Details from the National Weather Service
* WHAT...Temperatures as low as 35 will result in frost formation. * WHERE...Portions of northern Indiana and northwest Ohio. * WHEN...From 1 AM EDT /midnight CDT/ to 9 AM EDT /8 AM CDT/ Monday. * IMPACTS...Frost could harm sensitive outdoor vegetation. Sensitive outdoor plants may be killed if left uncovered. Take steps now to protect tender plants from the cold.
Forecast insight run of Sun Oct 18, 8:11 PM
Everything behind the hyper-local forecast for this run: the raw guidance, the ensemble spread, how and why our numbers differ from the models, and how the forecast has been changing. Rebuilt every hour from the same data that produced the forecast.
| Input | Last fetched | Notes |
|---|---|---|
| Global models | 57 min ago | GFS, ECMWF, ICON, GEM, NBM |
| Upper air & stability | 57 min ago | 850 mb temperature, CAPE, freezing level, mixing height |
| Ensembles | 57 min ago | GEFS 31 · ECMWF ENS 51 · ICON-EPS 40 members |
| HRRR | 57 min ago | storm-resolving, next ~2 days |
| NWS | 1.6 h ago | IWX gridpoint forecast for this point |
| Forecast discussion | 30.5 h ago | NWS Northern Indiana, read by an AI model on the station computer; used in rain chances |
| WxSim | run of Oct 18, 1 PM | local column model run on the station PC |
Model version 2026-10-14, trained through 2026-10-13.
Forecast discussion
The written discussion of this run, why the forecast says what it says, is on the Forecast page.
Day by day: guidance, our forecast and the ensemble
| Period | GFS | ECMWF | ICON | GEM | NBM | Model average | Our forecast | NWS | WxSim | Ensemble low / middle / high | |||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sunday, Oct 18 · High | period over | - | observed 68° | - | |||||||||||||||||||||||||||||||||||||||||||||
| Sunday, Oct 18 · Low (night) | 37.3 | 39.8 | 38.2 | 36.0 | 38.5 | 37.8 | 36° ±3 underway: 35° with the station |
36° | 36° | 35° / 39° / 43° | |||||||||||||||||||||||||||||||||||||||
Why ours is −2.0° from the blend
Start with the models' average, add each row (blue pushed it warmer, orange cooler), and you arrive at our forecast. Each row compares this period with an ordinary one: a factor that is typical adds nothing. The rows are rounded, so adding them by hand can be off by a tenth. | |||||||||||||||||||||||||||||||||||||||||||||||||
| Monday, Oct 19 · High | 67.4 | 64.4 | 65.8 | 64.7 | 65.7 | 65.6 | 68° ±3 | 68° | 68° | 64° / 65° / 66° | |||||||||||||||||||||||||||||||||||||||
Why ours is +2.5° from the blend
Start with the models' average, add each row (blue pushed it warmer, orange cooler), and you arrive at our forecast. Each row compares this period with an ordinary one: a factor that is typical adds nothing. The rows are rounded, so adding them by hand can be off by a tenth. | |||||||||||||||||||||||||||||||||||||||||||||||||
| Monday, Oct 19 · Low (night) | 38.4 | 41.8 | 40.2 | 38.4 | 40.3 | 39.7 | 38° ±3 | 38° | 36° | 37° / 41° / 45° | |||||||||||||||||||||||||||||||||||||||
Why ours is −1.5° from the blend
Start with the models' average, add each row (blue pushed it warmer, orange cooler), and you arrive at our forecast. Each row compares this period with an ordinary one: a factor that is typical adds nothing. The rows are rounded, so adding them by hand can be off by a tenth. | |||||||||||||||||||||||||||||||||||||||||||||||||
