SPC Day 2 Outlook
DAY 2 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
1230 PM CDT WED MAY 06 2015
VALID 071200Z - 081200Z
...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE CENTRAL/SOUTHERN
PLAINS...
...THERE IS A MRGL RISK OF SVR TSTMS FROM THE SOUTHERN PLAINS TO THE
UPPER MIDWEST...
...THERE IS A MRGL RISK OF SVR TSTMS ACROSS PORTIONS OF NV/UT...
...SUMMARY...
SEVERE THUNDERSTORMS WILL BE POSSIBLE THURSDAY FROM PORTIONS OF THE
SOUTHERN AND CENTRAL PLAINS NORTHEASTWARD INTO THE UPPER MIDWEST.
...SYNOPSIS...
RELATIVELY LIMITED LARGE-SCALE PATTERN FLUCTUATION WILL OCCUR OVER
THE CONUS ON THURSDAY. AN INCREASINGLY CLOSED UPPER LOW OVER THE
PACIFIC NORTHWEST WILL SHIFT SOUTH-SOUTHWESTWARD OVER THE GREAT
BASIN/CA ON THURSDAY...WHILE ONE OR MORE SHORTWAVE
TROUGHS/CONVECTIVELY RELATED DISTURBANCES MOVE NORTHEASTWARD OVER
THE CENTRAL/SOUTHERN PLAINS TO UPPER MIDWEST AMID A MODERATELY
STRONG BRANCH OF SOUTHWESTERLY FLOW ALOFT. A COLD FRONT WILL SPREAD
EASTWARD OVER THE UPPER MIDWEST/MIDDLE MO VALLEY THROUGH THURSDAY
NIGHT...WHILE A DRYLINE WILL EXTEND GENERALLY SOUTHWARD ACROSS WEST
TX/FAR WESTERN OK FROM A SOUTH-CENTRAL HIGH PLAINS SURFACE LOW.
...CENTRAL/SOUTHERN PLAINS...
MORNING SHOWERS/SOME EMBEDDED THUNDERSTORMS AND RELATED CLOUD COVER
WILL LIKELY BE FACTORS THURSDAY MORNING ACROSS PORTIONS OF KS/OK
INTO NORTH TX. ON THE WESTERN FRINGE OF THIS EARLY DAY ACTIVITY...AN
ELEVATED MIXED LAYER/PLUME OF STEEP MID-LEVEL LAPSE RATES WILL
QUICKLY BECOME REESTABLISHED ATOP A RELATIVELY MOIST AIR MASS WITH
60S F SURFACE DEWPOINTS COMMON TO THE EAST OF A SOUTHERN HIGH PLAINS
DRYLINE/SURFACE TRIPLE POINT AND TO THE SOUTHEAST OF A SLOW
SOUTHEASTWARD-MOVING FRONT ACROSS NORTHERN KS/EASTERN NEB. SCENARIO
SHOULD LEAD TO AT LEAST MODERATE DESTABILIZATION WITH UPWARDS OF
2500-3500 J/KG MLCAPE PLAUSIBLE BY MID-AFTERNOON PARTICULARLY ACROSS
WEST-CENTRAL/NORTH-CENTRAL TX INTO EASTERN TX PANHANDLE/WESTERN OK
AND WESTERN/NORTHERN KS.
LARGER-SCALE FORCING FOR ASCENT WILL BE RELATIVELY MODEST...BUT THE
LEFT-EXIT REGION OF AN APPROACHING SOUTHERN STREAM JET AND THE
INFLUENCE OF MODERATELY STRONG CYCLONIC WESTERLIES...ALONG WITH
STRONG HEATING/SUFFICIENT CONVERGENCE...SHOULD CONTRIBUTE TO AT
LEAST ISOLATED DEEP CONVECTIVE INITIATION BY MID/LATE AFTERNOON.
INITIAL DEEPER CONVECTIVE DEVELOPMENT MAY OCCUR ACROSS EASTERN CO BY
MID/LATE AFTERNOON VIA A POST-FRONTAL UPSLOPE REGIME...WITH
ADDITIONAL DEVELOPMENT BY LATE AFTERNOON/EARLY EVENING NEAR THE
DRYLINE ACROSS THE TX/OX PANHANDLES AND NEAR THE TRIPLE
POINT/ADJACENT FRONT ACROSS WESTERN/NORTHERN KS.
