an uncountable noun
Indefinite Articles with Uncountable Nouns Grammarly
Uncountable nouns are nouns that are either difficult or impossible to
count. Uncountable nouns include intangible things (e.g., information,
air), liquids (e.g., milk, wine), and things that are too large or
numerous to count (e.g., equipment, sand, wood). Because these things
can’t be counted, you should never use a or an with them—remember, the
indefinite article is only for singular nouns. Uncountable nouns can
be modified by words like some, however.
This is the case for landfall. Over time English has abandoned written articles a, an and the. Many 'rules' for their usage abound. Their use or lack of use is not a 'fatal' grammatical error. The written over time mirrors the spoken.