Severe Thunderstorm Warning 114, NWS Wilmington, OH

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON OH
427 PM EDT FRI JUL 19 2013

.SYNOPSIS...
HIGH PRESSURE WILL MOVE SOUTHEAST OF THE REGION TONIGHT...AS A
COLD FRONT APPROACHES FROM THE NORTHWEST. THE COLD FRONT WILL
CROSS THE REGION SATURDAY...PROVIDING LIKELY SHOWERS AND
THUNDERSTORMS. A SLIGHTLY COOLER AIR MASS WILL BE IN PLACE ON
SUNDAY...BEFORE ADDITIONAL MOISTURE MOVES INTO THE OHIO VALLEY ON
MONDAY.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
AN VERY UNSTABLE ATMOSPHERE HAS TAKEN SHAPE OVER THE ILN CWA
TODAY...WITH NUMEROUS THUNDERSTORM CELLS PRETTY MUCH ALL OVER THE
PLACE. A MODIFIED 12Z KILN SOUNDING WITH PRE-CONVECTIVE T/TD
INDICATED ABOUT 3500 J/KG OF UNCAPPED SBCAPE. AS MOST OF THE
ACTIVITY SEEMS TO BE DIURNALLY DRIVEN (NOT MUCH IN THE WAY OF
LARGE-SCALE FORCING) THE EXPECTATION WOULD BE FOR IT TO DISSIPATE
OVER THE NEXT FEW HOURS. A FEW SEVERE STORMS ARE POSSIBLE WITH THE
INSTABILITY IN PLACE...BUT THESE WILL NOT BE SUSTAINED (WEAK SHEAR
BELOW 20 KNOTS FROM 0-6KM). THE STORMS ARE PRODUCING LARGE AMOUNTS OF
LIGHTNING AND HEAVY DOWNPOURS ARE ALSO EXPECTED.

THE HEAT ADVISORY AND EXCESSIVE HEAT WARNING WILL BE CONTINUED FOR
ANOTHER FEW HOURS...BUT WILL BE DROPPED LATER THIS AFTERNOON OR
THIS EVENING. MIN TEMPS WILL STILL BE QUITE WARM TONIGHT (IN THE
LOWER TO MID 70S).

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
THE MODEL CONSENSUS SUPPORTS A DECREASE IN POPS THROUGH MOST OF
THE OVERNIGHT HOURS...AS INSTABILITY WANES DUE TO THE LOSS OF
DAYTIME HEATING. HOWEVER...A COLD FRONT WILL BE MOVING THROUGH
MICHIGAN TONIGHT AND INTO THE MORNING...AND CONVECTION AHEAD OF THE
FRONT MAY SNEAK INTO THE NORTHERN CWA OVERNIGHT. SEVERE CHANCES
WOULD BE MINIMAL AS THE TIMING IS NOT FAVORABLE FROM A PERSPECTIVE
OF INSTABILITY...AND OVERALL STORM COVERAGE IS EXPECTED TO BE
RATHER MARGINAL.

THE POTENTIAL FOR ADDITIONAL DEVELOPMENT TOMORROW...INCLUDING THE
POSSIBILITY FOR SEVERE WEATHER...IS THE PRIMARY FORECAST CONCERN.
FRONTAL CONVERGENCE APPEARS SUPPORTIVE OF CONVECTIVE DEVELOPMENT
(PERHAPS EVEN SLIGHTLY MORE SO THAN IN LOWER MICHIGAN RIGHT
NOW...WHICH APPEARS TO BE WELL AHEAD OF THE WIND SHIFT).
INSTABILITY FORECASTS ARE CERTAINLY NOT AS STRONG AS TODAY...BUT
MLCAPE OF AROUND 1500-2000 J/KG SEEMS A REASONABLE ASSESSMENT. THE
SHEAR PROFILE DOES NOT NECESSARILY SUGGEST THE STRONGEST OF STORM
SCENARIOS (MOSTLY UNIDIRECTIONAL AND MORE PARALLEL THAN
PERPENDICULAR TO THE FRONT)...BUT IT IS STRONG ENOUGH TO ALLOW FOR
STORM ORGANIZATION WITH SOME BOWING SEGMENTS AND SUSTAINED
CLUSTERS (25-35 KNOTS 0-6KM BUT RATHER WEAK IN THE LOWEST LEVELS).
THE STRONGEST SHEAR AND STRONGEST INSTABILITY WILL BE UNLIKELY TO
BE JUXTAPOSED...BUT THEY WILL OVERLAP ENOUGH TO SUPPORT WHAT
APPEARS TO BE A STANDARD SLIGHT-RISK TYPE SEVERE THREAT IN THE ILN
CWA.

