Area Forecast Discussion
Issued by NWS Grand Rapids, MI

Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS63 KGRR 252029 AFDGRR AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND RAPIDS MI 329 PM EST SUN JAN 25 2015 LATEST UPDATE... SYNOPSIS/SHORT TERM/LONG TERM/HYDRO .SYNOPSIS... ISSUED AT 328 PM EST SUN JAN 25 2015 FAIR WEATHER WILL PREVAIL THROUGH MONDAY. SOME LIGHT SNOW IS POSSIBLE MONDAY NIGHT AND TUESDAY BUT SHOULD NOT AMOUNT TO MUCH. A CLIPPER WILL BRING A CHANCE OF SNOW OR MIXED PRECIPITATION WEDNESDAY NIGHT AND THURSDAY. && .SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT) ISSUED AT 328 PM EST SUN JAN 25 2015 ONLY FORECAST ISSUES IN THE NEAR TERM ARE FOR THE EXTENT OF LIGHT SNOW MONDAY NIGHT AND P TYPE ISSUES WEDNESDAY NIGHT. SHALLOW ARCTIC AIR MASS WILL BE IN PLACE TONIGHT AND EXPECT CLEARING TO WORK SOUTH THIS EVENING AS STRONG CAA CONTINUES, DEW POINTS ARE NEAR ZERO ACROSS NORTHERN LOWER MICHIGAN THIS AFTERNOON AND THIS VERY DRY AIR WILL BE MOVING SOUTH. EXPECT LOWS IN THE SINGLE NUMBERS BY DAYBREAK IN MOST PLACES. UPPER TROUGH AMPLIFIES AND GOES NEGATIVE TILT TONIGHT THEN CLOSES OFF ON MONDAY AS BIG NOREASTER HITS NEW ENGLAND. A COUPLE OF QUICK MOVING VORT MAXES ARE PROGGED TO MOVE ACROSS LOWER MICHIGAN MONDAY NIGHT AS WEAK SHORTWAVE TROUGHS HELP FURTHER ENERGIZE THE LARGER SCALE TROUGH. THESE COULD PROVIDE ENOUGH LIFT TO PRODUCE SOME LIGHT SNOW...BUT IT SHOULD BE FAIRLY LIGHT AS SYNOPTIC FORCING IS WEAK. THE NEXT CLIPPER ARRIVES WEDNESDAY NIGHT. THERE IS GOOD AGREEMENT WITH TRACK AND TIMING IN THE 12Z GUIDANCE...THOUGH THE ECMWF IS A BIT WARMER THAN THE GFS. LOOKS LIKE MIXED PRECIP TO START OFF WITH WEDNESDAY EVENING ACROSS THE SOUTHERN HALF OF THE FORECAST AREA GOING OVER TO MORE SNOW LATER WEDNESDAY NIGHT PER THICKNESS TOOLS AND MODEL SOUNDINGS. .LONG TERM...(WEDNESDAY THROUGH SUNDAY) ISSUED AT 328 PM EST SUN JAN 25 2015 THE FOCUS OF THE LONG TERM PORTION OF THE FCST IS ON A COUPLE OF CLIPPER SYSTEMS CENTERED AROUND WED NIGHT/THU AND ON SAT. THESE COULD EACH BRING SOME ACCUMULATING SNOW TO THE AREA. THE SAT CLIPPER COULD END UP USHERING IN A PRETTY GOOD SURGE OF ARCTIC AIR ACROSS THE AREA. THE FIRST CHC OF PCPN WILL COME IN WED NIGHT AND THU WITH A CLIPPER SYSTEM EXPECTED TO MOVE ACROSS THE REGION. WE WILL SEE THE LONG WAVE RIDGE SET UP ACROSS THE WRN STATES AND WE WILL BE UNDER THE INFLUENCE OF THE LONG WAVE TROUGH ESTABLISHED ACROSS THE EAST. ONE OF THE WAVES RIDING IN IS EXPECTED TO GO JUST SOUTH OF THE STATE. THIS LOOKS LIKE MAINLY LIGHT SNOW WITH SOME ACCUMULATIONS. HOWEVER IF THE SYSTEM TRACKS MUCH FURTHER NORTH...WE COULD SEE A WINTRY MIX WITH WARM ENOUGH ALOFT COMING IN. WE WILL SEE A BREAK IN THE WEATHER THEN FOR THU NIGHT THROUGH FRI NIGHT AS SOME SHORT WAVE RIDGING BUILDS IN ACROSS THE AREA. SOME LAKE EFFECT SNOW SHOWERS WILL BE POSSIBLE FOR NNW FLOW AREAS. HOWEVER THE RIDGE WILL LIMIT THE DEPTH OF THE INVERSION AND MOISTURE...SO NO SIGNIFICANT LAKE EFFECT IS EXPECTED THEN. THE NEXT SYSTEM WILL THEN BRING THE NEXT CHC OF SNOW TO THE AREA DURING THE DAY ON SAT. THE MODELS HAVE GENERALLY SHOWN THIS WAVE COMING THROUGH ON SAT AND DRAGGING A NICE CHUNK OF ARCTIC AIR BEHIND IT. WE WILL CONTINUE WITH THIS THOUGHT EVEN WITH AN OUTLIER APPEARING IN THE 12Z MODEL SUITE BRINGING WARMER AIR TO THE AREA. WE ARE BEING SOMEWHAT CONSERVATIVE WITH THE COLD AIR BEHIND THE SYSTEM AT THIS TIME. && .AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON) ISSUED AT 1236 PM EST SUN JAN 25 2015 LIGHT SNOW THAT HAS BEEN AFFECTING THE I-94 TERMINALS THIS MORNING AND EARLY AFTERNOON WILL GRADUALLY MOVE OUT THIS AFTERNOON AND CONDITIONS WILL GENERALLY IMPROVE. WE EXPECT MAINLY MVFR CONDITIONS WITH SOME PATCHY IFR EMBEDDED IN THE LIGHT SNOW. OTHERWISE...NRN AREAS ARE MAINLY VFR RIGHT NOW. SOME LAKE EFFECT CLOUD COVER FROM LAKE HURON BASED AROUND 2000-2500 FT IS AFFECTING KLAN AND KAMN AREAS. KGRR RADAR IS SHOWING SOME OF THIS APPROACHING THE KGRR TERMINAL. THIS MVFR DECK WILL LINGER AROUND AT KLAN AND KGRR THROUGH MOST OF THE AFTERNOON BEFORE IT DIMINISHES AS WINDS DIMINISH THIS EVENING. ONCE THE MVFR CONDITIONS MOVE OUT THIS EVENING...WE ONLY EXPECT SOME MID/HIGH CLOUD COVER THEN THROUGH THE END OF THE FCST PERIOD. && .HYDROLOGY... ISSUED AT 328 PM EST SUN JAN 25 2015 MOST RIVERS ARE HOLDING STEADY OR DROPPING. COLD TEMPERATURES FOR THE COMING WEEK WILL KEEP THE ICE LOCKED UP. CURRENTLY NO SUSPECTED ICE JAMS IN THE AREA... BUT WILL CONTINUE MONITORING FOR ANY THAT DO DEVELOP. SERIOUS ICE JAMS AND FLOODING CONCERNS ARE UNLIKELY UNTIL A SIGNIFICANT WARM UP AND RAINFALL. && .GRR WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...NONE. && $$ SYNOPSIS...OSTUNO SHORT TERM...OSTUNO LONG TERM...NJJ AVIATION...NJJ HYDROLOGY...CAS

USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.