Tornadoes and Hail in Missouri, June 28, 2015

AREA FORECAST DISCUSSION...UPDATED AVIATION
NATIONAL WEATHER SERVICE ST LOUIS MO
106 PM CDT Sun Jun 28 2015

.UPDATE:
Issued at 1220 PM CDT Sun Jun 28 2015

Some adjustments to PoPs throughout the morning and into the
afternoon, as expect WAA-induced band of showers and thunderstorms
to persist and slowly weaken as it moves east. Additional
development will also occur over the CWA as increasing unstable
air over western MO advects east and interacts with rain-cooled
dome of air, while large scale ascent increases with approaching...and
strong...upper level vort max. In this NW flow regime, expect that
the intense storm development should be fairly rapid.

Truett

&&

.SHORT TERM:  (Through Late Tonight)
Issued at 312 AM CDT Sun Jun 28 2015

Area of showers and thunderstorms over northern Iowa will continue
to move southeast this morning and may affect areas north of I-70
as it will be supported by continued low level moisture convergence
per latest runs of the RAP. Then still expect thunderstorms to
move southeast across the area today as shortwave trough currently
over Minnesota and the eastern Dakotas will dip down into the CWA
by 06Z this evening. This will cause strong ascent to move into
the area during the afternoon and evening hours. Thunderstorms
should develop ahead of cold front this afternoon over northeast
Missouri and west central Illinois and move southeast to near I-70
by this evening. These thunderstorms will move out of the eastern
and southern parts of the CWA between 06-12Z tonight when the
upper trough and the low level forcing shifts out of the CWA. This
scenario is backed up by the latest 00Z run of NMM-HRRR. A few
severe thunderstorms still look possible today as MLCAPES will be
in the 1000-2000 J/kg range this afternoon and this evening with
0-6km shear values near 40kts favoring organized multicells and
some supercells.

Temperatures will be warmer today ahead of the cold front with
mixing up to near 800mb.

.LONG TERM: (Monday through Saturday)
Issued at 312 AM CDT Sun Jun 28 2015

(Monday and Tuesday)

Still looks like there will be a few isolated thunderstorms
redevelop on Monday over parts of northeast Missouri into west
central and south central Illinois as the atmosphere becomes
unstable once again with another weak shortwave trough moving across
the area. Will continue with the chance PoPs on Tuesday and
Tuesday night as atmosphere will be even more unstable with
another, more notable trough moving through the area in
northwesterly flow aloft.

Highs will be well continue to be in the 80s has mixing will be in
the 800-850mb range.

(Wednesday through Saturday)

There will continued to be an amplified upper pattern over the CONUS
with a series of shortwaves digging southward into Missouri and
Illinois during the period which will keep a chance of showers and
thunderstorm going during this period. Wavy front will be over the
area which will help be a focus for storm development. Rain
chances and 850mb temperatures around 15C favor below normal
temperatures.

Britt

&&

.AVIATION:  (For the 18z TAFs through 18z Monday Afternoon)
Issued at 105 PM CDT Sun Jun 28 2015

Expect rapid storm development in the 20-22z time frame as UVV
associated upper level shortwave over eastern IA drops south and interacts
with low level WAA of increasinginly unstable airmass over our
CWA. TAFs reflect a first estimate of timing and intensity
(primarily IFR vsbys/MVFR cigs) at each location, which will be
updated once convection shows its hand. Current indications are
that convection should also shut down rapidly during the early
evening hours, with tranquil VFR conditions.

Specifics for KSTL: Clouds aoa 5kft and scattered showers are
anticipated early this afternoon, with increasing threat of
intense thunderstorms (IFR vsbys/MVFR cigs) in the 22-00z time
frame due to features mentioned in the primary AFD discussion.
Storms should rapidly sweep southeast of the area during the early
evening hours, with VFR conditions/clear skies for the remainder
of the overnight hours.

Truett

&&

.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&

WFO LSX

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE ST LOUIS MO
418 AM CDT SUN JUN 28 2015

ILZ058>060-064-065-069-070-074-079-095>102-MOZ018-019-026-027-
034>036-041-042-047>052-059>065-072>075-084-085-099-290930-
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-ST. 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-ST. CHARLES MO-FRANKLIN MO-
ST. LOUIS MO-ST. LOUIS CITY MO-JEFFERSON MO-CRAWFORD MO-
WASHINGTON MO-ST. FRANCOIS MO-STE. GENEVIEVE MO-IRON MO-
MADISON MO-REYNOLDS MO-
418 AM CDT SUN JUN 28 2015

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF EASTERN AND
CENTRAL MISSOURI AS WELL AS WEST CENTRAL AND SOUTHWEST ILLINOIS.

.DAY ONE...TODAY AND TONIGHT

THE NORTH...MIDDLE AND SOUTH FABIUS RIVERS...THE CUIVRE RIVER AT OLD
MONROE...THE MISSISSIPPI RIVER AT QUINCY...QUINCY LOCK AND DAM
21...AND SAVERTON LOCK AND DAM 22 AS WELL AS POINTS ALONG THE
ILLINOIS RIVER ARE CURRENTLY IN MAJOR FLOOD STAGE.

THUNDERSTORMS ARE LIKELY TODAY AND TONIGHT. A FEW OF THESE STORMS
MAY BECOME SEVERE THIS AFTERNOON AND THIS EVENING...WITH THE
POSSIBILITY OF LARGE HAIL...DAMAGING WIND GUSTS AND TORNADOES.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

POINTS ALONG THE ILLINOIS RIVER WILL CONTINUE TO BE IN MAJOR FLOOD
THROUGH AT LEAST THE 4TH OF JULY WEEKEND. THE CUIVRE RIVER AT OLD
MONROE AS WELL AS THE NORTH...MIDDLE AND SOUTH FABIUS RIVERS ARE
EXPECTED TO CONTINUE TO EXCEED MAJOR FLOOD STAGE THROUGH MONDAY.
MAJOR FLOODING IS FORECAST ALONG THE MISSISSIPPI RIVER AT WINFIELD
LOCK AND DAM 25...GRAFTON AND CHESTER OVER THE NEXT FEW DAYS.

THE CHANCE FOR THUNDERSTORMS CONTINUES OVER PARTS OF THE AREA THROUGH
SATURDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS POSSIBLE.

BRITT