Area Forecast Discussion
Issued by NWS Northern Indiana

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000
FXUS63 KIWX 270218
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
1018 PM EDT SUN JUL 26 2015

.SYNOPSIS...
ISSUED AT 541 PM EDT SUN JUL 26 2015

CHANCE FOR SHOWERS AND THUNDERSTORMS IN NORTHWEST INDIANA THIS
EVENING AND FOR THE CENTRAL AND SOUTHERN PORTIONS OF THE REGION
THROUGH THE NIGHT. OTHERWISE SKIES WILL BE PARTLY CLOUDY NORTH TO
MOSTLY CLOUDY SOUTH. LOW TEMPERATURES WILL RANGE FROM THE LOWER
60S IN SOUTHERN MICHIGAN TO AROUND 70 NEAR THE OHIO RIVER. SLIGHT
CHANCE FOR SHOWERS AND THUNDERSTORMS IN THE CENTRAL AND SOUTHERN
PORTIONS OF THE REGION MONDAY WITH PARTLY CLOUDY SKIES NORTH. HIGH
TEMPERATURES MONDAY WILL BE IN THE MIDDLE TO UPPER 80S.

&&

.UPDATE...
ISSUED AT 1010 PM EDT SUN JUL 26 2015

MINOR CHANGE ON LATE EVE UPDATE WAS TO EXPAND FOG MENTION ACROSS
SRN ZONES. MUCH OF THIS AREA RECEIVED RAIN THIS EVE AND AS
MID/HIGH CLOUD DECK CURRENTLY OVER THE AREA MOVES SLOWLY EAST
OVERNIGHT... POTENTIAL FOR FOG WILL INCREASE.

&&

.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 310 PM EDT SUN JUL 26 2015

FORECAST AREA IS SANDWICHED BETWEEN DRIER E/NE FLOW IN THE NORTH AND
INSTABILITY AXIS ACROSS THE SOUTHWEST. REMNANTS OF THE MCS OVER
ILLINOIS IS GRADUALLY SHIFTING EAST AND SHOWERS ARE STRUGGLING TO
STAY TOGETHER AS THEY MOVE INTO THE NORTHERN PORTION OF THE CWA.
THE SURFACE BOUNDARY THAT EXTENDS FROM NEAR CHI/GARY ALONG US-30
INTO CENTRAL OHIO - UNSTABLE SOUTH - MORE STABLE NORTH.

WHILE THE MODELS ARE GENERALLY IN AGREEMENT THAT THE CONVECTION
/ PRECIPITATION REMAINS OUT OF THE AREA...HAVE INCLUDED LOW
CHANCE POP AND ISOLD SHRA/T IN THE NEAR TERM FORECAST. DO NOT
ANTICIPATE WELL ORGANIZED CONVECTION WITH THESE SHOWERS...BUT LIKE
LAST NIGHT/EARLY THIS MORNING IT IS NOT TAKING MUCH TO PRODUCE
MODERATE TO HEAVY RAINFALL.

VERTICAL PROFILES SHOW BEST SHEAR CONTINUES SOUTH AND WEST...WITH
LITTLE TO NO SHEAR OVER THE FORECAST AREA. THUS EXPECT THAT ANY
SHOWERS THAT FORM WILL BE SHORT LIVED AND SLOW MOVING.

OVERNIGHT...EXPECT TO SEE ANOTHER ROUND OF PATCHY FOG FORMATION
ALONG THE MOISTURE AXIS - ALONG AND CLOSE TO US 30. SHOULD DEVELOP A
FEW HOURS BEFORE SUNRISE AND DISSIPATE QUICKLY AFTER SUNRISE.

OTHER CONCERN WILL BE THE INCREASED TEMPERATURES AND HUMIDITY.
EXPECT TO SEE HEAT INDICES RISE TO NEAR 90 DURING THE DAY MONDAY.
THIS IS WELL BELOW HEAT ADVISORY CRITERIA...SO NO HEADLINES.

&&

.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 310 PM EDT SUN JUL 26 2015

MONDAY NIGHT THROUGH TUESDAY NIGHT WILL FEATURE MAINLY
DRY/WARM CONDITIONS AS MID LEVEL HEIGHTS CONTINUE TO SLOWLY
RISE IN RESPONSE TO A ROUND OF HEIGHT FALLS SHIFTING INTO THE
NORTHERN PLAINS. THIS WILL HELP MAINTAIN WEAK LOW LEVEL RIDGING
ACROSS THE CENTRAL/EASTERN GREAT LAKES AND HOLD A DIFFUSE FRONTAL
BOUNDARY IN PLACE FROM THE UPPER MIDWEST SSE INTO ILLINOIS. CHANCES
FOR MCS REMNANTS (OR ISO-SCT CONVECTION TIED TO THE AFTN-EVE DIURNAL
CYCLE ALONG INSTABILITY GRADIENT/THETA-E RIDGE) SHOULD MAINLY REMAIN
FOCUSED WEST OF THE IWX CWA...ALTHOUGH WILL NEED TO MONITOR AREAS
MAINLY WEST OF HWY 31 FOR RAIN CHANCES GIVEN CLOSE PROXIMITY TO
ELEVATED PORTION OF FRONT.

STRONG UPPER TROUGH/SFC REFLECTION LIFTING NE INTO ONTARIO AND
ASSOCIATED MID LEVEL TROUGH AXIS EXTENDING SE THROUGH THE GREAT
LAKES REGION WILL FORCE A SEASONABLY STRONG COLD FRONT THROUGH THE
AREA WEDNESDAY INTO WEDNESDAY EVENING. LOW LEVEL MOISTURE ADVECTION
IN ADVANCE OF FRONT WILL BE MORE THAN SUFFICIENT FOR
CONVECTION...BUT WITH STRONGER DEEPER LAYER FLOW/SHEAR LAGGING
FRONT...AND MINOR TIMING DIFFERENCES IN MODEL GUIDANCE...FELT
PRUDENT TO HOLD WITH MID CHANCE POPS DURING THIS TIME.

QUIET/LESS HUMID WX EXPECTED POST-FRONTAL THURSDAY INTO FRIDAY UNDER
WNW FLOW ALOFT. NON-ZERO PRECIP CHANCES RETURN BY NEXT WEEKEND AS
THERE IS SOME MODEL AGREEMENT IN DROPPING A FEW LOWER AMPLITUDE
SHORTWAVES THROUGH THE LOWER LAKES.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 755 PM EDT SUN JUL 26 2015

LITTLE CHANGE TO PREVIOUS TAFS. AREA OF RAIN OVER CENTRAL INDIANA
SHOULD REMAIN SOUTH OF THE TERMINALS THIS EVE WITH MAINLY JUST
SOME MID/HIGH CLOUDS. LOW LEVELS REMAIN VERY MOIST. EASTERLY
GRADIENT WINDS WILL BE LIGHT OVERNIGHT BUT SHOULD BE A LITTLE
STRONGER THAN LAST NIGHT. ALSO WITH NO RAINFALL EXPECTED AT THE
TERMINALS TONIGHT, GOING MVFR BR FCST (AS OPPOSED TO SUNDAY
MORNING`S OBSERVED LIFR FG) MAINTAINED AT FWA AROUND DAYBREAK
MONDAY.


&&

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

$$

UPDATE...JT
SYNOPSIS...LOTHAMER
SHORT TERM...LEWIS
LONG TERM...STEINWEDEL
AVIATION...JT


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