FXUS63 KGRR 251458
AFDGRR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1000 AM EST FRI DEC 25 2009
LATEST UPDATE...SHORT TERM...
.SYNOPSIS...(318 AM EST FRI DEC 25 2009)
FREEZING RAIN AND SLEET WILL GRADUALLY TRANSITION TO RAIN TODAY AS
TEMPERATURES SLOWLY CREEP ABOVE FREEZING. COLDER AIR MOVES BACK IN
TONIGHT WITH SNOW SHOWERS STARTING THIS EVENING AND LASTING OVER THE
WEEKEND.
&&
.SHORT TERM...(1000 AM EST FRI DEC 25 2009)
(TODAY THROUGH SUNDAY)
THE FCST IS RUNNING RIGHT ON TRACK AND NO SIGNIFICANT CHANGES OR
HEADLINE CHANGES ARE PLANNED THIS MORNING. KGRR RADAR TRENDS AND SFC
OBS SHOW FREEZING RAIN AS WELL AS SOME LIGHT SNOW AND POSSIBLY SLEET
IMPACTING OUR NORTHERN/NE CWFA. TEMPS ARE STILL HOVERING AROUND
FREEZING MARK AT SOME SPOTS INCLUDING MOP. SO WE WILL LET THE WINTER
WX ADVISORY HEADLINE GO UNCHANGED THROUGH 18Z THIS AFTERNOON.
REMAINDER OF PREVIOUS SHORT TERM FCST DISCUSSION FOLLOWS... GRADUAL
IMPROVEMENT FROM NORTH TO SOUTH AS WINDS GO A LITTLE MORE
SOUTHEAST AND DEW POINTS AND TEMPS RISE INTO THE MID TO UPPER 30S BY
AFTERNOON. ICY SPOTS WILL PROBABLY REMAIN MOST OF THE DAY UP NORTH.
TREATED PAVEMENT SHOULD BE JUST WET...UNTREATED PAVEMENT WILL BE ICY.
COLDER AIR WILL WRAP IN FROM THE SOUTH SOUTHWEST BY LATE AFTERNOON
WITH ANY RAIN CHANGING TO SNOW BY EVENING...BUT THE DRY SLOT SHOULD
MEAN PRECIP WILL BE LIGHT. TEMPS GO BACK BELOW FREEZING THIS EVENING
BUT SHOULD NOT FALL TOO FAR...SO TREATED ROADS SHOULD ONCE AGAIN
JUST BE WET.
THE SLOW MOVING UPPER LOW PERFORMS A LOOP AROUND THE SFC LOW THEN
FINALLY MOVES EAST AND ARRIVES SATURDAY NIGHT AND INTO SUNDAY WITH
AN INCREASE IN COVERAGE OF LIGHT SNOW. RAISED POPS A BIT FOR
SATURDAY NIGHT.SOME LAKE ENHANCEMENT BECOMES POSSIBLE DURING SUNDAY
AS WINDS BACK TO THE WEST. SOME ACCUMULATIONS POSSIBLE...BUT SHOULD
BE LIMITED TO THE 1 TO 3 INCH RANGE IN MOST PLACES.
&&
.LONG TERM...(318 AM EST FRI DEC 25 2009)
(SUNDAY NIGHT THROUGH THURSDAY)
THE MID RANGE MODELS ARE IN DECENT AGREEMENT IN A SETUP WITH SLOW
MOVING SYSTEMS. SOLUTIONS ARE A BIT QUICKER THAN PREVIOUS VERSIONS
AND START AND END TIMES OF PRECIPITATION EVENTS ARE THE MAIN
CHALLENGES. ONLY SMALL CHANGES NEEDED TO GRIDS.
THE AREA WILL BE EXPERIENCING LAKE EFFECT SNOW SHOWERS AS A LOW
PRESSURE SYSTEM MOVES OUT OF THE REGION SUNDAY NIGHT INTO MONDAY
NIGHT. DELTA T/S WILL BE IN THE 12 TO 16 DEGREE C RANGE WITH 850
TEMPERATURES AROUND -10 C. WINDS WILL BE OUT OF THE NORTHWEST...
WHICH SHOULD RESULT IN THE HEAVIEST SNOWS OVER AREAS SOUTH AND WEST
OF GRAND RAPIDS.
DRY WEATHER WILL MOVE IN SOMETIME MONDAY NIGHT OR EARLY TUESDAY AS
AN AREA OF HIGH PRESSURE MOVES INTO THE REGION AND THE FLOW BECOMES
ANTICYCLONIC. THE NEXT LOW WILL APPROACH THE AREA LATE WEDNESDAY OR
WEDNESDAY NIGHT AND SNOW WILL BE POSSIBLE AS THIS FEATURE SLOWLY
MOVES BY TO THE NORTH THROUGH THURSDAY. AT THIS TIME... THE SNOW
LOOKS TO BE LIGHT.
$$
.AVIATION...(628 AM EST FRI DEC 25 2009)
BATCH OF HEAVY RAIN MOVING NORTH THIS MORNING WITH FREEZING RAIN
PERSISTING UNTIL ABOUT 14Z AT GRR...LAN AND MKG. THEN THE DRY SLOT
MOVES IN FOR THIS AFTERNOON WITH ONLY SCATTERED SHOWERS WHICH WILL
BE CHANGING TO SNOW THIS EVENING AS COLDER AIR MOVES IN. MVFR
CEILINGS FOR THE MOST PART TODAY WITH SOME IFR AT TIMES.
&&
.MARINE...(318 AM EST FRI DEC 25 2009)
GALE WARNING TODAY WITH OFFSHORE WINDS TO 35 KNOTS AND HIGHEST WAVES
BUILDING OUT IN THE OPEN WATERS. WINDS WILL SLOWLY DIMINISH THIS
AFTERNOON AND TONIGHT.
&&
.HYDROLOGY...(318 AM EST FRI DEC 25 2009)
TEMPERATURES IN THE 30S WILL PREVENT MUCH LOSS OF SNOWPACK TODAY SO
RIVER LEVELS SHOULD NOT RISE MUCH OVER THE WEEKEND.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WINTER WEATHER ADVISORY THROUGH 18Z FOR THE NORTHEAST FORECAST
AREA.
LM...GALE WARNING THROUGH THIS AFTERNOON FOR THE ENTIRE NEAR SHORE.
&&
$$
SYNOPSIS: OSTUNO
SHORT TERM: OSTUNO/LAURENS
LONG TERM: 69
AVIATION: OSTUNO
MARINE: OSTUNO
HYDROLOGY: OSTUNO
