Area Forecast Discussion
Issued by NWS Northern Indiana

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000
FXUS63 KIWX 051938
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
338 PM EDT SUN JUL 5 2015

.SYNOPSIS...
ISSUED AT 207 PM EDT SUN JUL 5 2015

DRY CONDITIONS WILL CONTINUE THROUGH MONDAY WITH HIGH PRESSURE
OVERHEAD. SKIES WILL BE MOSTLY SUNNY...THOUGH HIGH CLOUDS FROM A
SYSTEM TO THE SOUTHEAST WILL REMAIN OVER THE EASTERN FORECAST AREA
THROUGH TONIGHT. SMOKE FROM WILDFIRES IN CANADA MAY MAKE IT HAZY
AS WELL. HIGHS WILL BE IN THE MID 80S TODAY...AND RISE INTO THE
UPPER 80S MONDAY. LOWS TONIGHT WILL BE IN THE 60S.

&&

.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 338 PM EDT SUN JUL 5 2015

ONE MORE QUIET SHORT TERM PERIOD BEFORE MID/UPPER LEVEL TROUGH
APPROACHES MONDAY NIGHT. SPLIT FLOW REMAINS IN PLACE ACROSS THE
SOUTHERN GREAT LAKES AT PRESS TIME...BETWEEN RIDGING TO OUR
NORTHEAST AND CLOSED LOW TO OUR SOUTH. THIS LOW WILL CONTINUE TO
DRIFT NORTHEAST AS IT IS REABSORBED INTO THE MEAN WESTERLIES BUT
WILL BRING LITTLE MORE THAN SOME ENHANCED UPPER LEVEL CLOUDS TO OUR
AREA. MAINLY CLEAR SKIES EXPECTED OVERNIGHT AND WITH VERY LIGHT
SOUTHERLY GRADIENT SHOULD STILL SEE SOME DECENT RADIATIONAL COOLING.
SUBTLE MOISTURE ADVECTION WILL SEND DEWPOINTS BACK INTO THE LOW TO
MID 60S THOUGH AND THIS WILL SERVE AS A FLOOR ON OVERNIGHT LOWS.
INHERITED FORECAST GENERALLY IN LINE WITH LATEST GUIDANCE AND ONLY
MINOR CHANGES MADE. SOME CONCERN FOR PATCHY FOG/BR AGAIN AROUND
SUNRISE. CROSS-OVER TEMPS WILL BE DIFFICULT TO REACH BUT PREVIOUSLY
MENTIONED WEAK MOISTURE ADVECTION COULD STILL SUPPORT SOME PATCHY
RADIATIONAL FOG. NAM NEAR SURFACE MOISTURE PROFILES AND MET GUIDANCE
ARE SUPPORTIVE...AND PERSISTENCE CERTAINLY ARGUES FOR AT LEAST SOME
SHALLOW GROUND FOG...BUT CONFIDENCE IN COVERAGE/SEVERITY IS NOT HIGH
ENOUGH FOR INCLUSION IN THE FORECAST AT THIS TIME. TOMORROW LOOKS
LIKE A CLASSIC OVER-ACHIEVING DAY FOR MAX TEMPS. STRONG SOUTHWEST
FLOW/WAA WILL DEVELOP AHEAD OF APPROACHING COLD FRONT. MEANWHILE
EXPECT MOSTLY SUNNY/PARTLY CLOUDY SKIES AND STRONG JULY SUN WILL
LEAD TO RELATIVELY DEEP MIXING HEIGHTS OF NEARLY 800MB. CONTINUED TO
LEAN TOWARD WARMER MOS GUIDANCE WITH UPPER 80S AND WOULDNT BE
SURPRISED AT ALL IF A FEW PLACES TOUCH THE 90 DEGREE MARK.

&&

.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 338 PM EDT SUN JUL 5 2015

FOCUS TO BEGIN THE LONG TERM WILL BE ON EVOLUTION OF UPPER LEVEL
TROUGH SKIRTING ACROSS NORTHERN TIER OF CONUS/SOUTHERN
CANADA...AND ASSOCIATED COLD FRONTAL BOUNDARY. PREFRONTAL LOW
LEVEL MOISTURE TRANSPORT TO OVERSPREAD THE AREA LATE MONDAY NIGHT
INTO TUESDAY MORNING. SOME LOW END POTENTIAL MAY EXIST FOR
ISOLATED SHOWERS IN ASSOCIATION WITH PREFRONTAL TROUGH MONDAY
EVENING...BUT WOULD EXPECT ANY SHOWER/STORM CHANCES MONDAY EVENING
WILL BE CONFINED TO THE FAR NORTHWEST WITH RICHER LOW LEVEL
MOISTURE HELPING TO OVERCOME SOME WEAK CAPPING ISSUES.