GIVEN AFOREMENTIONED BUOYANCY...DEEP-LAYER SHEAR /GENERALLY 35-40
KT/ WILL BE SUPPORTIVE OF SUPERCELLS CAPABLE OF LARGE HAIL ALONG
WITH SOME TORNADO RISK. CURRENT THINKING IS THAT THE RELATIVELY
GREATEST TORNADO POTENTIAL WILL EXIST BY EARLY EVENING ACROSS PARTS
OF NORTHWEST TX/FAR WESTERN OK NEAR THE DRYLINE...WITH RESIDUAL
OUTFLOW/DIFFERENTIAL HEATING POTENTIALLY AN ADDITIONAL MESOSCALE
FACTOR ASIDE FROM A NOCTURNALLY STRENGTHENING LOW-LEVEL JET. STORMS
SHOULD COALESCE INTO ONE OR MORE EASTWARD-SPREADING MCS/S DURING THE
LATE EVENING/OVERNIGHT HOURS ACROSS OK/KS AS THE LOW-LEVEL JET/WARM
ADVECTION FURTHER INCREASES.
...SOUTHERN MN AND IA/NORTHWEST MO...
A NORTHEASTWARD-MOVING SHORTWAVE TROUGH WILL AT LEAST GLANCE MOST OF
THE REGION...WHILE WIDESPREAD EARLY-DAY CLOUD COVER/SCATTERED
PRECIPITATION WILL LIKELY PRECEDE AN EAST-SOUTHEASTWARD MOVING COLD
FRONT. DEEP-LAYER SHEAR WILL BE MODEST /30-35 KT AT MOST/ AND
UNCERTAINTIES EXIST REGARDING THE RESIDUAL IMPACTS OF EARLY DAY
CLOUDS/PRECIPITATION. HOWEVER...AT LEAST MODEST CLOUD BREAKS/HEATING
AND THE INFLUX OF LOWER 60S F SURFACE DEWPOINTS COULD LEAD TO
MODERATE DESTABILIZATION THROUGH THE AFTERNOON/EARLY EVENING. THIS
MAY LEAD TO AT LEAST AN ISOLATED SEVERE HAIL/WIND RISK AS STORMS
LIKELY REDEVELOP/INTENSIFY NEAR OR EAST OF THE COLD FRONT. PORTIONS
OF THE REGION COULD WARRANT A CATEGORICAL RISK UPGRADE /SLIGHT/ IN
SUBSEQUENT DAY 1 OUTLOOKS.
...NORTHERN/CENTRAL PORTIONS OF NV/UT...
A FEW STRONGER STORMS WILL BE POSSIBLE OVER THE REGION IN
ASSOCIATION WITH THE EXIT REGION OF THE
RETROGRADING/SOUTHWESTWARD-MOVING UPPER LOW OVER THE WESTERN GREAT
BASIN/CENTRAL CA. STEEP LAPSE RATES/MODEST BUOYANCY AND A SUFFICIENT
VERTICAL SHEAR COULD ALLOW FOR LOCALLY STRONGER WINDS AND POSSIBLY
SOME HAIL.
...COASTAL CAROLINAS THURSDAY NIGHT...
WHILE NOT HIGHLY CONFIDENT IN THE DETAILS...A STRENGTHENING
LOW-LEVEL WIND FIELD COULD APPROACH THE COASTAL CAROLINAS AS EARLY
AS THURSDAY NIGHT/EARLY FRIDAY IN ASSOCIATION WITH A POSSIBLE
SUBTROPICAL OR TROPICAL CYCLONE. REFERENCE THE SPECIAL TROPICAL
WEATHER OUTLOOK STATEMENT FROM NHC FOR ADDITIONAL DETAILS. ANY LOW
TORNADO RISK APPEARS TOO SPECULATIVE DURING THE DAY 2 TIME FRAME
WITH CURRENT THINKING BEING THAT ANY MINI-SUPERCELLS WILL BE WELL
OFFSHORE.
