Area Forecast Discussion
Issued by NWS Northern Indiana

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000
FXUS63 KIWX 261917
AFDIWX

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

.SYNOPSIS...
ISSUED AT 352 AM EDT SUN JUL 26 2015

ISOLATED SHOWERS AND THUNDERSTORMS WILL FORM ALONG AND SOUTH OF US
ROUTE 30 THIS EVENING...ENDING AROUND MIDNIGHT. AS HIGH PRESSURE
BUILDS OVER THE REGION MONDAY AND TUESDAY EXPECT TEMPERATURE AND
HUMIDITY TO INCREASE. MORE ORGANIZED SHOWERS AND THUNDERSTORMS
WILL AFFECT THE AREA MID-WEEK AS A COLD FRONT APPROACHES. LOW
TEMPERATURES TONIGHT WILL DROP BACK INTO THE MID TO UPPER 60S.
HIGHS ON MONDAY WILL BE IN THE MID TO UPPER 80S.

&&

.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 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 310 PM EDT SUN JUL 26 2015

(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED
AT 119 PM EDT SUN JUL 26 2015

DRIER LOW LEVEL EASTERLY FLOW HAS KEPT CU FIELD FROM ADVANCING TO
FAR NORTH TODAY AND THIS WILL PERSIST THROUGH THE FORECAST PERIOD.
EXPECT TO SEE VFR CONDITIONS THROUGH MUCH OF THE AFTERNOON AND
OVERNIGHT. WITH LIGHT WINDS AND LOW/NEAR SURFACE MOISTURE STILL
TRAPPED...HAVE INCLUDED A BRIEF PERIOD OF LOWER VSBY AT KFWA
AROUND SUNRISE MONDAY.

&&

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

$$

SYNOPSIS...LEWIS
SHORT TERM...LEWIS
LONG TERM...STEINWEDEL
AVIATION...LEWIS

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