Hail and Damaging Winds in Indiana, May 22, 2011

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
212 PM EDT SUN MAY 22 2011

.AVIATION...
18Z TAFS...ONLY MINOR ADJUSTMENTS MADE TO THE 18Z TAFS WITH MAIN
CONCERN ON TIMING BETTER CHANCE OF THUNDERSTORMS FOR THE
TERMINALS. AN OLD OUTFLOW BOUNDARY FROM EARLY MORNING STORMS
ACROSS ILLINOIS HAS COMBINED WITH A WEAK UPPER DISTURBANCE EMBEDDED
IN SOUTHWESTERLY UPPER FLOW FOR BETTER COVERAGE OF SHOWERS AND
THUNDERSTORMS SOUTH OF THE TERMINALS ACROSS CENTRAL INDIANA. WHILE
AN ISOLATED SHOWER OR STORM IS POSSIBLE ESPECIALLY AT KFWA THROUGH
REMAINDER OF THE AFTERNOON...CONFIDENCE IS TOO LOW TO INCLUDE
MENTION OF TSRA UNTIL TONIGHT WHEN PREFRONTAL TROUGH/CONVERGENCE
AXIS MOVES INTO THE AREA. HAVE MAINTAINED PREVIOUS MENTION OF
THUNDER TONIGHT...MAINLY IN THE 00Z TO 06Z TIMEFRAME. CHANCE OF
THUNDERSTORMS WILL DIMINISH DURING THE OVERNIGHT/EARLY MORNING
HOURS AS SHORT WAVE TROUGH CURRENTLY ACROSS WESTERN MISSOURI
SHIFTS OFF TO THE EAST. POTENTIAL OF MORE STORMS WILL LINGER INTO
MONDAY HOWEVER AS MAIN UPPER TROUGH ACROSS THE UPPER MS RVR VALLEY
PUSHES INTO THE GREAT LAKES REGION. IN TERMS OF WINDS...FINALLY
STARTING TO SEE SOME STRONGER SOUTHERLY GUSTS MIX DOWN TO THE
SURFACE AND EXPECTING GUSTS TO AROUND 25 KNOTS THROUGH THE
REMAINDER OF THE AFTERNOON/EARLY EVENING. VFR CONDITIONS THIS
AFTERNOON WILL LIKELY GIVE WAY TO MVFR CONDITIONS OVERNIGHT AS
ANOTHER LOW LEVEL MOISTURE AXIS SHIFTS EAST INTO THE AREA
DOWNSTREAM OF MAIN UPPER LOW ACROSS THE UPPER MIDWEST.

&&

.PREV DISCUSSION... /ISSUED 1236 PM EDT SUN MAY 22 2011/

UPDATE...
CONVECTION CONTINUES THIS AFTERNOON JUST SOUTH OF THE FORECAST
AREA ACROSS CENTRAL INDIANA IN PART DUE TO RESIDUAL WEAK
BOUNDARIES LEFT OVER FROM IL CONVECTION LAST NIGHT AND DUE TO A
WEAK SHORT WAVE EMBEDDED IN UPPER FLOW TRACKING ACROSS
KENTUCKY/SRN INDIANA. THERE ALSO APPEARS TO BE ANOTHER SHORT WAVE
NOSING INTO WEST CENTRAL MISSOURI WHICH SHOULD LIFT NORTHEAST INTO
CENTRAL ILLINOIS LATE THIS AFTERNOON. SCATTERED THUNDERSTORMS MAY
CLIP SOUTHERN PORTIONS OF THE FORECAST OVER NEXT SEVERAL HOURS WITH
A MARGINAL HAIL THREAT...BUT OF GREATER CONCERN WILL BE STORMS
DEVELOPING TO THE WEST AND MOVING INTO THE AREA LATE THIS
AFTERNOON OR TONIGHT. WEAK PREFRONTAL TROUGH FROM FAR EASTERN IOWA
INTO WEST CENTRAL ILLINOIS MAY SERVE AS A FORCING MECHANISM FOR
SCATTERED THUNDERSTORM INITIATION LATE THIS AFTERNOON ACROSS
CENTRAL ILLINOIS INTO NORTHWEST INDIANA...WITH MORE WIDESPREAD
STORMS EXPECTED TO DEVELOP BACK CLOSER TO THE MS RIVER IN
ASSOCIATION WITH STRONGER VORT MAX ROTATING AROUND UPPER LOW.
AFTER THE POSSIBILITY OF SCATTERED STRONG TO SEVERE STORMS
AFFECTING THE AREA LATE AFTERNOON INTO EARLY THIS EVENING...WILL
HAVE TO WATCH EVOLUTION OF STORMS TO THE WEST...WITH MAIN CONCERN
STILL BEING DISCRETE STORMS MERGING INTO MORE LINEAR WIND THREAT
ACROSS LOCAL AREA LATER TONIGHT. NO SIGNIFICANT CHANGES TO THE
FORECAST WERE MADE AT THIS TIME.

