Severe Thunderstorm Warning 407, NWS North Platte, NE

000 
WWUS53 KLBF 072357
SVSLBF

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE NORTH PLATTE NE
557 PM MDT MON SEP 7 2009

NEC005-069-075-161-080030-
/O.CON.KLBF.SV.W.0407.000000T0000Z-090908T0030Z/
ARTHUR NE-GARDEN NE-GRANT NE-SHERIDAN NE-
557 PM MDT MON SEP 7 2009

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 630 PM MDT
FOR SOUTHEASTERN SHERIDAN...WESTERN GRANT...NORTHERN GARDEN AND
WESTERN ARTHUR COUNTIES...

AT 555 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A LINE OF SEVERE THUNDERSTORMS CAPABLE OF PRODUCING DAMAGING
WINDS IN EXCESS OF 60 MPH.  THESE STORMS WERE LOCATED ALONG A LINE
EXTENDING FROM KINCAID LAKE TO CRESCENT LAKE NWR...OR ALONG A LINE
EXTENDING FROM 37 MILES EAST OF ALLIANCE TO 18 MILES NORTH OF
OSHKOSH...MOVING EAST AT 10 MPH.

SEVERE THUNDERSTORMS WILL BE NEAR...
  BRITTON LAKE BY 605 PM MDT...
  KINCAID LAKE BY 620 PM MDT...
  BINGHAM BY 625 PM MDT...
  DOMINICK LAKE...6 MILES WEST OF ASHBY AND 8 MILES NORTHWEST OF
  SWEDE LAKE BY 630 PM MDT...

LAT...LON 4207 10245 4205 10203 4206 10182 4146 10177
      4149 10264
TIME...MOT...LOC 2357Z 269DEG 9KT 4200 10216 4167 10236

$$

BUTTLER

000 
WWUS53 KLBF 080016
SVSLBF

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE NORTH PLATTE NE
616 PM MDT MON SEP 7 2009

NEC005-069-075-161-080026-
/O.CAN.KLBF.SV.W.0407.000000T0000Z-090908T0030Z/
ARTHUR NE-GARDEN NE-GRANT NE-SHERIDAN NE-
616 PM MDT MON SEP 7 2009

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN SHERIDAN...
WESTERN GRANT...NORTHERN GARDEN AND WESTERN ARTHUR COUNTIES IS
CANCELLED...

THE THUNDERSTORMS WHICH PROMPTED THE WARNING HAD WEAKENED AND NO 
LONGER POSED A SEVERE THREAT TO THE WARNED AREA.

LAT...LON 4207 10245 4205 10203 4206 10182 4146 10177
      4149 10264
TIME...MOT...LOC 0016Z 269DEG 9KT 4200 10210 4167 10230

$$

BUTTLER

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
310 PM CDT MON SEP 7 2009

.SHORT TERM DISCUSSION (TONIGHT THROUGH WEDNESDAY).

LATE AFTERNOON TSTMS MIGRATING FROM SERN WY AND NRN CO INTO THE WRN
PNHDL. THERE WILL BE ISOLATED EVENING TSTMS POSSIBLE OVER MOST AREAS
SOUTH OF A VTN THROUGH BARTLETT LINE. NO SEVERE EXPECTED HOWEVER DUE
TO WEAK DEEP LAYER WIND SHEAR. STRATUS TO AGAIN DEVELOP AFTER
MIDNIGHT...THIS TIME EXPECTED ACROSS NORTHEASTERN HALF OF FORECAST
AREA. LBF AND EVEN VTN SHOULD BE WEST OF STRATUS...ALTHOUGH SOME
PATCHY FOG POSSIBLE. WINDS WILL KEEP BOUNDARY LAYER MIXED AND LOW
VSBYS NOT FORECAST. OVERNIGHT LOWS AGAIN ON THE MILD SIDE WITH MOST
LOWS IN THE LOWER 60S.

TUESDAY/TUESDAY NIGHT...UPPER TROUGH APPROACHING FROM THE WEST WILL
BRING A SFC TROUGH/WEAK FRONT INTO THE NORTHWEST DURING THE AFTN.
SHOWERS AND STORMS SHOULD DEVELOP QUITE EASILY ALONG THE FRONT BY
AROUND 20Z AS H7-H5 LAPSE ARE QUITE STEEP AT 8.0-8.5 C/KM. WITH AFTN
HIGHS FROM 83 TO 89...SB CAPES BY LATE AFTN TO RANGE FROM 1500-2500
J/KG. MOISTURE IS IN PLACE AHEAD OF THE SURFACE FRONT/TROUGH WITH
PRECIPITABLE WATER VALUES RANGING FROM 1.15 INCH IN THE WEST TO NEAR
1.50 INCH IN THE EAST. DEEP LAYER SHEAR WILL BE WEAK AOB 20KTS...SO
MULTICELLULAR PULSE STORMS FAVORED. CANNOT RULE OUT ISOLATED
SEVERE...WITH SOME POTENTIAL FOR DAMAGING DOWNBURST WINDS. BRIEF
HEAVY HEAVY RAINFALL WILL BE MOST COMMON WITH STORM MOTION EAST
SOUTHEAST AT ONLY 5 TO 10 KTS. RAIN CHCS NEAR 50 PERCENT MOST AREAS.

WEDNESDAY...LINGERING SHOWERS AND TSTMS WEDNESDAY MORNING BEHIND THE
FRONT WITH SFC HIGH PRESSURE BUILDING IN. COOLER YET PLEASANT WITH
HIGHS 74 TO 80.

