Area Forecast Discussion
Issued by NWS Northern Indiana

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000
FXUS63 KIWX 280519
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
119 AM EDT SUN SEP 28 2014

.SYNOPSIS...
ISSUED AT 705 PM EDT SAT SEP 27 2014

HIGH PRESSURE WILL CONTINUE TO PROVIDE CALM AND DRY CONDITIONS
INTO THE UPCOMING WEEK. LOW TEMPERATURES TONIGHT WILL DROP INTO
THE LOWER AND MIDDLE 50S WITH LIGHT OR CALM WINDS. THIS WILL ALSO
ALLOW FOG TO FORM ONCE AGAIN AND IT WILL BE DENSE IN SPOTS. ONCE
THE FOG BURNS OFF AFTER SUNRISE ON SUNDAY...TEMPERATURES WILL WARM
INTO THE UPPER 70S AND LOWER 80S.

&&

.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 332 PM EDT SAT SEP 27 2014

BEHEMOTH EASTERN CONUS UPPER RIDGE WILL BEGIN TO BREAK DOWN AND
SHIFT EASTWARD DURING THIS PERIOD...ALLOWING CLOSED LOW OVER IOWA
TO OPEN UP AND DRIFT EASTWARD AS WELL. EXCEPTIONALLY DRY AND
STABLE LOW LEVEL ANTICYCLONIC BUBBLE WILL MAINTAIN A LARGE
INFLUENCE OVER THE REGION THOUGH...AND LITTLE TO NO SENSIBLE
WEATHER IMPACTS ARE EXPECTED. THE ONLY EVIDENCE OF APPROACHING
WAVE WILL BE A CONTINUATION AND EXPANSION OF UPPER LEVEL CLOUDS
THROUGH TOMORROW MORNING. THESE CLOUDS MAY HINDER RADIATIONAL
COOLING SOMEWHAT AND HAVE STUCK CLOSE TO INHERITED MIN TEMPS IN
THE LOW TO MID 50S. CURRENT SURFACE OBS INDICATE MOST DEWPOINTS
HOLDING IN THE MID 50S DURING PEAK BOUNDARY LAYER MIXING SO SOME
PATCHY RADIATIONAL FOG WILL BE POSSIBLE OVERNIGHT YET AGAIN GIVEN
CALM SURFACE WINDS. NOT EXPECTING WIDESPREAD DENSE FOG WITH
MARGINAL SURFACE DEWPOINTS BUT ISOLATED AREAS OF DENSE FOG WILL BE
POSSIBLE...SIMILAR TO THE PAST FEW DAYS. EXPECT ANOTHER MOSTLY
SUNNY DAY TOMORROW WITH JUST MORE PASSING HIGH BASED CLOUDS AND
PERHAPS A FEW ISOLATED CU. TEMPS WILL BE A NEAR CARBON COPY OF
TODAY WITH NO CHANGE IN THE CHARACTERISTICS OF THE LOW LEVEL
AIRMASS CURRENTLY IN PLACE. PERSISTENCE FORECAST OF AROUND 80F
SEEMS APPROPRIATE.

&&

.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 332 PM EDT SAT SEP 27 2014

