Flash Flooding and Flooding in Indiana, June 20, 2011

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1254 AM EDT MON JUN 20 2011

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

&&

.SYNOPSIS...
AN ACTIVE...CHANGEABLE WEATHER PATTERN IS EXPECTED THROUGH THURSDAY.
A LINGERING WARM FRONT  OVER ILLINOIS AND INDIANA WILL CONTINUE
TO PROVIDE A FOCUS FOR SHOWERS AND STORMS THROUGH EARLY THIS WEEK.
ON MONDAY...THE FRONT IS EXPECTED TO PUSH NORTH AS LOW PRESSURE
DEEPENS IN THE NORTHERN PLAINS. THIS WILL ALLOW MUCH WARMER AND
VERY HUMID AIR TO SURGE INTO CENTRAL INDIANA FROM THE SOUTHWEST AND
PROVIDE AMPLE MOISTURE FOR THUNDERSTORM DEVELOPMENT. HIGH
TEMPERATURES ON MONDAY AND TUESDAY WILL REACH THE UPPER 80S TO AROUND
90 AT MANY SPOTS...WITH HIGH HUMIDITY.

A COLD FRONT IS THEN EXPECTED TO PUSH ACROSS THE REGION ON
WEDNESDAY AND THURSDAY...BRINGING CHANCES FOR MORE SHOWERS AND
STORMS. HIGH PRESSURE IS EXPECTED TO BUILD IN ACROSS INDIANA ON
FRIDAY THROUGH SUNDAY...BRINGING A RETURN TO DRY AND COOLER WEATHER.

&&

.NEAR TERM /REST OF TONIGHT/...

EARLIER MCV MAINLY STAYED SOUTH OF FORECAST AREA...AND RADAR HAS
BEEN CALM EVER SINCE. REDUCED POPS OVER THE NORTHERN PORTIONS OF
CENTRAL INDIANA AFTER MIDNIGHT. HOWEVER...DID NOT WANT TO ENTIRELY
PULL MENTION OF THUNDERSTORMS BECAUSE OF ACTIVITY BLOWING UP OVER
EASTERN KANSAS...AS WELL AS SOUTHERN ILLINOIS. AS A RESULT...THERE
IS STILL THE POSSIBILITY OF CONVECTION ACROSS THE FAR SOUTHERN
PORTIONS OF CENTRAL INDIANA LATE TONIGHT.

TEMPS...DO NOT SEE ANY REASON WHY THE SAME TREND THE LAST FEW NIGHTS
WOULDN/T PREVAIL TONIGHT. SO...MADE NO CHANGES TO CURRENT OVERNIGHT
LOWS...STILL EXPECTING MID TO UPPER 60S.

UPDATED GRIDS HAVE BEEN SENT.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...

GFS AND NAM ARE IN PRETTY GOOD AGREEMENT WITH THE OVERALL PATTERN
AND WILL USE A BLEND. WARM FRONT IS EXPECTED TO SURGE NORTHWARD ON
MONDAY AFTERNOON AS THE NEXT SHORT WAVE IS EXPECTED TO ARRIVE. GFS
310K ISENTROPIC SURFACE SHOWS DECENT UPGLIDE BY 18Z WITH SPECIFIC
HUMIDITY/S IN EXCESS OF 8 G/KG. THUS WE ARE DEALING WITH A VERY
MOIST AIR MASS. FURTHERMORE FORECAST SOUNDINGS SHOW A NEARLY
SATURATED COLUMN WITH HIGH CAPE AND LI/S LESS THAN -5. GIVEN THIS
INSTABILITY AND THE ACTIVE PATTERN WITH THE LINGERING SURFACE
BOUNDARY WILL CONTINUE TO KEEP HIGHER POPS IN THE
FORECAST...FOCUSING BEST CHCS NEAR THE FRONT. GIVEN THE EXPECTED
CLOUDS AND PRECIPITATION WILL LEAN COOLER THAN MAVMOS...USING A
BLEND.

