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 240652
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
252 AM EDT FRI APR 24 2015

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

&&

.SYNOPSIS...
ISSUED AT 300 PM EDT THU APR 23 2015

STRONG HIGH PRESSURE WILL RESULT IN DRY AND COOL WEATHER AGAIN
TONIGHT AND FRIDAY. AS A RESULT...A FREEZE WARNING WILL BE IN EFFECT
OVERNIGHT TONIGHT THROUGH 9 AM FRIDAY FROM INDIANAPOLIS AND NORTH.
MEANWHILE...A FROST ADVISORY WILL BE IN EFFECT SOUTH OF INDIANAPOLIS
FOR THE SAME TIME.

THE REST OF THE WEEKEND...SAVE SUNDAY...WILL BE SHOWERY AS A LOW
PRESSURE SYSTEM TRACKS SOUTHEAST ACROSS THE OHIO VALLEY SATURDAY
NIGHT. THERE COULD ALSO BE A FEW THUNDERSTORMS FRIDAY NIGHT AND
SATURDAY ASSOCIATED WITH THIS SYSTEM. AFTER THAT...HIGH PRESSURE
WILL PROVIDE DRY AND COOL WEATHER TO THE AREA THROUGH MUCH OF THE
REST OF NEXT WEEK. HOWEVER...A SOUTHERN SYSTEM COULD BRING A FEW
SHOWERS TO THE AREA MIDWEEK.

&&

.NEAR TERM /TONIGHT THROUGH 9 AM FRIDAY/...
ISSUED AT 918 PM EDT THU APR 23 2015

CURRENT FORECAST LOOKS IN GOOD SHAPE AT THIS TIME...WITH ONLY MINOR
ADJUSTMENTS MADE. WILL UPGRADE GREENE COUNTY TO A FREEZE WARNING
GIVEN EXPECTED LOW TEMPERATURES BELOW FREEZING IN THAT AREA.

PREVIOUS DISCUSSION FOLLOWS.

TEMPERATURES WILL BE THE MAIN ISSUE TONIGHT AS STRONG HIGH PRESSURE
AND LIGHT TO CALM WINDS SHOULD BRING A FREEZE AND WIDESPREAD FROST
TO MOST AREAS TONIGHT PER 12Z MOS AND 00Z ENSEMBLE MOS. THE
EXCEPTION WILL BE OUR FAR SOUTHWESTERN COUNTIES AND THE CITY OF
INDIANAPOLIS...WITH ITS URBAN HEAT ISLAND EFFECT. THESE AREAS SHOULD
SEE MORE LIKE MID 30S FOR LOWS. WILL UPGRADE TO A FREEZE WARNING FOR
ALL BUT KNOX...SULLIVAN...DAVIESS...MARTIN AND GREENE THROUGH 9 AM
FRIDAY. OTHERWISE...WILL LEAVE THE FROST ADVISORY IN EFFECT.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...

ISSUED AT 300 PM EDT THU APR 23 2015

THE MAIN FOCUS FOR THE SHORT TERM WILL BE TIMING AND COVERAGE OF
SHOWERS ACROSS THE AREA AS WELL AS THUNDER POTENTIAL AND TIMING.

MODELS AGREE THAT A SOUTHWEST UPPER WAVE WILL INTENSIFY AND BECOME A
CLOSED LOW OVER NORTHERN MISSOURI FRIDAY NIGHT. THIS WILL SPIN UP A
SURFACE LOW FRIDAY NIGHT. HOWEVER...THERE ARE MODEL TO MODEL AND RUN
TO RUN DIFFERENCES REGARDING THIS FEATURE.  THE MODELS DIFFER A BIT
IN STRENGTH BUT MORE SO ON PLACEMENT. OVERALL...THE 00Z ECMWF AND
CANADIAN AND 06Z GFS MATCH UP CLOSER TO THE TRUSTIER ENSEMBLE MEANS.
A BLEND THEREOF WOULD SUGGEST THE SURFACE LOW WOULD BE MODERATELY
STRONG AND BE OVER NORTHWESTERN MISSOURI 12Z SATURDAY...SOUTH
CENTRAL ILLINOIS 00Z SUNDAY AND SHEAR OUT OVER SOUTHEASTERN KENTUCKY
BY 12Z SUNDAY BEFORE BECOMING GOBBLED UP BY AN EAST COAST SYSTEM.

