Jun 4, 2008 1630 UTC Day 1 Convective Outlook
Updated: Wed Jun 4 17:18:21 UTC 2008
Probabilistic to Categorical Outlook Conversion Table (Effective Feb 14, 2006).
Public Severe Weather Outlook

The SPC is forecasting ...severe thunderstorms expected over parts of the central plains and mid atlantic region this afternoon and tonight....   Please read the latest public statement about this event.

Categorical Graphic
20080604 1630 UTC Day 1 Outlook Graphic
Probabilistic Tornado Graphic
20080604 1630 UTC Day 1 Tornado Probabilities Graphic
Torndao Legend Image
Probabilistic Damaging Wind Graphic
20080604 1630 UTC Day 1 Damaging Wind Probabilities Graphic
Wind Legend Image
Probabilistic Large Hail Graphic
20080604 1630 UTC Day 1 Large Hail Probabilities Graphic
Hail Legend Image
   SPC AC 041630
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1130 AM CDT WED JUN 04 2008
   
   VALID 041630Z - 051200Z
   
   ...THERE IS A MDT RISK OF SVR TSTMS FROM NRN KS INTO SRN NEB...
   
   ...THERE IS A MDT RISK OF SVR TSTMS FROM ERN WV THROUGH MUCH OF
   VA...MD AND DE...
   
   ...THERE IS A SLGT RISK OF SVR TSTMS FROM PARTS OF THE CNTRL PLAINS
   THROUGH THE MID MS VALLEY...OH VALLEY AND MID ATLANTIC REGIONS...
   
   ...SYNOPSIS...
   THE ACTIVE SEVERE WEATHER PATTERN OF RECENT DAYS WILL CONTINUE THIS
   PERIOD AS WA/ORE UPR LOW AMPLIFIES SE ACROSS THE GREAT BASIN AND
   DOWNSTREAM RIDGE BUILDS FROM THE NRN GULF ACROSS THE SERN STATES. 
   EXISTING BELT OF FAST WSW FLOW FROM THE CNTRL/SRN PLNS TO THE OH VLY
   WILL REMAIN STRONG BUT BACK WITH TIME...WHILE EQUALLY STRONG WLY
   WINDS PERSIST OVER THE EAST.
   
   AT THE SFC...FRONT NOW EXTENDING WWD FROM THE MID ATLANTIC CST TO
   THE CNTRL PLNS SHOULD REMAIN NEARLY STATIONARY MOST OF TODAY.  LATER
   TODAY AND TONIGHT...EXPECT WRN PART OF THE FRONT TO BEGIN MOVING N
   ACROSS KS/MO AND IL AS LOW- TO MID-LVL FLOW BACKS...AND LEE LOW
   DEEPENS IN ERN CO/WRN KS.
   
   ...NWRN OK/KS INTO MO/NEB/IA...
   VERY MOIST AIR WITH SFC DEWPOINTS IN THE UPR 60S WILL PERSIST ALONG
   AND S OF THE STNRY/WARM FRONT OVER THE PLNS/LWR MO VLY...AND E OF
   THE DRY LINE EXTENDING SSW FROM WRN KS SFC LOW.  COMBINED WITH STEEP
   MID-LVL LAPSE RATES...DIURNAL DESTABILIZATION WILL BOOST SBCAPE TO
   2500-3000 J/KG FROM NRN OK NE INTO MUCH OF CNTRL/ERN KS ...SRN
   NEB...NW MO AND SW IA.  NEVERTHELESS...EML CAP SHOULD KEEP REGION
   FREE OF DEEP CONVECTIVE DEVELOPMENT UNTIL LATE AFTN.
   
   COMBINATION OF STRONG HEATING AND FRONTAL UPLIFT SHOULD SUPPORT
   SFC-BASED STORM DEVELOPMENT BY LATE IN THE DAY ALONG FRONT IN NRN KS
   AND SRN NEB...SPREADING INTO NWRN MO AND WRN IA DURING THE EVENING. 
   FARTHER SW...MORE ISOLD ACTIVITY MAY FORM IN NW OK/S CNTRL KS...NEAR
   INTERSECTION OF DRY LINE WITH SHALLOW FRONTAL SEGMENT LEFT OVER
   REGION FROM YESTERDAY.
   
