Area Forecast Discussion
Issued by NWS Charleston, WV-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
FXUS61 KRLX 201050
Area Forecast Discussion
National Weather Service Charleston WV
650 AM EDT Thu Apr 20 2017
Airmass thunderstorms expected today with more widespread storms
late tonight as a cold front crosses the region. Front lifts
back north late Friday night/Saturday.
.NEAR TERM /THROUGH TONIGHT/...
As of 350 AM Thursday...
Going to be another hot and fairly muggy day for April standards
across most of the area today. A stationary boundary is
currently located just west of Elkins and extends to the WSW
through Central West Virginia. With max heating today we could
see a few showers and thunderstorms develop in the vicinity of
the boundary, but dry air aloft will be a limiting factor and
not expecting widespread until later tonight.
Guidance is a fairly good agreement, showing a cold front
pushing into the Ohio Valley close to midnight. This front will
pack quite a punch to our west where it will pass around max
heating this afternoon. However, a line of thunderstorms will
persist into this evening and will continue to weaken as it
heads eastward with the loss of diurnal heating. By the time it
reaches the Ohio Valley, CAPE values will be in the range of 500
to 800 J/Kg, but 0-6 km shear will still be around 35 to 40
knots, so some damaging winds may be possible. SPC currently
keeps us in a marginal risk simply due to the uncertainty with
how quickly these storms weaken tonight. The best chance to see
severe weather in our area will be across Southeast Ohio and we
have highlighted this in the HWO. Elsewhere however, we can just
expect mostly heavy rain showers and some thunderstorms through
the early morning hours on Friday with the front clearing the
area after 12Z Friday.
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
As of 400 AM Thursday...
The cold front will moves south southeast taking all pcpn to the
eastern mountains and extreme southern coalfields of WV by Friday
12Z. Kept likely PoPs over the northwest slopes and eastern mountain
per slower ECMWF model Friday morning. The front stalls south of the
area and then returns north as a warm front to bring unstable
conditions and showers or storms through the weekend.
A sfc low pressure system then moves from west to east along KY and
VA to enhance lifting over southern WV Sunday. With available low
level moisture, pwats around 1.4 inches showers and storms will be
possible mainly across extreme southern WV and extreme
southwest VA into early Sunday.
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
As of 400 AM Thursday...
Drier and cool air filters from the north northeast to bring
pleasant conditions by the end of the weekend.
Shortwave trough aloft lifts northeastward into the Great Lakes
Tuesday night, so the rain from that system should stay north. Broad
upper level trough sets up over the intermountain west, with a new
baroclinic zone developing northwest of our CWA. Should stay dry
until a surface low departs from the southern plains, while we get
back into a warming trend.
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
-- Changed Discussion --As of 645 AM Thursday...
Not too many changes since my previous discussion 5 hours ago so
have left mostly as is.
A stationary front will remain over the area through the day
today and a cold front starts to push in from the NW tonight.
There will be few showers today and isolated thunderstorms are
looking more likely, especially across the Eastern Half of West
Virginia. Still appears like we will see more widespread shower
and storm activity with the cold front late tonight. Mostly VFR
conditions through the day today, but can`t rule out some
restrictions with stray showers storms this afternoon.
Also, depending on the timing of the cold front tonight, we will
likely start to see MVFR to possibly brief IFR conditions
arriving into the Ohio Valley by midnight. The storms will
weaken as they head east early Friday morning. Possibly may see
low stratus after the front passes as well.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z FRIDAY...
FORECAST CONFIDENCE: Medium.
ALTERNATE SCENARIOS: Brief MVFR and maybe IFR could occur with
rain showers or possibly thunderstorms this afternoon.
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 10 11 12 13 14 15 16 17 18 19 20 21
EDT 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
CRW CONSISTENCY H H H H H H H H H H M M
HTS CONSISTENCY H H H H H H H H H H M M
BKW CONSISTENCY H H H H H H H H H H M M
EKN CONSISTENCY H H H H H H H H H H M M
PKB CONSISTENCY H H H H H H H H H H M M
CKB CONSISTENCY H H H H H H H H H H M M
AFTER 12Z FRIDAY...
IFR possible Saturday into Sunday with another wave of low
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