Area Forecast Discussion
Issued by NWS Northern Indiana

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000
FXUS63 KIWX 021047
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
647 AM EDT SUN AUG 2 2015

.SYNOPSIS...
ISSUED AT 322 AM EDT SUN AUG 2 2015

AN UPPER LEVEL DISTURBANCE AND STRONG COLD FRONT CROSSING THE
GREAT LAKES TONIGHT WILL SPARK SHOWERS AND THUNDERSTORMS...SOME
STRONG TO POTENTIALLY SEVERE. AHEAD OF THIS SYSTEM...A WARM AND
WINDY DAY IS EXPECTED WITH AFTERNOON HIGHS FROM THE UPPER 80S TO
LOWER 90S.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 322 AM EDT SUN AUG 2 2015

STORMY LT PD SHAPING UP. RTN OF VRY WARM AND HUMID CONDS XPCD
THIS AFTN IN ASSOCN/W EWD FOLD OF STAUNCH PLAINS THERMAL RIDGE.
GIVEN XPCD SUBSTANTIAL CLRG WITHIN DEEPENING WARM SECTOR SEWD OF
INTENSIFYING SFC FNTL ZONE SHIFTING OUT OF THE UPR MIDWEST AND
SUBSTANTIAL MIXING THIS AFTN...DECIDED PREFERENCE LIES TWD WARMER
SPECTRUM OF GUIDANCE TEMPS ESP AFT LOOKING AT VARIOUS 2M PROGS AND
WILL BUMP ACCORDINGLY. OTRWS POPS/WX NIL AS CAPPING ALOFT
INTENSIFIES OVERTOP INITIALLY DRIER POCKET OF LL THETA-E.

PRIMARY ATTN THOUGH CNTRD ON SEWD SINKING ACTIVE FNTL ZONE TONIGHT.
BY ALL ACCOUNTS FORCING WITHIN INTENSIFYING SFC FNTL ZONE ALIGNED
W/ROBUST HGTS FALLS ALOFT AND SIG LL MSTR ADVTN OUT OF THE CORN BELT
TWD 00Z POINT TO WHAT SHLD BE A SOLID LINE OF STG-SVR CONVN SHIFTING
SWD OUT OF MI THIS EVENING. SRN REACH OF SVR THREAT IN DOUBT HWVR
TIED TO LT EVENING TIMING AND STABILIZING BNDRY LYR BUT NRN THIRD
COULD GET WALLOPED W/SIG SVR PENDING UPSTREAM EVOLUTION OF CONV
LINE UNDERNEATH STEEP EML LTR THIS AFTN. WILL HOLD W/PRIOR 60 POP
THRESHOLD THOUGH AS BOTH NR AND SHRT TERM GUIDANCE VACILLATES CONSIDERABLY
W/FAR DIFFERING CONVN SCENARIOS.

&&

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 322 AM EDT SUN AUG 2 2015

A TREND TOWARD BELOW NORMAL TEMPS THE MAIN STORY NEXT WEEK AS
PRIMARY BAROCLINIC ZONE SETTLES SOUTH INTO THE OHIO/MID MS VALLEYS
IN RESPONSE TO HUDSON/JAMES BAY UPPER LOW DRIFT INTO SOUTHEAST
CANADA...

ROUND OF HEIGHT FALLS THROUGH THE GREAT LAKES REGION IN THIS
TRANSITION WILL FORCE A SYNOPTIC COLD FRONT AND ASSOCIATED
DIMINISHING SHOWER/STORM CHANCES SE THROUGH THE LOCAL AREA MONDAY
MORNING. DRY/STABLE POST-FRONTAL NORTHWEST FLOW THEN FILTERS IN FOR
LATER MONDAY-TUESDAY.

PRIMARY UPPER TROUGH AXIS LOOKS TO RELAX/SHIFT EAST BY MID TO LATE
WEEK WHICH WILL ALLOW BETTER POTENTIAL FOR UPSTREAM SHORTWAVES TO
TAKE AIM ON THE REGION. RESULTING FGEN/ISENTROPIC ASCENT RESPONSE
ALONG THE AFOREMENTIONED FRONTAL SLOPE...ALONG WITH LINGERING RIGHT
ENTRANCE UPPER JET SUPPORT...WARRANT PERIODIC RAIN CHANCES WITH WEAK
FRONTAL WAVES DURING THE WEDNESDAY THROUGH EARLY FRIDAY PERIODS.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 647 AM EDT SUN AUG 2 2015

VFR CONDS XPCD THROUGH MUCH OF THIS PD. HWVR SHARPENING
CDFNT IN ASSOCN/W VIGOROUS DISTURBANCE OVR SRN ONTARIO XPCD TO SURGE
SEWD LT PD...SPARKING A LINE OF VIGOROUS CONVN OVERNIGHT. TIMING
UNCERTAINTIES REMAIN THOUGH IN BOTH NR AND SHRT TERM GUIDANCE AND AS
SUCH HAVE ONLY INCLUDED A VCTS MENTION INVOF TERMINALS. OTRWS STG
MIXING XPCD TO DVLP WITHIN WARM SECTOR SEWD OF ADVG LOW PRES THIS
AFTN. CORRESPONDING RAPID ESCALATION OF LL FLW AND SIG MOMENTUM XFER
SUGGESTS SWRLY SFC GUSTS AOA 25KTS FOR MUCH OF THIS AFTN.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...BEACH HAZARDS STATEMENT FROM 10 AM EDT THIS MORNING THROUGH
     MONDAY MORNING FOR MIZ077.

OH...NONE.
LM...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 8 AM EDT MONDAY
     FOR LMZ043.

     SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 11 PM EDT THIS
     EVENING FOR LMZ046.

&&

$$

SYNOPSIS...T
SHORT TERM...T
LONG TERM...STEINWEDEL
AVIATION...T


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