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000
FXUS63 KGRR 281150
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
650 AM EST SAT FEB 28 2015

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 330 AM EST SAT FEB 28 2015

WEAK LOW PRESSURE WILL MOVE ACROSS SOUTHERN LOWER MICHIGAN THIS
EVENING AND SUNDAY SPREADING LIGHT SNOW AS IT MOVES EAST.
ACCUMULATIONS WILL BE LIMITED TO 1 TO PERHAPS 3 INCHES...HIGHEST
SOUTH OF I-94. A MORE SUBSTANTIAL SYSTEM WILL AFFECT LOWER MICHIGAN
MONDAY NIGHT AND TUESDAY. THE POTENTIAL EXISTS FOR MIXED FREEZING
RAIN...SLEET...AND SOME SNOW. TEMPERATURES WILL WARM INTO THE MID
30S TUESDAY BUT QUICKLY FALL INTO THE TEENS BY THURSDAY.

&&

.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 330 AM EST SAT FEB 28 2015

FORECAST CONCERNS DEAL WITH SNOW POTENTIAL TONIGHT/SUNDAY.
OVERALL...THE FORECAST DIDN/T CHANGE MUCH.

WE/LL START OFF MOSTLY SUNNY THIS MORNING BUT CLOUDS WILL BEGIN TO
SPREAD OVER THE CWA BY LATE IN THE AFTERNOON AS A COUPLE OF SHORT
WAVES MOVE IN THIS DIRECTION. BOTH OF THESE WAVES WILL MOVE JUST
SOUTH OF THE CWA BUT JET DYNAMICS WILL HELP TO PULL THE LIGHT SNOW
NORTHWARD. WE/LL SEE LIGHT SNOW DEVELOP BY 04Z SOUTH OF I-94 AND
THEN GRADUALLY SPREAD NORTHWARD TO NEAR I-96 AFTER MIDNIGHT. THIS
ISN`T AN IMPRESSIVE SYSTEM AND TOTAL SNOW SHOULD RANGE FROM AROUND
AN INCH NEAR I-96 TO PERHAPS AS HIGH AS 3 INCHES SOUTH OF I-94. SNOW
WILL END SUNDAY NIGHT AS THE SECOND WAVE MOVES EAST AND HIGH
PRESSURE WILL BUILD IN TO THE GREAT LAKES MONDAY.

.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 330 AM EST SAT FEB 28 2015

WE CONTINUE TO EXPECT A MESSY SYSTEM TO COME THROUGH ON TUESDAY WITH
A POTENTIALLY HAZARDOUS MIXTURE OF SNOW...SLEET AND FREEZING RAIN.
THE PRECIPITATION SHOULD CHANGE OVER TO MAINLY RAIN FOR A TIME SOUTH
OF I-96 TUESDAY AFTERNOON AND EVENING.

WE HAVENT SEEN MUCH IMPACT FROM THE SOUTHERN STREAM OF THE JET THIS
WINTER IN MICHIGAN AND THAT LOOKS TO CHANGE VERY BRIEFLY EARLY NEXT
WEEK AS IT LIFTS NORTH IN RESPONSE TO A DEEP WEST COAST TROUGH. WIND
SPEEDS WITHIN THE UPPER JET ARE PROGGED TO BE 150 KTS OR MORE WITH
SOME POTENTIAL FOR A PERIOD OF COUPLED JET OR RIGHT ENTRANCE REGION
FORCING. THE LOW LEVEL JET IS PROGGED TO BE 50-70 KTS WHICH SENDS
PWATS OF AN INCH OR MORE NORTHWARD FROM THE GULF.

THIS LOOKS LIKE A RELATIVELY QUICK HITTING EVENT WITH MOST OF THE
PRECIP COMING IN A 12 HOUR PERIOD ON THE NOSE OF THE LOW LEVEL JET.
SUSPECT MUCH OF THIS PRECIP WILL BE CONVECTIVE IN NATURE SO HEAVY
PRECIP RATES ARE POSSIBLE BEFORE A DRY SLOT SWEEPS IN FROM THE
SOUTHWEST LATE TUESDAY/TUESDAY EVENING.

THE FREEZING RAIN/ICING POTENTIAL SHOULD BE HIGH GIVEN HOW COLD IT
HAS BEEN LATELY AND THAT ROADS/OBJECTS WILL REMAIN COLDER THAN THE
AIR TEMPS FOR THE INITIAL STAGES OF THE EVENT.

BASED ON THE LATEST THERMAL PROFILES IT LOOKS LIKE MOSTLY SNOW LATE
MONDAY NIGHT INTO EARLY TUESDAY MORNING FOLLOWED BY A QUICK CHANGE
TO FREEZING RAIN FOR AREAS NEAR/SOUTH OF I-96 15Z-21Z TUESDAY.
PRIMARILY SNOW EXPECTED NORTH OF I-96 THROUGH THE EVENT...POSSIBLY
MIXED WITH SOME SLEET/FREEZING RAIN. MAINLY RAIN SOUTH OF I-96
21Z-03Z. PRECIP GOES BACK TO ALL SNOW LATE TUESDAY NIGHT ALTHOUGH
MAINLY LIGHT WITH NO SIG ACCUMS EXPECTED.

AFTER THIS SYSTEM THE NORTHERN STREAM DOMINATES AGAIN FOR THE
REMAINDER OF THE WEEK SO MORE COLD AIR WITH OCCASIONAL LIGHT SNOW.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 650 AM EST SAT FEB 28 2015

VFR TODAY INTO THIS EVENING WITH THE EXCEPTION OF SOME MVFR CIGS
AROUND 2500 FT AT MKG THIS MORNING. LIGHT SNOW MOVING IN FROM THE
SOUTH AFTER 04Z TONIGHT WITH MVFR CIGS/VSBYS DEVELOPING. IFR VSBYS
UNDER 3 MILES MORE LIKELY LATE TONIGHT AT AZO/BTL/JXN THAN FARTHER
NORTH AT MKG/GRR/LAN.

&&

.HYDROLOGY...
ISSUED AT 1202 PM EST FRI FEB 27 2015

THE BATTLE CREEK SITE (BTCM4) ON THE KALAMAZOO RIVER HAS SHOWN
SOME ERRONEOUS DATA THROUGH THE MORNING HOURS. THIS HAS BEEN
DETERMINED TO BE CAUSED BY THE EXTREME COLD THAT SETTLED IN
OVERNIGHT. IT HAS SINCE SHOWN SIGNS OF RETURNING BACK TO ITS
ORIGINAL READING AS A RESULT OF THE SUNSHINE THIS AFTERNOON.
COORDINATION WITH LOCAL OFFICIALS HAS NOT REVEALED ANY NEED FOR
CONCERN.

WHILE AREA STREAMS AND RIVERS HAVE BEEN STABLE FOR SEVERAL WEEKS
NOW A RATHER ACTIVE PERIOD AND GRADUAL WARMING TREND IS EXPECTED.
THIS DOES NOT NECESSARILY RAISE ALARM BUT WE SHOULD HEED SPECIFICS
AS TEMPERATURES BEGIN TO INCREASE AND PRECIPITATION APPROACHES.
TOTAL PRECIPITATION THROUGH THE NEXT SEVEN DAYS IS ANTICIPATED TO
REMAIN UNDER AN INCH. THE REAL QUESTION COMES ON TUESDAY...AS TO
THE EXTENT OF WARMTH...PRECIPITATION AMOUNTS AND PRECIPITATION
TYPE. THAT SAID...WE WOULD NEED A MEANINGFUL AMOUNT OF MOISTURE
IN A SHORT PERIOD OF TIME...COUPLED WITH AN EXTENDED PERIOD OF
WARMTH TO CREATE INSTABILITY IN THE CURRENT ICE COVER. AS OF
NOW...NO REAL ISSUES ARE EXPECTED BUT RIVERS WILL BE MONITORED
THROUGH THE NEXT WEEK.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&

$$

SYNOPSIS...04
SHORT TERM...04
LONG TERM...MEADE
AVIATION...MEADE
HYDROLOGY...JAM








000
FXUS63 KGRR 281150
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
650 AM EST SAT FEB 28 2015

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 330 AM EST SAT FEB 28 2015

WEAK LOW PRESSURE WILL MOVE ACROSS SOUTHERN LOWER MICHIGAN THIS
EVENING AND SUNDAY SPREADING LIGHT SNOW AS IT MOVES EAST.
ACCUMULATIONS WILL BE LIMITED TO 1 TO PERHAPS 3 INCHES...HIGHEST
SOUTH OF I-94. A MORE SUBSTANTIAL SYSTEM WILL AFFECT LOWER MICHIGAN
MONDAY NIGHT AND TUESDAY. THE POTENTIAL EXISTS FOR MIXED FREEZING
RAIN...SLEET...AND SOME SNOW. TEMPERATURES WILL WARM INTO THE MID
30S TUESDAY BUT QUICKLY FALL INTO THE TEENS BY THURSDAY.

&&

.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 330 AM EST SAT FEB 28 2015

FORECAST CONCERNS DEAL WITH SNOW POTENTIAL TONIGHT/SUNDAY.
OVERALL...THE FORECAST DIDN/T CHANGE MUCH.

WE/LL START OFF MOSTLY SUNNY THIS MORNING BUT CLOUDS WILL BEGIN TO
SPREAD OVER THE CWA BY LATE IN THE AFTERNOON AS A COUPLE OF SHORT
WAVES MOVE IN THIS DIRECTION. BOTH OF THESE WAVES WILL MOVE JUST
SOUTH OF THE CWA BUT JET DYNAMICS WILL HELP TO PULL THE LIGHT SNOW
NORTHWARD. WE/LL SEE LIGHT SNOW DEVELOP BY 04Z SOUTH OF I-94 AND
THEN GRADUALLY SPREAD NORTHWARD TO NEAR I-96 AFTER MIDNIGHT. THIS
ISN`T AN IMPRESSIVE SYSTEM AND TOTAL SNOW SHOULD RANGE FROM AROUND
AN INCH NEAR I-96 TO PERHAPS AS HIGH AS 3 INCHES SOUTH OF I-94. SNOW
WILL END SUNDAY NIGHT AS THE SECOND WAVE MOVES EAST AND HIGH
PRESSURE WILL BUILD IN TO THE GREAT LAKES MONDAY.

.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 330 AM EST SAT FEB 28 2015

WE CONTINUE TO EXPECT A MESSY SYSTEM TO COME THROUGH ON TUESDAY WITH
A POTENTIALLY HAZARDOUS MIXTURE OF SNOW...SLEET AND FREEZING RAIN.
THE PRECIPITATION SHOULD CHANGE OVER TO MAINLY RAIN FOR A TIME SOUTH
OF I-96 TUESDAY AFTERNOON AND EVENING.

WE HAVENT SEEN MUCH IMPACT FROM THE SOUTHERN STREAM OF THE JET THIS
WINTER IN MICHIGAN AND THAT LOOKS TO CHANGE VERY BRIEFLY EARLY NEXT
WEEK AS IT LIFTS NORTH IN RESPONSE TO A DEEP WEST COAST TROUGH. WIND
SPEEDS WITHIN THE UPPER JET ARE PROGGED TO BE 150 KTS OR MORE WITH
SOME POTENTIAL FOR A PERIOD OF COUPLED JET OR RIGHT ENTRANCE REGION
FORCING. THE LOW LEVEL JET IS PROGGED TO BE 50-70 KTS WHICH SENDS
PWATS OF AN INCH OR MORE NORTHWARD FROM THE GULF.

THIS LOOKS LIKE A RELATIVELY QUICK HITTING EVENT WITH MOST OF THE
PRECIP COMING IN A 12 HOUR PERIOD ON THE NOSE OF THE LOW LEVEL JET.
SUSPECT MUCH OF THIS PRECIP WILL BE CONVECTIVE IN NATURE SO HEAVY
PRECIP RATES ARE POSSIBLE BEFORE A DRY SLOT SWEEPS IN FROM THE
SOUTHWEST LATE TUESDAY/TUESDAY EVENING.

THE FREEZING RAIN/ICING POTENTIAL SHOULD BE HIGH GIVEN HOW COLD IT
HAS BEEN LATELY AND THAT ROADS/OBJECTS WILL REMAIN COLDER THAN THE
AIR TEMPS FOR THE INITIAL STAGES OF THE EVENT.

BASED ON THE LATEST THERMAL PROFILES IT LOOKS LIKE MOSTLY SNOW LATE
MONDAY NIGHT INTO EARLY TUESDAY MORNING FOLLOWED BY A QUICK CHANGE
TO FREEZING RAIN FOR AREAS NEAR/SOUTH OF I-96 15Z-21Z TUESDAY.
PRIMARILY SNOW EXPECTED NORTH OF I-96 THROUGH THE EVENT...POSSIBLY
MIXED WITH SOME SLEET/FREEZING RAIN. MAINLY RAIN SOUTH OF I-96
21Z-03Z. PRECIP GOES BACK TO ALL SNOW LATE TUESDAY NIGHT ALTHOUGH
MAINLY LIGHT WITH NO SIG ACCUMS EXPECTED.

AFTER THIS SYSTEM THE NORTHERN STREAM DOMINATES AGAIN FOR THE
REMAINDER OF THE WEEK SO MORE COLD AIR WITH OCCASIONAL LIGHT SNOW.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 650 AM EST SAT FEB 28 2015

VFR TODAY INTO THIS EVENING WITH THE EXCEPTION OF SOME MVFR CIGS
AROUND 2500 FT AT MKG THIS MORNING. LIGHT SNOW MOVING IN FROM THE
SOUTH AFTER 04Z TONIGHT WITH MVFR CIGS/VSBYS DEVELOPING. IFR VSBYS
UNDER 3 MILES MORE LIKELY LATE TONIGHT AT AZO/BTL/JXN THAN FARTHER
NORTH AT MKG/GRR/LAN.

&&

.HYDROLOGY...
ISSUED AT 1202 PM EST FRI FEB 27 2015

THE BATTLE CREEK SITE (BTCM4) ON THE KALAMAZOO RIVER HAS SHOWN
SOME ERRONEOUS DATA THROUGH THE MORNING HOURS. THIS HAS BEEN
DETERMINED TO BE CAUSED BY THE EXTREME COLD THAT SETTLED IN
OVERNIGHT. IT HAS SINCE SHOWN SIGNS OF RETURNING BACK TO ITS
ORIGINAL READING AS A RESULT OF THE SUNSHINE THIS AFTERNOON.
COORDINATION WITH LOCAL OFFICIALS HAS NOT REVEALED ANY NEED FOR
CONCERN.

WHILE AREA STREAMS AND RIVERS HAVE BEEN STABLE FOR SEVERAL WEEKS
NOW A RATHER ACTIVE PERIOD AND GRADUAL WARMING TREND IS EXPECTED.
THIS DOES NOT NECESSARILY RAISE ALARM BUT WE SHOULD HEED SPECIFICS
AS TEMPERATURES BEGIN TO INCREASE AND PRECIPITATION APPROACHES.
TOTAL PRECIPITATION THROUGH THE NEXT SEVEN DAYS IS ANTICIPATED TO
REMAIN UNDER AN INCH. THE REAL QUESTION COMES ON TUESDAY...AS TO
THE EXTENT OF WARMTH...PRECIPITATION AMOUNTS AND PRECIPITATION
TYPE. THAT SAID...WE WOULD NEED A MEANINGFUL AMOUNT OF MOISTURE
IN A SHORT PERIOD OF TIME...COUPLED WITH AN EXTENDED PERIOD OF
WARMTH TO CREATE INSTABILITY IN THE CURRENT ICE COVER. AS OF
NOW...NO REAL ISSUES ARE EXPECTED BUT RIVERS WILL BE MONITORED
THROUGH THE NEXT WEEK.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&

$$

SYNOPSIS...04
SHORT TERM...04
LONG TERM...MEADE
AVIATION...MEADE
HYDROLOGY...JAM







000
FXUS63 KGRR 281150
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
650 AM EST SAT FEB 28 2015

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 330 AM EST SAT FEB 28 2015

WEAK LOW PRESSURE WILL MOVE ACROSS SOUTHERN LOWER MICHIGAN THIS
EVENING AND SUNDAY SPREADING LIGHT SNOW AS IT MOVES EAST.
ACCUMULATIONS WILL BE LIMITED TO 1 TO PERHAPS 3 INCHES...HIGHEST
SOUTH OF I-94. A MORE SUBSTANTIAL SYSTEM WILL AFFECT LOWER MICHIGAN
MONDAY NIGHT AND TUESDAY. THE POTENTIAL EXISTS FOR MIXED FREEZING
RAIN...SLEET...AND SOME SNOW. TEMPERATURES WILL WARM INTO THE MID
30S TUESDAY BUT QUICKLY FALL INTO THE TEENS BY THURSDAY.

