Probabilities of damaging thunderstorm winds or wind gusts of 50 knots (58 mph) or higher within 25 miles of a point. Purple area: 45 percent. Red area: 30 percent. Yellow area: 15 percent. Brown area: five percent. Grey area outlined in black: 10 percent or greater probability of “significant” wind gusts of 75 mph or greater within 25 miles of a point. Highlighted counties: County warning area of the northern Indiana NWS office.

See an update to this post.

There is a slight risk of severe thunderstorms in northeastern, northwestern and north central Indiana between 9 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 8:52 a.m. EDT.

The greatest threats are damaging straight-line thunderstorm winds of 58 mph or greater and hail of one inch or greater diamter. A small part of northwestern Indiana has an enhanced risk of “significant” damaging thunderstorms winds (gusts of 75 mph or greater).

The slight risk area includes the following counties in IMO SKYWARN quadrant two: Allen (Ind.), Whitley, Huntington, Wells, Adams, Blackford and parts of Jay and Paulding.

The counties (or parts of counties) listed above have the following probabilities of the following types of severe weather within 25 miles of a point:

Some thunderstorms might occur this afternoon but the chance is greatest tonight, according to the “Hazardous Weather Outlook” that the NWS northern Indiana office issued at 4:28 a.m. EDT. That outlook indicates that SKYWARN storm spotter activation will likely be needed tonight.

As always when this amount of risk is present, people planning outdoor activities this afternoon and tonight should assure that they have a way of learning of any watches or warnings that the NWS might issue and a way to quickly take shelter. SKYWARN storm spotters should fuel up their vehicles, make sure their communications equipment is ready and review reporting criteria and procedures.

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

Probability of damaging thunderstorm winds or wind gusts of 50 knots (58 mph) or higher within 25 miles of a point. Learn why 15 percent is meaningful.

After issuing “Day 1 Convective Outlooks” at 2 a.m. and 9 a.m. EDT that indicated no risk of severe weather today in Indiana, the National Weather Service (NWS) Storm Prediction Center (SPC) issued a revised outlook at 12:30 p.m. that indicated a slight risk of severe weather in most of the northern half of Indiana. That risk continues in the updated outlook that the SPC issued at 3:45 p.m. EDT.

The primary threat is damaging straight-line thunderstorm winds of 58 mph or stronger. The outlook indicates a 15 percent probability of such winds within 25 miles of a point. The probably of of a tornado in the area is less than two percent and the probability of large hail is less than five percent.

The slight risk area includes all of the 37-county warning area of the northern Indiana NWS office, except for a bit of the northwest corner. The slight risk area includes all county in IMO SKYWARN quadrant two.

The latest “Hazardous Weather Outlook” from the northern Indiana NWS office, issued at 12:36 p.m. EDT, indicated that SKYWARN spotter activation was not anticipated at that time.

There is a chance for thunderstorms today and tonight in northeastern Indiana, southern Lower Michigan and northwestern Ohio, but forecasters do not expect the storms to be severe, according to the “Hazardous Weather Outlook” that the northern Indiana National Weather Service (NWS) office issued at 5:25 a.m.

Wind gusts to 45 mph are possible, however, with the strongest storms, so it would be a good idea to put away any lightweight lawn furniture or anything else that could blow away. Some storms could also bring locally heavy rainfall.

There is a chance for more storms tomorrow (Tuesday, June 25), a few of which could produce isolated wind gusts approaching severe limits (58 mph). If that happens, it will most likely be east of Interstate 69.

NWS meteorologists did not anticipate any activation of SKYWARN storm spotters at the time they wrote the outlook.

Heavy rainfall from thunderstorms could cause localized flooding in northeastern Indiana, southern Lower Michigan and northwestern Ohio today, according to the “Hazardous Weather Outlook” that the northern Indiana office of the National Weather Service (NWS) issued at 5:43 a.m. Some strong storms this afternoon and early evening could produce wind gusts to 45 mph. While some storms might be strong, forecasters do not expect any of them to reach severe thunderstorm criteria (winds of at least 58 mph and/or hail of at least one inch in diameter).

There’s a chance of thunderstorms in northeastern Indiana through Friday and again Sunday afternoon through Tuesday, but forecasters do not expect severe storms, according to the “Hazardous Weather Outlook” the northern Indiana National Weather Service (NWS) office issued at 5:23 a.m. EDT.

