Carolina Sky Watcher

Carolina Sky Watcher

  'Forecasting Winter Weather' from page 6

'New Technology' from page 2

with these storms in the past across our region. Some memorable snowstorms were noted in March of 1980, December of 1989, and recently, November of 2000.

Lighter snowfalls (3 inches or less) are more common over eastern North Carolina. Weak low pressure areas, fronts, and upper level disturbances are responsible for producing light snow several times a year across the region. Accumulations are often just a dusting of snow flurries, but about once a year, one of these systems will have the right combination of cold air and moisture, to produce a slushy 1 to 2 inch accumulation.

Sleet and Freezing Rain

Sleet and freezing rain occur when warm, moist air is forced up over a shallow layer of dense, cold air at the surface.  The moisture rises into clouds which begin to precipitate as rain since temperatures within the lower to sub cloud layer are above freezing. As the rain encounters the shallow cold air near the ground, it begins to re-freeze,  forming pellets of frozen rain drops known as sleet. If the cold air mass is very shallow, the rain will remain liquid until reaching the ground, where it then freezes upon contact with objects such as trees, power lines, and bridges.

Ice storms can be extremely

database, the same forecast can
be displayed in a text, digital, graphical or gridded format.  While most people are already quite familiar with the text version of the ZFP, many may not realize that the digital forecast is now being used to create a user-friendly graphical forecast, which provides forecast details in 3 hour time-periods.  This graphical forecast has been available on the Newport NWS  website (www.nws.noaa.gov/er/mhx) for the past few months. 

IFPS will also allow for the development of a new generation of grid-based NWS forecasts.  Since October, the NWS website has been featuring experimental gridded forecasts of maximum and minimum temperature and probability of precipitation for our eastern North Carolina service area.  Future plans include gridded forecasts of winds for the marine community and possible gridded forecasts for aviation and fire weather interests. 

Training of the Newport NWS staff on IFPS use was completed in September.  The plans since completing training were to produce a complete suite of products in IFPS, including the new gridded forecasts by early October, making your Newport NWS office one of the first in the country to transition to this exciting new technology.

by Chris Collins