&&

.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 330 AM EST SAT FEB 28 2015

FORECAST CONCERNS DEAL WITH SNOW POTENTIAL TONIGHT/SUNDAY.
OVERALL...THE FORECAST DIDN/T CHANGE MUCH.

WE/LL START OFF MOSTLY SUNNY THIS MORNING BUT CLOUDS WILL BEGIN TO
SPREAD OVER THE CWA BY LATE IN THE AFTERNOON AS A COUPLE OF SHORT
WAVES MOVE IN THIS DIRECTION. BOTH OF THESE WAVES WILL MOVE JUST
SOUTH OF THE CWA BUT JET DYNAMICS WILL HELP TO PULL THE LIGHT SNOW
NORTHWARD. WE/LL SEE LIGHT SNOW DEVELOP BY 04Z SOUTH OF I-94 AND
THEN GRADUALLY SPREAD NORTHWARD TO NEAR I-96 AFTER MIDNIGHT. THIS
ISN`T AN IMPRESSIVE SYSTEM AND TOTAL SNOW SHOULD RANGE FROM AROUND
AN INCH NEAR I-96 TO PERHAPS AS HIGH AS 3 INCHES SOUTH OF I-94. SNOW
WILL END SUNDAY NIGHT AS THE SECOND WAVE MOVES EAST AND HIGH
PRESSURE WILL BUILD IN TO THE GREAT LAKES MONDAY.

.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 330 AM EST SAT FEB 28 2015

WE CONTINUE TO EXPECT A MESSY SYSTEM TO COME THROUGH ON TUESDAY WITH
A POTENTIALLY HAZARDOUS MIXTURE OF SNOW...SLEET AND FREEZING RAIN.
THE PRECIPITATION SHOULD CHANGE OVER TO MAINLY RAIN FOR A TIME SOUTH
OF I-96 TUESDAY AFTERNOON AND EVENING.

WE HAVENT SEEN MUCH IMPACT FROM THE SOUTHERN STREAM OF THE JET THIS
WINTER IN MICHIGAN AND THAT LOOKS TO CHANGE VERY BRIEFLY EARLY NEXT
WEEK AS IT LIFTS NORTH IN RESPONSE TO A DEEP WEST COAST TROUGH. WIND
SPEEDS WITHIN THE UPPER JET ARE PROGGED TO BE 150 KTS OR MORE WITH
SOME POTENTIAL FOR A PERIOD OF COUPLED JET OR RIGHT ENTRANCE REGION
FORCING. THE LOW LEVEL JET IS PROGGED TO BE 50-70 KTS WHICH SENDS
PWATS OF AN INCH OR MORE NORTHWARD FROM THE GULF.

THIS LOOKS LIKE A RELATIVELY QUICK HITTING EVENT WITH MOST OF THE
PRECIP COMING IN A 12 HOUR PERIOD ON THE NOSE OF THE LOW LEVEL JET.
SUSPECT MUCH OF THIS PRECIP WILL BE CONVECTIVE IN NATURE SO HEAVY
PRECIP RATES ARE POSSIBLE BEFORE A DRY SLOT SWEEPS IN FROM THE
SOUTHWEST LATE TUESDAY/TUESDAY EVENING.

THE FREEZING RAIN/ICING POTENTIAL SHOULD BE HIGH GIVEN HOW COLD IT
HAS BEEN LATELY AND THAT ROADS/OBJECTS WILL REMAIN COLDER THAN THE
AIR TEMPS FOR THE INITIAL STAGES OF THE EVENT.

BASED ON THE LATEST THERMAL PROFILES IT LOOKS LIKE MOSTLY SNOW LATE
MONDAY NIGHT INTO EARLY TUESDAY MORNING FOLLOWED BY A QUICK CHANGE
TO FREEZING RAIN FOR AREAS NEAR/SOUTH OF I-96 15Z-21Z TUESDAY.
PRIMARILY SNOW EXPECTED NORTH OF I-96 THROUGH THE EVENT...POSSIBLY
MIXED WITH SOME SLEET/FREEZING RAIN. MAINLY RAIN SOUTH OF I-96
21Z-03Z. PRECIP GOES BACK TO ALL SNOW LATE TUESDAY NIGHT ALTHOUGH
MAINLY LIGHT WITH NO SIG ACCUMS EXPECTED.

AFTER THIS SYSTEM THE NORTHERN STREAM DOMINATES AGAIN FOR THE
REMAINDER OF THE WEEK SO MORE COLD AIR WITH OCCASIONAL LIGHT SNOW.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 650 AM EST SAT FEB 28 2015

VFR TODAY INTO THIS EVENING WITH THE EXCEPTION OF SOME MVFR CIGS
AROUND 2500 FT AT MKG THIS MORNING. LIGHT SNOW MOVING IN FROM THE
SOUTH AFTER 04Z TONIGHT WITH MVFR CIGS/VSBYS DEVELOPING. IFR VSBYS
UNDER 3 MILES MORE LIKELY LATE TONIGHT AT AZO/BTL/JXN THAN FARTHER
NORTH AT MKG/GRR/LAN.

&&

.HYDROLOGY...
ISSUED AT 1202 PM EST FRI FEB 27 2015

THE BATTLE CREEK SITE (BTCM4) ON THE KALAMAZOO RIVER HAS SHOWN
SOME ERRONEOUS DATA THROUGH THE MORNING HOURS. THIS HAS BEEN
DETERMINED TO BE CAUSED BY THE EXTREME COLD THAT SETTLED IN
OVERNIGHT. IT HAS SINCE SHOWN SIGNS OF RETURNING BACK TO ITS
ORIGINAL READING AS A RESULT OF THE SUNSHINE THIS AFTERNOON.
COORDINATION WITH LOCAL OFFICIALS HAS NOT REVEALED ANY NEED FOR
CONCERN.

WHILE AREA STREAMS AND RIVERS HAVE BEEN STABLE FOR SEVERAL WEEKS
NOW A RATHER ACTIVE PERIOD AND GRADUAL WARMING TREND IS EXPECTED.
THIS DOES NOT NECESSARILY RAISE ALARM BUT WE SHOULD HEED SPECIFICS
AS TEMPERATURES BEGIN TO INCREASE AND PRECIPITATION APPROACHES.
TOTAL PRECIPITATION THROUGH THE NEXT SEVEN DAYS IS ANTICIPATED TO
REMAIN UNDER AN INCH. THE REAL QUESTION COMES ON TUESDAY...AS TO
THE EXTENT OF WARMTH...PRECIPITATION AMOUNTS AND PRECIPITATION
TYPE. THAT SAID...WE WOULD NEED A MEANINGFUL AMOUNT OF MOISTURE
IN A SHORT PERIOD OF TIME...COUPLED WITH AN EXTENDED PERIOD OF
WARMTH TO CREATE INSTABILITY IN THE CURRENT ICE COVER. AS OF
NOW...NO REAL ISSUES ARE EXPECTED BUT RIVERS WILL BE MONITORED
THROUGH THE NEXT WEEK.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&

$$

SYNOPSIS...04
SHORT TERM...04
LONG TERM...MEADE
AVIATION...MEADE
HYDROLOGY...JAM







000
FXUS63 KGRR 281150
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
650 AM EST SAT FEB 28 2015

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 330 AM EST SAT FEB 28 2015

WEAK LOW PRESSURE WILL MOVE ACROSS SOUTHERN LOWER MICHIGAN THIS
EVENING AND SUNDAY SPREADING LIGHT SNOW AS IT MOVES EAST.
ACCUMULATIONS WILL BE LIMITED TO 1 TO PERHAPS 3 INCHES...HIGHEST
SOUTH OF I-94. A MORE SUBSTANTIAL SYSTEM WILL AFFECT LOWER MICHIGAN
MONDAY NIGHT AND TUESDAY. THE POTENTIAL EXISTS FOR MIXED FREEZING
RAIN...SLEET...AND SOME SNOW. TEMPERATURES WILL WARM INTO THE MID
30S TUESDAY BUT QUICKLY FALL INTO THE TEENS BY THURSDAY.

&&

.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 330 AM EST SAT FEB 28 2015

FORECAST CONCERNS DEAL WITH SNOW POTENTIAL TONIGHT/SUNDAY.
OVERALL...THE FORECAST DIDN/T CHANGE MUCH.

WE/LL START OFF MOSTLY SUNNY THIS MORNING BUT CLOUDS WILL BEGIN TO
SPREAD OVER THE CWA BY LATE IN THE AFTERNOON AS A COUPLE OF SHORT
WAVES MOVE IN THIS DIRECTION. BOTH OF THESE WAVES WILL MOVE JUST
SOUTH OF THE CWA BUT JET DYNAMICS WILL HELP TO PULL THE LIGHT SNOW
NORTHWARD. WE/LL SEE LIGHT SNOW DEVELOP BY 04Z SOUTH OF I-94 AND
THEN GRADUALLY SPREAD NORTHWARD TO NEAR I-96 AFTER MIDNIGHT. THIS
ISN`T AN IMPRESSIVE SYSTEM AND TOTAL SNOW SHOULD RANGE FROM AROUND
AN INCH NEAR I-96 TO PERHAPS AS HIGH AS 3 INCHES SOUTH OF I-94. SNOW
WILL END SUNDAY NIGHT AS THE SECOND WAVE MOVES EAST AND HIGH
PRESSURE WILL BUILD IN TO THE GREAT LAKES MONDAY.

.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 330 AM EST SAT FEB 28 2015

WE CONTINUE TO EXPECT A MESSY SYSTEM TO COME THROUGH ON TUESDAY WITH
A POTENTIALLY HAZARDOUS MIXTURE OF SNOW...SLEET AND FREEZING RAIN.
THE PRECIPITATION SHOULD CHANGE OVER TO MAINLY RAIN FOR A TIME SOUTH
OF I-96 TUESDAY AFTERNOON AND EVENING.

WE HAVENT SEEN MUCH IMPACT FROM THE SOUTHERN STREAM OF THE JET THIS
WINTER IN MICHIGAN AND THAT LOOKS TO CHANGE VERY BRIEFLY EARLY NEXT
WEEK AS IT LIFTS NORTH IN RESPONSE TO A DEEP WEST COAST TROUGH. WIND
SPEEDS WITHIN THE UPPER JET ARE PROGGED TO BE 150 KTS OR MORE WITH
SOME POTENTIAL FOR A PERIOD OF COUPLED JET OR RIGHT ENTRANCE REGION
FORCING. THE LOW LEVEL JET IS PROGGED TO BE 50-70 KTS WHICH SENDS
PWATS OF AN INCH OR MORE NORTHWARD FROM THE GULF.

THIS LOOKS LIKE A RELATIVELY QUICK HITTING EVENT WITH MOST OF THE
PRECIP COMING IN A 12 HOUR PERIOD ON THE NOSE OF THE LOW LEVEL JET.
SUSPECT MUCH OF THIS PRECIP WILL BE CONVECTIVE IN NATURE SO HEAVY
PRECIP RATES ARE POSSIBLE BEFORE A DRY SLOT SWEEPS IN FROM THE
SOUTHWEST LATE TUESDAY/TUESDAY EVENING.

THE FREEZING RAIN/ICING POTENTIAL SHOULD BE HIGH GIVEN HOW COLD IT
HAS BEEN LATELY AND THAT ROADS/OBJECTS WILL REMAIN COLDER THAN THE
AIR TEMPS FOR THE INITIAL STAGES OF THE EVENT.

BASED ON THE LATEST THERMAL PROFILES IT LOOKS LIKE MOSTLY SNOW LATE
MONDAY NIGHT INTO EARLY TUESDAY MORNING FOLLOWED BY A QUICK CHANGE
TO FREEZING RAIN FOR AREAS NEAR/SOUTH OF I-96 15Z-21Z TUESDAY.
PRIMARILY SNOW EXPECTED NORTH OF I-96 THROUGH THE EVENT...POSSIBLY
MIXED WITH SOME SLEET/FREEZING RAIN. MAINLY RAIN SOUTH OF I-96
21Z-03Z. PRECIP GOES BACK TO ALL SNOW LATE TUESDAY NIGHT ALTHOUGH
MAINLY LIGHT WITH NO SIG ACCUMS EXPECTED.

AFTER THIS SYSTEM THE NORTHERN STREAM DOMINATES AGAIN FOR THE
REMAINDER OF THE WEEK SO MORE COLD AIR WITH OCCASIONAL LIGHT SNOW.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 650 AM EST SAT FEB 28 2015

VFR TODAY INTO THIS EVENING WITH THE EXCEPTION OF SOME MVFR CIGS
AROUND 2500 FT AT MKG THIS MORNING. LIGHT SNOW MOVING IN FROM THE
SOUTH AFTER 04Z TONIGHT WITH MVFR CIGS/VSBYS DEVELOPING. IFR VSBYS
UNDER 3 MILES MORE LIKELY LATE TONIGHT AT AZO/BTL/JXN THAN FARTHER
NORTH AT MKG/GRR/LAN.

&&

.HYDROLOGY...
ISSUED AT 1202 PM EST FRI FEB 27 2015

THE BATTLE CREEK SITE (BTCM4) ON THE KALAMAZOO RIVER HAS SHOWN
SOME ERRONEOUS DATA THROUGH THE MORNING HOURS. THIS HAS BEEN
DETERMINED TO BE CAUSED BY THE EXTREME COLD THAT SETTLED IN
OVERNIGHT. IT HAS SINCE SHOWN SIGNS OF RETURNING BACK TO ITS
ORIGINAL READING AS A RESULT OF THE SUNSHINE THIS AFTERNOON.
COORDINATION WITH LOCAL OFFICIALS HAS NOT REVEALED ANY NEED FOR
CONCERN.

WHILE AREA STREAMS AND RIVERS HAVE BEEN STABLE FOR SEVERAL WEEKS
NOW A RATHER ACTIVE PERIOD AND GRADUAL WARMING TREND IS EXPECTED.
THIS DOES NOT NECESSARILY RAISE ALARM BUT WE SHOULD HEED SPECIFICS
AS TEMPERATURES BEGIN TO INCREASE AND PRECIPITATION APPROACHES.
TOTAL PRECIPITATION THROUGH THE NEXT SEVEN DAYS IS ANTICIPATED TO
REMAIN UNDER AN INCH. THE REAL QUESTION COMES ON TUESDAY...AS TO
THE EXTENT OF WARMTH...PRECIPITATION AMOUNTS AND PRECIPITATION
TYPE. THAT SAID...WE WOULD NEED A MEANINGFUL AMOUNT OF MOISTURE
IN A SHORT PERIOD OF TIME...COUPLED WITH AN EXTENDED PERIOD OF
WARMTH TO CREATE INSTABILITY IN THE CURRENT ICE COVER. AS OF
NOW...NO REAL ISSUES ARE EXPECTED BUT RIVERS WILL BE MONITORED
THROUGH THE NEXT WEEK.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&

$$

SYNOPSIS...04
SHORT TERM...04
LONG TERM...MEADE
AVIATION...MEADE
HYDROLOGY...JAM








000
FXUS63 KGRR 280830
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
330 AM EST SAT FEB 28 2015

LATEST UPDATE...
SYNOPSIS/SHORT TERM/LONG TERM

.SYNOPSIS...
ISSUED AT 330 AM EST SAT FEB 28 2015

WEAK LOW PRESSURE WILL MOVE ACROSS SOUTHERN LOWER MICHIGAN THIS
EVENING AND SUNDAY SPREADING LIGHT SNOW AS IT MOVES EAST.
ACCUMULATIONS WILL BE LIMITED TO 1 TO PERHAPS 3 INCHES...HIGHEST
SOUTH OF I-94. A MORE SUBSTANTIAL SYSTEM WILL AFFECT LOWER MICHIGAN
MONDAY NIGHT AND TUESDAY. THE POTENTIAL EXISTS FOR MIXED FREEZING
RAIN...SLEET...AND SOME SNOW. TEMPERATURES WILL WARM INTO THE MID
30S TUESDAY BUT QUICKLY FALL INTO THE TEENS BY THURSDAY.

