See an update to this post.

SPC Day 1 Categorical Outlook, issued 12:23 p.m. EDT. Valid 12:30 p.m. EDT June 27 through 8 a.m. EDT June 28. Green area: general thunderstorms. Yellow area: slight risk of severe weather.

As a result of changing conditions, much of northern Indiana and northwestern Ohio are now at slight risk of severe weather this afternoon and this evening. In an updated Day 1 Convective Outlook issued at 12:23 p.m. EDT, the National Weather Service Storm Prediction Center extended to the east the area of slight risk. As you can see on the map above, the slight risk area (yellow) now includes much of IMO SKYWARN quadrant two, including Allen County, Indiana and its surrounding counties. The only quadrant two counties of which significant portions are not included are Jay County, Indiana and Allen County, Ohio. Also under slight risk: the southern half of Michigan, the northeastern corner of Illinois and the eastern half of Wisconsin.

The above-mentioned slight risk area has a no measurable risk of tornadoes and a 15 percent probability of each the following occurring within 25 miles of a point: thunderstorm winds or wind gusts of 58 mph or greater and one-inch-diameter hail or larger.

The latest outlook indicates that weak to moderate instability and strengthening changes in wind direction and speed with altitude (shear) might contribute to scattered strong and/or severe storm development – including a couple of supercells — today into tonight.

Spotters: Subsequent to the updated convective outlook mentioned above, the northern Indiana NWS offfice issued an updated Hazardous Weather Outlook at 12:50 p.m. that indicates spotter activation might be needed this afternoon. 

See an important update to this post (slight risk extended).

The northwestern quarter of Indiana (see map at left) has a slight risk of severe weather between 8 a.m. EDT today and 8 a.m. EDT tomorrow, according to the updated Day 1 Convective Outlook that the National Weather Service (NWS) Storm Prediction Center (SPC) issued at 8:40 a.m. EDT. The slight risk area includes approximately the western half of the county warning area of the northern Indiana NWS office (most of IMO SKYWARN quadrants three and four). The SPC does not expect severe weather in IMO SKYWARN quadrants one or two, which means no real risk of severe weather in the greater Fort Wayne area.

Northern Indiana is no longer at risk of severe weather today.

At 2:26 p.m., the northern Indiana National Weather Service (NWS) office tweeted the following:

“Good News! Morning rain/clouds has significantly reduced svr wx risk for today Showers & thunderstorms thru evening should remain sub-severe.”

The office issued an updated Hazardous Weather Outlook at12:50 p.m. EDT that indicates SKYWARN storm spotter activation is no longer anticipated today. The office still wants to receive reports of significant flooding.

The NWS Storm Prediction Center issued an updated Day 1 Convective Outlook at 12:26 p.m. EDT. As you can see on the map above, the southern two thirds of Indiana remained at slight risk but Blackford and Jay Counties were the only counties in IMO SKYWARN quadrant two that were still in the slight risk area.

Although the risk of severe storms in the Fort Wayne area has disappeared, the risk heavy rain and flash flood remains, so stay tuned to your favorite source up weather alerts for any warnings that might come out!

URGENT - IMMEDIATE BROADCAST REQUESTED
FLOOD WATCH
NATIONAL WEATHER SERVICE NORTHERN INDIANA
925 AM EDT WED JUN 26 2013

......HEAVY RAINFALL MAY LEAD TO ADDITIONAL FLOODING TODAY INTO
THIS EVENING...

