INDIANAPOLIS, Indiana — Farm families across the lower Great Lakes and Ohio Valley who have endured one of the wettest stretches of the harvest season in recent memory are finally getting some good news. The dry gap forecast for September 24 through September 29, 2026 is holding firm in both major forecast models, with data continuing to show a drier window across the Eastern Ag Belt and Ohio Valley that will allow fields to begin drying out and harvest equipment to get back to work. Both the GFS and European models agree on the broad outline of this dry period, though slight timing differences exist around the September 28 through September 29 front that will eventually end the dry stretch.
What Both Models Show for September 24 Through September 29
The side-by-side forecast maps show remarkable agreement between the two models on the dry gap across the lower Great Lakes and Ohio Valley:
GFS Model — September 24 Through September 29:
- Milwaukee, Wisconsin is forecast at just 0.05 inches of total rainfall through the dry gap period.
- Chicago, Illinois is forecast at near zero rainfall through the September 24 through September 29 window — an extraordinary contrast to the multi-inch totals the city has seen this past week.
- Indianapolis, Indiana and Cincinnati, Ohio show near-dry conditions on the GFS model through September 29, 2026.
- Pittsburgh, Pennsylvania and Cleveland, Ohio show minimal rainfall on the GFS through the dry gap period.
- Nashville, Tennessee and Knoxville, Tennessee show very light totals on the GFS model through September 29.
- Atlanta, Georgia and Columbia, South Carolina are forecast at approximately 0.05 inches on the GFS through the dry gap.
- Memphis, Tennessee shows a slightly wetter signal at approximately 0.60 inches on the GFS model, sitting near a front boundary that carries some moisture through the period.
- St. Louis, Missouri shows approximately 0.64 inches on the GFS near the same frontal boundary visible in the mid-section of the model output.
- Raleigh, North Carolina shows approximately 0.25 inches on the GFS through September 29, 2026.
- Jackson, Mississippi is forecast at approximately 0.13 inches on the GFS model through the dry gap period.
- New Orleans, Louisiana is forecast at approximately 0.01 inches on the GFS through September 29.
- Jacksonville, Florida is forecast at approximately 0.05 inches on the GFS model through the dry gap.
- Minneapolis, Minnesota is forecast at approximately 0.17 inches on the GFS through September 29, 2026.
- New Orleans area shows 0.32 inches on the European model for the same period.
- Baton Rouge, Louisiana is forecast at approximately 0.32 inches on the European model through September 29.
European Model — September 24 Through September 29:
- Chicago, Illinois shows near-dry conditions confirming the dry gap on the European model as well, with readings near zero through the September 24 through September 29 window.
- Indianapolis, Indiana and Cincinnati, Ohio confirm near-dry conditions on the European model through September 29, 2026.
- Pittsburgh, Pennsylvania is forecast at approximately 0.05 inches on the European model, confirming the dry gap extends into western Pennsylvania.
- Cleveland, Ohio shows approximately 0.01 inches on the European model through the dry gap period.
- Milwaukee, Wisconsin is forecast at approximately 0.05 inches on the European model through September 29, 2026.
- Nashville, Tennessee is forecast at approximately 0.05 inches on the European model confirming the dry gap extends into Tennessee.
- Knoxville, Tennessee is forecast at approximately 0.05 inches on the European model through September 29.
- Atlanta, Georgia falls within the dry zone on the European model through the September 24 through September 29 window.
- Charleston, West Virginia is forecast at approximately 0.01 inches on the European model through the dry gap period.
- Jacksonville, Florida is forecast at approximately 0.05 inches on the European model through September 29, 2026.
What This Dry Gap Means for Harvest Operations
After one of the most disruptive wet stretches in recent harvest season memory, a 6-day dry window from September 24 through September 29 across the lower Great Lakes and Ohio Valley is genuinely significant. Fields that have been too wet for combines to operate without causing costly soil compaction can begin the drying process immediately once the current rainfall pattern ends. Depending on soil type and drainage, many fields across Indiana, Ohio, Illinois and Kentucky could be ready for harvest equipment within 2 to 4 days of dry conditions setting in after September 23. This makes the September 26 through September 29 window the most likely period for meaningful harvest progress across the Eastern Ag Belt — the first real opportunity in over a week for farm operations to catch up on lost days.
The Timing Question Around September 28 and 29
The source data acknowledges slight timing differences between models around the September 28 through September 29 front that will eventually bring the next round of rainfall to the region. The GFS and European models agree on the dry gap but differ slightly on exactly when the next front arrives at the tail end of the window. For farmers planning harvest operations, the core dry window of September 24 through September 27 appears to have the strongest model agreement and the most reliable dry conditions. The September 28 through September 29 stretch carries slightly more uncertainty depending on how quickly the next front arrives from the west.