&&

.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 330 AM EST SAT FEB 28 2015

FORECAST CONCERNS DEAL WITH SNOW POTENTIAL TONIGHT/SUNDAY.
OVERALL...THE FORECAST DIDN/T CHANGE MUCH.

WE/LL START OFF MOSTLY SUNNY THIS MORNING BUT CLOUDS WILL BEGIN TO
SPREAD OVER THE CWA BY LATE IN THE AFTERNOON AS A COUPLE OF SHORT
WAVES MOVE IN THIS DIRECTION. BOTH OF THESE WAVES WILL MOVE JUST
SOUTH OF THE CWA BUT JET DYNAMICS WILL HELP TO PULL THE LIGHT SNOW
NORTHWARD. WE/LL SEE LIGHT SNOW DEVELOP BY 04Z SOUTH OF I-94 AND
THEN GRADUALLY SPREAD NORTHWARD TO NEAR I-96 AFTER MIDNIGHT. THIS
ISN`T AN IMPRESSIVE SYSTEM AND TOTAL SNOW SHOULD RANGE FROM AROUND
AN INCH NEAR I-96 TO PERHAPS AS HIGH AS 3 INCHES SOUTH OF I-94. SNOW
WILL END SUNDAY NIGHT AS THE SECOND WAVE MOVES EAST AND HIGH
PRESSURE WILL BUILD IN TO THE GREAT LAKES MONDAY.

.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 330 AM EST SAT FEB 28 2015

WE CONTINUE TO EXPECT A MESSY SYSTEM TO COME THROUGH ON TUESDAY WITH
A POTENTIALLY HAZARDOUS MIXTURE OF SNOW...SLEET AND FREEZING RAIN.
THE PRECIPITATION SHOULD CHANGE OVER TO MAINLY RAIN FOR A TIME SOUTH
OF I-96 TUESDAY AFTERNOON AND EVENING.

WE HAVENT SEEN MUCH IMPACT FROM THE SOUTHERN STREAM OF THE JET THIS
WINTER IN MICHIGAN AND THAT LOOKS TO CHANGE VERY BRIEFLY EARLY NEXT
WEEK AS IT LIFTS NORTH IN RESPONSE TO A DEEP WEST COAST TROUGH. WIND
SPEEDS WITHIN THE UPPER JET ARE PROGGED TO BE 150 KTS OR MORE WITH
SOME POTENTIAL FOR A PERIOD OF COUPLED JET OR RIGHT ENTRANCE REGION
FORCING. THE LOW LEVEL JET IS PROGGED TO BE 50-70 KTS WHICH SENDS
PWATS OF AN INCH MORE NORTHWARD FROM THE GULF.

THIS LOOKS LIKE A RELATIVELY QUICK HITTING EVENT WITH MOST OF THE
PRECIP COMING IN A 12 HOUR PERIOD ON THE NOSE OF THE LOW LEVEL JET.
SUSPECT MUCH OF THIS PRECIP WILL BE CONVECTIVE IN NATURE SO HEAVY
PRECIP RATES ARE POSSIBLE BEFORE A DRY SLOT SWEEPS IN FROM THE
SOUTHWEST LATE TUESDAY/TUESDAY EVENING.

THE FREEZING RAIN/ICING POTENTIAL SHOULD BE HIGH GIVEN HOW COLD IT
HAS BEEN LATELY AND THAT ROADS/OBJECTS WILL REMAIN COLDER THAN THE
AIR TEMPS FOR THE INITIAL STAGES OF THE EVENT.

BASED ON THE LATEST THERMAL PROFILES IT LOOKS LIKE MOSTLY SNOW LATE
MONDAY NIGHT INTO EARLY TUESDAY MORNING FOLLOWED BY A QUICK CHANGE
TO FREEZING RAIN FOR AREAS NEAR/SOUTH OF I-96 15Z-21Z TUESDAY.
PRIMARILY SNOW EXPECTED NORTH OF I-96 THROUGH THE EVENT...POSSIBLY
MIXED WITH SOME SLEET/FREEZING RAIN NORTH OF I-96. MAINLY
RAIN SOUTH OF I-96 21Z-03Z. PRECIP GOES BACK TO ALL SNOW LATE
TUESDAY NIGHT ALTHOUGH MAINLY LIGHT WITH NO SIG ACCUMS EXPECTED.

AFTER THIS SYSTEM THE NORTHERN STREAM DOMINATES AGAIN FOR THE
REMAINDER OF THE WEEK SO MORE COLD AIR WITH OCCASIONAL LIGHT SNOW.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1156 PM EST FRI FEB 27 2015

VFR EXPECTED AT ALL TERMINALS EXCEPT FOR MKG AND GRR WHICH MIGHT SEE
BRIEF MVFR CIGS BEFORE 11Z. IF THESE CIGS MATERIALIZE THEY SHOULD
REMAIN ABOVE THE 3300 FT AGL FUEL ALT THRESHOLD. ANY LOW CLOUDS
SHOULD BE PUSHED NORTH OF THE AREA BY LATE MORNING AS WINDS BECOME
MORE SOUTHERLY.


&&

.HYDROLOGY...
ISSUED AT 1202 PM EST FRI FEB 27 2015

THE BATTLE CREEK SITE (BTCM4) ON THE KALAMAZOO RIVER HAS SHOWN
SOME ERRONEOUS DATA THROUGH THE MORNING HOURS. THIS HAS BEEN
DETERMINED TO BE CAUSED BY THE EXTREME COLD THAT SETTLED IN
OVERNIGHT. IT HAS SINCE SHOWN SIGNS OF RETURNING BACK TO ITS
ORIGINAL READING AS A RESULT OF THE SUNSHINE THIS AFTERNOON.
COORDINATION WITH LOCAL OFFICIALS HAS NOT REVEALED ANY NEED FOR
CONCERN.

WHILE AREA STREAMS AND RIVERS HAVE BEEN STABLE FOR SEVERAL WEEKS
NOW A RATHER ACTIVE PERIOD AND GRADUAL WARMING TREND IS EXPECTED.
THIS DOES NOT NECESSARILY RAISE ALARM BUT WE SHOULD HEED SPECIFICS
AS TEMPERATURES BEGIN TO INCREASE AND PRECIPITATION APPROACHES.
TOTAL PRECIPITATION THROUGH THE NEXT SEVEN DAYS IS ANTICIPATED TO
REMAIN UNDER AN INCH. THE REAL QUESTION COMES ON TUESDAY...AS TO
THE EXTENT OF WARMTH...PRECIPITATION AMOUNTS AND PRECIPITATION
TYPE. THAT SAID...WE WOULD NEED A MEANINGFUL AMOUNT OF MOISTURE
IN A SHORT PERIOD OF TIME...COUPLED WITH AN EXTENDED PERIOD OF
WARMTH TO CREATE INSTABILITY IN THE CURRENT ICE COVER. AS OF
NOW...NO REAL ISSUES ARE EXPECTED BUT RIVERS WILL BE MONITORED
THROUGH THE NEXT WEEK.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&

$$

SYNOPSIS...04
SHORT TERM...04
LONG TERM...MEADE
AVIATION...TJT
HYDROLOGY...JAM











000
FXUS63 KGRR 280456
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1156 PM EST FRI FEB 27 2015

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 305 PM EST FRI FEB 27 2015

THE CENTER OF A LARGE HIGH PRESSURE SYSTEM WILL PASS JUST SOUTH
OF MICHIGAN LATE TONIGHT INTO MID AFTERNOON SATURDAY. THIS WILL
BRING AND END TO THE SNOW SHOWERS OVER WESTERN AND CENTRAL
SECTIONS EARLY THIS EVENING. SKIES SHOULD BE PARTLY CLOUDY
OVERNIGHT WITH LOWS NEAR ZERO. SKIES SHOULD BECOME MOSTLY SUNNY BY
AFTERNOON SATURDAY WITH HIGHS IN THE LOWER 20S. AN UPPER LEVEL
SYSTEM PASSING OVER MICHIGAN SUNDAY WILL BRING A PERIOD OF LIGHT
SNOW TO THE AREA. ACCUMULATIONS SHOULD BE IN THE 1 TO 3 INCHES
RANGE WITH SOUTHERN AREAS SEEING THE 3 INCHES AND CENTRAL SECTIONS
NEAR I-96 SEEING THE INCH. TEMPERATURES WILL RISE TO NEAR FREEZING BY
AFTERNOON. A STORM FROM THE SOUTHERN PLAINS WILL BRING A MIX OF
SNOW... FREEZING RAIN AND RAIN TUESDAY AS TEMPERATURES RISE TO
NEAR 40

&&

.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 305 PM EST FRI FEB 27 2015

THE MAIN ISSUE WE ARE WATCHING IN THE SHORT TERM IS THE SNOWFALL
EXPECTED ON SUNDAY. OTHERWISE WE WILL SEE SLOW MODERATION TO OUR
UNUSUALLY COLD TEMPERATURES THROUGH THE WEEKEND...EACH DAY WILL BE
WARMER THAN THE PREVIOUS DAY (THROUGH SUNDAY).

THE PRIMARY DRIVER FOR THE SNOW EVENT SUNDAY IS THE A JET STREAK
FROM THE SOUTHERN STREAM THAT COMES INTO PHASE WITH THE NEXT NORTHERN
STREAM SHORTWAVE. THIS CAUSES THE SOUTHERN BRANCH JET STREAK TO
STRENGTHEN FROM AROUND 120 KNOTS SATURDAY EVENING TO NEAR 170
KNOTS AS IT PASSES SOUTH OF LAKE ERIE SUNDAY NIGHT. THAT SORT OF
STRENGTHENING CAUSES STRONG FGEN WHICH SLOPES NORTHWARD FROM NEAR
700 MB NEAR FWA TO NEAR 400 MB OVER HTL AS THE JET STREAK MOVES
THROUGH. OF COURSE THAT SORT DYNAMIC DEMANDS A LOW TO MID LEVEL
RESPONSE WHICH IS TO LIFT AIR NORTHWARD TOWARD MICHIGAN AS THIS
JET FEATURE MOVES THROUGH. SO...THE KEY TO WHERE THE HEAVY SNOW
FALLS REALLY IS JUST WHERE THE AXIS OF THE JET STREAK IS. SINCE
THE JET STREAK AXIS IS JUST SOUTH OF MICHIGAN THAT IS WHERE THE
HEAVIEST SNOW IS LIKELY TO FALL. STILL THERE IS MID LEVEL LIFT
OVER LOWER MICHIGAN SO WE WILL SEE SOME LIGHT SNOW FROM THIS
EVENT. I AM THINKING AROUND AN INCH NEAR GRR TO 2 TO 3 INCHES JUST
SOUTH OF INTERSTATE 94. COLD AIR FOLLOWING THE JET STREAK WILL
LEAD TO A SHALLOW LAKE EFFECT SNOW SHOWER EVENT SUNDAY NIGHT BUT
THIS WILL BE NOT MUCH MORE THAN FLURRIES SINCE INVERSION HEIGHTS
WILL BE BELOW 5000 FT.

OTHERWISE THE LAKE EFFECT SNOW BAND MOVING ONSHORE TODAY WILL
DISSIPATE BY EARLY THIS EVENING LEAVING PARTLY CLOUDY SKIES
TONIGHT. THE CLOUDS IN FROM THE SOUTHWEST WINDS OFF LAKE MICHIGAN
WILL KEEP THE TEMPERATURES FROM FALLING LIKE LAST NIGHT SO LOWS
WILL BE MILDER.

SATURDAY SHOULD SEE SOME CLEARING BY MID AFTERNOON AS WINDS BECOME
MORE SOUTHERLY AND NOT OFF LAKE MICHIGAN ANYMORE. SATURDAY NIGHT
WILL SEE INCREASING MID AND HIGH CLOUDS AS THE SYSTEM SNOW HEADS
THIS WAY.

.LONG TERM...(MONDAY THROUGH FRIDAY)
ISSUED AT 305 PM EST FRI FEB 27 2015

MAIN FOCUS OF THE FCST CONTINUES TO BE THE SYSTEM EXPECTED TO COME
THROUGH DURING THE MON NIGHT THROUGH TUE NIGHT TIME FRAME. THERE ARE
ONLY MINOR CHANGES TO THE THINKING WITH REGARDS TO THIS SYSTEM.
THOSE CHANGES ARE MAINLY THE RESULT OF THE EXACT TRACK OF THE LOW.

WE CONTINUE TO EXPECT PCPN TO DEVELOP AS SNOW LATE MON NIGHT...AFTER
A QUIET PERIOD ON MON WITH HIGH PRESSURE OVERHEAD. PCPN IS EXPECTED
TO START OUT AS SNOW ACROSS THE ENTIRE CWFA OVERNIGHT MON NIGHT INTO
EARLY TUE MORNING. THERE IS FAIRLY GOOD MODEL CONSENSUS THAT TEMPS
ALOFT WILL WARM ABOVE FREEZING BY TUE AFTERNOON...ALLOWING P-TYPES
TO CHANGE OVER TO SOME SLEET AND/OR FREEZING RAIN FOR MOST OF THE
AREA. THIS WILL LIKELY BE BRIEF WHERE TEMPS COME ABOVE FREEZING TUE
AFTERNOON AND EVENING...WHICH IS CURRENTLY EXPECTED TO OCCUR ALONG
AND SOUTH OF I-96.

AREAS NORTH OF I-96 COULD END UP REMAINING ALL SNOW/SLEET/FREEZING
RAIN NORTH OF THE LOW TRACK WHERE TEMPS COULD POTENTIALLY STAY BELOW
FREEZING THE ENTIRE TIME. THIS COULD BE WHERE A DECENT AMOUNT OF
ICING COULD TAKE PLACE.

WE CAN EXPECT FLUCTUATIONS IN THE TRACK OF THE LOW AND PLACEMENT OF
P-TYPES FOR AT LEAST ANOTHER 24 TO 48 HOURS. THIS IS DUE TO THE FACT
THAT THE ENERGY THAT WILL AFFECT THIS SYSTEM IS STILL WELL OVER THE
BERING SEA...WEST OF ALASKA. ONCE IT MOVES OVER THE CONTINENT AND
INTO THE RAOB NETWORK...BETTER SAMPLING SHOULD TAKE PLACE. THE OTHER
MAIN PART OF THIS...THE LOW OVER THE PACIFIC NW...IS ALREADY
STARTING TO BE SAMPLED BETTER.

WE SHOULD SEE A QUICK BURST OF ARCTIC AIR FOLLOW THIS SYSTEM COMING
IN ON WED AND HOLDING INTO THU. SOME LAKE EFFECT WILL BE POSSIBLE AT
THAT TIME. A QUICK MODERATION COMES LATE NEXT WEEK AS THE NRN BRANCH
OF THE JET LIFTS BACK NORTH OF THE AREA. WE WILL SEE A WRLY FLOW
OVER THE AREA WITH THE NEXT CLIPPER SYSTEM POTENTIALLY STAYING NORTH
OF THE BORDER.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1156 PM EST FRI FEB 27 2015

VFR EXPECTED AT ALL TERMINALS EXCEPT FOR MKG AND GRR WHICH MIGHT SEE
BRIEF MVFR CIGS BEFORE 11Z. IF THESE CIGS MATERIALIZE THEY SHOULD
REMAIN ABOVE THE 2000 FT AGL FUEL ALT THRESHOLD. ANY LOW CLOUDS
SHOULD BE PUSHED NORTH OF THE AREA BY LATE MORNING AS WINDS BECOME
MORE SOUTHERLY.

