Morel Signal

What This App Is

Graph-first seasonal view using modeled weather and soil data from Open-Meteo forecast and historical datasets [2,3]. Set your location using the map picker (click or drag the pin, or enter coordinates directly). Location is saved between sessions.

What The Two Graphs Show

Two views answer different questions:

• Predicted Soil Temp: modeled daily soil-temperature path from season start through the forecast horizon, with optional thaw-window shading and rainfall-event bars for context [2,3].
• Season Progression: cumulative modeled soil degree-days above 32°F in the season window, compared against the Published Onset Reference Band from the literature [1]. This drives Onset Band Position.

Predicted Soil Temp Logic

Modeled daily soil-temperature path from the season window through the available forecast horizon [2,3]. Solid line is historical data; dashed segment is forecast. The two connect at today. The freeze/thaw line marks 32°F. These values are environmental context (not the same as the cumulative degree-day reference band).

• Show thaw-window shading: highlights continuous runs where modeled soil stays above 32°F, capped at 30 days. A visible border on a shaded region means the thaw window hit the 30-day cap. Visual aid, not a published predictor.
• Show rainfall events: daily rain bars in inches for both history and forecast. Context only, not a direct onset calculation.

Season Progression Logic

Uses a fixed default window of Jan 1 to Jun 30 and accumulates modeled soil degree-days above 32°F within that window. An optional custom start date is available under Advanced Season Settings. The running total is compared to the Published Onset Reference Band from the morel literature [1].

• Onset Band Position = Pre-Range: below roughly 365 F-days
• Onset Band Position = In Range: roughly 365 to 580 F-days
• Onset Band Position = Beyond Onset Range: above roughly 580 F-days (not a hard season-ending signal)

Season Stage Logic

Season Stage is a calendar-based operational guide for this app's target region profile. Separate from Onset Band Position.

• Preseason: Jan 1 to Mar 31
• Early Ramp: Apr 1 to Apr 14
• Primary Window: Apr 15 to May 31
• Late Window: Jun 1 to Jun 15
• Low Likelihood: Jun 16 to Jun 30
• Off Season: Jul 1 onward

What Is Research-Backed vs Heuristic

• More supported: cumulative soil warming matters for onset timing; the 365 to 580 F-day band is the main published reference in this app [1].
• Heuristic: Season Stage date bands and thaw-window shading.
• Context only: rainfall bars and soil trace overlays are not direct onset calculations.
• Data limitation: this app uses modeled soil temperature from Open-Meteo, not direct in-ground sensor readings [2,3].

References

• [1] Mihail, Bruhn, and Bonello (2007), Spatial and temporal patterns of morel fruiting. Main field-study anchor for soil temperature and rain-event logic. DOI, ScienceDirect
• [2] Open-Meteo Forecast API docs. Source for the live forecast and recent weather data used by this app. Forecast Docs
• [3] Open-Meteo Historical Weather API docs. Source for historical weather variables including humidity, dew point, precipitation, and soil temperature layers. Historical Docs
• [4] Masaphy (2010), Biotechnology of morel mushrooms: successful fruiting body formation and development in a soilless system. Useful as background that temperature and moisture conditions matter, though it is cultivation-focused rather than a wild-field predictor. PubMed
• [5] Du et al. (2015), A review on research advances, issues, and perspectives of morels. Broad morel review for ecological and research context. PMC