TIMING AND PLACEMENT CONCERNS WILL END UP NECESSITATING A CAREFUL
LOOK AT HOW UPSTREAM ACTIVITY AFFECTS THE AREA. THE AREA OF
ENHANCED DEEP MOISTURE (AS SEEN ON 1000-500MB RH) ASSOCIATED WITH
THE PRE-FRONTAL FORCING WILL ALREADY BE INTO THE FAR NORTHERN CWA
BY 12Z...NOT EXACTLY A FAVORABLE TIMING. ALTHOUGH SOME DEVELOPMENT
COULD OCCUR AT JUST ABOUT ANY TIME (AND ONGOING PRECIPITATION
SEEMS POSSIBLE EVEN DURING THE DIURNAL MIN)...MOST OF THE HIGH-RES
GUIDANCE HINTS AT EARLIER-THAN-STANDARD-DIURNAL REDEVELOPMENT (AND
THUS BEST CHANCES FOR SEVERE) OCCURRING MID-DAY ACROSS THE HEART
OF THE CWA...FOCUSING THE DOWNSTREAM PROPAGATION AND SEVERE
POTENTIAL IN THE SOUTHERN TWO-THIRDS OF THE CWA (OR FOR
INSTANCE...SOUTH OF A BROOKVILLE INDIANA TO LANCASTER OHIO LINE).
THE UPSTREAM UNCERTAINTY WILL PRECLUDE BREAKING OUT THE HWO INTO
GROUPS...SO A ONE-SEGMENT ISSUANCE WILL BE USED TO HIGHLIGHT THE
POTENTIAL WIND THREAT.

TEMPERATURES TOMORROW WILL CERTAINLY BE IMPACTED BY CLOUDS AND
STORMS...AND THUS THE HIGHEST TEMPS WILL BE FURTHER AWAY FROM THE
FRONT...IN THE SOUTHEASTERN CWA. STILL LOOKS LIKE 90 WILL BE
POSSIBLE IN THE SE...BUT HELD TEMPS IN THE LOWER 80S IN THE FAR NORTH.

THE FRONT SLOWS DOWN ONCE IT GETS NEAR THE OHIO RIVER...AND
ALTHOUGH THE SURFACE FRONT DOES APPEAR TO GET TO THE SOUTHERN CWA
BORDER...IT IS NOT FAR ENOUGH TO TOTALLY REMOVE POPS OVERNIGHT.
HOWEVER...THE NORTHERN HALF OF THE CWA LOOKS RATHER DRY...AS THE
POST-FRONTAL AIRMASS IS MUCH DRIER (TD VALUES DROPPING TO AROUND
60 DEGREES IN THE FAR NORTH).

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
A COLD FRONT WILL STALL OUT TO THE SOUTH OF THE OHIO RIVER ON SUNDAY
AND WILL BEGIN TO LIFT BACK NORTH ON SUNDAY NIGHT. THE MAIN FOCUS FOR
PRECIPITATION WILL BE ACROSS THE SOUTH ON SUNDAY AND SUNDAY NIGHT IN
THE VICINITY OF THE FRONT. AN UPPER LEVEL DISTURBANCE WILL CROSS THE
REGION ON MONDAY AND WILL INTERACT WITH THE FRONTAL BOUNDARY. THIS
WILL RESULT IN ORGANIZED CONVECTION DURING THE DAY MONDAY WITH
PRECIPITATION LIKELY FOR ALL ZONES.

THE DISTURBANCE WILL SLIDE TO OUR EAST MONDAY NIGHT WHICH SHOULD
BRING LOWERING CHANCES FOR PRECIPITATION OVERNIGHT MONDAY NIGHT.
ANOTHER DISTURBANCE WILL BE POISED TO CROSS THE AREA TUESDAY...WITH
A ROUND OF MAINLY AFTERNOON THUNDERSTORMS EXPECTED. THIS SECOND
DISTURBANCE EXITS THE REGION RATHER SLOWLY...THEREFORE AM
FORECASTING CHANCE FOR THUNDERSTORMS INTO THE WEDNESDAY AFTERNOON
TIME PERIOD ACROSS THE EAST AS THE DISTURBANCE MOVES AWAY.

UPPER TROUGH OVER THE GREAT LAKES AMPLIFIES ON WEDNESDAY NIGHT AND
SHIFTS ITS AXIS AND BETTER FORCING TO OUR EAST. THIS SHOULD LOWER
CHANCES FOR PRECIPITATION STARTING WEDNESDAY EVENING...LASTING
THROUGH FRIDAY.