| Tuesday, Oct 20 · High | 66.5 | 66.3 | 67.7 | 67.4 | 67.3 | 67.0 | 70° ±3 | 69° | 69° | 65° / 66° / 68° | |||||||||||||||||||||||||||||||||||||||
Why ours is +2.7° from the blend
Start with the models' average, add each row (blue pushed it warmer, orange cooler), and you arrive at our forecast. Each row compares this period with an ordinary one: a factor that is typical adds nothing. The rows are rounded, so adding them by hand can be off by a tenth. | |||||||||||||||||||||||||||||||||||||||||||||||||
| Tuesday, Oct 20 · Low (night) | 46.1 | 42.7 | 40.1 | 37.9 | 41.6 | 41.7 | 40° ±4 | 41° | 39° | 38° / 43° / 45° | |||||||||||||||||||||||||||||||||||||||
Why ours is −1.6° from the blend
Start with the models' average, add each row (blue pushed it warmer, orange cooler), and you arrive at our forecast. Each row compares this period with an ordinary one: a factor that is typical adds nothing. The rows are rounded, so adding them by hand can be off by a tenth. | |||||||||||||||||||||||||||||||||||||||||||||||||
| Wednesday, Oct 21 · High | 66.9 | 66.3 | 66.5 | 66.1 | 67.4 | 66.5 | 71° ±3 | 70° | 71° | 60° / 65° / 68° | |||||||||||||||||||||||||||||||||||||||
Why ours is +4.7° from the blend
Start with the models' average, add each row (blue pushed it warmer, orange cooler), and you arrive at our forecast. Each row compares this period with an ordinary one: a factor that is typical adds nothing. The rows are rounded, so adding them by hand can be off by a tenth. | |||||||||||||||||||||||||||||||||||||||||||||||||
| Wednesday, Oct 21 · Low (night) | 47.8 | 43.2 | 42.9 | 35.6 | 42.8 | 42.4 | 40° ±5 | 42° | 38° | 38° / 43° / 48° | |||||||||||||||||||||||||||||||||||||||
Why ours is −2.4° from the blend
Start with the models' average, add each row (blue pushed it warmer, orange cooler), and you arrive at our forecast. Each row compares this period with an ordinary one: a factor that is typical adds nothing. The rows are rounded, so adding them by hand can be off by a tenth. | |||||||||||||||||||||||||||||||||||||||||||||||||
| Thursday, Oct 22 · High | 67.6 | 65.4 | 66.5 | 67.1 | 68.5 | 66.7 | 70° ±4 | 71° | 70° | 62° / 65° / 68° | |||||||||||||||||||||||||||||||||||||||
Why ours is +3.4° from the blend
Start with the models' average, add each row (blue pushed it warmer, orange cooler), and you arrive at our forecast. Each row compares this period with an ordinary one: a factor that is typical adds nothing. The rows are rounded, so adding them by hand can be off by a tenth. | |||||||||||||||||||||||||||||||||||||||||||||||||
| Thursday, Oct 22 · Low (night) | 49.7 | 44.6 | 45.9 | 36.3 | 45.7 | 44.1 | 43° ±6 | 45° | 38° | 39° / 44° / 49° | |||||||||||||||||||||||||||||||||||||||
Why ours is −1.5° from the blend
Start with the models' average, add each row (blue pushed it warmer, orange cooler), and you arrive at our forecast. Each row compares this period with an ordinary one: a factor that is typical adds nothing. The rows are rounded, so adding them by hand can be off by a tenth. | |||||||||||||||||||||||||||||||||||||||||||||||||
| Friday, Oct 23 · High | 68.5 | 62.1 | 64.0 | 68.0 | 67.3 | 65.7 | 68° ±6 | 67° | - | 51° / 63° / 68° | |||||||||||||||||||||||||||||||||||||||
Why ours is +2.5° from the blend
Start with the models' average, add each row (blue pushed it warmer, orange cooler), and you arrive at our forecast. Each row compares this period with an ordinary one: a factor that is typical adds nothing. The rows are rounded, so adding them by hand can be off by a tenth. | |||||||||||||||||||||||||||||||||||||||||||||||||
