SPC DAY-1 CONVECTIVE OUTLOOK

15 Apr 1998 - 15:13:45 UTC 

ZCZC MKCSWODY1 000
ACUS1 KMKC 151513
MKC AC 151513

CONVECTIVE OUTLOOK...REF AFOS NMCGPH94O.

VALID 151500Z - 161200Z

THERE IS A HIGH RISK OF SVR TSTMS OVER PARTS OF MO/KY/TN/AR AND IL. 
THIS AREA LIES TO THE RIGHT OF A LINE FROM 30 W STL 40 SE MVN 20
ENE OWB 45 E BWG 20 ESE BNA 30 SW MKL 50 ENE LIT 15 S SGF 20 WNW
TBN 30 W STL.

THERE IS A MDT RISK OF SVR TSTMS OVER PARTS OF MO/IL/IND/KY/TN/AR/
IA AND OH TO THE RIGHT OF A LINE FROM 25 S MEM HOT UMN SZL 20 E 3OI
MLI 35 S SBN 30 WSW DAY 50 ESE LUK 20 SSE LOZ 40 SE BNA 25 S MEM.

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM PRX
MLC 40 NW FYV 25 NW SZL 35 W DSM JVL GRR DTW CLE 25 W HLG BKW TRI
35 NW AHN 25 W ATL 20 W GAD TUP ELD PRX.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 15 WSW GLS TYR PRX
30 W MLC 40 E BVO MKC 10 NNW SUX MSP RHI 15 NNW APN ...CONT... ART
15 E ISP ...CONT... 15 NE JAX 30 SE TLH.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM P28 CSM LVS
25 WSW ABQ 45 NE E74 DAG SAC MHS LMT RDM YKM GEG HLN CPR P28.

...SEVERE THUNDERSTORM FORECAST DISCUSSION...
BROAD UPPER TROF WILL CONTINUE ACROSS THE WRN U.S. ASSOCIATED
POLAR JET WILL CONTINUE TO EXTEND FROM THE SRN ROCKIES ACROSS THE
SRN PLAINS INTO THE MID MS VALLEY. EMBEDDED SPEED MAX NOW OVER IA
SHOULD MOVE NE TOWARD THE WRN GREAT LAKES BY THURSDAY MORNING...
WHILE IMPULSE NOW OVER AZ SWEEPS ENE INTO THE SRN PLAINS. 

AT THE SURFACE...MAIN SYNOPTIC LOW ASSOCIATED WITH IA SHORTWAVE
SHOULD CONTINUE ENE TO NEAR LAKE MI. FARTHER S...EXPECT AN
ADDITIONAL SURFACE WAVE TO TRACK ENEWD ACROSS SRN MO INTO THE LWR
OH VALLEY BY THE END OF THE PERIOD...AT INTERSECTION OF EXISTING
E/W OUTFLOW BOUNDARY AND EWD MOVING COLD FRONT OVER ERN OK/SE KS. 

...SRN MO/NRN AR INTO THE LWR OH VALLEY...
SURFACE HEATING AND CONVERGENCE ALONG NEARLY STATIONARY E/W OUTFLOW
BOUNDARY LEFT BY OVERNIGHT CONVECTION LIKELY TO RESULT IN SEVERE
THUNDERSTORM DEVELOPMENT OVER SRN MO/NRN AR AND WRN PORTIONS OF
KY/TN LATER TODAY. SUSTAINED 30 KT SWLY LOW LEVEL FLOW WILL
MAINTAIN AXIS OF LOW 60S DEWPOINTS S OF BOUNDARY. COUPLED WITH
STRENGTH OF MID AND UPPER LEVEL WLY FLOW /60-70 KTS AND 500 MB...
INCREASING TO AROUND 125 KTS AT 250/...PATTERN WILL BE FAVORABLE
FOR SUPERCELLS AND POSSIBLY TORNADOES. ALTHOUGH THIS ACTIVITY WILL
MOVE/SPREAD E BEYOND LOW LEVEL MOISTURE AXIS LATER THIS EVENING...
ADDITIONAL SEVERE STORMS MIGHT AFFECT THE SAME CORRIDOR LATER
TONIGHT AS APPROACH OF SYSTEM NOW OVER AZ ENHANCES LARGE SCALE
ASCENT ACROSS REGION...AND...ALTHOUGH CAPPING WILL LIKELY LIMIT SWD
DEVELOPMENT OF DEEP CONVECTION INTO CNTRL AR THROUGH MUCH OF THE
DAY...COLD FRONT TO THE W COULD SERVE AS A FOCUS FOR POSSIBLE
DEVELOPMENT IF BOUNDARY LAYER FLOW MAINTAINS A STRONG SLY
COMPONENT. 

...CNTRL/NRN MO INTO SRN IA/IL AND IND...
DRY SLOW ALOFT WILL ALLOW FOR SUBSTANTIAL SURFACE HEATING ACROSS
CNTRL AND NRN MO/IL LATER TODAY....AS LINGERING BOUNDARY LAYER COOL
DOME SLOWLY ERODES FROM W TO E. RELATIVELY COOL MID LEVEL
TEMPERATURES /BELOW MINUS 18/ ASSOCIATED WITH IA SHORTWAVE WILL
KEEP LAPSE RATES FAIRLY STEEP /AROUND 8 DEG PER KM/. COUPLED WITH
CONTINUING PRESENCE OF SYNOPTIC SCALE SURFACE LOW/WARM FRONT TO
FOCUS LOW LEVEL CONVERGENCE...POTENTIAL WILL BE GOOD FOR THE
DIURNAL DEVELOPMENT OF LOW-TOPPED STORMS AND POSSIBLE SUPERCELLS
WITH LARGE HAIL/HIGH WINDS AND A FEW TORNADOES. THIS ACTIVITY MAY
BE INVIGORATED AND/OR EVOLVE INTO MORE OF SQUALL LINE-TYPE SYSTEM
LATE TONIGHT AND CONTINUE EWD ACROSS NRN IND/OH LATE TONIGHT IN
RESPONSE TO INCREASING MID/UPPER LEVEL WSWLY FLOW.

...ELSW...
WITH DIFFLUENT SRN STREAM JET IN PLACE ACROSS REGION...SUFFICIENT
SHEAR AND MID LEVEL INSTABILITY PRESENT TO SUPPORT A FEW STRONG TO
SEVERE STORMS OVER PARTS OF E TN/NRN GA AND AL THIS AFTERNOON. 
BOUNDARY LAYER CLOUDS MAY...HOWEVER...KEEP CAP IN PLACE THROUGH THE
PERIOD.  
 
..CORFIDI.. 04/15/98

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