Severe Thunderstorm Warning 218, NWS Springfield, MO

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SPRINGFIELD MO
333 AM CDT WED JUL 4 2001

PROBLEMS CONT TO BE TEMPORAL AND SPATIAL FORECAST OF MCS(S).

LATEST KEAX AND KSGF 88D SHOW MCS DROPPING SEWD INTO THE NRN THIRD
OF THE CWFA AS OF 04/0745Z. TSTMS WERE DVLPG WWD...AT A SLOW PACE...
JUST NORTH OF VERNON CO. TSTM DVLPMT HAS BEEN MORE AGGRESSIVE FROM
STJ TO NR SZL. THINK THAT 700MB E-W THERMAL RIDGE IS AGAIN AFFECTING
TSTM PROPAGATION AND DVLPMNT...SIMILAR TO 24 HRS AGO. 04/00Z 700MB
ANALYSIS OF TEMP SHOWED THERMAL AXIS FROM NRN KS...TO NR MKC...AND
TO NR COU. THUS MCS HAS BEEN ACCRUING BETTER WWD DVLPMNT NORTH OF
THE 700MB THERMAL AXIS...WHILE STORM DVLPMNT HAS BEEN SLOWER SOUTH
OF THIS THERMAL AXIS. THIS THERMAL AXIS IS FUNCTIONING AS A MID-LVL
CAP.

PROBLEM FOR TODAY IS HOW FAR WEST WILL THIS MCS DVLP AND WHERE WILL
NEXT MCS DVLP LATER TODAY OR TONIGHT. OTHER PROBLEM IS TSTM DVLPMT
THIS AFTERNOON ALONG OUTFLOW BOUNDARY.

LATEST KSGF 88D SHOWED OUTFLOW BOUNDARY FROM MCS...EXTENDED FROM
NEVADA...TO JUST NORTH OF SGF...AND TO SRN WRIGHT COUNTY. BOUNDARY
WILL CONT TO SLIP SWD INTO THE SRN PTN OF CWFA TODAY. MODELS ARE
HAVING PROBLEMS WITH THE QUANTITY OF PCPN FCST...BUT SOMEWHAT CLOSE
IN AREAL PLACEMENT. AVN APPEARS TO HAVE BETTER HANDLE ON SITUATION
AS AVN HAD BETTER FCST OF 850MB WIND FLOW AT 04/06Z. AVN WAS ALSO
CONSISTENT WITH PREV AVN RUN AND PREV RUN OF ETA MODEL WITH RESPECT
TO SHORT WAVE TROF OVER KS ON THURS.

AVN FCSTS THE 700MB THERMAL AXIS TO SHIFT SWD TODAY. THIS SHOULD
ALLOW CURRENT MCS TO CONT MOVG SEWD. SINCE THE EASTERN MOST END OF
THE THERMAL AXIS WILL HAVE LESS CAP STRENGTH...IT APPEARS THE ERN
HALF OF CWFA WILL SEE TSTMS FOR PART OF TODAY...AS MCS SLIDES SEWD
THIS MORNING BEFORE EXITING INTO NRN/NERN AR BY EARLY AFTERNOON.
WESTERN END OF THERMAL AXIS WILL PROVIDE ENUF OF A CAP THAT THE WSTRN
COUNTIES WILL PROBLY NOT SEE MUCH PCPN FROM THIS MCS. HOWEVER WITH
AVN FCSTG WIND SHIFT LINE OVER THE SRN CWFA...THIS WOULD COINCIDE
WITH OUTFLOW BOUNDARY...THERE WILL BE A BOUNDARY TO FOCUS CONVECTION
AT TIME OF PEAK HEATING TODAY. WITH SFC DWPTS NR 70...WEAK
CONVERGENCE ALONG OUTFLOW BOUNDARY...AND SFC BASED CAPE OF 2400 J/KG
...THERE IS A PSSBLTY OF A FEW TSTMS DVLPG OVER THE SRN COUNTIES LATE
THIS AFTN. SOME OF THE STORMS COULD BE PULSE TYPE SEVERE.

