Severe Thunderstorm Warning 172, NWS Topeka, KS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TOPEKA KS
1243 PM CDT MON SEP 7 2015

...Update to aviation forecast discussion...

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 213 AM CDT MON SEP 7 2015

An axis of isentropic lift stretches from central to far
northeast KS on the 305-310 K surfaces and is responsible for the
scattered storms currently moving through portions of eastern KS.
This isentropic lift is forecast to continue through the morning
hours and gradually move eastward as the low level jet veers.
Given these storms are elevated and the instability aloft is
marginal do not expect any severe wind or hail. The boundary layer
inversion appears rather shallow therefore could not rule out an
isolated wind gust reaching the surface. Several models are
forecasting a few perturbations within the flow aloft that may
track over the area during the day today. This activity should
stay scattered in coverage and remain closer to the KS/NE state
line given the better forcing will likely be further north. If any
surface based storms can develop late this afternoon and evening
there is a chance it could be strong to severe. The MUCape could
reach as high as 3000 j/kg while deep layer shear approaches 35
kts, which could support an isolated severe storm. One focus for
this developed could be the synoptic front that will still reside
across the forecast area. All of this could be negatively affected
by extensive cloud cover and or any lingering precip. Forecast
high temperatures will also depend on this and as of now will
range from upper 80s to the mid 90s mainly in central KS. Later
tonight isentropic lift will likely increase ahead of the main
deepening trough. This isentropic lift appears to be stronger and
the instability higher over over southern NE. So the best chance
for storms should be near the state line and then into portions of
northeast KS as the low level jet veers. Heavy rainfall will also
be a threat with pwats approaching 2 inches this evening and
overnight. The isentropic lift and moisture transport could stay
focused over the same area for a good portion of the night,
although there is a chance that the bulk of the overnight precip
remains across NE.

.LONG TERM...(Tuesday THROUGH Sunday)
ISSUED AT 213 AM CDT MON SEP 7 2015

Quite a bit of variance in the models in the amount of instability
available on Tuesday for storms. Think the GFS/EC which are lower
are more sensible given day will likely be influenced by
cloudiness from overnight storms in the area. Relatively good
agreement that better rain chances come in the afternoon through
the evening hours, moving through the southeast in this timeframe
with lift from the stronger wave and passage of the surface front.
0-6km bulk shear still on the marginal end around 25-35kts with
better shear north of the area. PW values still well above normal
in the 2 inch range, so main hazards still look to be heavy
rainfall, wind gusts and possibly hail in the stronger updrafts.
Temperatures tricky to forecast given Tuesday as a transition
period, but have low 80s north to low/mid 80s south before storms
and front push southward through the day. Lows fall into the lower
to mid 60s as front comes through quickly and brings in drier
continental air behind.

Conditions dry out for Wednesday as the surface high moves
through, with a weak shortwave passing on Thursday bringing
another low end chance for precipitation and a reinforcing shot
of cooler air for Friday and Saturday with highs forecast in the
70s. Return flow around the surface high brings highs back to the
80s on Sunday. Kept some low chances for precip on Saturday as
some guidance continues to indicate a passing wave through that
timeframe.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z Tuesday AFTERNOON)
ISSUED AT 1236 PM CDT MON SEP 7 2015

Currently a weak shortwave is still making its way over northeast
KS. A few showers remain to the South of the terminals, but trends
continue in weakening and decreasing coverage. Improvements in
CIGS at KTOP should continue over the next couple hours. The
balance of the afternoon and early evening look VFR at this point.
Confidence into the evening decreases with storm chances once
again in the overall picture. However, coverage and exact timing
are not certain. Have included VCTS in the overnight period again
as the Low Level Jet will still be influencing the terminals and
low- level boundary will still be a factor in the overall forecast
likely through the entire period.

&&

.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

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

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TOPEKA KS
107 PM CDT MON SEP 7 2015

KSZ008>012-020>024-026-034>040-054>056-058-059-081815-
REPUBLIC-WASHINGTON-MARSHALL-NEMAHA-BROWN-CLOUD-CLAY-RILEY-
POTTAWATOMIE-JACKSON-JEFFERSON-OTTAWA-DICKINSON-GEARY-MORRIS-
WABAUNSEE-SHAWNEE-DOUGLAS-LYON-OSAGE-FRANKLIN-COFFEY-ANDERSON-
107 PM CDT MON SEP 7 2015

THIS HAZARDOUS WEATHER OUTLOOK IS FOR EAST CENTRAL...NORTH
CENTRAL AND NORTHEAST KANSAS.

.DAY ONE...THIS AFTERNOON AND TONIGHT.

SCATTERED THUNDERSTORMS WILL LINGER SOUTH OF INTERSTATE 70
THROUGH THE AFTERNOON HOURS AND ARE NOT EXPECTED TO BE SEVERE.

FURTHER NORTH NEAR THE NEBRASKA BIRDER THUNDERSTORMS MAY
REDEVELOP LATER THIS AFTERNOON...AND A FEW OF THESE STORMS COULD
BE STRONG TO SEVERE WITH DAMAGING WIND GUSTS AND LOCALLY HEAVY
RAINFALL THE PRIMARY HAZARDS. AN ISOLATED TORNADO IS ALSO POSSIBLE
NORTH OF A CONCORDIA TO HORTON LINE.

ADDITIONAL OVERNIGHT THUNDERSTORMS MAY BRING LOCALLY HEAVY
RAINFALL...MAINLY TO AREAS NORTH OF INTERSTATE 70.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY.

THUNDERSTORM CHANCES CONTINUE TUESDAY INTO TUESDAY EVENING AS THE
SURFACE FRONT AND UPPER SYSTEM MOVE THROUGH THE AREA. A FEW OF
THESE STORMS COULD BE STRONG TO SEVERE.  LOCALLY HEAVY RAINFALL
WILL ALSO CONTINUE TO BE A HAZARD.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED NORTH OF A CONCORDIA TO HORTON
LINE LATER THIS AFTERNOON AND EVENING.

&&

MORE DETAILED INFORMATION CAN BE ACCESSED AT...
HTTP://WWW.WEATHER.GOV/TOP/SITREP