Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Charleston WV
649 am EDT Sat Jul 30 2016
an upper level trof will keep the weather unsettled into early
next week. Upper level ridging may bring a warmer, quieter
interlude during the middle of next week.
Near term /through tonight/...
645 am update...
Forecast on track with scattered showers across the middle Ohio
Valley early this morning.
The very warm and muggy Summer air remains in place this period,
as an upper level trough and weak surface low pressure center
reside just to the north and west of the forecast area. This
spells the chance for showers and thunderstorms, most likely in
the afternoon heating, but further modulated by smaller embedded
ripples in the flow.
One such feature moving through the middle Ohio Valley early this
morning may refire showers and thunderstorms over the northern WV
mountains this afternoon. Another may arrive from the west late
today and move across this evening. Sped up the timing suggested
by the NAM on this one by two to three hours.
Areas of low clouds and fog will continue to be common during the
overnight and early morning hours.
Temperatures on or close to previous forecast and latest guidance
except a bit lower than the higher mav on highs today.
Short term /Sunday through Tuesday/...
models showing moisture remaining over the region on Sunday. Showers
and thunderstorms are once again possible...more likely in the
afternoon and evening hours. By Monday...NAM shows a wave moving
over the area that other models are not showing. Some of the other
models are showing a vorticity lobe however...which does lend a
bit a credence to the NAM solution. Will hedge the forecast a bit
just in case...but not fully buy the NAM solution. By
Tuesday...NAM still showing moisture over the region while other
models are dry. Since current forecast is dry...will stay with
consistency for now.
Long term /Tuesday night through Friday/...
overall...drier to start next week...with high pressure...surface
and aloft in control. Upper ridge strengthens across the area mid
week...with increasing temperatures. Looking at generally diurnal
showers and thunderstorms...mostly in the mountains...although a
slight chance cannot be completely ruled out elsewhere. Frontal
boundary approaches late in the extended...but at this point...lots
of uncertainty in timing.
Aviation /12z Saturday through Wednesday/...
fog either dissipated or never really formed in the first place,
depending upon location. Pockets of IFR stratus did form, and
will again take much of the morning to mix into an MVFR stratocu
deck and then mix out into a VFR cu field for the afternoon.
Showers and thunderstorms remain possible this period, most likely
across the northern WV mountians this afternoon, and across the
middle Ohio Valley this afternoon into this evening.
Fog and stratus are likely to form again tonight, but confidence
remains low to medium, as showers and thunderstorms will remain
possible tonight as well.
Flow surface and aloft will be mainly light southwest.
Confidence and alternate scenarios...
Forecast confidence and alternate scenarios through 12z Sunday...
Forecast confidence: medium.
Alternate scenarios: timing of lifting and break up of stratus and
stratocu may vary this morning. A thunderstorm may directly
impact an Airport with IFR conditions this afternoon and evening. The
fog and low cloud forecast for overnight tonight into Sunday
morning depends upon higher clouds and precipitation.
Experimental table of flight category objectively shows consistency
of weather forecast office 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 l l l M M M h h h h h h
heights consistency l l l M M M h h h h h h
bkw consistency M M M M h h h h h h h h
ekn consistency l l l l M h h h h h h h
pkb consistency l l l l l M h h h h h h
ckb consistency l l l M M M h h h h h h
After 12z Sunday...
IFR conditions in low clouds and/or fog during the overnight into
the morning hours each day, and briefly in showers and
thunderstorms each afternoon and evening, but mainly Monday, which
would in turn make Tuesday morning a better candidate for fog and