South Hill, Virginia 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

696
FXUS66 KSEW 142224
AFDSEW

Area Forecast Discussion
National Weather Service Seattle WA
324 PM PDT Thu Aug 14 2025

.SYNOPSIS...Cool and wet weather is expected late tonight through
Saturday as a strong and moist frontal system pushes through the
northwest. Heavy rain and breezy winds will be the primary impacts
of this system. Conditions will dry out starting Sunday and
through next week more sun and typical summer-like conditions by
the end of next week.

&&

.SHORT TERM /TONIGHT THROUGH SUNDAY/...Relatively calm conditions
today across the area with zonal flow aloft and some patchy low
clouds hanging on from this morning. Temperatures are in the 60s
to low 70s. Temperatures will not warm up much more, with mid 70s
across most of the interior and mid to upper 60s along the coast.
With increasing clouds tonight, lows will be relatively warm, in
the upper 50s to low 60s.

The main feature of the short term will be a frontal system will
will move across the Friday and early Saturday. The system will
have good upper level support from a strengthening upper level
trough currently developing over the Aleutian Islands and into the
Gulf of Alaska. A warm front will move through the area early
Friday morning, with the cold front following behind it Friday
night into Saturday morning. The notable aspect of this system is
the amount of moisture it will be carrying. Precipitable water
values will reach as high as around 1.75", which is almost an inch
above normal and is approaching, if not exceeding, daily record
high values for this time year based on data from UIL. This is
supported by the IVT values in the models, ranging from 500-700
kg/m*s. Long story short, this system will contain a lot of water.
The only main limiting factor is the lack of instability with the
lowest heights and the parent low displaced to the northwest. As a
result, rain rates will likely not be that much of an issue
(except as the main frontal band moves through), but the amount of
rain as a whole is of greater concern. Rain will start out fairly
light and off-and-on through much of Friday morning, with the
main band of heavy rain moving through Friday evening into early
Saturday morning. Through Saturday afternoon, QPF amounts range
from 0.5-1.5" through the interior (lowest in the rain shadow in
the lee of the Olympics from Sequim to Quilcene, highest in
northern interior up to the Canadian border). 2-4" of rain is
expected through the mountains, with peaks up to 5"+ across the
west slopes of the Cascades and North Cascades. This amount of
rainfall will produce hydrologic concerns across the area. These
details are discussed in the hydrology discussion.

In addition to heavy rain, breezy winds will also be a concern
with this system. Southwesterly winds will increase early Friday
morning behind the warm front, peaking Friday afternoon. The
strongest winds will be along the coast and through the northern
interior (north of Everett), with gusts reaching 20 to 30 mph.
Winds decrease Friday night following the cold front passage.
Finally, with the system moving through Friday, temperatures will
be well-below normal with highs in the mid to upper 60s across
much of the area.

Sunday looks to remain mostly cloudy with high temperatures
slightly below average, in the low to mid 70s.

Any near-surface smoke should be pushed out of the area tonight
and the wet and cool conditions should keep any dense smoke to the
immediate vicinity of area fires.

.LONG TERM /MONDAY THROUGH THURSDAY/...Upper level troughing
remains over the Gulf of Alaska through the first half of next
week and mostly zonal flow to weak ridging returns for the second
half of the week. The whole week looks to remain dry, with
morning clouds and perhaps some late-afternoon sun. Sunnier
conditions look more likely Wednesday and beyond. As such,
temperatures will take on a slow warming trend from the low to mid
70s early week to mid to upper 70s by mid week.

62

&&

.AVIATION...Mostly zonal flow aloft this afternoon into Friday
with perhaps a slight shift to the west-southwest from time to
time as an upper level trough prepares to enter the region.
Surface winds generally southwesterly although some locations may
see a wobble to more southerly from time to time. HQM is seeing
more westerly winds and CLM is seeing northerly in their most
recent ob...but that is likely to be more of an impact of their
persistent light and variable winds there and not indicative of a
prevalent direction. Speeds ranging 7-11 kts for most terminals
with 13-18 kts being reported at HQM. Forecast is for winds to
increase as the incoming front approaches between 06-09Z with
speeds generally 10-15 kts and gusts up to 25 kts possible. These
speeds look to persist throughout the remainder of the TAF period.

