Area Forecast Discussion
Issued by NWS Kansas City/Pleasant Hill, MO

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44
FXUS63 KEAX 231724

Area Forecast Discussion
National Weather Service Kansas City/Pleasant Hill MO
1224 PM CDT MON MAY 23 2016

Issued at 350 AM CDT MON MAY 23 2016

Messy, convoluted forecast this week with thunderstorm chances in
nearly every period, but no clean genesis for these storms with main
forcing mechanisms remaining out west.

For this morning, the remnants of afternoon convection along the
High Plains has morphed into two regions of thunderstorms across
central Nebraska and central through southern Oklahoma. The southern
of the two complexes has developed into a southward-diving MCS and
will not impact the forecast area, while the northern segment is on
a slightly more favorable trek toward the far northwest corner of
the CWA; however, its outflow boundary has separated well ahead of
the convection, and does not bode well for its longevity. High-res
models will not let go of the idea that the southern complex will
eventually expand northward and connect the two regions of lingering
convection, but am a bit concerned about the realism of this north-
ward expansion given warming cloud tops across KS and weakening
trends of any convection north of the primary MCS, save a few very
isolated storms struggling to develop in southeast KS. Isentropic
lift does increase over central and eventually eastern KS over the
next 3-6 hours and thus will need to monitor this area for any
developing accas as an indicator that CI is still possible, but if
not, PoPs will need to be significantly reduced today. An ill-timed,
compact shortwave trough may slide across the region early this
afternoon and allow for some reinvigoration of any weak convection
that does make it into the CWA this morning, but if not much is
going on at the time it passes over, doesn`t seem likely that what
little forcing can be derived from this wave will be enough to kick
off new convection.

The outflow boundary from ongoing storms across Nebraska may park
from northern through central KS and serve as a focus for convective
initiation this afternoon, which could translate east with time and
impact the region late this evening, but could also be hampered by
subsidence in the wake of the early-afternoon shortwave trough and a
diurnal decrease in surface-based instability as it nears our CWA.
After that, it will be another waiting game to see if nocturnal
convection can develop and move into our area late tonight into
Tuesday morning as another round of isentropic lift develops and
slides east.

Increasing surface moisture and warm low-level temperatures will
create a breeding ground for instability Tuesday through at least
Thursday, keeping thunderstorm chances alive through the rest of
the work week. The only day that random airmass thunderstorms look
possible is Tuesday due to supportive lapse rates aloft and very
little, if any, capping. Shear will be weak on Tuesday and should
keep wide-spread, organized severe weather chances low despite very
high CAPE bordering on the 4000-5000 J/kg range in model-land, but
downburst winds or hail from a particularly tall core keeps the
severe chances non-zero, especially if storms can initiate in or near
the CWA before storms conglomerate. Capping will become an increasing
complication Wednesday and Thursday as a surface low finally ejects
out of the High Plains and forces the building thermal ridge
eastward, but will also push the dryline and potential convective
initiation eastward, so the end result will be a toss up -- storms
will be altogether less likely, but any storms that do develop have a
better potential to become severe due to better shear and a shorter
residence time between initiation and the western edge of the CWA.

The surface low is then kicked northward by a substantial ejection
of shortwave energy out of the upper trough to over the desert
Southwest, and separates from the feed of moisture, allowing the
dryline to retreat back to the west on Friday. The western longwave
trough will also be in transition as this wave departs and the next
reinforcing low slides down from the Pacific NW, probably resulting
in a bit of a down day for storms and especially severe potential
either Friday or Saturday, depending on the timing of all these
features. This forecast may repeat in 7ish days when the next trough
settles into the southwestern U.S., but for now suffice to say that
any decrease in precipitation chances this weekend will be temporary
and the pattern will remain active through the foreseeable future.

Temperatures throughout the forecast period will depend greatly on
the coverage and longevity of nocturnal/morning convection, but have
the potential to reach the mid to even upper 80s, especially by
Thursday or Friday. Dewpoints will climb into the upper 60s to near
70 by Tuesday and linger there through the end of the work week, and
lows will also linger in or slightly above this range.


.Aviation...(For the 18Z TAFS through 18Z Tuesday Afternoon)
Issued at 1219 PM CDT MON MAY 23 2016

Thunderstorm activity will build into the region through much of the
afternoon hours today. An outflow boundary to the NW of the terminals
will reduce visibilities during the early afternoon, though ceilings
should remain VFR during this time and beyond. More stratiform
precipitation will then impact the late afternoon. Whether or not
this lingers into the evening hours is uncertain, though thinking as
of now that we should see a break in the activity beginning this
evening and into most of the overnight. By tomorrow morning,
thunderstorms look to redevelop. During this time, ceilings could
become MVFR or even IFR. This will all depend on how activity trends
tonight. Will revisit this scenario for the 00Z forecast.


.EAX Watches/Warnings/Advisories...


Aviation...Welsh is the U.S. government's official web portal to all federal, state and local government web resources and services.