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Northern Mariana IslandsSite status

Severe weather analysis

What NCEP’s models forecast, said to be forecasts: an ensemble’s odds and one model’s run. Guidance, not SPC’s outlook and not a warning: for those, see the Briefing and the Live tracker.

Model guidance: what the models forecast

HRRR · Simulated reflectivity · initialized · valid

REFS / HRRR: feeds current

REFS: Feed current; checked .

HRRR: Feed current; checked .

Checked means retrieved, not newly issued. Each graphic retains its issue, observation, initialization or valid time. Site publishing status is separate.

Simulated · a model’s storms, not radar

HRRR forecast from NCEP’s MAG: simulated composite reflectivity (dbz), run 02Z, hour +3, valid Sat 05Z. Simulated by the model, not observed. Its key is in the picture. Opens the picture at full size.
Forecast HRRR run , hour +3, valid . The lower 48, as NCEP’s MAG draws it. Data: NOAA/NCEP.

Simulated composite reflectivity (dBZ)

The strongest echo the model’s storms would give at any height, as a radar would show it. It is where this one run puts storms at this hour, drawn in radar’s colours: a model’s storms, never radar.

One run of one model: it shows where storms could be in this run, not how likely they are, and the next run can put them elsewhere. REFS gives the odds.

Compare REFS and HRRR context
Model, field & forecast hours
Retention & comparison limits

Only rolling current frames and limited previous copies are retained. Complete historical runs are not archived, so two-run comparison is unavailable. Only the published forecast hours are stepped; gaps are explicit. Rainfall uses WPC’s existing forecast, not an unprovided model rainfall field.

REFS (NOMADS) checked · Data: NOAA/NCEP

HRRR pictures (MAG) checked · Data: NOAA/NCEP

Northern Mariana Islands briefing

Not an official warning service. Warnings and watches are the National Weather Service’s, outlooks and reports the Storm Prediction Center’s and the Weather Prediction Center’s (Data: NOAA/NWS, NOAA/SPC, NOAA/WPC). When a warning is issued for you, act on it, and use weather.gov or a NOAA Weather Radio for where you are.