| Friday, Oct 23 · Low (night) | 49.3 | 39.9 | 37.1 | 37.2 | 42.5 | 40.9 | 41° ±7 | 42° | - | 36° / 42° / 47° | |||||||||||||||||||||||||||||||||||||||
Why ours is −0.1° from the blend
Start with the models' average, add each row (blue pushed it warmer, orange cooler), and you arrive at our forecast. Each row compares this period with an ordinary one: a factor that is typical adds nothing. The rows are rounded, so adding them by hand can be off by a tenth. | |||||||||||||||||||||||||||||||||||||||||||||||||
| Saturday, Oct 24 · High | 70.2 | 62.7 | 66.5 | 68.0 | 67.2 | 67.0 | 68° ±7 | 68° | - | 51° / 62° / 69° | |||||||||||||||||||||||||||||||||||||||
Why ours is +0.8° from the blend
Start with the models' average, add each row (blue pushed it warmer, orange cooler), and you arrive at our forecast. Each row compares this period with an ordinary one: a factor that is typical adds nothing. The rows are rounded, so adding them by hand can be off by a tenth. | |||||||||||||||||||||||||||||||||||||||||||||||||
| Saturday, Oct 24 · Low (night) | 56.6 | 45.9 | 41.7 | 40.9 | 45.7 | 47.8 | 47° ±8 | 45° | - | 38° / 46° / 54° | |||||||||||||||||||||||||||||||||||||||
Why ours is −1.3° from the blend
Start with the models' average, add each row (blue pushed it warmer, orange cooler), and you arrive at our forecast. Each row compares this period with an ordinary one: a factor that is typical adds nothing. The rows are rounded, so adding them by hand can be off by a tenth. | |||||||||||||||||||||||||||||||||||||||||||||||||
Daytime high is 7 AM to 7 PM, overnight low is 7 PM to 8 AM (standard time). Model columns are each model's value for that window at this station's grid point; Blend is the average of GFS, ECMWF, ICON and GEM that our correction starts from. Open "why" to see how much each factor moved our number away from the blend.
Where our forecast sits
Every forecaster on one temperature line for each day, so you can see at a glance who ours agrees with, whether it sits inside the ensemble's range, and when it goes its own way.
Hover a marker for its name and value. The dashed line in each row is our forecast.
Precipitation by 12-hour period
| Period | Our forecast | NWS | ≥0.01″ | ≥0.10″ | ≥0.25″ | ≥0.50″ | ≥1.00″ | Ensemble middle | Ensemble high | Ensemble runs with rain (GEFS / ECMWF / ICON) | CAPE | Freezing level |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sunday, Oct 18 · day | period over · measured 0.00″ | |||||||||||
| Sunday, Oct 18 · night | 8% | 0% | 0% | 0% | 0% | 0% | 0% | 0.00″ | 0.00″ | 0% / 0% / 0% | 0 | 11,800 ft |
| Monday, Oct 19 · day | 5% | 0% | 0% | 0% | 0% | 0% | 0% | 0.00″ | 0.00″ | 0% / 0% / 0% | 0 | 11,700 ft |
| Monday, Oct 19 · night | 9% | 0% | 0% | 0% | 0% | 0% | 0% | 0.00″ | 0.00″ | 0% / 0% / 0% | 0 | 11,300 ft |
| Tuesday, Oct 20 · day | 5% | 0% | 0% | 0% | 0% | 0% | 0% | 0.00″ | 0.00″ | 0% / 0% / 0% | 0 | 11,000 ft |
| Tuesday, Oct 20 · night | 8% | 0% | 0% | 0% | 0% | 0% | 0% | 0.00″ | 0.00″ | 0% / 0% / 0% | 0 | 11,300 ft |
| Wednesday, Oct 21 · day | 6% | 0% | 0% | 0% | 0% | 0% | 0% | 0.00″ | 0.00″ | 0% / 0% / 0% | 0 | 11,300 ft |
| Wednesday, Oct 21 · night | 8% | 0% | 0% | 0% | 0% | 0% | 0% | 0.00″ | 0.00″ | 0% / 0% / 0% | 0 | 11,400 ft |
