Area Forecast Discussion
Issued by NWS Northern Indiana

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000
FXUS63 KIWX 290537
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
137 AM EDT MON SEP 29 2014

.SYNOPSIS...
ISSUED AT 358 PM EDT SUN SEP 28 2014

HIGH PRESSURE WILL MAINTAIN DRY AND MOSTLY CLEAR CONDITIONS
THROUGH MONDAY. LOWS TONIGHT WILL BE IN THE LOW 50S WITH HIGHS
ON MONDAY IN THE UPPER 70S. THERE IS A CHANCE OF RAIN MONDAY
NIGHT AS A WEAK COLD FRONT PASSES THROUGH THE REGION.

&&

.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 358 PM EDT SUN SEP 28 2014

YET ANOTHER TRANQUIL SHORT TERM FORECAST PERIOD AS VERY DRY LOW
LEVEL RIDGE REMAINS PARKED OVER THE OHIO VALLEY. WEAKENING
MIDLEVEL CIRCULATION COULD BRING A FEW MORE HIGH BASED CLOUDS TO
THE AREA OVERNIGHT BUT EXPECTING MOSTLY CLEAR SKIES AND LIGHT
SURFACE WINDS. THIS SHOULD PROMOTE GOOD RADIATIONAL COOLING AND
EXPECT ANOTHER NIGHT WITH TEMPS GENERALLY IN THE LOW 50S. FORECAST
SOUNDINGS AND MOS GUIDANCE SUGGEST SOME PATCHY RADIATIONAL GROUND
FOG WILL BE POSSIBLE AGAIN TOMORROW MORNING. OVERALL LATEST
GUIDANCE IS LESS AGGRESSIVE WITH NEAR SURFACE MOISTURE PROFILES
AND BASED ON ISOLATED/THIN NATURE OF FOG THIS MORNING...NOT
EXPECTING ANY LARGE AREAS OF DENSE FOG TOMORROW. WILL LEAVE IN A
PATCHY FOG MENTION THOUGH...FOR THE POCKETS OF SHALLOW GROUND FOG
THAT ALMOST ALWAYS DEVELOP ON GOOD RADIATIONAL NIGHTS. A SHARP
MID/UPPER LEVEL SHORTWAVE TROUGH WILL THEN PUSH INTO THE NORTHERN
GREAT LAKES TOMORROW. THIS WAVE WILL EVENTUALLY SEND A COLD FRONT
THROUGH THE REGION BUT NO IMPACTS ARE EXPECTED PRIOR TO MONDAY
NIGHT. LITTLE IF ANY THERMAL ADVECTION SEEN AHEAD OF THIS FRONT
EITHER AND ANOTHER DAY OF TEMPS IN THE UPPER 70S TO AROUND 80F IS
EXPECTED.

&&

.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 358 PM EDT SUN SEP 28 2014

MAIN ITEMS OF CONCERN FOR THE LONG TERM WILL CONTINUE TO BE UPPER
WAVE TO TRACK ACROSS THE GREAT LAKES REGION MONDAY NIGHT/EARLY
TUESDAY...AND THEN A MORE SUBSTANTIAL UPPER LEVEL SYSTEM TO AFFECT
THE AREA THURSDAY/FRIDAY.

