DAY1SVR: Day 1 Convective Outlook

ACUS01 KWNS 041632
SWODY1
SPC AC 041630

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1130 AM CDT MON JUN 04 2012

VALID 041630Z - 051200Z

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE LOWER OH
VALLEY/MIDWEST ACROSS THE SOUTH/SOUTHEAST...

...THERE IS A SLGT RISK OF SVR TSTMS OVER PARTS OF THE SRN PLAINS
AND ADJACENT HIGH PLAINS...

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE INTERIOR NORTHWEST
ACROSS THE CONTINENTAL DIVIDE TO MT HIGH PLAINS...

...SOUTH AND SOUTHEAST...
MCS ACROSS AL/GA HAS WEAKENED THROUGH THE MORNING AND RENEWED
CONVECTIVE DEVELOPMENT HAS OCCURRED ON ITS FLANK...ACROSS WRN TN AND
NRN MS. STORMS NOW ACROSS NRN MS MAY BE AIDED BY LIFT ASSOCIATED
WITH A WELL-DEFINED MCV OVER AR AND ARE LIKELY ROOTED ABOVE A CAPPED
BOUNDARY LAYER. A BELT OF 40-50KT MID LEVEL FLOW IS OBSERVED IN VWP
DATA...COINCIDENT WITH AREAS OF CONVECTION AND/OR RADAR ECHOES
ASSOCIATED WITH CONVECTIVE DEBRIS. THIS STRONGER FLOW EXISTS FROM AR
EAST TO SC WHILE VISIBLE IMAGERY CONTINUES TO DEPICT NEARLY
CLOUD-FREE CONDITIONS TO THE SOUTH OF THE CONVECTION AND STRONGER
DEEP-LAYER SHEAR.

THERE REMAINS SOME POTENTIAL FOR STRONGER SURFACE-BASED UPDRAFTS TO
EVOLVE AS BOUNDARY LAYER WARMS THROUGH THE AFTERNOON FROM AL ACROSS
SRN GA AND EXTREME SRN SC. LIFT ALONG THE CONVECTIVE COLD POOL AND
DIFFERENTIAL HEATING ZONE...IN CONCERT WITH WEAK MCV ACROSS AL
SHOULD...SHOULD SUPPORT AN INCREASE IN SEVERE HAIL/WIND POTENTIAL AS
THE CONVECTION SPREADS ESEWD THIS AFTERNOON. GIVEN THE WEAKENING
TRENDS THROUGH THE MORNING...IT IS UNCERTAIN WHETHER THIS SEVERE
POTENTIAL WILL BECOME ALL THAT WIDESPREAD OR REMAIN ISOLATED IN
CHARACTER.

ANOTHER MCS MAY ALSO TAKE FORM OUT OF THE ELEVATED CONVECTION
ACROSS NRN MS. IN ADDITION TO DIURNAL DESTABILIZATION...INCREASE IN
THIS ACTIVITY MAY BE FURTHER SUPPORTED BY AFOREMENTIONED MCV ACROSS
AR. UNCERTAINTY EXISTS REGARDING THE EVOLUTION IN THIS FLANKING MCS
AS INHIBITION AND SHEAR ARE SOMEWHAT LESS SUPPORTIVE OF ORGANIZED
STORMS WITH WWD EXTENT TOWARD THE LOWER MS VALLEY.

...MT EAST OF THE DIVIDE/HIGH PLAINS...
A WARM FRONT EXTENDING W-E FROM THE NRN GREAT BASIN ACROSS NRN
WY/SRN MT WILL ADVANCE NWD WHILE SFC LOW PRESSURE INTENSIFIES ACROSS
WRN ID IN RESPONSE TO INCREASING LARGE-SCALE ASCENT IN ADVANCE OF AN
APPROACHING/AMPLIFYING EAST-PACIFIC SHORTWAVE TROUGH. WAA NORTH OF
THE FRONT CONTINUES TO SUPPORT ACCAS AND ISOLATED SHOWERS/STORMS
WITHIN AN ARC FROM E-CNTRL ID ACROSS CNTRL/N-CNTRL MT AND INTO SERN
MT. THE WAA AMPLIFY THE DOWNSTREAM RIDGE...WHOSE AXIS CURRENTLY LIES
N-S OVER THE NRN HIGH PLAINS WITH THE RIDGE AXIS SHIFTING EWD
THROUGH THE PERIOD.

HEIGHT FALLS LEADING THE AFOREMENTIONED SHORTWAVE TROUGH
ARE NOT FORECAST TO COMMENCE IN EARNEST UNTIL LATE TONIGHT...MAINLY
AFFECTING SWRN MT.

