RSS FeedsIssued by NWS Grand Forks, ND
000 FXUS63 KFGF 210153 AFDFGF AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND FORKS ND 753 PM CST FRI NOV 20 2009 .DISCUSSION... THE MAIN CHALLENGE OVERNIGHT WILL BE TEMPS. THE PRESSURE GRADIENT WILL SLOWLY TIGHTEN OVERNIGHT...ALONG WITH INCREASING HIGH CLOUDS. WARM AIR ADVECTION ABOVE THE SFC WILL ALSO INCREASE. THIS SHOULD ALL SERVE TO HOLD TEMPS UP OVERNIGHT SO WILL INCREASE OVERNIGHT LOWS A BIT MAINLY ALONG AND WEST OF THE VALLEY WHERE WINDS WILL BE A BIT STRONGER THAN FURTHER EAST. ON SATURDAY...WINDS SHOULD INCREASE WITH A TIGHT PRESSURE GRADIENT AND NEARLY 45KT TO MIX FROM 925MB BY AFTERNOON. THE MAIN QUESTION WILL BE WHAT LEVEL MIX DOWN FROM. IF WINDS CAN MIX FROM 925MB...THEN A WIND ADVISORY MAY BE NEEDED FOR TOMORROW. IT WILL BE WINDY NONETHELESS...SO HAVE INCREASE WINDS IN THE GRIDS TO REFLECT THIS REASONING. && .AVIATION... SOUTHERLY WINDS WILL INCREASE BY SATURDAY AFTERNOON WITH GUSTS FROM 30-35KT POSSIBLE AT ALL SITES. VFR CONDITIONS WILL BE EXPECTED OTHERWISE WITH JUST SOME VERY HIGH CIRRUS AT TIMES THROUGH SATURDAY. && .PREV DISCUSSION... /ISSUED 259 PM CST FRI NOV 20 2009/ SHORT TERM... MAIN FCST CHALLENGE WILL BE TEMPS AND WINDS FOR SATURDAY. MODELS INITIALIZED WELL BUT GFS DIVERGES FROM REST OF ENSEMBLE SO WILL GO WITH A BLENDED NAM/ECMWF/GEMS SOLN ATTM. SFC ANALYSIS SHOWS RIDGE AXIS OVER CENTRAL PORTION OF MN SHIFTING E ALLOWING SRLY WINDS TO DEVELOP ACROSS THE AREA. ABUNDANT SUNSHINE WILL KEEP TEMPS PROPPED UP THIS AFTERNOON AND INCREASING THICKNESSES...ALONG WITH INCREASING CLOUD COVER...WILL LIMIT COOLING OVERNIGHT. PACIFIC FRONT WILL BEGIN PUSHING INTO THE DVL BASIN LATE SAT AFTERNOON AND EXIT THE AREA BY LATE SAT NIGHT. AHEAD OF THE FRONT...PRESSURE GRADIENT INCREASES AND 850MB WINDS OF 40 TO 50 KNOTS IS EXPECTED TO MIX DOWN TO THE SFC. THEREFORE...LOOKING TO SEE SFC GUSTS APPROACHING 30 MPH FROM THE VALLEY WEST...BUT NOT ANTICIPATING REACHING ADVISORY CRITERIA ATTM. COOLER AIR BEHIND THE FRONT WILL DROP TEMPS TO MORE SEASONAL VALUES. WITH LIMITED MOISTURE DUE TO DRIER AIR IN THE LOWER LEVELS...NOT ANTICIPATING MUCH IN THE WAY OF PCPN WITH THE FRONT. FOR MONDAY...DEVELOPING LOW PRESSURE SYSTEM IN THE CENTRAL PLAINS WILL PROVIDE THE NEXT CHANCE FOR PCPN AS INVERTED TROF CROSSES THE REGION. ANTICIPATE MOST OF THE MOISTURE WILL REMAIN SOUTH AS IT WRAPS INTO THE LOW...BUT SUFFICIENT MOISTURE SHOULD PUSH N AND LIFT ASSOCIATED WITH THE TROF WILL HELP PRODUCE -RA...MAINLY E OF THE VALLEY. LONG TERM (TUE-FRI)... THE LONG RANGE MODELS QUICKLY DIVERGE ON TIMING OF 500MB TROF/LOW AS IT MOVES THROUGH THE PLAINS AND INTO THE GREAT LAKES REGION FOR THE MIDDLE PART OF NEXT WEEK. THE GFS IS THE MEAN SOLUTION BETWEEN THE DGEX AND ECMWF AT THIS TIME. HOWEVER...THE ECMWF IS PREFERRED AT THIS TIME BECAUSE IT HAS BEEN THE MOST CONSISTENT. THUS...STILL KEPT CHC POPS FOR PCPN IN FORECAST FOR TUE AND TRENDED INTO E PARTS OF AREA FOR WED. AS FAR AS TEMPS...LOOK FOR TEMPERATURES TO REMAIN SLIGHTLY ABOVE NORMAL THROUGH THE EXTENDED FORECAST. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ DK
