Forecast of the Day • A National Weather Forecasting Contest
Wednesday April 1, 2020
Assignment: Predict the 24 hr minimum temperature (deg F) for Cut Bank, MT (KCTB)
I'm sure that Cut Bank, Montana is a cold place (it's in Glacier County, after all), but a predicted low temperature on Wednesday in the single digits is about 20 F below average, kind of an April Fools Day prank. Let's forecast the Tmin for Cut Bank and see how low it goes.
Question: We've looked at cases where calm winds and clear skies can lead to strong nighttime radiative cooling and low minimum temperatures, but the Wednesday morning NWS forecast for Cut Bank seems opposite to that: "Snow likely, mainly before midnight. Cloudy, with a low around 9. Wind chill values as low as -5. North wind around 15 mph, with gusts as high as 21 mph. Chance of precipitation is 70%. New snow accumulation of 1 to 3 inches possible." So how do you think it's possible that the temperature could get so cold in this case?
What Happened?
Radiative cooling under clear skies and light winds is a way to get the maximum possible nighttime cooling in the current air mass. But what happened in Cut Bank this week was different -- a strong cold front passed through on Tuesday afternoon, bringing in a new, much colder air mass to replace the previous, warmer one. The northerly winds continued all day Wednesday, producing a low temperature of 7 F and a high of only 11 F, all just a result of being in the much colder air. Sometimes both things can happen together -- a cold front comes through and then there is rapid clearing and a strong radiative cooling night, producing even colder temperatures.
| Forecaster | Tmin, deg F (error) | Comment | Day Score |
|---|---|---|---|
| OBSERVED | 7 | Tmin FINAL. | |
| GFS-MOS-00-DAY00 | 7 (0) | 2.8 | |
| 1. kendra15 | 7 (0) | 2.8 | |
| 1. T-Dawg15 | 7 (0) | 2.8 | |
| NAM-MOS-00-DAY00 | 6 (-1) | 2.7 | |
| 3. Jasper15 | 6 (-1) | 2.7 | |
| 4. Abbygale15 | 9 (2) | 2.5 | |
| 4. EmilyS15 | 5 (-2) | 2.5 | |
| 4. Gus15 | 5 (-2) | 2.5 | |
| 4. Joscelyn15 | 9 (2) | 2.5 | |
| 4. Miles15 | 5 (-2) | 2.5 | |
| GFS-MOS-12-DAY02 | 5 (-2) | 2.5 | |
| NAM-MOS-12-DAY02 | 5 (-2) | 2.5 | |
| GFS-MOS-06-DAY02 | 5 (-2) | 2.5 | |
| 9. Alex15 | 4.5 (-2.5) | My best guess | 2.4 |
| GFS-MOS-18-DAY01 | 4 (-3) | 2.4 | |
| 10. Lizzie15 | 4 (-3) | 2.4 | |
| 10. Elizabeth15 | 10 (3) | 2.4 | |
| 10. Shyann15 | 10 (3) | 2.4 | |
| 10. Josh15 | 4 (-3) | I think a reason for it being this cold is that area of the country can experience colder winters because of the geography since you have the huge mountains and valleys which can in a way trap the cold causing it to get stuck there for while. | 2.4 |
| GFS-MOS-00-DAY01 | 4 (-3) | 2.4 | |
| 14. Keith15 | 3.3 (-3.7) | 2.3 | |
| 15. Django15 | 3 (-4) | 2.2 | |
| NAM-MOS-12-DAY01 | 3 (-4) | 2.2 | |
| 15. Anna15 | 3 (-4) | 2.2 | |
| 15. Eavenly15 | 11 (4) | 2.2 | |
| NAM-MOS-00-DAY01 | 3 (-4) | 2.2 | |
| 18. Grace15 | 2 (-5) | 2.1 | |
| 18. Sara15 | 2 (-5) | 2.1 | |
| GFS-MOS-12-DAY01 | 2 (-5) | 2.1 | |
| 18. Leah15 | 2 (-5) | 2.1 | |
| GFS-MOS-18-DAY02 | 2 (-5) | 2.1 | |
| GFS-MOS-06-DAY01 | 1 (-6) | 1.9 | |
| 21. Hailey15 | 0.8 (-6.2) | 1.9 | |
| 22. Mikayleigh15 | 15 (8) | 1.6 | |
| 23. Shelby15 | -3 (-10) | 1.3 | |
| 24. Mathison15 | 20 (13) | 0.9 | |
| 25. Hannah15 | 21 (14) | 0.7 | |
| 26. Autumn15 | 23 (16) | 0.4 | |
| CLIMATE | 25.2 (18.2) | NCDC Climate Normals, 1981-2010 | 0.1 |
| 27. Gianni15 | 45 (38) | 0 |