Severe Thunderstorm Warning 209, NWS North Platte, NE

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
327 PM CDT FRI JUL 2 2010

.SYNOPSIS...
AT H5 TROUGH INTO PACIFIC NORTHWEST WITH STRONG RIDGE THROUGH
MISSISSIPPI VALLEY. REMNANTS OF ALEX OVER TEXAS.

&&

.DISCUSSION...
MODELS IN GOOD AGREEMENT IN NEAR TERM . HAVE GOOD CONFIDENCE IN
THE NEAR TERM FORECAST. ALTHOUGH BREEZY...ADVISORY CRITERIA NEVER
DEVELOPED THIS AFTERNOON AND WILL LET ADVISORY GO AT ISSUANCE
TIME. CONVECTION OVER THE EASTERN PLAINS OF WYOMING AND COLORADO
SHOULD MAKE INROADS INTO WESTERN NEBRASKA THIS EVENING. ATMOSPHERE
CONTINUES TO DESTABILIZE WITH LARGE CU FIELD OVER MOST OF SOUTHERN
NEBRASKA. WAVE MOVING THOUGH THE CENTRAL COLORADO ROCKIES AS SEEN
IN WV. COOL FRONT WILL DROP INTO NORTHWEST NEBRASKA BY 12Z
SATURDAY MORNING AND BE THE FOCUS FOR THUNDERSTORM DEVELOPMENT ON
SATURDAY. MOISTURE CONTINUES TO POOL AHEAD OF THIS SYSTEM IN
STRONG SOUTHERLY FLOW. SB CAPES AROUND 2000 JOULES/KG ON SATURDAY.
WILL BE SOME CHANCE FOR HAIL EARLY ON BUT AS THE FRONT MOVES
SLOWLY EAST ACROSS THE SANDHILLS INTO THE EVENING DYNAMICS WILL BE
GEARED MORE TOWARDS EFFICIENT RAIN PRODUCERS. STORM MOTION WILL BE
TO THE EAST NORTHEAST AROUND 10 TO 15 MPH. PWATS AROUND 1 INCH FFG
1 HR AROUND 2 INCHES AND 3 HR AROUND 2 TO 3 INCHES. RIVERS OVER
THE AREA HAVE DROPPED. FRONT TO STALL OUT OVER KS NE BORDER SUNDAY
AFTERNOON WITH CONVECTION FOCUSED ALONG THE BOUNDARY. HAVE COOLED
TEMPERATURES BACK SOME WITH CLOUD COVER AND RAIN CHANCES FOR
WESTERN NEBRASKA ON SUNDAY. SUNDAY AFTERNOON INTO MONDAY MORNING
RAIN WILL TAPER DOWN. MODELS DIFFER SOME ON PLACEMENT OF FRONT
FURTHER INTO KANSAS MONDAY. HAVE USED A BLEND FOR THE FORECAST.
SECONDARY FRONT SLIDES ACROSS THE AREA TUESDAY. MAIN ENERGY
APPEARS TO BE NORTH AND HAVE CONTINUED SCHC POPS THROUGH THE
PERIOD. UPPER RIDGE OVER THE SOUTHEASTERN CONUS BUILDS WEST INTO
THE SOUTHERN PLAINS THROUGH THE EXTENDED PERIOD. THIS WILL PUT THE
FORECAST AREA IN A MORE ACTIVE PATTERN.

&&

.AVIATION...

VISUAL FLIGHT RULES WILL CONTINUE THROUGH 06Z THEN DETERIORATING
CEILINGS AS BOUNDARY LAYER MOISTURE DEEPENS. HOW LOW CEILINGS WILL
GO IS THE MAIN CHALLENGE AS CEILINGS DROPPED TO OVC017 FEET THIS
MORNING AND IS EXPECTED TO GO LOWER AND BE MORE EXTENSIVE SATURDAY
MORNING. FOR NOW CEILINGS DROPPED BEYOND 06Z TO MARGINAL VISUAL
FLIGHT RULES FOR TERMINALS KLBF AND KVTN THAT SHOULD LIFT AROUND
17Z. ISOLATED THUNDERSTORMS MAY DEVELOP EAST OF THE PANHANDLE THIS
EVENING WHERE KVTN IS SEEN AS A BETTER POTENTIAL AS THE CAP WEAKENS
THIS AFTERNOON. THE STORMS WILL BE HIGH BASED WITH STRONG WIND GUSTS
POSSIBLE WHILE THEY MOVE ACROSS.

&&

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

&&

SHORT TERM/EXTENDED...POWER
AVIATION...KECK

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE NORTH PLATTE NE
228 PM CDT FRI JUL 2 2010

NEZ004>010-022>029-035>038-056>059-069>071-094-031000-
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-
228 PM CDT FRI JUL 2 2010 /128 PM MDT FRI JUL 2 2010/

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

.DAY ONE...TONIGHT.

THERE IS A SLIGHT RISK FOR SEVERE THUNDERSTORM DEVELOPMENT LATE
THIS AFTERNOON AND TONIGHT IN THE WEST. THE GREATEST IMPACT WILL
BE WEST OF A LINE FROM AINSWORTH...TO NORTH PLATTE AND ENDERS
WHERE ISOLATED TO SCATTERED THUNDERSTORMS MAY DEVELOP NEAR THE
DRYLINE. THE GREATEST THREAT WILL BE FOR DAMAGING WINDS AS AN
UPPER LEVEL DISTURBANCE MOVES NORTHEAST THIS EVENING.

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

SATURDAY THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN AREAS
NORTH OF INTERSTATE 80 AND GENERALLY EAST OF HIGHWAY 61... AS A
COLD FRONT MOVES OVER WESTERN AND NORTH CENTRAL NEBRASKA. THE MAIN
THREATS WITH THUNDERSTORMS THAT DEVELOP ALONG THE FRONT WILL BE
LARGE HAIL AND DAMAGING THUNDERSTORM WINDS. IN ADDITION... HEAVY
RAIN IS ALSO POSSIBLE.

ON THE 4TH OF JULY THERE IS A CHANCE FOR THUNDERSTORMS AGAIN
AS A COLD FRONT MOVES SLOWLY SOUTHEAST TO NEAR THE KANSAS AND
NEBRASKA STATELINE BY EVENING. THE EVENTUAL PLACEMENT OF THE FRONT SUNDAY
WILL INFLUENCE THE CHANCE FOR THUNDERSTORMS AND THE POTENTIAL FOR
HEAVY RAINFALL.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS POSSIBLE ACROSS THE WEST THROUGH TONIGHT.

&&

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

KECK