CBM Numerical Weather Prediction and Forecast Models 2

Question 1

Model Output Statistics (MOS) improve upon raw model output primarily by:

Accepted Answer

Applying statistical relationships derived from historical model errors to correct systematic biases

Answer

Running the model at higher resolution in real time

Answer

Replacing numerical forecasts with climatological averages

Answer

Using only the most recent 6-hour model run

Question 2

The High-Resolution Rapid Refresh (HRRR) model is particularly valuable to broadcast meteorologists because it:

Accepted Answer

Runs hourly with 3 km resolution and explicitly resolves convection across the CONUS

Answer

Provides 16-day global forecasts at 3 km resolution

Answer

Is the only model that ingests lightning data

Answer

Offers the longest ensemble forecast period of any operational model

Question 3

What is 'quantitative precipitation forecast (QPF)' as it appears in NWP model output?

Accepted Answer

A numerical estimate of the total liquid-equivalent precipitation over a specified time period

Answer

A qualitative description of precipitation type

Answer

The probability of any measurable precipitation occurring

Answer

The radar-estimated precipitation over the past hour

Question 4

Which of the following statements about the Rapid Refresh (RAP) model is correct?

Accepted Answer

It is a regional hourly-updating model covering North America at approximately 13 km resolution

Answer

It is a global model with 13 km horizontal resolution updated every 3 hours

Answer

It replaces the HRRR for convective-scale forecasting

Answer

It uses a 1 km grid and is the finest-resolution operational model

Question 5

In NWP, 'convective parameterization' schemes are used when model grid spacing is too coarse to:

Accepted Answer

Explicitly resolve individual thunderstorm updrafts and downdrafts

Answer

Compute sea-surface temperatures accurately

Answer

Assimilate satellite radiance data

Answer

Forecast long-wave radiation at the surface

Question 6

A broadcast meteorologist comparing the 00Z GFS run to the 12Z GFS run notices significant differences in the forecast. The best way to convey this to the audience is to:

Accepted Answer

Communicate the range of outcomes and acknowledge forecast uncertainty to viewers

Answer

Always trust the newer 12Z run and not mention uncertainty

Answer

Wait until both runs agree before issuing any forecast

Answer

Only present the run that matches climatology

Question 7

What is the primary advantage of ensemble mean forecasts over a single deterministic model run?

Accepted Answer

The ensemble mean reduces the impact of outlier solutions and generally outperforms a single run on average over many cases

Answer

The ensemble mean is always more accurate than any individual member

Answer

The ensemble mean provides higher spatial resolution than deterministic models

Answer

The ensemble mean eliminates the need for post-processing with MOS