CUTOFF UPPER LOW ACROSS THE CORN BELT WILL DRIFT ACROSS THE WESTERN
GREAT LAKES TO BEGIN THE PERIOD SUNDAY NIGHT...WHICH WILL BE
FOLLOWED BY SHORT WAVE UPPER RIDGING FOR MONDAY. LOW LEVEL MOISTURE
WILL BE LACKING WITH PASSAGE OF THIS UPPER TROUGH SUNDAY NIGHT WITH
JUST SOME SCT HIGH LEVEL CLOUDS EXPECTED. DRY CONDITIONS TO PERSIST
THROUGH MONDAY WITH SHORT WAVE RIDGE IN PLACE. A MORE PROGRESSIVE
NORTHERN STREAM TROUGH WILL THEN APPROACH THE GREAT LAKES/ONTARIO BY
MONDAY NIGHT EARLY TUESDAY. THIS VORT MAX WILL BECOME INCREASINGLY
SHEARED IN NATURE AS IT APPROACHES THE GREAT LAKES. BETTER FORCING
DOES APPEAR TO SET UP NORTH OF THE LOCAL AREA...HOWEVER A BRIEF
PERIOD OF ENHANCED DPVA IS POSSIBLE ACROSS FAR NORTHEAST SECTIONS OF
THE AREA LATE MONDAY NIGHT. PRECIP PROSPECTS STILL LOOK LOW WITH
THIS TROUGH GIVEN BETTER LOW LEVEL MOISTURE CIRCUMNAVIGATING THE
AREA INTO THE WESTERN/CENTRAL GREAT LAKES. HAVE ADDED JUST SLIGHT
CHANCE RAIN SHOWER POPS ACROSS THE FAR NORTHEAST. SHEARED NATURE OF
UPPER TROUGH AND BUILDING HEIGHTS AGAIN FOR TUESDAY SUGGEST LOW
LEVEL BAROCLINIC ZONE MAY NOT MAKE SUBSTANTIAL SOUTHWARD PROGRESS
BEHIND THIS WAVE...AND THUS TUESDAYS TEMPS MAY NOT BE SIGNIFICANTLY
LOWER THAN THAT OF MONDAY...WITH POSSIBLE EXCEPTION IN VICINITY OF
LAKE MICHIGAN WHERE ONSHORE FLOW IS LIKELY. HAVE MAINTAINED LOW TO
MID 70S HIGHS TUESDAY...ALTHOUGH MAY BE ABLE TO DO SOME SLIGHT
UPWARD ADJUSTMENT TO MAX TEMPS IN UPCOMING FORECAST CYCLES FOR
TUESDAY AFTERNOON IF CURRENT TRENDS HOLD.

QUIET CONDITIONS FOR TUESDAY NIGHT THROUGH MOST OF THURSDAY...WITH
ATTENTION THEN SHIFTING TO INCREASING PRECIP CHANCES LATE THURSDAY
INTO FRIDAY. MEDIUM RANGE MODELS ARE IN GOOD AGREEMENT IN TAKING
AMPLIFIED LEAD SHORT WAVE NORTHWARD INTO SOUTHERN CANADA WEDNESDAY
NIGHT RESULTING IN FAIRLY SLOW EASTWARD FRONTAL EVOLUTION WEDNESDAY
NIGHT-FRIDAY. PREVIOUS FORECAST SEEMS TO CAPTURE OVERALL TRENDS IN
SOLUTIONS...AND WILL MAINTAIN HIGHEST POPS LATE THURSDAY NIGHT INTO
FRIDAY WITH APPROACH OF MAIN UPPER LEVEL TROUGH AND FRONTAL
BOUNDARY. THUNDER PROSPECTS DO NOT SEEM ALL THAT HIGH AT THIS POINT
WITH MARGINAL INSTABILITY...BUT GIVEN WHAT COULD BE FAIRLY
IMPRESSIVE UPPER DYNAMICS...SOME ISOLD THUNDER POTENTIAL IS POSSIBLE
ALONG WHAT WOULD BE NARROW...WEAK INSTABILITY AXIS. TRANSITION TO
MUCH COOLER TEMPS STILL APPEARS REASONABLE TOWARD THE END OF THE
PERIOD IN THE WAKE OF THIS SYSTEM.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 115 AM EDT SUN SEP 28 2014

LIGHT LOW LEVEL WIND FLOW WITH JUST PATCHY CIRRUS SHOULD ALLOW
RADIATIONAL COOLING BR/FG WITH MVFR/IFR CONDITIONS TO DEVELOP EARLY THIS
MORNING. VSBYS WILL IMPROVE BY LATE MORNING. WK SHRTWV MOVG ACROSS
THE AREA TODAY SHOULD SUSTAIN PATCHY CIRRUS WHILE WK SFC RIDGE
OVER THE AREA SUPPORTS LIGHT MAINLY N-NW WIND FLOW.

&&

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

$$

SYNOPSIS...LASHLEY
SHORT TERM...AGD
LONG TERM...MARSILI
AVIATION...JT


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