Area Forecast Discussion
Issued by NWS Indianapolis, IN

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 KIND 060715
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
215 AM EST SAT FEB 6 2016

.UPDATE...
THE LONG TERM SECTION HAS BEEN UPDATED BELOW

&&

.SYNOPSIS...
ISSUED AT 306 PM EST FRI FEB 5 2016

MAINLY DRY AND SEASONABLY MILD CONDITIONS ARE EXPECTED THROUGH THE
WEEKEND WITH HIGH PRESSURE PREDOMINANTLY IN CONTROL. A DEEPENING
UPPER LOW WILL DIVE INTO THE REGION EARLY NEXT WEEK AND BRING A
TRANSITION TO A COLDER AND SNOWIER PATTERN FOR CENTRAL INDIANA
THROUGH THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /REST OF TONIGHT/...
ISSUED AT 947 PPM EST FRI FEB 5 2016

.UPDATE...WEAK RIDGE OF HIGH PRESSURE CURRENTLY MOVING EAST ACROSS
OUR REGION.  SHOULD REMAIN MOSTLY CLEAR OVER SOUTHERN SECTIONS
UNTIL VERY LATE TONIGHT. OTHERWISE...WENT PARTLY CLOUDY ELSEWHERE.
TEMPERATURES MAY DROP ANOTHER DEGREE OR TWO BEFORE LEVELING OFF.
OTHERWISE...CURRENT FORECAST IS ON TRACK.

PORTION OF PREVIOUS NEAR TERM DISCUSSION FOLLOWS...
TEMPS...TOOK A MOS BLEND FOR LOWS OVERNIGHT CONSIDERING PERIODIC
CLOUDS. SHOULD THE BULK OF THE CLOUDS ASSOCIATED WITH THE WAVE ALOFT
HOLD OFF UNTIL CLOSER TO DAYBREAK OR AFTER...MAY SEE LOWS
TREND TOWARDS COOLER MAVMOS.

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
ISSUED AT 306 PM EST FRI FEB 5 2016

FORECAST CHALLENGES FOCUS ON SNOW CHANCES MONDAY AS A COLDER AND
MORE UNSETTLED WEATHER PATTERN DEVELOPS TO BEGIN THE NEW WORK WEEK.

FIRST THOUGH...A MAINLY DRY AND SEASONABLY MILD PATTERN WILL
CONTINUE FOR MOST OF THE WEEKEND AS THE OHIO VALLEY RESIDES IN A
FAST QUASI-ZONAL FLOW ALOFT. THE AFOREMENTIONED UPPER WAVE WILL
TRANSITION ACROSS THE REGION SATURDAY IN AN INCREASINGLY WEAKENED
STATE. ENERGY ALOFT WILL SPLIT BETWEEN A STRONGER UPPER WAVE
TRACKING THROUGH THE LOWER MISSISSIPPI VALLEY AND A SURFACE LOW
MOVING THROUGH ONTARIO AND QUEBEC. THE LACK OF APPRECIABLE FORCING
ALOFT COMBINED WITH POOR MOISTURE ADVECTION WILL KEEP IMPACTS
MINIMAL WITH THE PASSAGE OF THE WAVE THROUGH THE AREA. CANNOT
ENTIRELY RULE OUT A FEW SPRINKLES SATURDAY AFTERNOON...OTHERWISE
JUST ANTICIPATING A PERIOD WITH INCREASED CLOUDS THROUGH EARLY
AFTERNOON WITH INCREASING SUNSHINE LATER IN THE DAY. DRY WEATHER
WILL CONTINUE SATURDAY NIGHT AND SUNDAY AS RIDGING AT THE SURFACE
AND ALOFT BRIEFLY ESTABLISH OVER THE OHIO VALLEY.

A STRENGTHENING UPPER LOW WILL DIVE OUT OF THE CANADIAN PRAIRIES
SATURDAY NIGHT AND EXPAND INTO THE GREAT LAKES BY MONDAY. THE UPPER
LOW WILL PROGRESSIVELY DEEPEN AND CARVE OUT A SHARP TROUGH POISED TO
ENCOMPASS THE EASTERN HALF OF THE COUNTRY TO START THE NEW WEEK.
THIS WILL BRING AN ABRUPT RETURN BACK TO WINTER WEATHER FOR CENTRAL
INDIANA BEGINNING MONDAY AND LIKELY CONTINUING FOR MUCH OF NEXT WEEK.

INITIALLY...MOISTURE DRAWN NORTH INTO THE REGION LATE SUNDAY WILL
ENABLE AN INCREASE IN CLOUD COVERAGE...BUT PRECIPITATION IS LIKELY
TO HOLD OFF UNTIL AFTER DARK AS ISENTROPIC LIFT BECOMES MORE
ESTABLISHED. LOW LEVEL THERMALS SUPPORT PRECIP IN THE FORM OF RAIN
SUNDAY EVENING GRADUALLY TRANSITIONING TO SCATTERED SNOW SHOWERS IN
THE PREDAWN HOURS MONDAY AS COLDER AIR ADVECTS INTO THE REGION
AROUND THE BASE OF THE APPROACHING UPPER LOW. WITH THE EXCEPTION OF
POSSIBLY FAR SOUTHEASTERN COUNTIES...LOW LEVEL THERMAL ANALYSIS
STRONGLY SUGGESTIVE THAT PRECIP WILL BE IN THE FORM OF ALL SNOW BY
12Z MONDAY.

