Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Charleston WV
736 PM EDT Tuesday Jul 28 2015
heat continues on Wednesday before strong a cold front arrives
Wednesday night. A dry stretch will follow starting Friday...with
temperatures climbing back above normal over the weekend.
Near term /through Wednesday/...
730 PM update...
forecast on track as convection is beginning to wane for the evening.
increased probability of precipitation into high chance range for the north mountains this
afternoon. Agitated cumulus field with some popcorn rain showers already
popping up. With some low level convergent flow...albeit
weak...amid a juicy airmass and elevated heat source...there will
be no problems with the increased coverage of rain showers/thunderstorms and rain there
today. Elsewhere...extended some chance probability of precipitation via scattered coverage wording
into the c and north lowlands where a weak convergent zone remains.
The hi res models are picking up on this for another area to focus
on for afternoon development. This makes sense given what happened
yesterday with a belt of 700 mb moisture remaining over southeast Ohio and north
WV. Weak flow will mean some ridge top huggers and downpours.
Temperatures will top out in the upper 80s to 90 or 91 in The Lowlands.
There is quite the dry layer above 700 mb...in close proximity of the
mixing height. RUC/hrrr are a bit too aggressive mixing this down
given the very weak flow aloft. Though...feel a couple degree drop
in dewpoints this afternoon is warranted...especially north WV. As
such...think we will come up short of heat advisory criteria over
NE Kentucky/southeast Ohio/S WV.
Rain showers/thunderstorms and rain coverage wanes this evening...leaving just a few
lingering clouds which will give way to another night of dense
River Valley fog.
For Wednesday...expect scattered rain showers/thunderstorms and rain over the mountains much like
today. The old frontal boundary will be overtaken by developing west
flow...so think just an isolated rain showers/thunderstorms and rain in the afternoon in
The Lowlands if even that. Expect quite a bit of cumulus tomorrow
though...which may tamper highs a degree in what otherwise will
be the warmest day of the week. Have highs 90 to 92 in NE Kentucky/southeast
Ohio/S WV lowlands. This in combination with lower 70s dewpoints
will yield heat indices around a 100f. Will continue mention of
possible heat advisory in the severe weather potential statement.
Short term /Wednesday night through Friday/...
cold front pushes through Wednesday night...but will lack some
energy due to the time of day which it moves in...so need to leave
the probability of precipitation at chance. Forcing is minimal...and behind the
front...will be back into a strong surface ridging pattern with
the temperatures and dewpoints slowly creeping upwards again.
Long term /Friday night through Tuesday/...
extended remains dry until the middle of next week when low
chances for probability of precipitation come back into play. Lowland forecast highs range
from the upper 80s to 90 degrees...with the mountains their usual
5-15 degrees off the pace.
Aviation /23z Tuesday through Sunday/...
convection waning for the evening. Dense valley fog likely again
overnight into early Tuesday morning. Ckb will have dense fog unlike
previous nights there...on account of a heavy rain shower earlier
this evening. Other sites may take slightly longer for the fog to
form on account of lack of rain and higher dew point depressions
to start off with. Bkw will have mist overnight on account of
rain twice in the past 24 hours.
Scattered convection Wednesday afternoon will be confined mainly to the
Flow will continue light and variable at the surface and light northwest
Forecast confidence and alternate scenarios through 00z Thursday...
Forecast confidence: medium to high.
Alternate scenarios...timing and intensity of overnight and Wednesday
morning fog may vary.
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 21 22 23 00 01 02 03 04 05 06 07 08
EDT 1hrly 17 18 19 20 21 22 23 00 01 02 03 04
crw consistency h h h h h h h h h h M l
heights 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 h h
ekn consistency h h h h h h h h M M l l
pkb consistency h h h h h h h h M M l l
ckb consistency h h h h h h h h h h M M
After 00z Thursday...
ahead of and along a strong cold front...IFR possible in
showers/storm overnight Wednesday night into Thursday. Low
clouds/fog possible in wake of front in the south and east
Thursday night/early Friday morning.