Area Forecast Discussion
Issued by NWS Raleigh/Durham, NC
FXUS62 KRAH 270717
Area Forecast Discussion
National Weather Service Raleigh NC
317 AM EDT MON JUN 27 2016
High pressure will extend from the Northeast coast southwest through
the Mid-Atlantic tonight, then retreat on Monday. Another
cold front will approach the area late Monday into Tuesday.
.NEAR TERM /OVERNIGHT/...
As of 935 PM Sunday...
Little adjustment required to the near term forecast.
Surface dry air ridge extends west-southwest/east-northeast across
central NC this evening. This feature supported aloft by a ridge
extending from a parent high positioned over the ARKLATEX will
maintain dry weather overnight with seasonable overnight
temperatures. Residual low level moisture should permit areas of
mostly light fog to develop well after midnight. The fog will
quickly burn off within an hour of sunrise.
.SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
As of 320 PM Sunday...
A moistening southwesterly flow will take hold on Monday morning
as the surface high shifts further offshore and a prefrontal
plume of 2 inch PW over the Mississippi River Valley translates
east toward the Appalachians. Convection firing along and ahead of
the front will move east through the Appalachians Monday
afternoon, though the (effective) front will be slow moving given
early front-parallel flow and little upper support other than a
weak disturbance moving out of the southern plains. The bulk of
the higher theta e air and is progged to move into the western
Piedmont Monday evening, and models suggest convection - likely
sub-severe given poor diurnal timing and weak mid-level flow -
will percolate across mainly the northern and western portions of
the Piedmont for the first half of Monday night before finally
shifting toward the Coastal Plain by Tuesday morning. Without
better upper forcing, prefer to keep POPs at 40-60 percent during
the overnight period.
Highs Monday should be about 5 degrees warmer than today and more
climatologically distributed in southwest flow; 87-91. Lows
Monday night in the upper 60s and lower 70s.
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
As of 317 AM Monday...
Cyclonic flow around the broad mid-upr longwave trough over much of
the eastern US will be the general pattern for the long term period.
The surface pattern over the Carolinas will feature a persistent
Piedmont trough that is typical with westerly or west-northwesterly
flow. While the main moisture axis is progged to remain mostly to
our east through the rest of the work week, it appears that there
will be enough moisture lingering over our area, when combined with
the sfc trough and waves embedded in the cyclonic flow aloft, that
20-40 percent pops (highest east) appears warranted...mainly during
the afternoon/evening each day through the period. Rain chances
will then increase next Sunday as the next sfc front approaches and
moves through the area.
With little airmass change expected...look for temps to remain a few
degrees either side of climo through the period, with the main
influence being cloud and precip coverage.
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
As of 840 PM Sunday...
VFR conditions are expected to continue this evening. However, with
mostly clear skies along with the surface ridge axis extending
across the area tonight, it appears that we may see some sub-VFR
conditions develop after midnight. Models indicate a better chance
of fog than stratus tonight. IFR/MVFR visbys will be possible early
Monday morning, mainly at KRDU/KFAY/KRWI, by around 08Z or so
(possibly even LIFR at KRWI). A light southwest wind may limit sub-
VFR conditions at KGSO and KINT. VFR conditions are expected to
return by at least mid morning. Most of Monday will remain dry, with
VFR conditions. However, chances for showers and storms will
increase from NW to SE across the area late Monday, possibly
affecting KGSO/KINT by the end of the TAF period.
Outlook: Convection and the chance of sub-VFR conditions will
increase Monday night through Wednesday as a cold front moves
into the region from the northwest, though unsettled weather may
continue through the end of the week as the front stalls over the