhile, a low-pressure system along a front extending from south of Honshu to the east of Japan moved further east. On the 28th, a low-pressure system over the Sea of ??Okhotsk intensified rapidly while moving northeast. A "west-high, east-low" pressure pattern (typical of winter) prevailed around Japan. On the 29th, the region was covered by a high-pressure system centered to the east of Japan. On the 30th, this high-pressure system moved far to the east, leaving the area around Japan under a pressure trough. Typhoon No. 31... ...moving westward in the vicinity of the [Ogasawara] Islands. On the 31st, a pressure trough was present near Japan. A front, extending from a low-pressure system east of Japan, stretched from the waters east of the Kanto region to the area south of Japan. Low-pressure systems were also located east of Hokkaido and over the Sea of ??Okhotsk, both moving northeastward. Typhoon No. 31 was moving north-northwestward in the waters near the Ogasawara Islands.

# Precipitation
On the 25th, influenced by a front and Typhoon No. 30, rainfall intensified, particularly along the Pacific side of Western Japan. Extremely heavy rain was recorded in areas such as Kochi and Wakayama Prefectures. On the 26th, due to a front and a low-pressure system that had transitioned from a typhoon, rain fell primarily along the Pacific side of Eastern and Western Japan. On the 27th, affected by a low-pressure system and a front moving from south of Honshu toward the waters east of Japan, rain-concentrated in the morning-occurred along the Pacific side of regions from Tohoku to Kyushu. In Hokkaido, rain fell due to a low-pressure system moving eastward near Sakhalin. As the pressure pattern gradually shifted to a "west-high, east-low" configuration, rain also began to fall along the Sea of ??Japan side of Honshu. On the 28th, in the upper atmosphere... As a cold air mass moved in, the area experiencing snowfall expanded across Hokkaido, and the first snow of the season was recorded in Aomori Prefecture. Rain fell along the Sea of ??Japan side of Honshu. On the 29th, moist air flowing into the region-driven by the positioning of a high-pressure system and a pressure trough-brought rain to Northern Japan, the Kanto region, Kyushu, and Okinawa. On the 30th, influenced by moist air on the periphery of a high-pressure system, rain fell primarily along the Sea of ??Japan side of Northern to Western Japan; heavy rain was also observed in the Izu Islands during the early morning hours. On the 31st, thunderstorms occurred from Northern Japan through the Hokuriku region, fueled by warm, moist air flowing toward a low-pressure system over the Sea of ??Okhotsk, combined with a pressure trough carrying cold air across Northern and Eastern Japan.

# Temperatures
On the 25th, warm air flowed toward a weather front, leading to "midsummer-like" temperatures (30C or higher) in some areas, particularly in southern Kyushu. Conversely, as cold air moved into Hokkaido by the evening, many locations recorded new lows for the season. On the 26th, widespread rain across Eastern and Western Japan kept temperature increases minimal. On the 27th, despite rain falling in various regions from Hokkaido to Kyushu, periods of sunshine during the day allowed temperatures to rise, with many locations seeing temperatures above the seasonal average. On the 28th, a strong cold air mass descended over Northern Japan; in Sapporo, the daily high reached only 6.5C, and many other locations in the north saw highs in the single digits (Celsius). A "west-high, east-low" pressure pattern brought northerly winds nationwide, resulting in temperatures that were, in many places, below the seasonal average. On the 29th, cold air lingered over Honshu-primarily during the morning-which limited temperature increases even when the sun came out; "midsummer-like" temperatures (30C or higher) were confined to southern Kyushu and the Southwestern Islands. On the 30th, extensive cloud cover across Japan kept temperature increases sluggish. On the 31st, warm air that had flowed in from the south remained over Honshu; in parts of Eastern and Western Japan that saw sunshine, temperatures reached levels typical of early to mid-October.

Weekend weather: A winter-type pressure pattern is developing around Japan; be prepared for a sudden drop in temperatures in northern Japan.

2026/11/05 08:44

This weekend, a cold air mass is expected to move over Japan, creating a "winter-type" pressure pattern?characterized by high pressure to the west and low pressure to the east. Cold air will intensify rapidly, particularly across Northern Japan, leading to significant temperature fluctuations. Please take good care of your health and ensure you are well-prepared for the cold.

Weather Across Japan for Saturday, the 7th
On Saturday, the 7th, a low-pressure system will develop over the Sea of ??Okhotsk, while a high-pressure system extends from the Asian continent, resulting in a "high-to-the-west, low-to-the-east" pressure pattern across Japan. Due to a steep pressure gradient, caution is advised regarding strong winds, especially in Northern Japan.



A strong cold air mass?with temperatures at an altitude of 1,500 meters dropping to -9C or lower?will move over Hokkaido, bringing snow, primarily along the Sea of ??Japan coast. Snow is also possible in the Tohoku region.



Meanwhile, while many areas in Kyushu and along the Pacific coast of Honshu will see clear skies, the Sea of ??Japan side will experience unsettled weather, with rain or cloudy conditions.



