Area Forecast Discussion
Issued by NWS Northern Indiana

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000
FXUS63 KIWX 280559
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
1259 AM EST WED JAN 28 2015

.SYNOPSIS...
ISSUED AT 754 PM EST TUE JAN 27 2015

MOSTLY CLEAR SKIES WILL BRING TEMPERATURES DOWN INTO THE SINGLE
DIGITS AND LOW TEENS. CLOUD COVER WILL INCREASE THROUGHOUT THE DAY
ON WEDNESDAY AS THE NEXT LOW PRESSURE SYSTEM APPROACHES THE AREA.
HIGHS WILL BE IN THE UPPER 20S AND LOW TO MID 30S. EXPECT A WINTRY
MIX OF PRECIPITATION WEDNESDAY NIGHT INTO THURSDAY...WITH MINOR
ICE AND SNOW ACCUMULATIONS POSSIBLE.

&&

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 326 PM EST TUE JAN 27 2015

DEEP LAYERED QG SUBSIDENCE IN WAKE OF AN EXITING EAST COAST TROUGH
WILL CONTINUE TO PROMOTE QUIET/MAINLY CLEAR CONDITIONS INTO
TONIGHT/TOMORROW. ASSOCIATED SFC HIGH SETTLING SOUTH OVER THE AREA
IN TANDEM WITH MAINLY CLEAR SKIES/LIGHT WINDS WILL PRODUCE OPTIMAL
RADIATIONAL COOLING TONIGHT. AS A RESULT CONTINUED TO FAVOR COOLER
GUIDANCE FOR OVERNIGHT LOWS. RETURN SOUTHWEST FLOW BY WEDNESDAY
AFTERNOON AND JUST A GRADUAL INCREASE IN MID-HIGH CLOUDS SHOULD
ALLOW WEDNESDAY HIGHS TO RUN A FEW DEGREES WARMER THAN TODAY.

&&

.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 326 PM EST TUE JAN 27 2015

INITIAL FOCUS WILL BE ON 2 WAVES THAT WILL ATTEMPT TO PHASE SOMEWHAT
ACROSS THE GREAT LAKES INTO THURSDAY. FIRST WAVE WILL BE SCOOTING
OUT OF THE PLAINS AT THE ONSET WITH WEAK CLIPPER MOVING RAPIDLY SE
OUT OF CANADA. PLAINS SYSTEM WILL HAVE A LARGE WARM TONGUE THAT WILL
ACCOMPANY IT AND MOVE INTO THE AREA WEDNESDAY NIGHT. MSTR WILL
INITIALLY BE LIMITED BUT RAPID SATURATION THROUGH 800 MB WILL TAKE
PLACE TOWARDS THURSDAY MORNING. WEDGE OF WARM AIR WILL MOVE IN
BETWEEN 800 AND 900 MB AND COMPLICATE PRECIP TYPE. WARMEST AIR WILL
BE IN PLACE AT THE ONSET WITH COOLING EFFECTS OF SATURATION AS WELL
AS APPROACH OF CANADIAN WAVE ALL LEADING TOWARDS AN EVENTUAL
TRANSITION TO COLDER PROFILES AND CHANGE OVER TO MORE SLEET/SNOW.
NOW WITH ALL THAT BEING SAID...THE BEST LIFT AND DYNAMICS WILL PASS
ACROSS THE FAR NORTHERN PARTS OF THE AREA WITH MAIN IMPACTS ACROSS
LWR MI WHERE PEAK ISENTROPIC LIFT AND FAVORABLE LOW/MID LEVEL LOW
TRACK OCCURS. GRIDS REFLECT A RATHER MESSY SETUP WITH THERMAL
PROFILES STILL HIGHLY SUSPECT CAUSING A LOW CONFIDENCE FORECAST IN
TERMS OF IMPACTS AND DURATION. SFC TEMPS WILL HOVER NEAR OR JUST
BELOW FREEZING MOST OF THE NIGHT BEFORE BEGINNING TO FALL OFF DURING
THE AFTERNOON HOURS OF THURSDAY. ANY PRECIP BY THIS TIME SHOULD
TRANSITION TO ALL SNOW WITH MAYBE A DUSTING IN SOME SPOTS.

