DAY1SVR: Day 1 Convective Outlook

ACUS01 KWNS 232003
SWODY1
SPC AC 232000

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0300 PM CDT SUN JUN 23 2013

VALID 232000Z - 241200Z

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE CENTRAL
PLAINS AND MIDDLE MISSISSIPPI VALLEY INTO THE UPPER GREAT LAKES
REGION...

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE LOWER GREAT
LAKES INTO NORTHERN NEW ENGLAND...

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF EASTERN ND AND
NORTHERN MN...

...EASTERN ND/NORTHERN MN...
GIVEN CLOUD COVER/WEAK CONVERGENCE...SEVERE POTENTIAL APPEARS TO
LOW/DIMINISHING NEAR UPPER VORT MAX CROSSING ND THIS AFTERNOON.
NONETHELESS...SOME POTENTIAL FOR GUSTY WINDS/SOME HAIL MAY REMAIN
PENDING ADDITIONAL DESTABILIZATION ACROSS AREAS SUCH AS FAR EASTERN
ND INTO NORTHWEST MN.

...SOUTHERN HIGH PLAINS...
AT LEAST ISOLATED/PERHAPS WIDELY SCATTERED TSTMS CAPABLE OF SEVERE
WIND/HAIL WILL BE POSSIBLE BY LATE AFTERNOON ACROSS PARTS OF
WEST/SOUTHWEST TX.

...ELSEWHERE...
SEE PRIOR OUTLOOK DISCUSSION BELOW...MESOSCALE DISCUSSIONS 1187/1188
FOR THE MIDWEST...AS WELL AS SUBSEQUENT MESOSCALE DISCUSSIONS.

..GUYER.. 06/23/2013

.PREV DISCUSSION... /ISSUED 1129 AM CDT SUN JUN 23 2013/

...SYNOPSIS...
MODELS INDICATE THAT MID-LEVEL SUBTROPICAL RIDGING WILL BUILD ACROSS
MUCH OF THE SOUTH CENTRAL AND SOUTHEASTERN STATES TODAY. AS THIS
OCCURS...THE SIGNIFICANT SHORT WAVE IMPULSE...NOW OVER THE NORTHERN
PLAINS...IS EXPECTED TO CONTINUE PIVOTING NORTHWARD INTO SOUTHERN
MANITOBA AND NORTHWEST ONTARIO...BEFORE TURNING EASTWARD
ACROSS/NORTH OF THE UPPER GREAT LAKES REGION. PREVAILING MID-LEVEL
FLOW WILL BECOME BROADLY ANTICYCLONIC EAST OF THE ROCKIES THROUGH
THE NORTHERN PLAINS AND UPPER MISSISSIPPI VALLEY INTO THE
NORTHEAST...JUST TO THE SOUTHWEST OF A LARGE AND DEEP CLOSED LOW
DIGGING ACROSS PARTS OF NORTHERN QUEBEC AND THE CANADIAN MARITIMES.
MEANWHILE...MODEST CYCLONIC FLOW IS EXPECTED TO DEVELOP INLAND
ACROSS THE PACIFIC COAST THROUGH THE ROCKIES...AHEAD OF A STRONG
NORTHWESTERLY MID/UPPER JET DIGGING ACROSS THE MID LATITUDE EASTERN
PACIFIC.

VERY STEEP MID-LEVEL LAPSE RATES ASSOCIATED WITH ELEVATED MIXED
LAYER AIR EMANATING FROM THE GREAT BASIN/ROCKIES...APPEAR TO HAVE
GENERALLY BECOME CONFINED TO PORTIONS OF THE CENTRAL AND SOUTHERN
PLAINS. BUT...ELEVATED MIXED LAYER AIR...BASED AT LOWER
LEVELS...HAS ADVECTED ALONG WITH INCREASING LOW-LEVEL
MOISTURE...AROUND THE LOWER/MID-LEVEL RIDGING...FROM THE PLAINS
THROUGH THE GREAT LAKES REGION INTO PARTS OF THE NORTHEAST.
ASSOCIATED DESTABILIZATION IS EXPECTED TO CONTRIBUTE TO AN
INCREASING RISK FOR THUNDERSTORMS ACROSS PARTS OF THE LOWER GREAT
LAKES REGION AND NORTHEAST TODAY...WHILE THE RISK FOR THUNDERSTORMS
CONTINUES ACROSS PARTS OF THE PLAINS INTO THE UPPER MISSISSIPPI
VALLEY AND UPPER GREAT LAKES.

