000
FXUS63 KLBF 151149
AFDLBF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
649 AM CDT WED MAY 15 2013

.UPDATE...
ISSUED AT 648 AM CDT WED MAY 15 2013

A WEAK DISTURBANCE MAINLY AFFECTING SOUTH DAKOTA CURRENTLY WILL
AFFECT WESTERN NEBRASKA THIS MORNING ON THE SOUTHERN PERIPHERY.
VIRGA IS VISIBLE WITH POCKETS REACHING THE GROUND IN EASTERN
CHERRY COUNTY...BROWN AND LOUP COUNTY. STILL ENOUGH VERTICAL
DEVELOPMENT WITH A FEW ECHO TOPS IN EASTERN CHERRY COUNTY NEAR 35K
FEET SUPPORTIVE OF ISOLATED THUNDER. MENTION FOR SLIGHT CHANCE
SHOWERS ISOLATED THUNDER NORTH CENTRAL NEBRASKA THROUGH 15Z.
THEREAFTER...EXPECTING DRY CONDITIONS AND CLEARING SKIES FOR BALANCE
OF DAY WITH GOING HIGHS ON TRACK.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 348 AM CDT WED MAY 15 2013

ISOLATED SHOWERS AND A FEW THUNDERSTORMS CONTINUE TO DIMINISH
THROUGH THE EARLY MORNING HOURS FROM A WEAK DISTURBANCE MOVING
ACROSS SOUTH DAKOTA AND NORTHERN NEBRASKA. EXPECT MOST IF NOT ALL
OF THE SHOWERS TO EXIST EASTERN AREAS BY 12Z.

A DAY AFTER RECORD SETTING HIGH TEMPERATURES AT LBF...BBW...AND
IML...HIGHS TODAY WILL BE COOLER...YET ABOUT 7 TO 10 DEGREES ABOVE
NORMAL IN THE UPPER 70S TO LOWER 80S. WENT A FEW DEGREES ABOVE
GUIDANCE WITH HIGH THE LAST SEVERAL DAYS EXCEEDING GUIDANCE. SKIES
TODAY WILL BE PARTLY SUNNY FROM FAIRLY SUBSTANTIAL MID LEVEL
MOISTURE. SURFACE WINDS WILL BE EASTERLY AT 10 TO 15 MPH. THE MID
LEVEL WINDS WILL BE LIGHT WESTERLY AT 5 TO 10 KTS. THERE IS A SLIGHT
POSSIBILITY FOR ISOLATED SHOWER DEVELOPMENT TODAY FROM WEAK
DISTURBANCES IN THE FLOW. DUE TO ABSENCE OF SUFFICIENT LIFT IN THE
MID LEVELS...AND THE SURFACE FRONT LOCATED FROM NRN KS INTO FAR
SOUTHEAST NEBRASKA...WILL GO WITH A DRY FORECAST TODAY. A SHORT WAVE
TROUGH CURRENTLY LOCATED ACROSS NEVADA WILL LIFT NORTHEAST TODAY
REACHING EASTERN UTAH THIS EVENING. CONVECTION WILL DEVELOP ACROSS
THE HIGHER TERRAIN OF COLORADO AND WYOMING THIS AFTERNOON AND WILL
MOVE INTO THE NEBR PANHANDLE THIS EVENING...THEN EASTWARD ACROSS
WESTERN AND NORTH CENTRAL NEBRASKA OVERNIGHT. COVERAGE SHOULD BE
ISOLATED ACROSS SOUTHWESTERN AND EASTERN AREAS OVERNIGHT...BUT MAY
BECOME SCATTERED ACROSS WESTERN AND CENTRAL PORTIONS OF NORTH
CENTRAL NEBRASKA. THE GFS/GEM MODELS FAVOR THE PANHANDLE AND WESTERN
SANDHILLS OVERNIGHT...WHILE THE NAM FAVORS DEVELOPMENT FURTHER EAST
ACROSS THE FA. THIS LOOKS TO BE A TIMING ISSUE WITH THE NAM THE
SLIGHTLY FASTER MODEL. MOISTURE WILL BE ON THE INCREASE THROUGH
TONIGHT...AS PRECIPITABLE WATER VALUES RISE TO AROUND AN INCH.
DESPITE INCREASED MOISTURE AVAILABLE OVERNIGHT...ANY RAINFALL
AMOUNTS WILL BE LIGHT...LIKELY LESS THAN A QUARTER INCH.

.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 348 AM CDT WED MAY 15 2013

FORECAST CONCERNS THROUGH THIS PERIOD DEAL WITH PRECIPITATION
CHANCES THURSDAY THROUGH MONDAY AND COOLER /NEARER TO NORMAL
TEMPERATURES/.

