000
FXUS63 KIWX 200531
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
131 AM EDT SUN JUL 20 2014

.SYNOPSIS...
ISSUED AT 326 PM EDT SAT JUL 19 2014

AN UPPER LEVEL LOW PRESSURE SYSTEM WILL CONTINUE TO MOVE OFF TO THE
EAST ALLOWING FOR HIGH PRESSURE TO BUILD IN OVER THE AREA TONIGHT.
DRY WEATHER IS EXPECTED TONIGHT INTO THE BEGINNING OF NEXT WEEK WITH
A WARMING TREND IN TEMPERATURES. LOWS TONIGHT WILL RANGE FROM THE
MID 50S TO LOW 60S WITH HIGHS ON SUNDAY IN THE LOW 80S.

&&

.UPDATE...
ISSUED AT 749 PM EDT SAT JUL 19 2014

ZONES UPDATED TO REMOVE 1ST PERIOD MENTION OF SHOWERS IN FAR SE AS
WELL AS CHANGES IN SKY COVER.

AREA OF SHOWERS OVER NW OHIO...WHICH WAS RESPONSIBLE FOR A FEW
FUNNEL CLOUD REPORTS HAVE QUICKLY DISSIPATED WITH WAKE TROUGH AXIS
STILL IN PLACE IN THESE AREAS. CLOUD COVER WAS QUICKLY
DISSIPATING...EVEN IN FAR SE AREAS. HAVE THEREFORE LOWERED SKY
COVER QUICKER THAN PREVIOUS GRIDS. OVERNIGHT LOWS WERE LEFT ALONE
FOR NOW...HOWEVER WITH QUICKER LOSS OF CLOUDS MAY NEED TO LOWER A
FEW DEGREES. WILL MONITOR OVER NEXT FEW HOURS.

&&

.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 326 PM EDT SAT JUL 19 2014

LEFTOVER WEAK LOW LEVEL TROUGH/MOISTURE AXIS AND SOME MARGINAL
DIURNAL DESTABILIZATION MAY BE ENOUGH TO GENERATE A FEW LIGHT
SHOWERS/SPRINKLES THIS AFTERNOON EAST OF INTERSTATE 69. MOST
LOCATIONS WILL REMAIN DRY GIVEN OVERSPREAD OF LARGE SCALE
SUBSIDENCE IN WAKE OF UPPER LEVEL SHORTWAVE NOW EXITING TOWARD
LAKE HURON. BKN-OVC STRATOCUMULUS DECK UNDER STRENGTHENING
SUBSIDENCE INVERSION SHOULD THIN/SCATTER OUT EARLY THIS EVENING
(MAINLY NORTHERN/WESTERN ZONES) GIVEN LOSS OF HEATING.

GRADUAL INCREASE IN HEIGHTS IN FLATTER NW FLOW WILL PROMOTE DRY
WX/LIGHT WINDS TONIGHT INTO SUNDAY AS LOW LEVEL RIDGING BECOMES
BETTER ESTABLISHED. LIGHT/CALM WINDS, PERIOD OF CLEARING SKIES,
AND LINGERING NEAR SFC MOISTURE INVOF WASHED OUT TROUGH HINTS AT
FOG/STRATUS POTENTIAL LATER TONIGHT. INTRODUCED PATCHY FOG IN THE
GRIDS...WITH BEST CHANCES FOR IMPACTFUL FOG ACROSS NORTHEAST
INDIANA/NORTHWEST OHIO IF SKIES CLEAR FOR A TIME. TEMPS SHOULD
RECOVER NICELY INTO THE UPPER 70S/LOW 80S WITH AMPLE INSOLATION ON
SUNDAY AFTER ANY MORNING FOG/STRATUS MIXES OUT.

&&

.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 326 PM EDT SAT JUL 19 2014

INCREASING HEAT FOR EARLY NEXT WEEK...CONVECTIVE CHANCES TUESDAY
NIGHT-EARLY THURSDAY...FOLLOWED BY RETURN TO SLIGHTLY BELOW NORMAL
TEMPERATURES WILL BE THE MAIN FORECAST ISSUES FOR THE LONG TERM.

