Hail and Heavy Rain in Nebraska, June 24 to 25, 2011

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
644 AM CDT FRI JUN 24 2011

.UPDATE...LOW LEVEL WAA ON THE BACK SIDE OF THE SURFACE RIDGE
CURRENTLY OVER THE MISSOURI VALLEY IS INDUCING ENOUGH ISENTROPIC
UPGLIDE AND SATURATION ALONG THE 305-310K SURFACES FOR
PRECIPITATION PRODUCTION ACROSS THE AREA THIS MORNING.
INSTABILITY IS VERY LIMITED SO FAR THIS MORNING...HOWEVER
PROXIMITY SOUNDINGS PER LAPS...RUC AND NAM BUFR DATA SUGGEST AIR
PARCELS ROOTED TO BETWEEN 750MB AND 700MB MAY ENCOUNTER JUST
ENOUGH INSTABILITY FOR UPDRAFT PRODUCTION...THUS RESULTING IN
ISOLATED SHOWER AND THUNDERSTORM ACTIVITY THROUGH THE MORNING
HOURS. WITHIN THE LAST HOUR...KUEX INDICATES EXPANDING CONVECTIVE
ACTIVITY OVER VALLEY AND SHERMAN COUNTIES...WITH THIS ACTIVITY
MOVING EAST/SOUTHEAST. WENT AHEAD AND SENT AN UPDATE TO THE
FORECAST TO INCREASE POPS SOMEWHAT ACROSS OUR NORTH THROUGH THE
MORNING HOURS. ALSO OF INTEREST IS A CLUSTER OF CONVECTION
CURRENTLY OVER WESTERN NEBRASKA. THIS AREA OF CONVECTION HAS HELD
TOGETHER VERY WELL THROUGH THE PAST COUPLE OF HOURS AND APPEARS TO
BE ASSOCIATED WITH A SUBTLE MID LEVEL SHORT WAVE ALSO PUSHING OVER
THE REGION THIS MORNING. IT REMAINS UNCERTAIN HOW LONG THIS
CONVECTIVE CLUSTER WILL HOLD TOGETHER SINCE NONE OF THE MODEL
GUIDANCE IS HANDLING IT VERY WELL. ALL THAT BEING SAID...WENT
AHEAD AND ALSO EXPANDED POPS ACROSS THE ENTIRE CWA THROUGH THE
MORNING HOURS TO ACCOUNT FOR CURRENT ACTIVITY OVER THE AREA...AS
WELL AS THE THE POSSIBILITY OF THE WESTERN CONVECTIVE CLUSTER
INFILTRATING OUR CWA LATER THIS MORNING.

&&

.PREV DISCUSSION... /ISSUED 618 AM CDT FRI JUN 24 2011/

AVIATION...VFR CONDITIONS TO CONTINUE AT THE TERMINAL THROUGH
06Z...AT WHICH TIME MVFR CONDITIONS WILL BE POSSIBLE AT KGRI.
RADAR INDICATES ISOLATED CONVECTIVE ACTIVITY DEVELOPING ALONG A
LINE BETWEEN KODX TO KLXN. GIVEN THE ISOLATED NATURE OF OF THIS
ACTIVITY...CHANCES OF KGRI OBSERVING PRECIPITATION REMAIN VERY LOW
AND WILL LEAVE OUT OF THE TAF FOR THE TIME BEING. THAT BEING
SAID...SHOULD THIS CONVECTION HOLD TOGETHER AND/OR INCREASE IN
SPATIAL COVERAGE...IT IS POSSIBLE -TSRA WILL NEED TO BE ADDED TO
THE TAF FOR A TIME A LITTLE LATER THIS MORNING. THE LOW LEVEL WIND
FIELD WILL BECOME MORE ESTABLISHED FROM THE SOUTHEAST LATER THIS
MORNING...LIKELY INCREASING TO NEAR 12KTS LATER TODAY. BETTER
CHANCES FOR SHOWERS AND THUNDERSTORMS WILL PRESENT THEMSELVES AT
KGRI STARTING 06Z TONIGHT...AND FOR NOW WILL GO WITH A PROB30
GROUP 06Z-12Z. GUIDANCE IS ALSO SUGGESTING CEILINGS NEAR 2KFT AGL
AND VISIBILITY RESTRICTIONS POSSIBLE AFTER 06Z.

PREV DISCUSSION... /ISSUED 416 AM CDT FRI JUN 24 2011/

DISCUSSION...MAIN FOCUS IS ON TSTM CHCS...FOLLOWED BY INCREASING
TEMPERATURES OVER THE WEEKEND...AND AGAIN NEXT WEEK. CONVECTION
DEVELOPED ALONG THE HIGH PLAINS OVERNIGHT WHICH HAS BEGUN TO WORK
ITS WAY EASTWARD INTO OUR CWA EARLY THIS MORNING AND WILL CARRY SOME
ISOLATE POPS FOR THE MORNING TIME FRAME.

