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542
FXUS62 KRAH 261740
AFDRAH

Area Forecast Discussion
National Weather Service Raleigh NC
140 PM EDT Mon Jun 26 2017

.SYNOPSIS...

A dry cold front will cross the area on Tuesday, followed by high
pressure that will persist over the region through the rest of the
week.

&&

.NEAR TERM /THROUGH TONIGHT/...
As of 1025 AM EDT Monday...

Little adjustment required to the near term forecast.

Deep west-sw flow will continue to maintain a dry air mass over
central NC this afternoon, resulting in mostly sunny skies and warm
temperatures. A near sfc north-northwest flow has advected a less
humid air mass into our region with sfc dewpoints at late morning in
the 50s. These pleasant dewpoints will drop a few more degrees this
afternoon as drier air aloft is mixed towards the surface. Afternoon
high temps solidly in the mid 80s.

Tonight, the approach of a minor upper disturbance will yield patchy
mid-high level cloudiness, primarily after midnight, and mainly west
of highway 1. The presence of the dry sub cloud layer will prohibit
any rain from reaching the surface. Min temps mainly 60-65 degrees
with a few upper 50s in the northern Piedmont.

&&

.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
As of 350 AM EDT Monday...

Our coolest airmass will be in place Tuesday and Tuesday night as
the upper trof axis moves across the area, perhaps accompanied by a
few showers...in the mid morning to early afternoon west...and in
the afternoon to evening in the east. Highs will top out in the
upper 70s north to lower 80s south. With clouds departing early
tomorrow night, mins will radiate down into the mid and upper 50s.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
As of 330 AM Monday...

The flow aloft will become increasingly zonal through the middle of
the week, as a trough initially centered over the Great Lakes lifts
out and a sub-tropical ridge builds over the wrn N. Atlantic. Weakly
perturbed swly flow aloft, on the wrn periphery of the sub-tropical
ridge, will then develop from the MS Valley to the middle Atlantic
region Fri through the weekend, as an upstream trough settles across
the central U.S.

At the surface, Canadian high pressure will crest over the srn
middle Atlantic states (NC/VA) Wed, then drift offshore and into the
central N. Atlantic, where it will remain throughout the forecast
period. Return flow around the high will yield gradually increasing
temperatures and humidity levels, both of which will likely peak Sun-
Mon. Deep dryness, characterized by precipitable water values
initially between one half and three quarters of an inch on Wed,
will ensure dry conditions until at least Fri, after which time the
aforementioned increasing warming and moistening low levels, amidst
a sharpening Appalachian-lee trough, should prove sufficient for at
least scattered convection during the upcoming holiday weekend.

&&

.AVIATION /18Z Monday through Saturday/...
As of 140 PM Monday...

VFR parameters expected across central NC through Tuesday. The
approach of a mid-upper level disturbance will result in patchy mid-
high level cloudiness later tonight through Tuesday. Enough lift may
exists to cause a few showers to develop late Tuesday morning
through Tuesday afternoon. However, occurrence at any one TAF sites
appears minimal at this time, so will omit from forecast. Sfc winds
through Tuesday afternoon will be less than 8 kts. In addition,
ceilings will be at or above 6000 ft.

High pressure will settle in behind the exiting disturbance Tuesday
night into Wednesday, then linger overhead through Thursday night.
As this high exits offshore Friday, the return sly flow will advect
a moist unstable air mass into our region, setting the stage for
scattered afternoon-evening convection, and early morning low clouds
and fog. Thus, the potential for periods of MVFR/IFR parameters will
increase, beginning Friday morning and continuing into the weekend.

&&

.RAH WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

SYNOPSIS...Hartfield
NEAR TERM...WSS
SHORT TERM...mlm
LONG TERM...MWS
AVIATION...WSS