May 30, 2014 2000 UTC Day 1 Convective Outlook
Updated: Fri May 30 19:59:37 UTC 2014 (20140530 2000Z Day 1 shapefile | 20140530 2000Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20140530 2000 UTC Day 1 Outlook Graphic
Probabilistic Tornado Graphic
20140530 2000 UTC Day 1 Tornado Probabilities Graphic
Probability of a tornado within 25 miles of a point.
Hatched Area: 10% or greater probability of EF2 - EF5 tornadoes within 25 miles of a point.
Probabilistic Damaging Wind Graphic
20140530 2000 UTC Day 1 Damaging Wind Probabilities Graphic
Probability of damaging thunderstorm winds or wind gusts of 50 knots or higher within 25 miles of a point.
Hatched Area: 10% of greater probability of wind gusts 65 knots or greater within 25 miles of a point.
Probabilistic Large Hail Graphic
20140530 2000 UTC Day 1 Large Hail Probabilities Graphic
Probability of hail 1" or larger within 25 miles of a point.
Hatched Area: 10% or greater probability of hail 2" or larger within 25 miles of a point.
Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
SLIGHT 35,142 169,465 Scottsbluff, NE...Pierre, SD...Sterling, CO...Chadron, NE...Rosebud, SD...
   SPC AC 301956

   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0256 PM CDT FRI MAY 30 2014

   VALID 302000Z - 311200Z

   ...THERE IS A SLGT RISK OF SVR TSTMS FROM NERN CO INTO WRN NEB AND
   CNTRL SD...

   ...SUMMARY...
   A FEW SEVERE THUNDERSTORMS WILL BE POSSIBLE FROM NORTHEASTERN
   COLORADO INTO NORTH DAKOTA...WITH MORE ISOLATED ACTIVITY ACROSS THE
   CAROLINAS AND SOUTHWEST VIRGINIA...FLORIDA...AND THE CENTRAL GULF
   COAST.

   ...NERN CO INTO WRN NEB...SD AND ND...
   ISOLATED SEVERE STORMS CAPABLE OF LARGE HAIL CONTINUE TO EVOLVE
   ACROSS WRN NEB THIS AFTERNOON...WITH OTHER ACTIVITY INTO NERN CO.
   SATELLITE IMAGERY SHOWS A WEAK UPPER DISTURBANCE MOVING NEWD ACROSS
   SRN CO...AND THIS MAY SUPPORT FURTHER DEVELOPMENT THIS AFTERNOON.
   WEAKLY VEERING WIND PROFILES WITH HEIGHT...AMPLE MOISTURE AND
   SUFFICIENT LAPSE RATES WILL FAVOR SEVERE HAIL...BUT WEAK SHEAR ALSO
   SUGGESTS MULTICELLULAR CONVECTION WILL BE POSSIBLE WHICH WOULD FAVOR
   OUTFLOW WINDS.

   FARTHER N...HEATING PERSISTS FROM SD INTO ERN ND AND NWRN MN NEAR
   THE INVERTED SURFACE TROUGH. ISOLATED SEVERE STORMS WITH MAINLY A
   HAIL THREAT CONTINUE TO BE POSSIBLE IN THESE AREAS DRIVEN MAINLY BY
   INSTABILITY.

   ...ARKLAMISS INTO AL...
   AREAS OF VIGOROUS CONVECTION CONTINUE TO PROPAGATE IN A GENERALLY
   NWD DIRECTION. GIVEN FAVORABLE TIME OF DAY...AMPLE MOISTURE AND
   AREAS OF HEATING...A WET MICROBURST CANNOT BE RULED OUT.

   ...ERN NY INTO NEW ENGLAND...
   SCATTERED LOW-TOPPED THUNDERSTORMS CONTINUE TO EVOLVE SWD IN ADVANCE
   OF A WEAK UPPER LOW ACROSS ERN NY INTO NEW ENGLAND WHERE HEATING HAS
   LED TO WEAK DESTABILIZATION. WITH LOW DEWPOINTS AND WEAK SHEAR...THE
   ENVIRONMENT WILL CONTINUE TO FAVOR SMALL NON-SEVERE HAIL.

