Area Forecast Discussion
Issued by NWS Northern Indiana

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000
FXUS63 KIWX 272324
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
724 PM EDT WED AUG 27 2014

.SYNOPSIS...
ISSUED AT 321 PM EDT WED AUG 27 2014

HIGH PRESSURE WILL REMAIN IN CONTROL THROUGH FRIDAY
AFTERNOON...KEEPING WEATHER QUIET. A LOW PRESSURE SYSTEM PASSING
THROUGH THE GREAT LAKES THIS WEEKEND WILL BRING SHOWERS AND
THUNDERSTORMS TO THE REGION. LOWS TONIGHT WILL BE IN THE 50S.
HIGHS ON THURSDAY WILL BE IN THE UPPER 70S AND LOW 80S.

&&

.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 321 PM EDT WED AUG 27 2014

TRANQUIL WX XPCD THIS PD AS HIGH PRES BLDS THROUGH THE ERN LAKES.
N/NERLY LL FLW WILL CONT TO ADVT IN MUCH DRIER AIR W/SFC TDS FALLING
IN THE 50S TONIGHT. WILL TWEAK TEMPS OVERNIGHT A BIT HWVR IN LIGHT
OF UPSTREAM EWD SPILLAGE OF MID/HIGH CLDS. OTRWS PLEASANT WX XPCD TO
CONT ON THU.

&&

.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 321 PM EDT WED AUG 27 2014

A 500MB RIDGE EXPANDING NORTHWESTWARD FROM THE SOUTHEASTERN CONUS
WILL KEEP WEATHER QUIET THURSDAY NIGHT BEFORE MORE ACTIVE WEATHER
RETURNS FOR THE WEEKEND. SURFACE HIGH PRESSURE WILL LINGER OVER
LOWER MI AND THE OHIO VALLEY THROUGH LATE THURSDAY EVENING BEFORE
DRIFTING INTO THE NEW ENGLAND STATES.

MEANWHILE...A TROUGH OVER THE SOUTHWESTERN U.S. TODAY WILL DRIFT
EASTWARD INTO THE CENTRAL PLAINS AND MERGE WITH A SHORTWAVE CROSSING
THE NORTHERN PLAINS BY FRIDAY AFTERNOON...THEN LIFT NORTHEASTWARD
INTO NORTHERN LOWER MI AND SOUTHERN ONTARIO BY SUNDAY MORNING. THIS
WILL BRING A SURFACE TROUGH AND LOW PRESSURE CENTER ACROSS THE GREAT
LAKES REGION THROUGH THE WEEKEND.

ON FRIDAY...THE CWA REMAINS UNDER THE EXITING HIGH PRESSURE RIDGE
THROUGH THE EARLY AFTERNOON. ADDITIONALLY...THE BEST MOISTURE
TRANSPORT/CONVERGENCE FOCUSES ALONG AN AXIS TO THE NORTH OF THE CWA
AS THE CENTER OF WEAK SFC LOW DEVELOPS OVER MN/WI/IOWA FRIDAY
MORNING. THINK THE RIDGE WILL SUPPRESS ANY PRECIPITATION FOR THE
FIRST PORTION OF THE DAY. AS HIGH PRESSURE EXITS TO THE EAST LATE
FRIDAY AFTERNOON AND EVENING...THE WARM FRONT ASSOCIATED WITH THE
SFC LOW LIFTS NORTHEASTWARD ACROSS THE GREAT LAKES. GIVEN WEAK
ISENTROPIC ASCENT ON THE 310K SFC AND 1-2K J/KG OF MUCAPE EXPECT
CHANCES FOR SOME SHOWER/T STORM DEVELOPMENT.

