Area Forecast Discussion
Issued by NWS Topeka, KS

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
FXUS63 KTOP 300442

1142 PM CDT Fri May 29 2015

...Update to aviation forecast discussion...

.SHORT TERM...(This Evening through Saturday)
Issued at 301 PM CDT FRI MAY 29 2015

A persistent northward moisture flux into eastern KS has been
ongoing for much of the day, but has very gradually shifted east
this afternoon. Rainfall rates have been light to moderate with a
few heavy pockets, but by shear persistence 12 hour rainfall totals
in the 1-3 inch range have been common south of an Emporia to
Lawrence line. Individual vorticity maxima translating through the
flow throughout the day have produced locally enhanced rain rates,
with the strongest vort max now in far northeast Oklahoma and moving
steadily north northeast. Rain rates with this system appear to be
rather impressive, but the continued slow west-to-east push of drier
air into eastern KS should keep the bulk of this deep moisture plume
just to the east of the forecast area...perhaps having a glancing
influence on Anderson and Franklin counties. Assuming this heavier
rainfall stays east of the area, would be able to cancel the flash
flood watch late this afternoon as overnight activity should be more
scattered and progressive in nature.

Regarding later precip potential, a surface trough was oriented SW
to NE through the Concordia area while a true cold front associated
with the strong upper trough was now surging across south central
Nebraska. Along and immediately behind this front, expect scattered
convection to develop through the evening hours as it moves across
the forecast area...perhaps lasting into the early morning hours in
east central KS. Instability will be quite weak as the front moves
through with less than 1000 J/kg of CAPE. However, given the cool
temperatures aloft with the upper trough moving overhead, could see
a few storms produce small hail. All told, feel that the potential
for severe weather is very low. Also, as previously stated,
convection should be scattered and progressive in nature, so
additional flash flooding is unlikely.

Saturday will start out cloudy, and clouds may persist into the
early afternoon. Expect breezy conditions with cool temperatures in
the middle to upper 60s. Temperatures will be highly dependent upon
persistence of cloud cover, with the current forecast expecting
sunshine by mid afternoon.

.LONG TERM...(Saturday Night through Friday)
Issued at 301 PM CDT FRI MAY 29 2015

Ridge of surface high pressure moves across central and eastern
KS Saturday night with clearing skies and cooler temps. Ridge then
slowly moves off to the east as northwesterly flow aloft sets up
for Sunday through Tuesday. Normally this would be a dry pattern,
and have kept the area mostly dry, but any system that develops
over the High Plains of western Nebraska could drift southeast
into north central KS. So, have occasional low POPs that area into
the first part of the work week. From Wednesday through Friday,
upper ridge moves east and we are in weak flow aloft with the
outside chance of weak shortwaves topping the ridge creating
thunderstorm chances. Best chances will be in the north central
and far northern counties, but confidence for any specific period
that far out is not high. Thus, have low chance POPs west and
north during that time.

As heights build aloft associated with low-level warm air
advection, temperatures will warm through the period. Lows should
warm from the upper 40s to lower 50s Saturday morning to the
middle 60s by mid week. Highs in the 70 to 75 degree range
Saturday will rise into the lower to middle 80s for the middle to
latter part of the work week.


.AVIATION...(For the 06Z TAFs through 06Z Saturday Night)
Issued at 1142 PM CDT FRI MAY 29 2015

For the 06z TAFs, a cold front has already passed through KMHK and
will move through KTOP/KFOE by the early overnight hours, resulting
in winds veering to the north-northwest and becoming gusty at times.
The showers and storms along the front have weakened and become more
scattered, but still cannot rule out a few storms clipping the TAF
sites so have kept only the mention of VCTS. The low-end MVFR
ceilings are lagging well behind the front and the model guidance
has not been handling the timing of these ceilings into the TAF
sites very well. While only low-end MVFR cigs are noted across north
central KS at this time, a few models continue to suggest the
possibility of some periods of IFR ceilings, so have kept a mention
of sct IFR cigs. MVFR cigs will likely persist through much of the
day and possibly through the evening hours as well. Expect winds to
diminish during the afternoon and evening hours as surface high
pressure advances into the area.




SHORT TERM...Barjenbruch
AVIATION...Hennecke is the U.S. government's official web portal to all federal, state and local government web resources and services.