595 FXUS63 KLBF 292325 AAA AFDLBF AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE NORTH PLATTE NE 625 PM CDT SAT AUG 29 2015 .SYNOPSIS... ISSUED AT 348 PM CDT SAT AUG 29 2015 A STRONG TROUGH OF LOW PRESSURE ALOFT WAS PRESENT FROM THE ALASKAN PANHANDLE...SWD TO OFF THE COAST OF NRN CA THIS MORNING. DECENT HT FALLS OF 50 TO 100 METERS WERE NOTED FROM NRN CA INTO SWRN BRITISH COLUMBIA. JUST EAST OF THE TROUGH AXIS...A NICE 70 TO 90 KT H5 JET EXTENDED FROM NRN CA INTO SRN BRITISH COLUMBIA. DOWNSTREAM OF THIS TROUGH...HIGH PRESSURE WAS LOCATED OVER THE FOUR CORNERS WITH A RIDGE EXTENDING INTO EASTERN PORTIONS OF THE NW TERRITORIES OF CANADA. ACROSS THE EASTERN CONUS...A SHORTWAVE TROUGH EXTENDED FROM LAKE SUPERIOR INTO NRN ILLINOIS...WHILE A CLOSED LOW WAS NOTED JUST SOUTH OF THE FL PANHANDLE. AT THE SURFACE...WEAK HIGH PRESSURE WAS PRESENT ACROSS NEBRASKA...WHILE A SURFACE TROUGH OF LOW PRESSURE WAS PRESENT FROM EASTERN MONTANA SOUTH TO EASTERN COLORADO. WINDS WERE GENERALLY LIGHT THIS AFTERNOON AND SKIES WERE MOSTLY CLEAR...HOWEVER...A VEIL OF HAZE AND SMOKE ALOFT WAS PRESENT ACROSS THE FORECAST AREA. TEMPERATURES AS OF THE 3 PM CDT HOUR...RANGED FROM 85 AT ONEILL TO 92 AT OGALLALA AND IMPERIAL. && .SHORT TERM...(THIS EVENING THROUGH SUNDAY) ISSUED AT 348 PM CDT SAT AUG 29 2015 CONCERN IS MAINLY TEMPS AND FOG. SMOKE FROM WESTERN FIRES CAUSING HAZY SKIES...HOWEVER THIS SEEMS TO ONLY HAVE MINOR IMPACT ON TEMPS. THUS OVERNIGHT HAVE BLENDED GUIDANCE TO SIDED ON THE WARM SIDE WHICH DROPS TEMPS INTO THE LOWER 60S TO MID 50S. THERE IS A NOCTURNAL LL JET THAT DEVELOPS OVER THE WESTERN ZONES AND NOSES INTO S CENTRAL S DAKOTA. EXPECT THE JET TO KEEP LOWS THERE THE MILDEST. AS FOR THE FOG...LIMITED MIXING TODAY IN THE VALLEY AND OVER PORTIONS OF N CENTRAL...WHERE FOG BRIEFLY DEVELOPED THIS MORNING. HAVE DECIDED TO GO CLOSE TO PERSISTENCE...EVEN THOUGH THE SHREF PLUMS SUGGEST DEVELOPMENT SHOULD BE FURTHER EAST. PART OF THE REASONING WAS THE SHREF PLUMS YESTERDAY WERE NOT FAR ENOUGH WEST FOR WHAT RESULTED THIS MORNING. THIS WILL NEED TO BE WATCHED CLOSELY. TOMORROW THE RIDGE WILL CONTINUE TO DOMINATE THE AREA...WITH THE THERMAL RIDGE TO BE ACROSS NW NEB. THIS AREA SHOULD BE THE WARMEST...HIGHS IN THE MID TO UPPER 90S...WITH LOWER 90S ELSEWHERE. SOME MOS GUIDANCE TAKES THE NW TO TRIPLE DIGITS...HOWEVER THE HAZE WILL LIKELY REMAIN AND PREVENT THEM FROM TORCHING OUT. ANOTHER CONCERN WILL BE THE FIRE DANGER ACROSS THE WEST. DRY LINE PUSHES DEW PTS INTO THE 40S AND WILL COMBINE WITH THE MID TO UPPER 90S TO PRODUCE MIN RH VALUES FROM 15 TO 20 PERCENT. WINDS ALSO GUSTING TO AROUND 20 MPH. WHILE NOT CRITICAL CONDITIONS...A HIGH FIRE DANGER CAN BE EXPECTED. .LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY) ISSUED AT 348 PM CDT SAT AUG 29 2015 IN THE MID RANGE...A FROPA...AND LIMITED PCPN CHANCES WILL BE THE MAIN FORECASTING CONCERNS. ON SUNDAY NIGHT...AN UPPER LEVEL TROUGH OF LOW PRESSURE WILL LIFT FROM THE IDAHO PANHANDLE...INTO FAR NWRN ND BY 12Z MONDAY. THIS FEATURE WILL FORCE A COLD FRONT INTO THE FAR NORTHWESTERN CWA BY DAYBREAK MONDAY MORNING. LIFT IN THE VICINITY OF THE FRONT IS FARILY IMPRESSIVE ATTM...HOWEVER BOTH THE NAM AND GFS SOLNS ARE INDICATIVE OF VERY MEAGER LOW LEVEL MOISTURE IN THE NORTHWESTERN CWA...SO ANY CONVECTION WHICH