Area Forecast Discussion
Issued by NWS Charleston, WV

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS61 KRLX 190801
AFDRLX

Area Forecast Discussion
National Weather Service Charleston WV
401 AM EDT Thu Oct 19 2017

.SYNOPSIS...
Dry high pressure with cool mornings and warm afternoons is on
tap through the weekend. A strong cold front and low pressure
system crosses early next week.

&&

.NEAR TERM /THROUGH TONIGHT/...
148 AM Thursday...

Weak S/W trof exits this morning. Southwest wind will pick up
after sunrise and will gradually turn westerly this afternoon.
this wind should keep any fog or frost at bay. Some sheltered
mountain valleys could see patchy fog or frost to start this
morning, but should quickly dissipate after sunrise. Moderating
high pressure over the area will make temperatures a tad warmer
today and tonight.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY NIGHT/...
As of 400 AM Thursday...

High pressure and upper ridging over the area Friday, drift
east of the area this weekend, resulting in warm, and continued
dry weather.

Overnight Sunday night, a northern stream short wave trough
drives a surface cold front toward the middle Ohio Valley,
while southerly flow out of the Gulf of Mexico, enhanced by a
southern stream short wave trough, and surface low pressure
system, feed moisture northward toward / into the area, ahead of
the cold front. All of this conspires to increase the chance
for showers toward dawn Monday.

Central guidance reflects a warming trend in increasing
southerly flow, around the back side of the exiting high.

&&

.LONG TERM /MONDAY THROUGH WEDNESDAY/...
As of 400 AM Thursday...

A northern stream upper level trough lifts out through eastern
Canada quickly on Monday, and the surface cold front it was
driving toward the area washes out as a result.

Models concur on the next northern stream trough being
stronger, and digging into the eastern U.S. Tuesday, to carve
out a full latitude long wave trough over the eastern U.S. by
Wednesday.

Models differ somewhat on the timing of a southern stream short
wave trough that lifts northward ahead of the northern stream
trough. This will affect the timing and track of the associated
surface low pressure wave, and its interaction with the cold
front driven by the digging northern stream feature. This, in
turn, affects the timing and amount of precipitation in the
forecast area. Current blended central guidance suggests
precipitation is most likely Monday night into Tuesday, as the
southern stream feature and then the northern stream cold front
cross.

Models suggest two inches or more are possible given the
contribution of the southern system. The fast, more western
track currently portrayed in the forecast would result in
downsloping ahead of the system, and the typical warm / dry
wedge, in turn resulting in two precipitation maxima, one over
the middle Ohio Valley, and one along the eastern slopes of the
WV mountains.

Central guidance temperatures generally accepted, and reflect a
cooling trend from above to below normal by Wednesday. After a
cold, dry Thursday morning, a slightly milder afternoon should
ensue, as the large trough begins to lift out.

&&

.AVIATION /07Z THURSDAY THROUGH MONDAY/...
06Z Thursday thru 06Z Friday...

As of 137 AM Thursday...

A dry weak trof swings thru early this morning which should
allow for boundary layer mixing. This should keep much, if any,
fog formation at bay. Kept tafs vfr except for KEKN where a
strong low level inversion will keep the boundary layer calm.
VFR conditions will continue through the weekend. Southwest
wind 5 to 10 kts this morning becoming west this afternoon.


FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z FRIDAY...

FORECAST CONFIDENCE: High, except medium for fog.

ALTERNATE SCENARIOS: Dense fog may affect more terminals if
low level winds relax.

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                              THU 10/19/17
UTC 1HRLY       06   07   08   09   10   11   12   13   14   15   16   17
EDT 1HRLY       02   03   04   05   06   07   08   09   10   11   12   13
CRW CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    M
HTS CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    M
BKW CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    M
EKN CONSISTENCY  L    L    L    L    L    L    L    L    H    H    H    M
PKB CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    M
CKB CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    M

AFTER 06Z FRIDAY...
Dense valley fog possible each morning through the weekend, and
in rain at times early next week.

&&

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

&&

$$
SYNOPSIS...JS/TRM
NEAR TERM...JS
SHORT TERM...TRM
LONG TERM...TRM
AVIATION...JS



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.