000
FXUS63 KLBF 181727
AFDLBF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
1227 PM CDT TUE JUN 18 2013

.SYNOPSIS...
ISSUED AT 317 AM CDT TUE JUN 18 2013

WIND AND DEWPOINT ANALYSIS OF THE 08Z MSL SHOWS A BOUNDARY ACROSS
NORTHERN KANSAS WITH MOISTURE CONVERGENCE ALONG IT. ANOTHER WIND
SHIFT LINE WAS ACROSS NORTHERN NEBRASKA. RADAR SHOWED A MESOSCALE
VORTEX OVER THE SOUTHEAST NEBRASKA PANHANDLE WITH A BOUNDARY ACROSS
SOUTHWEST NEBRASKA. THERE WAS ALSO A LINE OF THUNDERSTORMS BETWEEN
MULLEN AND MCCOOK IN WESTERN NEBRASKA.

&&

.UPDATE...
ISSUED AT 937 AM CDT TUE JUN 18 2013

A BRIEF MID-MORNING UPDATE TO ACCOUNT FOR THE ISOLATED TO
SCATTERED WEAK CONVECTION ACROSS NORTH CENTRAL NEBRASKA. THE
CONVECTION IS ASSOCIATED WITH ENHANCED LIFT FROM A MID-LEVEL
SHORTWAVE TROUGH WHICH IS DEPARTING TO THE EAST OVER SOUTHERN
MINNESOTA. DO NOT EXPECT THIS ACTIVITY TO LAST MUCH PAST THIS
MORNING AS THE LIFT FROM THE AREA CONTINUES EAST. QPF AMOUNTS
SHOULD REMAIN LIGHT...WITH A TENTH TO A QUARTER OF AN INCH PER
HOUR POSSIBLE UNDER THE HEAVIEST OF CELLS. OTHERWISE THE FORECAST
REMAINS ON TRACK.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 317 AM CDT TUE JUN 18 2013

THE FORECAST CHALLENGE TODAY...AS IT HAS BEEN FOR THE LAST SEVERAL
DAYS...IS THE TIME AND LOCATION OF CONVECTIVE INITIATION. THERE ARE
SEVERAL AREAS OF INTEREST ON THE HIGH PLAINS INCLUDING THE
CONVECTIVE VORTEX...OUTFLOW FROM THE CURRENT CONVECTION AND THE WIND
SHIFT BOUNDARY ACROSS NORTHERN KANSAS. THE RAP13...NAM12 AND THE GFS
SEEM TO BE FAVORING THE OUTFLOWS ACROSS WESTERN NEBRASKA WITH
CONVECTIVE INITIATION WEST AND SOUTH OF A VALENTINE-NORTH
PLATTE-BROKEN BOW LINE THIS AFTERNOON...BUT THEY RANGE WIDELY ON THE
TIMING THIS AFTERNOON OR EARLY EVENING AND THE EVENTUAL COVERAGE
LATER IN THE EVENING. THE NET RESULT IS THAT CONFIDENCE IS NOT HIGH
WITH ANY ONE SOLUTION.

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 317 AM CDT TUE JUN 18 2013

WARMING TEMPERATURES AND PRECIPITATION CHANCES HEADLINE THE
EXTENDED PERIODS THROUGH EARLY NEXT WEEK.

