065 
FXUS63 KLSX 150851
AFDLSX

Area Forecast Discussion
National Weather Service Saint Louis MO
351 AM CDT Wed May 15 2019

.SHORT TERM...  (Through Late Thursday Afternoon)
Issued at 343 AM CDT Wed May 15 2019

Isolated/scattered showers and thunderstorms will continue to track 
to the southeast early this morning, eventually moving out by Noon. 
However, with frontal boundary just south of forecast area, could 
see some redevelopment over the far southern portions of the 
forecast area this afternoon. Otherwise, partly cloudy skies will 
prevail with temperatures warming up into the low 70s to low 80s, 
with the warmest temps over central Missouri.

Mild conditions expected tonight with lows in the upper 50s to low 
60s. In the meantime, another warm front will develop over the area 
and slowly slide to the north as next system approaches on the 
northwest flow aloft. Some weak moisture convergence expected along 
the frontal boundary with weak lift, so have a slight chance of 
showers and a few thunderstorms after 06z Thursday over portions of 
central and northern Missouri, as well as west central Illinois. 

As warm front lifts north of forecast area by Thursday morning, dry 
and much warmer conditions expected with increasing south to 
southwest winds and plenty of sunshine expected. Highs will be in 
the 80s, at least 10 degrees above normal for this time of year.

Byrd

.LONG TERM...  (Thursday Night through Tuesday)
Issued at 343 AM CDT Wed May 15 2019

Upper ridge will remain in place over the region through Friday, 
before beginning to shift off to the east Friday night. Much above 
normal temperatures will persist on Friday with highs in the 80s to 
near 90 degrees, especially in the St. Louis metro area. 

By Saturday, next system will begin to slowly approach the region 
with several rounds of activity firing up ahead of it, so kept 
increasing PoPs with best chances Saturday night through Sunday, 
before tapering off Sunday night. As for severe weather chances on 
Sunday, models have deepening system lifting northward through Iowa 
dragging a pre-frontal trough through region. However, some question 
as to when the trough will slide through. If it holds off until the 
afternoon/evening hours, could see strong to severe storms 
associated with it. The new SPC outlook for Day 5 (Sunday) has
eastern portions of forecast area in a slight risk for severe 
storms. Highs Saturday will be in the upper 70s to upper 80s and 
in the mid 70s to low 80s on Sunday.

Beyond that, extended models have differences on timing and location 
of systems as they slide through region for the beginning of the 
work week. For now will stick with blend of model guidance. 
Temperatures through this period will depend on what model solution 
wins out.

Byrd
&&

.AVIATION...  (For the 06z TAFs through 06z Wednesday Night)
Issued at 1108 PM CDT Tue May 14 2019

An upper level short wave drop SE through the region. Scattered
showers, with a few thunderstorms, continue to move slowly to the
SE. Model guidance continues to suggest these storms will increase
in coverage as they approach KSUS/KCPS. While some uncertainty
remains, believe chances of impacting the terminal are high 
enough that will leave forecast as-is. However, some changes in 
timing may still be needed. Still expect any bkn MVFR cigs to 
remain east of terminals thru Wed. Otherwise, expect CU to develop
on Wed with VFR bases.

SPECIFICS FOR KSTL: SHRA with sct TS continue to move SE 
overnight. Will leave the mention of SHRA as-is for now. Expect 
clouds that develop behind this system to remain VFR. Expect CU to
develop during the day Wed. 

Tilly
&&

.PRELIMINARY POINT TEMPS/POPS...
Saint Louis     78  63  89  67 /  20   5   5   0 
Quincy          76  58  85  65 /   5  20  10  10 
Columbia        80  62  86  64 /  10  10   5   0 
Jefferson City  82  62  87  65 /  10  10   5   0 
Salem           72  57  83  65 /  50   5  10   5 
Farmington      78  61  86  64 /  40   5  10   0 

&&

.LSX WATCHES/WARNINGS/ADVISORIES...
MO...None.
IL...None.
&&

$$
WFO LSX