Area Forecast Discussion
Issued by NWS Charleston, WV-- Highlight Changed Discussion --
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FXUS61 KRLX 220920
Area Forecast Discussion
National Weather Service Charleston WV
520 AM EDT THU SEP 22 2016
Dry weather is expected with temperatures running much above normal
through the work week as upper ridging remains overhead. Dry cold
front late Saturday.
.NEAR TERM /THROUGH TONIGHT/...
As of 435 AM Thursday...
Another cool early morning for our area as high pressure keeps a
firm grip on the weather pattern. No real changes with this
package save a few cosmetic tweaks here and there to keep
forecast temps in line with observed trends. Guidance remains
slightly warm for overnight mins and a little cool for afternoon
maxes, so adjusted accordingly through the day and into tonight.
Continuing to observe more persistent cirrus in and near the
mountains that hasn`t dissipated as expected. Near term model
guidance keeps the remnants of Julia near the coastal Carolinas
through the period, so left some clouds in the sky grids through
mid morning as higher moisture pivots around the western periphery
of the closed low. Otherwise, we may see a few cumulus here and
there during peak heating this afternoon, as well as another day
of above normal temps. Leaned heavily once again on a
predominantly persistence forecast with deep mountain and river
valley fog expected again late tonight into tomorrow morning.
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
As of 340 AM Thursday...
Very little change to the short term forecast...with upper ridge
remaining in control. A weak back door cold front will slide
through the region on Saturday night into Sunday...but this front
will be mostly dry with just a slight chance for a shower in the
Northern Mountains. The front will bring little change to
temperatures as we will not see a change in the pattern until well
into the long term portion of the forecast.
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
As of 310 PM Wednesday...
What looked like a promising legit Autumn front for early next
week has been squashed by the global models. The emerging trend
is for the blocking pattern to set up where the upper low/trof is
further west than in previous runs. This keeps the area under the
influence of upper level ridging thru early next week with a
continuation of much above normal temperatures. In fact we may not
be done with 90 degrees across NE KY/S WV.
.AVIATION /09Z THURSDAY THROUGH MONDAY/...
-- Changed Discussion --As of 520 AM Thursday...
Decided to overhaul most of the TAFs based on observational
trends. Sufficient boundary layer moisture has been hard to come
by, particularly at EKN, hence the conspicuous absence of fog this
morning. Attm still have them going IFR around or either side of
10Z but only if temps fall a couple more degrees or some local
enhancement to moisture can be realized, both of which may be
difficult to achieve. Also, eliminated IFR for HTS and have them
only reaching MVFR this morning. PKB has already reached IFR and
expecting CRW/CKB to follow suit in the next hour or so with
better low level moisture for those locations. All sites go VFR by
mid morning with only a few cumulus through the day. Another shot
at deep valley fog again tomorrow morning, although confidence is
low in timing/extent attm.
As of 435 AM Thursday...
Another tricky morning trying to pin down fog timing and extent.
Original thinking had all sites but BKW in IFR conditions, which
is still possible, but much more delayed than what was originally
forecast. Many sites appear to be struggling with too little
moisture despite very favorable overall conditions. Guidance
continues to indicate a slow moistening of the boundary layer
through 09-10Z, so very hesitant to remove IFR vsby/sky conditions,
but may need to revisit in the next hour or so if obs do not
follow guidance. Otherwise, expecting prevalent VFR after 13-14Z
with only a few cumulus possible during the afternoon.
For tonight, another persistence forecast with no significant
changes in the large scale pattern expected.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z FRIDAY...
FORECAST CONFIDENCE: High...except low in fog overnight.
ALTERNATE SCENARIOS: Timing/location of fog forming overnight could
vary. Fog may not materialize as originally thought.
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 09/22/16
UTC 1HRLY 09 10 11 12 13 14 15 16 17 18 19 20
EDT 1HRLY 05 06 07 08 09 10 11 12 13 14 15 16
CRW CONSISTENCY L L L L L H H H H H H M
HTS CONSISTENCY L L L L 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 H H H H H H M
PKB CONSISTENCY M L L L H H H H H H H M
CKB CONSISTENCY M M L L H H H H H H H M
AFTER 06Z FRIDAY...
Dense morning valley fog is possible into the weekend.
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