Area Forecast Discussion
Issued by NWS Northern Indiana

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000
FXUS63 KIWX 261544
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
1144 AM EDT FRI JUN 26 2015

.SYNOPSIS...
ISSUED AT 1140 AM EDT FRI JUN 26 2015

AN AREA OF SHOWERS WITH A FEW EMBEDDED THUNDERSTORMS IS EXPECTED
TO DEVELOP THIS AFTERNOON AND CONTINUE THROUGH SATURDAY AS A LOW
PRESSURE SYSTEM MOVES TOWARD OHIO. HEAVY RAIN AND FLASH FLOODING
ARE POSSIBLE MAINLY ALONG AND SOUTH OF HIGHWAY 24. HIGHS WILL BE
IN THE LOW TO MID 70S FRIDAY AND UPPER 60S TO LOWER 70S SATURDAY.LOWS
WILL BE IN THE UPPER 50S TO LOWER 60S.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 428 AM EDT FRI JUN 26 2015

EARLY STAGES OF PRONOUNCED LONGWAVE PATTERN AMPLIFICATION ALREADY
UNDERWAY THIS MORNING AS SEASONABLY STRONG PACIFIC JET SNAKES IT
WAY THROUGH NOAM. THIS JET WILL CONTINUE TO CARVE OUT A DECENT PV
ANOMALY OVER THE SOUTHERN GREAT LAKES THROUGH THE SHORT TERM
PERIOD AND WILL COUPLE WITH OUTGOING EASTERN LAKES JET TO SUPPORT
STRENGTHENING/LIFTING FRONTAL BOUNDARY AND SURFACE CYCLOGENESIS BY
LATER TONIGHT. MORE WIDESPREAD PRECIP WILL EXPAND NORTHWARD BY THE
EARLY AFTERNOON AS 300K ISENTROPIC ASCENT RAMPS UP. SURFACE
BAROCLINIC ZONE STAYS SUFFICIENTLY FAR SOUTH TO KEEP OUR CWA
PRIMARILY IN A COOL/STABLE REGIME WITH A NOTABLE "SPEED BUMP"
AROUND 600MB ALSO KEEPING MUCAPE VALUES IN CHECK. WOULDN`T RULE
OUT A FEW EMBEDDED THUNDERSTORMS GIVEN POCKETS OF MUCAPE ~500 J/KG
BUT COVERAGE OF THUNDER SHOULD BE LIMITED...ESPECIALLY IN OUR
NORTHERN HALF. LACK OF MORE PROMINENT STATIC INSTABILITY WILL BE
MORE THAN MADE UP FOR BY SYNOPTICALLY FORCED ASCENT GIVEN GOOD
MIDLEVEL CVA/HEIGHT FALLS...AFOREMENTIONED COUPLED UPPER
JETS...AND TIGHTENING LOW/MID LEVEL THERMAL GRADIENT AS WAVE
APPROACHES AND INTENSIFIES. MOISTURE AVAILABILITY IS ALSO
GOOD...ESPECIALLY IN OUR SOUTHEAST. PW VALUES NOT AS HIGH AS WHAT
WE HAVE SEEN RECENTLY BUT STILL CLIMB TO AROUND 1.75 INCHES IN OUR
FAR SOUTHEASTERN COUNTIES BY THIS EVENING. HAVE THEREFORE RAMPED
POPS UP FOR THE AFTERNOON PERIOD AND CONTINUED WITH CATEGORICAL IN
OUR SOUTHEAST FOR THE OVERNIGHT. MANY AREAS SOUTH OF US-24 COULD
EASILY RECEIVE 1-2 INCHES OF RAIN BY LATE TONIGHT GIVEN
STRENGTH/DURATION OF FORCING IN A MOIST ENVIRONMENT WITH MARGINAL
INSTABILITY.

THIS SETS THE STAGE FOR A DIFFICULT HEADLINE DECISION. MANY AREAS IN
OUR SOUTHEAST REMAIN SATURATED FROM HEAVY RAINS EARLIER THIS MONTH.
SYNOPTICALLY-FORCED PRECIP RATES WILL BE LIGHT ENOUGH TO PREVENT A
TRUE FLASH FLOOD CONCERN BUT ANY POCKETS OF INSTABILITY THAT MANAGE
TO DEVELOP COULD PRODUCE LOCALLY HEAVIER RATES. THE BEST CHANCE OF
THIS WILL UNFORTUNATELY BE IN OUR SOUTHEAST COUNTIES. AREAL FLOODING
WILL ALSO BECOME A CONCERN AS WE HEAD INTO THE OVERNIGHT AND
SATURDAY PERIODS GIVEN LONG DURATION OF STRONG/DEEP DEFORMATION
FORCING. AFTER COORDINATION WITH NEIGHBORING OFFICES AND IN AN
ATTEMPT TO KEEP THE MESSAGE SIMPLE...HAVE DECIDED TO ISSUE A FLASH
FLOOD WATCH FOR OUR SE COUNTIES. CHANCES FOR THUNDER AND HEAVY
PRECIP RATES ARE LOWER IN FORT WAYNE AND POINTS EASTWARD BUT FFG IS
ALSO LOWER THERE AND DECIDED TO GO AHEAD AND INCLUDE THEM IN THE
WATCH.