| Thursday, Oct 22 · day | 6% | 0% | 0% | 0% | 0% | 0% | 0% | 0.00″ | 0.00″ | 0% / 0% / 0% | 0 | 11,600 ft |
| Thursday, Oct 22 · night | 8% | 1% | 0% | 0% | 0% | 0% | 0% | 0.00″ | 0.00″ | 0% / 0% / 0% | 0 | 11,200 ft |
| Friday, Oct 23 · day | 6% | 0% | 0% | 0% | 0% | 0% | 0% | 0.00″ | 0.00″ | 0% / 0% / 0% | 10 | 11,100 ft |
| Friday, Oct 23 · night | 8% | 0% | 0% | 0% | 0% | 0% | 0% | 0.00″ | 0.00″ | 0% / 0% / 0% | 0 | 11,100 ft |
| Saturday, Oct 24 · day | 8% | 0% | 0% | 0% | 0% | 0% | 0% | 0.00″ | 0.00″ | 0% / 0% / 0% | 0 | 11,400 ft |
| Saturday, Oct 24 · night | 13% | 0% | 0% | 0% | 0% | 0% | 0% | 0.00″ | 0.00″ | 0% / 0% / 0% | 0 | 11,600 ft |
"Ours" is the chance of at least 0.01″ in this gauge, calibrated to how often model rain has actually reached it. Threshold columns are the share of all ensemble members reaching each amount; median and 90th are their totals. When the three ensemble systems disagree sharply, treat any single number with caution. CAPE is the highest of the models in the period; freezing level is the lowest. Snow columns appear when any member produces snow.
Run-to-run trend last 4 days of runs
How each upcoming day's forecast has moved from run to run. A steady line means the guidance has settled; a drifting one means the models are still converging, and the forecast deserves less trust.
Solid: daytime high; dashed: overnight low. Blue is ours, green NWS, cyan WxSim. Each point is one hourly run. History builds up as the forecast runs, so this fills in over the first few days.
Recent verification today's and tonight's forecast vs the station
| Period | Observed | Our forecast | NWS | WxSim | Model average |
|---|---|---|---|---|---|
| Wednesday, Oct 14 · low | 58° | 58° +0 | 56° -2 | - | 58° +0 |
| Thursday, Oct 15 · high | 67° | 70° +3 | 71° +4 | 71° +4 | 69° +2 |
| Thursday, Oct 15 · low | 53° | 53° +0 | 50° -3 | 57° +4 | 54° +1 |
| Friday, Oct 16 · high | 54° | 57° +3 | 57° +3 | 62° +8 | 56° +2 |
| Friday, Oct 16 · low | 36° | 36° +0 | 35° -1 | 37° +1 | 37° +1 |
| Saturday, Oct 17 · high | 56° | 55° -1 | 54° -2 | 60° +4 | 53° -3 |
| Saturday, Oct 17 · low | 31° | 32° +0 | 31° +0 | 30° -2 | 34° +3 |
Each forecaster is shown as it stood at the start of the period (7-8 AM for highs, 7-8 PM for lows). Small number = forecast minus observed.
Method
Our forecast is a statistical correction of the models, trained on this station (forecasters call this model output statistics, MOS): the four global models are averaged, then a separate straight-line correction for each target and lead day, fitted on roughly 900 days of station history, adjusts that average using the factors listed in "Why ours is…" above (cloud, sunshine, wind, dew point, instability, clear and calm nights, model disagreement, season, how warm the models run and their recent error here). The ± is an 80% range sized from the forecast's misses in a fair test (on days set aside for grading), widened when the models disagree. Rain chances come from a probability model on the same guidance plus the National Weather Service forecast discussion from the evening before, read each night by an AI model on the station computer (tested on the past year: 3.4% better over the next two days, mostly in the cool season). The ensembles size the hour-by-hour range and feed the 6-hour nowcast; the HRRR and upper-air fields are shown for context and archived to train the next version. More on How it works.