Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC-- Remove Highlighting --
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FXUS62 KRAH 230538
Area Forecast Discussion
National Weather Service Raleigh NC
135 AM EDT SUN OCT 23 2016
High pressure will bring much cooler and drier air to the region through
the weekend. Another cold front is forecast to move through the state
Monday, bringing additional cool and dry air.
.NEAR TERM /TONIGHT/...
As of 930 PM Saturday...
We will continue undercut statistical guidance for lows overnight.
Mixing just above the boundary layer (currently NW at 20-25kt) may
be the only real thing that helps keep the temperatures from falling
solidly into the mid 30s. A few areas may still be able to go to
calm and remain there overnight (cold air drainage into the lower
lying areas - allowing the development of scattered light frost. The
vast majority of our colder Piedmont region should fall into the 35-
40 range keeping the frost threat to a minimum.
We will keep the same wording in the Hazardous Weather Outlook
indicating that a killing frost/freeze is not anticipated with high
confidence (80+ percent). There is a chance (50-60 percent) of
scattered light frost, mainly in the rural low-lying or normally
colder areas. Urban areas of the Piedmont along with the Coastal
Plain should see lows near 40 with a high confidence of no frost.
No advisories will be issued tonight.
.SHORT TERM /SUNDAY AND SUNDAY NIGHT/...
As of 215 PM Saturday...
West-northwesterly flow, 20-30kt at 850mb, ahead of a frontal zone
dropping backdoor into the Mid-Atlantic States, will result in warmer
temps on Sunday. Guidance seems a little too cool based on dry
adiabatic mixing between 925mb and 850mb, though the trend in guidance
has been slowly upward in the past few runs. Expect highs of 68-
72. Not as cold on Sunday night with a light wind, 45-49
.LONG TERM /MONDAY THROUGH SATURDAY/...
As of 225 PM Saturday...
An upper level trough will exit the east coast early this week and a
dry cold font will pass through Monday night leaving central NC on
the front side of an upper level ridge. This will keep temperatures
warm on Monday with highs in the mid 70s but that will quickly
change as surface high pressure builds out of Canada keeping
conditions cool and dry with highs topping out in the 60s on Tuesday
and Wednesday. Northwesterly flow could be breezy at times during
the first couple days of the work week but gusts should top out
around 15-20 mph but not much higher. The coolest night during this
period would be Tuesday night when temperatures drop into the low
40s but frost should not be a threat.
The ridge axis moves through by Thursday morning and a warming trend
will ensue for the end of the week with the main weather feature
being a low pressure system moving through the Great Lakes region
which is accompanied by a deepening upper trough and a surface cold
front that will approach the Carolinas late in the week. Model
solutions differ on the timing and impacts at this time so will
carry slight chance pops starting Thursday through Friday. Highs
during this period will climb back into the low 70s with lows in the
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
-- Changed Discussion --As of 135 AM Saturday...
Rising heights aloft and associated strong subsidence in the wake of
the trough lifting northeast out of the region, while surface high
over the lower MS Valley builds east over the Southeast will support
a continuation dry VFR conditions through the period. Light and
variable winds overnight will become swly during the day on Sunday
as a weak surface trough develops in the lee of the mtns.
Looking Ahead: Dry VFR conditions are expected to dominate through
Wednesday. The next chance for sub-VFR ceilings will arrive Thursday
afternoon as a cold front and attendant showers approach the
area from the west.
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