Area Forecast Discussion
Issued by NWS Topeka, KS
FXUS63 KTOP 010911
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TOPEKA KS
411 AM CDT Wed Oct 1 2014
.SHORT TERM...(Today and Tonight)
Issued at 411 AM CDT WED OCT 1 2014
Challenging forecast for today and tonight across eastern KS. Water
vapor and regional radar loops show area of convection moving east
across northeast and east central KS at 3 AM. Another shortwave
trough moving into western KS not having much effect with subsidence
behind aforementioned convection preventing any additional
development so far this morning. Rainfall rates have been around an
inch an hour most places with KTWX dual pol precip estimates doing
pretty good, showing the greatest amounts so far of 1.5" to 2.5" in
a narrow band from Minneapolis to Blue Rapids, northeast into
Some clearing has developed across north central KS this morning
with fog developing over the area. Have added mention of areas of
fog through mid-morning for that area.
Additional rainfall today and tonight a concern with at least a
couple rounds of thunderstorms expected, some of it may be heavy.
Models have not been real consistent in forecasting location of
heaviest rainfall, although the latest runs have come into more
agreement with best rainfall chances this morning and early
afternoon in the far east, then redevelopment favored over east
central KS late this afternoon or evening.
Combination of some heating and lift along possible residual outflow
boundary, expected to be located near east central KS, looks to be
favored area for redevelopment of robust convection after 21Z today.
Besides heavy rainfall, forecast hodographs in this area, especially
from NAM, would appear to be favorable for supercells, with a
tornado or two possible.
Main upper trough then moves eastward onto the High Plains after
midnight. Low-level warm advection will combine with forcing aloft
to produce another area of thunderstorms overnight. Instability
should be elevated above shallow cool air and any severe weather
that might develop later tonight would be mainly hail.
.LONG TERM...(Thursday through Tuesday)
Issued at 411 AM CDT WED OCT 1 2014
Expect convection to be ongoing Thursday morning to start the day.
Surface frontal boundary should extend from northeast corner of
Kansas southeast along the Turnpike to a surface low south of
Wichita Thursday Morning. Longwave trough will move eastward out of
the Rockies and into central sections of Kansas and Oklahoma by late
afternoon. This will progress the front southeast through the day,
however additional thunderstorms are expected to develop along the
front where both shear and instability will be favorable for strong
to severe thunderstorms. Main hazards will be hail and damaging
winds. The front should move out of the CWA by late afternoon on
Thursday and with the upper trough axis moving through in the
evening have kept a small chance of showers and thunderstorms mainly
southeast of Interstate 35. Temperatures Thursday will vary from the
mid to upper 60s behind the front to the mid 70s ahead of the front.
Drier air begins to move into eastern Kansas in the wake of the
front and upper level trough in northwest flow. Energy on the back
side of the upper trough will move through during the day on Friday
as well as and upper level jet maximum around 120 kts. Stronger
winds will mix down from around 850 mb with surface winds increasing
to around 20 kts with gusts around 30 kts through the afternoon
hours. Temperatures around only expected to top out in the upper 50s
to lower 60s. Friday night high pressure will build into central and
eastern Kansas with winds becoming light along with mostly clear
skies temperatures are expected to fall into the mid and upper 30s.
On Sunday an upper level trough will move southeast across the
Central Plains and bring another frontal boundary southeast across
eastern Kansas. No precipitation is expected as there will be little
in the way of moisture. Dry northwest flow will continue into
Tuesday with heights gradually rising Monday through Tuesday
translating into temperatures warming to slightly above seasonal
.AVIATION...(For the 06Z TAFs through 06Z Wednesday Night)
Issued at 1144 PM CDT TUE SEP 30 2014
Main bands of convection expected to affect KMHK through 08z and
the KTOP/KFOE terminals 08z-12z before diminishing with ocnl
mvfr/IFR vsbys in heavier rainfall. Otherwise expect a lull in
precip then through 17z with VFR conditions before more convection
develops in the vcnty from 22z through the end of the terminal fcst.