WITH THE UPPER TROUGH EXTENDING ACROSS THE EASTERN PORTIONS OF THE
CONUS DURING THE EXTENDED TIME PERIOD...TEMPERATURES WILL RUN NEAR
NORMAL TO SLIGHTLY BELOW NORMAL FOR MUCH OF THE WORK WEEK.

&&

.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
SCATTERED THUNDERSTORMS HAVE DEVELOPED IN THE WARM AND HUMID
AIRMASS OVER THE REGION TODAY. BEST COVERAGE OF THE STORMS WILL
OCCUR ALONG AND SE OF INTERSTATE 71. THESE STORMS ARE DIURNALLY
DRIVEN BY AFTN HEATING AND WILL END EARLY THIS EVENING. HAVE KEPT
CIGS IN VFR CATEGORY WITH A TEMPO AT ALL TAF SITES BUT KDAY. CAN
NOT RULE OUT AN ISOLD SHOWER LATE TONIGHT BUT DUE TO LIMITED
COVERAGE...HAVE KEPT THE OVERNIGHT DRY. EXPECT BETTER COVERAGE OF
STORMS SATURDAY AHEAD OF AN APPROACHING COLD FRONT ON SATURDAY.
HAVE PREVAILING SHOWERS AT ALL TAF SITES WITH A MENTION OF
THUNDER.

OUTLOOK...THUNDERSTORMS LIKELY MONDAY.

&&

.ILN WATCHES/WARNINGS/ADVISORIES...
OH...HEAT ADVISORY UNTIL 9 PM EDT THIS EVENING FOR OHZ026-034-035-
     042>046-051>056-060-062>065-070>074-078>082-088.
     EXCESSIVE HEAT WARNING UNTIL 9 PM EDT THIS EVENING FOR OHZ061-
     077.
KY...HEAT ADVISORY UNTIL 9 PM EDT THIS EVENING FOR KYZ089>100.
IN...HEAT ADVISORY UNTIL 9 PM EDT THIS EVENING FOR INZ050-058-059-
     066-073>075-080.

&&

SYNOPSIS...HATZOS
NEAR TERM...HATZOS
SHORT TERM...HATZOS
LONG TERM...LATTO
AVIATION...AR

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PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE WILMINGTON OH
417 PM EDT FRI JUL 19 2013

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0344 PM     TSTM WND DMG     5 S HANOVER             40.01N 82.26W
07/19/2013                   LICKING            OH   LAW ENFORCEMENT

            NUMEROUS TREES DOWN ACROSS SOUTHEASTERN LICKING
            COUNTY...INCLUDING THE HANOVER AREA.

&&

KURZ

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE WILMINGTON OH
445 PM EDT FRI JUL 19 2013

OHZ070-071-192130-
BUTLER OH-WARREN OH-
445 PM EDT FRI JUL 19 2013

...A STRONG THUNDERSTORM WILL AFFECT WESTERN WARREN AND SOUTHEASTERN
BUTLER COUNTIES THROUGH 530 PM EDT...

AT 440 PM EDT...RADAR INDICATED A STRONG THUNDERSTORM NEAR
HAMILTON...MOVING EAST AT 15 MPH.

STORM HAZARDS INCLUDE...
WINDS TO 45 MPH...
PEA SIZE HAIL...
FREQUENT CLOUD TO GROUND LIGHTNING...

SOME LOCATIONS THAT MAY BE AFFECTED INCLUDE...WEST CHESTER...
MONROE...MIDDLETOWN...MASON AND KINGS ISLAND.

ALSO...MAUSTOWN...BECKETT RIDGE...TRENTON...HUGHES...MAUD...SOUTH
MIDDLETOWN...KINGS MILLS AND HAGEMAN ARE NEAR THE PATH OF THIS STRONG
THUNDERSTORM.

DO NOT STAY IN THE OPEN NOR SEEK SHELTER UNDER TREES WHEN LIGHTNING
THREATENS. MOVE INDOORS WHEN A THUNDERSTORM APPROACHES.

LAT...LON 3953 8427 3934 8425 3931 8463 3946 8460

ASL

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE WILMINGTON OH
456 PM EDT FRI JUL 19 2013

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0304 PM     TSTM WND DMG     SUMMERSIDE              39.12N 84.29W
07/19/2013                   CLERMONT           OH   TRAINED SPOTTER

            A COUPLE 6 TO 8 INCH DIAMETER BRANCHES DOWN.

&&

KURZ

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