Area Forecast Discussion
Issued by NWS Topeka, KS

Home | Current Version | Previous Version | Text Only | 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 171137

Area Forecast Discussion
National Weather Service Topeka KS
637 AM CDT Thu May 17 2018

...Update to aviation forecast discussion...

.SHORT TERM...(Today and tonight)
Issued at 243 AM CDT Thu May 17 2018

Early this morning, surface high pressure was centered over IL
and IA, resulting in light southerly winds across the CWA.
Satellite imagery showed a mid-level low spinning over northeast
KS, which was helping to stream some low and mid-level clouds
across northeast and east central KS. The combination of southerly
winds and scattered cloud cover will result in early morning
temperatures only dropping into the upper 50s to low 60s. As a
mid-level ridge progresses eastward across the Central Plains
today, it will gradually push that mid-level low further east into
Missouri. However, this slow progression will result in those
scattered low/mid clouds lingering into the afternoon hours. As a
result, temperatures today may be a couple of degrees cooler over
eastern KS with highs in the low 80s. Further west into north
central KS, expect the combination of mostly sunny skies and light
southeasterly winds to support highs reaching into the mid 80s.

As the mid-level ridge axis moves over the CWA overnight, models
show an embedded shortwave developing along the western edge of
ridge and tracking into north central KS by Friday morning.  While
several models show conditions remaining dry across the western CWA
overnight with precipitation not moving in until Friday morning, a
couple of models show the shortwave potentially being progressive
enough with some isentropic lift present for scattered showers and
thunderstorms to move into north central KS early Friday morning. As
a result, just have some slight chance PoPs in the forecast.  With
increasing cloud cover overnight ahead of this advancing shortwave
along with continued southeasterly winds, expect low temperatures to
range from the upper 50s to low 60s east to west across the CWA.

.LONG TERM...(Friday through Wednesday)
Issued at 243 AM CDT Thu May 17 2018

A few storms could be ongoing across western and central Kansas
early Friday morning, advancing east northeastward with the
warm front and isentropic lift in the central part of the state.
However upper ridging is reinforced through the day, and looks to
put an end to eastward progress by late in the morning. Have kept
some slight chances in the west before noon. Later in the
evening, as the larger scale upper trof moves eastward and the
front strengthens along with the better lift, chances for storms
return and spread eastward along the front into northeast Kansas.
With better wind shear and steeper lapse rates, storms could
bring hail or strong winds as they move through. GFS spreads the
warm sector northward through the day Saturday, with the surface
low in north central kansas. Storms developing during daytime
heating have access to abundant instability, as would storms that
form on the dryline to our west and along the front as it
progresses eastward.  Evolution of how the upper low and surface
features move through eastern Kansas continue to shift from day to
day model guidance, but enough confidence in the general pattern
to indicate Saturday brings the higher threat for severe storms.

Once the front moves through for Sunday, temperatures cool to
nearly normal highs, with a break in rain chances and a slow
warmup on Monday. However flow over the plains is nearly zonal,
and with the western trof once again deepening and moving
eastward, the frontal boundary lifts back over the state for the
mid week next week and the unsettled pattern with frequent
chances for thunder continues. Coolest night of the week looks to
be Sunday night after the front comes through with lows in the
50s and highs in the upper 70s to low 80s, otherwise highs in the
middle 80s and lows in the 60s prevail in the extended forecast.


.AVIATION...(For the 12Z TAFS through 12Z Friday morning)
Issued at 636 AM CDT Thu May 17 2018

For the 12z TAFs, VFR conditions are expected through the period
with easterly winds remaining less than 10kts.




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