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000
FXUS63 KLBF 161741
AFDLBF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
1241 PM CDT SUN JUN 16 2013

.SYNOPSIS...
ISSUED AT 321 AM CDT SUN JUN 16 2013

HAND ANALYSIS OF THE 07Z MSL DATA SHOWED LOW PRESSURE CENTERED OVER
NORTHEAST NEW MEXICO WITH A WARM FRONT EXTENDING ACROSS THE OKLAHOMA
PANHANDLE ACROSS KANSAS AND EXTREME NORTHWEST MISSOURI TO NORTHEAST
IOWA. THOUGH IT WAS A LITTLE MORE DIFFICULT TO DISCERN BECAUSE OF
TERRAIN...THERE WAS A COLD FRONT EXTENDING FROM THAT LOW ACROSS NEW
MEXICO AND ARIZONA. ANOTHER BOUNDARY OR WEAK FRONT WAS DISCERNIBLE
FROM SOUTH CENTRAL NEBRASKA THROUGH NORTHWEST KANSAS TO SOUTHEAST
COLORADO AND YET ANOTHER BOUNDARY OR TROUGH ACROSS SOUTH
DAKOTA.

&&

.UPDATE...
ISSUED AT 1053 AM CDT SUN JUN 16 2013

FORECAST IS ON TRACK...WITH THUNDERSTORMS STILL ANTICIPATED THIS
AFTERNOON AND EVENING. ELEVATED CONVECTION CONTINUES TO MOVE EAST
ACROSS NORTH CENTRAL NEBRASKA...AND AN OUTFLOW BOUNDARY FROM THIS
CONVECTION IS EVIDENT IN OBS AND VISIBLE SATELLITE IMAGERY...AND
EXTENDS FROM FAR EASTERN SHERIDAN COUNTY SOUTHEAST THROUGH
CENTRAL LINCOLN COUNTY. SHORT TERM MODELS HOLD THIS BOUNDARY IN
PLACE AND DEVELOP CONVECTION ACROSS WESTERN CHERRY/EASTERN
SHERIDAN COUNTY BY MID AFTERNOON. THESE STORMS WILL THEN
DEVELOP/MOVE SOUTHEAST ALONG THE BOUNDARY INTO SOUTHWEST NEBRASKA.
OTHER STORMS MAY DEVELOP ALONG A DRY LINE ACROSS THE EASTERN
PORTIONS OF THE NEBRASKA PANHANDLE. SUPERCELLS ARE LIKELY WITH THE
INITIAL DEVELOPMENT ACROSS NORTHWEST NEBRASKA...TRANSITIONING TO A
FORWARD PROPAGATING MCS ACROSS SOUTHWEST NEBRASKA AND INTO KANSAS.

DESPITE WEAK LOW LEVEL FLOW...AT LEAST SOME TORNADO POTENTIAL WILL
BE POSSIBLE WITH THE INITIAL STORMS NEAR THE OUTFLOW BOUNDARY.
OTHERWISE MAINLY LARGE HAIL AND DAMAGING WINDS EXPECTED WITH ANY
SEVERE STORM.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 321 AM CDT SUN JUN 16 2013

SHORT RANGE PROJECTIONS SUCH AS THE NAM12...THE GEM REGIONAL AND THE
RAP13 SHOW A FRONT FORMING OVER THE NORTHERN HIGH PLAINS AND PUSHING
THROUGH NORTHWEST NEBRASKA LATE THIS MORNING. AT THE SAME TIME...
MOIST AIR IS EXPECTED TO LIFT UP OVER THE FRONT ACROSS THE CENTRAL
AND SOUTHERN PLAINS...LEAVING MOISTURE AVAILABLE FOR THE NORTHERN
FRONT TO GENERATE SCATTERED THUNDERSTORMS LATE THIS MORNING. BY
MIDDAY...THE MOST UNSTABLE CONDITIONS ARE LOCATED OVER CENTRAL AND
WESTERN NEBRASKA WITH SURFACE-BASED CONVECTIVE POTENTIAL ENERGY
EXCEEDING 4000J/KG AND 0-6KM BULK SHEAR OF 40-50KT. AS A RESULT...
OUR CONFIDENCE IS FAIRLY HIGH THAT SCATTERED THUNDERSTORMS WILL
DEVELOP BY EARLY AFTERNOON AND THERE IS POTENTIAL FOR LARGE HAIL
OVER A LARGE PART OF WESTERN AND NORTH CENTRAL NEBRASKA. THE
GREATEST POTENTIAL FOR LARGE HAIL IS EXPECTED TO BE IN CENTRAL AND
SOUTHWEST NEBRASKA. AS THE FRONT PUSHES ON THROUGH THIS EVENING...
THE CHANCES OF THUNDERSTORMS DIMINISH AS WELL.

