What Does FROPA Mean in a METAR?
FROPA means frontal passage: a front moved across the station. It stands for FROntal PAssage.
FROPA in a real report
WSHFT 1715 FROPA
What it changes for you
FROPA is the observer telling you the weather change had a cause, and that
the cause is moving.
That distinction matters for planning. A wind shift on its own might be local
and temporary. A wind shift with FROPA is part of a system that will reach the
next field down your route, at a speed you can estimate from the stations behind
you.
Reading the sequence
The useful move is to look at the stations upstream. If the field 60 miles
upwind reported FROPA two hours ago and yours has just reported it, you have a
speed. That tells you roughly when the field ahead gets the same thing.
Related codes
Decode a report containing this code
Paste a METAR, TAF, PIREP or SIGMET into the WxDecoder decoder. Every group comes back in plain English. The raw code sits beside it, so you can check the decode rather than trust it.
Frequently asked questions
What does FROPA mean in a METAR?
Frontal passage. A front moved across the station during the observation period. It appears in the remarks, often beside a wind shift, and tells you the change in conditions has a cause that is still moving.
Does FROPA mean conditions will improve?
Not by itself. It says a front passed. What follows depends on the type of front. A cold frontal passage often brings clearing with gusty shifted winds, while a warm front can leave low cloud behind it.