Apr 8, 2015 2000 UTC Day 1 Convective Outlook

DAY 1 CONVECTIVE OUTLOOK  

   NWS STORM PREDICTION CENTER NORMAN OK
   0232 PM CDT WED APR 08 2015

   VALID 082000Z - 091200Z

   ...THERE IS A MDT RISK OF SVR TSTMS LATE THIS AFTERNOON AND EVENING
   FROM PARTS OF NORTHERN OKLAHOMA AND SOUTHEAST KANSAS INTO WESTERN
   AND SOUTHERN MISSOURI...

   ...THERE IS AN ENH RISK OF SVR TSTMS SURROUNDING THE MDT RISK
   AREA...FROM NORTH CENTRAL OKLAHOMA EAST NORTHEASTWARD INTO SOUTHERN
   INDIANA...

   ...THERE IS A SLGT RISK OF SVR TSTMS ACROSS SURROUNDING AREAS OF THE
   SOUTHERN AND CENTRAL PLAINS THROUGH THE OHIO VALLEY...

   ...THERE IS A MRGL RISK OF SVR TSTMS AS FAR EAST AS THE CENTRAL
   APPALACHIANS REGION...AND AS FAR SOUTH AS THE EDWARDS PLATEAU AND
   ADJACENT RIO GRANDE VALLEY AREA...

   ...SUMMARY...
   VERY LARGE HAIL...DAMAGING WIND AND TORNADOES ARE EXPECTED OVER
   PARTS OF THE CENTRAL PLAINS AND LOWER MISSOURI VALLEY LATE THIS
   AFTERNOON AND EVENING.  OTHER STRONG TO SEVERE STORMS MAY DEVELOP
   FROM PARTS OF TEXAS NORTHEASTWARD INTO THE OHIO VALLEY AND CENTRAL
   APPALACHIANS.

   ...20Z OUTLOOK UPDATE...
   SEVERE WIND PROBABILITIES HAVE BEEN INCREASED ACROSS THE MODERATE
   RISK AREA.  OTHERWISE...THERE IS LITTLE EVIDENT IN THE LATEST MODEL
   OUTPUT OR OBSERVATIONAL DATA TO PROVIDE JUSTIFICATION FOR
   APPRECIABLE CHANGES TO THE ONGOING OUTLOOK.  AS AN INITIAL MID/UPPER
   LEVEL SPEED MAXIMUM NOSES NORTHEASTWARD THROUGH THE CENTRAL
   PLAINS...THUNDERSTORM ACTIVITY IS IN THE PROCESS OF INTENSIFYING
   NEAR/OR EAST NORTHEAST OF THE DRYLINE/COLD FRONT INTERSECTION ACROSS
   THE CENTRAL PLAINS.  A NARROW CORRIDOR OF STRONGER PRE-FRONTAL
   SURFACE HEATING AND DESTABILIZATION... EXTENDING EAST NORTHEAST OF
   THIS ACTIVITY INTO THE MISSOURI OZARKS...MAY PROVIDE THE FOCUS FOR
   FURTHER INTENSIFICATION AND INCREASING SEVERE WEATHER POTENTIAL
   THROUGH THE REMAINDER OF THE AFTERNOON.  OTHERWISE...THE
   QUASI-STATIONARY SURFACE FRONTAL ZONE...ROUGHLY NEAR THE
   KANSAS/OKLAHOMA BORDER AREA EASTWARD THROUGH THE MIDDLE MISSISSIPPI
   VALLEY...IS STILL EXPECTED TO BECOME THE FOCUS FOR THE PRIMARY STORM
   DEVELOPMENT THROUGH THE REMAINDER OF THE PERIOD.  IT IS POSSIBLE
   THAT THE MOST SIGNIFICANT INCREASE IN COVERAGE/INTENSITY ALONG THE
   PLAINS PORTIONS OF THIS BOUNDARY MAY NOT OCCUR UNTIL THE 00-02Z TIME
   FRAME...WHEN THE SOUTHERLY 850 MB JET FINALLY BEGINS TO STRENGTHEN.

   ..KERR.. 04/08/2015

   .PREV DISCUSSION... /ISSUED 1155 AM CDT WED APR 08 2015/

   ...SYNOPTIC SETUP...
   PROGRESSIVE SPLIT FLOW WILL PREVAIL OVER THE CNTRL AND ERN STATES
   THROUGH THU...DOWNSTREAM FROM DEAMPLIFYING LARGER-SCALE TROUGH NOW
   OVER THE GRT BASIN. THE GRT BASIN TROUGH SHOULD REACH THE CNTRL HIGH
   PLNS BY 12Z THU AS A LWR-AMPLITUDE SRN BRANCH DISTURBANCE NOW
   CROSSING NRN BAJA ACCELERATES ENE TO FAR W TX THIS EVE AND INTO ERN
   OK EARLY THU.

