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150
FXUS63 KIWX 010100
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
900 PM EDT THU JUL 31 2014

.SYNOPSIS...
ISSUED AT 335 PM EDT THU JUL 31 2014

OTHER THAN A OUTSIDE CHANCE FOR A SHOWER INTO MID EVENING...DRY
AND PLEASANT CONDITIONS WILL PREVAIL ACROSS THE REGION. LOWS
TONIGHT WILL DROP INTO THE UPPER 50S TO AROUND 60. A WEAK SYSTEM
WILL APPROACH THE AREA ON FRIDAY...BRINGING A SLIGHTLY BETTER
CHANCE FOR AFTERNOON SHOWERS AND THUNDERSTORMS. HIGHS WILL CLIMB
TO AROUND 80.

&&

.UPDATE...
ISSUED AT 830 PM EDT THU JUL 31 2014

THE COMBINATION OF A WEAK LOW LEVEL CONVERGENCE AXIS ENHANCED BY
SYNOPTICALLY MODIFIED LAKE BREEZE AND A WEAK UPPER LEVEL
DISTURBANCE AIDED IN ISOLATED/SCATTERED SHOWERS AND THUNDERSTORM
DEVELOPMENT EARLIER THIS EVENING. THIS SHORT WAVE APPEARS TO BE
DEPARTING TO THE EAST...BUT ISOLATED SHOWERS MAY PERSIST OVER NEXT
FEW HOURS ALONG THIS OUTFLOW REINFORCED CONVERGENCE BOUNDARY. HAVE
MADE SOME JUST MINOR TWEAKS TO POPS TO ACCOUNT FOR DIMINISHING
SHOWER COVERAGE ALONG THIS BOUNDARY THIS EVENING. EASTWARD
EXTENSION OF UPPER LEVEL VORT MAX DROPPING OUT OF EASTERN SOUTH
DAKOTA/SOUTHERN MINNESOTA SHOULD ALSO BEGIN TO NOSE INTO WESTERN
GREAT LAKES REGION OVERNIGHT...WHICH MAY ALLOW FOR ISOLATED SHOWER
REDEVELOPMENT...PRIMARILY NORTHWEST HALF OF THE AREA.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 353 PM EDT THU JUL 31 2014

DEVELOPMENT OF CU THUS FAR HAS BEEN RELATIVELY LIMITED TO AN AREA
OF SLIGHTLY BETTER MOISTURE CONCENTRATION AND EDGE OF LAKE SHADOW.
WEAK AREA OF CONVERGENCE NOTED ON SFC OBS AT 19Z BETWEEN THE LAKE
SHADOW AREA (ROUGHLY MICHIGAN CITY TO CASSOPOLIS) AND MINOR WIND
SHIFT ( MONTICELLO TO WARSAW TO COLDWATER). FEW SHOWERS AND STORMS
WILL BE POSSIBLE THROUGH EARLY EVENING IN THIS AREA WITH AROUND
1000 J/KG OF SURFACE BASED CAPE AVAILABLE BUT SHOULD POSE NO ISSUE
WITH NO SHEAR TO ALLOW FOR ORGANIZATION. WOULDN`T BE ENTIRELY
SURPRISED TO SEE COMPLETELY DRY CONDITIONS AS WAS HINTED AT BY 00Z
4 KM SPC WRF. A PLEASANT EVENING WILL BE ON TAP WITH LOWS DROPPING
INTO THE UPPER 50S TO AROUND 60.

ALTHOUGH PESKY UPPER LEVEL LOW IN VICINITY OF JAMES BAY WILL BE
SLOWLY MOVING AWAY...THE FIRST OF 2 WAVES WILL ROUND THE BASE OF THE
TROUGH DURING THE DAY FRIDAY. CURRENT WIDELY SCATTERED ACTIVITY IN
WISCONSIN COULD DRIFT IN TOWARDS MORNING AS THE EDGE OF THE WAVE
APPROACHES. SLGT CHC HELD ONTO LATER TONIGHT BUT SE EXTENT LIMITED.
WHILE SHEAR PROFILES WILL BE UNIMPRESSIVE...MOISTURE WILL BE
SUFFICIENT ALONG WITH A QUICK SHOT OF SLIGHTLY COOLER MID LEVEL AIR
TO ALLOW FOR A SOMEWHAT BETTER CHANCE FOR SHOWERS AND THUNDERSTORMS
FRIDAY AFTERNOON. SPC DOES HAVE MUCH OF THE CWA IN A 5 PERCENT
PROB FOR PULSE TYPE STORMS FRI AFTERNOON/EVE. NOT OVERLY EXCITED
WITH SEVERE CHANCES GIVEN ENVIRONMENT IS GENERALLY THE SAME AS PAST
SEVERAL DAYS. HOWEVER...WITH A BIT BETTER UPPER SUPPORT CAN`T RULE
OUT A STRONGER STORM PRODUCING A WET MICROBURST OR MARGINAL SEVERE
HAIL. MAY FRESHEN UP HWO A BIT TO GIVE PASSING MENTION OF MARGINAL
THREAT. TEMPS WILL CLIMB TO AROUND 80...ALTHOUGH INCREASE IN CLOUDS
WITH THE SYSTEM MAY TEMPER THAT A BIT.

