Scientific Forecaster Discussion
Area forecast discussion...updated aviation
National Weather Service St Louis MO
630 PM CDT Sat Aug 1 2015
Short term: (through late tonight)
issued at 217 PM CDT Sat Aug 1 2015
Scattered thunderstorms have developed this afternoon in vicinity of a boundary
located across central MO. Since the environment is weakly capped,
these storms should continue percolating at least until the loss of
850 mb low level jet associated with a shortwave moving through Iowa is expected to
support a nocturnal mesoscale convective system which may affect parts of northeastern MO
and west central IL, especially after midnight. Sh/ts remnants could
drop farther southeast than currently forecast however confidence is
too low to extend probability of precipitation at this time.
Long term: (sunday through next saturday)
issued at 217 PM CDT Sat Aug 1 2015
Hot and humid conditions expected Sunday with high temperature in
the lower to middle 90s and dewpoints near 70 degrees. I can't
completely rule out a shower or storm first thing in the morning
across far northeast Missouri and west central Illinois...but better
chances of measurable rain should reside further north across the
upper Mississippi River valley.
The next cold front and chance of thundertorms will move south into
Missouri and central Illinois Sunday night...reaching Interstate 70
by 12z Monday morning. Front will slow and eventually become
orientated from northwest Missouri to the bootheel by the evening.
Several shortwaves will interact with the nocturnal low level jet to
provide chances of thunderstorms across the area Monday night
through at least Wednesday morning. GFS is certainly more robust
with quantitative precipitation forecast than other models at this time...but can't discount its
solution given pattern and available moisture. Temperatures will be
slightly cooler on the east side of the front with highs in the
middle to upper 80s.
Active weather pattern stays in place through the end of the work
week as a front wavers across the area under northwest flow aloft.
Daily high temperatures will continue to fall through the period
with highs forecast in the lower 80s next Saturday.
Aviation: (for the 00z tafs through 00z Sunday evening)
issued at 625 PM CDT Sat Aug 1 2015
Primary focus over the next 24-30 hours will be on chances of
convection affecting terminals. Predominantly dry weather is still
anticipated...but will have to watch storms just west of kcou
through early this evening. In addition...a complex of storms
should develop across the middle-Missouri Valley tonight and may
affect KUIN toward daybreak. Outside of any thunderstorms...VFR
conditions with light mainly westerly winds will continue.
Specifics for kstl:
Primary focus over the next 30 hours will be on chances of
convection affecting the terminal. Predominantly dry weather is
still anticipated...but will have to watch a complex of storms
should develop across the middle-Missouri Valley tonight. Those
storms may put down an outflow boundary which could try and fire
up a few isolated storms near kstl late Sunday morning or ealy
Sunday afternoon. However...chances are too low at this time to include in
the taf. Outside of any thunderstorms...VFR conditions with light
mainly westerly winds will continue through Sunday night.
Preliminary point temperatures/pops:
Saint Louis 77 95 79 89 / 10 10 20 10
Quincy 70 90 69 86 / 50 20 30 10
Columbia 70 93 71 91 / 20 10 20 10
Jefferson City 69 94 72 93 / 20 5 20 10
Salem 68 91 72 88 / 10 10 20 10
Farmington 67 91 72 90 / 20 5 10 10
Weather forecast office lsx