STRONGER RIDGING ALOFT IS EXPECTED TO BUILD ACROSS CENTRAL INDIANA
ON MONDAY NIGHT. FORECAST SOUNDINGS SHOW ATMOSPHERE BECOMING
CAPPED IN THE WARM SECTOR AS 700MB TEMPS SURGE IN EXCESS OF
10C...AND CONVECTIVE TEMPERATURES ARE TOO HIGH TO REACH. THUS WILL
AIM FOR PTCLDY BUT WARM CONDITIONS.

AS THE UPPER RIDGE SLIDES EAST ON TUESDAY AND TUESDAY NIGHT
FAVORABLE INSTABILITY WILL ONCE AGAIN EXIST AS FORECAST SOUNDINGS
SHOW CAPE IN EXCESS OF 3000 J/KG AND LI/S OF LESS THAN -8. THUS
WILL ONCE AGAIN KEEP CHANCES FOR SHOWERS AND STORMS DURING THE
AFTERNOON AND EVENING HOURS. GIVEN THE VERY WARM AIR MASS OVER THE
AREA WILL TREND HIGHS AND LOWS TOWARD THE WARMER MAVMOS VALUES
WHICH LOOK VERY REASONABLE.

&&

.LONG TERM /WEDNESDAY THROUGH SUNDAY/...

ECMWF AND GFS ARE IN PRETTY GOOD AGREEMENT WITH THE OVERALL
PATTERN AND WILL USE A BLEND. WARM AND HUMID AIR MASS LOOKS TO BE
IN PLACE AHEAD OF THE COLD FRONT THAT WILL PASS ON
WEDNESDAY...THUS WILL KEEP TSRA MENTIONS AT THAT TIME AND CONTINUE
CHANCES INTO THURSDAY. BROAD CYCLONIC FLOW WILL REMAIN ON
THURSDAY WITH COOLER AIR ALOFT THAT COULD RESULT IN SOME
INSTABILITY SHOWERS.

COOLER AND DRIER NORTHERLY FLOW WILL BUILD ACROSS INDIANA FOR
FRIDAY THROUGH NEXT SUNDAY AS LARGE CANADIAN HIGH PRESSURES SLOWLY
DIVES SOUTH THROUGH THE WEEKEND AS RIDGING BUILDS ALOFT. MEXMOS
POPS LOOK TOO HIGH AS THEY ARE LEANING TOWARD CLIMATOLOGY TOO MUCH
FOR THIS TIME OF YEAR GIVEN THIS PATTERN. THUS WILL KEEP A DRY
FORECAST FOR NOW FOR NEXT WEEKEND.

&&

.AVIATION.../DISCUSSION FOR THE 200600Z TAFS/...

ISOLATED CONVECTION IS POSSIBLE NEAR THE SOUTHERN SITES BEFORE
12Z...BUT BETTER CHANCES FOR CONVECTION WILL COME AFTER 12Z AS A
WARM FRONT MOVES NORTH. BY 18Z OR SO CHANCES WILL BEGIN TO DIMINISH
AS UPPER RIDGING BUILDS IN. FOR NOW WILL USE A COMBINATION OF CB AND
VCTS TO HIGHLIGHT THREAT. STORM THREAT SHOULD EB GONE BY 00Z.

OTHER PROBLEM IS FOG TONIGHT. GROUND FOG IS LIKELY WITH LIGHT WINDS
AND PLENTIFUL LOW LEVEL MOISTURE. FOR NOW WILL GO WITH MVFR
CONDITIONS AND MENTION AREAS OF DENSE FOG NEARBY WITH BCFG. FOG WILL
BURN OFF QUICKLY AFTER SUNRISE.

WINDS WILL HAVE A SOUTHERLY COMPONENT AND LESS THAN 15 KNOTS THROUGH
THE PERIOD.