In Northern Japan, daily high temperatures are expected to be around 8C lower than the previous day. In Hokkaido, many areas will see temperatures drop below freezing, while temperatures in the Tohoku region, northern Kanto, and the Hokuriku region will fall into the single digits. Given these significant temperature shifts, please be sure to prepare warm, heavy coats and take adequate measures to protect yourself from the cold. Weather for Sunday, the 8th
On Sunday, the 8th, the winter-type pressure pattern will persist, and cold air will remain in the upper atmosphere.
In Hokkaido, snow is expected in the northern regions and along the Sea of ??Japan coast. Snow is also likely in parts of Aomori Prefecture. While many areas along the Pacific coast?from Western Japan to Eastern Japan?will see clear skies, clouds will be more prevalent along the Sea of ??Japan coast, with periods of rain expected from the Hokuriku region through the Sea of ??Japan side of the Tohoku region.





Daytime temperatures will be even lower than on Saturday in many areas. Across the Tohoku region, northern Kanto, and the Hokuriku region, morning and evening temperatures will remain in the single digits (Celsius); please dress warmly if you are heading out this

Second Autumn Foliage Forecast for 2026: Peak viewing times in the lowlands of Western and Eastern Japan are expected to be later than average.

2026/11/05 07:19

In September of this year, frequent stagnation of the autumnal rain front near the main island of Japan (Honshu) resulted in limited sunshine, while average temperatures across the country remained near normal. In Eastern Japan, the influence of cool air caused some areas to experience temperatures below the seasonal average. In contrast, October saw Japan frequently covered by high-pressure systems, leading to temperatures that were generally near or above the seasonal average nationwide.

Looking ahead, temperatures from November onwards are expected to trend above average in Eastern and Western Japan; consequently, the peak of the autumn foliage season is likely to arrive later than usual. This will be particularly noticeable in lowland areas. Meanwhile, in Northern Japan, a strong cold air mass?unusually intense for this time of year?is expected to move in during early November, potentially bringing the peak of the autumn foliage to some areas either on schedule or earlier than usual.



Northern Japan
In Northern Japan, periods of cool air throughout October facilitated the steady progression of autumn foliage coloration. While many lowland areas in Hokkaido and the northern Tohoku region are currently at their peak, some parts of Hokkaido have already passed their peak, with leaves beginning to fall even in the lowlands.
Moving forward, a cold air mass is expected to move into the upper atmosphere in early November, likely resulting in temperatures that are near or below the seasonal average. In many locations, the peak of the autumn foliage is expected to arrive either on schedule or earlier than usual. We forecast the peak of the autumn foliage to occur around November 6 in Akita and around November 13 in Sendai.

Eastern Japan
In Eastern Japan, average temperatures throughout October were either near or above the seasonal norm. In many high-altitude mountainous areas, the autumn foliage is currently at its peak. As temperatures are expected to remain above average through November, the peak viewing period in many regions will likely be delayed compared to a typical year. In lowland areas, the peak is also expected to arrive either around the usual time or later than average.
We currently forecast the peak viewing period for Tokyo to be around November 30.

Western Japan
In Western Japan, average temperatures through October were near or above the seasonal norm, and this trend is expected to continue, with temperatures remaining above average throughout November. Nevertheless, many high-altitude mountainous areas are likely to reach their peak between mid- and late November.
In lowland areas, the peak is expected to arrive around the usual time or later than average, with many locations reaching their peak around December. Our current forecasts for the peak viewing period are approximately November 30 for Osaka, December 7 for Kochi, and December 2 for Fukuoka.

[Hokkaido] Rain expected across a wide area on the 5th; caution advised for heavy rain in the Iburi and Hidaka regions.

2026/11/04 17:32

Good evening. Here is the weather forecast for the Hokkaido region.
Today, Hokkaido was under the influence of a high-pressure system, resulting in clear skies across a wide area.



Although there were some scattered rain and snow showers in the Kamikawa and Rumoi areas, the weather is expected to gradually improve tonight.



Meanwhile, tomorrow, the 5th, the weather across the entire region is expected to deteriorate due to a low-pressure system moving toward the waters off the Sanriku coast, as well as an approaching pressure trough.



Expect cloudy skies and rain in the central, eastern, and southern parts of Hokkaido,
with the possibility of heavy rainfall in the Iburi and Hidaka regions.



Additionally, please be cautious of strong winds, as the pressure gradient will increase. If you are heading out tomorrow, please bring a large umbrella.
That concludes the weather forecast for the Hokkaido region.

Significant rainfall expected tomorrow, the 5th; short-sleeved attire might be appropriate on Friday the 6th, with unseasonably warm weather in Tokyo.

2026/11/04 16:49

Tomorrow, the 5th, a pressure trough is expected to form over the main island of Honshu. Additionally, a low-pressure system accompanied by a front will likely pass across the region.

Furthermore, warm, moist air flowing in from Typhoon No. 31-which is moving north-northeast south of Japan-will cause atmospheric conditions to become unstable, leading to rain across the country.

Active rain clouds may develop, potentially causing temporary intensifications in both rainfall and wind. Please stay tuned for the latest weather updates.



