Damaging Wind in Nebraska, June 26, 2009

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
312 PM CDT FRI JUN 26 2009

.DISCUSSION...

THE CHANCE FOR TSTMS...POSSIBLY SEVERE...IS THE PRIMARY CONCERN IN
THE SHORT TERM. KEPT SOME CHANCE FOR PCPN IN THE GRIDS THROUGH SAT
AFTN...THEN WENT WITH POPS 14 OR LESS FROM SAT NGT INTO WED. WATER
VAPOR IMAGERY SHOWED SHORTWAVE ENERGY OVER THE ROCKIES...TRACKING
NEWD. MOST IMPRESSIVE FEATURE WAS OVER SWRN UT...BUT SEVERAL OTHER
PIECES WERE LOCATED FROM ID AND WY INTO CO AND NM. ALL OF THIS WAS
IN AN AREA WITH 30 TO 70 METER 12 HOUR HEIGHT FALLS AT 500 MB AT
12Z. THE WAVE MOVING THROUGH NOW...ASSOCIATED WITH SHOWERS AND TSTMS
ACROSS OUR NRN ZNS SHOULD LIFT NEWD OUT OF THE AREA THIS EVENING.
CONVECTION SHOULD INCREASE OVER THE WRN HIGH PLAINS. 12Z 4 KM
WRF-NMM SUGGESTS THAT THINGS WILL EVOLVE ABOUT LIKE THE PREVIOUS
FORECAST INDICATED...SO DID NOT MAKE MANY CHANGES.

COLD FRONT IS EXPECTED TO PUSH INTO THE AREA FROM THE NW LATE TNGT
AND MORESO DURING THE DAY SAT. MODELS SUGGEST A FAIRLY STRONG CAP
WILL REMAIN IN PLACE ACROSS OUR SRN ZONES TNGT...SO KEPT POPS LOW
THERE. NRN ZONES SEEM MORE IN LINE FOR ACTIVITY MOVING IN FROM THE
W OR SW LATER TONIGHT. ELEVATED CAPE IS NOT OVERLY IMPRESSIVE...
BUT IF STRONG STORMS OCCUR IT APPEARS THERE WILL BE SOME POTENTIAL
FOR DAMAGING WINDS WITH INVERTED V TYPE SOUNDINGS. THAT WILL BE
SOMEWHAT DEPENDANT ON HOW STRONG OF A LOW LEVEL INVERSION DEVELOPS
WHICH COULD HINDER WINDS MIXING DOWN TO THE SURFACE. POTENTIAL FOR
A BOW ECHO LOOKS HIGHER ACROSS ERN SD.

CURRENT LARGE SCALE PATTERN WITH A 500 MB RIDGE ACROSS THE PLAINS
MODIFIES SOME OVER THE WEEKEND. FLOW IN OUR AREA WILL TURN TO THE
W AND THEN NW SATURDAY NIGHT...ALLOWING WEAK HIGH PRESSURE AT THE
SURFACE TO MOVE IN ALONG WITH DRIER AIR. THAT WEAK RIDGING SHOULD
MOVE SLOWLY EWD NEXT WEEK...WITH LOW LEVEL FLOW TURNING TO THE SE
AND THEN S. GENERALLY PREFERRED THE ECMWF MODEL OUTPUT OVER THE
GFS. THE EC HAS A CLOSED 500 MB LOW MOVING SEWD ACROSS THE GREAT
LAKES REGION MON/TUE/WED...WHILE A RIDGE DEVELOPS AGAIN OVER THE
ROCKIES AND BUILDS EWD INTO THE PLAINS. THAT RIDGE SHOULD BREAK
DOWN LATE NEXT WEEK IN OUR AREA...BUT REMAIN IN PLACE ACROSS THE
SRN PLAINS.

&&

.AVIATION...
FOR TAF SITES KOFK/KOMA/KLNK VALID THROUGH 27/18Z.

VFR CONDITIONS EXPECTED AT ALL THREE SITES THROUGH THE PERIOD.
REMNANTS OF EARLIER MCS OVER CENTRAL NEBRASKA EXPECTED TO CONTINUE
TO GRADUALLY DISSIPATE THROUGH ABOUT 20Z WITH SOME RW- AT KOFK.
POTENTIAL FOR ADDITIONAL CONVECTION DEVELOPING UPSTREAM AFTER 00Z
BUT NO MENTION AT THIS TIME DUE TO UNCERTAINTY IN TIMING.

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&

DISCUSSION...MILLER
AVIATION...FOBERT

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE OMAHA/VALLEY NE
529 PM CDT FRI JUN 26 2009

IAZ043-055-056-069-079-080-090-091-NEZ011-012-015>018-030>034-
042>045-050>053-065>068-078-088>093-271230-
MONONA-HARRISON-SHELBY-POTTAWATTAMIE-MILLS-MONTGOMERY-FREMONT-
PAGE-KNOX-CEDAR-THURSTON-ANTELOPE-PIERCE-WAYNE-BOONE-MADISON-
STANTON-CUMING-BURT-PLATTE-COLFAX-DODGE-WASHINGTON-BUTLER-
SAUNDERS-DOUGLAS-SARPY-SEWARD-LANCASTER-CASS-OTOE-SALINE-
JEFFERSON-GAGE-JOHNSON-NEMAHA-PAWNEE-RICHARDSON-
529 PM CDT FRI JUN 26 2009

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHWEST
IOWA...WEST CENTRAL IOWA...EAST CENTRAL NEBRASKA...NORTHEAST
NEBRASKA AND SOUTHEAST NEBRASKA.

.DAY ONE...TONIGHT AND SATURDAY

THERE IS A CHANCE OF THUNDERSTORMS OVERNIGHT GENERALLY ALONG AND
NORTH OF HIGHWAY 30. STORMS LATER TONIGHT HAVE THE POTENTIAL FOR
DAMAGING WINDS...LARGE HAIL AND VERY HEAVY RAIN.

THUNDERSTORMS WILL DEVELOP WEST AND NORTH OF THE REGION ALONG A
COLD FRONT OR IN THE AXIS OF A LOW LEVEL JET LATER THIS EVENING.
THIS ACTIVITY COULD MOVE OR DEVELOP SOUTHEAST INTO THE REGION
TONIGHT.

.DAYS TWO THROUGH SEVEN...SATURDAY NIGHT THROUGH FRIDAY

THUNDERSTORMS COULD LINGER INTO SATURDAY OVER SOUTHEAST NEBRASKA
AND SOUTHWEST IOWA. EARLY MORNING THUNDERSTORMS COULD STILL
CONTAIN GUSTY WINDS AS A COLD FRONT PUSHES INTO FAR SOUTHEAST
NEBRASKA AND SOUTHWEST IOWA. AT THIS TIME IT APPEARS THE FRONT
WILL PUSH THROUGH FAR SOUTHEAST NEBRASKA AND SOUTHWEST IOWA BY MID
AFTERNOON...IF IT SLOWS DOWN AND ADDITIONAL THUNDERSTORMS DEVELOP
ALONG IT IN THE LATE AFTERNOON HOURS...STORMS COULD BECOME SEVERE
AND PRODUCE DAMAGING WINDS ALONG WITH LARGE HAIL.

THE NEXT CHANCE OF THUNDERSTORMS OVER THE AREA IS WEDNESDAY NIGHT.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED LATE TONIGHT IN PARTS OF
NORTHEAST NEBRASKA...MAINLY NORTH OF A COLUMBUS TO TEKAMAH LINE.

KERN