&&

.HYDROLOGY...
ISSUED AT 1202 PM EST FRI FEB 27 2015

THE BATTLE CREEK SITE (BTCM4) ON THE KALAMAZOO RIVER HAS SHOWN
SOME ERRONEOUS DATA THROUGH THE MORNING HOURS. THIS HAS BEEN
DETERMINED TO BE CAUSED BY THE EXTREME COLD THAT SETTLED IN
OVERNIGHT. IT HAS SINCE SHOWN SIGNS OF RETURNING BACK TO ITS
ORIGINAL READING AS A RESULT OF THE SUNSHINE THIS AFTERNOON.
COORDINATION WITH LOCAL OFFICIALS HAS NOT REVEALED ANY NEED FOR
CONCERN.

WHILE AREA STREAMS AND RIVERS HAVE BEEN STABLE FOR SEVERAL WEEKS
NOW A RATHER ACTIVE PERIOD AND GRADUAL WARMING TREND IS EXPECTED.
THIS DOES NOT NECESSARILY RAISE ALARM BUT WE SHOULD HEED SPECIFICS
AS TEMPERATURES BEGIN TO INCREASE AND PRECIPITATION APPROACHES.
TOTAL PRECIPITATION THROUGH THE NEXT SEVEN DAYS IS ANTICIPATED TO
REMAIN UNDER AN INCH. THE REAL QUESTION COMES ON TUESDAY...AS TO
THE EXTENT OF WARMTH...PRECIPITATION AMOUNTS AND PRECIPITATION
TYPE. THAT SAID...WE WOULD NEED A MEANINGFUL AMOUNT OF MOISTURE
IN A SHORT PERIOD OF TIME...COUPLED WITH AN EXTENDED PERIOD OF
WARMTH TO CREATE INSTABILITY IN THE CURRENT ICE COVER. AS OF
NOW...NO REAL ISSUES ARE EXPECTED BUT RIVERS WILL BE MONITORED
THROUGH THE NEXT WEEK.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&

$$

SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...NJJ
AVIATION...TJT
HYDROLOGY...JAM








000
FXUS63 KGRR 280456
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1156 PM EST FRI FEB 27 2015

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 305 PM EST FRI FEB 27 2015

THE CENTER OF A LARGE HIGH PRESSURE SYSTEM WILL PASS JUST SOUTH
OF MICHIGAN LATE TONIGHT INTO MID AFTERNOON SATURDAY. THIS WILL
BRING AND END TO THE SNOW SHOWERS OVER WESTERN AND CENTRAL
SECTIONS EARLY THIS EVENING. SKIES SHOULD BE PARTLY CLOUDY
OVERNIGHT WITH LOWS NEAR ZERO. SKIES SHOULD BECOME MOSTLY SUNNY BY
AFTERNOON SATURDAY WITH HIGHS IN THE LOWER 20S. AN UPPER LEVEL
SYSTEM PASSING OVER MICHIGAN SUNDAY WILL BRING A PERIOD OF LIGHT
SNOW TO THE AREA. ACCUMULATIONS SHOULD BE IN THE 1 TO 3 INCHES
RANGE WITH SOUTHERN AREAS SEEING THE 3 INCHES AND CENTRAL SECTIONS
NEAR I-96 SEEING THE INCH. TEMPERATURES WILL RISE TO NEAR FREEZING BY
AFTERNOON. A STORM FROM THE SOUTHERN PLAINS WILL BRING A MIX OF
SNOW... FREEZING RAIN AND RAIN TUESDAY AS TEMPERATURES RISE TO
NEAR 40

&&

.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 305 PM EST FRI FEB 27 2015

THE MAIN ISSUE WE ARE WATCHING IN THE SHORT TERM IS THE SNOWFALL
EXPECTED ON SUNDAY. OTHERWISE WE WILL SEE SLOW MODERATION TO OUR
UNUSUALLY COLD TEMPERATURES THROUGH THE WEEKEND...EACH DAY WILL BE
WARMER THAN THE PREVIOUS DAY (THROUGH SUNDAY).

THE PRIMARY DRIVER FOR THE SNOW EVENT SUNDAY IS THE A JET STREAK
FROM THE SOUTHERN STREAM THAT COMES INTO PHASE WITH THE NEXT NORTHERN
STREAM SHORTWAVE. THIS CAUSES THE SOUTHERN BRANCH JET STREAK TO
STRENGTHEN FROM AROUND 120 KNOTS SATURDAY EVENING TO NEAR 170
KNOTS AS IT PASSES SOUTH OF LAKE ERIE SUNDAY NIGHT. THAT SORT OF
STRENGTHENING CAUSES STRONG FGEN WHICH SLOPES NORTHWARD FROM NEAR
700 MB NEAR FWA TO NEAR 400 MB OVER HTL AS THE JET STREAK MOVES
THROUGH. OF COURSE THAT SORT DYNAMIC DEMANDS A LOW TO MID LEVEL
RESPONSE WHICH IS TO LIFT AIR NORTHWARD TOWARD MICHIGAN AS THIS
JET FEATURE MOVES THROUGH. SO...THE KEY TO WHERE THE HEAVY SNOW
FALLS REALLY IS JUST WHERE THE AXIS OF THE JET STREAK IS. SINCE
THE JET STREAK AXIS IS JUST SOUTH OF MICHIGAN THAT IS WHERE THE
HEAVIEST SNOW IS LIKELY TO FALL. STILL THERE IS MID LEVEL LIFT
OVER LOWER MICHIGAN SO WE WILL SEE SOME LIGHT SNOW FROM THIS
EVENT. I AM THINKING AROUND AN INCH NEAR GRR TO 2 TO 3 INCHES JUST
SOUTH OF INTERSTATE 94. COLD AIR FOLLOWING THE JET STREAK WILL
LEAD TO A SHALLOW LAKE EFFECT SNOW SHOWER EVENT SUNDAY NIGHT BUT
THIS WILL BE NOT MUCH MORE THAN FLURRIES SINCE INVERSION HEIGHTS
WILL BE BELOW 5000 FT.

OTHERWISE THE LAKE EFFECT SNOW BAND MOVING ONSHORE TODAY WILL
DISSIPATE BY EARLY THIS EVENING LEAVING PARTLY CLOUDY SKIES
TONIGHT. THE CLOUDS IN FROM THE SOUTHWEST WINDS OFF LAKE MICHIGAN
WILL KEEP THE TEMPERATURES FROM FALLING LIKE LAST NIGHT SO LOWS
WILL BE MILDER.

SATURDAY SHOULD SEE SOME CLEARING BY MID AFTERNOON AS WINDS BECOME
MORE SOUTHERLY AND NOT OFF LAKE MICHIGAN ANYMORE. SATURDAY NIGHT
WILL SEE INCREASING MID AND HIGH CLOUDS AS THE SYSTEM SNOW HEADS
THIS WAY.

.LONG TERM...(MONDAY THROUGH FRIDAY)
ISSUED AT 305 PM EST FRI FEB 27 2015

MAIN FOCUS OF THE FCST CONTINUES TO BE THE SYSTEM EXPECTED TO COME
THROUGH DURING THE MON NIGHT THROUGH TUE NIGHT TIME FRAME. THERE ARE
ONLY MINOR CHANGES TO THE THINKING WITH REGARDS TO THIS SYSTEM.
THOSE CHANGES ARE MAINLY THE RESULT OF THE EXACT TRACK OF THE LOW.

WE CONTINUE TO EXPECT PCPN TO DEVELOP AS SNOW LATE MON NIGHT...AFTER
A QUIET PERIOD ON MON WITH HIGH PRESSURE OVERHEAD. PCPN IS EXPECTED
TO START OUT AS SNOW ACROSS THE ENTIRE CWFA OVERNIGHT MON NIGHT INTO
EARLY TUE MORNING. THERE IS FAIRLY GOOD MODEL CONSENSUS THAT TEMPS
ALOFT WILL WARM ABOVE FREEZING BY TUE AFTERNOON...ALLOWING P-TYPES
TO CHANGE OVER TO SOME SLEET AND/OR FREEZING RAIN FOR MOST OF THE
AREA. THIS WILL LIKELY BE BRIEF WHERE TEMPS COME ABOVE FREEZING TUE
AFTERNOON AND EVENING...WHICH IS CURRENTLY EXPECTED TO OCCUR ALONG
AND SOUTH OF I-96.

AREAS NORTH OF I-96 COULD END UP REMAINING ALL SNOW/SLEET/FREEZING
RAIN NORTH OF THE LOW TRACK WHERE TEMPS COULD POTENTIALLY STAY BELOW
FREEZING THE ENTIRE TIME. THIS COULD BE WHERE A DECENT AMOUNT OF
ICING COULD TAKE PLACE.

WE CAN EXPECT FLUCTUATIONS IN THE TRACK OF THE LOW AND PLACEMENT OF
P-TYPES FOR AT LEAST ANOTHER 24 TO 48 HOURS. THIS IS DUE TO THE FACT
THAT THE ENERGY THAT WILL AFFECT THIS SYSTEM IS STILL WELL OVER THE
BERING SEA...WEST OF ALASKA. ONCE IT MOVES OVER THE CONTINENT AND
INTO THE RAOB NETWORK...BETTER SAMPLING SHOULD TAKE PLACE. THE OTHER
MAIN PART OF THIS...THE LOW OVER THE PACIFIC NW...IS ALREADY
STARTING TO BE SAMPLED BETTER.

WE SHOULD SEE A QUICK BURST OF ARCTIC AIR FOLLOW THIS SYSTEM COMING
IN ON WED AND HOLDING INTO THU. SOME LAKE EFFECT WILL BE POSSIBLE AT
THAT TIME. A QUICK MODERATION COMES LATE NEXT WEEK AS THE NRN BRANCH
OF THE JET LIFTS BACK NORTH OF THE AREA. WE WILL SEE A WRLY FLOW
OVER THE AREA WITH THE NEXT CLIPPER SYSTEM POTENTIALLY STAYING NORTH
OF THE BORDER.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1156 PM EST FRI FEB 27 2015

VFR EXPECTED AT ALL TERMINALS EXCEPT FOR MKG AND GRR WHICH MIGHT SEE
BRIEF MVFR CIGS BEFORE 11Z. IF THESE CIGS MATERIALIZE THEY SHOULD
REMAIN ABOVE THE 2000 FT AGL FUEL ALT THRESHOLD. ANY LOW CLOUDS
SHOULD BE PUSHED NORTH OF THE AREA BY LATE MORNING AS WINDS BECOME
MORE SOUTHERLY.

&&

.HYDROLOGY...
ISSUED AT 1202 PM EST FRI FEB 27 2015

THE BATTLE CREEK SITE (BTCM4) ON THE KALAMAZOO RIVER HAS SHOWN
SOME ERRONEOUS DATA THROUGH THE MORNING HOURS. THIS HAS BEEN
DETERMINED TO BE CAUSED BY THE EXTREME COLD THAT SETTLED IN
OVERNIGHT. IT HAS SINCE SHOWN SIGNS OF RETURNING BACK TO ITS
ORIGINAL READING AS A RESULT OF THE SUNSHINE THIS AFTERNOON.
COORDINATION WITH LOCAL OFFICIALS HAS NOT REVEALED ANY NEED FOR
CONCERN.

WHILE AREA STREAMS AND RIVERS HAVE BEEN STABLE FOR SEVERAL WEEKS
NOW A RATHER ACTIVE PERIOD AND GRADUAL WARMING TREND IS EXPECTED.
THIS DOES NOT NECESSARILY RAISE ALARM BUT WE SHOULD HEED SPECIFICS
AS TEMPERATURES BEGIN TO INCREASE AND PRECIPITATION APPROACHES.
TOTAL PRECIPITATION THROUGH THE NEXT SEVEN DAYS IS ANTICIPATED TO
REMAIN UNDER AN INCH. THE REAL QUESTION COMES ON TUESDAY...AS TO
THE EXTENT OF WARMTH...PRECIPITATION AMOUNTS AND PRECIPITATION
TYPE. THAT SAID...WE WOULD NEED A MEANINGFUL AMOUNT OF MOISTURE
IN A SHORT PERIOD OF TIME...COUPLED WITH AN EXTENDED PERIOD OF
WARMTH TO CREATE INSTABILITY IN THE CURRENT ICE COVER. AS OF
NOW...NO REAL ISSUES ARE EXPECTED BUT RIVERS WILL BE MONITORED
THROUGH THE NEXT WEEK.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&

$$

SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...NJJ
AVIATION...TJT
HYDROLOGY...JAM







000
FXUS63 KGRR 280456
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1156 PM EST FRI FEB 27 2015

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 305 PM EST FRI FEB 27 2015

THE CENTER OF A LARGE HIGH PRESSURE SYSTEM WILL PASS JUST SOUTH
OF MICHIGAN LATE TONIGHT INTO MID AFTERNOON SATURDAY. THIS WILL
BRING AND END TO THE SNOW SHOWERS OVER WESTERN AND CENTRAL
SECTIONS EARLY THIS EVENING. SKIES SHOULD BE PARTLY CLOUDY
OVERNIGHT WITH LOWS NEAR ZERO. SKIES SHOULD BECOME MOSTLY SUNNY BY
AFTERNOON SATURDAY WITH HIGHS IN THE LOWER 20S. AN UPPER LEVEL
SYSTEM PASSING OVER MICHIGAN SUNDAY WILL BRING A PERIOD OF LIGHT
SNOW TO THE AREA. ACCUMULATIONS SHOULD BE IN THE 1 TO 3 INCHES
RANGE WITH SOUTHERN AREAS SEEING THE 3 INCHES AND CENTRAL SECTIONS
NEAR I-96 SEEING THE INCH. TEMPERATURES WILL RISE TO NEAR FREEZING BY
AFTERNOON. A STORM FROM THE SOUTHERN PLAINS WILL BRING A MIX OF
SNOW... FREEZING RAIN AND RAIN TUESDAY AS TEMPERATURES RISE TO
NEAR 40

&&

.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 305 PM EST FRI FEB 27 2015

THE MAIN ISSUE WE ARE WATCHING IN THE SHORT TERM IS THE SNOWFALL
EXPECTED ON SUNDAY. OTHERWISE WE WILL SEE SLOW MODERATION TO OUR
UNUSUALLY COLD TEMPERATURES THROUGH THE WEEKEND...EACH DAY WILL BE
WARMER THAN THE PREVIOUS DAY (THROUGH SUNDAY).

THE PRIMARY DRIVER FOR THE SNOW EVENT SUNDAY IS THE A JET STREAK
FROM THE SOUTHERN STREAM THAT COMES INTO PHASE WITH THE NEXT NORTHERN
STREAM SHORTWAVE. THIS CAUSES THE SOUTHERN BRANCH JET STREAK TO
STRENGTHEN FROM AROUND 120 KNOTS SATURDAY EVENING TO NEAR 170
KNOTS AS IT PASSES SOUTH OF LAKE ERIE SUNDAY NIGHT. THAT SORT OF
STRENGTHENING CAUSES STRONG FGEN WHICH SLOPES NORTHWARD FROM NEAR
700 MB NEAR FWA TO NEAR 400 MB OVER HTL AS THE JET STREAK MOVES
THROUGH. OF COURSE THAT SORT DYNAMIC DEMANDS A LOW TO MID LEVEL
RESPONSE WHICH IS TO LIFT AIR NORTHWARD TOWARD MICHIGAN AS THIS
JET FEATURE MOVES THROUGH. SO...THE KEY TO WHERE THE HEAVY SNOW
FALLS REALLY IS JUST WHERE THE AXIS OF THE JET STREAK IS. SINCE
THE JET STREAK AXIS IS JUST SOUTH OF MICHIGAN THAT IS WHERE THE
HEAVIEST SNOW IS LIKELY TO FALL. STILL THERE IS MID LEVEL LIFT
OVER LOWER MICHIGAN SO WE WILL SEE SOME LIGHT SNOW FROM THIS
EVENT. I AM THINKING AROUND AN INCH NEAR GRR TO 2 TO 3 INCHES JUST
SOUTH OF INTERSTATE 94. COLD AIR FOLLOWING THE JET STREAK WILL
LEAD TO A SHALLOW LAKE EFFECT SNOW SHOWER EVENT SUNDAY NIGHT BUT
THIS WILL BE NOT MUCH MORE THAN FLURRIES SINCE INVERSION HEIGHTS
WILL BE BELOW 5000 FT.

