Scientific Forecaster Discussion
Area forecast discussion...updated aviation
National Weather Service St Louis MO
628 am CDT Tuesday Jul 7 2015
Short term: (through late this afternoon)
issued at 315 am CDT Tuesday Jul 7 2015
Mesoscale convective vortex currently moving across Columbia Missouri with band of light to
moderate rain stretching from central Illinois through southwest
Missouri. As expected cold front is slowling its progress southeast
with it now located from just south of Kansas City Missouri to
Quincy Illinois. Rainfall amounts up to this point have generally
been 1 to 2 inches across central and northeast Missouri with lesser
amounts to the southeast. The near term radar trends suggest that
the band of rain will continue to push east through the St. Louis
metropolitan through sunrise with additional showers and thunderstorms
developing along the front this afternoon as it slowly sinks south
into southern Missouri and southwest Illinois. Temperatures are
tricky with the front...clouds and rain. St. Louis is still 80
degrees at 3 am in the morning. Kept the forecast nearly unchanged
with highs in the middle 70s except the far southeast zones where
lower 80s will be possible.
Long term: (tonight through monday)
issued at 315 am CDT Tuesday Jul 7 2015
Focus continues to be precipitation chances.
Cold front will continue to push southward today and push bulk of precipitation S of
the County Warning Area by this eve, or at least across the southern portions of the County Warning Area.
Have delayed timing of precipitation lifting northward back into the area until
after midnight. Some question remains how quickly the next round of
precipitation will move northward as the surface low and associated cold front lifts northward
back into the area. This system will be responsible another round of
heavy rain on Wednesday as the surface low passes through the region.
Will keep the Flash Flood Watch as-is for now, but may need to be
expanded in area as well as into Wednesday night.
As for temps, have continued a cool trend for Wednesday due to rain expected
through much of the day. Have lowered temperatures from previous forecast and
future updates may need to lower these temperatures more.
For Friday and beyond, models forecast height rises through next weekend and
have raised temperatures accordingly. Temperatures may need to be raised more from
going forecast, but some questions remain regarding placement of the
surface fnt. Models forecast the fnt remaining just north of the County Warning Area this weekend
and into next week. However, as the upper ridge builds to the W,
area comes under northwest flow and should allow the fnt, as well as storms,
to drop southward into the area.
Aviation: (for the 12z tafs through 12z Wednesday morning)
issued at 623 am CDT Tuesday Jul 7 2015
A cold front extending from near kcou to kppq will steadily March
south across the remainder of the County Warning Area today with a north wind in
its wake. Rain will gradually diminish from north to south this
morning and be confined to the far southern sections of the County Warning Area by
this evening. Next round of showers and thunderstorms with
potential of heavy rainfall will take shape tonight and build
north into the County Warning Area by daybreak tomorrow. Winds will gradually veer
to the east. Believe initial IFR/MVFR ceiling will improve with
time today...especially at KUIN and kcou.
Specifics for kstl:
Light rain showers will continue for much of the morning as cold
front pushes through the terminal complex. North wind to take over
with MVFR ceiling gradually lifting. Next round of
rain...potentially heavy...will arrive around daybreak tomorrow
and continue much of the day on Wednesday. Conditions will likely
drop back to MVFR or IFR conditions tomorrow morning.
MO...Flash Flood Watch through Wednesday evening for Audrain MO-Boone
MO-Callaway MO-Cole MO-Crawford MO-Franklin MO-Gasconade MO-
Jefferson MO-Knox MO-Lewis MO-Lincoln MO-Marion MO-Moniteau
MO-Monroe MO-Montgomery MO-Osage MO-Pike MO-Ralls MO-Shelby
MO-St. Charles MO-St. Louis city MO-St. Louis MO-Warren MO-
Illinois...Flash Flood Watch through Wednesday evening for Adams Illinois-Brown
Illinois-Calhoun Illinois-Greene Illinois-Jersey Illinois-Macoupin Illinois-Madison Illinois-
Monroe Illinois-Pike IL-St. Clair Illinois.
Weather forecast office lsx