-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KRNK 250550
AFDRNK

Area Forecast Discussion
National Weather Service Blacksburg VA
150 AM EDT Mon Sep 25 2017

.SYNOPSIS...
High pressure over the eastern United States will continue to
bring mainly warm and dry weather to the region through midweek,
while Hurricane Maria stays just off the east coast. A dry cold
front will move through the Appalachians and mid Atlantic
region on Thursday, with much cooler weather for the end of the
workweek into next weekend.

&&

.NEAR TERM /THROUGH TODAY/...
As of 840 PM EDT Sunday...

Evening soundings show lingering very dry air aloft beneath a
swath of high level moisture associated with cirrus fanning out
to the northwest of Maria. This trend looks to continue
overnight with periodic thicker canopy making for intervals of
partly cloudy skies espcly south. Otherwise should be mainly
clear through high clouds, while fog coverage likely inhibited
via drying from earlier and lingering rather low dewpoints this
evening. Still appears that could see some fog/stratus western
river valleys so leaving in a mention given cooling under light
winds. Since not quite as dry or clear as last night, expect
lows to stay a bit milder with only the valleys dropping well
into the 50s, while overall expecting upper 50s/lower 60s.


Previous discussion as of 230 PM EDT Sunday...

Fair weather pattern continues with high pressure surface and
aloft yielding warm and dry conditions across the region. Expect
cirrus from Maria off the coast to veil the sky over most
locations through tomorrow, but this should not hinder radiational
cooling too much overnight and expect late night valley fog to
develop west of the Blue Ridge. Fair and warm conditions
continue for Monday, but a northeasterly breeze will become
established as we start to feel the influence of Maria moving
northward off the coast.

Lows tonight will generally be in the lower 60s east of the
Ridge with middle 50s to the west along with some cooler
readings in the valleys. Highs Monday will be in the mid/upper
80s east, low/mid 80s west.

&&

.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
As of 310 PM EDT Sunday...

Amplified pattern remains in place with 5h ridge centered from New
England to the Gulf Coast States, while Hurricane Maria shifts north
off the southeast coast, and a trough shifts into the northern
Plains and upper Midwest.

Overall model still keep Maria off the coast with limited impacts
over our area. Still mainly dry but could see a few isolated showers
Tue-Wed in the afternoon. Noticable increase in winds in the east
with 10-15 mph with gusts to 20-25 mph possible by Wednesday.

Temperatures to stay above normal until after Wednesday.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
As of 133 PM EDT Sunday...

Computer models and NHC take Maria east of NC/VA coastline Thursday
as front moves across. Should be fairly dry with trend toward cooler
temperatures this period as 5h trough digs across the area. Stronger
shortwave with another front could trigger a few showers Saturday,
but overall very low chance. After one more warm day Thursday with
highs in the mid to upper 70s west, to mid 80s east, highs should
return to normal Friday-Sunday with mid 60s to lower 70s west,
mainly 70s east.

&&

.AVIATION /06Z MONDAY THROUGH FRIDAY/...
-- Changed Discussion --
As of 145 AM EDT Monday...

With the exception of late night/early morning, which is
somewhat more questionable than usual, looking for VFR
conditions through the TAF valid period at all sites. The cirrus
shield from Hurricane Maria, well off the Atlantic seaboard,
will thicken with time over the forecast area as the hurricane
moves north well off the coast. Soundings and time-height cross
sections of RH suggest limited CU development during the day,
but enough moisture in the 045-060 layer to consider FEW-SCT.
This may be more prevalent in the areas further west with less
cirrus.

The cirrus shield, dry air mass, and light northeast wind flow
around the extreme outer periphery of the hurricane may inhibit
much fog development tonight, but have followed the lead of the
previous forecast to include a brief period of IFR fog at LWB
and MVFR fog at BCB. Have not included elsewhere at this time.

The large circulation around Hurricane Maria will keep a
northeast flow over the area through the period, mainly in the
040-080 range, except at BLF where it will be more in the
090-120 direction. Speeds will be 4-6kts overnight, increasing
to 8-10kts after 14Z, with some low end gusts possible mainly
across the Piedmont.

Extended Aviation Discussion...

Overall persistence forecast early this week as strong high
pressure aloft slowly drifts across areas just to our north. The
upper high will gradually weaken and allow a mainly dry cold
front to move through the region late in the week. Late
night/early morning fog can be expected through the week as
low-level moisture slowly increases in advance of the front. For
the most part, VFR conditions are expected to continue this
week.
-- End Changed Discussion --

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...None.
NC...None.
WV...None.

&&

$$
SYNOPSIS...MBS/WP
NEAR TERM...JH/MBS
SHORT TERM...WP
LONG TERM...WP
AVIATION...MBS/RAB