OTHERWISE THE LAKE EFFECT SNOW BAND MOVING ONSHORE TODAY WILL
DISSIPATE BY EARLY THIS EVENING LEAVING PARTLY CLOUDY SKIES
TONIGHT. THE CLOUDS IN FROM THE SOUTHWEST WINDS OFF LAKE MICHIGAN
WILL KEEP THE TEMPERATURES FROM FALLING LIKE LAST NIGHT SO LOWS
WILL BE MILDER.

SATURDAY SHOULD SEE SOME CLEARING BY MID AFTERNOON AS WINDS BECOME
MORE SOUTHERLY AND NOT OFF LAKE MICHIGAN ANYMORE. SATURDAY NIGHT
WILL SEE INCREASING MID AND HIGH CLOUDS AS THE SYSTEM SNOW HEADS
THIS WAY.

.LONG TERM...(MONDAY THROUGH FRIDAY)
ISSUED AT 305 PM EST FRI FEB 27 2015

MAIN FOCUS OF THE FCST CONTINUES TO BE THE SYSTEM EXPECTED TO COME
THROUGH DURING THE MON NIGHT THROUGH TUE NIGHT TIME FRAME. THERE ARE
ONLY MINOR CHANGES TO THE THINKING WITH REGARDS TO THIS SYSTEM.
THOSE CHANGES ARE MAINLY THE RESULT OF THE EXACT TRACK OF THE LOW.

WE CONTINUE TO EXPECT PCPN TO DEVELOP AS SNOW LATE MON NIGHT...AFTER
A QUIET PERIOD ON MON WITH HIGH PRESSURE OVERHEAD. PCPN IS EXPECTED
TO START OUT AS SNOW ACROSS THE ENTIRE CWFA OVERNIGHT MON NIGHT INTO
EARLY TUE MORNING. THERE IS FAIRLY GOOD MODEL CONSENSUS THAT TEMPS
ALOFT WILL WARM ABOVE FREEZING BY TUE AFTERNOON...ALLOWING P-TYPES
TO CHANGE OVER TO SOME SLEET AND/OR FREEZING RAIN FOR MOST OF THE
AREA. THIS WILL LIKELY BE BRIEF WHERE TEMPS COME ABOVE FREEZING TUE
AFTERNOON AND EVENING...WHICH IS CURRENTLY EXPECTED TO OCCUR ALONG
AND SOUTH OF I-96.

AREAS NORTH OF I-96 COULD END UP REMAINING ALL SNOW/SLEET/FREEZING
RAIN NORTH OF THE LOW TRACK WHERE TEMPS COULD POTENTIALLY STAY BELOW
FREEZING THE ENTIRE TIME. THIS COULD BE WHERE A DECENT AMOUNT OF
ICING COULD TAKE PLACE.

WE CAN EXPECT FLUCTUATIONS IN THE TRACK OF THE LOW AND PLACEMENT OF
P-TYPES FOR AT LEAST ANOTHER 24 TO 48 HOURS. THIS IS DUE TO THE FACT
THAT THE ENERGY THAT WILL AFFECT THIS SYSTEM IS STILL WELL OVER THE
BERING SEA...WEST OF ALASKA. ONCE IT MOVES OVER THE CONTINENT AND
INTO THE RAOB NETWORK...BETTER SAMPLING SHOULD TAKE PLACE. THE OTHER
MAIN PART OF THIS...THE LOW OVER THE PACIFIC NW...IS ALREADY
STARTING TO BE SAMPLED BETTER.

WE SHOULD SEE A QUICK BURST OF ARCTIC AIR FOLLOW THIS SYSTEM COMING
IN ON WED AND HOLDING INTO THU. SOME LAKE EFFECT WILL BE POSSIBLE AT
THAT TIME. A QUICK MODERATION COMES LATE NEXT WEEK AS THE NRN BRANCH
OF THE JET LIFTS BACK NORTH OF THE AREA. WE WILL SEE A WRLY FLOW
OVER THE AREA WITH THE NEXT CLIPPER SYSTEM POTENTIALLY STAYING NORTH
OF THE BORDER.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1156 PM EST FRI FEB 27 2015

VFR EXPECTED AT ALL TERMINALS EXCEPT FOR MKG AND GRR WHICH MIGHT SEE
BRIEF MVFR CIGS BEFORE 11Z. IF THESE CIGS MATERIALIZE THEY SHOULD
REMAIN ABOVE THE 2000 FT AGL FUEL ALT THRESHOLD. ANY LOW CLOUDS
SHOULD BE PUSHED NORTH OF THE AREA BY LATE MORNING AS WINDS BECOME
MORE SOUTHERLY.

&&

.HYDROLOGY...
ISSUED AT 1202 PM EST FRI FEB 27 2015

THE BATTLE CREEK SITE (BTCM4) ON THE KALAMAZOO RIVER HAS SHOWN
SOME ERRONEOUS DATA THROUGH THE MORNING HOURS. THIS HAS BEEN
DETERMINED TO BE CAUSED BY THE EXTREME COLD THAT SETTLED IN
OVERNIGHT. IT HAS SINCE SHOWN SIGNS OF RETURNING BACK TO ITS
ORIGINAL READING AS A RESULT OF THE SUNSHINE THIS AFTERNOON.
COORDINATION WITH LOCAL OFFICIALS HAS NOT REVEALED ANY NEED FOR
CONCERN.

WHILE AREA STREAMS AND RIVERS HAVE BEEN STABLE FOR SEVERAL WEEKS
NOW A RATHER ACTIVE PERIOD AND GRADUAL WARMING TREND IS EXPECTED.
THIS DOES NOT NECESSARILY RAISE ALARM BUT WE SHOULD HEED SPECIFICS
AS TEMPERATURES BEGIN TO INCREASE AND PRECIPITATION APPROACHES.
TOTAL PRECIPITATION THROUGH THE NEXT SEVEN DAYS IS ANTICIPATED TO
REMAIN UNDER AN INCH. THE REAL QUESTION COMES ON TUESDAY...AS TO
THE EXTENT OF WARMTH...PRECIPITATION AMOUNTS AND PRECIPITATION
TYPE. THAT SAID...WE WOULD NEED A MEANINGFUL AMOUNT OF MOISTURE
IN A SHORT PERIOD OF TIME...COUPLED WITH AN EXTENDED PERIOD OF
WARMTH TO CREATE INSTABILITY IN THE CURRENT ICE COVER. AS OF
NOW...NO REAL ISSUES ARE EXPECTED BUT RIVERS WILL BE MONITORED
THROUGH THE NEXT WEEK.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&

$$

SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...NJJ
AVIATION...TJT
HYDROLOGY...JAM








000
FXUS63 KGRR 280456
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1156 PM EST FRI FEB 27 2015

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 305 PM EST FRI FEB 27 2015

THE CENTER OF A LARGE HIGH PRESSURE SYSTEM WILL PASS JUST SOUTH
OF MICHIGAN LATE TONIGHT INTO MID AFTERNOON SATURDAY. THIS WILL
BRING AND END TO THE SNOW SHOWERS OVER WESTERN AND CENTRAL
SECTIONS EARLY THIS EVENING. SKIES SHOULD BE PARTLY CLOUDY
OVERNIGHT WITH LOWS NEAR ZERO. SKIES SHOULD BECOME MOSTLY SUNNY BY
AFTERNOON SATURDAY WITH HIGHS IN THE LOWER 20S. AN UPPER LEVEL
SYSTEM PASSING OVER MICHIGAN SUNDAY WILL BRING A PERIOD OF LIGHT
SNOW TO THE AREA. ACCUMULATIONS SHOULD BE IN THE 1 TO 3 INCHES
RANGE WITH SOUTHERN AREAS SEEING THE 3 INCHES AND CENTRAL SECTIONS
NEAR I-96 SEEING THE INCH. TEMPERATURES WILL RISE TO NEAR FREEZING BY
AFTERNOON. A STORM FROM THE SOUTHERN PLAINS WILL BRING A MIX OF
SNOW... FREEZING RAIN AND RAIN TUESDAY AS TEMPERATURES RISE TO
NEAR 40

&&

.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 305 PM EST FRI FEB 27 2015

THE MAIN ISSUE WE ARE WATCHING IN THE SHORT TERM IS THE SNOWFALL
EXPECTED ON SUNDAY. OTHERWISE WE WILL SEE SLOW MODERATION TO OUR
UNUSUALLY COLD TEMPERATURES THROUGH THE WEEKEND...EACH DAY WILL BE
WARMER THAN THE PREVIOUS DAY (THROUGH SUNDAY).

THE PRIMARY DRIVER FOR THE SNOW EVENT SUNDAY IS THE A JET STREAK
FROM THE SOUTHERN STREAM THAT COMES INTO PHASE WITH THE NEXT NORTHERN
STREAM SHORTWAVE. THIS CAUSES THE SOUTHERN BRANCH JET STREAK TO
STRENGTHEN FROM AROUND 120 KNOTS SATURDAY EVENING TO NEAR 170
KNOTS AS IT PASSES SOUTH OF LAKE ERIE SUNDAY NIGHT. THAT SORT OF
STRENGTHENING CAUSES STRONG FGEN WHICH SLOPES NORTHWARD FROM NEAR
700 MB NEAR FWA TO NEAR 400 MB OVER HTL AS THE JET STREAK MOVES
THROUGH. OF COURSE THAT SORT DYNAMIC DEMANDS A LOW TO MID LEVEL
RESPONSE WHICH IS TO LIFT AIR NORTHWARD TOWARD MICHIGAN AS THIS
JET FEATURE MOVES THROUGH. SO...THE KEY TO WHERE THE HEAVY SNOW
FALLS REALLY IS JUST WHERE THE AXIS OF THE JET STREAK IS. SINCE
THE JET STREAK AXIS IS JUST SOUTH OF MICHIGAN THAT IS WHERE THE
HEAVIEST SNOW IS LIKELY TO FALL. STILL THERE IS MID LEVEL LIFT
OVER LOWER MICHIGAN SO WE WILL SEE SOME LIGHT SNOW FROM THIS
EVENT. I AM THINKING AROUND AN INCH NEAR GRR TO 2 TO 3 INCHES JUST
SOUTH OF INTERSTATE 94. COLD AIR FOLLOWING THE JET STREAK WILL
LEAD TO A SHALLOW LAKE EFFECT SNOW SHOWER EVENT SUNDAY NIGHT BUT
THIS WILL BE NOT MUCH MORE THAN FLURRIES SINCE INVERSION HEIGHTS
WILL BE BELOW 5000 FT.

OTHERWISE THE LAKE EFFECT SNOW BAND MOVING ONSHORE TODAY WILL
DISSIPATE BY EARLY THIS EVENING LEAVING PARTLY CLOUDY SKIES
TONIGHT. THE CLOUDS IN FROM THE SOUTHWEST WINDS OFF LAKE MICHIGAN
WILL KEEP THE TEMPERATURES FROM FALLING LIKE LAST NIGHT SO LOWS
WILL BE MILDER.

SATURDAY SHOULD SEE SOME CLEARING BY MID AFTERNOON AS WINDS BECOME
MORE SOUTHERLY AND NOT OFF LAKE MICHIGAN ANYMORE. SATURDAY NIGHT
WILL SEE INCREASING MID AND HIGH CLOUDS AS THE SYSTEM SNOW HEADS
THIS WAY.

.LONG TERM...(MONDAY THROUGH FRIDAY)
ISSUED AT 305 PM EST FRI FEB 27 2015

MAIN FOCUS OF THE FCST CONTINUES TO BE THE SYSTEM EXPECTED TO COME
THROUGH DURING THE MON NIGHT THROUGH TUE NIGHT TIME FRAME. THERE ARE
ONLY MINOR CHANGES TO THE THINKING WITH REGARDS TO THIS SYSTEM.
THOSE CHANGES ARE MAINLY THE RESULT OF THE EXACT TRACK OF THE LOW.

WE CONTINUE TO EXPECT PCPN TO DEVELOP AS SNOW LATE MON NIGHT...AFTER
A QUIET PERIOD ON MON WITH HIGH PRESSURE OVERHEAD. PCPN IS EXPECTED
TO START OUT AS SNOW ACROSS THE ENTIRE CWFA OVERNIGHT MON NIGHT INTO
EARLY TUE MORNING. THERE IS FAIRLY GOOD MODEL CONSENSUS THAT TEMPS
ALOFT WILL WARM ABOVE FREEZING BY TUE AFTERNOON...ALLOWING P-TYPES
TO CHANGE OVER TO SOME SLEET AND/OR FREEZING RAIN FOR MOST OF THE
AREA. THIS WILL LIKELY BE BRIEF WHERE TEMPS COME ABOVE FREEZING TUE
AFTERNOON AND EVENING...WHICH IS CURRENTLY EXPECTED TO OCCUR ALONG
AND SOUTH OF I-96.

AREAS NORTH OF I-96 COULD END UP REMAINING ALL SNOW/SLEET/FREEZING
RAIN NORTH OF THE LOW TRACK WHERE TEMPS COULD POTENTIALLY STAY BELOW
FREEZING THE ENTIRE TIME. THIS COULD BE WHERE A DECENT AMOUNT OF
ICING COULD TAKE PLACE.

WE CAN EXPECT FLUCTUATIONS IN THE TRACK OF THE LOW AND PLACEMENT OF
P-TYPES FOR AT LEAST ANOTHER 24 TO 48 HOURS. THIS IS DUE TO THE FACT
THAT THE ENERGY THAT WILL AFFECT THIS SYSTEM IS STILL WELL OVER THE
BERING SEA...WEST OF ALASKA. ONCE IT MOVES OVER THE CONTINENT AND
INTO THE RAOB NETWORK...BETTER SAMPLING SHOULD TAKE PLACE. THE OTHER
MAIN PART OF THIS...THE LOW OVER THE PACIFIC NW...IS ALREADY
STARTING TO BE SAMPLED BETTER.

WE SHOULD SEE A QUICK BURST OF ARCTIC AIR FOLLOW THIS SYSTEM COMING
IN ON WED AND HOLDING INTO THU. SOME LAKE EFFECT WILL BE POSSIBLE AT
THAT TIME. A QUICK MODERATION COMES LATE NEXT WEEK AS THE NRN BRANCH
OF THE JET LIFTS BACK NORTH OF THE AREA. WE WILL SEE A WRLY FLOW
OVER THE AREA WITH THE NEXT CLIPPER SYSTEM POTENTIALLY STAYING NORTH
OF THE BORDER.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1156 PM EST FRI FEB 27 2015

VFR EXPECTED AT ALL TERMINALS EXCEPT FOR MKG AND GRR WHICH MIGHT SEE
BRIEF MVFR CIGS BEFORE 11Z. IF THESE CIGS MATERIALIZE THEY SHOULD
REMAIN ABOVE THE 2000 FT AGL FUEL ALT THRESHOLD. ANY LOW CLOUDS
SHOULD BE PUSHED NORTH OF THE AREA BY LATE MORNING AS WINDS BECOME
MORE SOUTHERLY.

&&

.HYDROLOGY...
ISSUED AT 1202 PM EST FRI FEB 27 2015

THE BATTLE CREEK SITE (BTCM4) ON THE KALAMAZOO RIVER HAS SHOWN
SOME ERRONEOUS DATA THROUGH THE MORNING HOURS. THIS HAS BEEN
DETERMINED TO BE CAUSED BY THE EXTREME COLD THAT SETTLED IN
OVERNIGHT. IT HAS SINCE SHOWN SIGNS OF RETURNING BACK TO ITS
ORIGINAL READING AS A RESULT OF THE SUNSHINE THIS AFTERNOON.
COORDINATION WITH LOCAL OFFICIALS HAS NOT REVEALED ANY NEED FOR
CONCERN.

