Area Forecast Discussion
Issued by NWS Indianapolis, IN

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FXUS63 KIND 240227
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
927 PM EST SUN NOV 23 2014

.UPDATE...

THE AVIATION SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 307 PM EST SUN NOV 23 2014

AN AREA OF LOW PRESSURE AND A COLD FRONT WILL BRING RAIN TO CENTRAL
INDIANA TONIGHT INTO MONDAY. BEHIND THE FRONT WILL COME WINDY AND
MUCH COLDER CONDITIONS. ANOTHER SYSTEM COULD BRING SOME LIGHT RAIN
AND SNOW TO THE AREA ON WEDNESDAY. THANKSGIVING INTO SATURDAY WILL
BE COLD AND DRY BEFORE ANOTHER SYSTEM BRINGS LOW CHANCES FOR
PRECIPITATION SUNDAY.

&&

.NEAR TERM.../REST OF THIS AFTERNOON AND TONIGHT/
ISSUED AT 307 PM EST SUN NOV 23 2014

RAIN CONTINUES TO DEVELOP AND OVERSPREAD CENTRAL INDIANA THIS
AFTERNOON AHEAD OF AN UPPER TOUGH AND POTENT VORTICITY MAXIMUM.
EXPECT RAIN TO CONTINUE THROUGH THE AFTERNOON.

RAIN WILL CONTINUE INTO THIS EVENING WITH THE UPPER TROUGH AND VORT
MAX. 850MB WINDS AROUND 50KT WILL BRING IN PLENTIFUL MOISTURE...AND
PERHAPS SOME INSTABILITY. WILL GO CATEGORICAL POPS THIS EVENING ALL
AREAS AND MENTION ISOLATED THUNDER.

AS THE FIRST UPPER WAVE PASSES OFF TO THE NORTHEAST BY LATE EVENING
RAIN WILL DIMINISH TO SCATTERED SHOWERS. HOWEVER...AS A COLD FRONT
AND OTHER UPPER TROUGH APPROACH THE AREA LATE TONIGHT...RAIN WILL
ONCE AGAIN BECOME MORE WIDESPREAD. WENT LIKELY POPS ONCE AGAIN
ACROSS THE WEST AFTER 09Z WITH HIGH CHANCES EAST.

TEMPERATURES WILL BE TRICKY WITH RAIN ACROSS THE AREA AS WELL
CENTRAL INDIANA MOVING MORE INTO THE WARM SECTOR AHEAD OF THE COLD
FRONT TONIGHT. READINGS MAY RISE SOME OVERNIGHT BEFORE STARTING TO
FALL LATE WEST AS THE COLD FRONT MOVES IN.

FOR NOW WENT NEAR OR JUST ABOVE MOS FOR LOW TEMPERATURES...BUT THESE
WILL LIKELY HAVE TO BE ADJUSTED AS THE SITUATION UNFOLDS.

&&

.SHORT TERM.../MONDAY THROUGH WEDNESDAY/
ISSUED AT 307 PM EST SUN NOV 23 2014

FOCUS IS ON WINDY CONDITIONS MONDAY AND ON ANY CHANCES FOR RAIN
THROUGH THE PERIOD. FOR THE MOST PART MODELS ARE CLOSE ENOUGH THAT A
BLEND CAN BE USED...BUT GFS LOOKS TOO FAST WITH WEDNESDAY/S SYSTEM.
RELIED LESS ON GFS THEN.

LOOKS LIKE THERE WILL BE SOME DECENT FORCING WITH THE COLD
FRONT...AND MOST MODELS ARE PUTTING OUT RAINFALL WITH THE FRONT AS
IT PASSES THROUGH. THUS WENT LIKELY POPS MOST AREAS MONDAY MORNING.
AS FRONT PASSES BY FORCING WILL WEAKEN SO LOWERED POPS AFTER IT GOES
BY.

FORCING WITH THE UPPER TROUGH WILL STILL BE CLOSE ENOUGH TO THE AREA
TO GO CHANCE POPS ACROSS THE NORTHWEST FORECAST AREA MONDAY
AFTERNOON AND SLIGHT CHANCE REMAINDER OF NORTH HALF. AS COLDER AIR
MOVES IN DURING THE DAY PRECIPITATION WILL MIX WITH AND CHANGE TO
SNOW. NOT EXPECTING ANY ACCUMULATION AT THIS TIME.

MAIN STORY MONDAY WILL BE THE WINDS. STRONG WINDS WILL BE NOT TOO
FAR OFF THE SURFACE...WITH 850MB WINDS OVER 50KT AND 925MB WINDS
OVER 40KT. SURFACE PRESSURE GRADIENT WILL BE TIGHT ACROSS THE AREA.
THESE PLUS COLD ADVECTION HELPING MIX THE WINDS DOWN WILL CREATE
WINDY CONDITIONS ACROSS THE ENTIRE AREA. SREF FORECASTS SHOW HIGH
CHANCES OF SUSTAINED WINDS OVER 25KT ACROSS PARTS OF THE AREA MONDAY
AS WELL.

STRONGEST WINDS LOOK TO BE ACROSS THE NORTHEAST FORECAST AREA IN THE
TIGHTER PRESSURE GRADIENT WHERE WIND GUSTS AROUND 45 MPH WILL BE
POSSIBLE. ELSEWHERE WINDS COULD GUST AROUND 40 MPH AND WILL BE CLOSE
TO ADVISORY CRITERIA. /GFS SHOWS EVEN HIGHER GUSTS POSSIBLE...WITH
GUSTS MORE WIDESPREAD THAN THE NAM/. AFTER COLLABORATING WITH
SURROUNDING OFFICES DECIDED TO GO WIND ADVISORY ACROSS ALL OF THE
AREA.

