Definition
A pilot weather report classified as urgent because it contains hazardous conditions that may pose immediate risk to other aircraft. UUA reports are transmitted by air traffic facilities as soon as received, without waiting for routine processing. Conditions that warrant a UUA include tornadoes, funnel clouds, waterspouts, severe or extreme turbulence, severe icing, hail, low-level wind shear, volcanic ash, and any weather phenomenon the pilot judges to be hazardous.
Plain English
A pilot's report of dangerous weather that needs to go out right away so other aircraft hear about it without delay.
Context Anchor
You may see UUA in aviation weather briefings, weather displays, or FAA weather products that include pilot reports.
Derivation
PIREP is short for Pilot Report. The two coding letters distinguish the type: UA is a routine pilot report, and UUA is the urgent version. The doubled U is simply the coding convention for 'urgent' in the PIREP system.
Why Pilots Care
Urgent PIREPs let pilots change route or altitude quickly to stay out of hazardous weather.
Intuition Check
Do not read “urgent” as just “somewhat important.” In this term, it means the report contains a hazard serious enough to be passed along quickly.
Example Sentence 1
After encountering severe turbulence at 12,000 feet, the pilot called Flight Watch and the report was disseminated as a UUA.
Example Sentence 2
The pilot filed a UUA after encountering heavy icing on the approach.