AS THE SURFACE RIDGE AXIS CONTINUES TO SHIFT EASTWARD TODAY MOISTURE
WILL WORK ITS WAY NORTHWARD INTO OUR REGION ABOARD SOUTHEASTERLY
WINDS.  SFC DPS ARE EXPECTED TO CLIMB INTO THE 60S DURING THE DAY
WHILE THE WARM FRONTAL BOUNDARY SETS UP ACROSS SOUTHERN
KANSAS...WITH SURFACE LOW PRESSURE SYSTEMS LOCATED IN EASTEN WY
AND THE OKLAHOMA PANHANDLE. CONVECTION IS EXPECTED TO REDEVELOP
ALONG THE TROUGH ALONG THE HIGH PLAINS REGION THIS EVENING AS A
MID LEVEL SHORTWAVE TROUGH EMERGES FM THE ROCKIES AND CROSSES THE
CENTRAL PLAINS...HOWEVER CANNOT COMPLETELY RULE OUT A STORM OR TWO
NORTH OF THE FRONTAL BOUNDARY OVERNIGHT AS THE LLVL JET INCREASES
TO 40KTS. THE HIGH PLAINS CONVECTION IS EXPECTED TO ORGANIZE AND
ROLL EASTWARD ACROSS OUR REGION MAINLY AFTER MIDNIGHT. SREF
MUCAPES ARE ON THE ORDER OF 1500 J/KG TO 2000 J/KG WITH SHEAR
VALUES OF 40 TO 50KTS. ELEVATED SEVERE CONVECTION REMAINS POSSIBLE
TONIGHT WITH POTENTIAL FOR LARGE HAIL...DAMAGING WINDS AND HEAVY
RAINFALL WITH PRECIPITABLE WATER VALUES IN EXCESS OF AN INCH.

THERE MAY BE SOME LINGERING CONVECTION DURING THE MORNING ON
SATURDAY WITH REDEVELOPMENT POSSIBLE AGAIN IN THE EVENING/NIGHT.
THE WARM FRONTAL BOUNDARY NOSES NORTHEAST INTO NORTHEAST KANSAS BY
SATURDAY EVENING.  WARM AIR WILL REACH NORTH CENTRAL KANSAS WITH
TEMPS EXPECTED TO REACH NEAR 90F SATURDAY AFTNN. MORE NOTICEABLE
WILL BE THE INCREASE IN MOISTURE DURING THE DAY WITH DPS RISING TO
THE UPPER 60S AS THEY POOL AROUND THE BOUNDARY. THIS WILL RESULT
IN EXTREMELY UNSTABLE CONDITIONS DURING THE DAY WITH SFC BASED
CAPES PROGGED NEAR 4000 J/KG. IN THEORY THE CAP SHOULD HOLD DURING
THE DAY WITH WARM MID LEVEL TEMPS PROGGED ALONG THE BOUNDARY. IF
STORMS DO DEVELOP HOWEVER...THE WOULD RAPIDLY BECOME SEVERE. HAVE
MAINLY FOCUSED CONVECTIVE CHCS ALONG OUR EASTERN CWA SATURDAY
NIGHT ALONG THE ORIENTATION OF THE LLVL JET HOWEVER WILL NEED TO
MONITOR HIGH PLAINS CONVECTIVE TRENDS TO SEE IF WESTERN STORMS MAY
HOLD TOGETHER AND REACH OUR WESTERN CWA OVERNIGHT.

HEADING INTO SUNDAY...FLOW ALOFT TRANSITIONS MORE TO THE SOUTHWEST
AHEAD OF AN UPPER TROUGH CROSSING THE NORTHERN PLAINS REGION.
SURFACE WARM FRONTAL BOUNDARY EDGES NORTHWARD AND MUCH WARMER AIR
PUSHES EAST FM THE HIGH PLAINS WITH H85 TEMPS NEARING 30C BY 00Z
MONDAY IN OUR SW CWA. THE HEAT REALLY TURNS ON IN OUR SW CWA WITH
AFTN TEMPS EXPECTED TO CLIMB WELL INTO THE 90S...WITH UPPER 80S TO
90S EXPECTED ELSEWHERE. IT WILL AGAIN BE ANOTHER MUGGY/HUMID DAY
AS THE HOT TEMPS COMBINE WITH DPS AROUND 70F AGAIN. THE CAP IS
EXPECTED TO HOLD DURING THE DAY AS MID LEVEL TEMPS AVERAGE 14-17C
NE/SW ACROSS THE CWA...HOWEVER DID MAINTAIN JUST A SLIGHT CHC
ACROSS THE EASTERN TWO THIRDS OF THE CWA IN CASE SOMETHING GOES
EAST OF THE DRY LINE. OTHERWISE CONVECTION IS EXPECTED TO DEVELOP
WELL TO OUR NORTH ACROSS THE DAKOTAS DURING THE DAY ALONG AN
ADVANCING SFC COLD FRONTAL BOUNDARY. THE FRONT CROSSES OUR CWA
SUNDAY NIGHT BRINGING ANOTHER ROUND OF CONVECTIVE POTENTIAL.
SEVERE STORMS ARE POSSIBLE DURING THIS TIME FRAME IN THE PRESENCE
OF HIGH DEEP LAYER SHEAR AND INSTABILITY. HEAVY RAINFALL IS ALSO A
CONCERN WITH PRECIPITABLE WATER VALUES IN EXCESS OF AN INCH AND A
HALF.

