059 
FXUS61 KRLX 202318
AFDRLX

Area Forecast Discussion
National Weather Service Charleston WV
610 PM EST Fri Jan 20 2017

.SYNOPSIS...
Active weather continues later this weekend as strong closed 
low passes just to the southwest. High pressure brings brief
warm up midweek, before colder air arrives late week.

&&

.NEAR TERM /UNTIL MIDNIGHT TONIGHT/...
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 
tomorrow evening.

&&

.SHORT TERM /MIDNIGHT TONIGHT 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 /00Z FRIDAY THROUGH WEDNESDAY/...
As of 610 PM Friday...

Vfr conditions will prevail early this evening. Big question later 
this evening and overnight becomes the development of valley fog. 
Confident that fog will form in the mountain valleys. Confidence 
becomes less moving westward, as some wind may stir later tonight. 
Expect cumulus clouds on Saturday, starting in the MVFR range but 
quickly lifting into the VFR range. 

FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z SUNDAY...
     
FORECAST CONFIDENCE: High, except medium with fog development 
outside of the mountains.  
   
ALTERNATE SCENARIOS: Timing and location of 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.

UTC 1HRLY       22   23   00   01   02   03   04   05   06   07   08   09
EST 1HRLY       17   18   19   20   21   22   23   00   01   02   03   04
CRW CONSISTENCY  H    H    H    H    H    H    H    H    H    H    L    L
HTS CONSISTENCY  H    H    H    H    H    H    H    H    H    H    L    L
BKW CONSISTENCY  H    H    H    H    H    H    H    H    H    H    L    L
EKN CONSISTENCY  H    H    H    H    H    H    H    M    M    M    L    L
PKB CONSISTENCY  H    L    L    L    L    L    L    L    L    L    L    L
CKB CONSISTENCY  L    L    L    L    L    M    M    L    M    M    L    L

AFTER 00Z SUNDAY...
IFR will be possible again Sunday through Monday with another 
system.

&&

.RLX WATCHES/WARNINGS/ADVISORIES...
WV...None.
OH...None.
KY...None.
VA...None.

&&

$$
SYNOPSIS...TRM/MPK
NEAR TERM...RPY/MPK
SHORT TERM...TRM
LONG TERM...TRM
AVIATION...RPY/MPK