CIP and FIP
The Current Icing Product (CIP) combines sensor and Numerical
Weather Prediction model output to provide an hourly,
three-dimensional diagnosis of the icing environment. The Forecast
Icing Product is similar to CIP except that it does not include the
sensor inputs. CIP/FIP outputs include calibrated icing probability,
icing severity, and potential for SLD (supercooled large drop -
includes freezing drizzle and freezing rain). Probabilities do not
reach 100% because the data available to diagnose icing do not allow
for a diagnosis with absolute certainty at any given location in
space. Icing severity encompasses five categories (none, trace,
light, moderate, and heavy). SLD potential appears as a red
hatching.
CIP/FIP are output on a grid with pixels every 20 km in the
horizontal and 1000 feet in the vertical. FIP Forecasts extend
hourly to 12 h. ADDS displays every other level except on the Flight
Path Tool that provides access to all levels. To retrieve a graphic
on the ADDS icing
page,simply alter the desired variable using the left-side
pull-down menu then select the desired altitude from a separate
pull-down menu to the right of the product list. The requested
graphic should appear as an image embedded directly in the icing
page. Besides the individual levels, you can select a composite,
maximum value of all altitudes, labeled "max." This image provides a
quick overview of the regional icing threat.
On the icing probability graphics (sample shown in Fig.1), the
scale is from 0 to 85%, using cool to warm colors with warmer colors
indicating higher icing likelihood. On icing severity graphics
(sample shown in Fig. 2), the scale is from trace (very light blue)
to heavy (dark blue). SLD icing threat is indicated by overlaid red
hatching (sample shown in Fig. 3). Icing severity can also be
"masked" to show points where the icing probability is greater than
25% or 50%. Either of these options use a gray color to mask the
severity pixels where icing probability is less than the threshold
value (sample shown in Fig. 4) but still exists.
Pilot reports (PIREPs) of icing are overlaid on the single-level
graphics (legend found at the bottom of each graphic) if within 1000
ft vertically and 75 min temporally. On the composite graphic,
PIREPs for all altitudes are shown (except negative icing reports,
which are omitted for the sake of clarity).
Those interested in learning more details of the science used to
create CIP are invited to read the following paper which is
available free-of-charge to the public at
http://journals.ametsoc.org/doi/pdf/10.1175/JAM2246.1:
- Bernstein, B.C., F. McDonough, M.K. Politovich, B.G. Brown,
T.P. Ratvasky, D.R. Miller, C.A. Wolff and G. Cunning, 2005:
Current Icing Potential (CIP): Algorithm description and comparison
with aircraft observations. J. Appl. Meteor., 44,
969-986.
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Fig.1: Icing probability

Fig.2: Icing severity

Fig.3: Severity with SLD
overlay 
Fig.4: Masked icing severity
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