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 251153 AFDGRR AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GRAND RAPIDS MI 753 AM EDT SAT OCT 25 2014 LATEST UPDATE... AVIATION .SYNOPSIS... ISSUED AT 336 AM EDT SAT OCT 25 2014 A RATHER BREEZY DAY CAN BE EXPECTED TODAY AS A COLD FRONT SWEEPS THROUGH THE AREA. NO PRECIPITATION IS EXPECTED WITH THE FRONTAL PASSAGE. HIGHS WILL PUSH INTO THE LOWER 60S TODAY WHICH IS ACTUALLY ABOVE NORMAL FOR THIS TIME OF YEAR. HIGHS WILL ONLY REACH THE 50S ON SUNDAY WITH DRY AND FAIR WEATHER EXPECTED. A WARM FRONT SURGING INTO THE REGION WILL BRING SHOWERS AND STORMS TO THE AREA FOR SUNDAY NIGHT INTO MONDAY. HIGHS ON MONDAY WILL PUSH INTO THE LOWER 70S ACROSS SOUTHERN LOWER MICHIGAN. ADDITIONAL SHOWERS AND STORMS ARE EXPECTED MONDAY NIGHT INTO TUESDAY MORNING. MUCH COOLER WEATHER WILL SETTLE INTO THE AREA FOR THE LATTER HALF OF THE UPCOMING WORK WEEK. && .SHORT TERM...(TODAY THROUGH MONDAY) ISSUED AT 336 AM EDT SAT OCT 25 2014 LIMITED WEATHER CONCERNS TODAY THROUGH SUNDAY AS A COLD FRONT PASSES THROUGH DRY TODAY AND HIGH PRESSURE BUILDS IN FOR TONIGHT AND SUNDAY. SKIES WILL GRADUALLY CLEAR OUT TODAY WITH INCREASING AMOUNTS OF SUNSHINE AS WE MOVE THROUGH THE AFTERNOON. MAINLY CLEAR SKIES ARE EXPECTED TONIGHT AND SUNDAY. THE MAIN FOCUS OF THE SHORT TERM IS ON CHANCES FOR SHOWERS AND STORMS AS A WARM FRONT MOVES IN SUNDAY NIGHT. 30-40 PCT POPS AREA WIDE FOR SHOWERS AND STORMS SEEMS REASONABLE SUNDAY NIGHT GIVEN THE SURGE OF MOISTURE. 850MB DEW POINTS RISE RAPIDLY INTO THE LOWER TEENS C. RISES OF THE MAGNITUDE FORECAST FOR SUNDAY NIGHT USUALLY RESULT ON DECENT COVERAGE OF CONVECTION. THE 850MB MOISTURE TRANSPORT IS NOT OFF THE CHARTS...BUT IS SOLID...AS IS THE LLJ. A 30KT LLJ IS NOSING IN MONDAY MORNING. THE LLJ RAMPS UP FURTHER ON MONDAY WITH 35-40 KNOTS IN PLACE FOR THE AFTERNOON. CONTINUED THE CHANCE POPS AREA WIDE FOR MONDAY. DEEP LAYER MOST UNSTABLE CAPE VALUES ALSO SUPPORT THUNDERSTORM CHANCES BOTH PERIODS (SUNDAY NIGHT AND MONDAY). AT THIS POINT NOT EXPECTING ANYTHING SEVERE. SHEAR VALUES ARE DECENT BOTH SUNDAY NIGHT AND MONDAY...BUT THE MAX IS REACHED A DAYBREAK ON MONDAY WHICH IS A USUAL RELATIVE MINIMUM IN SEVERE ACTIVITY. 0-6KM BULK SHEAR REACHES 50 KNOTS. .LONG TERM...(MONDAY NIGHT THROUGH FRIDAY) ISSUED AT 336 AM EDT SAT OCT 25 2014 THE MODELS REMAIN ON THE SAME PAGE...SHOWING A STRONG COLD FRONT COMING THROUGH SW MI TUESDAY MORNING. THIS SYSTEM WILL HAVE GOOD JET DYNAMICS IN THE LOWER AND UPPER ATMOSPHERE...SO EXPECT LIKELY TO HIGH CHANCE POPS WILL WORK WITH THIS FROPA. THE MODELS CONTINUE TO TREND COLDER BEHIND THE FRONT...SO TUESDAY AFTERNOON SHOULD SEE FALLING TEMPS FROM A MORNING HIGH IN THE UPPER 50S TO MID 60S. WE SHOULD SEE A BRIEF PERIOD OF LAKE EFFECT LATE TUESDAY NIGHT/EARLY WEDNESDAY AS H8 TEMPS PLUNGE TO AROUND -3C. THIS SHOULD BE A SHORT WINDOW HOWEVER AS ANTICYCLONIC FLOW DEVELOPS BY MID DAY WEDNESDAY ALONG WITH SURFACE HIGH PRESSURE BUILDING IN. THEN A SHARPENING SHORT WAVE IS PROGGED TO REACH THE REGION BY THURSDAY NIGHT. H8 TEMPS DROP EVEN FURTHER BEHIND THIS SYSTEM TO AROUND -7C BY FRIDAY. BELIEVE WE STAND A CHANCE OF SEEING RAIN...POSSIBLY MIXED WITH OR CHANGING TO SNOW OVER THE INTERIOR NORTH THURSDAY NIGHT INTO FRIDAY. WE WILL HAVE TO SEE IF THIS COLDER TREND CONTINUES...IF SO WE WILL HAVE TO EXPAND THE MENTION OF SNOW FURTHER SOUTH. && .AVIATION...
