Area Forecast Discussion
Issued by NWS Northern Indiana

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000
FXUS63 KIWX 260012
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
812 PM EDT MON MAY 25 2015

.SYNOPSIS...
ISSUED AT 800 PM EDT MON MAY 25 2015

SKIES WILL BE PARTLY TO MOSTLY CLOUDY OVERNIGHT AND LOWS WILL BE
IN THE MID 60S. AN AREA OF LOW PRESSURE WILL BRING SHOWERS AND
SOME THUNDERSTORMS TO THE AREA TUESDAY. HIGHS WILL RANGE FROM THE
MID 70S TO THE LOWER 80S.

&&

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 338 PM EDT MON MAY 25 2015

DRY SLOT ASSOCIATED WITH VORT MAX CURRENTLY LIFTING INTO THE
NORTHERN GREAT LAKES IS BRINGING AN END TO SCT SHOWERS FROM WEST
TO EAST AS PLANNED. MAIN STORY THIS AFTERNOON HAS BEEN GUSTY
WINDS WITH PBL MIXING JUST DEEP ENOUGH TO MIX DOWN SOME GUSTS
AROUND 35 KTS...AIDED IN SOME SPOTS BY LINE OF CONVECTIVE
SHOWERS. LLJ IS GRADUALLY WEAKENING THIS AFTERNOON THOUGH AS
PARENT WAVE LIFTS NORTHEAST AND GRADIENT RELAXES. LATEST SURFACE
OBS INDICATE A SLIGHT DOWNWARD TREND IN AMBIENT WIND GUSTS AND
EXPECT THAT TREND TO CONTINUE AND ACCELERATE INTO THE EVENING
HOURS. SUBTLE SHORTWAVE RIDGING AND LOSS OF DEEPER MOISTURE WILL
KEEP CONDITIONS DRY OVERNIGHT. PARTIAL CLEARING EXPECTED BUT
STEADY SOUTHWEST WIND AND INCREASING CLOUDS TOWARD DAYBREAK
SHOULD KEEP OVERNIGHT LOWS GENERALLY IN THE MID 60S.

ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS IS EXPECTED TOMORROW
AS FORMIDABLE SHORTWAVE CURRENTLY OVER THE SOUTHERN PLAINS LIFTS
NORTHEAST. WAVE WILL BE INCREASINGLY SHEARED AS IT MOVES THROUGH
THE WESTERN GREAT LAKES AND BEST CVA DOES PASS JUST TO OUR
NORTHWEST BUT SHOULD BE ENOUGH FORCED ASCENT TO TOUCH OFF FAIRLY
WIDESPREAD CONVECTION. THIS IS ESPECIALLY TRUE GIVEN EXPECTATION
FOR ANOTHER SURGE IN LOW LEVEL THETA-E WITH INCREASING LLJ.
MODEST DESTABILIZATION WILL ALSO OCCUR WITH INCREASING LOW LEVEL
MOISTURE AND DIURNAL HEATING. MOST OF LATEST GUIDANCE SHOWS AT
LEAST SCT CONVECTION WITH THE BEST CHANCES BEGINNING AROUND NOON
AND CONTINUING THROUGH THE EVENING. INHERITED LIKELY POPS SEEM
APPROPRIATE AND ONLY MINOR CHANGES MADE TO ADD SOME TEMPORAL
DETAIL. SEVERE WEATHER RISK REMAINS LOW. 0-6KM BULK SHEAR VALUES
ARE AROUND 30 KTS WHICH IS MARGINALLY SUPPORTIVE OF ORGANIZED
CONVECTION BUT POOR MIDLEVEL LAPSE RATES LIMIT 0-1KM MLCAPE
VALUES TO AROUND 1000 J/KG OR LESS. A FEW STRONG STORMS MAY
CERTAINLY BE POSSIBLE BUT WIDESPREAD SEVERE WEATHER IS NOT
EXPECTED AT THIS TIME.

&&

.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 338 PM EDT MON MAY 25 2015

SHEARING MID LEVEL SHORTWAVE LIFTING NORTHEAST THROUGH THE
WESTERN/NORTHERN LAKES WILL FORCE A WEAK/TRAILING SFC BOUNDARY
THROUGH THE AREA WEDNESDAY INTO WEDNESDAY EVENING. MODELS IN GOOD
AGREEMENT IN SHUNTING DEEPER MOISTURE EAST OF THE AREA BY THIS
TIME...BUT WITH SOME PARTIAL CLEARING AND BOUNDARY LAYER
HEATING/DESTABILIZATION WOULD EXPECT SCT CONVECTION TO DEVELOP
INVOF THIS FEATURE BY WEDNESDAY AFTERNOON (BEST CHANCES
SOUTHERN/EASTERN ZONES REMOVED FROM STABLE LAKE MI PUSH).

WEAK ANTICYCLONIC FLOW/SHORTWAVE RIDGING WILL PROMOTE A PERIOD OF
FAIR WX LATER WEDNESDAY NIGHT THROUGH FRIDAY MORNING. LITTLE IN
THE WAY OF THERMAL ADVECTION COMBINED WITH AMPLE SUNSHINE WILL
SUPPORT A MILD THURSDAY...ALTHOUGH DIURNAL RANGES WILL BE A
LITTLE GREATER GIVEN INFILTRATION OF SLIGHTLY DRIER AIR. LATER
FRIDAY INTO THE WEEKEND WILL FEATURE RENEWED SHOWER/STORM CHANCES
AS A STRONG NORTHERN STREAM PV ANOMALY TRACKING THROUGH SE CANADA
FORCES AN ACTIVE BAROCLINIC ZONE SOUTH INTO THE LOCAL AREA...WITH
MOISTURE CONVERGENCE/ADVECTION ENHANCED IN ADVANCE OF AN
APPROACHING PLAINS UPPER WAVE.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 810 PM EDT MON MAY 25 2015

CONCERN STILL CENTERS ON STRATUS/LOWER CLOUD DECK DEVELOPMENT AND
EXPANSION LATE TONIGHT. MOIST LOW LEVEL THETA-E AXIS OVERHEAD
AMID MODEST MIXING SHOULD AID FORMATION...THOUGH HELD CONDS HIR
THAN THE IFR CIGS AS SEEN ERLY MON AM ACRS OZARKS...GIVEN DRIER
NEAR SFC ANTECEDENT CONDS ACRS NRN IN. ADDED AFTN SHRA MENTION AT
BOTH SITES TARGETING BEST COVERAGE TIMEFRAME AS SHORTWAVE
/PRESENTLY ACRS RED RIVER VALLEY OF THE SOUTH/ DAMPENS AS IT
TRACKS NEWD INTO SWRN GRTLKS TUE AFTN. OMITTED TSRA MENTION ATTM
GIVEN LACK OF STRONG DESTABILIZATION ACRS NRN IN...WITH WEAK MID
LEVEL LAPSE RATES FURTHER THWARTED BY AM SFC BASED STABLE LYR.
HIR PROB OF MORE ORGANIZED CONVECTION LIKELY TO REMAIN S-SW OF
TAF SITES WITHIN COLLOCATED REGION OF 8H CONVERGENT AXIS/GREATER
INSTABILITY.

&&

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

&&

$$

SYNOPSIS...MURPHY
SHORT TERM...AGD
LONG TERM...STEINWEDEL
AVIATION...MURPHY


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