&&

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 428 AM EDT FRI JUN 26 2015

UNSEASONABLY STRONG LOW PRESSURE SYSTEM EXPECTED TO BE OVER SW OH
SAT MORNING. MOISTURE WRAPPING AROUND THIS SYSTEM SHOULD RESULT IN
SHOWERS CONTG OVER ERN PORTION OF THE CWA THROUGH THE DAY. PWATS
FCST AROUND 1.25" ACROSS ERN PORTION OF THE CWA WITH RATHER STRONG
UVM ASSOCIATED WITH MID LEVEL DEFORMATION ZONE...SO SOME
SUBSTANTIAL RAINFALL AMOUNTS STILL PSBL SATURDAY...MAINLY ACROSS
OUR OH COUNTIES. RAINFALL AND N-NW FLOW WILL KEEP TEMPS WELL BLO
NORMAL WITH HIGHS ONLY IN THE U60S/L70S. SHOWERS EXPECTED TO END
SAT NGT AS LOW PULLS AWAY. SOME CLOUDINESS AND GRADIENT WINDS
STAYING UP MOST IF NOT ALL NIGHT SHOULD LIMIT TEMPS FALLS WITH
LOWS MAINLY IN THE M50S.

RIDGE MOVG ACROSS THE AREA SUNDAY SHOULD PROVIDE FAIR WX MOST IF NOT
ALL DAY... BUT ANOTHER SHRTWV EXPECTED TO DROP SEWD DOWN BACKSIDE OF
DEEP HUDSON BAY-GRTLKS TROF BRINGING A SLIGHT CHC OF SHOWERS/TSTMS
BACK INTO WRN PORTIONS OF THE CWA SUNDAY AFTN... WITH SHOWERS LIKELY
ACROSS THE AREA SUNDAY NIGHT-MONDAY AS THIS SYSTEM MOVES THROUGH.
TEMPS WILL MODERATE SOME FROM THE COOL SATURDAY READINGS... BUT WILL
STILL BE BLO NORMAL SUNDAY WITH HIGHS IN THE M70S...ONLY FALLING
INTO THE L60S SUNDAY NIGHT AS WAA AHEAD OF SHRTWV/CDFNT OVERSPREADS
THE AREA.

UPR LEVEL TROF EXPECTED TO PERSIST ACROSS ERN CANADA/NE U.S. NEXT
WEEK WITH A SERIES OF WK SHRTWVS DROPPING SE ACROSS THE GRTLKS. SOME
DIFFERENCES IN TIMING OF THESE SYSTEMS BETWEEN MODELS NECESSITATES
KEEPING AT LEAST A SLIGHT CHC OF SHOWERS IN THE FCST EACH DAY. TEMPS
WILL REMAIN A BIT BLO NORMAL WITH HIGHS GENERALLY IN THE M-U70S AND
LOWS IN THE U50S/L60S.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 602 AM EDT FRI JUN 26 2015

IFR CONDITIONS CURRENTLY IN PLACE SHOULD GRADUALLY IMPROVE AFTER
SUNRISE AS DIURNAL MIXING BEGINS. HOWEVER...MVFR CONDITIONS WILL
LIKELY PREVAIL THROUGH MUCH OF THE PERIOD AS STRONG MID/UPPER
LEVEL TROUGH APPROACHES AND ASSOCIATED LOW LEVEL FRONT
STRENGTHENS. RAIN IS EXPECTED TO SPREAD ACROSS THE AREA BY THE
AFTERNOON WITH A FEW EMBEDDED THUNDERSTORMS POSSIBLE AT KFWA.
SURFACE BOUNDARY WILL REMAIN SOUTH OF THE AREA AND LOW LEVEL
MOISTURE BENEATH FRONTAL INVERSION WILL LIKELY KEEP CEILINGS
HOVERING NEAR MVFR CATEGORY. CONFIDENCE IS NOT HIGH ENOUGH TO
INCLUDE FUEL ALTERNATE AT THIS POINT...THOUGH MAY BE POSSIBLE.


&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...FLASH FLOOD WATCH THROUGH SATURDAY MORNING FOR INZ018-022>027-
     032>034.

MI...NONE.
OH...FLASH FLOOD WATCH THROUGH SATURDAY AFTERNOON FOR OHZ004-005-015-
     016-024-025.

LM...NONE.
&&

$$

SYNOPSIS...MF
SHORT TERM...AGD
LONG TERM...JT
AVIATION...AGD


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