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 312027
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
426 PM EDT SUN AUG 31 2014

.UPDATE...
AVIATION SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 328 PM EDT SUN AUG 31 2014

SEVERAL DIFFERENT DISTURBANCES THROUGH THE FORECAST PERIOD WILL
RESULT IN RAIN SHOWER AND THUNDERSTORM CHANCES. FIRST...ISOLATED
SHOWERS AND THUNDERSTORMS WILL PERSIST INTO TONIGHT IN THE WAKE OF
AN UPPER DISTURBANCE. THE MAIN FOCUS WILL BE ON TOMORROW THOUGH AS
AN UPPER TROUGH AND COLD FRONT BRING A THREAT FOR SEVERE WEATHER.
IN THE EXTENDED...WARM AND HUMID CONDITIONS WILL RETURN LATE IN
THE WEEK AS A WARM FRONT ENTERS CENTRAL INDIANA. FURTHER OUT...A
COLD FRONT WILL DROP TEMPS CONSIDERABLY.


&&


.NEAR TERM /TONIGHT/...

ISSUED AT 328 PM EDT SUN AUG 31 2014

ISOLATED SHOWERS WITH SOME EMBEDDED THUNDER ARE PERSISTING OVER
THE SOUTHEAST PORTIONS OF THE FORECAST AREA AT THIS TIME. DRIER
AIR WILL FILTER IN FROM THE WEST THROUGH THE COURSE OF THE
NIGHT...BUT HELD ONTO SLIGHT CHANCE POPS OVER THE SOUTHEAST
QUADRANT THROUGH THE NIGHT WITH AMPLE MOISTURE IN THE LOWER
LEVELS.

PATCHY FOG COULD ALSO BE A THREAT LATE TONIGHT...BUT CONFIDENCE IS
NOT HIGH ENOUGH TO MENTION IN GRIDS AT THIS TIME.

TEMPS...OVERNIGHT LOWS WILL BE RATHER WARM WITH READINGS IN THE
UPPER 60S. THE NAM IS TRENDING SLIGHTLY WARMER THAN THE GFS...SO A
BLEND OF THE 2 MODELS SEEMED BEST.


&&

.SHORT TERM /TOMORROW THROUGH WEDNESDAY/...

ISSUED AT 328 PM EDT SUN AUG 31 2014

THE MAIN FOCUS OF THE SHORT TERM PERIOD IS THE SEVERE THREAT
TOMORROW.

SPC HAS MOST OF CENTRAL INDIANA UNDER A SLIGHT RISK FOR SEVERE
WEATHER ON DAY 2 AS AN UPPER TROUGH ENTERS THE FORECAST AREA JUST
AHEAD OF A SURFACE COLD FRONT. THE BEST DYNAMICS WITH THIS SETUP
WILL BE OVER WISCONSIN...WHERE THE UPPER TROUGH WILL BE STRONGEST.
HOWEVER...A VERY UNSTABLE ENVIRONMENT WILL BE IN PLACE ACROSS
ILLINOIS AND INDIANA AS SOUTHWEST WINDS BRING TEMPS INTO THE MID
TO UPPER 80S WITH DEWPOINTS SOARING INTO THE LOW 70S BY TOMORROW
AFTERNOON. MUCAPES WILL BE AS HIGH AS 2500 J/KG WITH 0-6KM BULK
SHEAR OF 30 TO 50 KTS.

CONVECTION WILL INITIATE AROUND LATE AFTERNOON TOMORROW OVER THE
NORTHWEST COUNTIES...PROPAGATING TO THE SOUTH AND EAST THROUGH THE
NIGHT. THE BULK OF THE ACTIVITY WILL MOVE THROUGH CENTRAL INDIANA
DURING THE TUE 06Z-15Z TIME FRAME. CONFIDENCE WAS HIGH ENOUGH TO
GO WITH DEFINITE POPS OVER THE AREA AT TIMES.

ACTIVITY WILL DIMINISH BY TUESDAY AFTERNOON...BUT HELD ONTO SLIGHT
CHANCE POPS OVER THE SOUTHERN COUNTIES INTO TUESDAY NIGHT DUE TO
LINGERING MOISTURE AND A VERY SUBTLE SHORT WAVE IN THE UPPER FLOW.

HIGH PRESSURE AND ZONAL FLOW ALOFT WILL PROVIDE DRY CONDITIONS ON
WEDNESDAY. MEANWHILE...TEMPS WILL FALL INTO THE LOW TO MID 80S ON
WEDNESDAY AFTER A FEW HOT DAYS ON MONDAY AND TUESDAY. A MODEL
BLEND HANDLED THIS BEST.


&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...