SHORT TERM...

TODAY THROUGH MONDAY NIGHT.

UPSTREAM CONVECTION SHOULD CONT TO WANE AS STORMS BECOME MORE
DEEPLY ELEVATED WITH TIME WHILE APPROACHING PALTRY MIDLVL LAPSE
RATES AMIDST DIVERGENT 8H FLOW. GRAVITY WAVE MOVING NORTHEAST
THROUGH CWA ATTM AND OUTFLOW BNDRY NOTED SERN WI/NERN IL THROUGH
CNTL IL INTO CNTL MO. NAM/SREF COMBO USED TO TWEAK ONGOING FCST.
STACKED LOW ACRS SD TO SHIFT EWD THROUGH SHORT TERM AS PAC NW TROF
DEEPENS...WHILE PHASING WITH ENERGY DROPPING SWD ON WRN EXTNSN OF
GREENLAND-HUDSON BAY TROF AXIS...ALLOWING FOR EXTNDED PD OF MIDLVL
HGHT FALLS TO AID IN GNRL ASCENT...ESPCLY MONDAY. FOR TODAY
CONVECTION FOCUS LRGLY TIED TO PLETHORA OF BNDRIES AS WELL AS
CONVERGENCE WITH DVLPG PREFRNTL TROF ACRS MIDMSVLY MID-LATE AFTN
WITH INCRSG CHCS ACRS CWA INTO EVENING AS FEATURE MOVES EWD.
UPSTREAM THERMODYNAMICS/SHEAR PROFILE SUPPORTIVE OF SUPERCELLS AT
ONSET WITH MODERATE TURNING IN SFC-1KM LYR...THOUGH WITH TIME
ANTICIPATE MELDING INTO CLUSTERS WITH ISOLD WIND/HAIL RISK INTO
CWA AS BULK SHEAR/STABILITY/HELICITY VALUES START DOWN TREND AS
LLJ SLIDES NW OF CWA INTO ECNTL LWR MI AND LOSS OF HEATING. LATE
AFTN NAM PT SNDG DID INDICATE DECENT MDPI WITH INVERTED V PROFILE
FAVORING POTNL WET MICROBURST AND WB0 10.1KFT AND 2700-3000 J/KG
SBCAPE FOR NOD TO HAIL. AS CONFIDENCE WRT TIMING/COVERAGE
UNCERTAIN WL HOLD ON SVR MENTION IN ZONES ATTM. BUMPED TEMPS
SLIGHTLY SERN CWA WITH NEAR FULL DAY SUN IN THERMAL RIDGE. FOR
TONIGHT SQUELCHED DIURNAL COOLING GIVEN CLOUDS/SHRA/TSRA...CONTD
STRNG SRLY FLOW. WINDS VEER MONDAY...HOWEVER STRONG
DESTABILIZATION AGAIN SERN CWA AS COLD FNT STALLS ACRS SRN
CWA...BENEATH 60-65MB MID LVL JETLET INTO SWRN GRTLKS. LINEAR
STORM MODE INDICATED MONDAY WITH PARALLEL DEEP BULK SHEAR/CBL
VECTORING. DCAPE/REAR INFLOW JET INTO BACK OF STORM SEGMENTS LEND
TO WIND THREAT DY2 ERN/SERN CWA.&&

LONG TERM...

