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Office: LSX

FXUS63 KLSX 172329
AFDLSX

Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
629 PM CDT Tue Jul 17 2018

.SHORT TERM...  (Through Late Wednesday Afternoon)
Issued at 327 PM CDT Tue Jul 17 2018

High pressure currently across the Upper Midwest will slowly move
southeastward into lower Michigan on Wednesday afternoon. This
will keep a dry easterly component to the low-level flow and by
and large keep the bi-state area slightly below normal for
temperatures and dry. Exception could be far southern and western
sections of the forecast area where weak moisture convergence and
better instability will reside late tonight into the day on
Wednesday.

Gosselin

.LONG TERM...  (Wednesday Night through Next Tuesday)
Issued at 327 PM CDT Tue Jul 17 2018

(Wednesday Night - Friday)

A potentially active period of weather is in line for Thursday and
Friday across the mid-Mississippi Valley. Lots of uncertainty
however also in this period as to how the closed low in the Upper
Midwest evolves through late week, in addition to its associated
frontal boundaries. General consensus is for a weak warm front to
move through the CWA sometime on Thursday. Guidance suggests some
thunderstorm activity along this convergence zone, which will
shift east/northeast with time.

Atmosphere will be plenty unstable with the passage of this warm
front late Thursday afternoon and overnight. There certainly is
the potential for rigorous thunderstorm development upstream of
the area somewhere over the mid-Missouri Valley along/ahead of
approaching cold front as midlevel temperatures cool ahead of
closed low. With impressive deep-layer shear (especially for July)
in conjunction with a very unstable atmosphere, any storms that
do develop would likely maintain organization and severity through
the night. Large hail and damaging winds look to be the main
threats. However, as alluded to above, there is a lot of
uncertainty with this particular storm system. More specifically,
NWP guidance is highly uncertain as to location and speed of cold
front in the Thursday afternoon through Friday timeframe.

Thunderstorms, some possibly strong to severe, will remain possible
on Friday, but of course any activity on Friday will be heavily
dependent on antecedent convection.

Temperatures for most of the period will remain mostly near normal.
Exception probably will be on Friday afternoon as high temperatures
ahead of the cold front likely reach into at least the lower 90s.

(Friday Night - Next Tuesday)

Closed low is expected to dive southeastward into the Ohio Valley by
this weekend as it gets cutoff from the mean flow across southern
Canada. This low should finally open up as it gets kicked out
northeastward by the next approaching system into south-central
Canada by Monday. Synoptic upper-level flow across the area however
will remain mostly northwesterly, and with the surface front well to
the south of the area, a cool and dry weather pattern should be in
store.

Gosselin
&&

.AVIATION...  (For the 00z TAFs through 00z Wednesday Evening)
Issued at 626 PM CDT Tue Jul 17 2018

VFR conditions through forecast period. Otherwise, light east to
southeast winds. Could see some isolated storms over KCOU by 18z
Wednesday, so added vicinity ts mention after 18z.

SPECIFICS FOR KSTL:
VFR conditions through forecast period. Otherwise, light east to
southeast winds.