INZ003>009-012>018-020-022>027-032>034-262130-
/O.NEW.KIWX.FF.A.0002.130626T1325Z-130627T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
LA PORTE-ST. JOSEPH IN-ELKHART-LAGRANGE-STEUBEN-NOBLE-DE KALB-
STARKE-PULASKI-MARSHALL-FULTON IN-KOSCIUSKO-WHITLEY-ALLEN IN-
WHITE-CASS IN-MIAMI-WABASH-HUNTINGTON-WELLS-ADAMS-GRANT-BLACKFORD-
JAY-
INCLUDING THE CITIES OF...MICHIGAN CITY...LA PORTE...SOUTH BEND...
MISHAWAKA...NEW CARLISLE...WALKERTON...ELKHART...GOSHEN...
NAPPANEE...LAGRANGE...TOPEKA...SHIPSHEWANA...ANGOLA...FREMONT...
KENDALLVILLE...LIGONIER...ALBION...AUBURN...GARRETT...KNOX...
NORTH JUDSON...BASS LAKE...WINAMAC...FRANCESVILLE...MEDARYVILLE...
PLYMOUTH...BREMEN...CULVER...ROCHESTER...AKRON...WARSAW...
WINONA LAKE...SYRACUSE...MENTONE...COLUMBIA CITY...TRI-LAKES...
SOUTH WHITLEY...FORT WAYNE...NEW HAVEN...MONTICELLO...BROOKSTON...
MONON...LOGANSPORT...ROYAL CENTER...PERU...GRISSOM AFB...MEXICO...
WABASH...NORTH MANCHESTER...HUNTINGTON...ROANOKE...BLUFFTON...
OSSIAN...DECATUR...BERNE...MARION...GAS CITY...UPLAND...
HARTFORD CITY...MONTPELIER...PORTLAND...DUNKIRK
925 AM EDT WED JUN 26 2013 /825 AM CDT WED JUN 26 2013/

...FLASH FLOOD WATCH IN EFFECT THROUGH THIS EVENING...

THE NATIONAL WEATHER SERVICE IN NORTHERN INDIANA HAS ISSUED A

* FLASH FLOOD WATCH FOR A PORTION OF NORTHERN INDIANA... INCLUDING
  THE FOLLOWING AREAS...ADAMS...ALLEN IN...BLACKFORD... CASS
  IN...DE KALB...ELKHART...FULTON IN...GRANT... HUNTINGTON...
  JAY...KOSCIUSKO...LA PORTE...LAGRANGE... MARSHALL...MIAMI...
  NOBLE...PULASKI...ST. JOSEPH IN...STARKE... STEUBEN...WABASH...
  WELLS...WHITE AND WHITLEY.

* THROUGH THIS EVENING

* RAINFALL RATES OF 1 TO 3 INCHES PER HOUR WILL BE POSSIBLE WITH
  THUNDERSTORMS TODAY INTO THIS EVENING. ADDITIONAL LOCALIZED
  RAINFALL TOTALS BETWEEN 3 AND 5 INCHES WILL BE POSSIBLE...WITH
  SOME LOCATIONS NORTH OF THE HIGHWAY 30 CORRIDOR ALREADY
  RECEIVING MORE THAN 4 INCHES OF RAIN AND FLOODING. 

* WHILE MANY RIVERS WILL RESPOND AND BEGIN TO RISE OVER THE NEXT 
  COUPLE OF DAYS FROM THE RAINFALL...SMALLER RIVERS AND CREEKS 
  COULD RAPIDLY FLOOD AND CAUSE ADDITIONAL PROBLEMS. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FLASH FLOOD WATCH MEANS THAT CONDITIONS MAY DEVELOP THAT LEAD
TO FLASH FLOODING. FLASH FLOODING IS A VERY DANGEROUS SITUATION.

YOU SHOULD MONITOR LATER FORECASTS AND BE PREPARED TO TAKE ACTION
SHOULD FLASH FLOOD WARNINGS BE ISSUED.

Probability of damaging thunderstorm winds or wind gusts of 50 knots (58 mph) or higher within 25 miles of a point. (More Info)

See an update to this post.