SATURDAY INTO SUNDAY THE MAIN UPPER LEVEL TROUGH/ASSOCIATED SURFACE
LOW LIFTS FROM THE CENTRAL PLAINS INTO ONTARIO. BEST FORCING/PER
850-500MB QVECTOR CONVERGENCE AND STRONG ISENTROPIC ASCENT AT 305K/
MOVES THROUGH SATURDAY THROUGH SUNDAY MORNING. AS A RESULT...HAVE
HIGH CHANCE TO LIKELY POPS ACROSS THE AREA THROUGH THIS TIME. KEPT
THUNDERSTORMS IN AS WELL GIVEN DECENT INSTABILITY...ESPECIALLY FOR
SUNDAY AFTERNOON WHERE MODELS SUGGEST UPWARDS OF 2000 J/KG OF MUCAPE
FOR THE WESTERN AND SOUTH CENTRAL PORTIONS OF THE CWA. AS FAR AS
SEVERE CHANCES THINKING THEY WILL BE FAIRLY LIMITED GIVEN WEAK 0-6
KM SHEAR...BUT THE POTENTIAL FOR HEAVY RAIN IS MORE SIGNIFICANT.
WITH PWATS BETWEEN 1.5 AND 2 INCHES...AND CORFIDI VECTORS ORIENTED
PARALLEL TO THE APPROACHING FRONTAL BOUNDARY SAT AFT/SAT EVE COULD
SEE FLOODING PROBLEMS AS THE FRONT APPROACHES...MAINLY IN THE
NORTHWESTERN AND CENTRAL CWA.

SUNDAY NIGHT A BRIEF RIDGE ALOFT WILL SLIDE INTO THE CWA BEHIND THE
EXITING SHORTWAVE/SFC LOW PRESSURE TROUGH...ALLOWING FOR A BRIEF
BREAK IN PRECIPITATION. BY LATE MONDAY MORNING...A MORE POTENT
TROUGH WILL AID IN THE DEVELOPMENT OF A SURFACE LOW OVER MINNESOTA.
THIS LOW WILL LIFT NORTHEASTWARD INTO HUDSON BAY BY TUESDAY
MORNING...BRINGING A SURFACE TROUGH/COLD FRONT ACROSS THE GREAT
LAKES REGION FOR THE START OF THE WORK WEEK. MOISTURE
CONVERGENCE/STRONG ISENTROPIC ASCENT AT 305-310K ARE IN PLACE MONDAY
AFTERNOON THROUGH LATE TUESDAY MORNING...SO HAVE KEPT THE GOING
HIGHER CHANCE POPS FOR THAT TIME PERIOD. STORMS LATE MONDAY
AFTERNOON COULD BECOME SEVERE...WITH AROUND 1500-2000 J/KG MUCAPE
AND 30-50 KTS 0-6 KM SHEAR OVER MUCH OF THE CWA. KEPT CONSENSUS
CHANCE POPS IN FOR TUESDAY...WHICH WILL MAINLY BE IN THE MORNING
WITH THE EXITING FRONT.

HIGH PRESSURE BUILDS IN BY TUESDAY EVENING UNDER RELATIVELY ZONAL
FLOW ALOFT...AND WILL DRIFT ACROSS THE OHIO VALLEY THROUGH THURSDAY
NIGHT. BOTH THE GFS/ECMWF HAVE HIGH PRESSURE HOLDING STRONG...SO
PULLED CONSENSUS SLIGHT CHANCE/CHANCE POPS TUESDAY NIGHT AND
WEDNESDAY.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 715 PM EDT WED AUG 27 2014

GENERALLY EXPECT VFR CONDITIONS FOR THIS PERIOD. EXCEPTION WILL BE
NEAR DAYBREAK AS MVFR BR FORMATION WILL BE POSSIBLE...ESPECIALLY
AT KFWA. OTHERWISE JUST A BKN-OVC CIRRUS CANOPY WITH NORTHEAST TO
EAST WINDS UNDER 10 KNOTS.

&&

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

$$

SYNOPSIS...MCD
SHORT TERM...T
LONG TERM...MCD
AVIATION...LASHLEY


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