392 FXUS63 KOAX 190550 AFDOAX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE OMAHA/VALLEY NE 1150 PM CST FRI JAN 18 2013 .AVIATION... 00Z TAFS FOR KOMA..KLNK AND KOFK. MAINLY MID AND HIGH CLOUDS FOR MUCH OF THE PERIOD. MVFR CLOUDS MAY MOVE INTO KOFK AFTER 03Z SATURDAY NIGHT. VARIABLE WINDS WILL BECOME NORTHWEST 10 TO 15KTS AFTER 12Z AND INCREASE TO 15 TO 22KTS WITH HIGHER GUSTS LATER SATURDAY AT ALL SITES. ZAPOTOCNY && .PREV DISCUSSION... /ISSUED 949 PM CST FRI JAN 18 2013/ UPDATE... MINOR UPDATES THIS EVENING TO TWEAK TEMPERATURES AND INCREASE CLOUDS. DISCUSSION... AFTER A DAY OF MUCH ABOVE NORMAL TEMPERATURES WITH HIGHS IN THE 40S...50S...AND 60S (NORFOLK...ALBION..AND FALLS CITY)...READINGS BY 03Z HAD SETTLED BACK INTO THE THE 30S. FM THE 00Z UPPER AIR CHARTS...A STRONG H3 100+KT JET WAS HEADING TOWARD MT. A COMPLEX MID TROPOSPHERIC TROF OF CANADA WILL SEND SOME LEAD ENERGY ACROSS MT AND THE DAKOTAS TONIGHT WITH MID CLOUDS MOVING THROUGH TONIGHT AND EARLY SATURDAY MORNING. THE STRONGER PORTION OF THE WAVE WILL MOVE THROUGH SATURDAY...DRAGGING A COLD FRONT THROUGH. ONE MORE MILD DAY AHEAD OF COLDER...THEN MUCH COLDER CONDITIONS FOR SUNDAY AND MONDAY. THE NAM HAS SOME STRONG H85 55KTS WINDS WITH THE FRONT SATURDAY AFTERNOON. WILL PASS ON TO THE NEXT SHIFT THAT HEADLINES FOR A WIND ADVISORY MAY NEED TO BE CONSIDERED IN THE NORTH. PREV DISCUSSION... /ISSUED 314 PM CST FRI JAN 18 2013/ SHORT TERM...TONIGHT THROUGH MONDAY ONE MORE DAY OF WARMTH IS IN STORE BEFORE TEMPERATURES FALL FROM ABOVE TO BELOW NORMAL. SUBJECTIVE 12Z UPPER AIR ANALYSIS INDICATES UPPER-LEVEL TROUGHING TO THE EAST...WITH ANOTHER TROUGH IN THE SOUTHWEST US. 500MB HEIGHTS WERE FALLING FROM SOUTHWEST CANADA TO THE HIGH PLAINS AHEAD OF A CANADIAN SHORTWAVE...BUT UPPER-LEVEL JET WAS STRONGEST WELL EAST...FROM THE GREAT LAKES TO NEW ENGLAND. 850MB TROUGH WAS MOVING ACROSS THE CENTRAL PLAINS...WITH WARMER AIRMASS BEHIND IT...WHILE COLDEST 850MB TEMPS WERE CONFINED TO THE EASTERN HALF OF CANADA AND THE NORTHEAST US. SURFACE LOW AT 20Z WAS CENTERED IN CENTRAL MN...WITH A SECONDARY LOW IN SOUTHWEST CO...AND BROAD TROUGHING BETWEEN FROM SOUTHWEST MN THROUGH NORTHEAST NEB AND CENTRAL NEB TO NORTHWEST KS. MAIN FORECAST CONCERN IS COLD AIR INTRUSION LATER THIS WEEKEND. IN THE MEANTIME...WINDS SHOULD REMAIN HIGH ENOUGH TO KEEP LOW-LEVEL MOISTURE FROM SETTLING INTO FOG /AND HOPEFULLY ALSO FROM SETTLING ONTO BRIDGES AND ROADS/ TONIGHT. HAVE BUMPED UP TEMPS FOR SATURDAY IN MOST PLACES...ESPECIALLY IN THE SOUTH...WITH MOST OF THE DAY AVAILABLE FOR WARMING BEFORE COLD AIR ARRIVES. WINDS WILL SWITCH