WHILE AREA STREAMS AND RIVERS HAVE BEEN STABLE FOR SEVERAL WEEKS
NOW A RATHER ACTIVE PERIOD AND GRADUAL WARMING TREND IS EXPECTED.
THIS DOES NOT NECESSARILY RAISE ALARM BUT WE SHOULD HEED SPECIFICS
AS TEMPERATURES BEGIN TO INCREASE AND PRECIPITATION APPROACHES.
TOTAL PRECIPITATION THROUGH THE NEXT SEVEN DAYS IS ANTICIPATED TO
REMAIN UNDER AN INCH. THE REAL QUESTION COMES ON TUESDAY...AS TO
THE EXTENT OF WARMTH...PRECIPITATION AMOUNTS AND PRECIPITATION
TYPE. THAT SAID...WE WOULD NEED A MEANINGFUL AMOUNT OF MOISTURE
IN A SHORT PERIOD OF TIME...COUPLED WITH AN EXTENDED PERIOD OF
WARMTH TO CREATE INSTABILITY IN THE CURRENT ICE COVER. AS OF
NOW...NO REAL ISSUES ARE EXPECTED BUT RIVERS WILL BE MONITORED
THROUGH THE NEXT WEEK.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&

$$

SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...NJJ
AVIATION...TJT
HYDROLOGY...JAM







000
FXUS63 KGRR 280007
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
707 PM EST FRI FEB 27 2015

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 305 PM EST FRI FEB 27 2015

THE CENTER OF A LARGE HIGH PRESSURE SYSTEM WILL PASS JUST SOUTH
OF MICHIGAN LATE TONIGHT INTO MID AFTERNOON SATURDAY. THIS WILL
BRING AND END TO THE SNOW SHOWERS OVER WESTERN AND CENTRAL
SECTIONS EARLY THIS EVENING. SKIES SHOULD BE PARTLY CLOUDY
OVERNIGHT WITH LOWS NEAR ZERO. SKIES SHOULD BECOME MOSTLY SUNNY BY
AFTERNOON SATURDAY WITH HIGHS IN THE LOWER 20S. AN UPPER LEVEL
SYSTEM PASSING OVER MICHIGAN SUNDAY WILL BRING A PERIOD OF LIGHT
SNOW TO THE AREA. ACCUMULATIONS SHOULD BE IN THE 1 TO 3 INCHES
RANGE WITH SOUTHERN AREAS SEEING THE 3 INCHES AND CENTRAL SECTIONS
NEAR I-96 SEEING THE INCH. TEMPERATURES WILL RISE TO NEAR FREEZING BY
AFTERNOON. A STORM FROM THE SOUTHERN PLAINS WILL BRING A MIX OF
SNOW... FREEZING RAIN AND RAIN TUESDAY AS TEMPERATURES RISE TO
NEAR 40

&&

.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 305 PM EST FRI FEB 27 2015

THE MAIN ISSUE WE ARE WATCHING IN THE SHORT TERM IS THE SNOWFALL
EXPECTED ON SUNDAY. OTHERWISE WE WILL SEE SLOW MODERATION TO OUR
UNUSUALLY COLD TEMPERATURES THROUGH THE WEEKEND...EACH DAY WILL BE
WARMER THAN THE PREVIOUS DAY (THROUGH SUNDAY).

THE PRIMARY DRIVER FOR THE SNOW EVENT SUNDAY IS THE A JET STREAK
FROM THE SOUTHERN STREAM THAT COMES INTO PHASE WITH THE NEXT NORTHERN
STREAM SHORTWAVE. THIS CAUSES THE SOUTHERN BRANCH JET STREAK TO
STRENGTHEN FROM AROUND 120 KNOTS SATURDAY EVENING TO NEAR 170
KNOTS AS IT PASSES SOUTH OF LAKE ERIE SUNDAY NIGHT. THAT SORT OF
STRENGTHENING CAUSES STRONG FGEN WHICH SLOPES NORTHWARD FROM NEAR
700 MB NEAR FWA TO NEAR 400 MB OVER HTL AS THE JET STREAK MOVES
THROUGH. OF COURSE THAT SORT DYNAMIC DEMANDS A LOW TO MID LEVEL
RESPONSE WHICH IS TO LIFT AIR NORTHWARD TOWARD MICHIGAN AS THIS
JET FEATURE MOVES THROUGH. SO...THE KEY TO WHERE THE HEAVY SNOW
FALLS REALLY IS JUST WHERE THE AXIS OF THE JET STREAK IS. SINCE
THE JET STREAK AXIS IS JUST SOUTH OF MICHIGAN THAT IS WHERE THE
HEAVIEST SNOW IS LIKELY TO FALL. STILL THERE IS MID LEVEL LIFT
OVER LOWER MICHIGAN SO WE WILL SEE SOME LIGHT SNOW FROM THIS
EVENT. I AM THINKING AROUND AN INCH NEAR GRR TO 2 TO 3 INCHES JUST
SOUTH OF INTERSTATE 94. COLD AIR FOLLOWING THE JET STREAK WILL
LEAD TO A SHALLOW LAKE EFFECT SNOW SHOWER EVENT SUNDAY NIGHT BUT
THIS WILL BE NOT MUCH MORE THAN FLURRIES SINCE INVERSION HEIGHTS
WILL BE BELOW 5000 FT.

OTHERWISE THE LAKE EFFECT SNOW BAND MOVING ONSHORE TODAY WILL
DISSIPATE BY EARLY THIS EVENING LEAVING PARTLY CLOUDY SKIES
TONIGHT. THE CLOUDS IN FROM THE SOUTHWEST WINDS OFF LAKE MICHIGAN
WILL KEEP THE TEMPERATURES FROM FALLING LIKE LAST NIGHT SO LOWS
WILL BE MILDER.

SATURDAY SHOULD SEE SOME CLEARING BY MID AFTERNOON AS WINDS BECOME
MORE SOUTHERLY AND NOT OFF LAKE MICHIGAN ANYMORE. SATURDAY NIGHT
WILL SEE INCREASING MID AND HIGH CLOUDS AS THE SYSTEM SNOW HEADS
THIS WAY.

.LONG TERM...(MONDAY THROUGH FRIDAY)
ISSUED AT 305 PM EST FRI FEB 27 2015

MAIN FOCUS OF THE FCST CONTINUES TO BE THE SYSTEM EXPECTED TO COME
THROUGH DURING THE MON NIGHT THROUGH TUE NIGHT TIME FRAME. THERE ARE
ONLY MINOR CHANGES TO THE THINKING WITH REGARDS TO THIS SYSTEM.
THOSE CHANGES ARE MAINLY THE RESULT OF THE EXACT TRACK OF THE LOW.

WE CONTINUE TO EXPECT PCPN TO DEVELOP AS SNOW LATE MON NIGHT...AFTER
A QUIET PERIOD ON MON WITH HIGH PRESSURE OVERHEAD. PCPN IS EXPECTED
TO START OUT AS SNOW ACROSS THE ENTIRE CWFA OVERNIGHT MON NIGHT INTO
EARLY TUE MORNING. THERE IS FAIRLY GOOD MODEL CONSENSUS THAT TEMPS
ALOFT WILL WARM ABOVE FREEZING BY TUE AFTERNOON...ALLOWING P-TYPES
TO CHANGE OVER TO SOME SLEET AND/OR FREEZING RAIN FOR MOST OF THE
AREA. THIS WILL LIKELY BE BRIEF WHERE TEMPS COME ABOVE FREEZING TUE
AFTERNOON AND EVENING...WHICH IS CURRENTLY EXPECTED TO OCCUR ALONG
AND SOUTH OF I-96.

AREAS NORTH OF I-96 COULD END UP REMAINING ALL SNOW/SLEET/FREEZING
RAIN NORTH OF THE LOW TRACK WHERE TEMPS COULD POTENTIALLY STAY BELOW
FREEZING THE ENTIRE TIME. THIS COULD BE WHERE A DECENT AMOUNT OF
ICING COULD TAKE PLACE.

WE CAN EXPECT FLUCTUATIONS IN THE TRACK OF THE LOW AND PLACEMENT OF
P-TYPES FOR AT LEAST ANOTHER 24 TO 48 HOURS. THIS IS DUE TO THE FACT
THAT THE ENERGY THAT WILL AFFECT THIS SYSTEM IS STILL WELL OVER THE
BERING SEA...WEST OF ALASKA. ONCE IT MOVES OVER THE CONTINENT AND
INTO THE RAOB NETWORK...BETTER SAMPLING SHOULD TAKE PLACE. THE OTHER
MAIN PART OF THIS...THE LOW OVER THE PACIFIC NW...IS ALREADY
STARTING TO BE SAMPLED BETTER.

WE SHOULD SEE A QUICK BURST OF ARCTIC AIR FOLLOW THIS SYSTEM COMING
IN ON WED AND HOLDING INTO THU. SOME LAKE EFFECT WILL BE POSSIBLE AT
THAT TIME. A QUICK MODERATION COMES LATE NEXT WEEK AS THE NRN BRANCH
OF THE JET LIFTS BACK NORTH OF THE AREA. WE WILL SEE A WRLY FLOW
OVER THE AREA WITH THE NEXT CLIPPER SYSTEM POTENTIALLY STAYING NORTH
OF THE BORDER.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 705 PM EST FRI FEB 27 2015

NO CHANGES TO PREVIOUS THINKING. THERE IS A SLIGHT CHANCE FOR
MVFR CIGS TO DEVELOP AT SOME OF THE TERMINALS LATER TONIGHT...BUT
ANY CIGS THAT DEVELOP SHOULD REMAIN 2500 FT AGL OR HIGHER...AND
THEREFORE ABOVE FUEL ALTERNATE THRESHOLDS.

&&

.HYDROLOGY...
ISSUED AT 1202 PM EST FRI FEB 27 2015

THE BATTLE CREEK SITE (BTCM4) ON THE KALAMAZOO RIVER HAS SHOWN
SOME ERRONEOUS DATA THROUGH THE MORNING HOURS. THIS HAS BEEN
DETERMINED TO BE CAUSED BY THE EXTREME COLD THAT SETTLED IN
OVERNIGHT. IT HAS SINCE SHOWN SIGNS OF RETURNING BACK TO ITS
ORIGINAL READING AS A RESULT OF THE SUNSHINE THIS AFTERNOON.
COORDINATION WITH LOCAL OFFICIALS HAS NOT REVEALED ANY NEED FOR
CONCERN.

WHILE AREA STREAMS AND RIVERS HAVE BEEN STABLE FOR SEVERAL WEEKS
NOW A RATHER ACTIVE PERIOD AND GRADUAL WARMING TREND IS EXPECTED.
THIS DOES NOT NECESSARILY RAISE ALARM BUT WE SHOULD HEED SPECIFICS
AS TEMPERATURES BEGIN TO INCREASE AND PRECIPITATION APPROACHES.
TOTAL PRECIPITATION THROUGH THE NEXT SEVEN DAYS IS ANTICIPATED TO
REMAIN UNDER AN INCH. THE REAL QUESTION COMES ON TUESDAY...AS TO
THE EXTENT OF WARMTH...PRECIPITATION AMOUNTS AND PRECIPITATION
TYPE. THAT SAID...WE WOULD NEED A MEANINGFUL AMOUNT OF MOISTURE
IN A SHORT PERIOD OF TIME...COUPLED WITH AN EXTENDED PERIOD OF
WARMTH TO CREATE INSTABILITY IN THE CURRENT ICE COVER. AS OF
NOW...NO REAL ISSUES ARE EXPECTED BUT RIVERS WILL BE MONITORED
THROUGH THE NEXT WEEK.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&

$$

SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...NJJ
AVIATION...TJT
HYDROLOGY...JAM







000
FXUS63 KGRR 280007
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
707 PM EST FRI FEB 27 2015

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 305 PM EST FRI FEB 27 2015

THE CENTER OF A LARGE HIGH PRESSURE SYSTEM WILL PASS JUST SOUTH
OF MICHIGAN LATE TONIGHT INTO MID AFTERNOON SATURDAY. THIS WILL
BRING AND END TO THE SNOW SHOWERS OVER WESTERN AND CENTRAL
SECTIONS EARLY THIS EVENING. SKIES SHOULD BE PARTLY CLOUDY
OVERNIGHT WITH LOWS NEAR ZERO. SKIES SHOULD BECOME MOSTLY SUNNY BY
AFTERNOON SATURDAY WITH HIGHS IN THE LOWER 20S. AN UPPER LEVEL
SYSTEM PASSING OVER MICHIGAN SUNDAY WILL BRING A PERIOD OF LIGHT
SNOW TO THE AREA. ACCUMULATIONS SHOULD BE IN THE 1 TO 3 INCHES
RANGE WITH SOUTHERN AREAS SEEING THE 3 INCHES AND CENTRAL SECTIONS
NEAR I-96 SEEING THE INCH. TEMPERATURES WILL RISE TO NEAR FREEZING BY
AFTERNOON. A STORM FROM THE SOUTHERN PLAINS WILL BRING A MIX OF
SNOW... FREEZING RAIN AND RAIN TUESDAY AS TEMPERATURES RISE TO
NEAR 40

&&

.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 305 PM EST FRI FEB 27 2015

THE MAIN ISSUE WE ARE WATCHING IN THE SHORT TERM IS THE SNOWFALL
EXPECTED ON SUNDAY. OTHERWISE WE WILL SEE SLOW MODERATION TO OUR
UNUSUALLY COLD TEMPERATURES THROUGH THE WEEKEND...EACH DAY WILL BE
WARMER THAN THE PREVIOUS DAY (THROUGH SUNDAY).

THE PRIMARY DRIVER FOR THE SNOW EVENT SUNDAY IS THE A JET STREAK
FROM THE SOUTHERN STREAM THAT COMES INTO PHASE WITH THE NEXT NORTHERN
STREAM SHORTWAVE. THIS CAUSES THE SOUTHERN BRANCH JET STREAK TO
STRENGTHEN FROM AROUND 120 KNOTS SATURDAY EVENING TO NEAR 170
KNOTS AS IT PASSES SOUTH OF LAKE ERIE SUNDAY NIGHT. THAT SORT OF
STRENGTHENING CAUSES STRONG FGEN WHICH SLOPES NORTHWARD FROM NEAR
700 MB NEAR FWA TO NEAR 400 MB OVER HTL AS THE JET STREAK MOVES
THROUGH. OF COURSE THAT SORT DYNAMIC DEMANDS A LOW TO MID LEVEL
RESPONSE WHICH IS TO LIFT AIR NORTHWARD TOWARD MICHIGAN AS THIS
JET FEATURE MOVES THROUGH. SO...THE KEY TO WHERE THE HEAVY SNOW
FALLS REALLY IS JUST WHERE THE AXIS OF THE JET STREAK IS. SINCE
THE JET STREAK AXIS IS JUST SOUTH OF MICHIGAN THAT IS WHERE THE
HEAVIEST SNOW IS LIKELY TO FALL. STILL THERE IS MID LEVEL LIFT
OVER LOWER MICHIGAN SO WE WILL SEE SOME LIGHT SNOW FROM THIS
EVENT. I AM THINKING AROUND AN INCH NEAR GRR TO 2 TO 3 INCHES JUST
SOUTH OF INTERSTATE 94. COLD AIR FOLLOWING THE JET STREAK WILL
LEAD TO A SHALLOW LAKE EFFECT SNOW SHOWER EVENT SUNDAY NIGHT BUT
THIS WILL BE NOT MUCH MORE THAN FLURRIES SINCE INVERSION HEIGHTS
WILL BE BELOW 5000 FT.

