Area forecast discussion
National Weather Service St Louis MO
341 PM CDT Wednesday Jun 19 2013
Short term...(through late tonight)
issued at 340 PM CDT Wednesday Jun 19 2013
Isolated thunderstorms are possible late this afternoon and early this
evening...especially in vicinity of a weak frontal boundary which is draped across
the region. Models depict an environment with up to 1000 j/kg of
cape...very little cinh...less than 15 kts of 0-6 km bulk
shear...and skinny cape profiles on BUFKIT soundings...therefore the
expectation is that any isolated convection which develops this afternoon
should remain fairly weak and dissipate with the loss of daytime
heating. A few stray rain showers/thunderstorms and rain may work into the far western County Warning Area
very early tomorrow morning ahead of a shortwave which is moving
through the plains. Winds will gradually become southeasterly tonight as a
surface high over the Great Lakes shifts eastward.
Kanofsky
Long term...(thursday through next wednesday)
issued at 340 PM CDT Wednesday Jun 19 2013
(thursday through saturday)
Forecast area to remain in warm sector on Thursday. As for precipitation
chances will depend on how far east the remnants of an mesoscale convective system over Kansas
makes it as it drifts east towards central MO by midday Thursday.
For now have chance probability of precipitation over Central/Northeast MO...with slight
chances further east. Otherwise...warming trend to continue with
highs in the middle 80s to around 90.
Thursday night...low level jet and frontal boundary focus activity
just to our north over Iowa...not sure how far south southern edge
may be...so kept slight chance/chance probability of precipitation in our far northern
counties after 06z Friday. Mild conditions to persist with lows only
dipping into the upper 60s.
Models continue to show corfidi vectors pointing to a
southeasterly/southerly trajectory for any complex that develops to
our north...so could see dying mesoscale convective system move into forecast area on
Friday. For now have best chances over far northern portions of
County Warning Area...with silent slight chance probability of precipitation further south. Highs will be in
the upper 80s to low 90s.
Could see a repeat of this Friday night and Saturday...but with
remnants a bit further east on Saturday...so have silent slight
chance probability of precipitation during the day on Saturday. Lows Friday night will be in
the low 70s and highs on Saturday in the low 90s.
(Saturday night through wednesday)
Upper level ridge builds in a bit more for the last half of the
weekend with activity shifting a bit further north. But hot and
humid conditions to persist with highs on Sunday in the low 90s.
Then upper level ridge to flatten a bit for the beginning of the
work week...then next weather system approaches area by Wednesday.
But confidence is low on how far south and east activity will make
it so kept silent slight chance probability of precipitation for rest of forecast period for
portions of the forecast period. Otherwise...highs will remain in
the upper 80s to low 90s and lows in the low 70s.
Byrd
&&
Aviation...(for the 18z tafs through 18z Thursday afternoon)
issued at 1118 am CDT Wednesday Jun 19 2013
Isolated thunderstorms are possible this afternoon near a weak frontal
boundary however sparse coverage precludes a mention in the tafs
at this time. VFR conditions are expected to prevail outside of any
thunderstorms which develop. Light Ely winds will gradually turn southeasterly
then southerly late in the taf period.
Specifics for kstl...isolated thunderstorms are possible this afternoon
near a weak frontal boundary however coverage will be sparse. Light
winds will gradually turn southeasterly then become southerly late in the taf period.
Kanofsky
&&
Lsx watches/warnings/advisories...
MO...none.
Illinois...none.
&&
$$
Weather forecast office lsx