   GIVEN DEGREE OF INSTABILITY AND CONTINUING PRESENCE OF SEASONABLY
   STRONG SWLY MID-LVL FLOW ATOP STRONG SSWLY LLJ...SUPERCELLS WILL BE
   LIKELY.  THESE COULD YIELD VERY LARGE HAIL...HIGH WIND AND
   TORNADOES.  THE GREATEST TORNADO THREAT MAY DEVELOP THIS EVENING
   INVOF THE KS SFC LOW...ENEWD ALONG THE WARM FRONT INTO CNTRL/NRN KS
   AND INTO SRN NEB AS LLJ STRENGTHENS TOWARD SUNSET.
   
   STORMS SHOULD INCREASE IN COVERAGE AND SPREAD NEWD THROUGH THE MID
   MO VLY TONIGHT ALONG NOSE OF STRENGTHENING/BACKING 60-65 KT SSWLY
   LLJ.  MANY OF THESE STORMS WILL LIKELY BE SLIGHTLY ELEVATED...BUT
   WILL CONTINUE TO POSE A THREAT FOR LARGE HAIL AND POSSIBLY LOCALLY
   DMGG WIND/ISOLD TORNADOES.
   
   ...CNTRL HI PLNS...
   DIURNAL STORMS ARE POSSIBLE IN UPSLOPE FLOW REGIME NW OF WRN KS/ERN
   CO SFC LOW IN NE CO/SW NEB AND PERHAPS NW KS/SE WY.  MODERATELY
   STRONG INSTABILITY/VERTICAL SHEAR AND LACK OF LINEAR FORCING WILL
   FOSTER SUPERCELLULAR STORMS CAPABLE OF LARGE HAIL...DMGG WIND AND
   POSSIBLE TORNADOES.  THIS ACTIVITY MAY CONSOLIDATE INTO AN MCS THAT
   CONTINUES E OR ENE INTO NW KS AND CNTRL NEB OVERNIGHT.
   
   
   ...MID ATLANTIC REGION...
   BOUNDARY LAYER MOISTURE IS WELL-ESTABLISHED OVER THE MID ATLANTIC
   REGION...S OF STNRY FRONT EXTENDING EWD FROM CNTRL PA TO NEAR NYC.
   FARTHER S...A WEAK OUTFLOW BOUNDARY FROM OVERNIGHT STORMS ATTM
   EXTENDS FROM N OF CRW ESE TO N OF RIC.  SATELLITE DATA SUGGEST THAT
   MODERATE TO LOCALLY STRONG HEATING WILL OCCUR OVER WV/VA/MD AND DE. 
   GIVEN MOISTURE AVAILABILITY AND FAIRLY STEEP MID-LVL LAPSE
   RATES...THIS SHOULD YIELD SBCAPE TO AOA 2000 J/KG...WITH SLIGHTLY
   GREATER VALUES POSSIBLE NEAR THE I-95 CORRIDOR.
   
   UPSTREAM...MCV NOW OVER IND EXPECTED TO CONTINUE E AT ABOUT 40 KTS. 
   COMBINATION OF MCV-INDUCED ASCENT...AND UPLIFT ALONG FRONT...OUTFLOW
   BOUNDARY AND THE HIGHER TERRAIN...SHOULD RESULT IN FAIRLY WIDESPREAD
   STORM COVERAGE AS HEATING DESTABILIZES REGION TODAY.
   
   WIND PROFILES WILL FEATURE 40+ KT DEEP...UNIDIRECTIONAL WLY
   FLOW...WITH MINIMAL CLOUD-LAYER SHEAR.  THIS SUGGESTS THAT WHILE 
   SEMI-DISCRETE STORMS/POSSIBLE SUPERCELLS MAY OCCUR...ESPECIALLY
   ALONG THE AFOREMENTIONED BOUNDARIES...THE MAIN OVERALL
   ORGANIZATIONAL MODE OF THE CONVECTION SHOULD BE FORWARD-PROPAGATING
   LINES.  EMBEDDED STORMS COULD YIELD DMGG WIND...SVR HAIL AND PERHAPS
   A COUPLE TORNADOES THROUGH EARLY EVENING...BEFORE MOST OF THE
   ACTIVITY MOVES OFFSHORE/WEAKENS.
   
   IN THE WAKE OF THE ABOVE CONVECTION...ADDITIONAL WAVES OF WEAKER
   STORMS MAY PERSIST OVER NRN PARTS OF THE MID ATLANTIC STATES THROUGH
   EARLY THURSDAY.
   
   ..DIAL/GRAMS/CORFIDI.. 06/04/2008
   
   CLICK TO GET WUUS01 PTSDY1 PRODUCT

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 2000Z