Area Forecast Discussion
Issued by NWS Northern Indiana

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
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 150501
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
101 AM EDT WED APR 15 2015

.SYNOPSIS...
ISSUED AT 100 AM EDT WED APR 15 2015

HIGH PRESSURE CENTERED OVER THE UPPER LAKES WILL CONTINUE TO
PROVIDE THE AREA WITH DRY EASTERLY WINDS TODAY INTO THIS EVENING.
A WEAK UPPER LEVEL SYSTEM AND SURGE OF MOISTURE WILL BRING SHOWER
CHANCES BACK INTO THE FORECAST LATER TONIGHT INTO THURSDAY. HIGHS
WILL REACH THE 60S BOTH TODAY AND THURSDAY...WITH LOWS TONIGHT
FORECAST TO DROP INTO THE 40S.

&&

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 323 PM EDT TUE APR 14 2015

QUIET AND DRY WEATHER CONTINUES TONIGHT AND WEDNESDAY WITH HIGH
PRESSURE CENTERED OVER THE GREAT LAKES. CIRRUS CANOPY FROM
CONVECTION TO OUR SOUTH HAS BEEN RATHER PERSISTENT AND THICK TODAY
BUT SATELLITE SHOWING SOME THINNING AND CLEARING TAKING PLACE THIS
AFTERNOON. MODEL CROSS SECTIONS SUGGEST THIS TREND TO CONTINUE
THROUGH THE EVENING BUT MAY SEE SOME SCT-BKN CIRRUS REMAINING. HAVE
CONTINUED TREND OF SLOWING DOWN CLEARING BUT DO HAVE PARTLY CLOUDY
SKIES THIS EVENING FOLLOWED BY MOSTLY CLEAR OVERNIGHT.

MOSTLY SUNNY EXPECTED TO START THE DAY WEDNESDAY BUT EXPECT HIGH
CLOUDS TO INCREASE ONCE AGAIN IN AFTERNOON AHEAD OF NEXT SYSTEM AS
HIGH PRESSURE DRIFTS EAST. GRADIENT TO INCREASE AND WILL SEE 10 TO
20 MPH WINDS DURING THE DAY.


&&

.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 323 PM EDT TUE APR 14 2015

SOMEWHAT ZONAL FLOW FOR THE FIRST HALF OF THE LONG TERM PERIOD WITH
A FEW WEAK RIPPLES EJECTING OUT OF THE UPPER LOW CLOSING OFF OVER
THE FOUR CORNERS REGION TONIGHT. FIRST OF THESE WAVES WILL MOVE IN
LATE WEDNESDAY NIGHT INTO THURSDAY. IT WILL TAKE AWHILE FOR THE
COLUMN TO SATURATE GIVEN THE VERY DRY ANTECEDENT AIRMASS. THUS HAVE
KEPT BETTER POPS AFTER 12Z ONCE LOW LEVEL FLOW VEERS SOUTHERLY AND
BETTER MOISTURE IS ADVECTED INTO THE AREA. BOTH MID-LEVEL LAPSE
RATES AND SURFACE BASED INSTABILITY WILL BE MEAGER...BUT GIVEN THE
DECENT MOISTURE ADVECTION CANNOT RULE OUT A FEW ISOLATED RUMBLES OF
THUNDER...SO KEPT INHERITED SLIGHT CHANCE THUNDER MENTION DURING THE
DAY ON THURSDAY. LOW LEVEL MOISTURE WILL REMAIN ACROSS THE AREA ON
FRIDAY...BUT SUBSIDENCE BENEATH THE SHORTWAVE RIDGING IN THE WAKE OF
THE THURSDAY WAVE SHOULD KEEP MOST OF THE AREA DRY ON FRIDAY.

MADE NO CHANGES TO SUPERBLEND BEYOND FRIDAY GIVEN THE TEMPORAL
UNCERTAINTY REGARDING THE EJECTION OF THE CUT OFF LOW OUT OF THE
SOUTHWESTERN US. 12Z GFS IS MUCH STRONGER WITH THE NORTHERN STREAM
WAVE MOVING ALONG THE US/CANADA BORDER ON FRIDAY AND INTERACTS WITH
THE CUT OFF LOW RESULTING IN A MORE PROGRESSIVE PATTERN WHILE THE
ECMWF AND GEM ARE WEAKER WITH THIS WAVE AND THE SATURDAY/SAT NIGHT
NORTHERN STREAM WAVE THEN PHASES WITH THE CUT OFF LOW TO OUR
NORTHWEST. FAVOR THE SLOWER ECMWF/GEM SOLUTION GIVEN THE GFS
TENDENCY TO BE A BIT TO PROGRESSIVE. FWIW...12Z NAM AT 84 HOURS ALSO
FAVORS THE WEAKER NORTHERN STREAM WAVE/SLOWER EJECTION OF THE FOUR
CORNERS CUT OFF LOW. REGARDLESS OF THE TIMING...UNSETTLED WEATHER IS
EXPECTED IN OUR AREA ONCE THIS CUTOFF LOW PHASES WITH THE NORTHERN
STREAM.

AN EARLY LOOK AT NEXT WEEK INDICATES THE POTENTIAL FOR COOL
TEMPERATURES AS BOTH THE GFS AND ECMWF HAVE OUR AREA LOCKED IN TO A
NORTHWEST FLOW PATTERN FOR A MAJORITY OF THE WEEK. THIS WILL BECOME
MORE CLEAR ONCE MODELS BETTER RESOLVE THE EVOLUTION OF THE CUT OFF
LOW THIS WEEK INTO THE WEEKEND...BUT EARLY INDICATIONS ARE FOR HIGH

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 100 AM EDT WED APR 15 2015

VFR/DRY EXPECTED THROUGH THE TAF CYCLONE IN STABLE/INCREASING
EASTERLY SFC FLOW. WINDS MAY GUST 20-25 KTS AT TIMES THIS
AFTERNOON AS BOUNDARY LAYER DEEPENS AND PRESSURE GRADIENT
GRADUALLY TIGHTENS BETWEEN A 1030 MB HIGH DRIFTING INTO SE CANADA
AND WEAK SFC TROUGH ACROSS THE LOWER MS VALLEY.
OTHERWISE...EXPECT CLOUDS/MOISTURE TO REMAIN CONFINED TO UPPER
LEVELS TODAY...LOWERING/THICKENING SOME TOWARD THE END OF THE
PERIOD WITH INITIAL SURGE OF MID LEVEL THETA-E ADVECTION.

&&

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

$$

SYNOPSIS...STEINWEDEL
SHORT TERM...LASHLEY
LONG TERM...BENTLEY
AVIATION...STEINWEDEL


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

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.