Area Forecast Discussion
Issued by NWS Northern Indiana

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000
FXUS63 KIWX 300603
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
203 AM EDT TUE JUN 30 2015

.SYNOPSIS...
ISSUED AT 813 PM EDT MON JUN 29 2015

LITTLE MORE THAN AN ISOLATED LIGHT SHOWER OR TWO IS EXPECTED
OVERNIGHT...OTHERWISE MOST AREAS WILL BE DRY FOR A CHANGE. PATCHY
FOG MAY FORM TOWARD DAYBREAK...ESPECIALLY IN THE MOST WET AREAS.
THERE IS ANOTHER CHANCE FOR SHOWERS AND THUNDERSTORMS ON TUESDAY
AS AN UPPER LEVEL SYSTEM ROTATES ACROSS THE REGION. LOWS OVERNIGHT
WILL DROP INTO THE UPPER 50S AND LOWER 60S. HIGHS ON TUESDAY WILL
BE IN THE 70S.

&&

.UPDATE...
ISSUED AT 122 AM EDT TUE JUN 30 2015

QUICK GRID PATCHUP PRIOR TO MORNING PACKAGE TO BRING IN OUTSIDE
CHANCE OF SHOWER OR STORM A FEW HOURS FASTER IN WESTERN AREAS.
KLOT RADAR SHOWING AN AREA OF SCATTERED SHOWERS AND THUNDERSTORMS
ROTATING ESE TOWARD WESTERN PARTS OF THE FORECAST AREA. NOT SURE
EXACTLY WHAT SHAPE THEY MAY BE WHEN THEY ARRIVE WITH IR SAT
FINALLY SHOWING SOME WARMING OF CLOUD TOPS. MAY END UP THAT THEY
FALL APART ENTIRELY BUT DIDN`T FEEL COMFORTABLE WITH A "DRY"
FORECAST AFTER 8Z TO SPEED UP TIMING A TOUCH. OTHER CHALLENGE IS
HANDLING OF SKY COVER AS STRATUS DECK WAS SLOWLY ATTEMPTING TO
EXPAND/DEVELOP ACROSS MUCH OF THE AREA. DIDN`T MAKE MANY CHANGES
WRT TO SKY COVER AS GRIDS WERE OVERALL IN DECENT SHAPE.

&&

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 320 PM EDT MON JUN 29 2015

SHORT WAVES EMBEDDED WITHIN LARGE SCALE TROUGH HAVE BEEN
RESPONSIBLE FOR TODAYS RAINFALL. DEFORMATION AREA IN BASE OF
TROUGH OVER NW INDIANA HAS BEEN SLOW TO MOVE EAST AND WEAKEN BUT
FINALLY SHOWING SIGNS LAST HOUR OR SO. WITH CONTINUED WEAK DIURNAL
HEATING AND UPPER TROUGH EXPECT SCATTERED SHOWERS AND AN ISOLATED
TSRA THROUGH EARLY EVENING BEFORE LOSS OF HEATING LEADS TO
DIMINISHING SHOWERS. THEN EXPECT VARIABLE CLOUDS OVERNIGHT BUT
MOIST LOW LEVELS AND LIGHT WINDS WILL ALLOW FOR SOME PATCHY FOG
DEVELOPMENT ESPECIALLY WHERE SKIES CLEAR. THIS COULD LEAD TO MORE
STRATUS DEVELOPMENT AS WELL TOWARD DAYBREAK AS WELL.