The entire state of Indiana, including surrounding areas, has a slight risk of severe weather between 8 a.m. EDT today and 8 a.m. EDT tomorrow, according to the Day 1 Convective Outlook that the National Weather Service (NWS) Storm Prediction Center (SPC) issued at 8:45 a.m. EDT. The greatest threats are damaging straight-line thunderstorm winds and hail of up to one inch in diameter. The hail threat is the same throughout the state (15 percent probability of one-inch or larger hail within 25 miles of a point) but the probability of damaging thunderstorm winds or wind gusts of 58 mph or greater is twice as high in the southern half of Indiana (30 percent probability) as in the northern half (15 percent). See the map at left. Widespread heavy rainfall is also likely today, which could lead to flooding.

Michael Lewis, warning coordination meteorologist at the northern Indiana NWS office, sent spotters an email this morning in which he points out that the flooding threat is significant today, especially over northwesten Indiana and southwestern lower Michigan as the thunderstorms continue to form in the same area (one after another, like a train). Later today, meteorologists expect heavier rain to develop further south. Regarding the timing of any severe weather, Lewis writes that the initial threat will last through late morning along and north of US 30. Additional development is likely again this afternoon along and south of US 24.

Whether we get severe weather will depend a lot on how much sunshine we get today. Without the ground heating that sunshine provides, the atmosphere might not become unstable enough to support severe storms.

Nonetheless, the northern Indiana NWS office has indicated via its Hazardous Weather Outlook that SKYWARN storm spotter activation might be needed late this afternoon and this evening. The office also reminded spotters that it will appreciate any reports of significant flooding.

The SPC will update its convective outlook by 12:30 p.m. EDT.

Due to the potential for severe weather today, the northern Indiana National Weather Service office has postponed the NOAA Weather Radio test that it normally conducts on Wednesday mornings. The office will conduct the test on the next good-weather day.

Meanwhile, the Fort Wayne NOAA Weather Radio transmitter continues to operate with a greatly reduced signal, making it impossible for some weather radios to receive the signal.Repair parts are on order but the transmitter might not be back up to full strength for a week or two. It is therefore important to check your weather radio. If it is not picking up the continuous broadcast from the transmitter, that means it will not alert you to incoming severe weather until the transmitter is repaired! Find other ways to receive any watches or warnings that might be issued today or any time between now and when the transmitter is repaired.

The threat for severe weather in the area covered by severe thunderstorm watch number 363 (the one that covers northern Indiana) continues, according to a mesoscale discussion that the National Weather Service Storm Prediction Center issued at 10:20 p.m. EDT. The discussion indicates that a large hail threat might be developing over Illinois as storms regenerate there and then form a train toward the east, creating a heavy rain threat. The discussion indicates that a new watch might be needed over portions of Illinois and Indiana, as watch number 363 is set to expire at 11 p.m. EDT.

URGENT - IMMEDIATE BROADCAST REQUESTED
   SEVERE THUNDERSTORM WATCH NUMBER 363
   NWS STORM PREDICTION CENTER NORMAN OK
   305 PM CDT TUE JUN 25 2013

   THE NWS STORM PREDICTION CENTER HAS ISSUED A

   * SEVERE THUNDERSTORM WATCH FOR PORTIONS OF 
     NORTH CENTRAL ILLINOIS
     NORTHERN INDIANA
     NORTHWEST OHIO

   * EFFECTIVE THIS TUESDAY AFTERNOON AND EVENING FROM 305 PM UNTIL
     1000 PM CDT.

   * PRIMARY THREATS INCLUDE...
     NUMEROUS DAMAGING WIND GUSTS TO 70 MPH LIKELY
     SEVERAL LARGE HAIL EVENTS WITH A FEW VERY LARGE HAIL EVENTS TO 2
       INCHES IN DIAMETER POSSIBLE

   THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 65
   STATUTE MILES NORTH AND SOUTH OF A LINE FROM 40 MILES WEST OF
   PEORIA ILLINOIS TO 25 MILES SOUTHEAST OF FORT WAYNE INDIANA.  FOR
   A COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH
   OUTLINE UPDATE (WOUS64 KWNS WOU3).

   PRECAUTIONARY/PREPAREDNESS ACTIONS...

   REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE
   FAVORABLE FOR SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH
   AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR
   THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS
   AND POSSIBLE WARNINGS. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY
   DO PRODUCE TORNADOES.

   &&

   OTHER WATCH INFORMATION...CONTINUE...WW 361...WW 362...

   DISCUSSION...STORM DEVELOPMENT IS NOW UNDERWAY ACROSS CENTRAL
   ILLINOIS... PERHAPS AIDED BY FORCING ASSOCIATED WITH A SHORT WAVE
   IMPULSE MIGRATING EAST OF THE MIDDLE MISSISSIPPI VALLEY.  IN THE
   PRESENCE OF THERMODYNAMIC PROFILES CHARACTERIZED BY FAIRLY STEEP
   MID-LEVEL LAPSE RATES AND LARGE CAPE...DEEP LAYER WESTERLY FLOW AND
   VERTICAL SHEAR IS SUFFICIENT TO SUPPORT THE UPSCALE GROWTH FROM
   SUPERCELLS TO AN INCREASINGLY ORGANIZED...EASTWARD ADVANCING
   MESOSCALE CONVECTIVE SYSTEM CAPABLE OF PRODUCING DAMAGING WIND
   GUSTS.

SEVERE THUNDERSTORM WATCH 363 IS IN EFFECT UNTIL 1000 PM CDT
   FOR THE FOLLOWING LOCATIONS

   ILC017-019-021-039-041-045-053-057-063-075-091-093-095-099-105-
   107-113-115-123-125-129-137-139-143-147-167-175-179-183-197-203-
   260300-
   /O.NEW.KWNS.SV.A.0363.130625T2005Z-130626T0300Z/

   IL 
   .    ILLINOIS COUNTIES INCLUDED ARE

   CASS                 CHAMPAIGN           CHRISTIAN           
   DE WITT              DOUGLAS             EDGAR               
   FORD                 FULTON              GRUNDY              
   IROQUOIS             KANKAKEE            KENDALL             
   KNOX                 LA SALLE            LIVINGSTON          
   LOGAN                MACON               MARSHALL            
   MASON                MCLEAN              MENARD              
   MORGAN               MOULTRIE            PEORIA              
   PIATT                SANGAMON            STARK               
   TAZEWELL             VERMILION           WILL                
   WOODFORD             


   INC001-003-007-009-011-015-017-023-033-035-039-045-049-053-057-
   059-063-065-067-069-073-075-085-087-089-091-095-097-099-103-107-
   111-113-121-127-131-133-135-141-149-151-157-159-165-169-171-179-
   181-183-260300-
   /O.NEW.KWNS.SV.A.0363.130625T2005Z-130626T0300Z/

   IN 
   .    INDIANA COUNTIES INCLUDED ARE

   ADAMS                ALLEN               BENTON              
   BLACKFORD            BOONE               CARROLL             
   CASS                 CLINTON             DELAWARE            
   DE KALB              ELKHART             FOUNTAIN            
   FULTON               GRANT               HAMILTON            
   HANCOCK              HENDRICKS           HENRY               
   HOWARD               HUNTINGTON          JASPER              
   JAY                  KOSCIUSKO           LAGRANGE            
   LAKE                 LA PORTE            MADISON             
   MARION               MARSHALL            MIAMI               
   MONTGOMERY           NEWTON              NOBLE               
   PARKE                PORTER              PULASKI             
   PUTNAM               RANDOLPH            ST. JOSEPH          
   STARKE               STEUBEN             TIPPECANOE          
   TIPTON               VERMILLION          WABASH              
   WARREN               WELLS               WHITE               
   WHITLEY              


   OHC003-039-051-069-125-137-161-171-260300-
   /O.NEW.KWNS.SV.A.0363.130625T2005Z-130626T0300Z/

   OH 
   .    OHIO COUNTIES INCLUDED ARE

   ALLEN                DEFIANCE            FULTON              
   HENRY                PAULDING            PUTNAM              
   VAN WERT             WILLIAMS