THE FRONT FINALLY SCOURS THE LLVL MOISTURE BY MONDAY WITH PCPN CHCS
DIMINISHING MONDAY MORNING.  THE FRONT LOOKS LIKE IT MAY SETTLE FAR
ENOUGH SOUTH OF OUR CWA MONDAY NIGHT TO PRECLUDE PCPN CHCS AT LEAST
ON THE NEBRASKA SIDE BUT WILL LET LATER SHIFTS REEVALUATE FRONTAL
POSITION TO AVERT FLIP FLOPPING POPS.  FRONT LIFTS NORTHWARD TUESDAY
WITH ANOTHER ROUND OF CONVECTION POSSIBLE...THEN THE HEAT REALLY
TURNS ON MID WEEK ON AS THE UPPER RIDGE AXIS BUILDS NORTH ONTO THE
CENTRAL PLAINS.  H85 TEMPS ARE PROGGED TO REACH THE LOW 30S IN OUR
WEST ON WEDNESDAY AND BE IN THE LOW 30S ACROSS THE ENTIRE CWA
THURSDAY.  VERY HOT CONDITIONS ARE EXPECTED AND HAVE BUMPED UP
TEMPERATURES ABOVE THE CENTURY MARK IN NORTH CENTRAL KANSAS AND
WOULD NOT BE SURPRISED TO SEE IF THIS IS EXPANDED NORTHEASTWARD WITH
TIME.  HIGH DPS IN THE EAST WILL AGAIN RESULT IN MUGGY CONDITIONS.
SO FAR HEAT INDEX VALUES ARE NOT TOO FAR OFF FROM AMBIENT TEMPS BUT
WILL NEED TO MONITOR TRENDS OF THIS.

FINAL THOUGHT FOR OVERNIGHT PERIODS THE NEXT COUPLE OF NIGHTS IS
POTENTIAL FOR SOME FOG/REDUCED VSBYS AS MOISTURE POOLS ALONG THE
FRONTAL BOUNDARY...AND LLVL FLOW IS FROM A LIGHT EASTERLY
DIRECTION. WILL CONTINUE TO MONITOR TRENDS OF THIS.

&&

.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&

UPDATE/AVIATION...BRYANT

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE HASTINGS NE
635 AM CDT FRI JUN 24 2011

KSZ005>007-017>019-NEZ039>041-046>049-060>064-072>077-082>087-
251200-
PHILLIPS-SMITH-JEWELL-ROOKS-OSBORNE-MITCHELL-VALLEY-GREELEY-NANCE-
SHERMAN-HOWARD-MERRICK-POLK-DAWSON-BUFFALO-HALL-HAMILTON-YORK-
GOSPER-PHELPS-KEARNEY-ADAMS-CLAY-FILLMORE-FURNAS-HARLAN-FRANKLIN-
WEBSTER-NUCKOLLS-THAYER-
635 AM CDT FRI JUN 24 2011

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTH CENTRAL NEBRASKA AND
PORTIONS OF NORTH CENTRAL KANSAS.

.DAY ONE...TODAY AND TONIGHT.

SHOWERS AND ISOLATED THUNDERSTORMS WILL BE POSSIBLE ACROSS THE
OUTLOOK AREA THIS MORNING. SEVERE WEATHER IS NOT EXPECTED WITH THIS
ACTIVITY.

THUNDERSTORM CHANCES INCREASE AGAIN TONIGHT...MAINLY AFTER DARK.
SEVERE THUNDERSTORMS ARE POSSIBLE WHICH MAY PRODUCE LARGE HAIL THE
SIZE OF QUARTERS...DAMAGING WINDS OF 60 MPH AND LOCALLY HEAVY
RAINFALL IN EXCESS OF AN INCH.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY.

CHANCES FOR THUNDERSTORMS EXIST FROM SATURDAY THROUGH TUESDAY.

STRONG TO SEVERE THUNDERSTORMS ARE POSSIBLE ACROSS THE OUTLOOK
AREA OVER THE WEEKEND. THE SEVERE STORMS WILL BE CAPABLE OF
PRODUCING GOLF BALL SIZE HAIL...DAMAGING WINDS OF 60 MPH AND
HEAVY RAINFALL IN EXCESS OF 1 AND 2 INCHES.

HEAT INDICES ARE FORECAST NEAR OR ABOVE 100 DEGREES ACROSS NORTH
CENTRAL KANSAS ON SUNDAY...AND AGAIN ON WEDNESDAY AND THURSDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED AFTER DARK TONIGHT.

&&

MORE INFORMATION MAY BE OBTAINED AT THE FOLLOWING WEB PAGE:
   HTTP://WWW.WEATHER.GOV/HASTINGS  (ALL LOWERCASE)

BRYANT