Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

Area forecast discussion 
National Weather Service Topeka Kansas
352 PM CDT Wed Apr 1 2015

Short term...(this evening through thursday)
issued at 331 PM CDT Wednesday Apr 1 2015

Dew points were slowly increasing across central and eastern Kansas.
Dew points around 50 vary across the County Warning Area with a nose of 55 degree
plus dew points extending north across far eastern Kansas with lwc
now up to 56 degrees at 19z. Latest meso analysis shows an mesoscale convective vortex
moving across southern Missouri with SBCAPE around 1500 j/kg in far
east central and southeast Kansas at 19z. Cap remains in place
across much of the County Warning Area extending into northwest Kansas. Cold front
extended from east central South Dakota into northeast Colorado
while the dryline extended from southwest Nebraska to the east of

Short range high resolution models suggest that convection will
develop in the 23z to 00z time period from northeast Nebraska
southwest to near Phillipsburg and Hays. Storms congeal into a line
and move into north central Kansas after 7 PM and increasing across
the western counties through 10 PM, then becoming widespread across
the County Warning Area as the upper trough and front move through. 850 mb moisture
transport increases along the 850 mb front tonight as it moves
through. Low level jet increasing to 40 to 50 kts from the south
will veer to the southwest gradually through the night focusing
potential for locally heavy rainfall across northeast and east
central Kansas in the 06z-12z time frame. Have increased quantitative precipitation forecast to
around 0.90 inches in east central Kansas. Shear around 35 to 40 kts
and instability around 1200 j/kg along with cooling aloft with the
wave moving through will yield environment for some storms to be
severe this evening across north central and northeast Kansas with
wind and hail the main hazards as the line moves through. Overnight
wave moving through The Rockies will move out into the plains
developing precipitation in the wake of the front and also
increasing ascent across eastern Kansas. The front is expected to
move south of the County Warning Area into southeast Kansas Thursday morning then
stalling out from southern Kansas and southern Missouri atmosphere
across east central and southeast Kansas becomes capped during the
day. 850 mb front will be near the southern County Warning Area and could see some
development in the late afternoon when a weak wave moves through and
cap erodes in the 22z-00z period. Temperatures will be about 15
degrees cooler on Thursday.

Long term...(thursday night through wednesday)
issued at 331 PM CDT Wednesday Apr 1 2015

The surface front should be located somewhere across southeast
Kansas by late Thursday with greatest risk for surface based
convection expected to remain near or just southeast of the County Warning Area
after 00z. However the next upper wave will emerge across the
region Thu night and will act to produce another area of rain
across most of the state. Modest forcing and dry air will act to
limit amounts but most areas should see a least a period of light
rain showers overnight into early Friday before skies clear and
high pressure moves into the area for the weekend.

The weekend looks great with highs in the 60s and 70s and low
humidities. South winds will increase by late day Saturday so
could pose fire weather issues again. The dry weather should
persist through Sunday as Gulf of Mexico moisture will be slow to
return to the area this weekend. The forecast weather pattern by
next Monday and Tuesday will feature a longwave trough across The
Rockies with sfc low pressure somewhere across the plains. Latest
GFS is more progressive with an initial wave Monday which forces a
sfc low into eastern Nebraska and dryline across Kansas while the
European model (ecmwf) is much slower and features a low across eastern Colorado with a
warm front draped across the state. Both show additional energy
moving into the plains which could set the stage for bouts of
thunderstorms into mid week. The details such as timing and
location of features remain uncertain as does the associated
severe weather risk but it would appear that next week could be
active across the region.


Aviation...(for the 18z tafs through 18z Thursday afternoon)
issued at 1232 PM CDT Wednesday Apr 1 2015

Today VFR conditions remain for the afternoon and early evening
with strong southerly winds continuing. All taf sites should get
in on some thunderstorm activity late with some low end MVFR
conditions in association with any storms. The tendency to be later with
the development of thunderstorm activity is consistent with
guidance and actual observations via visible and water vapor
satellite. Confidence in timing right now is medium with the best
chance of a line of activity beginning at kmhk around 8z and
ktop/kmhk around 9z although this may be adjusted further for the
next taf period should the system continue to be slower to
develop. All activity should begin to exit the area after the 12z
time frame as the frontal system pushes to the south and east with
northwest to northerly winds funneling in behind with some Post
frontal stratus.


Top watches/warnings/advisories...


Short term...53
long term...omitt

National Weather Service Glossary of Abbreviations