Area Forecast Discussion
Issued by NWS Northern Indiana

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000
FXUS63 KIWX 190820
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
420 AM EDT TUE AUG 19 2014

.SYNOPSIS...
ISSUED AT 138 AM EDT TUE AUG 19 2014

LOW PRESSURE AND A SLOW MOVING COLD FRONT WILL APPROACH THE REGION
TODAY. AS IT DOES...THE CHANCES FOR SHOWERS AND THUNDERSTORMS
WILL INCREASE THIS AFTERNOON...STARTING ACROSS WESTERN INDIANA
AND MICHIGAN AND SPREADING EAST. SEVERE STORMS ARE POSSIBLE THIS
AFTERNOON. ANY SHOWERS AND STORMS WILL BE CAPABLE OF LOCALLY HEAVY
RAIN. HIGHS TODAY WILL BE IN THE LOWER TO MID 80S. LOWS TONIGHT
WILL BE AROUND 65.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 415 AM EDT TUE AUG 19 2014

THE EARLY MORNING SETUP FOR FOG IS FAVORABLE AGAIN WITH CLEAR
SKIES...LIGHT WINDS AND PLENTY OF LOW LEVEL MOISTURE. UPSTREAM
CLOUDS WILL ARRIVE TOO LATE TO HAVE MUCH OF AN EFFECT SO HAVE ADDED
AREAS OF FOG OVER FAR WEST AREAS EARLY THIS MORNING. THE FOGGY
CONDITIONS WILL IMPROVE EARLY THIS MORNING AS LOW LEVEL FLOW
INCREASES AND THE FOG MIXES OUT WITH DAYTIME HEATING. AN UPPER LEVEL
LOW AND ASSOCIATED TROF WILL MOVE INTO THE UPPER MIDWEST TODAY...AND
PROVIDE A MORE FAVORABLE ENVIRONMENT FOR THUNDERSTORMS OVER THE
FORECAST AREA. FAVOR THE 4KM NAM/WRF THAT APPEARS TO HAVE THE BEST
HANDLE ON THE DEVELOPMENT OF CONVECTION EARLY THIS MORNING...AND THE
REDEVELOPMENT OF STORMS LATER TODAY ALONG THE EARLIER OUTFLOW
BOUNDARY. HAVE MADE SUBSTANTIAL CHANGES TO THE GRIDS/FORECAST IN
THIS REGARD. AFTERNOON CAPE VALUES SHOULD APPROACH 3000 J/KG...AND
BRING THE POTENTIAL FOR SEVERE STORMS AS LOW TO MID LEVEL FLOW
INCREASES AND BETTER SUPPORTS THE DEVELOPMENT FOR SEVERE STORMS.
RAISED HIGHS A LITTLE TODAY. FAVOR THE WARMER GFS/MAV AS
TEMPERATURES WILL BE STARTING OUT WELL INTO THE 60S WITH 850 MB
TEMPS AROUND 18C.

&&

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 415 AM EDT TUE AUG 19 2014

DECENT MODEL AGREEMENT NOTED ALOFT THIS PD ESP W/EXPANDING UPR RIDGE
CNTRD OVR THE LWR MS VALLEY. HWVR DETAILS W/NRN CONUS FLW REMAIN A
CONVOLUTED MESS. REGARDLESS SYNOPTIC PATTN OF EXPANDING UPR RIDGE
SEWD OF PROGRESSIVE NRN STREAM FLW THROUGH SRN CANADA WILL ALLOW SFC
FNTL ZONE TO BUCK BACK NWD INTO THE NRN LAKES THIS WEEKEND.

START OF PD ON WED XPCD TO BE TRANQUIL IN WAKE OF EWD WKNG UPR LOW
ACRS THE NRN LAKES. WILL HOLD W/A TOKEN LOW CHC POP ACRS NE CWA WED
AFTN IN SPIRIT OF COLLABORATION BUT LL DRYING AND BURGEONING HGT
RISES ALOFT SHLD QUELL ANY SHOWER DVLPMNT. EWD FOLD OF UPR RIDGE WED
NIGHT AND ASSOCD EWD ADVTN OF LL THETA-E RIDGE OUT OF THE PLAINS
WILL LIKELY YIELD SOME STORMS AFT MIDNIGHT FAR SWRN ZONES AND BUMPED
PRIOR POPS THERE WHILE HOLDING W/LOW TO SLGT CHC MENTION ELSEWHERE.
SOME OF THIS MAY BLEED OVR INTO THU AM AS SFC BNDRY MIXES BACK NWD
THROUGH THE CWA. NOT PARTICULARLY IMPRESSED W/PRECIP CHCS OWING TO
BOTH LG SCALE HGT RISES ALOFT AND GENERAL CAPPING DVLPG UNDERNEATH
WARM LYR ALOFT.

ADDNL WARMING ALOFT XPCD ON FRI-SUN AS UPR RIDGE BLDS FURTHER. NO DOUBT
SIG MID LVL CAPPING LIKELY AND W/GENERAL CONSENSUS INDICATING WK
MASS FLUX ACRS THE SRN LAKES WILL CUT PRIOR EXISTING MENTIONABLE
POPS ACRS THE BOARD. OTRWS WARMEST AIR OF THE SUMMER XPCD THIS
WEEKEND.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 138 AM EDT TUE AUG 19 2014

AN UPPER LEVEL LOW AND ASSOCIATED TROF WILL MOVE INTO THE UPPER
MIDWEST TODAY...AND PROVIDE A MORE FAVORABLE ENVIRONMENT FOR
THUNDERSTORMS OVER THE FORECAST AREA. BEFORE THIS...AREAS OF FOG
HAD ALREADY DEVELOPED OVER THE WESTERN PART OF THE AREA. THE FOGGY
CONDITIONS WILL IMPROVE EARLY THIS MORNING AS UPSTREAM CLOUDS
SPREAD OVER THE AREA AND AS LOW LEVEL FLOW INCREASES. RVR SENSORS
AT SBN INDICATE GROUND FOG IN THE AREA...SO CONDITIONS MAY DROP
BRIEFLY LOWER THAN INDICATED ON THE TAF. ADDED THUNDER TO SBN TAF
GIVEN MORE FAVORABLE ENVIRONMENT BY LATE TODAY.

&&

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

$$

SYNOPSIS...SKIPPER
SHORT TERM...SKIPPER
LONG TERM...T
AVIATION...SKIPPER


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