Area Forecast Discussion
Issued by NWS Topeka, KS

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
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

000
FXUS63 KTOP 241757
AFDTOP

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TOPEKA KS
1257 PM CDT Sun May 24 2015

.UPDATE...
Issued at 1108 AM CDT SUN MAY 24 2015

Cancelled the flash flood watch in locations which did not
receive the heavy rain in the past 24 hours. Area of showers
should move into east central Kansas by late morning with more
development this afternoon and evening. 12z model QPF from the NAM
and the most recent HRRR keep heavy QPF southeast of us, but there
is enough QPF on saturated ground and areas that are already in
flood to keep flash flood watch going.

&&

...Update to aviation forecast discussion...

.SHORT TERM...(Today and Tonight)
Issued at 323 AM CDT SUN MAY 24 2015

After a round of moderate rain over the area, several mainstream
rivers are rising and forecast to flood in the southeast portions of
the forecast area. Flooding also continues in those counties as
widespread rainfall of 2-4 inches fell across the area.

Precipitation chances in a lull in the early morning hours, before
the next wave in the flow begins to increase precipitation chances
from south to north late this morning into the afternoon hours.
Stronger wave over the Big Bend area of Texas lifts northeastward
and moves into the area for the evening hours, and current thinking
is heavier precipitation would fall late afternoon and into the
evening, and primarily across the eastern portions of the forecast
area.  Another 1-2 inches of rain are forecast in heavier bands,
with locally higher amounts possible. Subsiding air behind the
departing stronger wave could bring rain to an end from south to
north across eastern Kansas by shortly after midnight, and have
tapered off rain chances as such. Kept high temperatures on the cool
side in the lower 70s and went slightly cooler on lows in the 50s.

.LONG TERM...(Monday through Saturday)
Issued at 323 AM CDT SUN MAY 24 2015

By Monday morning the shortwave responsible for today`s rainfall
will be lifting into the upper Midwest leaving southwest flow aloft
in it`s wake. The next shortwave is forecast to eject over the
region late Monday, while another wave passes over the southern
plains. Lapse rates will steepen as en EML spreads eastward over the
area out ahead of the wave. A boundary will be present across
western and central KS possibly accompanied by a weak surface low
pressure. The morning should be relatively quiet with only slight
chances for light rain showers. During the afternoon and evening the
wave will lift over the boundary where isolated to scattered storms
will be possible. Cape should increase significantly during the day
especially if the clouds begin to scatter out. Deep layer shear
looks marginal at best with a weakness in the mid level winds. The
main uncertainty is will the forcing and convergence along the
boundary be enough to initiate storms. Models are also hinting at
deeper mixing in western KS, which could lead to possible dry
punches in central KS. These could also be locations for surface
convergence and storm development once the cap weakens. Either way
if storms do develop there is a chance they could be strong to
severe given the high instability, but will probably not be well
organized. As of now the better chances for precip appear to be
north central KS during the late afternoon and evening hours.

That shortwave will continue to lift northeastward Monday night and
into Tuesday morning. There are some timing issues among the models
therefore have kept some rain chances during the day Tuesday. The
forecast then becomes somewhat tricky to pin down precip timing as
the large scale flow weakens and small shortwaves traverse across
the center of the country. This west to southwest flow will persist
through late week. It is unlikely that we will be dealing with any
widespread heavy rain events similar to this weekend given this
expected pattern. A few more pronounced shortwaves lift out of
the Rockies late week, which could bring better chances for precip
next weekend. An actual front may come through as these waves
progress eastward to allow for a dry period early next week.

&&

.AVIATION...(For the 18Z TAFs through 18Z Monday Afternoon)
Issued at 1245 PM CDT SUN MAY 24 2015

Today and early evening, there are a couple mid-level shortwaves
that will impact the TAF sites. Much of this activity will be in
the late afternoon and early evening with the possibility of some
thunderstorm activity developing which could bring some periods of
low end MVFR CIGS/VIS to the terminals. Outside of this, there are
some spotty areas of light showers right now. Not completely
confident any of these will impact the terminals. Therefore, have
left only VCSH for both the afternoon and then again a chance in
the early morning. Lower confidence on the morning showers. But again,
generally expecting VFR outside of some brief periods with the thunderstorms.

&&

.TOP WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH through Monday morning FOR KSZ026-039-040-
054>056-058-059.

&&

$$

UPDATE...Johnson
SHORT TERM...67
LONG TERM...Sanders
AVIATION...Drake





USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.