Guide to Interpreting MWFM Forecast Maps

The way to interpret the table entries on the MWFM MidCiX forecasts page is depicted above. MWFM runs as a rapid postprocessor of forecast output from major numerical weather prediction (NWP) centers, propagating mountain waves through their prognostic gridded atmospheres. For MidCiX we are running MWFM forecasts initialized with operational forecast output from three of the major US NWP models, to provide a crude ensemble forecasting capability. These models are:

1. NCEP's Global Forecasting System (GFS), an amalgam of the old Aviation (AVN) and Medium Range Forecast (MRF) global forecasts currently running at T254L64. These forecasts are color coded orange in the MWFM forecast tables (see above). In a new feature for MidCiX, we are running these every 6 hours based on 6 hourly GFS 0,6, 12 and 18Z update cycles, rather than our traditional 12 hourly updates based on the 0 and 12Z update cycles.
2. NCEP's Regional ETA model: in a new feature for MidCiX we are running MWFM based on 6 hourly output from the AWIP3D output of NCEP's ETA model, and reinterpolating these forecasts from their native ~40 km Lambert Conformal longitude-latitude mapping projection to a regular longitude-latitude grid (currently required by the MWFM) with 0.4^ox0.3^o longitude-latitude resolution. These forecasts are color coded green in the MWFM forecast tables (see above).
3. the Navy's Operational Global Atmospheric Prediction System (NOGAPS), DoD's global NWP model run operationally by the Navy at Fleet Numerical at a current operational resolution of T239L30. We are running these NOGAPS-initialized MWFM forecasts every 12 hours based on the 0 and 12Z update cycles from Fleet, and the resultant NOGAPS-MWFM forecasts are color coded pink in the forecast tables.

For MidCiX, we are running two versions of the MWFM in forecast mode: the standard hydrostatic Version 1.1 model (MWFM 1.1) and the newer "next generation" Version 2.1 MWFM (MWFM 2.1) which uses noinhydrostatic ray methods.

Two types of MWFM 1.1 maps are given: a white background JPEG map (shown as the MWFM-1.1 links) and a black background PNG map (shown as the (blk) links). These forecasts are provided for heritage reasons (we have run essentially the same model for over ten years now in NASA missions and its output is well calibrated with accumulated observations and PIREPS) and as simple "quick look" field for assessing the overall situation.

The newer MWFM 2-1 maps are given as white background JPEG maps and are shown as the MWFM 2.1 links. We believe output from the MWFM 2.1 model is the more accurate and should form the basis for forecast planning over output from the MWFM-1.1. The main advantages are reductions in the overactivity problem noted for MWFM-1.1 and better geolocation of wave activity due to ray group propagation methods.

Explanations to follow..........

Explanations to follow..........

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