AS THE WARM FRONT EMERGES OVER THE HIGH PLAINS OF CNTRL/ERN MT...IT
WILL BECOME BETTER DEFINED AS WEAK LEE CYCLOGENESIS OCCURS OVER
CNTRL MT. RELATIVELY RICHER LOW-LEVEL MOISTURE IS ANTICIPATED NEAR
AND NORTH OF THE WARM FRONT...WHERE SFC DEWPOINTS MAY HOLD IN THE
50S...ESPECIALLY ACROSS CNTRL/N-CNTRL MT. EVEN STRONGER VERTICAL
MIXING SOUTH OF THE FRONT WITHIN THE DEEPER BOUNDARY LAYER MAY YIELD
SOMEWHAT LOWER DEWPOINTS FARTHER SOUTH TOWARD SWRN MT. AND...WITH
STRONG SFC HEATING...MLCAPE VALUES OF 750-1500 J/KG SHOULD DEVELOP
ACROSS A LARGE PART OF MT...HIGHEST IN AREAS REMOVED FROM CLOUD
COVER. SWRN MT MOUNTAINS ALSO SERVE AS ELEVATED HEAT SOURCES...AND
PROVIDE A ZONE OF CONVECTIVE INITIATION BETWEEN 21Z AND 23Z.

STORMS WILL TRACK QUICKLY NNEWD/NEWD ACROSS THE NRN ROCKY MOUNTAIN
FRONT AND ADJACENT HIGH PLAINS OF CNTRL/N-CNTRL MT INTO THE EARLY
EVENING. OTHER STORMS MAY DEVELOP ACROSS THE MOUNTAINS SW/W OF
BILLINGS BY LATE AFTERNOON AND TRACK SIMILAR TO THOSE FARTHER
WEST...THOUGH INITIATION IS NOT AS CERTAIN FARTHER EAST UNDER THE
MID-LEVEL RIDGE AXIS.

GIVEN STRONG MID-LEVEL FLOW SUPPORTING 45-55 KT OF DEEP
SHEAR...JUXTAPOSED WITH THE AFOREMENTIONED BUOYANCY...PERSISTENT
SUPERCELL STRUCTURES WILL BE POSSIBLE /POSSIBLY EVOLVING INTO BOWING
LINE SEGMENTS/...ESPECIALLY WITH CONVECTION ACROSS CNTRL/N-CNTRL MT
NEAR AND NORTH OF THE WARM FRONT. SVR WIND/HAIL WILL BE OF CONCERN
WITH THESE STORMS...AND SOME SIGNIFICANTLY SVR WIND WILL BE
POSSIBLE. A TORNADO THREAT MAY ALSO DEVELOP WITH THE
STRONGEST/MOST PERSISTENT SUPERCELLS NEAR AND NORTH OF THE
FRONT...EAST OF THE FRONT RANGE TOWARD GREAT FALLS AND HAVRE. BACKED
SFC WINDS IN THESE AREAS WILL SUPPORT THE GREATEST LOW-LEVEL
HODOGRAPH CURVATURE.

WHILE ADDITIONAL STORMS COULD MOVE INTO THE AREA FROM THE WEST LATER
TONIGHT AS STRONGER DEEP FORCING FOR ASCENT ARRIVES...CINH OWING TO
THE INCREASINGLY STABLE NOCTURNAL BOUNDARY LAYER WILL LIKELY
MITIGATE THE SVR THREAT...THOUGH SOME HAIL CANNOT BE RULED OUT WITH
THE STRONGEST STORMS LATE TONIGHT IF THEY CROSS THE CONTINENTAL
DIVIDE.

...INTERIOR NW/WEST OF THE DIVIDE...
LARGE-SCALE FORCING FOR ASCENT WILL CONTINUE TO INCREASE IN
ADVANCE OF APPROACHING EAST-PACIFIC SHORTWAVE TROUGH. STORMS SHOULD
DEVELOP OVER THE HIGHER TERRAIN OF ERN ORE AND
W-CNTRL ID BEFORE MOVING QUICKLY NNEWD ACROSS ERN WA AND NWRN ID
NEAR AND AHEAD OF THE FRONT ATTENDANT TO THE SHORTWAVE TROUGH.
SFC HEATING WILL ALLOW FOR POCKETS OF MARGINAL TO MODERATE
DESTABILIZATION AS PACIFIC MOISTURE CROSSES THE REGION. STRONG
MERIDIONAL FLOW WILL SUPPORT EFFECTIVE BULK SHEAR MAGNITUDES IN
EXCESS OF 50 KT...WITH SUPERCELLS AND BOWING LINE SEGMENTS LIKELY
EVOLVING THROUGH THE LATE AFTERNOON INTO THE EVENING. WHERE SFC
WINDS REMAIN RELATIVELY MORE BACKED NEAR A NWD-ADVANCING WARM FRONT
FROM ERN ID AND WRN MT AND ACROSS REGIONS OF TERRAIN-CHANNELED
FLOW...A TORNADO CANNOT BE COMPLETELY RULED OUT. INCREASING CINH
AFTER DARK SHOULD SERVE TO LIMIT OVERALL SVR
POTENTIAL.