TO A WEST-NORTHWEST COMPONENT BY MID-AFTERNOON...AND HIGHS MAY OCCUR CLOSER TO MIDDAY IN THE NORTH AND CENTRAL CWA. DO HAVE SOME GUSTY WINDS IN THE GRIDS RIGHT NOW IN THE NORTHERN CWA BEHIND THE FRONT IN THE AFTERNOON/EARLY EVENING...BUT SO FAR AM BORDERLINE OR JUST SHY OF ADVISORY CRITERIA...AND WILL HOLD OFF ON HEADLINES. TEMPS WILL FEEL MUCH COLDER ON SATURDAY NIGHT...BUT WINDS AND INCREASING CLOUDS SHOULD PREVENT A FULL DROPOFF. SECOND PUSH OF COLDER AIR IS PROGGED TO ARRIVE ON SUNDAY AFTERNOON IN ASSOCIATION WITH A SHORTWAVE...AND THIS TIME COMES WITH A BIT MORE MID-LEVEL MOISTURE IN THE ENTRANCE REGION OF A STRENGTHENING UPPER-LEVEL JET. HAVE KEPT MENTION OF FLURRIES IN THE NORTHERN CWA ON SUNDAY AFTERNOON...AS BETTER CHANCE FOR MEASURABLE SNOW LOOKS TO LINGER JUST NORTHEAST OF THE CWA. THAT SAID...A FEW SREF MEMBERS AND THE 18Z NAM DO INDICATE MEASURABLE SNOW IN THE NORTHEAST CWA...AND THIS WILL NEED ANOTHER LOOK IN LATER SHIFTS. HAVE KEPT TEMPS COOL IN THE NORTH/NORTHEAST CWA WHERE CLOUDS WILL BE MOST PERSISTENT...BUT ALSO NUDGED UP JUST A DEGREE OR TWO IN THE SOUTHWEST...FURTHEST FROM THE CLOUDS AND COLDEST AIR. MADE LITTLE CHANGE TO TEMPS FOR SUNDAY NIGHT AND MONDAY...WITH LOWS IN THE SINGLE DIGITS BELOW TO SINGLE DIGITS ABOVE...AND HIGHS IN THE LOW TEENS TO MID 20. BOTH OF THESE SHOULD BE THE COLDEST READINGS OF THE WEEK. MAYES LONG TERM...MONDAY NIGHT THROUGH FRIDAY DRY THROUGH THE PERIOD WITH TEMPERATURE THE MAIN FORECAST ISSUE. TUESDAY LOOKS TO BE THE TAIL END OF THE ARCTIC AIR AS COLD HIGH PRESSURE SHIFTS EAST OF THE REGION. THERE WILL LIKELY BE SOME LINGERING CLOUDINESS...ALONG WITH A LIGHT EASTERLY FLOW RESULTING IN POOR MIXING. HPC GUIDANCE FORECAST GUIDANCE HAS BEEN VERIFYING BETTER IN RECENT WEEKS FOR HIGHS...THUS ADJUSTED TEMPS DOWN FROM PREVIOUS FORECAST A FEW DEGREES TUESDAY. A SIGNIFICANT WARMUP OCCURS WEDNESDAY AS SOUTHERLY FLOW RETURNS ALONG WITH A LOT OF SUNSHINE. THIS SHOULD BOOST TEMPS INTO THE UPPER 30S TO LOWER 40S...AGAIN MORE IN LINE WITH HPC GUIDANCE VERSUS MODEL ALLBLEND. A SURFACE TROUGH MOVES THROUGH ON THURSDAY. THIS WILL BRING VERY STRONG MIXING AND A WIND SHIFT TO THE NORTHWEST. WITH DOWNSLOPING FLOW AND ABUNDANT SUNSHINE...WE SHOULD MAINTAIN TEMPS IN THE UPPER 30S TO MID 40S...ALONG WITH QUITE BREEZY CONDITIONS. ALONG WITH THE WIND SHIFT...COLDER AIR FILTERS BACK INTO THE AREA FOR FRIDAY WITH TEMPS BACK INTO THE UPPER 20S TO MID 30S. AGAIN...MOISTURE THROUGH THE EXTENDED REMAINS NIL...THUS NO ACTUAL WEATHER EXPECTED DURING THIS TIME. DEWALD && .OAX WATCHES/WARNINGS/ADVISORIES... NE...NONE. IA...NONE. && $$ ZAPOTOCNY