Damaging Winds in Nebraska, August 30, 2010

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HASTINGS NE
321 PM CDT MON AUG 30 2010

.SHORT TERM...TONIGHT THROUGH 12Z WEDNESDAY. PRIMARY FORECAST
CONCERN LIES WITH PRECIPITATION CHANCES THROUGH THE ENTIRE PERIOD.

12Z UPPER AIR OBSERVATIONS AND CURRENT SATELLITE DATA SHOWING THE
CONUS REMAINING UNDER AN AMPLIFIED PATTERN WITH A TROUGH OVER THE
WESTERN ROCKIES/WEST COAST AND HIGH PRESSURE DOMINATING THE GULF
COAST REGION AND EAST COAST...RESULTING IN SOUTHWESTERLY FLOW ACROSS
THE CENTRAL PLAINS.  AN UPPER LEVEL DISTURBANCE CAN BE SEEN IN SAT
IMAGERY SHIFTING OUT OF THE ROCKIES AND ONTO THE HIGH PLAINS
ACCOMPANYING A LARGER DISTURBANCE ACROSS WY/MT.  HASNT BEEN A LOT OF
CHANGE WITH THE SFC PATTERN...WITH LOW PRESSURE/FRONTAL BOUNDARY
EXTENDING FROM NERN CO INTO CENTRAL SD...WITH A TROUGH DRAPED SOUTH
NEAR THE CO/KS BORDER. THE COMBINATION OF A TIGHTENED PRESSURE
GRADIENT ALONG WITH STRONGER WINDS MIXING DOWN TO THE SFC HAS
BROUGHT ANOTHER ROUND OF GUSTY SOUTHERLY WINDS TO THE CWA...WHICH
HAVE GENERALLY BEEN 20 TO 25 MPH SUSTAINED WITH GUSTS NEAR 30 TO 35
MPH.

SHOWERS AND A FEW ISOLATED THUNDERSTORMS HAVE ALREADY POPPED UP TO
THE WEST OF THE CWA...A TREND THAT IS EXPECTED TO CONTINUE AS WE
COME UNDER MORE INFLUENCE OF THE LIFT FROM THE APPROACHING UPPER
LEVEL DISTURBANCE. LAPS DATA SHOWING INSTABILITY GENERALLY RANGING
FROM 1000-2000J/KG OF CAPE ACROSS THE CWA AND DEEP LAYER SHEAR
INCREASING TO NEAR 35KTS IN THE FAR WESTERN PORTIONS...SO THREAT OF
SOME STRONG/SEVERE THUNDERSTORMS WILL LINGER...WITH DAMAGING
WINDS/HAIL REMAINING THE PRIMARY THREAT.  THIS DISTURBANCE IS
EXPECTED TO REMAIN ON A MORE NORTHEASTERLY TRACK THROUGH THE REST OF
THE AFTERNOON AND EVENING...AND IS EXPECTED TO HELP KEEP THE BULK OF
THE ACTIVITY THAT FIRES TO THE WEST AND EVENTUALLY NORTH OF THE CWA
INTO THE DAKOTAS...WHERE THE BETTER COMBO OF INSTABILITY AND FORCING
WILL BE.  COULD BE ACTIVE FOR A FEW HOURS ESP IN OUR NW CORNER...BUT
EXPECT THAT THUNDERSTORMS FOR THE REMAINDER OF THE CWA WOULD BE
FAIRLY SCATTERED IN NATURE.  MODELS ARE IN PRETTY GOOD AGREEMENT
SHOWING ANY THUNDERSTORMS NOT WASTING MUCH TIME MOVING THROUGH THE
CWA...AND KEPT ONLY A SMALL AREA OF LOW POPS IN THE NORTHEAST CORNER
OF THE CWA AFTER MIDNIGHT...WHICH COULD END UP BEING COMPLETELY
REMOVED ONCE WE SEE HOW THINGS ARE GOING TO PLAY OUT.