OTHERWISE THE LAKE EFFECT SNOW BAND MOVING ONSHORE TODAY WILL
DISSIPATE BY EARLY THIS EVENING LEAVING PARTLY CLOUDY SKIES
TONIGHT. THE CLOUDS IN FROM THE SOUTHWEST WINDS OFF LAKE MICHIGAN
WILL KEEP THE TEMPERATURES FROM FALLING LIKE LAST NIGHT SO LOWS
WILL BE MILDER.

SATURDAY SHOULD SEE SOME CLEARING BY MID AFTERNOON AS WINDS BECOME
MORE SOUTHERLY AND NOT OFF LAKE MICHIGAN ANYMORE. SATURDAY NIGHT
WILL SEE INCREASING MID AND HIGH CLOUDS AS THE SYSTEM SNOW HEADS
THIS WAY.

.LONG TERM...(MONDAY THROUGH FRIDAY)
ISSUED AT 305 PM EST FRI FEB 27 2015

MAIN FOCUS OF THE FCST CONTINUES TO BE THE SYSTEM EXPECTED TO COME
THROUGH DURING THE MON NIGHT THROUGH TUE NIGHT TIME FRAME. THERE ARE
ONLY MINOR CHANGES TO THE THINKING WITH REGARDS TO THIS SYSTEM.
THOSE CHANGES ARE MAINLY THE RESULT OF THE EXACT TRACK OF THE LOW.

WE CONTINUE TO EXPECT PCPN TO DEVELOP AS SNOW LATE MON NIGHT...AFTER
A QUIET PERIOD ON MON WITH HIGH PRESSURE OVERHEAD. PCPN IS EXPECTED
TO START OUT AS SNOW ACROSS THE ENTIRE CWFA OVERNIGHT MON NIGHT INTO
EARLY TUE MORNING. THERE IS FAIRLY GOOD MODEL CONSENSUS THAT TEMPS
ALOFT WILL WARM ABOVE FREEZING BY TUE AFTERNOON...ALLOWING P-TYPES
TO CHANGE OVER TO SOME SLEET AND/OR FREEZING RAIN FOR MOST OF THE
AREA. THIS WILL LIKELY BE BRIEF WHERE TEMPS COME ABOVE FREEZING TUE
AFTERNOON AND EVENING...WHICH IS CURRENTLY EXPECTED TO OCCUR ALONG
AND SOUTH OF I-96.

AREAS NORTH OF I-96 COULD END UP REMAINING ALL SNOW/SLEET/FREEZING
RAIN NORTH OF THE LOW TRACK WHERE TEMPS COULD POTENTIALLY STAY BELOW
FREEZING THE ENTIRE TIME. THIS COULD BE WHERE A DECENT AMOUNT OF
ICING COULD TAKE PLACE.

WE CAN EXPECT FLUCTUATIONS IN THE TRACK OF THE LOW AND PLACEMENT OF
P-TYPES FOR AT LEAST ANOTHER 24 TO 48 HOURS. THIS IS DUE TO THE FACT
THAT THE ENERGY THAT WILL AFFECT THIS SYSTEM IS STILL WELL OVER THE
BERING SEA...WEST OF ALASKA. ONCE IT MOVES OVER THE CONTINENT AND
INTO THE RAOB NETWORK...BETTER SAMPLING SHOULD TAKE PLACE. THE OTHER
MAIN PART OF THIS...THE LOW OVER THE PACIFIC NW...IS ALREADY
STARTING TO BE SAMPLED BETTER.

WE SHOULD SEE A QUICK BURST OF ARCTIC AIR FOLLOW THIS SYSTEM COMING
IN ON WED AND HOLDING INTO THU. SOME LAKE EFFECT WILL BE POSSIBLE AT
THAT TIME. A QUICK MODERATION COMES LATE NEXT WEEK AS THE NRN BRANCH
OF THE JET LIFTS BACK NORTH OF THE AREA. WE WILL SEE A WRLY FLOW
OVER THE AREA WITH THE NEXT CLIPPER SYSTEM POTENTIALLY STAYING NORTH
OF THE BORDER.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 705 PM EST FRI FEB 27 2015

NO CHANGES TO PREVIOUS THINKING. THERE IS A SLIGHT CHANCE FOR
MVFR CIGS TO DEVELOP AT SOME OF THE TERMINALS LATER TONIGHT...BUT
ANY CIGS THAT DEVELOP SHOULD REMAIN 2500 FT AGL OR HIGHER...AND
THEREFORE ABOVE FUEL ALTERNATE THRESHOLDS.

&&

.HYDROLOGY...
ISSUED AT 1202 PM EST FRI FEB 27 2015

THE BATTLE CREEK SITE (BTCM4) ON THE KALAMAZOO RIVER HAS SHOWN
SOME ERRONEOUS DATA THROUGH THE MORNING HOURS. THIS HAS BEEN
DETERMINED TO BE CAUSED BY THE EXTREME COLD THAT SETTLED IN
OVERNIGHT. IT HAS SINCE SHOWN SIGNS OF RETURNING BACK TO ITS
ORIGINAL READING AS A RESULT OF THE SUNSHINE THIS AFTERNOON.
COORDINATION WITH LOCAL OFFICIALS HAS NOT REVEALED ANY NEED FOR
CONCERN.

WHILE AREA STREAMS AND RIVERS HAVE BEEN STABLE FOR SEVERAL WEEKS
NOW A RATHER ACTIVE PERIOD AND GRADUAL WARMING TREND IS EXPECTED.
THIS DOES NOT NECESSARILY RAISE ALARM BUT WE SHOULD HEED SPECIFICS
AS TEMPERATURES BEGIN TO INCREASE AND PRECIPITATION APPROACHES.
TOTAL PRECIPITATION THROUGH THE NEXT SEVEN DAYS IS ANTICIPATED TO
REMAIN UNDER AN INCH. THE REAL QUESTION COMES ON TUESDAY...AS TO
THE EXTENT OF WARMTH...PRECIPITATION AMOUNTS AND PRECIPITATION
TYPE. THAT SAID...WE WOULD NEED A MEANINGFUL AMOUNT OF MOISTURE
IN A SHORT PERIOD OF TIME...COUPLED WITH AN EXTENDED PERIOD OF
WARMTH TO CREATE INSTABILITY IN THE CURRENT ICE COVER. AS OF
NOW...NO REAL ISSUES ARE EXPECTED BUT RIVERS WILL BE MONITORED
THROUGH THE NEXT WEEK.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&

$$

SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...NJJ
AVIATION...TJT
HYDROLOGY...JAM








000
FXUS63 KGRR 272011
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
311 PM EST FRI FEB 27 2015

LATEST UPDATE...
SYNOPSIS/SHORT TERM/LONG TERM

.SYNOPSIS...
ISSUED AT 305 PM EST FRI FEB 27 2015

THE CENTER OF A LARGE HIGH PRESSURE SYSTEM WILL PASS JUST SOUTH
OF MICHIGAN LATE TONIGHT INTO MID AFTERNOON SATURDAY. THIS WILL
BRING AND END TO THE SNOW SHOWERS OVER WESTERN AND CENTRAL
SECTIONS EARLY THIS EVENING. SKIES SHOULD BE PARTLY CLOUDY
OVERNIGHT WITH LOWS NEAR ZERO. SKIES SHOULD BECOME MOSTLY SUNNY BY
AFTERNOON SATURDAY WITH HIGHS IN THE LOWER 20S. AN UPPER LEVEL
SYSTEM PASSING OVER MICHIGAN SUNDAY WILL BRING A PERIOD OF LIGHT
SNOW TO THE AREA. ACCUMULATIONS SHOULD BE IN THE 1 TO 3 INCHES
RANGE WITH SOUTHERN AREAS SEEING THE 3 INCHES AND CENTRAL SECTIONS
NEAR I-96 SEEING THE INCH. TEMPERATURES WILL RISE TO NEAR FREEZING BY
AFTERNOON. A STORM FROM THE SOUTHERN PLAINS WILL BRING A MIX OF
SNOW... FREEZING RAIN AND RAIN TUESDAY AS TEMPERATURES RISE TO
NEAR 40


&&

.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 305 PM EST FRI FEB 27 2015

THE MAIN ISSUE WE ARE WATCHING IN THE SHORT TERM IS THE SNOWFALL
EXPECTED ON SUNDAY. OTHERWISE WE WILL SEE SLOW MODERATION TO OUR
UNUSUALLY COLD TEMPERATURES THROUGH THE WEEKEND...EACH DAY WILL BE
WARMER THAN THE PREVIOUS DAY (THROUGH SUNDAY).

THE PRIMARY DRIVER FOR THE SNOW EVENT SUNDAY IS THE A JET STREAK
FROM THE SOUTHERN STREAM THAT COMES INTO PHASE WITH THE NEXT NORTHERN
STREAM SHORTWAVE. THIS CAUSES THE SOUTHERN BRANCH JET STREAK TO
STRENGTHEN FROM AROUND 120 KNOTS SATURDAY EVENING TO NEAR 170
KNOTS AS IT PASSES SOUTH OF LAKE ERIE SUNDAY NIGHT. THAT SORT OF
STRENGTHENING CAUSES STRONG FGEN WHICH SLOPES NORTHWARD FROM NEAR
700 MB NEAR FWA TO NEAR 400 MB OVER HTL AS THE JET STREAK MOVES
THROUGH. OF COURSE THAT SORT DYNAMIC DEMANDS A LOW TO MID LEVEL
RESPONSE WHICH IS TO LIFT AIR NORTHWARD TOWARD MICHIGAN AS THIS
JET FEATURE MOVES THROUGH. SO...THE KEY TO WHERE THE HEAVY SNOW
FALLS REALLY IS JUST WHERE THE AXIS OF THE JET STREAK IS. SINCE
THE JET STREAK ASIX IS JUST SOUTH OF MICHIGAN THAT IS WHERE THE
HEAVIEST SNOW IS LIKELY TO FALL. STILL THERE IS MID LEVEL LIFT
OVER LOWER MICHIGAN SO WE WILL SEE SOME LIGHT SNOW FROM THIS
EVENT. I AM THINKING AROUND AN INCH NEAR GRR TO 2 TO 3 INCHES JUST
SOUTH OF INTERSTATE 94. COLD AIR FOLLOWING THE JET STREAK WILL
LEAD TO A SHALLOW LAKE EFFECT SNOW SHOWER EVENT SUNDAY NIGHT BUT
THIS WILL BE NOT MUCH MORE THAN FLURRIES SINCE INVERSION HEIGHTS
WILL BE BELOW 5000 FT.

OTHERWISE THE LAKE EFFECT SNOW BAND MOVING ONSHORE TODAY WILL
DISSIPATE BY EARLY THIS EVENING LEAVING PARTLY CLOUDY SKIES
TONIGHT. THE CLOUDS IN FROM THE SOUTHWEST WINDS OFF LAKE MICHIGAN
WILL KEEP THE TEMPERATURES FROM FALLING LIKE LAST NIGHT SO LOWS
WILL BE MILDER.

SATURDAY SHOULD SEE SOME CLEARING BY MID AFTERNOON AS WINDS BECOME
MORE SOUTHERLY AND NOT OFF LAKE MICHIGAN ANYMORE. SATURDAY NIGHT
WILL SEE INCREASING MID AND HIGH CLOUDS AS THE SYSTEM SNOW HEADS
THIS WAY.


.LONG TERM...(MONDAY THROUGH FRIDAY)
ISSUED AT 305 PM EST FRI FEB 27 2015

MAIN FOCUS OF THE FCST CONTINUES TO BE THE SYSTEM EXPECTED TO COME
THROUGH DURING THE MON NIGHT THROUGH TUE NIGHT TIME FRAME. THERE ARE
ONLY MINOR CHANGES TO THE THINKING WITH REGARDS TO THIS SYSTEM.
THOSE CHANGES ARE MAINLY THE RESULT OF THE EXACT TRACK OF THE LOW.

WE CONTINUE TO EXPECT PCPN TO DEVELOP AS SNOW LATE MON NIGHT...AFTER
A QUIET PERIOD ON MON WITH HIGH PRESSURE OVERHEAD. PCPN IS EXPECTED
TO START OUT AS SNOW ACROSS THE ENTIRE CWFA OVERNIGHT MON NIGHT INTO
EARLY TUE MORNING. THERE IS FAIRLY GOOD MODEL CONSENSUS THAT TEMPS
ALOFT WILL WARM ABOVE FREEZING BY TUE AFTERNOON...ALLOWING P-TYPES
TO CHANGE OVER TO SOME SLEET AND/OR FREEZING RAIN FOR MOST OF THE
AREA. THIS WILL LIKELY BE BRIEF WHERE TEMPS COME ABOVE FREEZING TUE
AFTERNOON AND EVENING...WHICH IS CURRENTLY EXPECTED TO OCCUR ALONG
AND SOUTH OF I-96.

AREAS NORTH OF I-96 COULD END UP REMAINING ALL SNOW/SLEET/FREEZING
RAIN NORTH OF THE LOW TRACK WHERE TEMPS COULD POTENTIALLY STAY BELOW
FREEZING THE ENTIRE TIME. THIS COULD BE WHERE A DECENT AMOUNT OF
ICING COULD TAKE PLACE.

WE CAN EXPECT FLUCTUATIONS IN THE TRACK OF THE LOW AND PLACEMENT OF
P-TYPES FOR AT LEAST ANOTHER 24 TO 48 HOURS. THIS IS DUE TO THE FACT
THAT THE ENERGY THAT WILL AFFECT THIS SYSTEM IS STILL WELL OVER THE
BERING SEA...WEST OF ALASKA. ONCE IT MOVES OVER THE CONTINENT AND
INTO THE RAOB NETWORK...BETTER SAMPLING SHOULD TAKE PLACE. THE OTHER
MAIN PART OF THIS...THE LOW OVER THE PACIFIC NW...IS ALREADY
STARTING TO BE SAMPLED BETTER.

WE SHOULD SEE A QUICK BURST OF ARCTIC AIR FOLLOW THIS SYSTEM COMING
IN ON WED AND HOLDING INTO THU. SOME LAKE EFFECT WILL BE POSSIBLE AT
THAT TIME. A QUICK MODERATION COMES LATE NEXT WEEK AS THE NRN BRANCH
OF THE JET LIFTS BACK NORTH OF THE AREA. WE WILL SEE A WRLY FLOW
OVER THE AREA WITH THE NEXT CLIPPER SYSTEM POTENTIALLY STAYING NORTH
OF THE BORDER.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1237 PM EST FRI FEB 27 2015

MAIN IMPACT TO AVIATION OPERATIONS WILL BE LAKE EFFECT CLOUDS AND
SOME SNOW SHOWERS MOVING INLAND THIS AFTERNOON. THE CLOUD LEVEL
WINDS ARE SHIFTING ONSHORE THIS AFTERNOON...WHICH IS HELPING TO
PUSH LAKE EFFECT INLAND. SOME IFR WAS REPORTED AT KMKG
EARLIER...WHICH HAS SINCE MOVED INLAND. WE EXPECT THAT THE SNOW
SHOWERS WILL WEAKEN THIS AFTERNOON AS THE MAIN BAND MOVING ONSHORE
DISPERSES. KGRR COULD SEE A FEW OF THESE...BUT WE EXPECT MAINLY
MVFR WITH ANY SNOW SHOWERS. SOME BRIEF AND ISOLATED IFR WILL BE
POSSIBLE.

LAKE EFFECT WILL CLEAR OUT OF THE AREA ACROSS THE SRN TERMINALS
THIS EVENING AS THE FLOW BECOMES SW IN THE CLOUD LAYER. KMKG AND
KGRR WILL HOLD ON TO THE VFR DECK INTO SAT MORNING BEFORE IT
EVENTUALLY MOVES NORTH/DISSIPATES. CAN NOT RULE OUT SOME OF THE
CIGS GOING MVFR OVERNIGHT.


