Area Forecast Discussion
Issued by NWS Kansas City/Pleasant Hill, MO
FXUS63 KEAX 231057
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO
557 AM CDT Thu May 23 2013
.SHORT TERM...(Today through Saturday)
Issued at 325 AM CDT THU MAY 23 2013
Light rain showers/sprinkles have been moving south through Iowa
early this morning around the upper-low moving across the Upper
Mississippi valley. There is a chance that these could last into
northern and northeastern Missouri this morning, so have added a
mention of sprinkles. Otherwise, quiet conditions are expected with
thicker stratocu persisting through much of the day across northern
and northeastern Missouri. This area will see highs in the mid 60s as
cloud cover and continued cool northerly/northeasterly winds keep
temperatures seasonally cool. Southern and western portions of the
forecast area will see temperatures in the lower 70s as cloud cover
will be less persistent there.
Friday should be a bit warmer across the area but temperatures are
still expected to be in the lower 70s. The next decent chance for
rain will come late Friday night and into Saturday. A strong
low-level jet is expected to develop over the Plains, focusing on
western to central Nebraska and Kansas. This will likely trigger
storms across the region and as the low-level jet veers and shifts
east, the focus and stronger, moist isentropic ascent will as well.
This may bring whatever forms in the Plains into mainly northern
Missouri late in the night. We will also be seeing more broad
isentropic lift through the area earlier in the night, so cannot
rule some isolated showers or storms out earlier. But the best
chances will be later when better moisture and ascent arrive.
Mid-level flow will become more persistently from the south to
southwest allowing continued moisture advection into the region.
This will result in at least a chance for thunderstorms through the
day and into the overnight. While it doesn`t look like the start of
the Memorial Day weekend will be a washout with thunderstorms
everywhere, the chances will be there throughout the day for
scattered showers and storms unfortunately. The threat for severe
weather looks low at this through Saturday night as shear and
instability will be rather limited.
.LONG TERM...(Sunday through Wednesday)
Issued at 325 AM CDT THU MAY 23 2013
Upper-level ridging will remain in place across the central U.S. for
much of next week. Despite this ridge, all medium range guidance
continues to produce multiple rounds of convection across the Plains
into the Upper Midwest through most of the extended period as the
upper trough to the west sends continuous weak impulses into the
region. Airmass in place will be somewhat unstable, so several
rounds of thunderstorms are certainly a possibility, but the
presence of weak capping aloft and the lack of any well-defined
forcing mechanism suggest these model PoPs are probably overdone.
While it is unlikely we will see thunderstorms every day next week
like the models suggest, its not yet possible to pinpoint when/where
the highest chances will be. Therefore kept low-end chance PoPs for
much of the extended period but tried to trend drier by Wednesday as
upper level heights begin to rise overhead. Wind fields will be weak
so significant severe weather seems unlikely at this point.
.AVIATION...(For the 12Z TAFS through 12Z Friday Morning)
Issued at 545 AM CDT THU MAY 23 2013
MVFR ceilings are expected through early this afternoon. And based on
upstream observations and model guidance, there will likely be
several hours of fuel-alternate MVFR cigs from late this morning
through early afternoon. Winds will shift from the northwest to the
northeast through the day but should generally be light. Ceilings are
expected to break up and scatter out by late this afternoon. Once
this occurs skies should remain clear to mostly clear through the night.