   AT THE SFC...APPROACH OF UPR IMPULSES WILL BE ACCOMPANIED BY
   DEEPENING/CONSOLIDATION OF LEE LOW OVER SE CO LATER TODAY. THE LOW
   SHOULD TRACK ENE ALONG FRONT NOW STALLING OVER NRN OK/SRN KS INTO NW
   MO BY THE END OF THE PERIOD. WAVY STNRY/WARM FRONT EXTENDING E FROM
   THE LOW...AUGMENTED IN PLACES BY MCS OUTFLOW...WILL BE A FOCUS FOR
   PERIODIC STRONG TO SVR TSTMS THROUGH EARLY THU...WITH OTHER STORMS
   LIKELY TO FORM LATER TODAY INTO TNGT NEAR THE SFC LOW...AND MORE
   ISOLD ACTIVITY SSW ALONG TRAILING DRY LINE.

   ...MID OH VLY TO CNTRL APPALACHIANS TODAY INTO TNGT...
   AREA VWP DATA AND DIURNAL HEATING SUGGEST THAT SW OH SQLN WILL
   CONTINUE MAINLY ESE...WITH A CONTINUING RISK FOR SVR WIND/MARGINALLY
   SVR HAIL /REF WW 229/. SYSTEM COULD CONTINUE AND/OR PARTIALLY
   RE-DEVELOP E OF THE WV MTNS INTO WRN/SRN VA...WITH A CONTINUING RISK
   FOR LOCALLY DMGG WIND W AND S OF STALLING BACK-DOOR FRONT.

   ...MID-MS TO MID OH VLY TODAY/TNGT...
   PERSISTENT WAA/MOISTURE TRANSPORT ATOP STALLED FRONT/CONVECTIVE
   OUTFLOW IS LIKELY TO YIELD EPISODIC STORMS DEVELOPMENT THROUGH THU
   MORNING FROM PARTS OF MO EWD INTO IND/KY. WITH SATELLITE AND RAOB
   DATA INDICATING ONLY WEAK DISTURBANCES IN SW FLOW
   ALOFT...DEVELOPMENT WILL MOST STRONGLY BE MODULATED BY /1/ DIURNAL
   HEATING TODAY...AND /2/ NOCTURNAL ENHANCEMENT OF LLJ TNGT. AMPLE
   BUOYANCY /BOOSTED BY EML/ AND DEEP WSWLY SHEAR WILL BE PRESENT FOR
   SUPERCELLS...WITH THE STORMS LIKELY EVOLVING INTO COMPLEX
   LINES/CLUSTERS POSING A RISK FOR SVR HAIL...DMGG WIND...AND
   ESPECIALLY DURING EARLY STAGES OF STORM DEVELOPMENT...TORNADOES.

   ...SRN/CNTRL PLNS INTO OZARKS LATE THIS AFTN THROUGH EARLY THU...
   CONDITIONS MAY BECOME INCREASINGLY FAVORABLE FOR A FEW
   LONGER-LIVED...DISCRETE OR SEMI-DISCRETE SUPERCELLS THIS EVE THROUGH
   LATE TNGT NEAR AND ENE OF SFC WAVE TRACKING ENE ACROSS S CNTRL KS
   AND ADJACENT NRN OK/W CNTRL MO. GIVEN THAT THE LOW-LVL FLOW LIKELY
   WILL APPRECIABLY/STRENGTHEN GIVEN BOTH TIME OF DAY AND THE
   FAVORABLY-TIMED APPROACH OF BAJA JET MAX...THE CORRESPONDING
   INCREASE IN LOW-LVL HODOGRAPH LENGTH AND CURVATURE COULD YIELD AN
   ENHANCED RISK FOR A STRONG TORNADO OR TWO. MORE ISOLD TSTMS WITH A
   RISK FOR VERY LARGE HAIL AND A COUPLE TORNADOES ARE EXPECTED SSW
   ALONG DRY LINE INTO W CNTRL TX.

   ...LWR MO VLY EWD TO LWR GRT LKS TODAY THROUGH EARLY THU...
   SOME RISK ALSO WILL EXIST THROUGH THE PERIOD FOR SCTD SMALL
   CLUSTERS/BANDS OF ELEVATED STORMS WITH A POTENTIAL FOR SVR HAIL
   FARTHER N OF SFC WAVE AND STNRY/WARM FRONT...WITH ACTIVITY ROOTED
   INTO THE 850-700 MB LAYER TAPPING THE PERSISTENT EML ASSOCIATED WITH
   THE FAST WSWLY MID-LVL FLOW.