Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
FXUS62 KRAH 011128
Area Forecast Discussion
National Weather Service Raleigh NC
730 AM EDT SAT OCT 1 2016
A weak area of low pressure and associated surface front will drift
east across our region overnight, then push off to the east later
today. Weak high pressure will build over the region this weekend
into early next week.
.NEAR TERM /through tonight/...
As of 635 AM Saturday...
In near term, still quite a bit uncertainty as to the extent of
cloudiness later today and the threat for isolated-scattered
convection later this afternoon.
More immediate concern is the potential for dense fog through 9 AM.
Visibilities per traffic cameras across the region depict conditions
going downhill since 4AM. Low visibility appears to coincide with
the slow moving sfc front, aligned in close proximity to the I-40
corridor. Will have dense fog advisory for this region through 9AM.
Water vapor imagery early this morning still depicts a decent plume
of moisture lifting northward across eastern North Carolina.
Presence of this moisture coupled with afternoon heating and weak
perturbations within the flow aloft should be sufficient to spark a
few showers and isolated thunderstorms, mainly east of I-95.
Some question as to the threat for a shower in vicinity of highway 1.
Models insist that the atmosphere will dry out to the point that
shower development will be prohibited due to lack of
moisture.However, considering that the models are too dry over our
western counties early this morning, would not be surprised if an
isolated shower develops as far west as the highway 1 corridor this
The upper level low over the lower Ohio Valley, driving the moisture
plume across eastern North Carolina, expected to drift northward
today. Drier air aloft rotating around this maturing system will
eventually rotate into most of central NC later today and tonight.
Highs this afternoon will range from near 80 nw to the lower 80s
elsewhere. If clouds are less extensive than forecast (ie more sun),
then could see mid 80s over the far east-se sections of the forecast
Tonight, close proximity of the moisture plume to our eastern border
suggest a continued threat for an isolated shower this evening into
the overnight, mainly east of I-95. Potential for patchy or areas of
fog, mostly along the highway 1 corridor including the triangle
area. Overnight temps mid 50s west where skies will be mostly clear,
to the mid 60s in the far east where clouds may prevail.
.SHORT TERM /SUNDAY AND SUNDAY NIGHT/...
As of 310 AM Saturday...
Expect a continued gradual improvement in weather conditions across
central NC as the upper level low begins to lift off to the
northeast across the eastern Great Lakes. This should shunt the
moisture plume farther east, leading to drier conditions with a
mixture of sun and clouds expected across the east, and mostly sunny
skies west. Will likely see an uptick in mid-high level clouds late
in the day along our western periphery as a disturbance rotating
through the upper level approaches.
Afternoon temps should remain a few degrees above normal, though
fairly uniform, ranging between 80-84 degrees. Expect warmer
overnight temps in the west Sunday night due to a blanket of mid-
high level clouds. Overnight temps in the low-mid 60s areawide.
.LONG TERM /MONDAY THROUGH FRIDAY/...
As of 328 AM Saturday...
The upper level low will move off the Northeast coast by late
Monday. Upper level ridging will build across the East Coast
midweek, while surface high pressure centered over New England
extends into the area. Expect a mainly dry forecast through
Wednesday with near normal highs in the upper 70s.
Uncertainty increases after Wednesday. An upper trough and attendant
cold front will move into the MS Valley Thursday and progress
eastward Friday. Front will likely weaken as much of the main upper
level support remains well north into Canada. Meanwhile, current
guidance differs significantly with respect to the proximity of
Hurricane Matthew to the East Coast due to differences in resolving
the aforementioned trough. Influence of any tropical moisture and
consequent cloud cover and rain chances will be highly track
dependent. Please refer to the National Hurricane Center for the
latest information on Matthew.
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
-- Changed Discussion --As of 730 AM Saturday...
Widespread sub-VFR conditions are highly likely across central NC
through mid morning due to widespread fog and low clouds. Conditions
are expected to improve first in the Triad region shortly as drier
low level air is in close proximity to this area. Aviation
conditions should improve between 14Z and 16Z elsewhere, though
ceilings may remain MVFR in vicinity of KFAY and KRWI through the
Scattered showers and isolated thunderstorms are expected to develop
this afternoon in proximity of KFAY and KRWI with the greatest
threat between 19Z and 23Z. Another round of IFR/LIFR conditions due
to ceilings and possibly visibility (due to fog) appear likely in
vicinity of KRWI, KFAY, and possibly KRDU.
Aviation conditions are expected to improve Sunday through Wednesday
with mainly VFR conditions. The exception will be a chance for MVFR
ceilings and visibility each early morning, with the threat greatest
in proximity of KRWI and KFAY.
-- End Changed Discussion --
Dense Fog Advisory until 9 AM EDT this morning for NCZ021>025-