Nonetheless, an isolated strong wind gust or small hail might be possible today or tonight. And Friday’s storms could produce very heavy rainfall and localized flooding.

URGENT - IMMEDIATE BROADCAST REQUESTED
   SEVERE THUNDERSTORM WATCH NUMBER 321
   NWS STORM PREDICTION CENTER NORMAN OK
   155 PM EDT WED JUN 18 2014

   THE NWS STORM PREDICTION CENTER HAS ISSUED A

   * SEVERE THUNDERSTORM WATCH FOR PORTIONS OF 
     NORTHERN INDIANA
     CENTRAL AND SOUTHERN LOWER MICHIGAN
     NORTHWEST OHIO
     LAKE ERIE

   * EFFECTIVE THIS WEDNESDAY AFTERNOON AND EVENING FROM 155 PM
     UNTIL 900 PM EDT.

   * PRIMARY THREATS INCLUDE...
     SCATTERED DAMAGING WIND GUSTS TO 70 MPH POSSIBLE
     ISOLATED LARGE HAIL EVENTS TO 1.5 INCHES IN DIAMETER POSSIBLE

   THE SEVERE THUNDERSTORM WATCH AREA IS APPROXIMATELY ALONG AND 60
   STATUTE MILES EAST AND WEST OF A LINE FROM 15 MILES NORTHEAST OF
   FLINT MICHIGAN TO 70 MILES WEST SOUTHWEST OF TOLEDO OHIO.  FOR A
   COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE
   UPDATE (WOUS64 KWNS WOU1).

   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.

   &&

   DISCUSSION...A QLCS WITH EMBEDDED BOWING STRUCTURES SHOULD CONTINUE
   TO INTENSIFY AS IT MOVES EAST AND SOUTHEAST ACROSS THE WATCH AREA
   THIS AFTERNOON. DAMAGING WINDS WILL BE THE PRIMARY HAZARD...THOUGH
   ISOLATED OCCURRENCES OF LARGE HAIL ARE ALSO POSSIBLE.

   AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
   TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60
   KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500. MEAN STORM
   MOTION VECTOR 27035.

BULLETIN - IMMEDIATE BROADCAST REQUESTED
   SEVERE THUNDERSTORM WATCH OUTLINE UPDATE FOR WS 321
   NWS STORM PREDICTION CENTER NORMAN OK
   155 PM EDT WED JUN 18 2014

   SEVERE THUNDERSTORM WATCH 321 IS IN EFFECT UNTIL 900 PM EDT
   FOR THE FOLLOWING LOCATIONS

   INC001-003-033-039-049-069-085-087-099-103-113-131-141-151-169-
   179-183-190100-
   /O.NEW.KWNS.SV.A.0321.140618T1755Z-140619T0100Z/

   IN 
   .    INDIANA COUNTIES INCLUDED ARE

   ADAMS                ALLEN               DE KALB             
   ELKHART              FULTON              HUNTINGTON          
   KOSCIUSKO            LAGRANGE            MARSHALL            
   MIAMI                NOBLE               PULASKI             
   ST. JOSEPH           STEUBEN             WABASH              
   WELLS                WHITLEY             


   MIC015-023-025-027-037-045-049-059-065-075-077-087-091-093-099-
   115-125-147-149-155-161-163-190100-
   /O.NEW.KWNS.SV.A.0321.140618T1755Z-140619T0100Z/

   MI 
   .    MICHIGAN COUNTIES INCLUDED ARE

   BARRY                BRANCH              CALHOUN             
   CASS                 CLINTON             EATON               
   GENESEE              HILLSDALE           INGHAM              
   JACKSON              KALAMAZOO           LAPEER              
   LENAWEE              LIVINGSTON          MACOMB              
   MONROE               OAKLAND             SHIAWASSEE          
   ST. CLAIR            ST. JOSEPH          WASHTENAW           
   WAYNE                


   OHC003-039-051-063-069-095-125-137-161-171-173-190100-
   /O.NEW.KWNS.SV.A.0321.140618T1755Z-140619T0100Z/

   OH 
   .    OHIO COUNTIES INCLUDED ARE

   ALLEN                DEFIANCE            FULTON              
   HANCOCK              HENRY               LUCAS               
   PAULDING             PUTNAM              VAN WERT            
   WILLIAMS             WOOD       

 The National Weather Service Storm Prediction Center has issued Mesoscale Discussion #1061, which indicates a 40 percent chance of a watch being issued that could include northern Indiana.