MAY DEVELOPS...WILL BE PRETTY ELEVATED. WITH THIS IN MIND...WILL LIMIT POPS TO SLIGHT CHANCES ATTM. ALSO...WITH THE FRONTAL TIMING SLIGHTLY SLOWER NOW...HAVE CONFINED POPS TO THE FAR NORTHWESTERN CWA AND TAKEN THEM OUT OF THE SOUTHEASTERN PANHANDLE AND PORTIONS OF NORTH CENTRAL NEBRASKA. THE UPPER LEVEL TROUGH WILL LIFT INTO NORTHWESTERN ONTARIO ON MONDAY. THIS WILL FORCE THE COLD FRONT THROUGH MOST OF THE FORECAST AREA...STALLING THIS ACROSS SWRN TO NERN NEBRASKA BY MONDAY EVENING. AS THE FRONT PROGRESSES ON MONDAY...FELT MOISTURE...AND MID LEVEL INSTABILITY WAS LACKING CONSIDERABLY INVOF THE FRONT MONDAY...AND DECIDED TO LEAVE THE FORECAST DRY FOR NOW. HIGHS MONDAY WILL RUN 5 TO 10 DEGREES COOLER THAN SUNDAYS...AS THE FRONT WILL BE THROUGH MOST OF THE FA BY PEAK HEATING. HIGHS WILL RANGE FROM THE MID 80S IN NRN NEBRASKA...TO THE LOWER 90S IN THE FAR SOUTHWEST. AS MENTIONED EARLIER...THE FRONT WILL STALL ACROSS SWRN...CENTRAL AND NERN NEBRASKA MONDAY EVENING. AT THE SAME TIME...A DECENT MID LEVEL SHORTWAVE WILL TRACK FROM EASTERN COLORADO INTO SRN NEBRASKA AND NRN KS...INITIATING THUNDERSTORMS DURING THE EVENING HOURS. SB CAPES ALONG AND SOUTH OF THE COLD FRONT...WILL REACH 2000 TO 3000 J/KG ALONG A NARROW CORRIDOR IN THE EASTERN AND SERN PORTIONS OF THE CWA MONDAY EVENING WHICH WOULD SUPPORT A STRONG STORM OR TWO. HOWEVER...BULK SHEAR IS ONLY ON THE ORDER OF 20 TO 30 KTS MONDAY EVENING...SO SEVERE STORMS ARE NOT ANTICIPATED ATTM. INHERITED FCST HAD A STRIP OF 20 POPS ALONG THE FRONT AND THEY WILL BE CONTINUED. FOR TUESDAY...THE FRONT WILL BEGIN TO WASH OUT ACROSS CENTRAL NEBRASKA TUESDAY AFTERNOON AS WINDS TAKE ON A MORE SOUTHEASTERLY COMPONENT. THIS WILL FORCE LOW LEVEL MOISTURE WEST INTO CENTRAL PORTIONS OF THE FORECAST AREA TUES AFTN. THE COMBINATION OF THIS LOW LEVEL MOISTURE ALONG WITH FAVORABLE MID LEVEL LIFT...WILL BRING PCPN CHANCES BACK INTO THE FORECAST FOR SOUTHWESTERN...CENTRAL AND PORTIONS OF NORTH CENTRAL NEBRASKA LATE TUES. TUESDAY NIGHT THROUGH SATURDAY...THE MID RANGE MODEL SOLUTIONS INCLUDING THE 12Z GFS AND 12Z ECMWF SOLNS...TREND TOWARD BUILDING AN UPPER LEVEL RIDGE ACROSS THE CENTRAL AND EASTERN US...WITH A TROUGH NOTED ALONG THE WESTERN QUARTER OF THE CONUS. THROUGH THE END OF THE WEEK...THE HIGH PLAINS WILL REMAIN IN SWRLY FLOW ALOFT...USUALLY CONDUCIVE TO PRECIPITATION. HOWEVER...DEW POINTS ARE GENERALLY IN THE LOWER 50S NEXT WEEK...AND WITHOUT A DECENT LOW LEVEL BOUNDARY OR FOCUSING MECHANISM FOR PCPN...WENT WITH A DRY FCST. I DID HOWEVER BEGIN TO INCREASE PCPN CHANCES LATE NEXT WEEK AS THE UPPER LEVEL TROUGH BEGINS TO MIGRATE EAST. AS THE UPPER LEVEL TROUGH MOVES EAST...SRLY WINDS WILL INCREASE...LEADING TO INCREASED LOW LEVEL MOISTURE ACROSS THE CENTRAL PLAINS. MID LEVEL INSTABILITY WILL INCREASE AS WELL AS H5 TEMPS BEGIN TO COOL FRIDAY. && .AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING) ISSUED AT 625 PM CDT SAT AUG 29 2015 VFR IS EXPECTED OVERNIGHT AND SUNDAY. SPARSE AREAS OF SHALLOW FOG MAY FORM IN THE PLATTE VALLEY AND ACROSS PARTS OF NORTH CENTRAL NEBRASKA ALONG AND EAST OF HIGHWAY 281 LATE TONIGHT AND EARLY SUNDAY MORNING. OTHERWISE VFR IS EXPECTED ALL AREAS. && .LBF WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SYNOPSIS...CLB SHORT TERM...MASEK LONG TERM...CLB AVIATION...CDC