Widespread VFR conditions in place over W WA this afternoon, even
along the coast where clouds are thickening in advance of the
aforementioned front. Coastal terminals will see MVFR conditions
emerge first around 00Z this late afternoon and then slowly
spreading eastward. Interior terminals, especially those along the
east side of the Sound, will see clouds gradually filling in but
MVFR conditions are not expected to develop until between 03-06Z
tonight. As the front continues to move into the area, conditions
will degrade further as rainfall moves in with widespread MVFR to
IFR cigs expected to be present throughout the remainder of the TAF
period.

KSEA...VFR conditions present but skies will gradually fill in as
front approaches. OVC conditions expected this evening, although
cigs will remain VFR. MVFR conditions emerge overnight as winds
increase around 09Z and cigs will continue to degrade after that.
Wind speeds 8-12 kts are expected. Gusts will be possible on
occasion, but not often enough nor with enough confidence for TAF
inclusion for inclusion in the 00Z TAF. Cigs expected to bottom out
with precip around sunrise and afterward. Vis reductions are
possible, but significant ones are not expected at this time.

18

&&

.MARINE...A strong frontal system will approach the region tonight
into Friday. As it crosses over our area, southerly winds will
become breezy across the coastal waters and the interior waters. A
Small Craft Advisory has been issued for the coastal waters for
the combination of elevated winds and choppy, steep seas. Along
with that, a Small Craft Advisory has been issued for the East
Entrance of the Strait, Puget Sound and Hood Canal, Admiralty
Inlet, and the Northern Interior Waters for elevated winds 20 to
25 kts into Friday evening. Wind gusts may reach up to 35 kts
briefly at times throughout the day on Friday, but are not
expected to be frequent and/or widespread across the waters.

High pressure will briefly build back into the coastal waters on
Sunday before additional weak systems may brush over the area
throughout early next week.

Combined seas building to 6 to 8 feet by Friday morning and
continue throughout the evening. Seas may become choppy/steep
throughout Friday with a dominant period of 7 to 8 seconds. Seas
will gradually decrease to 3 to 5 feet by Monday as high pressure
slowly rebuilds over the waters.

Mazurkiewicz

&&

.HYDROLOGY...As mentioned above, a strong and unseasonably moist
frontal system will move across the area Friday into Saturday,
bringing with it a period of heavy rainfall across the area, with
widespread 2-4" with 5-6" possible over the higher peaks. This
system will bring with it a myriad of hydrologic issues. Very dry
antecedent conditions has left area soil moisture values well
below average, which agrees well with our current drought
conditions. That being said, the soils have hardened, which poses
the risk of significant surface runoff. There is uncertainty in
this, however, as the light rain through the first half of Friday
may be enough to make the soil more permeable and curtail some of
the hydrologic impacts of the system.

As mentioned in the hydrologic outlook, the primary impacts will
include: flooding of urban areas and flat agricultural lands, some
small streams and creeks may flood if enough runoff is created,
and a low (but non-zero) probability of impacts to burn scars,
including flash flooding, debris flows, and other falling debris.

While no rivers are forecast to flood, sharp rises are forecast on
area rivers. These rises will pose a threat to anyone engaging in
recreational activities in area rivers, those in or near the
river valleys, and along trails and forest roads.

Heavy rain should end following the frontal passage early Saturday
morning, but high river flows will linger throughout the day on
Saturday.

62

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...None.
PZ...Small Craft Advisory from 8 AM to 11 PM PDT Friday for Coastal
     Waters From Cape Flattery To James Island 10 To 60 Nm-
     Coastal Waters From Cape Flattery To James Island Out 10 Nm-
     Coastal Waters From James Island To Point Grenville 10 To
     60 Nm-Coastal Waters From James Island To Point Grenville
     Out 10 Nm-Coastal Waters From Point Grenville To Cape
     Shoalwater 10 To 60 Nm-Coastal Waters From Point Grenville
     To Cape Shoalwater Out 10 Nm.

&&

$$