   ..JEWELL.. 05/30/2014

   .PREV DISCUSSION... /ISSUED 1133 AM CDT FRI MAY 30 2014/

   ...CENTRAL HIGH PLAINS INTO THE NRN PLAINS...
   SOUTHWEST FLOW ALOFT IS FORECAST TO PERSIST ACROSS THE NRN ROCKIES
   INTO THE NRN PLAINS AS A HIGH AMPLITUDE BLOCKING PATTERN CONTINUES. 
   WATER VAPOR IMAGERY INDICATES AN EMBEDDDED SHORT WAVE TROUGH LIFTING
   NEWD ACROSS NWRN CO AND CENTRAL WY TOWARD THE NRN PLAINS ALONG THE
   WRN EDGE OF A DEEP MOISTURE PLUME EXTENDING FROM CO INTO ND.  12Z
   SOUNDINGS AND SATELLITE DATA EXHIBIT PW VALUES AROUND 1 IN WITHIN
   THIS PLUME WITH MODEL GUIDANCE FORECASTING A SLOW INCREASE IN TOTAL
   MOISTURE INTO TONIGHT.  ASSOCIATED WIDESPREAD CLOUD COVER AND
   ISOLATED CONVECTION ARE EVIDENT AT THIS TIME...ALTHOUGH VISIBLE
   IMAGERY SUGGESTS STRONGER DIABATIC HEATING AND DESTABILIZATION WILL
   OCCUR ALONG THE ERN EDGE OF THE CLOUD BAND FROM NERN CO INTO CENTRAL
   SD THIS AFTERNOON.  GIVEN SURFACE DEW POINTS IN THE MID 50S TO LOWER
   60S...THE HEATING WILL CONTRIBUTE TO MLCAPE OF 1000-1500 J/KG LATER
   THIS AFTERNOON AND EVENING.

   MODEL GUIDANCE INDICATES ADDITIONAL STORMS WILL DEVELOP THIS
   AFTERNOON WITHIN A WEAKLY CAPPED ENVIRONMENT FROM NERN CO/SERN WY
   NEWD INTO THE DAKOTAS NEAR A SLOW MOVING SW/NE ORIENTED SURFACE
   FRONT.  STRONGER SWLY WINDS ALOFT ARE LOCATED GENERALLY ALONG/WEST
   OF THE FRONT WHERE DEEP LAYER SHEAR OF 30-40 KT IS FORECAST.  THIS
   WILL PROMOTE POTENTIAL FOR A FEW ORGANIZED STORMS/WEAK SUPERCELLS TO
   DEVELOP NEAR AND IMMEDIATELY WEST OF THE SURFACE FRONT THAT WILL BE
   CAPABLE OF STRONG WIND GUSTS AND MARGINALLY SEVERE HAIL.  ACTIVITY
   WILL CONTINUE MOVING NEWD INTO TONIGHT IN RESPONSE TO INCREASING LOW
   LEVEL CONVERGENCE/WARM ADVECTION IN ASSOCIATION WITH A STRENGTHENING
   NOCTURNAL LOW LEVEL JET OVER THE NRN PLAINS. 

   ...WRN WY THIS AFTERNOON/EVENING...

   POST-FRONTAL UPSLOPE FLOW WILL ENCOURAGE ISOLATED TSTM DEVELOPMENT
   BY AFTERNOON WITHIN A STEEP LAPSE RATE AND AT LEAST MARGINALLY
   UNSTABLE THERMODYNAMIC ENVIRONMENT. THIS INSTABILITY WILL ALIGN WITH
   MODESTLY STRONG MID TO UPPER-TROPOSPHERIC FLOW WHICH MAY BE
   CONDUCIVE FOR A FEW SEVERE STORMS CAPABLE OF HAIL AND LOCALLY STRONG
   WIND GUSTS.  

   ...FL THIS AFTERNOON...

