Area Forecast Discussion
Issued by NWS Indianapolis, IN

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000
FXUS63 KIND 240451
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1151 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 /OVERNIGHT/...
ISSUED AT 959 PM EST SUN NOV 23 2014

DUAL AREAS OF LOW PRESSURE CURRENTLY IN THE PROCESS OF COALESCING
ACROSS CENTRAL ILLINOIS AND INTENSIFYING. A WARM FRONT EXTENDS
SOUTHEAST FROM THE DOUBLE BARRELED LOW INTO THE SOUTHERN
APPALACHIANS WITH A LARGE AREA OF MODERATE TO OCCASIONALLY HEAVY
RAINFALL ENCOMPASSING MUCH OF THE FORECAST AREA NORTH OF THE
FRONT. TEMPS WERE IN THE LOWER AND MIDDLE 50S AS OF 0230Z.

FORECAST IS IN REALLY GOOD SHAPE...WITH JUST SOME MINOR
ADJUSTMENTS FOR THE REST OF THE OVERNIGHT. INITIAL POCKET OF DRY
AIR LIFTING UP THROUGH EASTERN COUNTIES RIGHT NOW WITH THE MORE
EXPANSIVE DRY SLOT SOUTH OF THE WARM FRONT IN THE LOWER OHIO
VALLEY. HEAVIEST AREA OF RAIN MOVING NORTH OUT OF THE INDY METRO
AREA AND WILL LIFT NORTH OUT OF THE FORECAST AREA BY 06Z. MANY
LOCATIONS ACROSS CENTRAL INDIANA ALREADY AROUND 1.50 INCHES FOR
THE DAY.

WRF AND HRRR BOTH HAVE A NICE HANDLE ON THE RAINFALL COVERAGE
WITH A 3-4 HOUR DRY SLOT EXPANDING ACROSS THE FORECAST AREA FROM
THE BETWEEN 05-10Z AS THE WARM FRONT LIFTS NORTH. WILL KEEP LOWER
POPS DURING THIS TIMEFRAME...THEN RAMP THEM BACK UP TOWARDS
DAYBREAK AS THE CONVECTION OVER SOUTHERN MISSOURI ARRIVES AHEAD OF
THE COLD FRONT. HAVE BACKED OFF ON ISOLATED THUNDER TO LATE
TONIGHT AND EARLY MONDAY MORNING AS THE CONVECTION ALONG THE COLD
FRONT TRACKS THROUGH THE AREA.

TEMPS SHOULD WARM A COUPLE MORE DEGREES OR REMAIN STEADY OVER THE
NEXT SEVERAL HOURS BEFORE BEGINNING TO SLIP BACK TOWARDS DAYBREAK
WITH THE ARRIVAL OF THE COLD FRONT. WINDS WILL BECOME GUSTY
OVERNIGHT AS WELL AS ALREADY SEEING OBS WITH GUSTS PUSHING 30MPH
IN WESTERN KENTUCKY.

ZONE AND GRID UPDATES OUT.

&&

.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 24/06Z TAFS/...
ISSUED AT 1151 PM EST SUN NOV 23 2014

MVFR OR WORSE CONDITIONS TO PERSIST THROUGH AT LEAST THE FIRST 10-12
HOURS OF THE PERIOD.

RAPIDLY STRENGTHENING LOW PRESSURE MOVING THROUGH THE REGION TONIGHT
INTO TOMORROW. DRY PUNCH MOVING INTO THE AREA BUT ADDITIONAL SHOWERS
LIKELY AT TIMES LATER IN THE NIGHT INTO EARLY MORNING.

COULD SEE SOME GUSTINESS OVERNIGHT AS THE LOW STRENGTHENS. 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...AND
GUSTINESS IMPLIES SHEAR ANYWAY.

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...RYAN
SHORT TERM...50
LONG TERM...SMF
AVIATION...NIELD

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