Area Forecast Discussion
Issued by NWS Northern Indiana

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000
FXUS63 KIWX 301749
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
149 PM EDT SAT APR 30 2016

.SYNOPSIS...
ISSUED AT 144 PM EDT SAT APR 30 2016

RAIN WILL CONTINUE OVER THE AREA INTO THE OVERNIGHT HOURS WITH
MOST AREAS RECEIVING BETWEEN ONE HALF TO ONE INCH OF RAINFALL. LOWS
SUNDAY MORNING WILL RANGE FROM THE MIDDLE 40S IN SOUTH CENTRAL
MICHIGAN TO NEAR 50 INTO CENTRAL INDIANA. HIGHS ON SUNDAY WILL BE
IN THE MID 50S TO MID 60S WITH STILL A CHANCE OF SHOWERS AND
POSSIBLE THUNDERSTORMS.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 354 AM EDT SAT APR 30 2016

DRY CONDITIONS SHOULD PERSIST FOR MOST AREAS THROUGH 12Z THIS
MORNING AS SFC WARM FRONT AND INCREASED THETA E SURGE REMAINS FROM
EAST OF KANSAS CITY TO NORTH OF ST LOUIS INTO NW KENTUCKY. WHILE
NORTHWARD PROGRESS IS BEING MADE IT IS VERY SLOW AS SUGGESTED TO
BY MAJORITY OF MODELS. SOME LIGHTER PRECIP WAS NOTED FROM SE IOWA
INTO CENTRAL IL BUT LITTLE MORE THAN SPRINKLES NOTED. SUSPECT THIS
AREA WILL WEAKEN SOME AS IT PROGRESSES NORTH AND ENCOUNTERS A
SOMEWHAT DRIER NE FLOW BUT COULD BRING SOME SPRINKLES OR BARELY
MEASURABLE PRECIP INTO FAR SW AREAS PRIOR TO 12Z. BASED ON THIS
HAVE CONTINUED WITH A SOMEWHAT SLOWER TREND TO ARRIVAL OF RAIN AS
ISENTROPIC LIFT BEGINS AFTER 12Z SAT AND PEAKS 18Z TO 00Z SUN WITH
40 TO 50 KT CROSS FLOW OVER 295 TO 300K PRESSURE SURFACES YIELDING
WHAT SHOULD TURN OUT TO BE A LARGE AREA OF STEADY RAIN. CAN`T RULE
OUT SOME THUNDER EMBEDDED WITHIN THE AREA...BUT GREATEST CHANCE
FOR CONVECTION WOULD OCCUR ON THE SOUTHERN FLANK OF THE AREA
CLOSER TO THE WARM FRONT AND LIMITED INSTABILITY. HAVE LEFT SLGT
CHC THUNDER MENTION LATE AM INTO EARLY EVE GENERALLY SOUTH OF US
30 WITH NO SIG CHANGES FOR THE AREA ON THE NEW DAY 1 SPC OUTLOOK.
MOST LOCATIONS SHOULD SEE ONE HALF TO THREE QUARTERS OF AN INCH OF
RAIN WITH POTENTIAL FOR SOME LOCATIONS TO SEE AN INCH OR SO.

RAINFALL COULD BEGIN TO WIND DOWN TOWARDS 00Z SUN IN SW AREAS BUT
HAVE KEPT CAT POPS INTO EARLY EVE BEFORE TAPERING OFF TO CHC
SHOWERS/STORMS INTO THE OVERNIGHT HOURS. NO MAJOR CHANGES IN
TEMPERATURES AS WARM FRONT WILL GENERALLY REMAIN NEAR/SOUTH OF
US-24 CORRIDOR BY 12Z SUN.

