Area Forecast Discussion
Issued by NWS Northern Indiana

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FXUS63 KIWX 200524
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
124 AM EDT MON APR 20 2015

.SYNOPSIS...
ISSUED AT 802 PM EDT SUN APR 19 2015

LOW PRESSURE WILL MOVE NORTH THROUGH THE REGION AND INTO NORTHERN
LOWER MICHIGAN BY MIDDAY MONDAY. RAIN WILL BECOME MORE ISOLATED IN
NATURE OVERNIGHT...WITH ANOTHER ROUND OF SHOWERS MONDAY MORNING.
OVERNIGHT LOWS WILL BE IN THE UPPER 40S TO LOWER 50S. HIGHS ON
MONDAY WILL BE IN THE UPPER 50S TO LOWER 60S.

&&

.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 351 PM EDT SUN APR 19 2015

REGIONAL RADAR MOSAIC SHOWS LARGE AREA OF RAIN ASSOCIATED WITH
NEGATIVELY TILTED SHORT WAVE AND DEEPENING SURFACE LOW MOVING
THROUGH THE REGION. SFC LOW EXPECTED TO CONTINUE STRENGTHENING
INTO THE EVENING AS IT MOVES NORTH NEAR THE IN/IL BORDER.
IMPRESSIVE MOISTURE ADVECTION AND NEGATIVE TILT TO SYSTEM
PROVIDING STRONG LIFT AND DEEP MOISTURE PROFILES. CONVECTION OVER
SOUTHERN CONUS MAY HAVE ROBBED SOME MOISTURE BUT AS SYSTEM
STRENGTHENS FURTHER THINK THIS WILL BE OVERCOME THROUGH EARLY
EVENING WITH PCPN AMOUNTS OF HALF TO THREE QUARTERS INCH
POSSIBLE.

DRY SLOT SEEN ON SATELLITE AND IN RADAR MOSAIC WILL MOVE INTO THE
AREA DURING THE MID TO LATE EVENING WITH PCPN DIMINISHING. MAY
SEE SOME DRIZZLE OR VERY LIGHT SHOWERS AT TIMES OVERNIGHT BUT
PCPN CHANCES INCREASE AGAIN TOWARD DAYBREAK AS SECONDARY WAVE
OVER OK THIS AFTERNOON WORKS NORTHEAST. EXPECT SHOWERS TO DEVELOP
EARLY MONDAY WITH LIKELY TO CATEGORICAL POPS WARRANTED THROUGH AT
LEAST MID AFTERNOON UNTIL THIS WAVE PASSES.

TEMPS WERE FALLING INTO THE 50S WITH ONSET OF RAIN AND LATEST
GUIDANCE SUGGEST THEY WILL REMAIN THERE THROUGH THE NIGHT. MAY
SEE A SMALL RISE IN TEMPS MONDAY...ESPECIALLY EAST PRIOR TO
DEEPER COLD AIR ADVECTION.

&&

.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 351 PM EDT SUN APR 19 2015

THE SECOND UPPER LEVEL TROF IN AS MANY DAYS WILL BE MOVING ACROSS
THE FORECAST AREA AT THE START OF THIS PERIOD MONDAY NIGHT. LEFT
A CHANCE FOR LINGERING SHOWERS OVER EASTERN AREAS INCLUDING
MAINLY NORTHWEST OHIO AS THIS SYSTEM MOVES EAST. FOR THE REST OF
THE PERIOD...VERY CHILLY AIR WILL SPREAD OVER THE UPPER GREAT
LAKES REGION AS A NEGATIVE HEIGHT ANOMALY REMAINS OVER SOUTHEAST
CANADA. THERMAL PROFILES SUPPORT A MIX OF PRECIPITATION AT
TIMES...WITH A MIX OF SLEET POSSIBLE LATE TUESDAY GIVEN EXTREMELY
COLD TEMPERATURES ALOFT FOR THIS TIME OF YEAR WITH THE WET BULB
ZERO REMAINING BELOW 3K FEET. THE GFS HAS TRENDED THE LOW LEVEL
MORE UNSTABLE TUESDAY AFTERNOON DURING THE PAST FEW RUNS WITH
LAPSE RATES FROM ABOUT 8.5C TO 10C PER KM FROM THE SURFACE TO 600
MB WITH LIMITED CAPE NOW SHOWING UP. KEPT A CHANCE FOR SHOWERS
NORTHEAST AREAS TUESDAY AFTERNOON GIVEN THESE CONDITIONS. LEFT
SLEET OUT FOR NOW GIVEN LINGERING UNCERTAINTIES ABOUT PRECIP TYPE
WITH AFTERNOON TEMPERATURES CLIMBING INTO THE LOW TO MID 50S.

GIVEN SOME RECENT ADVANCEMENT CONCERNING SPRING GROW IN SENSITIVE
PLANTS AND FRUIT TREES DUE TO WARM TEMPERATURES...HAVE UPDATED
THE HAZARDOUS WEATHER OUTLOOK EARLIER TODAY TO HIGHLIGHT FROST
AND FREEZE CONCERNS DURING THIS WEEK. HAVE TRENDED DOWN MOST HIGH
AND LOW TEMPS IN ACCORDANCE WITH THE LATEST SUPERBLEND GIVEN GFS
AND ECMWF 850 MB TEMPS STAYING BELOW ZERO AFTER TUESDAY. HIGHS
SHOULD BE MAINLY IN THE LOW TO MID 50S AND LOWS IN THE LOW TO MID
30S...WITH SOME MID TO UPPER 20S POSSIBLE WEDNESDAY NIGHT THROUGH
FRIDAY NIGHT.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 124 AM EDT MON APR 20 2015

990MB SURFACE LOW CURRENTLY MOVING OVER KSBN AND WILL CONTINUE TO
LIFT NORTHEAST...ALONG WITH STEADIER RAIN. STILL PLENTY OF LOW
LEVEL MOISTURE IN PLACE THOUGH AND IFR/LIFR CEILINGS WILL LIKELY
PERSIST THROUGH MUCH OF THE EARLY MORNING. LATEST SATELLITE DOES
SHOW A BRIEF BREAK IN CLOUD COVER UPSTREAM THAT COULD BRING
PERIODIC IMPROVEMENTS AT KFWA THROUGH 12Z BUT LATEST FORECAST
SOUNDINGS WARRANT CONTINUATION OF MORE PESSIMISTIC APPROACH.
SECONDARY SHORTWAVE WILL THEN LIFT THROUGH THE AREA FROM 12Z-18Z
AND WILL BRING ANOTHER ROUND OF RAIN AND AT LEAST LOW END MVFR
CONDITIONS. STEADY IMPROVEMENT EXPECTED BY AFTERNOON THOUGH AS
THIS WAVE LIFTS NORTH AND DRIER AIR BEGINS TO FILTER INTO THE
REGION. EXPECT STRONG W/SW GUSTS TODAY IN WAKE OF DEEPENING LOW
PRESSURE.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY FROM 11 AM THIS MORNING TO 10 PM EDT THIS
     EVENING FOR LMZ043-046.

&&

$$

SYNOPSIS...MURPHY
SHORT TERM...LASHLEY
LONG TERM...SKIPPER
AVIATION...AGD


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