..GUYER.. 05/06/2015
Day 3 Outlook
DAY 3 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0224 AM CDT WED MAY 06 2015
VALID 081200Z - 091200Z
...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PORTIONS OF THE CENTRAL
AND SOUTHERN PLAINS...
...THERE IS A MRGL RISK OF SVR TSTMS SURROUNDING THE SLIGHT RISK
AREA FROM THE SOUTHERN/CENTRAL PLAINS TO SOUTHWEST ILLINOIS...
...THERE IS A MRGL RISK OF SVR TSTMS OVER SOUTHEAST NORTH
CAROLINA...
...SUMMARY...
SEVERE THUNDERSTORMS WILL BE POSSIBLE FRIDAY ACROSS PORTIONS OF THE
CENTRAL AND SOUTHERN PLAINS NORTHEAST INTO SOUTHWEST ILLINOIS.
...SYNOPSIS...
AN UPPER LOW OVER SRN CA WILL MOVE EWD TO CENTRAL AZ DURING FRIDAY
AS A BELT OF SWLY FLOW ALOFT PREVAILS FROM THE SRN/CENTRAL PLAINS
INTO THE GREAT LAKES. A FRONTAL BOUNDARY WILL EXTEND FROM THE
MICHIGAN UPPER PENINSULA SWWD TO THE NRN TX PANHANDLE LATE FRIDAY
AFTN WITH A DRYLINE EXTENDING SWD THROUGH THE TX PANHANDLE/W TX. A
SFC LOW SOUTH OF THE NORTH CAROLINA COAST WILL MOVE NWD. CONSULT THE
LATEST INFORMATION FROM THE NATIONAL HURRICANE CENTER.
...SRN/CENTRAL PLAINS...
A CONVECTIVE COMPLEX MAY BE ONGOING FRIDAY MORNING ACROSS PORTIONS
OF KS/OK AIDED BY WAA ASSOCIATED WITH A SWLY LOW-LEVEL JET. RESIDUAL
OUTFLOW/CLOUDS WILL INFLUENCE THE EFFECTIVE FRONTAL POSITION AND
SUBSEQUENT PREFERRED LOCATIONS FOR NEW TSTM DEVELOPMENT.
HEIGHT FALLS/LARGE-SCALE FORCING FOR ASCENT ASSOCIATED WITH THE
EWD-MOVING UPPER LOW WILL REMAIN W OF THE CENTRAL/SRN PLAINS
FRIDAY...HOWEVER LOW-AMPLITUDE IMPULSES WITHIN THE SWLY FLOW WILL
ONCE AGAIN INFLUENCE AFTN/EVENING CONVECTIVE TRENDS. ONE IMPULSE
TRAVERSING THE CENTRAL PLAINS EARLY FRIDAY MAY AID THE CONTINUATION
OF MORNING TSTMS THROUGH THE AFTN ACROSS PORTIONS OF MO/IL.
THE FOCUS FOR MORE CONSEQUENTIAL TSTM DEVELOPMENT FRI AFTN WILL BE
ALONG THE FRONTAL BOUNDARY AND SWD ALONG THE DRYLINE OVER SRN
KS/OK/W TX. STG SFC-BASED BUOYANCY...40-50 KTS OF DEEP-LAYER SHEAR
AND STEEP MID-LEVEL LAPSE RATES WILL INITIALLY FAVOR SUPERCELLS WITH
LARGE HAIL. RELATIVELY LOW LCL HEIGHTS AND NOCTURNALLY INCREASING
LOW-LEVEL FLOW WILL ALSO RESULT IN A TORNADO THREAT DURING THE
EVENING HOURS BEFORE UPSCALE GROWTH INTO A MESOSCALE CONVECTIVE
COMPLEX OCCURS. DAMAGING WINDS AND LARGE HAIL WILL REMAIN POSSIBLE
AS THE MCS MOVES EWD OVERNIGHT.
...SRN NC COAST...
LATEST GUIDANCE PLACES A SFC LOW ALONG THE COAST NEAR THE NC-SC
BORDER DURING THE DAY FRIDAY...WITH STRONG LOW-LEVEL ELY FLOW
RESULTING IN SUBSTANTIALLY-CURVED LOW-LEVEL HODOGRAPHS. THE RISK FOR
A TORNADO WILL EXIST WITH CONVECTIVE CELLS NEAR/ALONG THE COAST.
