It is definitely a thought on the minds of many on the heels of what has been called one of the biggest severe weather outbreaks in recent memory. We are barely one day removed from this outbreak and the weather forecasters at the Storm Prediction Center is forecasting just that. A slight risk map has already been issued for Tuesday. Here is that map below.
Keep in mind in the verbage that you are going to read below from the SPC, some areas could be upgraded to a moderate risk in the Convective Outlook for Monday. Here is what they said about the severe weather risk for Tuesday. Subsequent blog posts will note any changes to this.
DAY 3 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0230 AM CDT SUN APR 17 2011
VALID 191200Z – 201200Z
…THERE IS A SLGT RISK OF SVR TSTMS ACROSS MUCH OF THE MIDWEST/OH
RIVER VALLEY TO EASTERN OK/ARKLATEX…
…MIDWEST AND OH/MIDDLE MS RIVER VALLEYS TO THE SOUTHERN
A VERY ACTIVE SEVERE WEATHER DAY IS EXPECTED ACROSS THE REGION ON
TUESDAY…INCLUDING THE POSSIBILITY OF TORNADOES/LARGE HAIL AND
DAMAGING WINDS ESPECIALLY TUESDAY AFTERNOON/NIGHT.
INITIALLY…ELEVATED EARLY DAY TSTMS /SOME CAPABLE OF SEVERE HAIL/
WILL BE ONGOING ACROSS THE MIDWEST/OH RIVER VALLEY ON THE EDGE OF A
NORTHEASTWARD BUILDING ELEVATED MIXED LAYER. OTHERWISE…BENEATH THE
BUILDING CAP…LOW LEVEL MOISTURE WILL AGGRESSIVELY ADVECT
NORTHEASTWARD AS STRONG SOUTHWESTERLY LOW LEVEL WINDS ARE MAINTAINED
THROUGH THE DAY. ACCORDINGLY…LOWER TO MIDDLE 60S F SURFACE
DEWPOINTS WILL BECOME INCREASINGLY ESTABLISHED TO THE EAST OF A
LOWER MO VALLEY SURFACE LOW AND ALONG/SOUTH OF A NORTHWARD MOVING
WARM FRONT ACROSS THE OH RIVER VALLEY/MIDWEST. BENEATH THE STRONG
EML/PLUME OF STEEP MID LEVEL LAPSE RATES…MODERATELY TO STRONG
INSTABILITY WILL LIKELY EXIST ACROSS THE PRE-COLD FRONT WARM SECTOR
BY AFTERNOON…WITH UPWARDS OF 2000-4000 J/KG OF MLCAPE POSSIBLE.
AIDED BY A NORTHEASTWARD ADVANCING SHORTWAVE TROUGH/ASSOCIATED
HEIGHT FALLS…TSTMS SHOULD ERUPT BY MID/LATE AFTERNOON INTO EARLY
EVENING AHEAD OF A DEEPENING LOWER MO VALLEY/MIDDLE MS VALLEY
SURFACE LOW AND NORTHEAST-SOUTHWEST ORIENTED COLD FRONT. SUCH
VIGOROUS DEEP CONVECTIVE DEVELOPMENT CURRENTLY APPEARS MOST PROBABLE
TO INITIALLY OCCUR ACROSS EASTERN/SOUTHERN MO INTO WESTERN IL…AND
A BIT LATER ACROSS EASTERN OK/NORTHWEST AR IN VICINITY OF THE
AMPLE LOW LEVEL MOISTURE/VERY STRONG LAPSE RATES AND DEEP LAYER
SHEAR OF 35-45 KT COINCIDENT WITH THE COLD FRONT/NEARBY WARM SECTOR
WILL BE FURTHER ACCENTUATED BY LONG/CURVING LOW LEVEL HODOGRAPHS
AIDED BY 40-55 KT WINDS WITHIN THE LOWEST 1-2 KM. THUS…INITIAL
MODE SUPERCELLS CAPABLE OF VERY LARGE HAIL AND TORNADOES CAN BE
EXPECTED…WITH MORE OF A DAMAGING WIND AND ISOLATED TORNADO THREAT
EVOLVING DURING THE EVENING AS SUBSEQUENT QUASI-LINEAR BOW
PORTIONS OF THE REGION WILL LIKELY NEED TO BE UPGRADED TO A MODERATE
RISK IN SUBSEQUENT DAY 2 OUTLOOKS.