FOR MOST AREAS WENT 12Z-00Z...BUT IN THE NORTHEAST WHERE PRESSURE
GRADIENT WILL ARRIVE LATER AND REMAIN A FACTOR LONGER...WENT 14Z-03Z.

UPPER TROUGH COULD STILL BRING A FEW SNOW SHOWERS TO NORTHERN AREAS
MONDAY NIGHT. HIGH PRESSURE WILL BRING DRY CONDITIONS TO THE AREA
TUESDAY INTO WEDNESDAY MORNING.

ANOTHER FRONT WILL BRING CHANCES FOR PRECIPITATION WEDNESDAY
AFTERNOON. UNCERTAINTIES IN TIMING AND FORCING LEADS TO ONLY LOW
POPS FOR NOW. BASED ON EXPECTED TEMPERATURES WENT MIXED RAIN AND
SNOW MOST AREAS.

LOOKING AT TEMPERATURES...ON MONDAY READINGS WILL FALL DURING THE
DAY. A MODEL BLEND LOOKS GOOD FOR LOWS MONDAY NIGHT. MAV MOS LOOKS
TOO WARM ON TUESDAY WITH EXPECTED CLOUD COVER. WENT CLOSER TO A
MODEL BLEND.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
ISSUED AT 224 PM EST SUN NOV 23 2014

A BROAD UPPER TROUGH MAY BRING MIX PRECIP CHANCES TO THE AREA AT THE
BEGINNING OF THE PERIOD AND THEN ZONAL FLOW WILL COMMENCE THROUGH
THE FIRST HALF OF NEXT WEEKEND. AN UPPER LEVEL DISTURBANCE IS NEXT
DUE TO IMPACT THE REGION SATURDAY NIGHT INTO SUNDAY WITH CHANCES FOR
RAIN/RAIN AND SNOW MIX/AND SNOW. ACCUMULATIONS APPEAR VERY LIGHT AT
THIS TIME AND THIS IS NOT A LOT OF CONFIDENCE THIS FAR OUT IN THE
EXTENDED SO STUCK WITH 20 PERCENT POPS. SUPERBLEND GUIDANCE
INITIALIZED WELL. ONLY NEED TO MAKE A FEW MINOR TWEAKS.

&&

.AVIATION /DISCUSSION FOR THE 24/03Z TAF UPDATE/...
ISSUED AT 927 PM EST SUN NOV 23 2014

NO CHANGES NECESSARY. PREVIOUS DISCUSSION FOLLOWS.

ISSUED AT 617 PM EST SUN NOV 23 2014

WIDESPREAD IFR THROUGH THE FIRST 12 TO 14 HOURS OF THE TAF
PERIOD...FOLLOWED BY WIDESPREAD MVFR AND THEN SOME IMPROVEMENT TO
BORDERLINE VFR TOMORROW AFTERNOON.

RAPIDLY STRENGTHENING LOW PRESSURE WILL MOVE THROUGH THE REGION
TONIGHT INTO TOMORROW. WIDESPREAD LIGHT TO MODERATE RAIN AND IFR
RESTRICTIONS NOTED AHEAD OF THE LOW...WHICH SHOULD PERSIST THROUGH
THE NIGHT.

COULD SEE SOME GUSTINESS OVERNIGHT AS THE LOW STRENGTHENS...BUT NOT
CONVINCED IT WILL BE PERSISTENT ENOUGH TO GO WITH MORE THAN A STRONG
SUSTAINED WIND. LOW LEVEL WIND SHEAR IS A MORE POTENT THREAT EAST OF
THE SITES WHERE THE LOW LEVEL JET WILL BE FAR MORE PRONOUNCED...AND
AREA VAD WIND PROFILES SUPPORT WINDS BELOW 2KFT NO MORE THAN 30-35KT
AT THIS TIME.

AS THE COLD FRONT PASSES TOMORROW MORNING AND THE SURFACE PRESSURE
GRADIENT TIGHTENS...LOW LEVEL WINDS WILL STRENGTHEN AND COLD
ADVECTION WILL HELP MIX SOME OF THIS DOWN TO THE SURFACE. WIND GUSTS
FROM THE WEST/SOUTHWEST MAY APPROACH AND EVEN OCCASIONALLY EXCEED
40KT AT THE SITES...ESPECIALLY TOMORROW AFTERNOON.

THUNDER WILL BE AT LEAST A MARGINAL THREAT WITH THE RAPID
DEVELOPMENT OF THE LOW...STRONG DYNAMICS...AND AT LEAST A SMALL
AMOUNT OF SHALLOW INSTABILITY...BUT WITH NO CONFIDENCE IN TIMING OR
PLACEMENT OF THE THREAT...CANNOT INCLUDE A MENTION AT THIS TIME.

&&

.IND WATCHES/WARNINGS/ADVISORIES...

WIND ADVISORY FROM 7 AM TO 7 PM EST MONDAY FOR
INZ021-028>030-035>037-039-043>048-051>057-060>065-067>072.

WIND ADVISORY FROM 9 AM TO 10 PM EST MONDAY FOR INZ031-038-
040>042-049.

&&

$$

SYNOPSIS...50
NEAR TERM...50
SHORT TERM...50
LONG TERM...SMF
AVIATION...NIELD

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