A WEAK REINFORCING SHORT WAVE TROUGH WILL MOVE ACROSS PORTIONS OF
THE OHIO VALLEY AND EASTERN GREAT LAKES SUNDAY EVENING...WHICH WILL
PAVE THE WAY FOR PERIOD OF MID/UPPER LEVEL HEIGHT RISES GOING INTO
MONDAY AND TUESDAY. THIS WILL RESULT IN EASTWARD MIGRATION OF
CENTRAL/NORTHERN PLAINS LOW LEVEL THERMAL RIDGE FOR MONDAY AND
TUESDAY. MODELS STILL DIVERGE QUITE A BIT IN TERMS OF THE
PROGRESSION AND TIMING OF CORE OF LOW LEVEL THERMAL RIDGING...WITH
WARMER GFS HAVING JUST SLIGHTLY BACKED OFF ON TIMING LOW LEVEL RIDGE
INTO LOCAL AREA MONDAY/MONDAY NIGHT WITH THE 12Z RUN. WARMEST DAY OF
THE PERIOD APPEARS TO BE SHAPING UP FOR TUESDAY WITH CORE OF LOW
LEVEL THERMAL RIDGE ACROSS THE AREA...AND MODEL CONSENSUS 850 HPA
TEMPS IN THE 19 TO 21 DEGREE CELSIUS RANGE BY TUESDAY AFTERNOON.
GOOD DEAL OF INSOLATION IS ALSO CURRENTLY EXPECTED FOR TUESDAY
AFTERNOON...AND CONFIDENCE OF 90+ AFTERNOON TEMPERATURES IS
INCREASING. OF SOMEWHAT LOWER CONFIDENCE WILL BE DEW POINT TRENDS AS
LOCAL AREA SHOULD REMAIN INFLUENCED BY AXIS OF SLIGHTLY DRIER LOW
LEVEL AIR RESULTING FROM LINGERING EFFECTS OF SEVERAL DAYS OF
SYNOPTIC SCALE SUBSIDENCE. BY TUESDAY...SOME INDICATIONS THAT MODEST
RAMP UP IN LOW LEVEL SOUTH-SOUTHEAST FLOW SHOULD BEGIN TO ADVECT
BETTER LOW LEVEL MOISTURE NORTHWESTWARD INTO THE AREA. WILL MAINTAIN
TREND UPWARD TO UPPER 60S TO AROUND 70 DEW POINTS IN GRIDS FOR
TUESDAY...ALTHOUGH IT IS POSSIBLE DEPENDING ON DEPTH OF AFTERNOON
MIXING THAT DEW POINTS COULD DROP OFF A LITTLE MORE THAN THIS.
CURRENTLY FORECASTED TEMPS/DEW POINTS WOULD SUPPORT HEAT INDICES IN
THE MID 90S FOR TUESDAY AFTERNOON.

ATTENTION FOR TUESDAY NIGHT/WEDNESDAY WILL SHIFT TO NEXT FAST MOVING
PACIFIC WAVE EMANATING FROM CUT-OFF PV ANOMALY CURRENTLY RESIDING
ACROSS THE SOUTHWEST CONUS. SLIGHTLY FASTER TREND HAS BEEN NOTED
AMONG DETERMINISTIC/ENSEMBLE SOLUTIONS OVER PAST SEVERAL
RUNS...WHICH SEEMS TO FALL INLINE WITH TRENDS MADE FROM PREVIOUS
FORECAST. STILL DIFFICULT AT THIS PERIOD TO GO MUCH MORE THAN MID TO
HIGH CHANCE POPS HOWEVER...WITH OBVIOUS LOW CONFIDENCE ON HOW
UPSTREAM CONVECTION MONDAY NIGHT-TUESDAY AFFECTS
STRENGTH/TIMING/TRACK OF SYNOPTIC WAVE. STILL EXPECTING THE LATE
TUESDAY/EARLY WEDNESDAY PERIOD TO CORRESPOND TO MOST SIGNIFICANT
MOISTURE AXIS PUSHING INTO THE AREA POOLED ALONG AND IN ADVANCE OF
SFC/LOW LEVEL BOUNDARY. TEMPERATURE FORECAST FOR WEDNESDAY OF LOWER
CONFIDENCE GIVEN POTENTIAL EFFECTS OF CLOUDS/PRECIP...WITH SOME
POTENTIAL OF WARMER THAN FORECASTED HIGHS ACROSS SOUTHEAST LOCATIONS
IF SOME BETTER INSOLATION CAN BE REALIZED. JUST SOME MINOR
ADJUSTMENTS MADE TO POPS INTO THURSDAY TO CONTINUE THE IDEA OF A
SLIGHTLY FASTER SOLUTION...BUT HAVE MAINTAINED TREND BACK TO HIGHS
IN UPPER 70S/LOWER 80S TOWARD THE END OF THE PERIOD. DID ADD A
CHANCE TSRA FOR DAY 7 WITH AT LEAST SOME CONSENSUS IN MEDIUM RANGE
MODELS OF STRONGER SOUTH CENTRAL CANADIAN UPPER VORT MAX INDUCING
DOWNSTREAM WAA OVER LOCAL AREA.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 129 AM EDT SUN JUL 20 2014

HIGH PRESSURE RIDGE OVER THE AREA EARLY THIS MORNING WILL PERSIST
THROUGH THE TAF PERIOD RESULTING IN CONTD LIGHT WINDS. PATCHY STRATO
CU REMAINS ACROSS THE AREA ATTM AND CU SHOULD DEVELOP AGAIN TODAY
BUT EXPECT PREDOMINANTLY SCT CLOUDS OVER THE NEXT 24HRS WITH JUST
BRIEF VFR CIGS. MAIN CONCERN FOR AVIATION INTERESTS IS FOR FOG EARLY
THIS MORNING. FWA HAS REACHED CROSS-OVER TEMP ALREADY AND EXPECT
BR WILL FORM SHORTLY AND CONT THROUGH THE REST OF THE NIGHT WITH IFR
CONDITIONS LIKELY AROUND DAYBREAK... WHILE MORE CLOUDS AT SBN
SHOULD LIMIT RADIATIONAL COOLING AND KEEP VSBYS FROM FALLING BELOW
MVFR.

&&

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

$$

UPDATE...CEO/FISHER
SYNOPSIS...CEO
SHORT TERM...STEINWEDEL
LONG TERM...MARSILI
AVIATION...JT


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