EXPECTING THAT AS THE CWA SITS ON THE BACKSIDE OF THIS LATEST
DISTURBANCE...THAT AT LEAST PART OF TUESDAY WILL BE DRY...AND
REMOVED POPS FOR THE FIRST HALF OF THE DAY.  THE UNSETTLED WEATHER
PATTERN REMAINS...WITH ANOTHER UPPER LEVEL WAVE STARTING TO APPROACH
THE AREA.  THROUGH THE DAYTIME HOURS ON TUESDAY...A FRONTAL BOUNDARY
WILL PUSH FURTHER SOUTH INTO THE CWA...BUT STALLS OUT...AND MODELS
IN PRETTY GOOD AGREEMENT SHOWING IT DRAPED ACROSS THE SOUTHEASTERN
HALF BY MID AFTERNOON.  WITH THIS NEXT WAVE MOVING IN...THIS SFC
BOUNDARY WILL PROVIDE A FOCUS FOR ANOTHER ROUND OF THUNDERSTORMS
DURING THE AFTERNOON AND EVENING HOURS...WITH STRONG/SEVERE
THUNDERSTORMS POSSIBLE ONCE AGAIN...AS INSTABILITY LOOKS TO BE
BETTER...BUT THE BETTER SHEAR REMAINS ON THE BACKSIDE OF THE
FRONT...SO THE OVERALL SEVERE COVERAGE IS A LITTLE UNCERTAIN. ONE
FACTOR THAT WILL PLAY A ROLE TOMORROW EVENING/NIGHT THAT IS NOT
QUITE THE ISSUE TONIGHT IS THE INCREASING LOW LEVEL JET.  ALONG THE
WITH THE SFC BOUNDARY THROUGH THE CWA...THE 850MB FRONT IS ALSO
MEANDERING THE AREA...AND THERE IS GOOD AGREEMENT SHOWING INCREASING
COVERAGE IN PRECIPITATION AS THE LOW LEVEL CONVERGENCE ACROSS THE
CWA RAMPS UP ACCOMPANYING THE INCREASING LLJ...WHICH LOOKS TO KEEP
PRECIPITATION GOING THROUGH MOST/IF NOT ALL OF THE OVERNIGHT HOURS.
NO SURPRISE THAT PW VALUES ARE IN THE 1-2 INCH RANGE IN THE SE...SO
COULD BE SOME LOCALLY HEAVY RAIN WITH THE STRONGER STORMS...AND IF
THESE STORMS TRAIN OVER THE SAME AREA...COULD LEAD TO SOME FLOODING
PROBLEMS.

.LONG TERM...WEDNESDAY THROUGH MONDAY. THE FOCUS THIS PERIOD IS
THUNDERSTORMS WEDNESDAY...FOLLOWED BY ANOTHER SURGE OF DRIER...
FALL-LIKE AIR THURSDAY AND FRIDAY.

WEDNESDAY IS AN INTERESTING DAY FOR THE AREA...AS THE CWFA WILL
LIKELY BE BATTLING CLOUDS IN SEVERAL AREAS THROUGHOUT THE
DAY...WHICH MAY SIGNIFICANTLY INFLUENCE CONVECTIVE TRENDS. SURFACE
LOW PRESSURE WILL DEEPEN IN NORTHWEST KANSAS...AND GRADUALLY WORK
EAST. AS UPPER LEVEL ENERGY APPROACHES FROM THE WEST...THE CWFA
SHOULD CATCH ISOLATED TO SCATTERED SHOWERS/THUNDERSTORMS FOR MUCH OF
THE DAY. IT/S NOT A RAIN-OUT BY ANY MEANS...BUT RAIN WILL BE AROUND
FOR MANY AREAS. INSTABILITY AND SHEAR WILL BE SUFFICIENT FOR SOME
SEVERE THUNDERSTORMS...PROBABLY FAVORING THE EASTERN HALF OF THE CWFA
OVER THE WEST. THINGS SHOULD BE WRAPPING UP GRADUALLY OVERNIGHT.

THE MAIN SURGE OF DRY AIR WILL COME ACROSS THE CWFA DURING THE DAY
THURSDAY...WILL RESULT IN DEWPOINTS IN THE 40S AND 50S BY EVENING.
AGREE WITH PREVIOUS FORECAST REGARDING HOLDING OUT OF THE FORECAST
SOME LINGERING SHOWERS WHICH SHOULD BE PRETTY NON-CONSEQUENTIAL IF
EVEN THERE AT ALL. LOOK FOR A COOL NIGHT THURSDAY NIGHT WITH A
PLEASANT...LIGHT WIND...DAY FRIDAY AND COMFORTABLE AFTERNOON HIGHS.

