RSS FeedsIssued by NWS Sioux Falls, SD
000 FXUS63 KFSD 251413 AFDFSD AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA NATIONAL WEATHER SERVICE SIOUX FALLS SD 812 AM CST WED NOV 25 2009 .DISCUSSION.... QUICK UPDATE THIS MORNING TO DROP POPS AS WESTERN EDGE OF PRECIP SHIELD IS RAPIDLY ERODING AWAY. THOUGH UPPER LEVEL JET STREAK IS MOVING INTO WESTERN AND CENTRAL SOUTH DAKOTA...CURVATURE OF THE FLOW IS DOMINATING FEATURE SUPPORTING PRECIPITATION FURTHER TO THE SOUTH AND EAST THAN ONE MIGHT EXPECT. BREEZY DAY EXPECTED BORDERING ON WIND ADVISORY CRITERIA. PRESSURE COUPLET MAINLY FOCUSED ACROSS WESTERN SOUTH DAKOTA INTO WESTERN NEBRASKA...AND WHILE THINK WINDS WILL APPROACH WIND ADVISORY...THINK THEY WILL REMAIN BELOW ADVISORY CRITERIA FOR NOW. /BT && .PREV DISCUSSION... QUICK MOVING UPPER LEVEL LOW CURRENTLY CENTERED NEAR THE MN/ND/SD BORDER WILL DROP SE ACROSS THE CWA TODAY...BRINGING A SHOT OF SNOW MAINLY TO EASTERN AREAS. THIS IS A VERY DYNAMIC SYSTEM...BUT AS IT IS MOVING SO QUICKLY...SNOW AMOUNTS WILL BE LIMITED. COULD BE A MIX OF RAIN OR SNOW INTO NW IA THIS MORNING...BUT TEMPERATURES ALOFT COOL ENOUGH THAT ALL PRECIPITATION SHOULD SWITCH TO SNOW...EVEN IF SURFACE TEMPERATURES REMAIN ABOVE FREEZING. SNOW ACCUMULATIONS WILL MAINLY BE CONFINED OF AREAS EAST OF INTERSTATE 29...AND GENERALLY EXPECTING 1 INCH OF SNOW ALONG AND EAST OF THE BUFFALO RIDGE...BUT WOULD NOT RULE OUT ISOLATED 2 INCH AMOUNTS IN THIS AREA. IT HAS BEEN TOUGH TO GAUGE THE RATE OF SNOW FALL INTO NE SD AND ERN ND THIS MORNING DUE TO A LACK OF OBSERVATION SITES...HOWEVER...JMS REPORTED 5 HRS OF SN WITH VSBYS AROUND 3/4 MILE FOR A FEW HOURS. EXPECTING SIMILAR CONDITIONS ALONG AND EAST OF THE BUFFALO RIDGE. NOT EXPECTING ENOUGH SNOW ACCUMULATIONS FOR AN ADVISORY...BUT VSBYS COULD DROP BELOW 1/2 SM FOR A FEW HOURS IN PLACES...AND WHEN COMBINED WITH STRONG NW WINDS...COULD MAKE FOR TRICKY TRAVEL FOR A SHORT TIME TODAY. THE UPPER LEVEL DISTURBANCE RESPONSIBLE FOR THE SNOW WILL EXIT THE AREA JUST AS FAST AS IT APPEARED. SNOW SHOULD PRETTY WELL BE OVER BY SUNSET...EXCEPT MAYBE A FEW LINGERING FLURRIES TOWARD MJQ/SPW/SLB. ELECTED NOT TO ISSUE A WIND ADVISORY TODAY...BUT WINDS WILL BE MARGINAL ALONG THE MO VALLEY. 40 TO 50 KT NW FLOW IS IN PLACE AT 850 MB THIS MORNING...BUT DOES NOT APPEAR THESE WINDS WILL BE ABLE TO COMPLETELY MIX TO THE SFC. WOULD LIKE TO SEE SLIGHTLY STRONGER CAA FOR AN ADVISORY. STILL...SHOULD SEE SOME 30 MPH SUSTAINED WINDS WITH GUSTS OVER 40 MPH. CLEARING SKIES WEST TO EAST TONIGHT AND DECREASING WINDS AS HIGH PRESSURE BUILDS INTO THE AREA. COOL HIGH PRESSURE REMAINS IN PLACE TOMORROW...WITH TEMPERATURE ONLY RISING INTO THE 30S IN THE EAST AND 40S WEST. ALTHOUGH THIS IS SOME OF THE COOLEST AIR WE HAVE SEEN THIS SEASON...IT IS RIGHT AROUND NORMAL. NOT MUCH GOING ON IN THE WAY OF WEATHER THOUGH EARLY NEXT WEEK. UPPER RIDGE TO KEEP THINGS DRY THROUGH SATURDAY. A TROUGH DROPS INTO THE NORTHERN PLAINS ON SUNDAY...WHICH COULD BRING SOME LIGHT SNOW SHOWERS TO THE AREA...HOWEVER THERE MAY NOT MUCH MOISTURE TO WORK AND LOOKS LIKE THE NRN STREAM WAVE MAY BE WEAK...WITH STRONGER SRN STREAM WAVE OVER TX. 97 && .AVIATION... AREAS MVFR CIGS AND GUSTY NWLY WINDS WILL FOLLOW A COLD FRONT MOVING SOUTHEAST ACROSS THE AREA EARLY THIS MORNING. THE UPPER LEVEL WAVE DRIVING THE COLD FRONT WILL PRODUCE PERIODS OF LIGHT RAIN OR SNOW SHOWERS...MAINLY EAST OF INTERSTATE 29...TAPERING OFF AFTER 21Z AS THE UPPER WAVE MOVES SOUTHEAST OF THE REGION. PERIODS OF MVFR VSBYS IN -SHSN POSSIBLE AT KHON/KFSD TAF LOCATIONS...WITH BETTER CHANCE OF IFR VSBYS XPCTD TO REMAIN OVER SWRN MN/NWRN IA. WND GUSTS OF 25-35KT BEHIND THE COLD FRONT WILL PERSIST MUCH OF THE DAY...DMNSHG AFTER 26/00Z AS HIGH PRESSURE BEGINS TO BUILD INTO THE AREA FROM THE WEST. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...NONE. MN...NONE. IA...NONE. NE...NONE. $$