STRONGEST FORCING WITH NORTHERN PLAINS/SOUTH CENTRAL CANADIAN UPPER
TROUGH WILL REMAIN WELL NORTH OF THE AREA INTO TUESDAY...WITH UPPER
WAVE GRADUALLY DAMPENING THROUGH TIME ACROSS SOUTHEAST ONTARIO.
LOCAL AREA SHOULD BECOME BETTER POSITIONED IN BROAD RIGHT ENTRANCE
REGION OF AN ASSOCIATED UPPER JET STREAK...WHICH COMBINED WITH
FRONTAL CONVERGENCE SHOULD SUPPORT SHOWER/STORMS OVERSPREADING THE
AREA FROM WEST TO EAST LATE MONDAY NIGHT INTO TUESDAY. STEEPEST MID
LEVEL LAPSE RATES WILL BE WELL OUT AHEAD THE FRONT IN DRIER LOW
LEVEL AIR MASS MONDAY AFTERNOON. IN ADDITION...DIURNAL TIMING LOOKS
TO BE RATHER UNFAVORABLE WITH CONTAMINATING RESIDUAL CLOUD COVER
EXPECTED DURING THE DAY TUESDAY. MORE ROBUST SHEAR PROFILES SHOULD
ALSO BE WELL INTO THE POST-FRONTAL ENVIRONMENT...AND GIVEN ABOVE
FACTORS SEVERE THREAT LOOKS TO BE QUITE MINIMAL AT THIS TIME...WITH
THE BEST CHANCE OF AN ISOLATED STRONG TO SEVERE STORM ACROSS THE
SOUTHEAST TUESDAY AFTERNOON. GREATER CONCERN WILL LIKELY BE FOR SOME
LOCALIZED HEAVIER DOWNPOURS GIVEN ABUNDANT PREFRONTAL LOW LEVEL
MOISTURE...DEEP WARM CLOUD DEPTHS...AND A FAIRLY STRONG 30-40 SWRLY
LOW LEVEL JET AIDING IN SOME UPWIND DEVELOPMENT ALONG AND IN ADVANCE
OF THE FRONT.

PRECIP CHANCES TO DIMINISH FROM NORTHWEST TO SOUTHEAST TUESDAY
AFTERNOON-TUESDAY EVENING WITH FROPA. LOW AMPLITUDE NATURE OF
MID/UPPER LEVEL FLOW STILL APPEARS TO SUPPORT PERIODIC CHANCES OF
SHOWERS AND THUNDERSTORMS IN THE WEDNESDAY NIGHT-FRIDAY TIMEFRAME AS
LOW LEVEL THETAE GRADIENT ADVECTS BACK NORTHWARD...PARTICULARLY LATE
WEDNESDAY NIGHT-THURSDAY. OPTED TO MAINTAIN BROADBRUSH LOW CHANCE
TSRA POPS THROUGH THE WEEKEND AS CUT OFF UPPER LEVEL PV ANOMALY
ACROSS SOUTHWEST CONUS EVENTUALLY BEGINS TO DAMPEN CENTRAL CONUS MID
LEVEL RIDGING. MODERATING TEMPERATURES ALSO EXPECTED FOR LATE WEEK
WITH HIGHS BACK INTO THE LOWER TO MID 80S FOR NEXT WEEKEND.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 122 PM EDT SUN JUL 5 2015

PERSISTENT HIGH PRESSURE AT THE SURFACE AND ALOFT WILL MAINTAIN
PRIMARILY VFR CONDITIONS THROUGH THE PERIOD. THE ONLY POSSIBLE
EXCEPTION WILL BE AROUND SUNRISE TOMORROW AS LIGHT WINDS AND
MAINLY CLEAR SKIES SET THE STAGE FOR SOME RADIATIONAL FOG.
GRADIENT IS A LITTLE STRONGER THAN LAST NIGHT BUT SOME WEAK
MOISTURE ADVECTION ALSO NOTED. NAM FORECAST SOUNDINGS AND MOS
GUIDANCE SUGGEST SOME MVFR BR AND CONDITIONS OVER THE PAST TWO
NIGHTS SUPPORT THAT ARGUMENT. NOT EXPECTING DENSE FOG BUT SOME VIS
RESTRICTION CERTAINLY POSSIBLE AND HAVE INTRODUCED JUST A HIGH
END MVFR MENTION FOR NOW.

&&

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

$$

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


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