Area Forecast Discussion
Issued by NWS Charleston, WV-- Highlight Changed Discussion --
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FXUS61 KRLX 210634
Area Forecast Discussion
National Weather Service Charleston WV
134 AM EST Sat Jan 21 2017
Unseasonably warm through the weekend. Strong low passes just to the
south Sunday and Monday. High pressure brings brief warm up midweek,
before colder air arrives late week.
.NEAR TERM /UNTIL 7 AM THIS MORNING/...
As of 730 PM Friday...
With only thin cirrus and light winds, have lowered overnight low
temperatures in many areas.
As of 610 PM Friday...
Cumulus clouds have quickly dissipated this evening and cirrus have
yet to become very thick. Therefore, lowered sky cover this evening.
As of 215 PM Friday...
Warm air has surged into the region behind a warm front that
passed earlier today. Temperatures have already reached the low
60s across the Southern half of the forecast area. Although it
remains mostly cloudy this afternoon, there are some breaks in
the clouds and areas that see any persistent sunshine could
climb into the upper 60s.
Forecast soundings indicate enough low level moisture lingers
tonight for mostly cloudy skies to persist. This will also keep
us quite mild overnight with lows generally in the low 50s to
upper 40s. With the saturated ground, it is possible that we see
some fog develop by early Saturday morning, but this will depend
on cloud cover.
Tomorrow will be another very warm January day as warm air
advection continues. Weak overrunning starts again in the afternoon.
Right now the current thinking is that precipitation will
likely hold off until after 00Z, but have added some slight
chance to low chance PoP across the Southern forecast area
.SHORT TERM /7 AM THIS MORNING THROUGH MONDAY NIGHT/...
As of 345 PM Friday...
Rain Showers may work northeastward into the area, on weak warm
advection, Saturday night. However, rain is much more likely on
Sunday, as an upper level short wave trough crosses.
That trough is basically a warm wave moving northward, ahead of
a much larger short wave trough / closed low approaching from
the west. There may be a relative break in the rain Sunday
night, as the warm wave moves on by. However, the upper level
low barrels across the gulf states, reaching the Carolinas
Monday morning. Surface low pressure forms along the way, and
reaches western VA by Monday morning. The system then turns
north, and heads up the east coast Monday and Monday night.
The eastward trend in the track of the system has ended if not
reversed a bit, so the models are likely now honing in on the
eventual outcome. With the intensity of the system being
maintained, a good one to two inch rain event over much of the
area appears more likely. Some model output is over three inches
over southeast portions of the forecast area. Will continue
mention in HWO.
No major deviations from blended guidance on temperatures. Cold
air aloft associated with this system may now support snow over
the highest terrain as early as Monday evening, and there may be
light accumulations there Monday night. Will continue that
highlight in the HWO as well.
.LONG TERM /TUESDAY THROUGH FRIDAY/...
As of 345 PM Friday...
Big east coast system pulls away on Tuesday, with rain and high
elevation snow showers ending, lastly in the mountains.
There is a brief opportunity for a return of warm weather
Wednesday, before a new cold front arrives Wednesday night. That
front heralds a pattern change back to colder weather, as a
long wave trough migrates eastward to the eastern U.S. Upslope
flow, weak disturbances along the cyclonic shear side of the
upper level flow, and lake trajectories, will lead to scattered
rain showers eventually transitioning over the snow showers over
lower and lower terrain.
Temperatures close to guidance blends with the cool down after
the Wednesday spike.
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
-- Changed Discussion --06Z Saturday thru 06Z Sunday...
As of 105 AM Saturday...
A deep moist southerly flow will prevail this period with
abundant clouds. An upper disturbance will pass mostly south
and east of the area this afternoon and evening, with another
upper disturbance approaching from the southwest by Sunday
Clouds across the north at 06Z are thin enough with near calm
winds and wet ground to bring IFR river valley fog, affecting
PKB, CKB ,EKN, with IFR fog possible later at CRW. Otherwise,
ceilings overnight will be VFR ranging from 5000 to 250000
feet. The fog will tend to lessen toward dawn as boundary layer
winds bring to stir. VFR ceilings around 4000 feet will be the
rule by 16Z, with widely scattered VFR showers mainly over the
southern mountains this afternoon and evening with the first
upper disturbance. After 00Z ceilings mainly aoa 7000 feet with
possible IFR fog at EKN by 08Z. Otherwise, expect scattered
showers into the southern coal fields by 12Z Sunday.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z SUNDAY...
FORECAST CONFIDENCE: Low to medium with fog overnight.
ALTERNATE SCENARIOS: Timing and location of river valley fog
overnight could vary.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE SAT 01/21/17
UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
EST 1HRLY 01 02 03 04 05 06 07 08 09 10 11 12
CRW CONSISTENCY H M M M M M H H H H M L
HTS CONSISTENCY H H H H H H H H H H M L
BKW CONSISTENCY H H H H H H H H H H M L
EKN CONSISTENCY L L L L L L L L M M M L
PKB CONSISTENCY M L L L M L H H H H M L
CKB CONSISTENCY M L L L L L L M H H M L
AFTER 06Z SUNDAY...
IFR will be possible again Sunday through Monday with another
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