-- Changed Discussion --
(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING) ISSUED AT 750 AM EDT SAT OCT 25 2014 SOME MVFR CLOUDS REMAIN ACROSS SOUTHWEST LOWER MICHIGAN AT 12Z...BUT THE TREND WILL BE TO CLEAR THESE OUT THROUGH THE COURSE OF THE MORNING. BY NOON...EXPECTING MOST AREAS TO BE MOSTLY CLEAR. CLEAR SKIES ARE THEN ANTICIPATED WITH VFR CONDITIONS PERSISTING FROM THIS AFTERNOON THROUGH THE NIGHT. THE OTHER MAIN STORY WILL BE THE GUSTY WESTERLY WINDS TODAY. FROM ABOUT 15Z THROUGH 23Z...12-25 KNOT WEST WINDS CAN BE EXPECTED WITH A FEW POSSIBLE GUSTS TOWARDS 30 KNOTS.
-- End Changed Discussion --
&& .MARINE... ISSUED AT 336 AM EDT SAT OCT 25 2014 OPTED TO ISSUE A SMALL CRAFT ADVISORY FROM LATE THIS AFTERNOON THROUGH SUNDAY AFTERNOON. NORTHWEST WINDS BEHIND A COLD FRONTAL PASSAGE THIS MORNING WILL RISE INTO THE 15 TO 25 KNOT RANGE. THE CORE OF THE WIND IS EXPECTED TO MOVE THROUGH THE AREA THIS EVENING. WAVES WILL LIKELY PEAK IN THE 4 TO 6 FOOT RANGE. WINDS AND WAVES WILL SUBSIDE SUBSTANTIALLY SUNDAY AFTERNOON INTO SUNDAY EVENING AS HIGH PRESSURE BUILDS IN. && .HYDROLOGY... ISSUED AT 336 AM EDT SAT OCT 25 2014 NO HYDRO CONCERNS ARE ANTICIPATED THROUGH THE NEXT 3 TO 5 DAYS. THAT SAID...SHOWER AND THUNDERSTORMS ARE EXPECTED IN THE SUNDAY NIGHT THROUGH TUESDAY TIME FRAME. RAINFALL AMOUNTS DURING THIS PERIOD WILL LIKELY RANGE FROM AROUND A QUARTER OF AN INCH TO AROUND THREE QUARTERS OF AN INCH. WITH RIVER LEVELS CURRENTLY AROUND NORMAL AND WELL WITHIN BANK WE DO NOT ANTICIPATE ANY RIVER OR FLOOD ISSUES. PWAT VALUES ARE STILL EXPECTED TO RISE TO AROUND 1.25 INCHES...SO THERE WILL BE SOME LOCALLY HEAVY DOWNPOURS WITH STORMS. && .GRR WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
MI...NONE. LM...SMALL CRAFT ADVISORY FROM 5 PM THIS AFTERNOON TO 5 PM EDT SUNDAY FOR LMZ844>849.
-- End Changed Discussion --
&& $$ SYNOPSIS...DUKE SHORT TERM...DUKE LONG TERM...JK AVIATION...DUKE HYDROLOGY...DUKE MARINE...DUKE

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