Severe Thunderstorm Warning 19, NWS St. Louis, MO

087 
WWUS53 KLSX 062142
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
442 PM CDT SUN MAY 6 2018

MOC137-062151-
/O.CAN.KLSX.SV.W.0019.000000T0000Z-180506T2215Z/
Monroe MO-
442 PM CDT SUN MAY 6 2018

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN MONROE COUNTY IS
CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

LAT...LON 3933 9227 3931 9215 3901 9192 3897 9232
      3924 9234 3925 9233 3925 9231 3928 9231
TIME...MOT...LOC 2141Z 334DEG 16KT 3923 9222 

$$

MOC007-019-027-062215-
/O.CON.KLSX.SV.W.0019.000000T0000Z-180506T2215Z/
Boone MO-Audrain MO-Callaway MO-
442 PM CDT SUN MAY 6 2018

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 515 PM CDT
FOR NORTHEASTERN BOONE...WESTERN AUDRAIN AND NORTH CENTRAL CALLAWAY
COUNTIES...

At 441 PM CDT, a severe thunderstorm was located near Sturgeon,
moving southeast at 20 mph.

HAZARD...60 mph wind gusts and quarter size hail.

SOURCE...Radar indicated.

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs, siding, and trees.

Locations impacted include...
Columbia, Centralia, Hallsville, Sturgeon, Murry and Hatton. 

This also includes  Finger Lakes State Park.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

To report severe weather contact your nearest law enforcement agency.
They will send your report to the National Weather Service office in
St Louis.

&&

LAT...LON 3933 9227 3931 9215 3901 9192 3897 9232
      3924 9234 3925 9233 3925 9231 3928 9231
TIME...MOT...LOC 2141Z 334DEG 16KT 3923 9222 

HAIL...1.00IN
WIND...60MPH
 
$$

Gosselin

241 
WWUS53 KLSX 062214
SVSLSX

Severe Weather Statement
National Weather Service St Louis MO
514 PM CDT SUN MAY 6 2018

MOC007-019-027-062224-
/O.EXP.KLSX.SV.W.0019.000000T0000Z-180506T2215Z/
Boone MO-Audrain MO-Callaway MO-
514 PM CDT SUN MAY 6 2018

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN BOONE...WESTERN
AUDRAIN AND NORTH CENTRAL CALLAWAY COUNTIES WILL EXPIRE AT 515 PM
CDT...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning will be allowed to expire.

LAT...LON 3933 9227 3931 9215 3901 9192 3897 9232
      3924 9234 3925 9233 3925 9231 3928 9231
TIME...MOT...LOC 2214Z 335DEG 24KT 3910 9215 

$$

Gosselin

Area Forecast Discussion
National Weather Service Saint Louis MO
347 PM CDT Sun May 6 2018

.SHORT TERM...  (Through Late Monday Afternoon)
Issued at 223 PM CDT Sun May 6 2018

A cold front over northeast and central Missouri and western
Illinois will continue to move through the area this afternoon.
The upper level forcing along and ahead of the front continues to
not look all that impressive this afternoon. The latest run of
convective allowing models show isolated showers and thunderstorms
over the area this afternoon into early this evening along and
ahead of the front. A strong thunderstorm or two is possible this
afternoon over portions of southeast Missouri where bulk shear
values are between 25 to 30 knots, while bulk shear values
elsewhere are 20kts or less. Additionally, there is roughly 1000
to 1500 J/kg of surface based CAPE over the area. The cold front
will exit the forecast area by late this evening allowing for
skies to clear from northwest to southeast. High pressure will
move into the area from the Great Lakes region overnight. Lows
tonight will be in the lower 50s across the area.

The weather will be dry with light northeast winds on Monday as
high pressure remains in control over the area. Highs will be in
the 70s across the area for Monday.

Kelly

.LONG TERM...  (Monday Night through Next Sunday)
Issued at 223 PM CDT Sun May 6 2018

The aforementioned high pressure center over the Great Lakes will
ensure that quiet weather and seasonably cool temperatures
continue for Monday night. Meanwhile, one PV anomaly will move
into the northern plains while a separate PV anomaly begins diving
southeastward out of BC/AB towards MT. Some models hint at a
third disturbance across the central plains, but it is not clear
whether this feature is real or the result of convective feedback.

Regardless, at least two PV anomalies will interact over the
northern plains and upper midwest during the middle of the week,
yielding a low pressure system with a trough axis extending
southward into MO/IL. This system will bring a period of unsettled
weather to the LSX CWA from Tue night through the first half of
Wed night. A LLJ will initially impinge on a developing warm
frontal boundary, and the resulting H85 moisture convergence as
well as large-scale ascent ahead of the approaching upper trough
axis will support an area of SHRA/TSRA which moves across the area
on Tue night in tandem with the lifting warm frontal boundary
aloft. Increasing diurnal instability on Wed along with large-
scale ascent ahead of the approaching upper PV anomaly should
produce additional SHRA/TSRA on Wed aftn/eve.

