A spaghetti plot (also known as a spaghetti chart, spaghetti diagram, or spaghetti model) is a method of viewing data to visualize possible flows through systems. Flows depicted in this manner appear like
noodle
Noodles are a type of food made from unleavened dough which is either rolled flat and cut, stretched, or extruded, into long strips or strings. Noodles are a staple food in many cultures and made into a variety of shapes. The most common noo ...
s, hence the coining of this term.
This method of statistics was first used to track routing through factories. Visualizing flow in this manner can reduce inefficiency within the flow of a system. In regards to animal populations and
weather buoy
Weather buoys are instruments which collect weather and ocean data within the world's oceans, as well as aid during emergency response to chemical spills, legal proceedings, and engineering design. Moored buoys have been in use since 1951, whil ...
s drifting through the
ocean
The ocean is the body of salt water that covers approximately 70.8% of Earth. The ocean is conventionally divided into large bodies of water, which are also referred to as ''oceans'' (the Pacific, Atlantic, Indian Ocean, Indian, Southern Ocean ...
, they are drawn to study distribution and migration patterns. Within
meteorology
Meteorology is the scientific study of the Earth's atmosphere and short-term atmospheric phenomena (i.e. weather), with a focus on weather forecasting. It has applications in the military, aviation, energy production, transport, agricultur ...
, these diagrams can help determine confidence in a specific
weather forecast
Weather forecasting or weather prediction is the application of science and technology to predict the conditions of the atmosphere for a given location and time. People have attempted to predict the weather informally for thousands of years an ...
, as well as positions and intensities of
high
High may refer to:
Science and technology
* Height
* High (atmospheric), a high-pressure area
* High (computability), a quality of a Turing degree, in computability theory
* High (tectonics), in geology an area where relative tectonic uplift t ...
and
low pressure
In meteorology, a low-pressure area (LPA), low area or low is a region where the atmospheric pressure is lower than that of surrounding locations. It is the opposite of a high-pressure area. Low-pressure areas are commonly associated with inclem ...
systems. They are composed of deterministic forecasts from
atmospheric model
In atmospheric science, an atmospheric model is a mathematical model constructed around the full set of primitive equations, primitive, Dynamical systems theory, dynamical equations which govern atmospheric motions. It can supplement these equati ...
s or their various ensemble members. Within
medicine
Medicine is the science and Praxis (process), practice of caring for patients, managing the Medical diagnosis, diagnosis, prognosis, Preventive medicine, prevention, therapy, treatment, Palliative care, palliation of their injury or disease, ...
, they can illustrate the effects of drugs on patients during drug trials.
Applications
Biology
Spaghetti diagrams have been used to study why
butterflies
Butterflies are winged insects from the lepidopteran superfamily Papilionoidea, characterized by large, often brightly coloured wings that often fold together when at rest, and a conspicuous, fluttering flight. The oldest butterfly fossi ...
are found where they are, and to see how topographic features (such as mountain ranges) limit their migration and range. Within
mammal
A mammal () is a vertebrate animal of the Class (biology), class Mammalia (). Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three ...
distributions across central
North America
North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...
, these plots have correlated their edges to regions which were glaciated within the previous
ice age
An ice age is a long period of reduction in the temperature of Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers. Earth's climate alternates between ice ages, and g ...
, as well as certain types of vegetation.
Meteorology

Within meteorology, spaghetti diagrams are normally drawn from
ensemble forecasts. A
meteorological
Meteorology is the scientific study of the Earth's atmosphere and short-term atmospheric phenomena (i.e. weather), with a focus on weather forecasting. It has applications in the military, aviation, energy production, transport, agriculture ...
variable e.g.
pressure
Pressure (symbol: ''p'' or ''P'') is the force applied perpendicular to the surface of an object per unit area over which that force is distributed. Gauge pressure (also spelled ''gage'' pressure)The preferred spelling varies by country and eve ...
,
temperature
Temperature is a physical quantity that quantitatively expresses the attribute of hotness or coldness. Temperature is measurement, measured with a thermometer. It reflects the average kinetic energy of the vibrating and colliding atoms making ...
