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Tuesday April 7, 2020

Assignment: Predict the 24 hr maximum temperature (deg F) for Las Vegas-McCarran, NV (KLAS)

An upper level low pressure center is expected to move very slowly eastward in the next couple of days, bringing significant rainfall to Southern California and Nevada. Temperature forecasts for Las Vegas, Nevada are about 10-20 F cooler than average. So let's forecast Tmax for Las Vegas.

Question: Why do you think that the GFS forecasts are cooler than the NAM forecasts?

What Happened?

The early runs of the GFS predicted more rainfall, and so also lower temperatures. But later GFS runs shifted to agree with the NAM, with less precip and the chance for warming into the 60's. The obs show that they had a little light rain in the middle of the day, but then partial clearing, and it was able to warm to 65 F.

Forecasts for Las Vegas-McCarran, NV (KLAS)
Forecaster Tmax, deg F (error) Comment Day Score
OBSERVED 65 Tmax FINAL.
1. Jasper15 65 (0) 3.2
GFS-MOS-00-DAY00 66 (1) 3.0
2. T-Dawg15 66 (1) 3.0
NAM-MOS-00-DAY01 64 (-1) 3.0
GFS-MOS-18-DAY01 63 (-2) 2.7
NAM-MOS-12-DAY02 67 (2) 2.7
PERSISTENCE 68 (3) 2.5
3. kendra15 62 (-3) 2.5
NAM-MOS-00-DAY00 69 (4) 2.3
4. Hailey15 70 (5) 2.1
GFS-MOS-12-DAY01 60 (-5) 2.1
4. Keith15 60 (-5) 2.1
GFS-MOS-06-DAY02 59 (-6) 1.9
6. Leah15 58 (-7) 1.7
GFS-MOS-06-DAY01 56 (-9) 1.2
GFS-MOS-00-DAY01 56 (-9) 1.2
GFS-MOS-12-DAY02 56 (-9) 1.2
CLIMATE 75.6 (10.6) NCDC Climate Normals, 1981-2010 0.9
7. Lizzie15 45 (-20) 0