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Area Forecast Discussion (AFD)

Issued by Springfield, MO (SGF)

                            
000
FXUS63 KSGF 210901
AFDSGF

Area Forecast Discussion
National Weather Service Springfield MO
401 AM CDT Sun Jul 21 2019

.SYNOPSIS...
Issued at 222 AM CDT Sun Jul 21 2019

As of 08z, GOES infrared satellite imagery shows a large 
Mesoscale Convective System (MCS) over southern Iowa and northern 
Missouri. This MCS will gradually drift south and decay through 
the early morning hours as it moves into an area of lower buoyancy
and shear. It will also be fighting mid-level dry air, as seen in
the 00z SGF sounding. Nevertheless, some convective activity may 
linger in areas north of Highway 54 through sunrise.

The main thing to note with this decaying MCS is the outflow
boundary(s) that have surged out ahead of it. Seen clearly on both
radar and infrared satellite imagery and radar, a well defined
outflow boundary currently arcs from Nevada to Bolivar to Salem.
This outflow will continue drifting south but will slow down,
weaken, and eventually stall somewhere in between Interstate 44 
and the Missouri/Arkansas state line by mid morning. This feature
could become important later today.  More on that below.

Another thing to note with the decaying MCS is the associated
cloud shield that will be prevalent this morning across the
northern half of our CWA. This cloud shield will be co-located
with many of the counties in the Excessive Heat Warning. Solar
insulation will not be particularly strong in those areas with 
the cloud shield expected to mix away by late morning, but it 
could have enough of an effect to threaten meeting our current 
heat headlines. No changes have been made overnight regarding the 
Excessive Heat Warning and Heat Advisory. These products will 
continue until 7pm.

&&

.SHORT TERM...(Today through Monday) 
Issued at 222 AM CDT Sun Jul 21 2019

The main forecasting concern today will be timing convection, as
there is more than one opportunity. There is also severe
potential.

This afternoon: With at least one outflow boundary lurking across
our southern CWA, storms could initiate along the boundary beyond
18z. RAP analysis indicates a very moist and sufficiently unstable
air mass beyond 18z with dewpoints in the lower 70s and MLCAPE 
values >1500 J/kg, respectively. With low-level moisture, adequate
instability, and a source of lift along the residual outflow 
boundary thunderstorms are at least a possibility. The limiting 
factor, however, is a moderate layer of dry air in the mid- and 
upper-levels. If we can generate enough instability to overcome 
the dry mid-level air, then storm changes greatly increase. RAP 
analysis shows the best chance for afternoon convection south of 
Interstate 44 and, perhaps, east of Highway 65. This will be the 
area with the lowest CIN and the highest moisture/instability. 
With PWAT values nearing 2.0 inches and a theta-E differential > 
35 K, any scattered convection this afternoon could contain strong
precip loading/downburst winds that would produce severe level 
wind gusts.

Late tonight: The better chance for convection comes late tonight
into Monday as a cold front drops into our area from the north.
Accompanying this front will be a robust shortwave trough coming
in from eastern NE/KS. The deterministic model solutions are now
in good agreement of this shortwave trough accelerating out ahead
of the surface front with a forward propagating MCS moving into
central Missouri and the eastern Ozarks late tonight. This MCS
will likely pack a punch wherever it tracks. Again, with theta-E
differences greater than 35 K, strong cold pooling could produce
outflow winds greater than 58 MPH.

Temperatures Sunday will be in the lower to mid 90s, while
temperatures on Monday only reach the low 80s in wake of the
decaying MCS and passing cold front.

.LONG TERM...(Tuesday through Saturday) 
Issued at 222 AM CDT Sun Jul 21 2019

A strong surface anticyclone settles into the Central Plains
Tuesday through Thursday. Dry conditions can be expected along
with daily temperatures in the low 80s and overnight lows in the
upper 50s to low 60s.

Temperatures will moderate Friday and Saturday into the mid 80s as
an upper-level ridge begins to set up once again.

&&

.AVIATION...(For the 06Z TAFS through 06Z Sunday night)
Issued at 1231 AM CDT Sun Jul 21 2019

No forecasting concerns are expected overnight across the regional
terminals. VFR conditions will persist. Some high-level clouds 
will gradually stream in from the north, where a decaying complex 
of storms is slowly moving southward. Surface winds overnight 
will generally be southerly at around 10 knots.

Beyond 12z, there is a chance for scattered afternoon showers and
storms. Confidence is currently low in what the areal coverage
will be, therefore no mention has been made with this issuance of
TAFs.


&&

.SGF WATCHES/WARNINGS/ADVISORIES...
MO...Heat Advisory until 8 PM CDT this evening for MOZ082-083-090>092-
     094>098-101>106.

     Excessive Heat Warning until 8 PM CDT this evening for 
     MOZ055>058-066>071-077>081-088-089-093.

KS...Excessive Heat Warning until 8 PM CDT this evening for KSZ073-
     097-101.

&&

$$

SYNOPSIS...Albano
SHORT TERM...Albano
LONG TERM...Albano
AVIATION...Albano