Amherst, Virginia Weather Forecast Discussion

447
FXUS61 KRNK 191735
AFDRNK
Area Forecast Discussion
National Weather Service Blacksburg VA
135 PM EDT Fri Sep 19 2025
.SYNOPSIS...
High pressure gives way to a backdoor front for Saturday. Though
moisture is limited, cannot rule out a few isolated showers or
storms Saturday afternoon. bring a better chance of showers by
the middle of next week. The backdoor front retreats north
Sunday as a warm front with high pressure overhead. Low pressure
looks to slowly move east from the Midwest into the Ohio Valley
by late next week.
&&
.NEAR TERM /THROUGH SATURDAY/...
As of 110 PM EDT Friday...
Key Messages:
1) Still dry through Sat morning.
2) A few showers/storms possible Sat afternoon.
Quiet weather this afternoon with temperatures surging through
the 80s in the Piedmont, with upper 70s to lower 80s west.
A backdoor front edges south tonight through Saturday. Aside
from a few high clouds, tonight should be mostly clear. Lows
will be close to normal from near 60 east to the lower 50s west.
The front and a piece of upper shortwave energy with increasing
low level lapse rates may trigger a few showers/storm Sat
afternoon. Most model consensus points to the probability of
this occurring being higher over the Alleghanys/southern
Shenandoah Valley, tapering to little or no chance south of U.S.
460.
Enough sunshine to allow temperatures to warm again into the 80s
for most, except some 70s in the higher ridges.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
As of 130 PM EDT Friday...
Key Message:
1) Multiple chance of showers and thunderstorms for the first half
of next week.
This forecast is surprisingly more complex than it has any right to
be. To start off easy, a surface high pressure system is still
expected to wedge into the mountains by this weekend and bring in a
short dip in air temperatures before recovering again. Sunday looks
to be the coolest for this forecast period with highs scratching 80
in southside Virginia. High temps east of the Blue Ridge will rise
back into the mid-80s during the work week. The low temperatures
will generally be in the upper 50s to mid-60s and dew points will
vary between the mid-50s to mid-60s.
The complicated portion is there are two upper level low pressure
systems that could potentially bring multiple round of showers and
thunderstorms to the area. As mentioned in previous discussions, a
cutoff low is still on track to form off the Rockies in Canada and
swoop southeastward into the Great Plains. What is new, however, is
a second low pressure system (confidence low if it will be cut off
as well) forms downstream of the cutoff low but its exact location
is unclear. Confidence is high that this system will be to our north
but how north is the question. Some model guidance suggests a low
level jet could arrive with this system and provide additional
moisture and warm air, so where this low ends up will be of great
interest. Even so, shortwaves directed from the cutoff low will send
disturbances to possibly trigger multiple opportunities for
precipitation. Unfortunately, there is currently not enough
confidence to know for certain of potential impacts. Certainty
should increase by this weekend as additional data pours in.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
As of 131 PM EDT Friday...
Key Message:
1) All eyes on cutoff low, but uncertainty in forecast remains low.
A cutoff low will be the main headline for the forecast for the
middle and latter half of next week. This cutoff low will be
over the central United States by the middle of next week and
slowly make its way eastward. Confidence is growing on this
low`s formation and path into the Mid-Atlantic, but specific
impacts are still very uncertain. A long cold front connected
through the cutoff low stretches from Texas to its south and to
the northern Mid- Atlantic to its east. A surface high pressure
system located in Canada very well could move the zonal portion
of the cold front as a backdoor front and wedge into the
mountains. If this occurs, cooler and stable air will move in
and keep widespread precipitation chances low. Otherwise, there
would be low to modest instability and plenty of wind shear from
the cutoff low to support some organized convection. Granted,
it will be some time until there is confidence in the impact of
the cutoff low to the region.
&&
.AVIATION /17Z FRIDAY THROUGH TUESDAY/...
As of 110 PM EDT Friday...
VFR conditions expected through the TAF period. Exception will
be LIFR fog at LWB 10-13z Sat.  Winds will remain light and
variable.
EXTENDED AVIATION FORECAST...
Should maintain VFR into early next week, aside from any late
night fog at mainly LWB. A few showers/isolated storms Saturday
so cannot rule out sub-VFR mainly toward LWB, but possibly as
far south as BCB/ROA/LYH. Low pressure system may bring us
better chances for showers by the middle of next week with
potential sub-VFR.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...None.
NC...None.
WV...None.
&&
$$
SYNOPSIS...WP
NEAR TERM...WP
SHORT TERM...CG
LONG TERM...CG
AVIATION...WP

NWS RNK Office Area Forecast Discussion