STUCK WITH THE DRY FORECAST THROUGH THE WEEKEND. RETURN FLOW AND
LOW/MID LEVEL WARM ADVECTION SATURDAY AFTERNOON/EVENING MAY STILL
RESULT IN SOME SHOWERS...BUT THE FOCUS WILL LIKELY BE EAST OF OUR
CWFA. THIS SCENARIO WILL NEED TO BE WATCHED FOR POSSIBLE INCLUSION
OF SMALL CHANCE OF SHOWERS/STORMS WITH SUBSEQUENT FORECASTS. MODELS
DEPICT VERY WARM H7 TEMPERATURES OF +14 TO 16 DEGREES...AND WITH THE
ABSENCE OF HIGH HEAT OR OBVIOUS TRIGGER TO BREAK THE CAP..THINGS
SHOULD BE DRY SUNDAY/LABOR DAY.

&&

.AVIATION...18Z TAF. VFR CONDITIONS EXPECTED FOR THIS TAF
PERIOD...WITH WINDS CONTINUING TO BE THE MAIN CONCERN EARLY ON.
LITTLE CHANGE EXPECTED THE REST OF THIS AFTERNOON WITH THE
SOUTHERLY WINDS...WHICH ARE CURRENTLY SUSTAINED NEAR 25 MPH WITH
GUSTS NEAR 35 MPH...WITH THE PRESSURE GRADIENT REMAINING TIGHT
AND STRONGER WINDS ALOFT MIXING DOWN TO THE SFC. WINDS WILL STAY
SOUTHERLY THROUGH TONIGHT AND INTO EARLY TOMORROW MORNING...BUT A
SFC COLD FRONT WILL BEGIN TO APPROACH THE TERMINAL TOWARD THE END
OF THE TAF PERIOD...BRINGING MORE VARIABLE WINDS...WHICH WILL
EVENTUALLY BECOME NORTHWESTERLY TOMORROW AFTERNOON. AS FAR AS
PRECIPITATION CHANCES GO THIS AFTERNOON/EARLY EVENING...AN UPPER
LEVEL SHORTWAVE DISTURBANCE WILL CONTINUE PUSHING OUT OF THE
ROCKIES...BUT THE BULK OF THE RESULTING ACTIVITY IS EXPECTED TO
REMAIN TO THE WEST AND NORTH OF THE TERMINAL...SO JUST KEPT
MENTION AT VC/CB FOR NOW. WILL MAKE ANY ADJUSTMENTS THAT MAY BE
NEEDED ONCE CONVECTION GETS GOING...BUT AT THIS POINT JUST NOT
OVERLY CONFIDENT IN SEEING AN IMPACT AT THE TERMINAL.

&&

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

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE HASTINGS NE
338 PM CDT MON AUG 30 2010

KSZ005>007-017>019-NEZ039>041-046>049-060>064-072>077-082>087-
311200-
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-
338 PM CDT MON AUG 30 2010

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

.DAY ONE...THIS AFTERNOON AND TONIGHT.

A FEW STRONG TO SEVERE THUNDERSTORMS REMAIN POSSIBLE LATE THIS
AFTERNOON INTO THE EVENING ACROSS THE OUTLOOK AREA. THE BEST
CHANCES FOR SEVERE WEATHER WILL REMAIN GENERALLY ALONG AND
NORTHWEST OF A LINE FROM GREELEY...TO GIBBON...TO ATLANTA IN SOUTH
CENTRAL NEBRASKA. DAMAGING WIND GUSTS TO 60 MPH WILL BE THE
PRIMARY CONCERN...THOUGH A COUPLE STORMS COULD PRODUCE HAIL TO THE
SIZE OF QUARTERS.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY.

THE CHANCE FOR THUNDERSTORMS CONTINUES ACROSS PORTIONS OF THE
OUTLOOK AREA ON TUESDAY. SOME OF THE STORMS COULD BE STRONG TO
SEVERE...ESPECIALLY DURING THE LATE AFTERNOON AND EVENING
HOURS...WITH THE BEST CHANCES GENERALLY SOUTHEAST OF A LINE FROM
GREELEY TO ELWOOD NEBRASKA. LOCALLY HEAVY RAINFALL AND FLOODING
MAY BE ANOTHER CONCERN FROM THE STORMS TUESDAY AFTERNOON INTO
TUESDAY NIGHT.

