Arwen.

This is coolbert:

From Cassius Dio. 

"[56.20.3] 'Meanwhile a violent rain and wind came up that separated them [Romans] still further, while the ground, that had become slippery around the roots and logs, made walking very treacherous for them, and the tops of the trees kept breaking off and falling down, causing much confusion.'

[56.21.3] 'They [Romans] were still advancing when the fourth day dawned, and again a heavy downpour and violent wind assailed them, preventing them from going forward and even from standing securely, and moreover depriving them of the use of their weapons. For they [Romans] could not handle their bows or their javelins with any success, nor, for that matter, their shields, which were thoroughly soaked.'" - - Cassius Dio, Chapters 18-24 of Book 56 . 

As it was in Germania 9 A.D., as it was in Great Britain 2021 A.D.? The EXTRATROPICAL CYCLONE!

Destruction of the three Roman legions [9 A.D.] at the Battle of the Teutoburger Wald in large measure the Germanic barbarian warriors greatly aided and abetted by extreme foul and unnatural weather conditions.

"More than eight million trees lost this winter in the UK"

Thanks to the BBC the article by Claire Marshall.

FORESTS THE UNITED KINGDOM DEVESTATED BY STORMS OF CYCLONE PROPORTIONS. IMMENSIVELY DESTRUCTIVE. THIS WAS STORM ARWEN.

"Forest ranger Richard Tanner says that he's never seen a real battlefield, but the west shore of Windermere now reminds him of photographs he has seen."

"Storm Arwen was a powerful extratropical cyclone that was part of the 2021–22 European windstorm season. It affected the United Kingdom, Ireland and France, bringing strong winds and snow. Storm Arwen caused at least three fatalities and widespread power outages. Damage was exacerbated by the fact that the strong winds came unusually from the north.

SEE THE BBC ARTICLE WITH ACCOMPANYING IMAGES. YES, LIKE A BATTLEFIELD!

The Germanic tribesmen by close observation of the cloud formations could ANTICIPATE the storm and take advantage of the situation? I believe this is probably so.

coolbert.