ISSUED AT 328 PM EDT SUN AUG 31 2014

WARM AND HUMID WEATHER FOR THE SECOND HALF OF THE WORK WEEK WILL
TRANSITION TO COOLER AND DRIER WEATHER IN THE WAKE OF A STRONG COLD
FRONT BY LATE WEEKEND.

BROAD RIDGING ALOFT WILL RETURN FOR MUCH OF THE MIDWEST AND OHIO
VALLEY TO START THE EXTENDED PERIOD AS GOOD MODEL CONSENSUS NOW
EXISTS WITH THE UPPER HIGH RETROGRADING WEST INTO THE LOWER
MISSISSIPPI VALLEY FOR LATE WEEK. SMALL CHANCES FOR THUNDERSTORMS
WILL EXIST FOR THURSDAY AS A WARM FRONT LIFTS THROUGH THE REGION BUT
OTHERWISE...A VERY WARM AND HUMID AIRMASS WILL MAKE ITS REAPPEARANCE
FOR LATE WEEK WITH HIGHS NEAR 90.

STRONG LOW PRESSURE WILL TRACK FROM THE NORTHERN PLAINS INTO ONTARIO
BY FRIDAY...WITH A TRAILING COLD FRONT MOVING INTO THE LOWER GREAT
LAKES. THE FRONT IS POISED TO SLOWLY CROSS THE REGION LATE FRIDAY
INTO SATURDAY AS IT RUNS INTO THE RIDGE TO OUR SOUTH...AND WILL
PROVIDE THE BEST CONVECTIVE CHANCES DURING THE EXTENDED. THE PASSAGE
OF THE COLD FRONT WILL BRING A NOTICEABLE CHANGE IN AIRMASS AS LARGE
HIGH PRESSURE WILL DIVE SOUTH INTO THE GREAT LAKES IN ITS WAKE.
INCREASING CONFIDENCE IN A DRIER AND COOLER SECOND HALF OF NEXT
WEEKEND...WITH HIGHS SUNDAY QUITE POSSIBLY HOLDING IN THE LOW AND
MID 70S WITH STRONG COLD ADVECTION BRINGING 850MB TEMPS BELOW 10C.



&&


.AVIATION /DISCUSSION FOR 312100Z KIND TAF UPDATE/...
ISSUED AT 426 PM EDT SUN AUG 31 2014

MINOR TWEAKS MADE TO KIND TAF TO BETTER MATCH CURRENT CONDITIONS.
NO OTHER CHANGES ARE NEEDED AT THIS TIME.

PREVIOUS AVIATION DISCUSSION FOLLOWS...
MVFR AND LOWER CEILINGS LIKELY TO PLAGUE THE TERMINALS THROUGHOUT
MUCH OF THE FORECAST PERIOD.

DRIER AIR STRUGGLING TO ADVECT INTO THE FORECAST AREA EARLY THIS
AFTERNOON AS MOISTURE HAS BEEN SLOW TO DEPART TO THE EAST.
WIDESPREAD CEILINGS AT OR BELOW 2KFT CONTINUE ALTHOUGH STARTING TO
SEE SOME BREAKS IN THE DECK. WEAK MID LEVEL VORT CONTRIBUTING TO
REDEVELOPMENT OF ISOLATED SHOWERS AS WELL...WHICH MAY PERSIST AT
KBMG AND KIND FOR THE NEXT FEW HOURS. EVENTUALLY THOUGH...EXPECT
CEILINGS TO LIFT AND MAY EVEN SCATTER FOR A BRIEF PERIOD INTO THE
EVENING AS WEAK HIGH PRESSURE BUILDS IN FROM THE WEST.

ANY SCATTERING OF THE DECK WILL BE SHORT LIVED HOWEVER AS MODEL
SOUNDINGS AND LOW LEVEL RH PROGS BOTH HIGHLIGHT A REDEVELOPMENT OF
LOW STRATUS AND POSSIBLY SOME FOG AS WELL OVERNIGHT WITH MOISTURE
BECOMING TRAPPED UNDER A SHALLOW INVERSION. EXPECT IFR AND LOWER
CEILINGS TO DEVELOP AT ALL SITES PRIOR TO DAYBREAK. LOW CLOUDS
WILL LIFT OUT MORE QUICKLY MONDAY MORNING AS LOW LEVEL MIXING
COMMENCES WITH THE ARRIVAL OF A STRONGER 850MB JET INTO CENTRAL
INDIANA. EXPECT SOUTHWEST WINDS AT 10-15KTS WITH GUSTS INTO THE
LOW 20S BY MIDDAY. CONVECTIVE POTENTIAL WILL INCREASE THROUGH THE
AFTERNOON AS WELL WITH THE APPROACH OF A FRONTAL BOUNDARY.


&&

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

$$

SYNOPSIS...TDUD
NEAR TERM...TDUD
SHORT TERM...TDUD
LONG TERM....RYAN
AVIATION...RYAN/JH

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS









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