MPASvala Earth test cyclones

information on cyclones in the #mpasvala2026 Earth test simulations

Storms in the simulations will be labeled with an alphanumeric identifier composed of a single letter based on the octant of the sphere in which they first develop and an incrementing number for each successive cyclone formation. Each octant will correspond to a letter from A through H, with A for cyclones developing north of the equator between 90°E and 180°, B for cyclones developing north of the equator between 0° and 90°E, and so on, in counterclockwise order such that alphabetical order progresses from east to west in the northern hemisphere and west to east in the southern hemisphere (H designations south of the equator between 90°E and 180°). For example, the first cyclone to develop east of 90°E in the northern hemisphere (roughly corresponding to the West Pacific) will be assigned the identifier A1. Names will be assigned to storms achieving tropical storm status (winds >= 34 kt) based on the next name in the list the storm would have been given based on the simulation start date of August 2, 2024 — Carlotta in the East Pacific, Debby in the North Atlantic, Asna in the North Indian, Maria in the West Pacific, Pita in the South Pacific, Robyn in the Australian region, Ancha in the Southwest Indian, and Biguá in the South Atlantic.

August run, 48 km uniform

from the May/June 2026 MPAS Earth simulation for August 2, 2024 through September 2

Tropical Storm D1 (Carlotta)

Duration	active at start –
Peak intensity	Winds unknown

exists at simulation start

Hurricane C1 (Debby)

develops from the precursor of the real Hurricane Debby

Tropical Depression D2

this simulation's forecast for the merged Emilia and Fabio precursors

Tropical Depression A1

the first novel tropical cyclone of the simulation