TUESDAY THROUGH SATURDAY

A POTENT NORTH PAC UPPER JET AND THE HUDSON BAY VORTEX WILL DOMINATE
THE WEATHER IN THE LONG TERM PERIOD. THIS WILL SUPPORT ABOVE NORMAL
CHANCES FOR PRECIP WITH LIKELY BELOW NORMAL TEMPS. GFS/ECMWF/GEM/AND
UKMET ALL ON THE SAME PAGE PER MAIN SYNOPTIC DETAILS IN THE PERIOD
WITH SOME VARIABILITY IN IMPULSE TIMING. MAIN SYNOPTIC INFLUENCE
WILL BE THE EASTWARD EXTENSION OF THE UPPER JET FROM ASIA ACROSS THE
PAC INTO WESTERN NOAM. TELECONNECTION TENDENCIES WOULD SUPPORT A
NEGATIVE HEIGHT TENDENCY OVER EASTERN NOAM...WHICH IS STARTING TO
BECOME MORE PROMINENT IN FORECAST MODEL RUNS. PREFERENCE IS TOWARD
THIS TENDENCY BY LATER IN THE PERIOD. THE FORECAST PERIOD WILL START
WITH A STALLED BAROCLINIC ZONE SOUTH OF THE REGION...WITH ONE OR TWO
STRONGER MID LEVEL IMPULSES EJECTING NE OUT OF THE DEVELOPING
WESTERN CONUS UPPER TROUGH. CONFIDENCE IN WAVE TIMING IS STILL WEAK
SUPPORTING A BROAD BRUSH APPROACH TO POPS FOR NOW. ALTHOUGH...ONE
PERIOD THAT CONTINUES TO SEE STRONGER SIGNALS FOR HIGHER POPS IS WED
NIGHT WHEN THE STRONGER MID LEVEL WAVE WILL ADVECT INTO THE REGION.

TUE-WED...RETAINED HIGHER POPS IN THIS PERIOD...WITH AN INCREASE IN
NUMBERS WED NIGHT GIVEN STRONGEST SIGNALS FOR MID LEVEL HEIGHT FALLS
INTO REGION IN CONJUNCTION WITH AN ASSOCIATED SFC REFLECTION. A
PERIOD OF MODERATE TO HEAVY RAIN CERTAINLY LOOKS POSSIBLE GIVEN
PROGGED PW VALUES WELL IN EXCESS OF AN INCH WITH AN OPEN GOMEX TO
THE SOUTH OF THE STALLED FRONTAL BOUNDARY.

THUR-SAT...GIVEN PREFERENCE TOWARD EASTERN CONUS NEGATIVE HEIGHT
TENDENCIES...HAVE RETAINED A LOW CHANCE POP THROUGH THE
PERIOD...MAINLY TO PRESERVE CONSISTENCY. ANY WAVE TIMING IS STILL
FAR FROM BEING RESOLVED TO TRY AND PINPOINT INDIVIDUAL 12 HOUR
PERIODS. ECMWF CERTAINLY REMAINS THE WETTEST SOLUTION WITH MUCH
SLOWER EJECTION OF THE LOWER MISSISSIPPI VALLEY UPPER LOW...A
SOLUTION THAT IS ALSO FAVORED BY THE UKMET. THIS WOULD RETAIN PRECIP
INTO THE REGION ANOTHER DAY. HOWEVER...A PREFERRED SOLUTION IS ONE IN
LINE WITH THE GEM WHICH CLEARS THIS SYSTEM OUT BY FRI. CONTINUED THE
PREVIOUS FORECAST TREND OF BELOW NORMAL TEMPS GIVEN SUPPRESSED
HEIGHTS AND A NORTHERN STREAM DOMINANT PATTERN.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&

SHORT TERM...MURPHY
LONG TERM...JC
UPDATE...MARSILI
AVIATION...MARSILI

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE NORTHERN INDIANA
620 AM EDT SUN MAY 22 2011

