000
FXUS63 KLBF 131729
AFDLBF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
1229 PM CDT THU JUN 13 2013

.SYNOPSIS...
ISSUED AT 335 AM CDT THU JUN 13 2013

PROGRESSIVE UPPER PATTERN CONTINUES ACROSS THE
COUNTRY...INCLUDING SEASONALLY HIGH AMPLITUDE RIDGE MOVING ACROSS
THE NORTHERN ROCKIES. FURTHER UPSTREAM...UPPER LOW MOVING ONSHORE
ACROSS THE PAC NW LEADING TO DECENT JET AXIS ACROSS THE CENTRAL
ROCKIES BASED ON EVENING UA ANALYSIS. AT THE SFC...HIGH PRESSURE
ACROSS THE NORTHERN PLAINS YIELDING ERLY UPSLOPE FLOW ACROSS THE
STATE. STATIONARY FRONT LOCATED ACROSS SRN KS AND NORTH OF THIS
FRONT SPC MESOANALYSIS HAS INDICATED DECREASING MID LEVEL LAPSE
RATES AS WARM AIR ADVECTION INCREASES ALOFT. COOLING CLOUD TOPS
INDICATED IN IR SAT PICS IN NERN CO AND NRN KS IN RESPONSE TO
INCREASING MID LEVEL FRONTOGENESIS.

&&

.UPDATE...
ISSUED AT 647 AM CDT THU JUN 13 2013

UPDATED FORECAST TO REFLECT THE MENTION OF THUNDER TO THE EXISTING
PRECIPITATION GRIDS...THE PLACEMENT OF WHICH WAS ON TRACK. REST OF
THE FCST LOOKS INGOOD SHAPE.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 335 AM CDT THU JUN 13 2013

IN THE VERY SHORT TERM...THROUGH NOON TODAY...ISOLD SHRA WILL BE
POSSIBLE IN THE WEST INITIALLY TO COVER ECHOES ON RADAR GENERATED
BY A WESTWARD MOVING BOUNDARY SEEN EARLIER ON THE KFTG 88D. AS
MENTIONED EARLIER...ELEVATED INSTABILITY IS PRESENT AND RAP SHORT
TERM FCSTS SHOW MID LEVEL FRONTOGENESIS AS THE THERMAL GRADIENT
TIGHTENS AS A RESULT OF THE WAA AS MENTIONED. THEREFORE WILL
INCLUDE ISOLD SHRA MENTION IN SOUTHWEST THIS MORNING...THOUGH THIS
WILL BE A LOW QPF /IF ANY AT ALL/ EVENT. MAY BE A LIGHTNING STRIKE
OR TWO BUT LATEST INFO SUGGESTS SOME WEAKENING CURRENTLY.

IN RESPONSE TO THE JET COMING ACROSS THE CENTRAL ROCKIES SFC
PRESSURES WILL LOWER OVER THE NORTHERN HIGH PLAINS THRU THE DAY
TODAY. WINDS WILL BECOME SOUTHEAST AND WILL RESULT IN AN INCREASE
IN LOW LEVEL MOISTURE IN THE NEXT 24 HRS. SEVERAL SMALL PV
ANOMALIES ARE EMBEDDED WITHIN THE QUICK FLOW AND WILL SERVE TO
ENHANCE LOW LEVEL CONVERGENCE AS A THERMAL GRADIENT DEVELOPS ALONG
THE HIGHER TERRAIN. THIS SHOULD YIELD A FAVORABLE PATTERN OF
INSTABILITY ALOFT AS AN EML ADVECTS EASTWARD ATOP LOW LEVEL
MOISTURE ADVECTION. HOWEVER...SFC BASED INSTABILITY WILL REMAIN
LACKING IN THIS PATTERN WHICH WOULD MEAN THE BEST FORCING FOR
ASCENT AND SUBSEQUENT TSRA DEVELOPMENT WOULD BE MOST FAVORABLE
ACROSS THE HIGHER TERRAIN FURTHER WEST...AND THEN MOVE EAST
SUPPORTED BY THE FAVORABLE ELEVATED INSTABILITY. MODELS HAVE THIS
IDEA HANDLED FAIRLY WELL...HOWEVER AS EXPECTED FINE SCALE DETAIL
REMAIN A CHALLENGE. INCREASING MID AND HIGH LEVEL CLOUDINESS AND
EVEN SMOKE FROM FIRES IN COLORADO COULD MAKE TEMP FCSTS A TRICK
TODAY BUT WILL BE COOLER IN THE SOUTHWEST THAN YDAY WARMER IN THE
NORTH.

