the Winter Weather Forecasts
||0215Z, 0615Z, 1415Z, &
||0700Z & 1900Z
||0300Z, 0745Z, 1500Z, &
About These Products
SOLID LINES indicate the forecaster confidence (low, moderate and high)
that the area to the right of the arrow will receive greater than or equal
to four (4) inches of snowfall in a 12 hour period on the 93s and 94s products,
and six (6) inches of snowfall in a 24 hour period on the 98s product.
The DASHED LINES indicate the forecaster confidence (low, moderate and
high) that the area to the right of the arrow will receive greater than
or equal to one quarter-inch (0.25") of ice accumulation on all three products.
EXPLANATION OF FORECASTER CONFIDENCE
The WPC has decided to modify its current heavy
snow guidance product in an effort to make it more useful to those making decisions
based on this forecast. This is described in the Public Information Statement.
The confidence levels used can be considered comparable to the probability
of occurrence of the forecasted parameter. For example:
LOW - 20% to 30% chance
of occurrence within the outlined area.
- 31% to 70% chance of occurrence within the outlined area.
HIGH - greater than
70% of occurrence within the outlined area.
At times the forecasters my use only one or
two isolines for the forecast. This simply implies low or low to moderate
confidence in the occurrence of the forecasted
parameter. One should expect the confidence to lower as the forecast is
extended out in time. To gain further insight into this forecast, please
read the Heavy
Snow/Icing Discussion (HSD) that accompanies this graphical product.
If you have any questions or comments about these or any of our products,
we would like to hear from you.
Click here to send mail to the WPC.
November 21, 2001