Severe Thunderstorm Warning 47, NWS Northern Indiana

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
228 AM EST FRI MAY 9 2003

TODAY-SUNDAY
SFC LOW OVR SW IA WITH WARM FRONT EXTENDING ESE TO SWRN IN.
OVERRUNING TSTMS OCCURRING ATTM OVER NRN IL/IN. WARM FRONT EXPECTED TO
LIFT NE TO SRN MI BY 00Z. STRONGEST H85 THTE ADVCTN SHD BE OVER CWA
BY 12Z...MOVG NE OF THE CWA BY 18Z. STRONG FORCING AND MID LVL
INSTABILITY WILL RESULT IN SOME HAIL PRODUCING STORMS. LOCALLY HEAVY
RAIN ALSO LIKELY WITH STORMS THIS MORNING AS SOME BACK BUILDING SEEN
OVER IL ATTM AND MBE VECTOR <10KTS OVER CWA EARLY THIS MORNING. SOME
REDEVELOPMENT EXPECTED THIS AFTN AS AMS BECOMES VERY UNSTABLE IN
WARM SECTOR. FORCING MECHANISM QUESTIONABLE...BUT LEFT OVER
BOUNDARIES AND WARM FRONT LINGERING OVER NE PORTION OF CWA CUD
PROVIDE A TRIGGER.

ANOTHER STRONG TROUGH WL MOVE ACRS SRN ROCKIES TONIGHT. WEAKER S/WV
EXPECTED TO LIFT NE AHD OF THIS TROUGH INTO IL BY 12Z FRI. THIS
FORCING ALONG WITH WARM FRONT REDEVELOPING FARTHER SOUTH AS SFC LOW
DVLPS OVR SRN PLAINS CUD RESULT IN TSTMS IN CWA AGAIN OVERNIGHT...WL
KEEP IN HI CHC POPS.

SFC LOW XPCD TO DEEPEN AND MOVE TO WRN IL BY 00Z SUN. DECENT FORCING
AS WARM FRONT LIFTS INTO NRN IN AND SFC LOW APPROACHES SO HAVE
BUMPED POPS UP TO LIKELY. VERY UNSTABLE AMS EXPECTED OVER AREA AGAIN
SAT AFTN WITH BETTER DIRECTIONAL SHEAR WITH WARM FRONT MOVG
THRU...SO POTENTIAL FOR SUPERCELLS.

LOW EXPECTED TO CONT DEEPENING AND MOVE NORTH TO NRN WI BY 12Z SUN
WITH ASSOCD STRONG CDFNT SWEEPING EWD ACRS THE CWA. SQUALL LINE
EXPECTED TO DEVELOP ALONG/AHD OF FRONT. STRONG WIND FIELDS WITH SOME
DIRECTIONAL SUGGESTS SOME ROTATION WITHIN BOW ECHOES PSBL. AGAIN
PREFER A LIKELY POP.

STRONG CAA AND WRAP AROUND MOISTURE EXPECTED ACRS CWA SUNDAY AS LOW
CONTS SLOWLY NE ACRS UPR GRTLKS. WILL GO WITH WINDY/COOLER FCST WITH
LOW CHC OF SHOWERS. DJT

EXTENDED DISCUSSION...
STG LOW PRESSURE WILL MOVE FROM THE NORTHERN GREAT LAKES INTO CANADA
SUNDAY NGT AND MONDAY. STG PRESSURE GRADIENT AROUND THE LOW WILL
BRING COOL AND BREEZY CONDITIONS. GEM/GFS SHOW SERIES OF SHORTWAVES
WILL ROTATE AROUND DURING THIS PERIOD CAUSING MOSTLY CLOUDY SKIES
AND CHC OF SHOWERS. SKIES TRY TO CLEAR TUES...BUT 00Z GFS SHOWS 850
MB RHS STILL 70-80% AS MORE SHORTWAVES DROP SE IN THE NW FLOW. ALSO
500 MB TEMPS OF -20 C OR LOW WILL STILL BE IN THE AREA. COULD SEE
TUESDAY BEING MOSTLY CLOUDY AND MAYBE A CHC OF SHOWERS BUT WILL
LEAVE ALONE FOR NOW. SFC RIDGE BUILDS IN FOR WEDS INTO THURS TO
BRING A BETTER SHOT AT SUNSHINE...BUT COOL TEMPS TO CONTINUE. LWF

.IWX...
IN...NONE.
MI...NONE.
OH...NONE.

INZ003>009-012>018-020-022>027-032>034-MIZ077>081-OHZ001-002-004-005-
015-016-024-025-090945-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE NORTHERN INDIANA
441 AM EST THU MAY 8 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHERN INDIANA...NORTHWEST
OHIO AND SOUTHWEST LOWER MICHIGAN.

.DAY ONE...TODAY AND TONIGHT

A WARM FRONT WILL MOVE NORTH INTO THE REGION OVERNIGHT. SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO DEVELOP ALONG AND NORTH OF THIS FRONT
AFTER MIDNIGHT. THE GREATEST THREAT AT THIS TIME APPEARS TO BE HEAVY
RAINFALL. HOWEVER...THERE IS A SLIGHT RISK FOR THE STRONGER
THUNDERSTORMS TO BECOME SEVERE...WITH LARGE HAIL BEING THE MAIN
THREAT.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

THUNDERSTORMS WILL BE LIKELY FRIDAY MORNING...MAINLY NORTH OF US
6...IN ASSOCIATION WITH THE WARM FRONT. SOUTH OF THE FRONT...THERE
WILL BE A CHANCE FOR THUNDERSTORMS. THE STRONGEST THUNDERSTORMS WILL
BE CAPABLE OF PRODUCING LARGE HAIL AND DAMAGING WINDS. SEVERE
THUNDERSTORMS WILL BE POSSIBLE AGAIN SATURDAY AFTERNOON INTO
SUNDAY...WITH THE PASSAGE OF A COLD FRONT.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUIRED LATER TONIGHT.

STAY TUNED TO NOAA WEATHER RADIO FOR FURTHER DETAILS OR UPDATES, OR
CHECK OUR WEB SITE AT WWW.CRH.NOAA.GOV/IWX

FISHER