Increasing surface dew points on Wed as well as steep H7-H5 lapse
rates of 6-7.5 deg C/km will contribute to moderate instability,
and a few strong to severe thunderstorms will be possible on Wed
aftn/eve based on the instability alone. In addition to the
instability, there may be between 20-40 kts of 0-6km bulk shear
available to aid in storm organization, but the shear forecast has
been inconsistent between models. The entire low pressure system
should be east of the area between 06-12z Thu, leading to lower
precipitation chances for the first half of Thu. It is not yet
clear how far south the trailing cold front will progress on Thu
before another wave of low pressure develops along the baroclinic
zone and acts to lift it back northwards, and low precipitation
chances have been retained across parts of the area for Thu aftn
through late Fri night. The location of this boundary will also
be important for the next low pressure system (described below),
but uncertainty remains high at this time.

Models depict a closed low pressure system developing over the
intermountain west and/or the four corners region by Fri/Sat, but
there are significant differences regarding the evolution and
speed of this feature. It is reasonable to expect that this system
would bring a chance of SHRA/TSRA to the area late when it lifts
into the central CONUS late next weekend and early next week, but
there is high uncertainty at this time due to poor model
agreement and poor run-to-run continuity.

Temperatures will gradually increase this week, starting with a
slight boost to highs on Tue after the Great Lakes high pressure
center has shifted eastward and winds acquire a more southerly
component. The warmest temperatures are expected later this week
and early next weekend when the combination of persistent southerly
winds and rising heights aloft helps boost highs into the low/mid
80s.

Kanofsky

&&

.AVIATION...  (For the 18z TAFs through 18z Monday Afternoon)
Issued at 1229 PM CDT Sun May 6 2018

Cold front over central and northeast Missouri and western
Illinois will continue to slowly push east this afternoon and
evening. Scattered showers and thunderstorms will redevelop along
and ahead of the front this afternoon. The front should clear the
area by this evening. VFR conditions can be expected outside of
the showers and thunderstorms this afternoon. A brief period of
MVFR conditions with any shower or thunderstorm. The sky will
clear this evening from northwest to southeast this evening. A
west- southwest surface wind this afternoon will veer to a
northwest direction after FROPA, then north-northeast direction
this evening as a surface ridge will build into the area from the
Great Lakes.

SPECIFICS FOR KSTL: Cold front over central and northeast Missouri
and western Illinois will pass over the terminal this afternoon.
Scattered showers and thunderstorms will develop within the
vicinity of the terminal this afternoon. VFR conditions can be
expected through Monday afternoon outside of showers and
thunderstorms this afternoon. A brief period of MVFR is possible
with any shower or thunderstorm that moves over the terminal. A
west- southwest surface wind will veer this afternoon after FROPA
to a northwest direction, then north- northeast direction this
evening as a surface ridge builds into the area from the Great
Lakes region.

Kelly

&&

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

WFO LSX

Hazardous Weather Outlook
National Weather Service Saint Louis MO
349 PM CDT Sun May 6 2018

ILZ058>060-064-065-069-070-074-079-095>102-MOZ018-019-026-027-
034>036-041-042-047>052-059>065-072>075-084-085-099-071200-
Greene IL-Macoupin IL-Montgomery IL-Bond IL-Fayette IL-Clinton IL-
Marion IL-Washington IL-Randolph IL-Adams IL-Brown IL-Pike IL-
Calhoun IL-Jersey IL-Madison IL-Saint Clair IL-Monroe IL-Knox MO-
Lewis MO-Shelby MO-Marion MO-Monroe MO-Ralls MO-Pike MO-Boone MO-
Audrain MO-Moniteau MO-Cole MO-Osage MO-Callaway MO-Montgomery MO-
Lincoln MO-Gasconade MO-Warren MO-Saint Charles MO-Franklin MO-
Saint Louis MO-Saint Louis City MO-Jefferson MO-Crawford MO-
Washington MO-Saint Francois MO-Sainte Genevieve MO-Iron MO-
Madison MO-Reynolds MO-
349 PM CDT Sun May 6 2018

This hazardous weather outlook is for portions of eastern and
central Missouri as well as west central and southwest Illinois.

.DAY ONE...Late afternoon and tonight

Scattered thunderstorms have developed this afternoon and are
expected to persist into the early evening. A few storms could be
strong enough to produce gusty winds and small hail.

.DAYS TWO THROUGH SEVEN...Monday through Saturday

There is a chance of thunderstorms from Tuesday night through
Saturday. A few strong to severe storms are possible on Wednesday
afternoon and evening.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not anticipated tonight.

Kanofsky