OTHERWISE LIFTED INDEX PROG...SHOWS POSN OF SYNOPTIC SCALE COLD FRONT
WELL TO THE NORTH OF THE AREA TODAY. THIS LOOKS CORRECT GIVEN FRONTS
POSN WITH RESPECT TO UPPER LEVEL JET. THIS FACT IS TO DIFFERENTIATE
THE BOUNDARY OVER SRN MO FROM THE SYNOPTIC SCALE COLD FRONT.

SITUATION FOR TONIGHT LOOKS LIKE ONE OF A WAITING GAME. OUTFLOW
BOUNDARY WILL LIFT SLGTLY NWD...WITH BOUNDARY CURVING NWWD INTO
CNTRL KS. LEE SIDE LOW PRESSURE WILL INCRS WAA OVER CNTRL KS AND
OVER THE BOUNDARY. NEW CONVECTION EXPECTED TO DVLP INTO AN MCS
OVER CNTRL KS TNGT AND WILL GAIN STRENGTH WITH THE ARRIVAL OF SHORT
WAVE TROF TOWARDS 05/12Z. AVN FCSTS THE CONDITIONS ASSOC WITH MCS
TO REACH THE FAR WESTERN COUNTIES BY EARLY THURS AM.

THURSDAY LOOKS LIKE A STORMY ONE. AVN FCST SHORT WAVE TROF TO XTRM
SERN KS BY 06/00Z THURS EVENING. BELIEVE THAT THURS AM MCS WILL LOSE
STRENGTH WHILE MOVING ACROSS CWFA DURG THE DAY. HOWEVER BACK
BUILDING LIKELY TO ENSUE AS SHORT WAVE TROF APPROACHES. BEST UVV FROM
PVA WILL FOCUS NEW CONVECTION OVER SERN KS AND SWRN AND SCNTRL MO
INTO THURS NGT.

SPECIAL NOTE REGARDING THIS SHORT WAVE TROF IS IN ORDER. THIS SHORT
WAVE MAY BE OVERDEVELOPED BY 04/00Z AVN AND 03/18Z AVN. HOWEVER
THIS SHORT WAVE WAS PROGGED BY 03/12Z ETA ALTHOUGH SOMEWHAT WEAKER.
04/00Z ETA DOES NOT DEPICT ANY SHORT WAVE TROF ON THURS...A DEPARTURE
FROM 03/12Z RUN. HAVE SOME CONFIDENCE IN AVN SOLN DUE TO CONSISTENCY
FROM TWO RUNS...THE 04/00Z CANADIAN MODEL DEPICTS SHORT WAVE...LATEST
WATER VAPOR IMAGERY SHOWED A LARGE AREA OF ENHANCEMENT OVER THE STATE
OF NEVADA AT 04/0015Z...THIS ENHANCED CLOUD REGION WAS NORTH AND
NORTHWEST OF 04/00Z AVN VORT MAX POSN.

SHORT WAVE TROF IS FCST TO MOVE SOUTH OF THE MO/AR BORDER BEFORE
06/12Z FRIDAY MORNING. SO THAT FRIDAY SHOULD BE PCPN FREE OVER THE
CWFA.

MAV POPS LOOK CLOSER TO THE MARK WHILE FWC LOOKS TOO WEAK WITH POPS.

WILL MAKE ADJUSTMENTS TO PCPN TIMING AND POPS BUT WILL PROBLY NOT
CHANGE HIGH AND LOW TEMPS MUCH FROM PREV FCST. NOT SURE YET IF
ADJUSTMENTS ARE NECESSARY ON THE EXTENDED...WILL TAKE LOOK AT LATEST
MRF AND DECIDE THEN.

.SGF...
MO...NONE.
KS...NONE.

D.STEINMETZ