HAMweather.com Area Forecast Discussion for County Warning Area LBF

Thu, 16 Feb 2012 12:12:38 GMT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
552 AM CST THU FEB 16 2012

.AVIATION...

FOR THE KLBF AND KVTN TERMINALS THROUGH 12Z FRIDAY.

WITH THE EXCEPTION OF SOME MID LEVEL CLOUDINESS ACROSS SOUTHERN 
NEBRASKA...MOSTLY CLEAR SKIES ARE LIKELY THROUGH 12Z FRIDAY. MID 
LEVEL CLOUDINESS WITH CIGS RANGING FROM 8000 TO 10000 FT AGL WILL 
IMPACT THE SOUTHEASTERN PANHANDLE AND PORTIONS OF SOUTHWESTERN 
NEBRASKA THROUGH 16Z THIS MORNING AND WILL IMPACT THE KLBF TERMINAL 
THROUGH THIS TIME. FOR THE KVTN TERMINAL...EXPECT MOSTLY CLEAR SKIES FOR THE 
PERIOD. WINDS WILL BE LIGHT AND VARIABLE THIS MORNING...WITH A SHIFT 
TO THE WEST AT AROUND 10 KTS FOR THIS AFTERNOON AND INTO THE EVENING 
HOURS. AT THE KVTN TERMINAL...WINDS WILL SHIFT TO THE NORTH AT 
AROUND 10 KTS AFTER 06Z FRIDAY...AS A WEAK COLD FRONT PUSHES INTO 
NORTHERN NEBRASKA. 

.PREV DISCUSSION... /ISSUED 347 AM CST THU FEB 16 2012/

DISCUSSION...

.SHORT TERM...GENERALLY QUIET CONDITIONS CAN BE EXPECTED FOR THE 
NEXT 48 HOURS AS NORTHWESTERLY FLOW HAS BECOME ESTABLISHED ACROSS  
THE NORTHERN HIGH PLAINS.  HOWEVER WITH GOOD AGREEMENT...SHORT TERM 
MODEL SOLUTIONS INDICATE A CLIPPER TYPE SYSTEM WHICH WILL QUICKLY 
DIVE SOUTH OUR OF CANADA ON FRIDAY.  AS THE SHORTWAVE TROUGH DIVES 
SOUTH...AN ATTENDANT COLD FRONT WILL USHER IN SLIGHTLY COOLER 
TEMPERATURES BY AFTERNOON.  STILL LOOKING AT NEAR CLIMATOLOGICAL 
VALUES THOUGH...AS HIGHS SHOULD REMAIN IN THE UPPER 30S TO LOW 40S 
REGION WIDE.  WHILE TEMPERATURE IMPACTS WILL BE MINIMAL WITH THIS QUICK 
HITTING SYSTEM...A SLIGHT CHANCE OF SHOWERY TYPE PRECIPITATION WILL 
BE POSSIBLE FRIDAY EVENING AS FORCING INCREASES WITH THE PASSING 
WAVE.  BUFR SOUNDINGS REVEAL TWO COMPLICATIONS...FIRST THE LOWER 
LEVELS REMAIN FAIRLY DRY...SO NOT ENTIRELY CONVINCED THAT IF 
PRECIPITATION WERE TO DEVELOP IT WOULD ACTUALLY MAKE IT TO THE 
GROUND. BUT ALSO BUFR SOUNDINGS DO SUGGEST SOME INSTABILITY /ALBEIT 
WEAK/ WILL BE PRESENT THROUGH THE COLUMN.  SIMILAR CASES HAVE 
OCCURRED OVER THE PAST MONTH OR SO WHERE WEAK INSTABILITY HAS 
DEVELOPED SLIGHTLY CONVECTIVE SHOWERS WHICH WERE ABLE TO OVERCOME 
THE DRIER LOW LEVELS.  FOR NOW WILL CONFINE  THE SHOWER MENTION 
ALONG THE SOUTH DAKOTA BORDER...BUT BUFR SOUNDINGS WOULD INDICATE 
THE POTENTIAL POSSIBLY AS FAR SOUTH AS THE CENTRAL SAND HILLS.  WILL 
SEE HOW FOLLOWING GUIDANCE PLAYS OUT TODAY AND MAKE ADJUSTMENTS 
ACCORDINGLY.

.LONG RANGE...THERE ARE SIGNIFICANT DIFFERENCES BETWEEN MODEL 
SOLUTIONS AS EARLY AS SATURDAY MORNING...THUS CONFIDENCE IS NOT AS 
HIGHS AS IT SHOULD BE.  THE 16.00Z EURO RETAINS UPPER LEVEL ENERGY 
AND SURFACE HIGH PRESSURE MUCH FURTHER WEST /OVER NEBRASKA/ THAN 
THAT THE GFS INDICATES.  THE EURO SOLUTION WOULD ALLOW FOR SLIGHTLY 
COOLER TEMPERATURES AND THE POSSIBILITY OF LIGHT QPF ON SATURDAY 
ACROSS WESTERN NEBRASKA.  THIS SOLUTION SEEMS TO BE OUTLIER...SO 
GENERALLY FOLLOWED THE GFS /AND SOME EXTEND THE GEM/ WHICH SUGGESTS 
THAT UPPER LEVEL ENERGY/SURFACE HIGH PRESSURE WILL PUSH EAST 
ON SATURDAY...WITH WESTERLY TO EVENTUALLY SOUTHERLY FLOW RETURNING 
TO WESTERN NEBRASKA.  THIS WOULD ALLOW TEMPERATURES TO WARM SLIGHTLY 
FOR THE WEEKEND...SUCH THAT BY SUNDAY...MID TO UPPER 40S MAY BE THE 
NORM.  SHORTWAVE RIDGING ALOFT SHOULD SHIFT EAST ACROSS THE CWA 
SATURDAY AND SUNDAY...WHICH IN TURN WILL FORCE THE ACTIVE NORTHERN 
STORM TRACK EAST.  THE WEEKEND APPEARS TO BE DRY ACROSS WESTERN AND 
NORTH CENTRAL NEBRASKA IF THIS FAVORED SOLUTION VERIFIES.

CHANGES ARE IN STORE FOR EARLY NEXT WEEK...BUT UNFORTUNATELY AFTER 
SEVERAL CONSISTENT RUNS...THE LONG RANGE MODELS HAVE BEGUN TO 
DIVERGE AND SHOW SIGNS ONCE AGAIN OF INCONSISTENCY.  THE TREND OF 
THE EARLY WEEK STORM HAS BEEN SLOWER...AND WITH THE PAST TWO MODEL 
CYCLES...THE CONSENSUS SEEMS NOW TO SUGGEST A BROAD OPEN TROUGH WITH 
VARYING DEGREES OF TIMING AND LOCATION.  CONFIDENCE IS MUCH LOWER 
TONIGHT THAN LAST NIGHT...SO GIVEN THE BLENDED GUIDANCE OF 30 TO 40 
POP SEEMS REASONABLE FOR MONDAY.  FOR SUNDAY NIGHT AND EARLY 
MONDAY...WILL RETAIN SLIGHT CHANCE POPS AS WELL...BUT WITH THE 
CONTINUED INDICATED SLOWING OF THE SYSTEM...POPS MAY NEED TO BE 
LOWERED FURTHER.

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