   SCATTERED AFTERNOON TSTM DEVELOPMENT IS ANTICIPATED ALONG THE
   DEVELOPING SEA BREEZE FRONTS.  WINDS ALOFT REMAIN QUITE WEAK /AOB 10
   KT THROUGH 500 MB/ SUGGESTING INITIAL STORMS WILL EXHIBIT PULSE
   CHARACTERISTICS.  HOWEVER...SOME CONVECTION-ALLOWING MODEL GUIDANCE
   SHOW SOME STORMS POTENTIALLY GROWING UPSCALE INTO
   WWD-MOVING CLUSTERS. THE COMBINATION OF A VERY MOIST AIR MASS AND
   ATTENDANT PRECIPITATION-LOADING EFFECTS MAY ENHANCE MICROBURST
   POTENTIAL...WHILE 500 MB TEMPERATURES OF AROUND -10 C WILL LOCALLY
   STRONGER UPDRAFTS AND A THREAT FOR MARGINAL HAIL.  

   ...CAROLINAS AND SOUTHWEST VA THIS AFTERNOON/EVENING...

   VISIBLE IMAGERY SHOWS CU AND ISOLATED DEEP CONVECTION BEGINNING TO
   DEVELOP OVER THE CENTRAL APPALACHIANS AT THIS TIME AS CONTINUED
   HEATING OF A MOIST AIR MASS SURFACE DEW POINTS IN THE 60S OCCURS
   OVER THE HIGHER TERRAIN.  WIDELY SCATTERED TO SCATTERED TSTMS ARE
   EXPECTED TO CONTINUE DEVELOPING INVOF THE STALLED SURFACE FRONT AND
   SPREAD SEWD ALONG THE SRN EDGE OF WEAK NWLY FLOW ALOFT. ALTHOUGH
   WEAK VERTICAL SHEAR WILL LIKELY LIMIT STORM
   ORGANIZATION/LONGEVITY...ISOLATED OCCURRENCES OF
   HAIL/LOCALLY DAMAGING WINDS ARE POSSIBLE.

   ...CNTRL GULF COAST...

   THE 12Z LIX SOUNDING SAMPLED A MOIST...MODERATELY UNSTABLE AIR MASS 
   WITH A PW OF 1.8 INCHES AND MLCAPE OF AROUND 1600 J/KG. CONTINUED
   HEATING AHEAD OF A CONVECTIVE BAND FROM SRN MS INTO SERN LA IS
   EXPECTED TO INCREASE CAPE TO ABOVE 2000 J/KG THIS AFTERNOON. 
   RELATIVELY WEAK BUT VEERING LOW LEVEL WINDS COUPLED WITH LOW LCL
   HEIGHTS MAY SUPPORT TRANSIENT MESOCYCLONES IN THE STORMS OVER SERN
   LA/SERN MS/SWRN AL COAST...WITH A CONTINUED THREAT FOR A BRIEF
   TORNADO OR TWO THIS AFTERNOON.

   ...ERN NY INTO NEW ENGLAND...
   A STRONG MID/UPPER LEVEL JET STREAK IS PROGRESSING SSEWD ACROSS
   CENTRAL NY ON THE WEST SIDE OF THE COLD UPPER TROUGH MOVING SLOWLY
   EWD ACROSS NEW ENGLAND.  CONVECTION HAS BEEN DEVELOPING FROM THE ST
   LAWRENCE VALLEY INTO NERN NY AND NEW ENGLAND WITHIN THE LEFT EXIT
   REGION OF THE JET STREAK.  ALTHOUGH MOISTURE IS MARGINAL WITH
   SURFACE DEW POINTS ONLY NEAR 50...COOLING ALOFT WILL RESULT IN
   SBCAPE REACHING NEAR 500 J/KG THIS AFTERNOON WITH AN INCREASE IN
   LOW-TOPPED CONVECTION/THUNDERSTORMS EXPECTED.  STRONGER CELLS MAY BE
   CAPABLE OF PRODUCING MAINLY SMALL HAIL AND STRONG WIND GUSTS THROUGH
   THE AFTERNOON HOURS.

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