&&

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 353 PM EDT THU JUL 31 2014

DEEP STNRY LOW NEAR JAMES BAY EXPECTED TO BE LIFTING OUT TO THE NE
BY FRI NIGHT AND WKNG... THOUGH TROF HANGING BACK ACROSS OUR AREA
FCST TO SHARPEN UP A BIT EARLY IN THE WEEKEND AS A COUPLE OF  VORT
MAXES ROTATE THROUGH THE BASE ACROSS IL/IN. DIURNAL HEATING SHOULD
LEAD TO WK-MOD INSTABILITY WHICH MAY ALLOW SCT AFTN TSTMS TO DEVELOP.
12Z GFS HAS TRENDED A LITTLE FASTER TO MOVE UPR TROF EAST OF THE
AREA SUNDAY... IN BETTER AGREEMENT WITH LATEST/RECENT ECMWF...
SUGGESTING DRY CONDITIONS ACROSS OUR CWA ON SUNDAY. SHRTWV MOVG OVER
TOP OF WRN NORTH AMERICA RIDGE THIS AFTN IS EXPECTED TO DROP SE TO
QUEBEC BY MONDAY WITH A TRAILING BACKDOOR CDFNT MOVG INTO OR
STALLING OUT JUST NORTH OF OUR CWA. WK FORCING ALONG THE FRONT
SHOULD ALLOW FOR DRY CONDITIONS TO PERSIST IN OUR AREA THROUGH
MONDAY. BY TUE THERE MAY BE SUFFICIENT MOISTURE POOLING COMBINED
WITH A WK SHRTWV MOVG ESE ACROSS LM TO PRODUCE A FEW SHOWERS/TSTMS.
CONVECTIVE CHANCES GRDLY INCREASE WED-THU AS FLOW AMPLIFIES ONCE
AGAIN WITH BUILDING UPR RIDGE IN WRN U.S. AND DEEPENING TROF MOVG
INTO GRTLKS WITH MOISTURE/INSTABILITY FOCUSED ALONG STALLED SFC
BOUNDARY ACROSS OUR AREA.

TEMPS SHOULD BE NEAR NORMAL THROUGH THIS PERIOD. FAIRLY DRY AIRMASS
AND LIGHT FLOW SHOULD RESULT IN RATHER LARGE DIURNAL SWINGS THROUGH
THE WEEKEND WITH WARMER NIGHTS NEXT WEEK AS LOW LEVEL MOISTURE
INCREASES.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 830 PM EDT THU JUL 31 2014

ISOLATED SHOWERS AND THUNDERSTORMS ALONG OUTFLOW REINFORCED
CONVERGENCE BOUNDARY...SHOULD GENERALLY REMAIN SOUTH OF KSBN AND
NORTH OF KFWA OVER THE NEXT FEW HOURS BEFORE DISSIPATING.  ANOTHER
WEAK UPSTREAM SHORT WAVE SHOULD BEGIN TO TRACK INTO THE WESTERN
GREAT LAKES OVERNIGHT...THAT MAY ALLOW FOR ISOLATED SHOWER
REDEVELOPMENT ACROSS NORTHWEST/NORTH CENTRAL INDIANA OVERNIGHT.
WILL MAINTAIN A DRY FORECAST THROUGH THE OVERNIGHT WITH WANING
INSTABILITY AND OVERALL WEAK NATURE OF MID/UPPER LEVEL FORCING.
UPPER FORCING TO BECOME A BIT MORE PRONOUNCED ON FRIDAY AS
UPSTREAM VORT MAX VERY SLOWLY MEANDERS ACROSS THE SOUTHERN GREAT
LAKES DURING PEAK HEATING. SCATTERED SHOWERS/THUNDERSTORMS APPEAR
TO BE A GOOD POSSIBILITY ACROSS NORTHERN INDIANA FRIDAY
AFTERNOON...BUT AT THIS FORECAST DISTANCE WITH LOWER CONFIDENCE IN
OCCURRENCE AT SPECIFIC TERMINALS...WILL KEEP FORECAST DRY FRIDAY
AT THIS TIME. GENERALLY VFR CONDITIONS ARE EXPECTED...ALTHOUGH
SOME PATCHY FOG IS POSSIBLE LATE TONIGHT AND CANNOT COMPLETELY
RULE OUT SHORT LIVED MVFR VSBYS EARLY FRIDAY MORNING...BUT ONCE
AGAIN CONFIDENCE IS TOO LOW FOR INCLUSION AT THIS TIME.

&&

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

$$

UPDATE...MARSILI
SYNOPSIS...FISHER
SHORT TERM...FISHER
LONG TERM...JT
AVIATION...MARSILI


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