TOUCH OF LAKE EFFECT SNOW SHOWERS WILL OCCUR THURSDAY NIGHT AS
STRONG NW FLOW SETS UP. HOWEVER...DESPITE INCREASING DELTA T`S MSTR
WILL BE ON THE DECREASE WHICH SHOULD LIMIT ANY IMPACTS AND KEEP
ACCUMULATIONS ON THE VERY LGT SIDE.

FOCUS SHIFTS TO NORTHERN AND SOUTHERN STREAM SYSTEM AND IMPACTS OVER
THE WEEKEND WITH MODELS STILL HAVING NO CLUE AS TO WHAT MAY EVOLVE.
GFS/ECMWF STILL SUGGEST DECENT CYCLOGENESIS TAKING PLACE MORE EAST
OF THE FORECAST AREA AS TROUGH TAKES ON A NEGATIVE TILT. CHANCES FOR
SOME SNOWFALL LOOK TO BE INCREASING ESPECIALLY INTO PORTIONS OF OHIO
CLOSER TO THE SUGGESTED TRACK. GIVEN TRACK RECORD OF EXTENDED MODELS
THUS FAR THIS MANY DAYS OUT...LOW CONFIDENCE ON WHAT WILL
UNFOLD...RESULTING IN A LOWERING OF BLEND OF MODEL GUIDANCE TO MID
TO HIGH CHANCE POPS FOR NOW. SYSTEM DOES HAVE THE POTENTIAL TO BRING
SEVERAL INCHES OF SNOW TO PARTS OF THE REGION SUNDAY INTO MONDAY SO
WILL NEED TO MONITOR TRENDS AND HOPE MODELS CAN COME TO SOME
AGREEMENT WITH TIME. MUCH COLDER AIR WILL FILTER IN BEHIND THE
SYSTEM WITH HIGHS IN THE SINGLE DIGITS AND TEENS ABOVE AND LOWS AT
OR BELOW ZERO.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1251 AM EST WED JAN 28 2015

LOW LEVEL ANTICYCLONE WILL BRING CONTINUED LIGHT AND VARIABLE
WINDS THROUGH EARLY THIS MORNING. SOUTHEAST WINDS WILL DEVELOP AS
THIS HIGH PRESSURE DEPARTS TO THE EAST TODAY...WITH STRONGEST LATE
AFTERNOON GRADIENT SETTING UP ACROSS NORTHWEST INDIANA WHERE SOME
LATE AFTERNOON SOUTHEAST GUSTS INTO THE 15 TO 18 KNOT RANGE ARE
POSSIBLE. A SOUTHWESTERLY LOW LEVEL JET IN ADVANCE OF NEXT SYSTEM
LATE TONIGHT INTO EARLY THURSDAY WILL ALLOW FOR SOUTHEAST WINDS IN
THE 15G20-25 KNOT RANGE FOR TONIGHT WITH SOME INDICATIONS THAT
LLWS MAY BECOME A CONCERN MAINLY OUTSIDE OF THIS FORECAST PERIOD
IN THE 06Z-12Z TIMEFRAME EARLY THURSDAY MORNING. MID AND HIGH
LEVEL CLOUDINESS TO INCREASE TODAY...WITH DETERIORATING CIGS NOT
ANTICIPATED UNTIL AFTER THIS FORECAST VALID PERIOD. SOME LIGHT
SNOW/RAIN/FREEZING RAIN CONCERNS SHOULD ALSO HOLD OFF UNTIL MAINLY
AFTER THIS FORECAST VALID PERIOD AS NEXT SYSTEM APPROACHES...WHICH
WILL NEED TO BE ADDRESSED IN GREATER DEPTH FOR THE 12Z TAFS.

&&

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

$$

SYNOPSIS...MCD
SHORT TERM...STEINWEDEL
LONG TERM...FISHER
AVIATION...MARSILI


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