Area Forecast Discussion
Issued by NWS Charleston, WV-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
FXUS61 KRLX 290739
Area Forecast Discussion
National Weather Service Charleston WV
339 AM EDT FRI JUL 29 2016
Upper level troughiness will keep the weather somewhat unsettled
into early next week. Upper level ridging may bring a warmer,
quieter interlude during the middle of next week.
.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --Widespread low clouds and fog are likely to take most if not all
of the morning to burn off and lift out.
Next in a series of upper level short wave troughs crosses
southern portions of the area midday and this afternoon. Hence
PoPs increase from the southwest.
This short wave is out ahead of main trough axis, which itself
approaches the forecast area late today and tonight. Forcing
associated with it enters the middle Ohio Valley toward this
evening, so associated convection approaching late today will
tend to diminish over the middle Ohio Valley as the sun sets.
Nonetheless, will carry a chance overnight as the feature
generates some low level convergence as it crosses.
PW values approaching two inches with these features, and overall
light deep layer flow, support locally heavy downpours. With the
light flow, and modest heating today, the threat for severe
weather is limited.
Temperatures close to inherited forecast and current guidance,
except used the MET to lower highs south a bit, based on the short
wave trough further limiting opportunity for sunshine and heating
-- End Changed Discussion --
.SHORT TERM /SATURDAY THROUGH MONDAY/...
Moisture remains over the region through the weekend and into
Monday...although precipitable water comes down slightly. Models
showing several disturbances moving through...but timing and
placement varies by model. Due to these differences...will keep pops
fairly generic with chances of showers and thunderstorms...highest
in the afternoon and evening hours.
.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
Using a combination of WPC and CONSENSus models...indicated building
heights across the region allowing for hot and humid temperatures.
Went with diurnal showers and storms through the term...especially
in the mountains. Ridge will diminish toward end of term as a front
approaches from the west.
.AVIATION /07Z FRIDAY THROUGH TUESDAY/...
Widespread IFR or worse conditions overnight into Friday morning,
although there is variation as to whether the ceilings or the
visibilities are IFR at east through 09-10Z, after which time
dense fog should be more predominate. After sunrise, the fog will
slowly thin out and lift into stratus and then MVFR stratocu. This
will take most or all of Friday morning before a 4-5 kft cu field
predominates for Friday afternoon.
The next in a series of frequent upper level short wave troughs
will combine with whatever daytime heating that can be mustered
after burning off the morning low clouds to produce showers and
thunderstorms in the area Friday afternoon, coverage too low to
mention in the TAFs.
Fog is likely to begin forming again by 06z Saturday.
Light and variable surface flow will continue beneath light
northwest flow aloft, which will become light west late Friday.
CONFIDENCE AND ALTERNATE SCENARIOS...
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z SATURDAY...
FORECAST CONFIDENCE: Medium.
ALTERNATE SCENARIOS: Timing settling in of low stratus and dense
fog may vary a few hours depending on timing exodus of mid deck
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 FRI 07/29/16
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 L L L L L L L L L L M M
HTS CONSISTENCY L L L L L L L L L L M M
BKW CONSISTENCY L L L L L L L L M M M M
EKN CONSISTENCY L L L L L L L L L M M H
PKB CONSISTENCY L L L L L L L L L L M M
CKB CONSISTENCY L L L L L L L L L M M M
AFTER 06Z SATURDAY...
IFR conditions in low clouds and / or fog during the overnight
into the morning hours each day, and briefly in showers and
thunderstorms mainly but not exclusively in the afternoons and