...SRN HIGH PLAINS/W TX TO RED RIVER...
RESIDUAL DEEP-LAYER FRONTAL ZONE WAS FRAGMENTED BY NUMEROUS STORM
CLUSTERS/OUTFLOWS FROM WRN AR/SRN OK WWD ACROSS NWRN TX AND INTO THE
SRN HIGH PLAINS. THIS ENTIRE REGION LIES BENEATH WEAK AND VARIABLE
MID LEVEL FLOW ON THE ORDER OF 10-20KT AND GENERALLY AMBIGUOUS
INDICATIONS FOR LARGE SCALE ASCENT. STRONG HEATING AND ABUNDANT
MOISTURE WILL AGAIN CONTRIBUTE TO THE DEVELOPMENT OF WEAKLY CAPPED
MODERATE TO STRONG INSTABILITY ACROSS MUCH OF THE REGION THIS
AFTERNOON. POST-FRONTAL UPSLOPE FLOW AND DIFFERENTIAL HEATING ACROSS
THE HIGHER TERRAIN WILL RESULT IN STORM INITIATION ACROSS CO/NM
DURING THE AFTERNOON. ADDITIONAL DEVELOPMENT APPEARS POSSIBLE ALONG
THE DECAYING FRONTAL/OUTFLOW SEGMENT...SOUTH OF THE RED RIVER...BY
LATE IN THE DAY OR EARLY EVENING. WHILE ALL OF THIS CONVECTION WILL
OCCUR AMIDST GENERALLY WEAK FLOW...MAGNITUDE OF AVAILABLE
INSTABILITY...A DEEPLY MIXED/HOT BOUNDARY LAYER...AND BOUNDARY/STORM
INTERACTIONS...CAN COMPENSATE FOR LACK OF STRONGER SHEAR TO SUPPORT
SCATTERED SEVERE STORMS WITH HAIL AND HIGH WINDS.

...ERN MO/SRN IL TO WRN TN...
AN ASSORTMENT OF DETERMINISTIC/CONVECTION ALLOWING GUIDANCE ARE
SUGGESTIVE OF SCATTERED POTENTIALLY STRONG/SEVERE TSTM DEVELOPMENT
BY MID/LATE AFTERNOON WITHIN A NNW-SSE CORRIDOR ACROSS THE REGION.
AMID AMPLIFYING NORTHWESTERLY FLOW ALOFT...THIS WOULD BE IN VICINITY
OF A WEAK SURFACE LOW/ASSOCIATED FRONTAL BOUNDARY. AMPLE MOISTURE
AND HEATING ON THE SOUTHWEST EDGE OF A MORNING CLOUD DECK ACROSS
IL/INDIANA WILL ALLOW FOR MODERATE DESTABILIZATION WITH 2000-3500
J/KG MLCAPE ALONG/SOUTHWEST OF THE FRONT. AIDED BY MODERATELY STRONG
NORTHWESTERLY FLOW ALOFT /MAXIMIZED ALONG AND NORTHEAST OF THE
FRONT/...STORMS SHOULD TRACK SOUTHEASTWARD THROUGH LATE AFTERNOON
AND EVENING ACROSS THE MIDDLE MS VALLEY INCLUDING THE MO BOOTHEEL
VICINITY AND WESTERN PORTIONS OF KY/TN WHILE POSING A RISK FOR
DAMAGING WINDS/SEVERE HAIL.

...SRN FL...
VERY SMALL AREA OF S FL...IMMEDIATELY NEAR EAST COAST SEA
BREEZE...MAY SEE DEVELOPMENT OF VIGOROUS DEEP CONVECTION THIS
AFTERNOON. A WET MICROBURST OR SMALL HAIL EVENT CANNOT BE COMPLETELY
RULED OUT.

..CARBIN/GUYER/COHEN.. 06/04/2012

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