SCATTERED THUNDERSTORMS ARE EXPECTED ON WEDNESDAY AND
WEDNESDAY NIGHT ACROSS THE OUTLOOK AREA. MODERATE INSTABILITY
AND FAVORABLE WIND FIELDS WILL YIELD SOME STRONG TO SEVERE
THUNDERSTORMS...ESPECIALLY DURING THE AFTERNOON AND EARLY EVENING
HOURS. LARGE HAIL...DAMAGING WINDS...AND HEAVY RAIN IN EXCESS OF
1 TO 2 INCHES CAUSING LOCALIZED FLOODING ISSUES WILL BE THE PRIMARY
HAZARDS.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION COULD BE NEEDED THIS AFTERNOON AND
EVENING...MAINLY NORTHWEST OF A LINE FROM GREELEY...TO GIBBON...TO
ATLANTA IN SOUTH CENTRAL NEBRASKA.

&&

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

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE HASTINGS NE
314 PM CDT MON AUG 30 2010

NEZ072-082-302100-
FURNAS NE-GOSPER NE-
314 PM CDT MON AUG 30 2010

...SIGNIFICANT WEATHER ADVISORY FOR FURNAS AND GOSPER COUNTIES UNTIL
400 PM CDT...

AT 309 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING
STRONG THUNDERSTORMS ALONG A LINE EXTENDING FROM 6 MILES NORTHWEST OF
BARTLEY TO 7 MILES SOUTHEAST OF WILSONVILLE...AND MOVING NORTHEAST AT
45 MPH.

WIND GUSTS UP TO 50 MPH ARE EXPECTED WITH THESE STORMS.

THESE STORMS WILL BE NEAR...
HENDLEY AROUND 320 PM CDT.
HOLBROOK AND BEAVER CITY AROUND 325 PM CDT.
HOLLINGER AND ARAPAHOE AROUND 330 PM CDT.
EDISON AROUND 335 PM CDT.
OXFORD AROUND 345 PM CDT.
ELWOOD AROUND 350 PM CDT.
SMITHFIELD AROUND 355 PM CDT.
JOHNSON LAKE AROUND 400 PM CDT.

THESE STORMS MAY INTENSIFY...SO BE CERTAIN TO MONITOR LOCAL RADIO AND
TV STATIONS...AS WELL AS LOCAL CABLE TV OUTLETS... FOR ADDITIONAL
INFORMATION AND POSSIBLE WARNINGS FROM THE NATIONAL WEATHER SERVICE.

LAT...LON 4033 10020 4035 10009 4045 10008 4045 9998
      4069 9998 4068 9967 4034 9964 4033 9963
      4019 9963 3999 9991 4000 10006 4012 10020
TIME...MOT...LOC 2014Z 222DEG 39KT 4037 10032 4007 9997

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE HASTINGS NE
329 PM CDT MON AUG 30 2010

NEZ060-302130-
DAWSON NE-
329 PM CDT MON AUG 30 2010

...SIGNIFICANT WEATHER ADVISORY FOR DAWSON COUNTY UNTIL 430 PM CDT...

AT 327 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING
STRONG THUNDERSTORMS ALONG A LINE EXTENDING FROM 19 MILES SOUTHWEST
OF GOTHENBURG TO 11 MILES NORTH OF HOLBROOK...AND MOVING NORTHEAST AT
50 MPH.

WIND GUSTS UP TO 50 MPH ARE EXPECTED WITH THESE STORMS.

THESE STORMS WILL BE NEAR...
WILLOW ISLAND...GOTHENBURG AND COZAD AROUND 350 PM CDT.
LEXINGTON AROUND 355 PM CDT.
SUMNER AND EDDYVILLE AROUND 415 PM CDT.

THIS INCLUDES INTERSTATE 80 BETWEEN MILE MARKERS 209 AND 242.

THESE STORMS MAY INTENSIFY...AND A SEVERE THUNDERSTORM WATCH IS IN
EFFECT FOR THIS AREA. BE CERTAIN TO MONITOR LOCAL RADIO AND TV
STATIONS...AS WELL AS LOCAL CABLE TV OUTLETS...FOR ADDITIONAL
INFORMATION AND POSSIBLE WARNINGS FROM THE NATIONAL WEATHER SERVICE.

LAT...LON 4105 10021 4104 9943 4069 9966 4069 9995
      4072 10022
TIME...MOT...LOC 2029Z 224DEG 45KT 4079 10044 4048 10000