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AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO
1233 PM CDT Wed May 6 2015

.DISCUSSION...
Issued at 341 AM CDT WED MAY 6 2015

A large area of rain with embedded thunderstorms was slowly tracking 
east across Kansas and Oklahoma. Individual cells within this 
cluster are tracking north, with the mean flow, but as the strong 
upper wave begins to move northeastward early this morning the 
entire area should begin to move into eastern portions of Kansas and 
western Missouri. How well this area stays together with eastward 
propagation is a little uncertain as models show a distinct 
weakening trend before potentially reinvigorating the precipitation 
further east. Overall however, it looks like most folks will see some
precipitation from this rain area as it tracks east. The threat of
severe weather looks low due to limited instability.

The focus then shifts west, into the central Plains, this afternoon, 
for storms that may move into northeastern Kansas and northwestern 
Missouri overnight. Convection looks to fire over central Kansas and 
Oklahoma Wednesday afternoon. This activity may congeal into a 
convective system and track to the east overnight, affecting western 
and northwestern portions of the forecast area. How this possible 
system evolves will have a large role into how convection evolves 
later in the day Thursday. As a result, there is not a lot of 
agreement amongst the models and this reduces confidence in how 
things will unfold. Larger scale models show the area becoming 
moderately unstable Thursday afternoon with shear increasing during 
the day. These models develop convection over eastern Kansas and 
then track it to the east during the evening/overnight hours. Even 
with increasing shear later in the day, we may still only see 25 to 
30kts 0-6 km shear and as a result the threat of severe storms looks 
low. But there may be some strong storms and a random severe storm 
given the instability.

A cold front should move into the area Friday and stall right 
through the middle of the forecast area. Moderately unstable 
conditions are expected to develop south of the front and with 
increasing flow aloft leading to greater shear, a few severe storms 
look possible on Friday afternoon and evening. The most likely areas 
look to be south of the Missouri River, with the greatest risk of 
severe storms over southern and southeastern Kansas. 

More thunderstorms are possible Saturday, mainly over the southern 
half of the forecast area, south of the stalled frontal boundary. 
Once again, moderately strong instability is expected to develop 
south of the front. Wind shear again looks to be marginal throughout 
the day and may actually decrease during the afternoon and evening 
hours. So while the threat of severe weather looks low, a few strong 
to severe storms look possible given the amount of instability. 

Sunday continues to look like the best potential for severe weather 
for the central to eastern Plains. A potent upper level shortwave 
trough is expected to move into the Plains during the day leading to 
the development of a strong area of low pressure. Again, moderately 
strong instability will develop during the afternoon. However, much 
stronger shear is expected as a strong jet streak rotates around the 
base of the trough. Forecast soundings show a cap in place that 
eventually erodes. Forecast hodographs relatively linear which 
suggest a good potential for splitting supercells eventually 
evolving into a line of storms. Still plenty of time to assess the 
potential for severe but models have remained consistent over the 
last few runs leading to increased confidence that Sunday has a good 
potential for severe storms through the central to eastern Plains.

With all the rounds of possible convection over the next week, there
may be widespread heavy rainfall. But all of this is conditional on
where each round of storms develops and tracks through. So there is
quite a bit of uncertainty with just how much rainfall any specific
area may see. Overall, it's possible much of the forecast area sees
several inches of rain through late this week and into early next week.

&&

.AVIATION...(For the 18Z TAFS through 18Z Thursday Afternoon)
Issued at 1229 PM CDT WED MAY 6 2015

Afternoon light rain showers are moving out of the area, and should
only pose a hazard to the terminals for a couple more hours. After
that there will be a prolonged lull in the action before showers and
thunderstorms that form out across Central Kansas move east and into
the terminals early Thursday morning. At this point the exact timing
of the rain is uncertain, as is whether the convection will even
reach the terminals in the first place. Otherwise, only anticipating
VFR conditions with persistent gusty south winds. 

&&

.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&

$$

DISCUSSION...CDB
AVIATION...Leighton

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