Area Forecast Discussion
Issued by NWS St. Louis, MO
FXUS63 KLSX 291745
AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
1245 PM CDT Fri May 29 2015
.SHORT TERM: (This Weekend)
Issued at 248 AM CDT Fri May 29 2015
A few showers dot the radar scope locally, but have my eyes on a
cluster of convection increasing in coverage across eastern KS/OK
early this morning. This activity is moving east at 20KT and is on
schedule to arrive in central MO later this morning between 10 AM
and NOON and eastern MO/western IL between NOON and 3 PM. Additional
storms will likely form this afternoon area wide as the atmosphere
destabilizes. Widespread severe weather is not anticipated, but
just like yesterday a few stronger storms could produce some local
wind gusts and/or small hail. Temperatures will range from the 70s
in central Missouri to the 80s across eastern MO and IL.
Meanwhile, a cold front will begin approaching the area from the
northwest this evening which will shift the focus for convection to
our northern CWA. The front will move southeast across the CWA
tonight and Saturday, reaching St. Louis around 18Z. The best chances
of showers and thunderstorms will accompany the front with a
clearing trend from northwest to southeast Saturday afternoon and
evening. Temperatures on Saturday will depend on convective trends
and frontal position, but generally think upper 60s northwest to 80s
Sunday appears to be dry now as the front pushes south and a ridge
of high pressure builds across the region. It will be a cooler day
with highs struggling to reach 70 degrees.
.LONG TERM: (Monday through Thursday)
Issued at 248 AM CDT Fri May 29 2015
A cutoff low is expected to develop across the lower Mississippi
River Valley underneath a building ridge of high pressure aloft.
Appears the cutoff will stay far enough south that PoPs will be
limited and temperatures should increase through the period back
into the middle 80s. Next trof of low pressure approaches on
Thursday with an increased chance of showers and thunderstorms
across the western CWA.
.AVIATION: (For the 18z TAFs through 18z Saturday Afternoon)
Issued at 1227 PM CDT Fri May 29 2015
There are 2 main areas to watch for precipitation this afternoon.
The first is from central MO into west central IL including KCOU
and KUIN. These terminals will be impacted by a large area of
showers that is lifting northeastward and should consist of
predominatly VFR flight conditions. The other region is from south
central MO through St. Louis and points east where scattered
showers and thunderstorms will prevail. KCPS appears to have the
greatest thunder potential in the short term and thus have a TEMPO
group. There should be a lull of precipitation from the late
afternoon into the very early evening then a large area of showers
and thunderstorms originating in Eastern OK/Southeastern KS/Southwestern
MO should spread across the area and dominate much of the evening
into the overnight hours. Predominately MVFR flight conditions are
expected with this precipitation tonight. A cold front will then
move across the region on Saturday bringing a northwest wind shift
and MVFR cigs.
Specifics for KSTL:
Tough call on direct impacts this afternoon. In the near term it
appears that any thunder threat will be just to the east of KSTL.
However, scattered showers and thunderstorms will dot the area
thru mid afternoon but confidence is not great enough for more
than VCTS at this time. Will monitor closely and AMD if conditions
change. There should be a lull of precipitation from the late
afternoon into mid evening then a large area of showers and
thunderstorms originating in Eastern OK/Southeastern KS/Southwestern
MO should spread across the area and begin impacting the terminal
late this evening and dominate through the overnight hours.
Predominately MVFR flight conditions are expected with this
precipitation tonight. A cold front will then move across the
region on Saturday with FROPA near midday bringing a northwest
wind shift and MVFR cigs.