MODELS CONTINUE TREND TO MORE AMPLIFICATION WITH SHORT WAVE TRACKING
ACROSS THE GREAT LAKES REGION MONDAY NIGHT INTO TUESDAY...MORE
INLINE WITH STRONGER EC/GEM TRENDS AS OF LATE. STRONGEST DPVA STILL
APPEARS TO BE CONFINED NORTH OF LOCAL AREA...ALTHOUGH MORE AMPLIFIED
SOLUTION SHOULD RESULT IN ZONE OF WEAK LOW LEVEL MOISTURE POOLING
AND WEAK POST-SFC FRONTAL LOW LEVEL FRONTOGENESIS TO AFFECT THE
SOUTHERN GREAT LAKES. HAVE LARGELY KEPT THE IDEA OF THE PREVIOUS
FORECAST WITH HIGHEST POPS IN THE 06Z-12Z TIMEFRAME MONDAY NIGHT.
TRACK OF AFOREMENTIONED VORT MAX EAST/SOUTHEAST INTO THE EASTERN
GREAT LAKES ON TUESDAY COULD STILL PROVIDE ENOUGH FORCING FOR
ISOLD/SCT LIGHT RAIN RAIN SHOWERS INTO TUESDAY MORNING ACROSS THE
FAR EAST. OTHER QUESTION FOR TUESDAY WILL BE EXTENT OF POST-FRONTAL
STRATOCU WITH THE POSSIBILITY OF LINGERING LOW LEVEL MOISTURE
TRAPPED BENEATH THE FRONTAL INVERSION. HAVE CONTINUED TREND OF
PREVIOUS FORECAST IN STEERING TO THE MORE AMPLIFIED SOLUTION WITH
LOWER TEMPS TUESDAY AND MORE CLOUD COVER. HAVE ALSO MADE SLIGHT
DOWNWARD ADJUSTMENT TO TEMPS ON WEDNESDAY WITH MIXING HEIGHTS
EXPECTED TO REMAIN RELATIVELY SHALLOW AS WEAK RIDGE OF HIGH PRESSURE
SETTLES ACROSS THE WESTERN GREAT LAKES.

FOR WEDNESDAY NIGHT...LEAD UPPER LEVEL SHORT WAVE WILL LIFT INTO
WESTERN ONTARIO...WITH NEXT FAST MOVING EASTERN PACIFIC WAVE
PROGRESSING THROUGH WESTERN CONUS LONGWAVE TROUGH INTO THE CENTRAL
PLAINS BY THURSDAY MORNING. DPROG/DT ANALYSIS SUGGESTS A FASTER
EVOLUTION FROM PREVIOUS INDICATIONS IN BULK OF DETERMINISTIC
SOLUTIONS...WITH MORE RAPID ONSET OF MORE SIGNIFICANT LOW LEVEL
THETA ADVECTION LATE WEDNESDAY NIGHT INTO THURSDAY. ONLY TWEAK TO
THIS FORECAST WAS TO MOVE UP TIMING OF LIKELY POPS JUST A BIT...AND
TO INDICATE A BIT MORE IN THE WAY OF THUNDER GIVEN WHAT SHOULD BE
IMPRESSIVE UPPER DYNAMICS AND AT LEAST THE POSSIBILITY OF A NARROW
WEAK TO MODERATE INSTABILITY AXIS LIFTING INTO PORTIONS OF THE AREA
THURSDAY/THURSDAY NIGHT.

UNSETTLED PATTERN TO CONTINUE FRIDAY AND SATURDAY AS REINFORCING
UPPER LEVEL SHORT WAVE DIGS ACROSS THE GREAT LAKES REGION. KEPT
HIGHEST CHANCE RAIN SHOWER POPS DOWNWIND OF LAKE MICHIGAN WITH LAKE
ENHANCEMENT/EFFECT POSSIBLE DURING THIS PERIOD. MUCH COOLER
TEMPERATURES CAN BE EXPECTED FOR NEXT WEEKEND WITH HIGHS FROM THE
UPPER 50S TO LOWER 60S.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 128 AM EDT MON SEP 29 2014

WK HIGH PRESSURE RIDGE OVER THE AREA EARLY THIS MORNING RESULTING
IN NEARLY CALM WINDS. A WK SHRTWV WAS MOVG THROUGH NE INDIANA
CAUSING SOME CIRRUS. THIS SHOULD PUSH EAST OF THE AREA OVERNIGHT.
STRONG RADIATIONAL COOLING EXPECTED TO CAUSE BR TO FORM AT THE
TERMINALS WITH MVFR CONDITIONS BY DAYBREAK. VFR CONDITIONS SHOULD
RETURN BY LATE MORNING. A STRONGER SHRTWV AND BACKDOOR CDFNT WILL
MOVE SOUTH ACROSS THE GRTLKS TONIGHT CAUSING WINDS TO SHIFT FROM
W-NW TO NORTH. AREA OF LOW CIGS FOLLOWING THIS FRONT SHOULD
OVERSPREAD NRN INDIANA TONIGHT.

&&

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

$$

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


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