INZ003>009-012>018-020-022>027-032>034-MIZ077>081-OHZ001-002-004-005-
015-016-024-025-231030-
LA PORTE-ST. JOSEPH IN-ELKHART-LAGRANGE-STEUBEN-NOBLE-DE KALB-STARKE-
PULASKI-MARSHALL-FULTON IN-KOSCIUSKO-WHITLEY-ALLEN IN-WHITE-CASS IN-
MIAMI-WABASH-HUNTINGTON-WELLS-ADAMS-GRANT-BLACKFORD-JAY-BERRIEN-
CASS MI-ST. JOSEPH MI-BRANCH-HILLSDALE-WILLIAMS-FULTON OH-DEFIANCE-
HENRY-PAULDING-PUTNAM-VAN WERT-ALLEN OH-
INCLUDING THE CITIES OF...MICHIGAN CITY...LA PORTE...SOUTH BEND...
MISHAWAKA...ELKHART...GOSHEN...LAGRANGE...TOPEKA...ANGOLA...
KENDALLVILLE...LIGONIER...AUBURN...GARRETT...KNOX...NORTH JUDSON...
WINAMAC...FRANCESVILLE...PLYMOUTH...BREMEN...ROCHESTER...WARSAW...
WINONA LAKE...COLUMBIA CITY...SOUTH WHITLEY...FORT WAYNE...
MONTICELLO...BROOKSTON...LOGANSPORT...PERU...WABASH...
NORTH MANCHESTER...HUNTINGTON...BLUFFTON...OSSIAN...DECATUR...
BERNE...MARION...HARTFORD CITY...MONTPELIER...PORTLAND...NILES...
BENTON HARBOR...ST. JOSEPH...BUCHANAN...DOWAGIAC...CASSOPOLIS...
STURGIS...THREE RIVERS...COLDWATER...HILLSDALE...BRYAN...WAUSEON...
ARCHBOLD...DEFIANCE...NAPOLEON...PAULDING...ANTWERP...OTTAWA...
PANDORA...VAN WERT...DELPHOS...LIMA
620 AM EDT SUN MAY 22 2011 /520 AM CDT SUN MAY 22 2011/

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

.DAY ONE...TODAY AND TONIGHT

THERE IS A CHANCE FOR THUNDERSTORMS...ESPECIALLY LATE THIS
AFTERNOON AND EVENING...ACROSS NORTHERN INDIANA AND SOUTHWEST
LOWER MICHIGAN. THE STORMS WILL MOVE EAST...AFFECTING SOUTH
CENTRAL LOWER MICHIGAN AND NORTHWEST OHIO IN THE EVENING INTO
TONIGHT. ISOLATED DAMAGING WIND GUSTS TO 60 MPH AND ISOLATED HAIL
TO ONE INCH IN DIAMETER ARE POSSIBLE WITH THE STRONGEST STORMS.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

THERE IS A CHANCE FOR THUNDERSTORMS MONDAY THROUGH WEDNESDAY
NIGHT. SOME THUNDERSTORMS MAY BE SEVERE MONDAY...WITH DAMAGING
WIND GUSTS THE GREATEST RISK.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED LATE THIS AFTERNOON INTO
TONIGHT...AND AGAIN ON MONDAY.

&&

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

LMZ043-046-231030-
NEW BUFFALO MI TO ST JOSEPH MI-MICHIGAN CITY IN TO NEW BUFFALO MI-
620 AM EDT SUN MAY 22 2011

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE NEARSHORE WATERS OF
SOUTHEASTERN LAKE MICHIGAN.

.DAY ONE...TODAY AND TONIGHT

THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON INTO TONIGHT...
ESPECIALLY BEFORE MIDNIGHT. WIND GUSTS TO 40 KNOTS AND HAIL TO
ONE INCH IN DIAMETER ARE POSSIBLE. LOCALLY HIGH WAVES ARE POSSIBLE
IN AND NEAR STORMS.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

THERE IS A CHANCE OF THUNDERSTORMS MONDAY THROUGH WEDNESDAY.

&&

STAY TUNED TO NOAA WEATHER RADIO FOR FURTHER DETAILS OR UPDATES...OR
CHECK OUR WEB SITE AT WEATHER.GOV/IWX/?N=MARINE