MODEL CONSENSUS FAVORS THE UPPER LOW SETTLING OVER THE REGION
MONDAY...WITH SCATTERED SNOW SHOWERS EXPECTED TO BECOME WIDESPREAD
THROUGH THE COURSE OF THE DAY AS SUBTLE INSTABILITY AND STEEPENING
LAPSE RATES CONTRIBUTE TO THE STRONG FORCING PRESENT IN THE MID
LEVELS. WHILE WOULD LIKE TO SEE A SLIGHTLY MORE FAVORABLE LOOK TO
THE SOUNDINGS...CERTAINLY THINK WE MAY BE LOOKING AT A HIGH IMPACT/
LOW ACCUMULATION SCENARIO MONDAY WITH SNOW SHOWERS AND SQUALLS
SCATTERED ALL DAY. THE PRESENCE OF A FEW HOURS WITH THE DENDRITIC
GROWTH ZONE AT 50-100MB DEPTH DURING THE AFTERNOON MAY ENHANCE
SNOWFALL RATES WITH RATIOS CLOSER TO 15 OT 1 BY LATE DAY.

ADDING TO THE POTENTIAL IMPACTS WILL BE STEADY TO SLOWLY FALLING
TEMPS DURING THE DAY AS COLD ADVECTION STRENGTHENS. EXPECT TEMPS INTO
THE UPPER 20S AND LOWER 30S BY SUNSET MONDAY. WILL CARRY HIGH CHANCE
POPS AND BEEF UP WORDING FOR IMPACTS IN THE HWO. POTENTIAL FOR 1 TO
2 INCHES IN SOME AREAS BY MONDAY EVENING...WITH THE PRESENCE OF A
TROWAL BENDING BACK INTO THE AREA MONDAY NIGHT POSSIBLY MAINTAINING
ENHANCED SNOW SHOWERS MONDAY NIGHT.

TEMPS...GENERALLY TRENDED TOWARDS THE WARMER MAVMOS FOR HIGHS OVER
THE WEEKEND AS TEMPS HAVE OVERACHIEVED THE LAST FEW DAYS WHEN THE
SUN HAS BEEN PRESENT. INDICATED MORNING HIGHS ON MONDAY WITH SLOWLY
FALLING TEMPS THE REST OF THE DAY WITH STRONG COLD ADVECTION. USED A
MOS BLEND FOR LOWS THROUGH THE PERIOD.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 215 AM EST SAT FEB 6 2016

MODELS AND ENSEMBLES IN GOOD AGREEMENT THAT THE UPPER TROUGH WILL BE
PUSHING OFF TO THE EAST AT THE START OF THE PERIOD WHICH WILL RESULT
IN LINGERING SMALL SNOW CHANCES ENDING FROM WEST TO EAST LATE
TUESDAY AND TUESDAY NIGHT. THEN...SURFACE HIGH PRESSURE WILL RESULT
IN DRY BUT COLD WEATHER THROUGH THURSDAY NIGHT. REGIONAL BLEND
TEMPERATURES IN THE 20S AND LOWS IN THE TEENS LOOK GOOD WITH COLD
LOW LEVEL THERMALS. COULD BE EVEN A BIT COLDER THAN THE BLEND
DEPENDING ON THE EXPECTED SNOW PACK AND HOW MUCH CLEARING OCCURS.
FINALLY...A CLIPPER SYSTEM COULD BRING MORE LIGHT SNOW TO THE AREA
ON FRIDAY.

&&

.AVIATION /DISCUSSION FOR 060600Z TAF ISSUANCE/...

ISSUED AT 1125 PM EST FRI FEB 5 2016

MVFR CLOUDS AT KLAF HAVE BEEN STUBBORN BUT SHOULD MOVE NORTH AND
SCATTER OUT BY AROUND 8Z. EVERYWHERE ELSE EXPECT VFR THROUGH THE
PERIOD. SMALL POSSIBILITY THE OUTLYING SITES COULD SEE BRIEF
VISIBILITY RESTRICTIONS BUT THINK WITH CIRRUS OVERHEAD WOULD
PREFER TO LEAVE OUT. WITH MOS AND TIME HEIGHTS SHOWING NO CEILING
PROBLEMS AT OTHER SITES SATURDAY WILL GO WITH 5 KFT CEILING WITH
THE UPPER WAVE MOVING THROUGH...BUT WILL NEED TO MONITOR HOW
CLOUDS CURRENTLY ACROSS IOWA AND MINNESOTA DEVELOP AS THEY MOVE
INTO AND THROUGH ILLINOIS SINCE THERE IS MVFR AND IFR IN THAT
DECK.

LIGHT VARIABLE WINDS THROUGH THE NIGHT WILL GIVE WAY TO
SOUTHWESTERLY WINDS AROUND 5-8 KTS BY LATE MORNING.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...RYAN
NEAR TERM...RYAN/JH
SHORT TERM...RYAN
LONG TERM....MK
AVIATION...CP


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