&&

.LONG TERM DISCUSSION (WEDNESDAY NIGHT THROUGH MONDAY).

AS UPPER TROUGH APPROACHES THE DAKOTAS THURSDAY...A SURFACE
TROUGH/FRONT WILL ADVANCE ACROSS THE WESTERN DAKOTAS. HIGHS SHOULD
REBOUND TO 80-85. THEN...A COLD FRONT WILL MOVE ACROSS WRN NEBRASKA
THURSDAY NIGHT BRINGING A CHANCE FOR SHOWERS TO MOST OF THE AREA.
BETTER RAIN CHC MAY COME FRIDAY FROM LIFT JUST AHEAD OF UPPER
TROUGH. HIGHS FRIDAY NEAR 74.

GFS AND ECMWF IN AGREEMENT WITH AN UPPER LOW DROPPING INTO NORTH
DAKOTA FRIDAY AND EASTERN SOUTH DAKOTA SATURDAY. THEY THEN
DIVERGE...WITH THE 12Z GFS LIFTING THE LOW BACK NORTH INTO EASTERN
NORTH DAKOTA SUNDAY AND THE UPPER GREAT LAKES. THE ECMWF SOLUTION
KEEPS THE UPPER LOW CUTOFF INTO WESTERN NEBRASKA BEYOND DAY 7
(MONDAY). SHOWERS CHANCES IN THE FORECAST THROUGH ENTIRE EXTENDED TO
ACCOUNT FOR UPPER LOW AND ASSOCIATED SHOWERS. HIGHS MAINLY AROUND 70
AND LOWS MID TO UPPER 40S. REGARDING FROST POTENTIAL...CHCS APPEAR
LOW. IF GFS SOLUTION VERIFIES...COOL AND DRIER AIR COULD STILL BRING
FROST. WILL NEED TO MONITOR.
&&

.AVIATION...
MAINLY VFR CONDITIONS THIS EVENING...WILL DROP TO MVFR CONDITIONS AS
STRATUS IS EXPECTED TO REDEVELOP NEAR 11Z-12Z. A RETURN TO VFR
DURING THE MID MORNING HOURS SHOULD OCCUR. A TROF ALONG THE FRONT
RANGE OF THE ROCKIES WILL DRIFT EAST THIS EVENING WITH ISOLATED
THUNDERSTORMS DEVELOPING AHEAD OF THE TROF...OVER THE PANHANDLE INTO
WESTERN NEBRASKA. EXPECTED IMPACT TO TAF SITES IS LOW AT THIS TIME
AND WILL NOT MENTION AT THIS POINT. WILL AMEND IF CHANCE INCREASE
FOR EITHER TAF SITE.
&&

.LBF
WATCHES/WARNINGS/ADVISORIES...NONE.
&&

SHORT AND LONG TERM...ROBERG
AVIATION...MASEK

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE NORTH PLATTE NE
413 PM CDT MON SEP 7 2009

NEZ004>010-022>029-035>038-056>059-069>071-094-082115-
SHERIDAN-EASTERN CHERRY-KEYA PAHA-BOYD-BROWN-ROCK-HOLT-GARDEN-
GRANT-HOOKER-THOMAS-BLAINE-LOUP-GARFIELD-WHEELER-ARTHUR-MCPHERSON-
LOGAN-CUSTER-DEUEL-KEITH-PERKINS-LINCOLN-CHASE-HAYES-FRONTIER-
WESTERN CHERRY-
413 PM CDT MON SEP 7 2009 /313 PM MDT MON SEP 7 2009/

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

.DAY ONE...TONIGHT.

AN ISOLATED SEVERE THUNDERSTORM COULD DEVELOP ACROSS NORTHWEST
NEBRASKA THIS EVENING. LARGE HAIL IS THE MAIN CONCERN AS AN UPPER
DISTURBANCE MOVES ACROSS THE REGION. LOCALLY HEAVY RAINFALL IS
ALSO POSSIBLE WITH THE STORM WHICH IS EXPECTED TO DEVELOP WEST OF
HIGHWAY 83. A STRAY STRONG THUNDERSTORM IS ALSO POSSIBLE TO THE
EAST OF HIGHWAY 83 THIS EVENING.

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

SCATTERED THUNDERSTORMS CAN BE EXPECTED TO DEVELOP ACROSS THE
AREA ALONG A SLOW MOVING COLD FRONT LATE TUESDAY AFTERNOON AND
TUESDAY NIGHT. THERE IS A SLIGHT RISK FOR THE THUNDERSTORMS TO
BECOME SEVERE. THE MAIN AREA OF CONCERN IS ACROSS NORTHWEST AND
NORTH CENTRAL NEBRASKA...NORTH OF A LINE FROM OGALLALA TO BROKEN
BOW. LARGE HAIL AND INTENSE RAINFALL ARE POSSIBLE. STORMS WILL
MOVE EAST AND NORTHEAST AT 10 MPH PRODUCING LOCALLY VERY HEAVY
RAINFALL. THURSDAY INTO FRIDAY WILL BRING ANOTHER DISTURBANCE
ACROSS THE AREA. THUNDERSTORMS WILL BE POSSIBLE ACROSS ALL OF
WESTERN AND NORTH CENTRAL NEBRASKA.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL NOT BE NEEDED THROUGH TONIGHT.

&&

THIS PRODUCT IS NOW AVAILABLE...ALONG WITH OTHER WEATHER...
HYDROLOGICAL AND CLIMATOLOGICAL INFORMATION...AT
HTTP://WWW.WEATHER.GOV/NORTHPLATTE

MASEK