&&

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 354 AM EDT SAT APR 30 2016

A LULL IN GREATER RAIN COVERAGE SHOULD CONTINUE INTO EARLY SUNDAY AS
LEAD SHORT WAVE SHIFTS OFF TO THE NORTHEAST AND LOW LEVEL FLOW
BECOMES MORE VEERED. RAIN SHOWER COVERAGE SHOULD INCREASE ONCE AGAIN
BY SUNDAY AFTERNOON AS DAMPENING/SHEARING UPPER LEVEL PV ANOMALY
APPROACHES THE SOUTHERN GREAT LAKES/OHIO VALLEY. IT STILL APPEARS AS
THOUGH BEST CHANNELED DCVA SHOULD AFFECT ESPECIALLY SOUTHEAST HALF
OF FORECAST AREA SUNDAY AFTERNOON. OF LOW CONFIDENCE FOR SUNDAY IS
CONVECTIVE POTENTIAL AND EXTENT OF THUNDER. SUBTLE DIFFERENCES IN
LOW LEVEL FEATURES WILL HAVE A LARGE IMPACT ON THERMODYNAMIC
PROFILES SUNDAY WITH NAM/GFS EXHIBITING QUITE A LARGE DIFFERENCE IN
AFTERNOON INSTABILITY. 00Z NAM REMAINS A FAST/STRONG OUTLIER IN
TERMS OF SFC REFLECTION THROUGH THE AREA EARLY SUNDAY MORNING IN
COMPARISON TO BULK OF OTHER GUIDANCE. HAVE SOME CONCERN THAT NAM MAY
BE TOO INFLUENCED BY PRIOR 12-24 HOUR UPSTREAM CONVECTION AND
PERHAPS A LITTLE CONTAMINATED WITH SFC/LOW LEVEL EVOLUTION EARLY
SUNDAY. WITH PREFERENCE TO SLOWER EC/GFS...LOW LEVEL THERMAL
RIDGING/INSTABILITY AXIS WOULD EXHIBIT GREATER NORTHWARD ADVANCEMENT
ACROSS CENTRAL/NORTHERN PORTIONS OF THE FORECAST AREA SUNDAY
AFTERNOON. WHILE MID LEVEL LAPSE RATES SHOULD STEEPEN SUNDAY
AFTERNOON DUE TO DIFFERENTIAL ADVECTION...DEPTH OF MOISTURE AND
ABILITY TO REALIZE THESE STEEPER MID LEVEL LAPSE RATES REMAINS AN
ITEM OF LOWER CONFIDENCE. DID EXPAND ISOLD THUNDER MENTION ACROSS
FAR NORTHERN INDIANA. CANNOT COMPLETELY RULE OUT POTENTIAL OF FEW
STRONGER STORMS ACROSS SOUTHEAST HALF OF THE AREA SUNDAY AFTERNOON
GIVEN POTENTIAL WEAK-MODERATE INSTABILITY AND INCREASING SHEAR
PROFILES ASSOCIATED WITH UPPER SPEED MAX NOSING ACROSS THE OHIO
RIVER VALLEY PLACING THE AREA IN FAVORABLE LEFT EXIT REGION...BUT
AGAIN CONFIDENCE IS ON THE LOW SIDE DUE TO UNCERTAINTY IN REGARDS TO
WHERE SHARPER BAROCLINIC ZONE/LOW LEVEL MOISTURE GRADIENT SETS UP.

FOR SUNDAY NIGHT...POCKET OF STEEPER MID LEVEL LAPSE RATES SHOULD BE
EXITING THE EAST WITH UPPER PV ANOMALY SLOW TO DEPART. THIS SHOULD
ALLOW FOR SCATTERED SHOWERS TO PERSIST INTO SUNDAY EVENING BEFORE
DIMINISHING OVERNIGHT. CLOUDS WILL DECREASE ON EARLY MONDAY WITH
JUST SOME FAIR WEATHER CU DEVELOPING IN THE AFTERNOON. HIGHS ON
MONDAY SHOULD REACH INTO THE UPPER 50S/LOWER 60S...BUT AIR MASS WILL
BE CONSIDERABLY DRIER.

GENERAL THEME OF THE REMAINDER OF THE LONG TERM REMAINS UNCHANGED
WITH UPPER VORT EXPECTED TO DROP ACROSS GREAT LAKES REGION
WEDNESDAY/THURSDAY WITH NEXT FROPA FOR WEDNESDAY. LOW LEVEL W-NW
FLOW WILL LIMIT SIGNIFICANT MOISTURE RETURN AHEAD OF THIS FRONT BUT
WILL KEEP CHANCE POPS IN PLACE WITH BAND OF SHOWERS LIKELY TO
ACCOMPANY THIS FRONTAL BOUNDARY. UPON COLLABORATION WITH SURROUNDING
WFOS DID GO A LITTLE COOLER FOR THE THURSDAY-FRIDAY PERIOD AS
CONFIDENCE IN BROAD LOW LEVEL THERMAL TROUGHING IS BEGINNING TO
INCREASE FOR THIS PERIOD WHICH SHOULD KEEP TEMPS BELOW SEASONABLE
NORMS FOR END OF THE WEEK.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1254 PM EDT SAT APR 30 2016

YET ANOTHER SLOW UPPER LEVEL PLAINS SYSTEM TO LIFT/FILL INTO THE
SOUTHWEST UPPER GREAT LAKES THROUGH THE PERIOD. PERSISTENCE OF
COLD SIDE OF OCCLUDING FRONTAL SYSTEM TO WARRANT DETERIORATING
FLIGHT CONDS ESPCLY WITH RESPECT TO CIGS THROUGH THE PERIOD WITH
IFR/LIFR CIGS LIKELY FOR MAJORITY OF OVERNIGHT PERIOD...WITH
GRADUALLY LIFTING CIGS INTO MIDDAY SUNDAY WITH INCREASED MIXING
DEPTH.

&&

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

$$

SYNOPSIS...MURPHY
SHORT TERM...FISHER
LONG TERM...MARSILI
AVIATION...MURPHY


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