Issued by NWS Bismarck, ND
000 FXUS63 KBIS 092214 AFDBIS AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BISMARCK ND 414 PM CST TUE FEB 9 2010 .SHORT TERM...TONIGHT THROUGH FRIDAY NIGHT... MAIN CONCERN TONIGHT WILL BE TEMPERATURES AND POSSIBLE PATCHY FREEZING FOG. COOL HIGH PRESSURE WILL CONTINUE TO DRIFT ACROSS THE REGION TONIGHT. GRADUAL RETURN FLOW AROUND THE HIGH WILL BRING SOUTHERLY WINDS TO THE WEST OVERNIGHT. MUCH OF THE AREA HAD PATCHY FOG AND STRATUS LAST NIGHT AND TEMPS WERE SLOW TO RECOVER TODAY. CURRENT THINKING IS ANOTHER PERIOD OF FREEZING FOG TONIGHT. INCREASING SOUTHERLY WINDS ACROSS THE HIGHER ELEVATION OF THE SOUTHWEST WILL PROBABLY INHIBIT FOG TONIGHT. ON WEDNESDAY WEAK BROAD WARM ADVECTION WILL OCCUR AHEAD OF A WEAK SHORTWAVE TROUGH ON THURSDAY. I KEPT A SLIGHT CHANCE OF SNOW IN FOR THURSDAY ASSOCIATED WITH THIS WEAK WAVE. A MORE SIGNIFICANT UPPER LOW ASSOCIATED WITH ANOTHER TROPOSPHERIC UNDULATION WILL MOVE INTO NORTH DAKOTA FRIDAY AND FRIDAY NIGHT. GEM/ECMWF/NAM MODELS MOVE THIS THE FARTHEST WEST...WITH GFS A BIT SLOWER AND FURTHER EAST. THIS FEATURE WILL BRING IN AN ARCTIC PUSH WITH COLDER AIR...AND SOME SNOW. .LONG TERM...SATURDAY THROUGH TUESDAY... HIGHLIGHT IN THE EXTENDED PERIOD WILL BE THE AFTER-EFFECTS OF THE UPPER LOW WHICH PASSES THROUGH THE NORTHERN PLAINS ON FRIDAY. WITH ARCTIC HIGH PRESSURE SETTLING IN OVER THE REGION IN THE UPPER LOWS WAKE...IT LOOKS TO BE COLD WITH SLIGHT CHANCES FOR LIGHT SNOW SHOWERS SAT DAYTIME. DECREASED FORECAST HIGHS BY ABOUT 10-15 DEGREES FOR SATURDAY AND ALSO LOWERED NIGHTTIME LOWS. I BELIEVE THESE TEMPS WILL NEED TO BE TRENDED DOWN A TAD MORE BEFORE ALL IS DONE. DEPENDING ON THE TIMING OF RETURN FLOW AND THE SOUTHERLY PROGRESSION OF THE SFC HIGH...TEMPS MAY NEED TO BE LOWERED AGAIN FOR SUNDAY. THE LATEST EC AND GFS DO DEPICT THE SFC HIGH LINGERING OVER THE LOCAL REGION THROUGH SUNDAY AFTERNOON...AND IF THIS VERIFIES WE WILL NEED TO LOWER DAYTIME HIGHS BY 10 DEGREES AS WELL AS LOWERING NIGHTTIME LOWS SAT AND SUN NIGHT. A WARMING TREND WILL EVENTUALLY TAKE PLACE FOR EARLY NEXT WEEK AS RETURN FLOW DEVELOPS OVER THE ENTIRE REGION AND AN UPPER LEVEL RIDGE NUDGES EAST TOWARDS THE PLAINS. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM...WAA LONG TERM /AVIATION...NH