ANOTHER SHORT WAVE WILL DROP INTO THE AREA TUESDAY. HIRES
CONVECTIVE MODELS INDICATE SOME DEVELOPMENT BUT DIFFERENCES IN
TIMING AND DEGREE OF DEVELOPMENT CONTINUE. PWATS WILL BE AROUND
1.5 INCHES AND WILL NOT TAKE MUCH TO GET CONVECTION GOING. BEST
CHANCES WILL BE CENTRAL AND EAST FROM MID MORNING INTO AFTERNOON.
MODELS SHOWING MUCAPES OF 1500-2000 J/KG BUT SHEAR REMAINS WEAK
WITH 15-20 KNOTS COINCIDENT WITH THESE MAX CAPE VALUES. MORNING
CLOUD COVER WILL ALSO PLAY A ROLE AS USUAL SO OPTED TO KEEP POPS
IN HIGH CHANCE CATEGORY WITH SCATTERED COVERAGE MOST LIKELY.
LOCALLY HEAVY RAINFALL AGAIN POSSIBLE BUT MORE LOCALIZED NATURE
EXPECTED.

&&

.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 320 PM EDT MON JUN 29 2015

AMPLIFIED UPPER AIR PATTERN WITH MEAN TROUGH AXIS IN PLACE ACROSS
THE EASTERN US THROUGH MID-LATE WEEK WILL WEAKEN EAST BY THIS
WEEKEND/EARLY NEXT WEEK. THE RESULT WILL BE A CONTINUATION OF
UNSEASONABLY COOL TEMPERATURES WARMING CLOSER TO NORMAL TOWARD THE
END OF THE PERIOD. PRECIP CHANCES WILL DEPEND ON INDIVIDUAL
TIMING/TRACK OF SMALLER SCALE SHORTWAVES EMBEDDED IN WNW FLOW
ALOFT. FIRST FEATURE OF INTEREST LIKELY CLIPS THE LOCAL AREA ON
WEDNESDAY. ASSOCIATED WEAK FORCING ALONG ATTENDANT SFC TROUGH AND
STEEPENING LAPSE RATES WITHIN THE SFC-750 MB LAYER SUGGEST
ISOLATED CONVECTION POSSIBLE ACROSS EAST-SOUTHEAST ZONES WEDNESDAY
AFTN/EVE...WITH DEEPER MOISTURE SHUNTED WELL EAST LIMITING
COVERAGE/INTENSITY.

THE LAST SEVERAL MODEL CYCLES HAVE CONTINUED THE TREND OF FORCING
STRENGTHENING FRONTAL BOUNDARY AND BETTER RAINFALL CHANCES SOUTH
OF THE AREA WEDNESDAY NIGHT THROUGH THURSDAY NIGHT AS AREA OF
ANTI- CYCLONIC FLOW DROPS SE INTO THE GREAT LAKES REGION. AS A
RESULT LOWERED POPS WITHIN STABLE LOW LEVEL EASTERLY FLOW DURING
THESE PERIODS. RETAINED LOW-MID CHANCE POPS FOR SHOWERS/THUNDER
FRIDAY INTO THE WEEKEND AS FRONTAL BOUNDARY TRIES TO RETURN NORTH
AND SEVERAL CONVECTIVELY AIDED IMPULSES DROP THROUGH ON NORTHEAST
FRINGE OF A BUILDING PLAINS RIDGE.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 122 AM EDT TUE JUN 30 2015

STRATUS/FOG HAS BEEN TRYING TO TAKE SHAPE AT BOTH SITES. MVFR
CONDITIONS NOW IN PLACE AT KFWA WITH TRENDS HEADING THAT WAY FOR
KSBN. UPSTREAM SHOWERS/STORMS MAY DISSIPATE BEFORE REACHING EITHER
SITE. HOWEVER...WITH PROXIMITY OF UPPER LEVEL SUPPORT THE
REMAINDER OF THE NIGHT OPTED TO MOVE UP TIMING FOR VCSH. NOT
CONVINCED COVERAGE WILL END UP ENOUGH TO WARRANT MORE THAN THE
VCSH FOR THE TIME BEING. IMPROVING CONDITIONS SHOULD ARRIVE THIS
EVENING AS WAVE DEPARTS THE AREA.

&&

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

$$

UPDATE...FISHER
SYNOPSIS...MURPHY
SHORT TERM...LASHLEY
LONG TERM...STEINWEDEL
AVIATION...FISHER


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