Area Forecast Discussion
Issued by NWS Topeka, KS
FXUS63 KTOP 190507
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TOPEKA KS
1207 AM CDT Fri Sep 19 2014
...Update to aviation forecast discussion...
.SHORT TERM...(This Evening through Friday)
Issued at 341 PM CDT THU SEP 18 2014
Elevated thunderstorms that persisted across the southwest part of
the CWA into early afternoon before dissipating or moving south into
south central Kansas. Low stratus was breaking up late this
afternoon while still holding firm in the northeast CWA. Baroclinic
zone to the southwest of the CWA begins to slowly move northeast
tonight. Isentropic lift on the 310K surface over the baroclinic
zone at 850 mb may lead to some additional elevated thunderstorms
tonight shortly after midnight in the far eastern counties. An east
to southeast surface flow will continue to maintain dew points in
the low to mid 60s tonight. Forecast soundings show saturation in
the low levels will lead to some patchy to areas of fog once again
as well as formation of low clouds again. Lows tonight will cool
into the low to mid 60s.
Friday clouds should scour out in the morning hours with mostly
sunny skies across the area for the afternoon. Forecast soundings
show that we should mix down from around 850 mb yielding
temperatures in the mid to upper 80s with the warmest readings in
north central Kansas. South winds will increase into the 10 to
20 mph range by afternoon with some higher gusts.
.LONG TERM...(Friday Night through Thursday)
Issued at 341 PM CDT THU SEP 18 2014
The forecast for the weekend periods continues to be focused on
cold front and old tropical remnants making their way into the
Plains. Impacts of the latter on the local area continue to look
minimal, with the upper trough helping keeping it to the south.
The airmass ahead of the front continues to show good instability
but forcing for ascent continues to look rather meager with the
upper trough still well north and only modest cold air advection
in the afternoon and overnight hours. At this point looking like
scattered convection is a good bet in the afternoon and evening.
Could see a few briefly severe storms with initial updrafts, but
weak and fairly unidirectional wind profiles should keep organized
and widespread convection largely in check. Sunday should bring
clearing conditions with any convection remaining in the south
ending in the morning as dry/cold air advection increases. Have
continued to trend highs up with early day insolation Saturday and
the delayed cold air advection into Sunday.
Upper trough off the west coast makes steady east to northeast
progress into the Plains into the middle of the week. Deeper
moisture should be able to return with the weekend front holding up
over the southern High Plains for isolated to scattered type
convection once again for much of the remainder of the forecast
under this slow-moving upper trough. Low levels should be slow to
modify with highs mainly in the 70s next week.
.AVIATION...(For the 06Z TAFs through 06Z Friday Night)
Issued at 1205 AM CDT FRI SEP 19 2014
For the 06z TAFs, a MVFR stratus deck was shifting westward across
the region with clearing skies noted across far eastern Kansas.
These clearing conditions were resulting in areas of patchy fog
developing, with model guidance suggesting that more widespread
coverage of this fog is expected as the stratus deck continues to
clear out of the region. Could see some areas of dense fog possible
across far eastern Kansas, with KTOP/KFOE having the best chances
for visibilities dropping down to around 1 mile for a few hours
before quickly lifting by mid morning. Winds will veer from east to
south through the period with some gusts of 15-20kts possible during
the afternoon hours before diminishing some Friday evening.