THURSDAY...UPPER LOW OVER SOUTHERN NEVADA THIS MORNING WILL TRACK
EAST OVER THE NEXT 36 HOURS...AND WEAKEN. BUT...IT MAINTAINS DECENT
MID LEVEL ENERGY...WHICH MOVES ACROSS NEBRASKA THROUGH THE DAY. AT
THE SURFACE...A LEE-SIDE TROUGH DEVELOPS OUT WEST OF THE FORECAST
AREA. MODELS ARE IN GOOD AGREEMENT WITH THESE FEATURES...INCLUDING
DEVELOPING CONVECTION ALONG IT AS THERE LOOKS TO BE GOOD ENOUGH
CONVERGENCE...AS WELL AS INSTABILITY ACROSS THE ENTIRE FORECAST
AREA. SO FELT CONFIDENT TO INCREASE PRECIPITATION CHANCES
THURSDAY AND THURSDAY NIGHT. THERE IS AN OUTSIDE CHANCE FOR SOME
SEVERE STORMS IN THE AFTERNOON AND EVENING AS THERE WILL BE PLENTY
OF INSTABILITY TO WORK WITH...AND WIND PROFILES SHOW FAVORABLE
SHEAR IN THE 0-6KM LAYER IN THE AFTERNOON. ALTHOUGH NOT REAL
EXCITED ABOUT TEMPERATURES THURSDAY ARE A BIT TRICKY AS
TEMPERATURES ALOFT RISE THROUGH THE DAY DUE TO WARM AIR ADVECTION
WITH SOUTHERLY FLOW. BUT...WITH SHOWERS AND THUNDERSTORMS
EXPECTED...AND QUITE A BIT OF CLOUD COVER...WENT ON THE COOLER
SIDE OF HIGHS. SO LOOKING FOR UPPER 70S TO LOW 80S. ALSO...EXPECT
BREEZY SOUTHERLY WINDS...WHICH WILL BRING MORE MOISTURE INTO THE
AREA...WITH DEWPOINTS ANTICIPATED IN THE UPPER 40S TO AROUND 60
DEGREES.

IN TERMS OF THE UPPER LEVEL PATTERN THROUGH THE REST OF THE
PERIOD...THE FLOW AMPLIFIES AS THE RIDGE BUILDS BACK IN OVER THE
PLAINS FOR THE LATTER PART OF THE WEEK AND TROUGHING DIGS IN OVER
THE WESTERN CONUS. THIS PUTS THE FORECAST AREA IN AN AREA OF
SOUTHERLY FLOW WHICH WILL INCREASE MOISTURE THROUGH THE REMAINDER
OF THE WEEK.

DRY LINE FRIDAY AFTERNOON TO SPARK THUNDERSTORMS ACROSS THE AREA.
THE LOCATION OF THIS FEATURE IS FAIRLY CONSISTENT BETWEEN MODEL
SOLUTIONS...WHICH IS OVER THE EASTERN PANHANDLE IN THE AFTERNOON.
WITH SLIGHT HELP FROM UPSLOPE LOW LEVEL FLOW...THINK BEST AREA FOR
DEVELOPMENT WILL BE OVER THE PANHANDLE INTO THE WESTERN SANDHILLS
/AND POTENTIALLY IN FAR SOUTHWEST NEBRASKA/. WHERE THIS
DEVELOPS...WILL DETERMINE WHAT AREAS SEE STORMS. WILL KEEP HIGHER
POPS OVER NORTHERN NEBRASKA DUE TO STEERING FLOW SHOWING ACTIVITY
WILL MOVE NORTH/NORTHEAST. DEEP LAYER SHEAR WEAKENS FROM THURSDAY
AFTERNOON AS THE RIDGE HAS BUILT BACK INTO THE PLAINS...SO SEVERE
CHANCES DON/T LOOK AS GOOD AS THEY MAY HAVE IN PAST FORECAST
ISSUANCES. WILL KEEP AN EYE ON IT IN THE COMING DAYS.

SATURDAY LOOKS VERY SIMILAR...WITH THE SURFACE TROUGH OVER
NEBRASKA BEING A FOCUS FOR STORMS TO DEVELOP. WIND SHEAR ISN/T
REAL STRONG...BUT COULD BE ENOUGH TO GET A FEW ORGANIZED STORMS.
THERE IS A QUESTION TO IF SOME AREAS WILL STAY CAPPED SATURDAY
AFTERNOON...BUT IF THE CAP CAN BREAK...OR IF ELEVATED ACTIVITY
DEVELOPS...THERE IS GOOD CAPE FOR THUNDERSTORMS.

THEN ON SUNDAY...A STRONGER SHORTWAVE ROTATES THROUGH THE UPPER
LEVEL TROUGH AND ACROSS THE CENTRAL PLAINS. THIS WILL BRING
FURTHER CHANCES FOR SHOWERS AND STORMS TO THE AREA THROUGH THE
DAY. THIS MAY BE THE HIGHEST CHANCES FOR WIDESPREAD RAINFALL. AT
THIS TIME...THE UPPER PATTERN HAS SHIFTED EAST...WITH THE RIDGE
NOW CENTERED OVER THE GREAT LAKES ON SUNDAY. MONDAY COULD BE WET
AS WELL AS THE SHORTWAVE TROUGH MOVES UP INTO NORTHERN
MINNESOTA...AND FURTHER ENERGY EJECTS OUT OF THE TROUGH TO KEEP A
MENTION OF PRECIPITATION THROUGH MONDAY. ADDITIONALLY...ALTHOUGH
TEMPERATURES THROUGH SUNDAY WILL STAY IN THE 70S/80S...IF THE
UPPER LOW ON MONDAY DOES IN FACT DEEPEN OVER MINNESOTA...IT WOULD
PULL COOLER AIR SOUTH AND INTO THE FORECAST AREA. THIS COULD MEAN
HIGHS BACK DOWN INTO THE 60S AND LOW 70S FOR MONDAY AND TUESDAY.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 623 AM CDT WED MAY 15 2013

LOOK FOR BROKEN MID AND HIGH CLOUDINESS TO BECOME SCATTERED THIS
AFTERNOON. EASTERLY WINDS TO BE GENERALLY 10KT OR LESS...EXCEPT
AT KLBF WHERE GUSTS UP TO 18KT AT TIMES INTO THIS AFTERNOON. VFR
CONDITIONS FORECAST. SLIGHT CHANCES FOR SHOWERS AND THUNDERSTORMS
AFTER 03Z. DUE TO ISOLATED COVERAGE...NO MENTION IN TAFS YET.


&&

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

$$

UPDATE...ROBERG
SHORT TERM...ROBERG
LONG TERM...BROOKS
AVIATION...ROBERG