SOUTHWEST FLOW ALOFT TO PREVAIL STARTING OFF THE EXTENDED
FORECAST. AN UPPER LEVEL LOW AND ASSOCIATED TROUGH WILL BEGIN IT/S
ADVANCE ON THE PACIFIC NORTHWEST...FORCING AN UPPER RIDGE EAST
ACROSS THE GREAT PLAINS. BUILDING HEIGHTS AND INCREASING SOUTHERLY
COMPONENT OF THE LOWER TROPOSPHERIC FLOW WILL AID IN WARMING
TEMPERATURES BACK WELL INTO THE 80S FOR ALL LOCATIONS ACROSS
WESTERN AND NORTH CENTRAL NEBRASKA WEDNESDAY AFTERNOON...WITH THE
POSSIBILITY OF 90S RETURNING ACROSS FAR SOUTHWEST NEBRASKA.
WARMING TEMPERATURES ALOFT SHOULD LIMIT THE CONVECTION CHANCES
ACROSS WESTERN NEBRASKA...BUT SEVERAL OPERATIONAL MODELS ARE
PICKING UP ON CONVECTION DEVELOPING OVER THE EASTERN HALF OF THE
CWA BY EARLY EVENING...AND POSSIBLY CONTINUING WELL INTO THE
OVERNIGHT AS A LOW LEVEL JET TARGETS THE CENTRAL PLAINS. WILL
CONTINUE LOW END CHANCE POPS FOR LOCATIONS ALONG AND EAST OF
HIGHWAY 83 FROM WEDNESDAY EVENING UNTIL 12Z THURSDAY. WARMING
CONTINUES FOR THURSDAY WITH MOST LOCATIONS IN THE MID TO UPPER
80S...AND ONCE AGAIN LOW 90S FOR LOCATIONS SOUTH OF THE INTERSTATE
80 CORRIDOR. WILL KEEP THURSDAY DRY AS MOST LOCATIONS SHOULD
REMAIN FAIRLY CAPPED WITH STRONG WARMING ALOFT EXPECTED. THE EC IS
ADVERTISING A SUBTLE PERTURBATION WHICH MAY SPARK OFF CONVECTION
ACROSS NORTHWESTERN NEBRASKA OVERNIGHT. CONFIDENCE IN
PRECIPITATION LATE THURSDAY/EARLY FRIDAY IS LOW AT THIS TIME...BUT
WILL MAINTAIN A SLIGHT CHANCE ACROSS OUR NORTH. HIGHS CONTINUE TO
WARM FRIDAY IN ADVANCE OF A WEAK COLD FRONT EXPECTED TO ARRIVE
EARLY SATURDAY. WIDESPREAD 90S ARE ANTICIPATED.

FOR LATE FRIDAY AND BEYOND.  PACIFIC NORTHWEST UPPER LOW WILL
RELUCTANTLY WORK EAST ACROSS THE NORTHERN ROCKIES TOWARD THE
NORTHERN HIGH PLAINS.  THE REGION WILL REMAIN UNDER THE INFLUENCE OF
SOUTHWESTERLY FLOW ALOFT AS THE TROUGH BEGINS TO BREAKDOWN/FLATTEN
THE PLAINS UPPER RIDGE.  WITH THE PRESENCE OF A FRONTAL BOUNDARY
WITHIN THE REGION...STORM CHANCES WILL CONTINUE THROUGH THE UPCOMING
WEEKEND.  CONFIDENCE IN WEEKEND CONVECTION IS STILL RATHER LOW...SO
WILL CAP THE ALLBLEND PROCEDURE GENERATED POPS AT 35 PERCENT OR LESS
THROUGH THE WEEKEND...AND LEAVE THE GREATEST CHANCES DURING THE
EVENING/OVERNIGHT HOURS.  TEMPERATURES LOOK TO COOL A FEW DEGREES
FOR THE WEEKEND...BUT WARM ONCE AGAIN EARLY NEXT WEEK AS STRONG
WARMING OCCURS UNDER THE INFLUENCE OF CONTINUED SOUTHWESTERLY FLOW
ALOFT.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1226 PM CDT TUE JUN 18 2013

FORECAST CONFIDENCE REGARDING CONVECTION POTENTIAL LATER THIS
AFTERNOON/EVENING REMAINS LOW AS THERE IS LITTLE CONSENSUS
AMONG THE SHORT RANGE MODELS.  HOWEVER MOST PROJECTIONS INDICATE
THUNDERSTORM DEVELOPMENT THIS AFTERNOON OFF THE HIGHER
TERRAIN OF EASTERN COLORADO/WYOMING...WITH SOME OF THIS ACTIVITY
SPREADING EAST OVERNIGHT.  ADDITIONAL THUNDERSTORM DEVELOPMENT IS
POSSIBLE ALONG/NEAR ANY RESIDUAL BOUNDARY LEFT OVER FROM LAST NIGHTS
STORMS AS WELL.  GIVEN THE UNCERTAINTY IN TIMING AND LOCATION OF THE
POTENTIAL CONVECTION...WE WILL NOT INCLUDE ANY MENTION IN THE
OFFICIAL TAF FORECAST FOR VTN OR LBF AT THIS TIME...AND UPDATE WHEN
CONFIDENCE IS HIGHER.


&&

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

$$

UPDATE...JACOBS
SYNOPSIS...SPRINGER
SHORT TERM...SPRINGER
LONG TERM...JACOBS
AVIATION...JACOBS