FRIDAY SHOULD START OFF FROSTY WITH THE SURFACE HIGH PRESSURE RIDGE
OVER EASTERN INDIANA. THE RIDGE WILL THEN SLIDE EAST OVER THE
EASTERN GREAT LAKES AND BLUE RIDGE MOUNTAINS BY FRIDAY EVENING. THIS
WILL RESULT IN A LIGHT SOUTHERLY FLOW ACROSS CENTRAL INDIANA. THAT
AS WELL AS A DRY COLUMN SHOULD ALLOW TEMPERATURES TO REBOUND QUICKLY
DURING THE MORNING AND EARLY AFTERNOON. THEN...MODEL RH TIME
SECTIONS WERE SHOWING INCREASING MID LEVEL MOISTURE ACROSS THE AREA
FROM SOUTHWEST TO NORTHEAST DURING THE AFTERNOON AHEAD OF AN
APPROACHING UPPER RIDGE AND DEVELOPING LOW PRESSURE SYSTEM OVER THE
HIGH PLAINS. THIS SHOULD BRING INCREASING AFTERNOON CLOUDINESS AND
SLOW THE WARMING WITH SLIGHTLY BELOW NORMAL 12Z MOS HIGHS IN THE
LOWER AND MID 60S LOOKING GOOD. WOULD NOT RULE OUT A FEW SHOWERS
SOUTHWEST TOWARD 00Z SATURDAY AS ISENTROPIC LIFT INCREASES...BUT
WITH THE LOWER LEVELS BEING AS DRY AS THEY ARE...HELD OFF POPS UNTIL
FRIDAY NIGHT WHEN ISENTROPIC LIFT AT THE 300K LEVEL RAMP UP EVEN
MORE...AND THE ATMOSPHERE SATURATES DOWN. THE BEST COMBO OF
ISENTROPIC LIFT AND MOISTURE CONTINUE TO LOOK TO BE FROM 06Z TO 18Z
SATURDAY. WILL CONTINUE WITH LIKELY TO CAT POPS THEN SANDWICHED BY
CHANCE POPS FRIDAY EVENING AND SATURDAY NIGHT. AS THE LOW MOVES OFF
TO THE SOUTHEAST AND HIGH PRESSURE BUILDS IN FROM THE
NORTHWEST...CLOUDS SHOULD BE DECREASING FROM NORTHWEST TO SOUTHEAST
SUNDAY AFTERNOON.

LOOKING AT INSTABILITY PROGS...COULD SEE SOME THUNDER OVERNIGHT
FRIDAY NIGHT AND SATURDAY...ESPECIALLY OVER OUR SOUTHWESTERN
COUNTIES.

STAYED PRETTY CLOSE TO A MOS BLEND FOR TEMPERATURES AS WARM
ADVECTION AND OVERCAST SKIES/RAIN WILL BATTLE IT OUT.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...

ISSUED AT 244 AM EDT FRI APR 24 2015

DRY WEATHER IS EXPECTED DURING THIS PERIOD AND THE GFS AND ECMWF
STRONG LOW PRESSURE OFF THE EAST COAST OF THE UNITED STATES
ALOFT...PROVIDING COOL NORTHWEST FLOW FOR THE OHIO VALLEY. GULF
MOISTURE REMAINS BLOCKED OFF FOR MUCH OF THIS PERIOD AS A WEAK LOW
LOOKS TO MOVE THROUGH THE DEEP SOUTH. THIS WILL RESULT IN DRY NE
FLOW FOR MUCH OF THE NEXT WORK WEEK. GFS HINTS AT A COLD FRONT
PASSAGE ON THURSDAY WHILE THE ECMWF REMAINS DRY. HAVE TRENDED
GIVEN THE LACK OF GULF MOISTURE EXPECTED WILL TREND FOR THE DRY
FORECAST FOR NOW.

&&

.AVIATION /DISCUSSION FOR THE 24/0600Z TAF ISSUANCE/...
ISSUED AT 100 AM EDT FRI APR 24 2015

VFR CONDITIONS FOR THE NEXT 24 HOURS. BUT WITH LOWERING FLIGHT
CONDITIONS AFTER THAT.

HIGH PRESSURE ACROSS INDIANA WILL MOVE ON TO THE EAST COAST AS LOW
PRESSURE OVER THE ROCKIES MOVES INTO THE CENTRAL PLAINS BY LATE
FRIDAY.

SATELLITE AND MODEL SOUNDINGS INDICATE CLEAR SKIES WILL CONTINUE
THROUGH 15Z FOLLOWED BY INCREASING HIGH CLOUDS ON FRIDAY.  MID
CLOUDS WILL SPREAD IN LATE FRIDAY AND LIGHT SHOWERS POSSIBLE BY THE
END OF THE FORECAST PERIOD.  CEILINGS WILL LOWER FRIDAY NIGHT...THEY
SHOULD REMAIN VFR UNTIL WELL AFTER MIDNIGHT.

LIGHT AND VARIABLE WINDS OVERNIGHT WILL BECOME SOUTH TO SOUTHEAST UP
TO 6 KNOTS ON FRIDAY AND EAST TO SOUTHEAST AROUND 8 KNOTS FRIDAY
NIGHT.


&&

.IND WATCHES/WARNINGS/ADVISORIES...
FREEZE WARNING UNTIL 9 AM EDT THIS MORNING FOR INZ021-028>031-
035>049-051>057-061>065-070>072.

FROST ADVISORY UNTIL 9 AM EDT THIS MORNING FOR INZ060-067>069.

&&

$$

SYNOPSIS...KOCH
NEAR TERM...KOCH/JAS
SHORT TERM...KOCH
LONG TERM....PUMA
AVIATION...JH/JP

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.