Severe Thunderstorm Warning 52, NWS Northern Indiana

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
231 PM EST SUN JUN 10 2001

FCST PROBLEM CONTS TO BE TSRA CHANCES THROUGH FCST PACKAGE.
AGAIN USING A BLEND OF ETA/AVN MODELS...WITH AN EMPHASIS ON RUC40
THIS EVENING.

MCV MOVING ACRS WI THIS AFTN CONTS TO TRIGGER LINE OF TSRA.
CONVECTION ALSO FIRING FM NRN MI TO NW OH ALONG WEAK WMFNT AND
THETA E MAX. TEMPERATURES ACRS FA HAVE RISEN TO AROUND 80 THIS AFTN
WITH DWPTS AROUND 60.

FIRST FCST PROBLEM WL BE POPS TNGT. DEEPEST MOISTURE AND BEST
FORCING WL BE POINTED N OF FA WHERE WI CONVECTION SHOULD MOVE.
PROXIMITY TO NRN COUNTIES WARRANT A CONTINUED CHC THAT AREA.
CURRENTLY WATCHING A COUPLE BOUNDARIES IN VIS IMAGES ACRS ERN
IA...SW WI AND NW IL. MSAS SHOWING A COUPLE THETA E RIDGES AHEAD OF
THESE BOUNDARIES. RUC40 HAS BEEN CONSISTENT WITH DEVELOPMENT OF OMEGA
LATE THIS AFTN ACRS IL INTO WRN INDIANA THIS EVENING. LATEST RUC40
SHOWS VERY GOOD 850MB THETA E RIDGE AND ADVECTION INTO WRN FA BY
03Z. WITH SML CHC POPS IN CURRENT FCST AND ABOVE FACTORS...WL CONT
THE LOW CHC POPS TNGT. LATEST SWOMCD FOR IL/IA/WI CONFIRMS THIS
THINKING.

MONDAY CONTS TO LOOK LIKE A HIGHLY UNSTABLE DAY WITH NO TRIGGER IN
MODELS TO INITIATE CONVECTION. HOWEVER...WITH OUTFLOWS FM NRN
CONVECTION...WEAKENING SFC FNT AND CAPES OF 3000 J/KG...WL NOT
TAKE MUCH TO GET THINGS GOING IN AFTN. ANY STORMS THAT DO FIRE WL
HAVE POTENTIAL TO BECOME SVR GIVEN AMOUNT OF INSTABILITY. ETA AND
MESO ETA AND NOW EVEN AVN HAVE BEEN SHOWING A RATHER WEAK LOOKING
VORT MAX MOVING OVR FA DURING AFTN. THETA E RIDGE AT SFC AND 850
REMAIN PARKED OVR CENTRAL FA. OTHER NEGATIVE FACTOR IS RIDGING
BUILDING INTO FA ALOFT DURING AFTN...BUT THERE IS SOME UPPER LEVEL
DIVERGENCE AHEAD OF RIDGE. GIVEN HIGHLY UNSTABLE ATMS...WL AGAIN
CONT WITH LOW CHC POPS.

RIDGING INCREASES TUE AND WED. WL DRY FCST OUT FM SOUTH TO NORTH
THROUGH WED. CHC POPS AGAIN FOR THU AS TROPICAL REMNANTS GET
CAUGHT BETWEEN APCHG PLAINS TROF AND ATLANTIC RIDGE. AVN MOVES
SYSTEM DUE NORTH AND AVN TENDS TO HANDLE TROPICAL SYSTEMS BEST OF
THE SHORTER RANGE MODELS. LATEST 120 HR AVN APPEARS A LITTLE SLOWER
WITH SFC FNT FOR FRI. GIVEN ATLANTIC HIGH AND NWRD MOVING MOISTURE...
WL ADD PCPN CHANCES FOR FRI. WL KEEP REMAINDER OF EXTENDED FCST DRY.

GUIDANCE TEMPS SHOWING A VERY SIGNIFICANT WARM UP BY TUE WITH 90S
PROGGED ACROSS MOST OF FA BY FWC AND MAV. WITH INCREASING LOW LEVELy
MOISTURE PREFER TO TEMPER WARM UP JUST A TAD AND KEEP MOST AREAS
AT OR JUST BLO 90. AT ANY RATE...AFTER SUCH AN EXTENDED COOL AND WET
PERIOD...WL FINALLY FEEL LIKE SUMMER.

.IWX...NONE.

LASHLEY