RSS FeedsIssued by NWS Grand Forks, ND
000 FXUS63 KFGF 240330 AFDFGF AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND FORKS ND 930 PM CST MON NOV 23 2009 .UPDATE... SFC LOW AT 03Z NEAR KTVF. AREA OF RAIN ON NORTSIDE OF 500 MB UPPER LOW WHICH IS NEAR GRAND FORKS MOVING NORTHWARD INTO SOUTHEAST MANITOBA WITH THE LINGERNIG RAIN OVER FAR NE ND/NW MN EXITING THE AREA BY 06Z WITH THE EXCEPTION OF THE LAKE OF THE WOODS REGION WHICH WILL STAY CLOSER TO THE RAIN AREA THROUGH 09Z. THAT LEAVES MOST OF THE FCST AREA SEEING NOT TOO MUCH THE REST OF THE NIGHT BUT WILL MAINTAIN CHC POPS OVER MINNESOTA FCST AREA DUE TO AREAS OF DRIZZLE AND TO THE WRN EDGE OF THE NEXT AREA OF LIGHT RAIN MOVING INTO SE SD/SW MN ATTM. THIS AREA IS PROGGED TO CLIP FAR SOUTHEASTERN FCST AREA LATER TONIGHT-TUES MORNING. IN ERN ND ISSUES WILL BE CLEARING...FOG AND LOW TEMPS. WRN EDGE OF LOW CLOUD CLEARING TRYING EVER SO SLOWLY TO EDGE INTO THE LANGDON-LAKOTA- COOPERSTOWN-VALLEY CITY AREAS. RUC MODEL SHOWS 925 MB MOISTURE CLEARING A BIT THROUGH THE NIGHT WITH LOW CLD CLEARING REACHING THE RED RIVER AREAS TOWARD 12Z. IF IT DOES CLEAR OUT IN THE RED RIVER VALLEY BY MORNING WITH LIGHT WIND AND RAIN TODAY FOG WILL SURELY FORM AND IT COULD BE DENSE. WILL MAINTAIN AREAS OF FOG CWA WIDE OVERNIGHT INTO TUES 15Z AS PREV FCST HAD. MENTIONED 1/2SM PSBL IN TAFS AT GFK/FAR/TVF/BJI. && .AVIATION...TOUGH CALL FOR THE 12Z PERIOD FOR FARGO-GRAND FORKS TAF SITES. LOW CLOUDS MAY CLEAR OUT FOR A WHILE...BUT IF IT DOES WOULD EXPECT FOG AND LOW CLOUDS TO REFORM DUE TO WET GROUND AND LIGHT WINDS. SO OVERALL NOT TO OPTIMISTIC FOR ANYTHING BUT IFR AND MAYBE LOW MVFR CONDITIONS THRU 15Z TUES. LOW LEVEL DRY OUT TUESDAY SO ONCE ANY LOW LEVEL CLOUDS/FOG GOES AWAY JUST SOME CIRRUS OR MID CLOUD. TVF AND BJI SHOULD STAY WITH LOW CLOUDS THROUGH THE MID MORNING HOURS ON TUESDAY WITH CLEARING IN THE AFTN. SOME FOG POTENTIAL THESE AREAS WITH LIGHT WINDS. MENTIONED 1/2SM IN TEMPO GROUPS THESE 4 TAF SITES AROUND 12Z. DVL AREA IS CLEAR NOW AND DID NOT GET RAIN TODAY AND KEPT THEM VFR WITHOUT ANY FOG. && .PREV DISCUSSION... /ISSUED 250 PM CST MON NOV 23 2009/ SHORT TERM... THE MAIN FORECAST CHALLENGE IS PCPN. WHEN LOOKING AT THE LATEST SURFACE ANALYSIS...AN AREA OF LOW PRESSURE IS CENTERED NEAR BWP...WITH AN INVERTED TROF EXTENDING THROUGH THE RED RIVER VALLEY. WHEN LOOKING AT THE MODELS...THE MODELS REMAIN IN PRETTY GOOD AGREEMENT WITH THE TRACK AND TIMING OF THE LOW AND ITS ASSOCIATED PCPN THROUGH THE AREA TONIGHT. THUS...ENDED UP USING A MODEL BLEND FOR THE FORECAST...LEANING TOWARD THE NAM FOR POPS AND THE ADJMAV FOR TEMPS. RADAR IMAGERY SHOWS AN AREA OF RAIN MAINLY ACROSS NE ND AND NW MN...MOVING TO THE N. WITH THE BEST 850MB Q-VECTOR CONVERGENCE AND 700MB LIFT MOVING NE TONIGHT WITH THE LOW...EXPECT RAIN TO END FROM W TO E...WITH SOME LINGERING RAIN TOMORROW IN THE PKD-BDE AREAS. A CLIPPER SYSTEM QUICKLY FOLLOWS FOR TUE NIGHT...BRINGING A CHANCE FOR PCPN TO MUCH OF E ND...NW AND WC MN. WITH THE ATMOSPHERIC COLUMN DROPPING BELOW FREEZING AS THIS SYSTEM APPROACHES...EXPECT THE PCPN TO BE SNOW...WITH WINDY CONDITIONS DEVELOPING DURING THE DAY ON WED AS THIS CLIPPER PASSES. WITH THIS CLIPPER PASSING QUICKLY...ANTICIPATE SNOWFALL AMOUNTS AT THIS TIME TO BE AROUND ONE INCH BY THU MORNING. A RIDGE OF HIGH PRESSURE IS EXPECTED TO BUILD IN FOR THANKSGIVING DAY...KEEPING THE N PLAINS DRY WITH A LITTLE COOLER TEMPERATURES. LONG TERM [THU NIGHT-SUN]... THE MAIN CHALLENGES IN THE LONG TERM INCLUDE DETERMINING PCPN CHANCES ASSOCIATED WITH A LONG WAVE TROUGH THAT WILL CROSS THE CENTRAL UNITED STATES THIS WEEKEND INTO EARLY NEXT WEEK...AS WELL AS TEMPERATURES EARLY NEXT WEEK. THERE ARE SIGNIFICANT MODEL DIFFERENCES ARISING FROM THE WAY THE STRENGTHEN THE LONG WAVE TROUGH AS IT PASSES OVER THE ROCKIES...WHICH IN TURN AFFECTS WHERE THE MODELS FOCUS THE SURFACE LOW PRESSURE OVER THE CENTRAL UNITED STATES. THE LATEST ECMWF IS MUCH DIFFERENT THAN ITS PREVIOUS RUN AND FOCUSES THE SURFACE PRESSURE ACROSS THE S U.S. THE GEM AND GFS ARE NOW MORE SIMILAR...BUT THE GEM SEEMS A LITTLE FAST. THEREFORE...THE GFS WAS THE PREFERRED MODEL. THU NIGHT THROUGH FRI NIGHT LOOKS DRY AS HIGH PRESSURE INFLUENCES THE REGION. THE GEM BRINGS PCPN INTO THE REGION AS EARLY AS SAT...BUT THINK THIS IS TOO FAST. THEREFORE...KEPT SAT DRY AND BEGAN PCPN CHANCES SAT NIGHT. ALL THE MODELS LOOK COOL ENOUGH TO INDICATE ALL SNOW. COLD AIR SHOULD THEN FOLLOW UP ANY PASSING LOW PRESSURE SYSTEM EARLY NEXT WEEK. && .FGF WATCHES/WARNINGS/ADVISORIES... ND...NONE. MN...NONE. && $$ RIDDLE/NG