GIVEN CONTINUING WEAK MID-LEVEL INHIBITION ACROSS THE
SOUTHEAST...DAYTIME HEATING OF A MOIST BOUNDARY LAYER WILL
CONTRIBUTE TO CONSIDERABLE THUNDERSTORM ACTIVITY ACROSS THE CENTRAL
AND SOUTHERN APPALACHIANS INTO GULF AND SOUTH ATLANTIC COASTAL
AREAS. OTHER ISOLATED TO SCATTERED LATE AFTERNOON AND EVENING STORM
DEVELOPMENT IS NOT OUT OF THE QUESTION FROM THE CASCADES INTO THE
NORTHERN INTERMOUNTAIN REGION.

...UPPER MISSISSIPPI VALLEY/UPPER GREAT LAKES REGION...
STABILIZATION OF MID-LEVEL LAPSE RATES FROM CONVECTION OF THE PAST
FEW DAYS...AND LOWER LEVEL STABILIZATION ASSOCIATED WITH CONVECTION
OVERNIGHT...COUPLED WITH THE ONSET OF MID-LEVEL HEIGHT RISES IN THE
WAKE OF THE UPPER IMPULSE...APPEARS TO LOWER SEVERE PROBABILITIES
ACROSS MUCH OF THE REGION. HOWEVER...DAYTIME HEATING COULD STILL
CONTRIBUTE TO SUFFICIENT DESTABILIZATION FOR AT LEAST A MARGINAL
SEVERE THREAT AHEAD OF THE EASTWARD ADVANCING CONVECTIVE OUTFLOW
BOUNDARY SPREADING INTO PARTS OF THE UPPER PENINSULA OF
MICHIGAN...EASTERN WISCONSIN...EASTERN IOWA AND NORTHWESTERN
ILLINOIS.

IT ALSO DOES NOT APPEAR OUT OF THE QUESTION THAT AS STRONGER
MID/UPPER FORCING FOR UPWARD VERTICAL MOTION DEVELOPS ACROSS THE
INTERNATIONAL BORDER AREA LATE THIS AFTERNOON...DESTABILIZATION IN
THE WAKE OF EARLY DAY CLOUD COVER/PRECIPITATION COULD BECOME
SUFFICIENT TO SUPPORT A RISK FOR SEVERE STORMS. DEEP LAYER SHEAR
WILL BECOME STRONG...NEAR AN ASSOCIATED 50+ KT 500 MB JET NOSING
ACROSS NORTHERN MINNESOTA.

...CENTRAL ROCKIES INTO THE CENTRAL PLAINS...
BENEATH STEEP MID-LEVEL LAPSE RATES...LARGE MIXED LAYER CAPE IS
EXPECTED TO DEVELOP ALONG A REMNANT COMPOSITE OUTFLOW BOUNDARY
ACROSS NORTHERN KANSAS...AND...BY LATE THIS AFTERNOON OR EVENING
...WITHIN A DEVELOPING UPSLOPE FLOW REGIME TO THE EAST OF THE FRONT
RANGE OF THE ROCKIES. VEERING WIND PROFILES WITH HEIGHT... FROM AN
EASTERLY COMPONENT AT LOW-LEVELS TO MODEST WESTERLIES ALOFT...WILL
BE SUPPORTIVE OF SUPERCELLS...AND PERHAPS OF THE UPSCALE GROWTH OF A
SEVERE STORM CLUSTER...ACROSS NORTHEAST COLORADO AND ADJACENT AREAS
OF THE HIGH PLAINS THIS EVENING. SUPERCELLS...AND THE EVENTUAL
EVOLUTION OF A LARGE CLUSTER OF STORMS...ALSO APPEARS POSSIBLE
ACROSS PARTS OF NORTH CENTRAL AND NORTHEAST KANSAS...AND ADJACENT
AREAS OF SOUTHERN NEBRASKA/NORTHWEST MISSOURI. THIS IS WHERE A
MODERATE TO STRONG SOUTHERLY LOW-LEVEL JET MAY FOCUS FORCING FOR
UPWARD VERTICAL MOTION BY EARLY EVENING.

...LOWER GREAT LAKES INTO NORTHERN NEW ENGLAND...
MODERATELY LARGE CAPE IS EXPECTED TO DEVELOP WITH DAYTIME HEATING OF
A MOIST BOUNDARY LAYER. FORCING FOR CONVECTIVE DEVELOPMENT REMAINS
A BIT UNCLEAR...BUT A NARROW BELT OF 20-30 KT WESTERLY DEEP LAYER
MEAN FLOW...ACROSS UPSTATE NEW YORK INTO NEW ENGLAND...COULD ENHANCE
THE POTENTIAL FOR ONE OR TWO SMALL FORWARD PROPAGATING CLUSTERS OF
STORMS CAPABLE OF PRODUCING POTENTIALLY DAMAGING WIND GUSTS.

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
To unsubscribe from WX-STORM send e-mail to LISTSERV@LISTSERV.ILLINOIS.EDU with
"unsub wx-storm" in the body of your message. For more information write cnovy@cox.net.