Inflow forecast
model output — not a measurementNOAA’s National Water Model, short-range run issued Sep 9, 12 PM EDT, for the 2 gauged tributary reaches feeding Lake Lanier. The model routes rainfall that has already fallen plus near-term forecast precipitation.
Gauged inflow now
262
cfs · measured
Peak next 18h
301.6
cfs · ~6 AM EDT · modeled
Projected volume
411
acre-feet over 18h · modeled
Net lake effect
-0.01 ft
after 606 cfs out · inferred
Projected flow by tributary reach
Dashed = forecast. Values are at the gauges, not at the lake — water takes hours to a couple of days to travel downstream from the gauges to the lake. National Water Model via NOAA/NWS · public domain.
The “net lake effect” nets the projected inflow volume against the water currently leaving the lake (606 cfs — Chattahoochee below Buford Dam, right now), held constant over the horizon, spread over the lake’s estimated surface area (before releases it would be +0.01 ft). It ignores travel time, channel losses, and any change the dam operators make — a scale reference, not a prediction. During floods, watch the live dashboard instead.