..BUNTING.. 05/06/2015
Day 4-8 Outlook
DAY 4-8 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0400 AM CDT WED MAY 06 2015
VALID 091200Z - 141200Z
...DISCUSSION...
THE UPPER LEVEL LOW NEAR THE FOUR CORNERS REGION AT 12Z SAT WILL
LIFT NEWD TOWARDS THE UPPER MIDWEST/GREAT LAKES REGION
TUESDAY...INTERACTING WITH A NRN-STREAM UPPER TROUGH DIGGING SEWD
FROM MANITOBA AS IT SHIFTS INTO THE NERN U.S. BY WED. A WEAKER BELT
OF WLY FLOW ALOFT WILL PERSIST FROM TX ACROSS THE GULF COAST.
...SATURDAY/D4...
DESPITE ANOTHER ROUND OF MORNING TSTMS OVER PORTIONS OF THE
CENTRAL/SRN PLAINS EARLY SAT...THE INGREDIENTS APPEAR TO BE COMING
TOGETHER FOR A SUBSTANTIAL SEVERE WEATHER EVENT ACROSS THE
SRN/CENTRAL PLAINS SAT AFTN/EVENING. ALTHOUGH SOME TIMING/LOCATION
DIFFERENCES EXIST AMONGST LATEST GUIDANCE...THERE IS GENERAL
AGREEMENT ON HEIGHT FALLS/DCVA OVERSPREADING A VERY MOIST WARM
SECTOR /SFC DEW POINTS 65 TO NEAR 70/ AHEAD OF A DRYLINE EXTENDING
FROM SWRN KS SWD INTO W TX. 50-60 KTS OF SWLY 500 MB FLOW WILL
ROTATE AROUND THE UPPER LOW AND ACROSS OK/KS AS A SFC LOW TAKES
SHAPE OVER SWRN KS BY EARLY EVENING. SVR TSTMS WILL LIKELY DEVELOP
ALONG THE DRYLINE AND NEAR THE SFC LOW/WARM FRONT DURING THE AFTN IN
AN ENVIRONMENT FAVORABLE FOR SUPERCELLS WITH ALL SEVERE HAZARDS
POSSIBLE. STORMS SHOULD EVENTUALLY EVOLVE INTO CLUSTERS OR LINES
WITH A CONTINUED SVR THREAT OVERNIGHT.
...SUNDAY/D5...
AS THE SFC LOW LIFTS NEWD TO NR THE NEB/IA BORDER...SVR TSTMS APPEAR
POSSIBLE ONCE AGAIN IN ADVANCE OF A COLD FRONT EXTENDING SWD FROM
THE LOW INTO ERN OK/N TX...AND NEAR/SOUTH OF A WARM FRONT EXTENDING
EWD ACROSS CENTRAL/NRN IL. A PLUME OF STEEPER MID-LEVEL LAPSE RATES
MAY BE IN PLACE SUPPORTING MODERATE-STRONG BUOYANCY AS HEIGHT
FALLS/FORCING FOR ASCENT SHIFTS EWD ACROSS THE AREA. A MIX OF STORM
MODES INCLUDING SUPERCELLS AND LINES/CLUSTERS APPEARS PROBABLE.
...MONDAY/D5 AND BEYOND...
UNCERTAINTY INCREASES DURING THIS TIME AS TIMING/LOCATION
DIFFERENCES IN SFC AND UPPER LEVEL FEATURES RENDERS INSUFFICIENT
CONFIDENCE TO OUTLINE RISK AREAS...THOUGH SOME SVR POTENTIAL MAY
EXIST FROM PORTIONS OF LOWER MI SWD ACROSS THE OH/TN VALLEY
REGION...AND POTENTIALLY AS FAR SOUTH AS LWR MS VALLEY. WILL DEFER
TO LATER OUTLOOKS FOR POSSIBLE AREAL DELINEATION OF SVR RISK AREAS.
..BUNTING.. 05/06/2015
you think SPC will go high risk on Saturday??