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 335 AM CDT THU JUN 13 2013

FRIDAY MORNING WILL SEE A LINGERING CHANCE FOR THUNDERSTORMS
ACROSS PARTS OF NORTH CENTRAL NEB AS OVERNIGHT CONVECTION
CONTINUES TO PROPAGATE EASTWARD. STALLED SFC BOUNDARY STRETCHES
FROM LOW OVER NW KS NORTHWARD TO A LOW OVER THE PLAINS OF CANADA.
UPPER LEVEL RIDGE REMAINS OVER THE SOUTHERN PLAINS. LOW
CONFIDENCE ON HIGHS...AS SEVERAL THINGS TO CONSIDER. WARM TEMPS
ALOFT SHOULD PRECLUDE ANY THUNDERSTORM DEVELOPMENT UNTIL LATE IN
THE AFTERNOON...MORE SUN AND WARM...HOWEVER DEPENDING ON
PLACEMENT OF THE SFC BOUNDARY...EXPECT SLIGHTLY COOLER TEMPS TO
THE WEST. HAVE SIDED TOWARDS THE WARMER GUIDANCE TO THE
SOUTH...SEEING MORE INFLUENCE FOR THE WARMER TEMPS ALOFT FROM THE
RIDGE AND RECENT WARMER PERFORMANCE. MORE OF A MODEL BLEND ACROSS
THE NORTH. AS FOR THE AFTERNOON THUNDERSTORMS...GOOD INSTABILITY
WILL HAVE TO OVERCOME STRONG CAP. ISOLD DEVELOPMENT IS EXPECTED
NEAR THE BOUNDARY...THEN SHOULD PUSH NE DUE TO THE SOUTHWEST FLOW
THROUGH THE OVERNIGHT HOURS. CAP MAY KEEP CELLS MORE
DISCRETE...ALTHOUGH EXPECTING MORE OF A COMPLEX AT THIS TIME.

SATURDAY THE FRONT WILL SHIFT SOUTH WITH THE MAIN CONVECTION TO
PUSH SOUTH WITH IT. HOWEVER ELEVATED MOISTURE WILL WRAP AROUND
THE RIDGE...ALONG THE ROCKIES INTO THE HIGH PLAINS. ALSO SEEING A
COUPLE OF WAVES RIDE THE PERIPHERY OF THE RIDGE. THUS WILL
CONTINUE TO SEE THE CHANCE FOR AFTERNOON AND OVERNIGHT ELEVATED
CONVECTION. TEMPS A LITTLE COOLER WITH HIGHS GENERALLY IN THE
80S. OVERNIGHT TEMPS MORE QUESTIONABLE AS CLOUDS WILL KEEP TEMPS
UP IN THE LOWER 60S...HOWEVER ANY CLEARING WILL ALLOW TEMPS TO
FALL INTO THE 50S.

EARLY NEXT WEEK THE RIDGE RETROGRADES AND BUILDS ACROSS THE
SOUTHERN ROCKIES. FLOW BECOMES MORE NORTHWESTERLY WITH A
CONTINUED CHANCE FOR CONVECTION...MAINLY AFTERNOON/EVENING IN THE
WEST...PUSHING TO THE EAST...EVENING/OVERNIGHT. TEMPS STILL IN
THE 80S MONDAY AND TUESDAY...THEN WARMING AS THE RIDGE EXPANDS
EASTWARD FOR MID WEEK. HIGHS SHOULD WARM TO THE MID 80S TO MID
90S...POSSIBLY WARMER.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1226 PM CDT THU JUN 13 2013

AVIATION CONCERNS OVER THE NEXT 24 HOURS CENTER AROUND THE CHANCES
FOR THUNDERSTORMS THIS EVENING INTO THE OVERNIGHT HOURS. HAVE
INCLUDED -TSRA IN THE KLBF TAF TONIGHT WITH MOST HI-RES MODELS
SHOWING SCATTERED CONVECTION MOVING OUT OF COLORADO AND INTO
SOUTHWEST NEBRASKA. STORMS WILL BE CAPABLE OF PRODUCING GUSTY
WINDS AND BRIEF HEAVY RAINFALL. HAVE LEFT ANY MENTION OF TS OUT OF
THE KVTN TAF WHERE CONFIDENCE IS MUCH LOWER ATTM.

&&

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

$$

UPDATE...JWS
SYNOPSIS...JWS
SHORT TERM...JWS
LONG TERM...MASEK
AVIATION...MARTIN