Byrd
&&

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

$$

WFO LSX



Office: SGF FXUS63 KSGF 172251 AFDSGF Area Forecast Discussion National Weather Service Springfield MO 551 PM CDT Tue Jul 17 2018 .SHORT TERM...(This evening through Wednesday) Issued at 241 PM CDT Tue Jul 17 2018 The line of storms that pushed across extreme southeastern Kansas and far southwestern Missouri earlier this afternoon, has now pushed south of the area. The outflow has well out ran the storms farther north, which lead to the line falling apart across the area. Additional scattered storms are developing on the outflow. A few isolated storms will be possible else where across the area this afternoon into this evening. All in all the severe risk will be low but a few strong storms will be possible. The best potential for strong storms will be on the outflow across far southern Missouri this afternoon. Isolated storms will likely occur at times into the overnight hours. Late tonight into Wednesday morning another complex of storms may develop across Kansas and spread east/southeast across the area. A few strong to severe storms will be possible. Just like today scattered storms will be possible Wednesday afternoon and evening. If enough instability can develop after any morning storms, a strong to severe risk will occur into the evening hours Wednesday, with damaging straight line winds the main risk. Highs on Wednesday will generally warm into the middle 80s to around the 90 degree mark. .LONG TERM...(Wednesday Night through Tuesday) Issued at 241 PM CDT Tue Jul 17 2018 The upper level ridge will remain west of the area through the rest of this week, leaving the region in an upper level northwest flow pattern. This will allow a few disturbances to track southeast through the northwest flow and will have to watch for late night/morning complex of storms moving across the region through Friday. Redevelop of isolated storms will be possible in the afternoon/evening hours each day through Friday. Highs on Thursday and Friday will generally warm into the lower to middle 90s, though portions of southeastern Kansas and western Missouri may be able to warm into the upper 90s in spots if any morning clouds clear before peak heating. An upper level trough and weak front will push southeast through the region Friday night into Saturday. This will push a drier air mass into the area with no rain expected this weekend into early next week. Highs this weekend into early next week will warm into the upper 80s to the lower 90s. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 548 PM CDT Tue Jul 17 2018 Scattered convection occurring across the CWA, affecting JLN/BBG terminals with light shower activity as of 2230z. Will go with some light showers for the onset of the 00z TAFS there, but will keep in VFR conditions. May have additional convection moving in late tonight and into Wednesday and will handle with some prob30 groups for now. Outside of convection, will continue with VFR, but convection may allow for some brief MVFR/IFR conditions to develop. && .SGF WATCHES/WARNINGS/ADVISORIES... MO...NONE. KS...NONE. && $$ SHORT TERM...Wise LONG TERM...Wise AVIATION...Lindenberg
Office: EAX FXUS63 KEAX 172336 AFDEAX AREA FORECAST DISCUSSION National Weather Service Kansas City/Pleasant Hill MO 636 PM CDT Tue Jul 17 2018 .Discussion... Issued at 312 PM CDT TUE JUL 17 2018 Message of the day: A couple of rounds of storms possible this week which could bring some much needed rain (0.5 inch to 1.25 inch) with heavier amounts across northern MO. A MCV is still making its way across the area, unfortunately though, most of the precipitation associated with it evaporated as it moved into our area thanks to dry air advecting in from the east. Some have been lucky though with the precipitation keeping it together in our northwest and to our southwest. PWAT values are near 2.00 inches, which is above normal for this time of year, so those areas should be seeing decent rain makers. The system should continue to weaken as the day progresses, eventually fizzling out this evening as the upper-level shortwave trough fades away into the upper-level pattern. Before this happens though, the storm cluster should continue moving southeast providing some rain chances for those along the MO/KS border. No severe weather is expected with this system, but isolated flooding should be kept in mind as a possible concern. Given the drought conditions though, especially in northern MO and KS, this rain should be more beneficial than harmful. Another round of storms is possible tomorrow across much of the forecast area, with a surface boundary setting up with a subtle shortwave trough. Locally heavy rainfall is possible, but severe weather is not anticipated with this activity right now. Overnight, Wednesday into Thursday, a more robust shortwave trough will take shape and move across the Northern Plains. This will generate a MCS over the SD region, which will eventually head toward MO and KS. This will be the best chance for rain this week for everyone, though northern MO is in the best position to see this precipitation right now. Gusty winds may be possible with this round, but localized flooding will again be the main concern with moderate to heavy rainfall expected and PWATs near 2 inches. We will need to keep tabs on soil conditions to see how earlier rains may change things, but again, given the current drought situation, these rains should be more beneficial. There is another chance for nocturnal convection to move into our area Friday morning, though, there isn't great consensus among the NAM, ECMWF, and GFS. The NAM keeps us dry, with the ECMWF getting part of the forecast area wet, and GFS getting the entire area very wet. All three suggest a shortwave trough will round the larger upper-level system, it is more of a matter of where it will set up. Wherever it does, locally heavy rainfall will again be possible. Temperature-wise, Wednesday looks to be our coolest day, with highs in the upper 80s and Thursday being the warmest day as we enter the warm sector of the surface low. A 'cold front' is schedule to move through the area Thursday, but unfortunately it won't do much to the temperatures. This weekend, high pressure will move into the area, keeping things dry, and temperatures near normal. && .Aviation...(For the 00Z TAFS through 00Z Wednesday Evening) Issued at 636 PM CDT TUE JUL 17 2018 Showers and thunderstorms are prevailing across some of the state line terminals this evening. However, the activity is rather progressive, and should not linger at the terminals this evening. More showers are possible Wednesday, but confidence on when and where they will bubble up is too low to warrant including in TAF at this time. && .EAX WATCHES/WARNINGS/ADVISORIES... KS...NONE. MO...NONE. && $$ Discussion...Grana Aviation...Cutter