Weather Tape Wind Web

27 Oct, 2025

Components

The Weather Tape is a grid of arbitrary dimensions, but it should be taller than it is wide. I have chosen 12 rows 8 columns. Each cell is overlain by three layers: temperature, precipitation, and wind. Wind includes a barb and partial hexagon. The barb indicates the direction of and strength of prevailing wind for that day, and the level of completion of the hexagon indicates what level of variation from that is possible. The weather tape can be designed such that all weather barbs can be illustrated off side. A d6 is placed in a given cell as a marker of that days weather.

Temperature varies between extremely hot (XHOT) and extremely cold (XCLD). Approximate corresponding temperature ranges in Celsius have been given as a guide. These may be used to adjudicate attrition, fatigue, suitability &c.

Precipitation is conflated with cloudcover, and ranges from heavy precipitation to clear. Precipitation taking place when temperature is CLD or lower is snow. This scale determines visibility: 6 hexes for clear weather, 2 for heavy precipitation. Fog or smoke are not present on the weather tape and may be included according to the DM's systems, and can reduce visibility further. Note that I use 6 kilometre hexes.

The Wind Web (it looks like a cobweb) is three concentric hexagons with a hollow centre. It is oriented pointy end or flat end up like your world hexes. The outermost cells indicates wind one level stronger than that day's standard. The middle layer indicates that days standard strength, and the innermost one level stronger. A cells location around the hex indicates the direction the wind is blowing from, and a d6 is placed in a cell as a marker of current wind speed and direction. Wind is always reported in the direction it blows from. Thus, a d6 in the outermost top left cell would indicate stronger wind from the northwest.

I have included both a standard and a steady wind webs. The former has a 4in6 possibility of changing each watch, the latter 3in6 and more gradually.

The day is divided into six watches, each of four hours. I have abbreviated them for convenience, and combined the dog watches into one for the purposes of weather reporting.

Wind is divided into seven strengths (See Wind as Cost to Enter Hex), from calm to hurricane. Names are drawn from the Beaufort scale and Roman numerals have been chosen for the barbs to disambiguate them from real wind barbs. Each strength of wind provides a different 'Movement Budget' of 'Movement Points' for sail propelled or oar-propelled vessels. Wind strength additionally determines hexes of drift (differing for large, medium, and small vessels) and the chance of foundering.

Weather-Only Procedure

It is recommended to offload weather to a player familiar with the procedure.

1. Each day, roll a d6 on the weather tape and move according to the result (Illustrated). On the log annotate something like $DATE $WINDDIR $WINDSTRENGTH $VIS $PRECIP $TEMP e.g. '20OCT NW III 4 RA COOL'.
2. Each watch, roll d6 on the wind web: Cross lines corresponding to the number rolled. When the middle watch begins, instead move the wind towards the prevailing wind of that day. If the result fo the d6 would cause you to cross to a direction not permitted by the day's hex barb, ignore it. On the log for that watch, annotate $WATCH $WINDDIR $WINDSTRENGTH, e.g. 'FN W IV'.

Maritime Spotting and Encounters

MARITIME ENCOUNTER per WATCH Table shows the chance of spotting a ship per watch. It has been filled out based on comparing the number of hexes observable and vibes. Harbour areas would be considerably denser, and the open ocean considerably sparser.

Ship Movement

Ships burn 1 to 3 Move Points to enter a new hex. See diagram. I assume the party has multiple ships - so as not to put all the eggs in one basket that might founder or explode - and refer to this as a flotilla. The movement of a flotilla is limited by its least capable ship.

Weather and Maritime Activity Procedure

1. Each day, roll a d6 on the weather tape and move according to the result (Illustrated) and annotate on log.
2. Each watch, roll d6 on the wind web: Cross lines corresponding to the number rolled. When the middle watch begins, instead move the wind towards the prevailing wind of that day. If the result for the d6 would cause you to cross to a direction not permitted by the day's hex barb, ignore it. Annotate on log.
3. DM secretly d100 for spotting-possibility¹ If yes, the DM:
   1. Rolls 1dX for faction (varies by location)
   2. Rolls 1dX for ship type (varies by faction and location)
   3. Determines its bearing and range, ideally by randomly choosing amongst plausible situations.
4. The party moves their flotilla. If and when a contact is encountered, determine initiative: The upwind ship has initiative and may choose whether to move first or second. Movement for the remainder of the watch is alternating, and each turn each flotilla may spend up to 3 Move Points.

Uncertainty

If travelling at night or in fog, become Uncertain: Until the position is fixed by reference to a landmark or the application of navigational expertise, the flotilla is in a superposition.

At Uncertainty I the flotilla may be in the centre, presumed hex or any of its neighbours (7 possibilities) At Uncertainty II the ship may be in its central hex or any of the hexes within 2 hexes of it (19 possibilities).

When this cloud moves over a hazard or encounters the coastline, roll a d8 for Uncertainty I or a d20 for Uncertainty II: The result is the actual location of the flotilla.

Discussion

The power of this is it is directional, and thus allows for a logicl progression of weather states. You can create the usual progression of a cold front or a warm front. I suggest that variation as extreme as seen in the illustrated example shouldn't be present in actual wx tapes.