, or
precipitation
In meteorology, precipitation is any product of the condensation of atmospheric water vapor that falls from clouds due to gravitational pull. The main forms of precipitation include drizzle, rain, rain and snow mixed ("sleet" in Commonwe ...
amount is drawn on a chart for a number of slightly different model runs from an ensemble. The model can then be stepped forward in time and the results compared and be used to gauge the amount of uncertainty in the forecast. If there is good agreement and the contours follow a recognizable pattern through the sequence, then the confidence in the forecast can be high. Conversely, if the pattern is chaotic, i.e., resembling a plate of
spaghetti
Spaghetti () is a long, thin, solid, cylindrical pasta.[spaghetti](_blank)
Dictionary.com. Dictionary.com Una ...
, then confidence will be low. Ensemble members will generally diverge over time and spaghetti plots are a quick way to see when this happens.
Spaghetti plots can be a more favorable choice compared to the mean-spread ensemble in determining the intensity of a coming
cyclone
In meteorology, a cyclone () is a large air mass that rotates around a strong center of low atmospheric pressure, counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere as viewed from above (opposite to an ant ...
,
anticyclone
A high-pressure area, high, or anticyclone, is an area near the surface of a planet where the atmospheric pressure is greater than the pressure in the surrounding regions. Highs are middle-scale meteorological features that result from interpl ...
, or upper-level ridge or trough. Because ensemble forecasts naturally diverge as the days progress, the projected locations of meteorological features will spread further apart. A mean-spread diagram will take a mean of the calculated pressure from each spot on the map as calculated by each permutation in the ensemble, thus effectively smoothing out the projected low and making it appear broader in size but weaker in intensity than the ensemble's permutations had actually indicated. It can also depict two features instead of one if the ensemble clustering is around two different solutions.
Various forecast models within
tropical cyclone track forecasting
Tropical cyclone track forecasting involves predicting where a tropical cyclone is going to track over the next 120 hours (or five days), every 6 to 12 hours. The history of tropical cyclone track forecasting has evolved from a single-stati ...
can be plotted on a spaghetti diagram to show confidence in five-day track forecasts. When track models diverge late in the forecast period, the plot takes on the shape of a squashed spider, and can be referred to as such in
National Hurricane Center
The National Hurricane Center (NHC) is the division of the United States' NOAA/National Weather Service responsible for tracking and predicting tropical weather systems between the IERS Reference Meridian, Prime Meridian and the 140th meridian ...
discussions. Within the field of
climatology
Climatology (from Greek , ''klima'', "slope"; and , '' -logia'') or climate science is the scientific study of Earth's climate, typically defined as weather conditions averaged over a period of at least 30 years. Climate concerns the atmospher ...
and
paleotempestology
Paleotempestology is the study of past tropical cyclone activity by means of geological proxies as well as historical documentary records. The term was coined by American meteorologist Kerry Emanuel.
The usual approach in paleotempestology is ...
, spaghetti plots have been used to correlate ground temperature information derived from
borehole
A borehole is a narrow shaft bored in the ground, either vertically or horizontally. A borehole may be constructed for many different purposes, including the extraction of water ( drilled water well and tube well), other liquids (such as petr ...
s across central and eastern Canada. As in other disciplines, spaghetti diagrams can be used to show the motion of objects, such as drifting weather buoys over time.
Business

Spaghetti diagrams were first used to track routing through a factory. Spaghetti plots are a simple tool to visualize movement and transportation. Analyzing flows through systems can determine where time and energy are wasted, and identify where streamlining would be beneficial.
This is true not only with physical travel through a physical place, but also during more abstract processes such as the application of a
mortgage loan
A mortgage loan or simply mortgage (), in civil law (legal system), civil law jurisdictions known also as a hypothec loan, is a loan used either by purchasers of real property to raise funds to buy real estate, or by existing property owners t ...
.
Medicine
Spaghetti plots can be used to track the results of drug trials amongst a number of patients on one individual graph to determine their benefit. They have also been used to correlate
progesterone
Progesterone (; P4) is an endogenous steroid and progestogen sex hormone involved in the menstrual cycle, pregnancy, and embryogenesis of humans and other species. It belongs to a group of steroid hormones called the progestogens and is the ma ...
levels to early pregnancy loss. The half-life of drugs within people's
blood plasma
Blood plasma is a light Amber (color), amber-colored liquid component of blood in which blood cells are absent, but which contains Blood protein, proteins and other constituents of whole blood in Suspension (chemistry), suspension. It makes up ...
, as well as discriminating effects between different populations, can be diagnosed quickly via these diagrams.
References
External links
TIGGE Project at NCAR
{{Visualization
Graphic software in meteorology
Climate and weather statistics
Statistical charts and diagrams
Metaphors referring to spaghetti