The mountains store it. The San Juan tells the rest.
Explore 39 years of snowpack and river flow. Compare seasons, then read the story behind the water.
1.2.0
SNOW & FLOW EXPLORER
Different years. The same calendar.
Water years begin October 1.
More comparison options
Preparing the current-season comparison…
Hover to preview. Click or tap to select a date for both charts and the comparison below.
The plots share a calendar. River flow uses a log scale in CFS; snow water equivalent uses a linear scale in inches. SWE is the daily average of Upper San Juan and Wolf Creek Summit. Gaps stay visible; missing data never becomes zero.
AT THE SAME POINT IN THE SEASON
The comparison
Water year
Flow on date
Snow water on date
Peak snow water so far
Next 30 days: historic mean flow
“Next 30 days” shows what actually followed in a past season, where at least 25 daily readings are available. It stays blank for the current season. These comparisons inform a judgment; they are not a new Black Hat forecast.
This is the Lab’s fourth standalone section: the completed river record, not a prediction scoreboard. Choose a year for its plain-language season story, October–September snow-and-flow hydrograph and Mother Nature’s answer to all eight questions the Black Hat now predicts.
LOADING THE ARCHIVE
Building the historic season catalog…
Stories follow the archived snow and daily river records. Gauge-based handoff dates are estimates; recorded Pagosa Outside openings are identified where available. The 2026 story also includes local operating history.
MOTHER NATURE’S EIGHT ANSWERS
From first snow to the last summer float
Snowpack
1 · WHEN DID SNOW STICK?--How this is measured
The first seven-day start with at least 1 inch of average SWE and no day below 0.5 inch.
2 · HOW MUCH WATER DID THE SNOWPACK HOLD?--How this is measured
Each year’s finished peak compared with the average annual peak.
Rafting
3 · WHEN DID RAFTING WATER ARRIVE?--How this is measured
First daily mean at 400 CFS or more.
4 · WHAT KIND OF RAFTING SEASON WAS IT?--How this is measured
The full May–June hydrograph supplies the season grade.
5 · WHEN AND HOW HIGH DID RUNOFF PEAK?--How this is measured
Highest instantaneous Pagosa gauge reading, with local time.
6 · HOW LONG DID RAFTING WATER LAST?--How this is measured
Operating-season days at 300+, 600+ and 800+ CFS.
Tubing
7 · WHEN DID TUBING WATER ARRIVE?--How this is measured
Recorded opening when available; otherwise the gauge handoff.
8 · HOW LONG DID TUBING WATER LAST?--How this is measured
Days at 30–399 CFS after opening through the Sunday before Labor Day.
OPEN THE HYDROLOGY LOGDaily means, middle-water range and exact rules
DAILY-MEAN SPRING PEAK--MAY–JUNE AVERAGE--FIRST DAILY 400+--DAYS AT 600+--GAUGE HANDOFF BELOW 400--SPRING TEMPERATURE--SNOW GAIN AFTER APRIL 1--
The historic graph and counts use archived daily-mean flow at the Pagosa USGS gauge. Peak SWE is the daily average of Upper San Juan and Wolf Creek Summit. Historic peak percentage compares each finished year’s peak with the 1991–2020 average annual peak of 31.9 inches; the live winter Lab continues to use date-to-date percent of normal. Instantaneous peak is separate from the daily-mean hydrograph; the game’s spring-peak card uses the instantaneous crest.
The archive translates gauge and SNOTEL records into recreation language. “Rafting day” means a May 1–Labor Day daily mean of 300+ CFS; bigger-water counts use 600+ and 800+. The monsoon epilogue counts July–August days back at 300+ after tubing water arrived. These describe available water—not a trip log, staffing record or guarantee that an activity operated.