On Friday the 6th, a ""winter-type"" pressure pattern-characterized by high pressure to the west and low pressure to the east-will set in, likely resulting in continued rough weather across northern Japan.
Meanwhile, conditions from the Kanto region westward will improve; as warm air flows in following the passage of the low-pressure system, temperatures in the Kanto region are expected to rise.



In Tokyo, the high is expected to reach 26C-a level of warmth typical of late September.
During the day, it may feel too hot in long sleeves, making short-sleeved clothing a more comfortable choice.



Temperatures will fluctuate significantly during the latter half of the week. Please take care of your health and dress in layers that are easy to put on or take off, so you can adjust accordingly."

[Kanto Region] Rain to intensify from this evening; caution advised for heavy rain and strong winds tomorrow, the 5th (Report by AI presenter)

2026/11/04 12:45

Here is the weather forecast for the Kanto region.
While the area around Honshu is under the influence of a weak high-pressure system, there is a trough of low pressure near the Izu Islands.



Today, the 4th, the Kanto region is covered in thick clouds due to a trough of low pressure and the influx of moist air.
Currently, it is cloudy across the Kanto region, with some areas experiencing light, scattered rain. By this evening, the rain is expected to become more steady. If you are returning home late, it would be a good idea to carry a large umbrella.



Tomorrow, a low-pressure system is expected to form off the Boso Peninsula, leading to highly unstable atmospheric conditions. From tomorrow morning through the evening, there is a risk of intensifying rain and stronger winds across the Kanto region, so please stay updated with the latest weather information.



From the day after tomorrow onwards, there are no major weather disturbances expected, and we can look forward to more days with sunshine.

https://youtu.be/pYS8L_VHcTA?si=4JB4oX1lL8MlXBWz

[Typhoon Names] Who decides the names of typhoons? How are Asian names for typhoons determined?

2026/11/03 20:29

Typhoon No. 31, which formed in the Marshall Islands on Saturday, October 15, is named "In-fa." This name-appearing in news reports-is known as an "Asian name." These names have been used since 2000 with the goals of respecting the cultures of various Asian nations and regions, strengthening solidarity, promoting mutual understanding, and raising public awareness regarding disaster prevention.

A sequence of 140 names
The "Typhoon Committee"-comprising 14 countries and regions, including Japan-has compiled a list of 140 names, with each member contributing 10. When a typhoon forms in the Northwest Pacific or the South China Sea, it is assigned a name from this list in sequential order. The first name used was "Damrey" (meaning "elephant" in the Cambodian language) for the first typhoon of 2000; once all 140 names have been used, the cycle begins again from "Damrey." Given that the annual average number of typhoons is 25.1, the full list cycles through approximately every 5 to 6 years.

A system distinct from "numbering"
Typhoon numbers are assigned by the Japan Meteorological Agency (JMA) based on the order in which typhoons form from January 1st of each year. If a typhoon weakens into a tropical depression and subsequently re-intensifies, it retains its original number. In contrast, names are assigned according to their position on the list, meaning the same name does not necessarily recur every year. Typhoon No. 31, "In-fa"-which formed on Saturday, October 24-was proposed by Macau and means "fireworks." Within Japan, typhoons are typically referred to by their numbers, while in English-language contexts, their names are used.

Japan's contributions: Constellation names
All 10 names proposed by Japan are derived from constellations: Canis Minor (Little Dog), Puppis (Stern), Serpens (Serpent), Dorado (Swordfish), Lyra (Harp), Cetus (Whale), Ursa Minor (Little Bear), Horologium (Clock), Lacerta (Lizard), and Lynx (Wildcat). Typhoon No. 29, "Koguma," which formed on October 5, was named after the constellation Ursa Minor (the Little Bear). The name was chosen because it is "neutral" and familiar to people, rather than being based on a person's name, a geographical location, or a meteorological phenomenon. Criteria for these names include being no more than nine letters long, being easy to pronounce, and having no offensive meanings in the languages ??of other countries or regions.

Unique Names
Some names are quite unique: "Dim-sum" (from Hong Kong) refers to the well-known Cantonese cuisine; "Babinka" (from Macau) is a type of pudding; and "Neoguri" (from South Korea) means "raccoon dog." The list includes a wide variety of names, ranging from plants, animals, and food to figures from mythology.

Names That Are "Retired"
When a typhoon causes a major disaster, its name may be retired-meaning it will no longer be used-at the request of a member country or region. For example, the names "Faxai" (Typhoon No. 15, 2019) and "Hagibis" (Typhoon No. 19, 2019)-both of which caused extensive power outages, including in Chiba Prefecture-have been retired.

Names for "Cross-Boundary" Typhoons
In the case of a "cross-boundary" typhoon-a hurricane that crosses the 180th meridian (the International Date Line) and becomes a typhoon-the responsibility for tracking it shifts from the Central Pacific Hurricane Center (in the U.S.) to the Japan Meteorological Agency (JMA). If the maximum sustained wind speed is 17.2 m/s or greater, it is classified as a typhoon.
In such cases, the name is not taken from the standard list of Asian typhoon names; instead, the name originally assigned to it is retained.
"Nolo," which became a cross-boundary typhoon on October 5 of this year, is one such example.