Special Weather Statement, NWS Topeka, KS

AREA FORECAST DISCUSSION
National Weather Service Topeka KS
1148 PM CDT WED SEP 7 2016

...Update to aviation forecast discussion...

.SHORT TERM...(This Evening through Thursday)
Issued at 314 PM CDT WED SEP 7 2016

Late this afternoon water vapor satellite loop shows southwesterly
flow across the Central Plains. Subtropical moisture continues to
stream northward into eastern Kansas from Newton. Profilers and
satellite show a weak wave moving into northwest Oklahoma at 1930Z
with Newton over southeast Arizona. First wave moved through this
morning with scattered showers through mid morning. Little clearing
occurred across north central Kansas late this morning then has
since filled back in, however there are some breaks showing up in
the latest visible satellite picture at 1930Z. Latest mesoscale
analysis shows MLCAPE ranges from 1500 J/kg to 2000 J/kg with
effective shear of 30 to 40 kts along with moderately steep low
level lapse rates. Lapse rates weaken through the evening hours.
That said with the wave moving out of northwest Oklahoma this
evening and tonight models focus convective development mainly
southeast of a Council Grove to Topeka line tonight. Will continue
with the higher precipitation chances south of I-70 tonight and into
Thursday morning. With the high moisture content in the atmosphere
the potential for locally heavy rainfall exists, especially for
areas along and south of Interstate 35 tonight. A strong to severe
storm or two is possible this evening.

Additional wave will eject northeast into eastern Kansas on
Thursday. There looks like there should be a dry period from late
morning into the afternoon hours. By late afternoon thunderstorm
chances will again increase with the approach of energy aloft toward
northeast Kansas. Models are consistent with bringing the frontal
boundary slowly southeast tonight into north central Kansas and then
stalling it out along I-70 by early afternoon. The front is then
forecast to lift northward in the afternoon as a warm front. Lows
tonight will be mild with lows in the upper 60s to the mid 70s.
Highs on Thursday will be in the mid 80s across the area.

.LONG TERM...(Thursday Night through Wednesday)
Issued at 314 PM CDT WED SEP 7 2016

Thursday Night through Saturday...

Precip chances should continue Thursday night in tropical
moisture plume, with a cluster or MCS of some type moving through
southeast/east central KS where highest forecast POPs and QPF are
located. Heaviest rainfall may be south of turnpike, maybe even
south of I35, but difficult to be that precise that this time.

There may be some showers/thundershowers lingering in parts of the
area into Friday morning, with more concentrated development along
the front Friday afternoon, which will move through Friday evening.
Heaviest rainfall for these periods should again be found in east
central KS, where additional rainfall may cause some flooding
concerns by that time.  Have not issued any headlines for flooding
at this time, but these may be needed for the Friday
afternoon/evening time frame if the front takes its time moving
through.  Have basically disregarded the NAM in making this forecast
as other models are more consistent with each other on the timing of
front and location of heavier amounts of QPF.  Finally, Saturday
should be pleasant with high pressure and associated cooler and much
drier airmass building into the Central Plains.

Saturday Night through Wednesday...

A deep trough across the Great Lakes region will continue pushing
northeast throughout the weekend, leaving behind zonal mid-level
flow. Temperatures will remain in the upper 70s Sunday afternoon. A
brief warmup into the middle 80s is expected on Monday ahead of the
next cold front. Shower and thunderstorm chances will increase
Monday evening as the cold front begins to interact with areas along
the Kansas-Nebraska border. Guidance suggests the front will surge
southward Tuesday afternoon into early Wednesday morning, hence the
highest PoPs for the area. Severe weather appears unlikely as mid-
level flow ahead of the front appears to be too weak for well-
organized convection. Timing of the front is still a bit uncertain,
the GFS is more progressive and has the outlook area completely dry
for the daytime hours on Wednesday, while the EC lingers
showers/thunderstorms through much of the afternoon. Much cooler
temperatures will infiltrate the area Wednesday as daytime highs
only warm into the lower to middle 70s!

&&

.AVIATION...(For the 06Z TAFS through 06Z Thursday Night)
Issued at 1144 PM CDT WED SEP 7 2016

Isolated showers and storms will continue for the next few hours.
Expect that activity to move southward through the morning.
Although possibly staying fairly close to TOP/FOE. A boundary in
the area will lift northward in the afternoon so isolated showers
are possible along that in the afternoon. Only a few models
support this scenario so did not mention in the taf.

&&

.TOP Watches/Warnings/Advisories...
NONE.
&&

SHORT TERM...53
LONG TERM...Baerg/GDP
AVIATION...Sanders

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TOPEKA KS
900 PM CDT WED SEP 7 2016

KSZ008>012-020>024-026-034>040-054>056-058-059-090200-
REPUBLIC-WASHINGTON-MARSHALL-NEMAHA-BROWN-CLOUD-CLAY-RILEY-
POTTAWATOMIE-JACKSON-JEFFERSON-OTTAWA-DICKINSON-GEARY-MORRIS-
WABAUNSEE-SHAWNEE-DOUGLAS-LYON-OSAGE-FRANKLIN-COFFEY-ANDERSON-
900 PM CDT WED SEP 7 2016

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

.DAY ONE...TONIGHT.

A ROUND OF MORE WIDESPREAD THUNDERSTORMS IS EXPECTED OVERNIGHT.
THESE STORMS OVERNIGHT WILL BE CAPABLE OF PRODUCING AREAS OF
HEAVY RAINFALL SOUTH AND EAST OF THE TURNPIKE. THE BEST CHANCE OF
HEAVY RAIN SHOULD BE SOUTH OF INTERSTATE 35.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY.

PERIODS OF THUNDERSTORMS CONTINUE THURSDAY THROUGH FRIDAY
EVENING. A FEW STRONGER STORMS MAY PRODUCE GUSTY WINDS THURSDAY
AFTERNOON...OTHERWISE FOCUS TURNS TO POTENTIAL FOR HEAVY RAINFALL
THURSDAY NIGHT AND AGAIN ON FRIDAY AFTERNOON AND EVENING. AREAS
SOUTH OF INTERSTATE 70 COULD SEE RAINFALL TOTALS OF 1 TO 3 INCHES
AND LOCAL FLASH FLOODING MAY BE POSSIBLE WITH SOME OF THESE
STORMS.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED THROUGH TONIGHT.

&&

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

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE TOPEKA KS
1255 AM CDT THU SEP 8 2016

KSZ038-080630-
WABAUNSEE-
1255 AM CDT THU SEP 8 2016

...SIGNIFICANT WEATHER ADVISORY FOR CENTRAL WABAUNSEE COUNTY UNTIL
130 AM CDT...

AT 1255 AM CDT...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM 5
MILES EAST OF VOLLAND...MOVING NORTHEAST AT 35 MPH.

WIND GUSTS UP TO 50 MPH WILL BE POSSIBLE WITH THIS STORM.

THIS STORM WILL REMAIN OVER MAINLY RURAL AREAS OF CENTRAL WABAUNSEE
COUNTY.

THIS INCLUDES INTERSTATE 70 BETWEEN MILE MARKERS 336 AND 339.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TORRENTIAL RAINFALL IS ALSO OCCURRING WITH THIS STORM...AND MAY LEAD
TO LOCALIZED FLOODING. DO NOT DRIVE YOUR VEHICLE THROUGH FLOODED
ROADWAYS.

&&

LAT...LON 3886 9635 3892 9641 3909 9608 3897 9601
TIME...MOT...LOC 0555Z 244DEG 30KT 3892 9632

BB