Area forecast discussion
National Weather Service Topeka Kansas
626 PM CDT Tuesday may 21 2013
Short term...(this evening through wednesday)
issued at 339 PM CDT Tuesday may 21 2013
Upper low remains across the northern plains with energy rotating
around the base moving into north central Nebraska. A strong
shortwave was moving into western Oklahoma at late afternoon. Models
still showing best forcing (q-vector convergence and vorticity
advection) remaining to the south of the forecast area this evening.
Short range high resolution models break out some convection in far
east central Kansas early this evening and will maintain small
precipitation chances for parts of Anderson County this evening.
Cold advection across northern Kansas will continue through the
night with temperatures falling into the upper 40s in north central
Kansas to the middle 50s in east central Kansas.
Clouds will be on the decrease Wednesday morning and expect some
scattered cumulus clouds for much of the afternoon. Cool high
pressure will build into northeast Kansas Wednesday as the upper
trough moves into the Great Lakes during the day. Temperatures will
be coolest across the far north with highs in the 60s with lower 70s
across the south.
Long term...(wednesday night through tuesday)
issued at 339 PM CDT Tuesday may 21 2013
Wednesday night through Thursday night...the upper trough in the upper MS valley
will swing eastward into the Great Lakes as the High Plains upper
ridge shifts eastward into the eastern plains. This will allow for
the dry north to northeasterly flow through 850mb to persist and
keep any significant moisture and/or instability to the south of the
County Warning Area until later Thursday night. This when weak
Theta-E/moisture advection begins across the far west and
southwestern portions of the County Warning Area...so will introduce a slight chance
for thunderstorms at that time. Seasonably cool low temperatures in
the upper 40s and lower 50s Wednesday night will edge up into the low
to middle 50s Thursday night while highs on Thursday top out in the
low to middle 70s.
Friday through Tuesday...the ridging aloft will slowly translate
eastward into the MO and MS valley areas over the weekend into early
next week. This will transition the flow aloft to a more west and
southwesterly direction. This will allow for a Lee side surface
trough/low in the Central High plains to remain anchored through the
period. At the same time...the upper flow will likely direct a
series of weak shortwave troughs out of the main upper trough in the
western Continental U.S. Out into the Central Plains. Moisture return will
continue/remain in place through the period...so the passage any of
the shortwave will have the potential to trigger convection across
the area through the period. This far out it remains very difficult
to pin down the timing and/or areal extent of any convection and
mesoscale features such as outflow boundaries from possible mcs's
each day would only complicate the forecast. Have therefore continued a
broad and general forecast on the precipitation potential with highs generally
in the 80s.
&&
Aviation...(for the 00z tafs through 00z Wednesday evening)
issued at 626 PM CDT Tuesday may 21 2013
Main concern for the tafs is whether some MVFR ceilings between 2 and 3
kft move far enough south to get into the terminals. If it does it
looks like it would be during the middle morning hours. Confidence is
low with rap and NAM relative humidity forecasts just clipping the terminals with the
higher relative humidity...so have kept a VFR forecast at this time.
&&
Top watches/warnings/advisories...none.
&&
$$
Short term...53
long term...63
aviation...wolters