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 321 AM CDT SUN JUN 16 2013

WEAK SURFACE HIGH PRESSURE WILL
BUILD SOUTH AND EAST ACROSS WESTERN NEBRASKA ON MONDAY...PROVIDING
FOR SLIGHTLY COOLER TEMPERATURES AND WEAK EASTERLY UPSLOPE WIND.
THE WEAK UPSLOPE FLOW SHOULD AID IN THE DEVELOPMENT OF ADDITIONAL
THUNDERSTORMS ACROSS SOUTHWEST NEBRASKA AND THE EASTERN PANHANDLE
DURING THE AFTERNOON HOURS.  STEEP LAPSE RATES WILL PROVIDE FOR A
MODERATELY UNSTABLE AIRMASS CAPABLE OF PRODUCING LARGE HAIL AND
GUSTY THUNDERSTORM WIND.  GIVEN QUASI-ZONAL FLOW IN THE STEERING
LEVELS...STORMS MAY EVOLVE SOUTHEAST ACROSS THE SOUTHERN SANDHILLS
AND SOUTHWEST NEBRASKA OVERNIGHT.  BUT GIVEN THE CONDITIONALITY OF
THUNDERSTORM DEVELOPMENT WILL CONTINUE TO LIMIT POPS AT 40 PERCENT
FOR NOW...BUT MAINTAIN THE GREATEST CHANCES FIRST ACROSS THE EASTERN
PANHANDLE DURING THE AFTERNOON HOURS...WITH THE FOCUS ANTICIPATED TO
SHIFT SOUTHEAST OVERNIGHT.  BEYOND MONDAY NIGHT THE UPPER LEVELS
BEGIN TO SLOWLY TRANSITION FROM QUASI-ZONAL TO SOUTHWESTERLY AS A
STRONG UPPER TROUGH BECOMES ESTABLISHED ACROSS THE PACIFIC NORTHWEST
AND FORCES A RIDGE OVER THE PLAINS.  PRECIPITATION CHANCES HOWEVER
WILL CONTINUE THROUGH THE UPCOMING WORK WEEK AS THE OPERATIONAL GFS
AND EC CONTINUE TO SUGGEST NUMEROUS SUBTLE PERTURBATIONS PASSING
WITHIN THE REGION.  PROXIMITY SOUNDINGS ACROSS THE FORECAST AREA
INDICATE SUFFICIENT INSTABILITY THROUGHOUT THE PERIOD WITH STEEP LOW
TO MID LEVEL LAPSE RATES.  DAILY/NIGHTLY THUNDERSTORM CHANCES ARE
CERTAINLY POSSIBLE ANY DAY THIS COMING WEEK...ESPECIALLY SINCE
TIMING OF THESE SMALL SCALE PERTURBATIONS IS DIFFICULT THIS FAR
OUT.  THE 16.00Z ALLBLEND PROCEDURE HAS CERTAINLY CAUGHT ON TO THE
POTENTIAL...AND PROVIDED SLIGHT CHANCE TO CHANCE POPS WITHIN EVERY
EXTENDED FORECAST PERIOD.  AT THIS JUNCTURE...CANNOT ARGUE AGAINST
THE PROCEDURE...ESPECIALLY GIVEN THE PROSPECTS OF MULTIPLE
PERTURBATIONS IMPACTING THE REGION.   CERTAINLY TIMING AND LOCATION
WILL BECOME BETTER APPARENT AS EACH PERTURBATION DRAWS CLOSER TO THE
CWA...BUT FOR NOW WILL ONLY SMOOTH THE GIVEN ALLBLEND OUTPUT AND
LIMIT POPS AT 35 PERCENT OR LESS.

TEMPERATURE WISE THROUGH THE COMING WORK WEEK...WITH BUILDING
HEIGHTS AND INCREASING SOUTHERLY FLOW ANTICIPATED...HIGHS WILL BEGIN
TO SLOWLY MODERATE WITH WIDESPREAD TEMPERATURES OF THE LOW TO MID
80S EXPECTED TUESDAY AND WEDNESDAY...AND POSSIBLY A RETURN TO THE
LOW 90S FOR SOUTHWEST NEBRASKA THURSDAY AND FRIDAY.  LOWS WILL
REMAIN SEASONAL TO SLIGHTLY ABOVE AVERAGE AND GREATLY DEPENDENT ON
ANY NOCTURNAL CLOUDS/PRECIPITATION.  FOR NOW...WILL KEEP LOWS MAINLY
IN THE 60S THROUGHOUT THE EXTENDED PERIODS.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1239 PM CDT SUN JUN 16 2013

THE RISK FOR HAIL AND GUSTY WINDS WITH THUNDERSTORM ACTIVITY THIS
AFTERNOON AND EVENING ARE THE PRIMARY AVIATION CONCERNS IN WESTERN
NEBRASKA FOR THE CURRENT TAF PERIOD. STORMS ARE EXPECTED TO
FURTHER DEVELOP ACROSS NORTHERN NEBRASKA AND POSSIBLY IN THE
PANHANDLE EARLY THIS AFTERNOON. THE STORMS WILL TRACK SOUTH AND
EAST AND HAVE THE POTENTIAL TO PRODUCE LARGE HAIL AND GUSTY
NORTHWEST WINDS BEFORE MOVING OUT OF THE AREA THIS EVENING. THE
OVERNIGHT LOOKS QUIET WITH PREVAILING VFR CONDITIONS.

&&

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

$$

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