&&

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

&&

SYNOPSIS...PUMA
NEAR TERM...TDUD
SHORT TERM...PUMA
LONG TERM....PUMA
AVIATION...MK/50

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
933 PM EDT SUN JUN 19 2011

INZ021-028>031-035>049-057-210145-
CARROLL-WARREN-TIPPECANOE-CLINTON-HOWARD-FOUNTAIN-MONTGOMERY-
BOONE-TIPTON-HAMILTON-MADISON-DELAWARE-RANDOLPH-VERMILLION-PARKE-
PUTNAM-HENDRICKS-MARION-HANCOCK-HENRY-RUSH-
933 PM EDT SUN JUN 19 2011

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL INDIANA.

.DAY ONE...TONIGHT.

THERE IS A CHANCE OF THUNDERSTORMS ACROSS THE AREA FOR TONIGHT.
THESE STORMS ARE NOT ANTICIPATED TO BECOME SEVERE...HOWEVER
LIGHTNING IS A HAZARD WITH ANY THUNDERSTORM.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY.

THERE IS A CHANCE OF THUNDERSTORMS MONDAY THROUGH WEDNESDAY NIGHT.
THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS MONDAY THROUGH
TUESDAY WITH LARGE HAIL AND DAMAGING WINDS AS THE MAIN THREATS.
LOCALLY HEAVY RAIN IS ALSO POSSIBLE.

.SPOTTER INFORMATION STATEMENT...

SPOTTERS ARE ENCOURAGED TO CALL IN WITH ANY SEVERE WEATHER OR
FLOODING REPORTS TONIGHT AND MONDAY.

&&

MORE INFORMATION...ALONG WITH OTHER WEATHER...HYDROLOGICAL AND
CLIMATE INFORMATION CAN BE FOUND...AT HTTP://WEATHER.GOV/IND (ALL
LOWERCASE)

INZ051>056-060>065-067>072-210145-
VIGO-CLAY-OWEN-MORGAN-JOHNSON-SHELBY-SULLIVAN-GREENE-MONROE-BROWN-
BARTHOLOMEW-DECATUR-KNOX-DAVIESS-MARTIN-LAWRENCE-JACKSON-JENNINGS-
933 PM EDT SUN JUN 19 2011

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL INDIANA.

.DAY ONE...TONIGHT.

THERE IS A CHANCE OF THUNDERSTORMS ACROSS THE AREA FOR TONIGHT.
THESE STORMS ARE NOT ANTICIPATED TO BECOME SEVERE...HOWEVER
LIGHTNING IS A HAZARD WITH ANY THUNDERSTORM.

LOW LAND FLOODING WILL OCCUR ALONG PORTIONS OF THE WABASH AND
LOWER WHITE RIVER. SEE LATEST FLOOD STATEMENTS FOR MORE DETAIL.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY.

THERE IS A CHANCE OF THUNDERSTORMS MONDAY THROUGH WEDNESDAY NIGHT.
THERE IS A SLIGHT RISK STORMS ON MONDAY AND TUESDAY MAY BE SEVERE WITH
LARGE HAIL AND DAMAGING WINDS AS THE MAIN THREATS. LOCALLY HEAVY
RAIN IS ALSO POSSIBLE.

LOW LAND FLOODING MAY OCCUR ALONG PORTIONS OF THE WABASH AND
LOWER WHITE RIVER THROUGH EARLY THIS WEEK. SEE LATEST FLOOD
STATEMENTS FOR MORE DETAILS.

.SPOTTER INFORMATION STATEMENT...

SPOTTERS ARE ENCOURAGED TO CALL IN WITH ANY SEVERE WEATHER OR
FLOODING REPORTS TONIGHT AND MONDAY.

&&

MORE INFORMATION...ALONG WITH OTHER WEATHER...HYDROLOGICAL AND
CLIMATE INFORMATION CAN BE FOUND...AT HTTP://WEATHER.GOV/IND (ALL
LOWERCASE)