Area Forecast Discussion
Issued by NWS Northern Indiana

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS63 KIWX 040634
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
234 AM EDT WED MAY 4 2016

.SYNOPSIS...
ISSUED AT 340 PM EDT TUE MAY 3 2016

RAIN WILL RETURN TO THE AREA LATE TONIGHT AS ANOTHER COLD FRONT
SWEEPS THROUGH THE REGION. SHOWERS WILL THEN CONTINUE THROUGH
THURSDAY MORNING ALONG WITH COOL AND BREEZY CONDITIONS. HIGH
PRESSURE BRINGS WARMER AND DRIER CONDITIONS ON FRIDAY BUT ANOTHER
FRONT WILL ARRIVE ON SATURDAY WITH ANOTHER CHANCE OF RAIN.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 230 AM EDT WED MAY 4 2016

WATER VAPOR IMAGERY DEPICTING DEEP UPPER TROF OVER THE NORTHERN
GREAT LAKES REGION WITH POTENT SHORT WAVE ENERGY APPROACHING THE
BASE OF THE TROF. THIS IS COMBINING WITH STRONG MASS CONVERGENCE
ALONG ASSOCIATED SURFACE COLD FRONT TO GENERATE AREA OF SHOWERS
AND THUNDERSTORMS ACROSS SOUTHERN WISCONSIN MOVING INTO NORTHERN
ILLINOIS TONIGHT. UPPER TROF WILL DIG SOUTH AND CLOSE OFF OVER
SOUTHERN GREAT LAKES BY MIDDAY TODAY...BRINGING 100M HEIGHT FALLS
AND -26C COLD POOL OVER THE AREA WHICH WILL CONTINUE TO SUPPORT
SHOWERS AND THUNDERSTORMS AHEAD OF COLD FRONT THAT WILL SWEEP
ACROSS THE AREA TODAY. EXPECT NON-DIURNAL EARLY MORNING HIGH TEMP
IN WESTERN CWA WITH ARRIVAL OF COLD FRONT AROUND 12Z THIS MORNING
AND STRONG CAA ON GUSTY NW WINDS BEHIND FRONT WILL HAVE TEMPS
STEADY/SLOWLY FALLING DURING THE DAY. PRECIP LINGERS INTO
WEDNESDAY NIGHT AS MOISTURE WRAPS AROUND CYCLONIC FLOW WITH UPPER
LOW DROPPING SOUTHEAST INTO OHIO VALLEY.

&&

.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 230 AM EDT WED MAY 4 2016

GRADUALLY IMPROVING CONDITIONS TO BEGIN ON THURSDAY AS INFLUENCE
OF UPPER LOW WANES AS IT CONTINUES SOUTHEAST TOWARD THE MID
ATLANTIC. RIDGING...SURFACE AND ALOFT WILL BUILD IN FROM THE WEST
AND LEAD TO GRADUALLY CLEARING SKIES OVER THE WESTERN CWA BY
THURSDAY AFTERNOON. FAIR WEATHER WILL CONTINUE ON FRIDAY AS TEMPS
WARM BACK INTO THE 70S. NORTHERN STREAM SYSTEM MOVING ACROSS
SOUTHERN CANADA WILL DRAG A WEAK SURFACE COLD FRONT THROUGH THE
AREA ON SATURDAY. UPPER SUPPORT REMAINS DETACHED TO THE NORTH AND
LOW LEVEL FORCING WEAKENS AS FRONT TAKES ON EAST/WEST ORIENTATION
AS IT MOVES THROUGH. FRONT WILL ALSO BE LACKING IN MOISTURE AS
SURFACE HIGH PRESSURE WILL BE ANCHORED OVER GULF OF MEXICO.
THEREFORE LOW CONFIDENCE IN PRECIP DEVELOPING AND WILL CUT POPS
FROM SUPERBLEND TO SMALL CHANCE. FOCUS THEN SHIFTS TO UPPER LOW
THAT WILL BE LIFTING OUT OF THE FOUR CORNERS ON SUNDAY. DOWNSTREAM
RIDGING RESULTING FROM THIS SYSTEM WILL HAVE OUR AREA DRY SUNDAY
AND MONDAY. MEDIUM RANGE MODELS OFFERING VARYING SOLNS HANDLING
UPPER LOW BUT AGREEMENT CAN BE FOUND WITH A SLOWER TREND FOR
BRINGING PRECIP BACK INTO THE AREA...AND THIS IS REFLECTED IN
SUPERBLEND POPS AS WELL WITH ONLY SLIGHT CHANCE UNTIL TUESDAY.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1230 AM EDT WED MAY 4 2016

AN UPPER LEVEL TROF WILL MOVE SOUTH ACROSS THE MIDWEST TODAY.
AHEAD OF THIS SYSTEM...A COLD FRONT WILL MOVE ACROSS NORTHERN
INDIANA AND BE ACCOMPANIED BAY SHOWERS AND LOWER CEILINGS. AT
04Z...A CLUSTER OF THUNDERSTORMS WAS OVER FAR SW WI AND EXTREME NE
IA. THE STORMS WERE JUST ENTERING NW IL. THE LATEST NAM AND ARW
BUFKIT FORECAST SOUNDINGS OVER NRN INDIANA LIMIT MID LEVEL
INSTABILITY TO 50 J/KG. SPC MOST UNSTABLE CAPES WERE VIRTUALLY
ZERO OVER THE ENTIRE REGION...SO EXPECT THE STORMS WILL PASS BY TO
THE WEST OF THE TERMINALS WHERE THE BEST UPPER LEVEL SUPPORT WILL
REMAIN.

MADE SOME MINOR CHANGES TO THE ONGOING TAFS IN REGARD TO THE
TIMING OF THE FRONT AND SUBSEQUENT ARRIVAL OF LOW CLOUDS. AN
UPPER LEVEL LOW WILL DRIFT SOUTH OVER THE AREA LATER TODAY BEHIND
THE FRONT AND SHOULD KEEP CONDITIONS FROM BECOMING VFR. TAFS MAY
BE TOO OPTIMISTIC WITH MVFR CONDITIONS LATE IN THE TAF PERIOD.
GUT FEELING WITH THE UPPER LEVEL LOW AND RESIDUAL MOISTURE OVER
THE AREA...CONDITIONS MAY BECOME IFR LATE IN THE TAF PERIOD.


&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY FROM 5 AM TO 5 PM EDT THURSDAY FOR LMZ043-
     046.

     GALE WARNING FROM 6 AM THIS MORNING TO 5 AM EDT THURSDAY FOR
     LMZ043-046.

&&

$$

SYNOPSIS...AGD
SHORT TERM...JAL
LONG TERM...JAL
AVIATION...SKIPPER


VISIT US AT WWW.WEATHER.GOV/IWX

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.