&&

.HYDROLOGY...
ISSUED AT 1202 PM EST FRI FEB 27 2015

THE BATTLE CREEK SITE (BTCM4) ON THE KALAMAZOO RIVER HAS SHOWN
SOME ERRONEOUS DATA THROUGH THE MORNING HOURS. THIS HAS BEEN
DETERMINED TO BE CAUSED BY THE EXTREME COLD THAT SETTLED IN
OVERNIGHT. IT HAS SINCE SHOWN SIGNS OF RETURNING BACK TO ITS
ORIGINAL READING AS A RESULT OF THE SUNSHINE THIS AFTERNOON.
COORDINATION WITH LOCAL OFFICIALS HAS NOT REVEALED ANY NEED FOR
CONCERN.

WHILE AREA STREAMS AND RIVERS HAVE BEEN STABLE FOR SEVERAL WEEKS
NOW A RATHER ACTIVE PERIOD AND GRADUAL WARMING TREND IS EXPECTED.
THIS DOES NOT NECESSARILY RAISE ALARM BUT WE SHOULD HEED SPECIFICS
AS TEMPERATURES BEGIN TO INCREASE AND PRECIPITATION APPROACHES.
TOTAL PRECIPITATION THROUGH THE NEXT SEVEN DAYS IS ANTICIPATED TO
REMAIN UNDER AN INCH. THE REAL QUESTION COMES ON TUESDAY...AS TO
THE EXTENT OF WARMTH...PRECIPITATION AMOUNTS AND PRECIPITATION
TYPE. THAT SAID...WE WOULD NEED A MEANINGFUL AMOUNT OF MOISTURE
IN A SHORT PERIOD OF TIME...COUPLED WITH AN EXTENDED PERIOD OF
WARMTH TO CREATE INSTABILITY IN THE CURRENT ICE COVER. AS OF
NOW...NO REAL ISSUES ARE EXPECTED BUT RIVERS WILL BE MONITORED
THROUGH THE NEXT WEEK.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&

$$

SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...NJJ
AVIATION...NJJ
HYDROLOGY...JAM








000
FXUS63 KGRR 272011
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
311 PM EST FRI FEB 27 2015

LATEST UPDATE...
SYNOPSIS/SHORT TERM/LONG TERM

.SYNOPSIS...
ISSUED AT 305 PM EST FRI FEB 27 2015

THE CENTER OF A LARGE HIGH PRESSURE SYSTEM WILL PASS JUST SOUTH
OF MICHIGAN LATE TONIGHT INTO MID AFTERNOON SATURDAY. THIS WILL
BRING AND END TO THE SNOW SHOWERS OVER WESTERN AND CENTRAL
SECTIONS EARLY THIS EVENING. SKIES SHOULD BE PARTLY CLOUDY
OVERNIGHT WITH LOWS NEAR ZERO. SKIES SHOULD BECOME MOSTLY SUNNY BY
AFTERNOON SATURDAY WITH HIGHS IN THE LOWER 20S. AN UPPER LEVEL
SYSTEM PASSING OVER MICHIGAN SUNDAY WILL BRING A PERIOD OF LIGHT
SNOW TO THE AREA. ACCUMULATIONS SHOULD BE IN THE 1 TO 3 INCHES
RANGE WITH SOUTHERN AREAS SEEING THE 3 INCHES AND CENTRAL SECTIONS
NEAR I-96 SEEING THE INCH. TEMPERATURES WILL RISE TO NEAR FREEZING BY
AFTERNOON. A STORM FROM THE SOUTHERN PLAINS WILL BRING A MIX OF
SNOW... FREEZING RAIN AND RAIN TUESDAY AS TEMPERATURES RISE TO
NEAR 40


&&

.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 305 PM EST FRI FEB 27 2015

THE MAIN ISSUE WE ARE WATCHING IN THE SHORT TERM IS THE SNOWFALL
EXPECTED ON SUNDAY. OTHERWISE WE WILL SEE SLOW MODERATION TO OUR
UNUSUALLY COLD TEMPERATURES THROUGH THE WEEKEND...EACH DAY WILL BE
WARMER THAN THE PREVIOUS DAY (THROUGH SUNDAY).

THE PRIMARY DRIVER FOR THE SNOW EVENT SUNDAY IS THE A JET STREAK
FROM THE SOUTHERN STREAM THAT COMES INTO PHASE WITH THE NEXT NORTHERN
STREAM SHORTWAVE. THIS CAUSES THE SOUTHERN BRANCH JET STREAK TO
STRENGTHEN FROM AROUND 120 KNOTS SATURDAY EVENING TO NEAR 170
KNOTS AS IT PASSES SOUTH OF LAKE ERIE SUNDAY NIGHT. THAT SORT OF
STRENGTHENING CAUSES STRONG FGEN WHICH SLOPES NORTHWARD FROM NEAR
700 MB NEAR FWA TO NEAR 400 MB OVER HTL AS THE JET STREAK MOVES
THROUGH. OF COURSE THAT SORT DYNAMIC DEMANDS A LOW TO MID LEVEL
RESPONSE WHICH IS TO LIFT AIR NORTHWARD TOWARD MICHIGAN AS THIS
JET FEATURE MOVES THROUGH. SO...THE KEY TO WHERE THE HEAVY SNOW
FALLS REALLY IS JUST WHERE THE AXIS OF THE JET STREAK IS. SINCE
THE JET STREAK ASIX IS JUST SOUTH OF MICHIGAN THAT IS WHERE THE
HEAVIEST SNOW IS LIKELY TO FALL. STILL THERE IS MID LEVEL LIFT
OVER LOWER MICHIGAN SO WE WILL SEE SOME LIGHT SNOW FROM THIS
EVENT. I AM THINKING AROUND AN INCH NEAR GRR TO 2 TO 3 INCHES JUST
SOUTH OF INTERSTATE 94. COLD AIR FOLLOWING THE JET STREAK WILL
LEAD TO A SHALLOW LAKE EFFECT SNOW SHOWER EVENT SUNDAY NIGHT BUT
THIS WILL BE NOT MUCH MORE THAN FLURRIES SINCE INVERSION HEIGHTS
WILL BE BELOW 5000 FT.

OTHERWISE THE LAKE EFFECT SNOW BAND MOVING ONSHORE TODAY WILL
DISSIPATE BY EARLY THIS EVENING LEAVING PARTLY CLOUDY SKIES
TONIGHT. THE CLOUDS IN FROM THE SOUTHWEST WINDS OFF LAKE MICHIGAN
WILL KEEP THE TEMPERATURES FROM FALLING LIKE LAST NIGHT SO LOWS
WILL BE MILDER.

SATURDAY SHOULD SEE SOME CLEARING BY MID AFTERNOON AS WINDS BECOME
MORE SOUTHERLY AND NOT OFF LAKE MICHIGAN ANYMORE. SATURDAY NIGHT
WILL SEE INCREASING MID AND HIGH CLOUDS AS THE SYSTEM SNOW HEADS
THIS WAY.


.LONG TERM...(MONDAY THROUGH FRIDAY)
ISSUED AT 305 PM EST FRI FEB 27 2015

MAIN FOCUS OF THE FCST CONTINUES TO BE THE SYSTEM EXPECTED TO COME
THROUGH DURING THE MON NIGHT THROUGH TUE NIGHT TIME FRAME. THERE ARE
ONLY MINOR CHANGES TO THE THINKING WITH REGARDS TO THIS SYSTEM.
THOSE CHANGES ARE MAINLY THE RESULT OF THE EXACT TRACK OF THE LOW.

WE CONTINUE TO EXPECT PCPN TO DEVELOP AS SNOW LATE MON NIGHT...AFTER
A QUIET PERIOD ON MON WITH HIGH PRESSURE OVERHEAD. PCPN IS EXPECTED
TO START OUT AS SNOW ACROSS THE ENTIRE CWFA OVERNIGHT MON NIGHT INTO
EARLY TUE MORNING. THERE IS FAIRLY GOOD MODEL CONSENSUS THAT TEMPS
ALOFT WILL WARM ABOVE FREEZING BY TUE AFTERNOON...ALLOWING P-TYPES
TO CHANGE OVER TO SOME SLEET AND/OR FREEZING RAIN FOR MOST OF THE
AREA. THIS WILL LIKELY BE BRIEF WHERE TEMPS COME ABOVE FREEZING TUE
AFTERNOON AND EVENING...WHICH IS CURRENTLY EXPECTED TO OCCUR ALONG
AND SOUTH OF I-96.

AREAS NORTH OF I-96 COULD END UP REMAINING ALL SNOW/SLEET/FREEZING
RAIN NORTH OF THE LOW TRACK WHERE TEMPS COULD POTENTIALLY STAY BELOW
FREEZING THE ENTIRE TIME. THIS COULD BE WHERE A DECENT AMOUNT OF
ICING COULD TAKE PLACE.

WE CAN EXPECT FLUCTUATIONS IN THE TRACK OF THE LOW AND PLACEMENT OF
P-TYPES FOR AT LEAST ANOTHER 24 TO 48 HOURS. THIS IS DUE TO THE FACT
THAT THE ENERGY THAT WILL AFFECT THIS SYSTEM IS STILL WELL OVER THE
BERING SEA...WEST OF ALASKA. ONCE IT MOVES OVER THE CONTINENT AND
INTO THE RAOB NETWORK...BETTER SAMPLING SHOULD TAKE PLACE. THE OTHER
MAIN PART OF THIS...THE LOW OVER THE PACIFIC NW...IS ALREADY
STARTING TO BE SAMPLED BETTER.

WE SHOULD SEE A QUICK BURST OF ARCTIC AIR FOLLOW THIS SYSTEM COMING
IN ON WED AND HOLDING INTO THU. SOME LAKE EFFECT WILL BE POSSIBLE AT
THAT TIME. A QUICK MODERATION COMES LATE NEXT WEEK AS THE NRN BRANCH
OF THE JET LIFTS BACK NORTH OF THE AREA. WE WILL SEE A WRLY FLOW
OVER THE AREA WITH THE NEXT CLIPPER SYSTEM POTENTIALLY STAYING NORTH
OF THE BORDER.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1237 PM EST FRI FEB 27 2015

MAIN IMPACT TO AVIATION OPERATIONS WILL BE LAKE EFFECT CLOUDS AND
SOME SNOW SHOWERS MOVING INLAND THIS AFTERNOON. THE CLOUD LEVEL
WINDS ARE SHIFTING ONSHORE THIS AFTERNOON...WHICH IS HELPING TO
PUSH LAKE EFFECT INLAND. SOME IFR WAS REPORTED AT KMKG
EARLIER...WHICH HAS SINCE MOVED INLAND. WE EXPECT THAT THE SNOW
SHOWERS WILL WEAKEN THIS AFTERNOON AS THE MAIN BAND MOVING ONSHORE
DISPERSES. KGRR COULD SEE A FEW OF THESE...BUT WE EXPECT MAINLY
MVFR WITH ANY SNOW SHOWERS. SOME BRIEF AND ISOLATED IFR WILL BE
POSSIBLE.

LAKE EFFECT WILL CLEAR OUT OF THE AREA ACROSS THE SRN TERMINALS
THIS EVENING AS THE FLOW BECOMES SW IN THE CLOUD LAYER. KMKG AND
KGRR WILL HOLD ON TO THE VFR DECK INTO SAT MORNING BEFORE IT
EVENTUALLY MOVES NORTH/DISSIPATES. CAN NOT RULE OUT SOME OF THE
CIGS GOING MVFR OVERNIGHT.


&&

.HYDROLOGY...
ISSUED AT 1202 PM EST FRI FEB 27 2015

THE BATTLE CREEK SITE (BTCM4) ON THE KALAMAZOO RIVER HAS SHOWN
SOME ERRONEOUS DATA THROUGH THE MORNING HOURS. THIS HAS BEEN
DETERMINED TO BE CAUSED BY THE EXTREME COLD THAT SETTLED IN
OVERNIGHT. IT HAS SINCE SHOWN SIGNS OF RETURNING BACK TO ITS
ORIGINAL READING AS A RESULT OF THE SUNSHINE THIS AFTERNOON.
COORDINATION WITH LOCAL OFFICIALS HAS NOT REVEALED ANY NEED FOR
CONCERN.

WHILE AREA STREAMS AND RIVERS HAVE BEEN STABLE FOR SEVERAL WEEKS
NOW A RATHER ACTIVE PERIOD AND GRADUAL WARMING TREND IS EXPECTED.
THIS DOES NOT NECESSARILY RAISE ALARM BUT WE SHOULD HEED SPECIFICS
AS TEMPERATURES BEGIN TO INCREASE AND PRECIPITATION APPROACHES.
TOTAL PRECIPITATION THROUGH THE NEXT SEVEN DAYS IS ANTICIPATED TO
REMAIN UNDER AN INCH. THE REAL QUESTION COMES ON TUESDAY...AS TO
THE EXTENT OF WARMTH...PRECIPITATION AMOUNTS AND PRECIPITATION
TYPE. THAT SAID...WE WOULD NEED A MEANINGFUL AMOUNT OF MOISTURE
IN A SHORT PERIOD OF TIME...COUPLED WITH AN EXTENDED PERIOD OF
WARMTH TO CREATE INSTABILITY IN THE CURRENT ICE COVER. AS OF
NOW...NO REAL ISSUES ARE EXPECTED BUT RIVERS WILL BE MONITORED
THROUGH THE NEXT WEEK.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&

$$

SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...NJJ
AVIATION...NJJ
HYDROLOGY...JAM







000
FXUS63 KGRR 271737
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1237 PM EST FRI FEB 27 2015

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 320 AM EST FRI FEB 27 2015

CONTINUED COLD THROUGH THE WEEKEND WITH SOME LIGHT SNOW POSSIBLE
NEAR LAKE MICHIGAN TODAY AND MORE WIDESPREAD SNOW EXPECTED SUNDAY
AND SUNDAY NIGHT. A BRIEF WARMUP IS EXPECTED ALONG WITH A MIX OF
RAIN AND SNOW TUESDAY AND TUESDAY NIGHT...BEFORE COLD WEATHER
RETURNS FOR THE REST OF NEXT WEEK.

&&

.UPDATE...
ISSUED AT 1030 AM EST FRI FEB 27 2015

I UPDATED THE FORECAST TO HAVE THE LAKE SNOW BAND AS IT MOVES ON
SHORE BE MORE PERSISTENT. THE LATEST NAM12 SHOWS DECENT LIFT IN
THE DGZ WITH ENOUGH MOISTURE TO KEEP THE SNOW BAND GOING INTO
EARLY THIS AFTERNOON. OTHERWISE THE ON GOING FORECAST LOOKS GREAT.

&&

.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 320 AM EST FRI FEB 27 2015

LITTLE IMPACT WEATHER IN THE SHORT TERM WITH VERY COLD
TEMPERATURES REMAINING AND ONLY SOME LIGHT SNOW POSSIBLE NEAR
LAKE MICHIGAN TODAY. OTHERWISE...MONITORING THE APPROACH OF A
SYSTEM LATE SATURDAY THAT DOES NOT APPEAR TO MOVE THE POSSIBILITY
OF SNOW INTO MICHIGAN UNTIL SUNDAY.

VERY COLD START TO TODAY WITH TEMPERATURES WELL BELOW ZERO AND
SLOW RECOVERY LEADING TO ANOTHER DAY WITH HIGH TEMPERATURES IN
THE 10-20 DEGREE ABOVE ZERO RANGE. SNOW BAND CURRENTLY OVER LAKE
MICHIGAN TO CONTINUE TO SLOWLY WORK INLAND THIS MORNING WEAKENING
AS IT MOVES OVER LAND. A FEW LOCATIONS ALONG THE COAST COULD SEE
A SLOW INCH OR SO THIS MORNING...BUT FOR THE MOST PART JUST A FEW
FLURRIES WEST OF US-131 TODAY AND NO SIGNIFICANT IMPACTS
EXPECTED.

ANOTHER VERY COLD NIGHT AGAIN TONIGHT WITH SOME CLEARING SKIES
BRINGING NEAR ZERO AND BELOW ZERO TEMPERATURES TO LOWER MICHIGAN
AGAIN. SATURDAY AGAIN A COLD DAY WITH INCREASING CLOUDS SATURDAY
NIGHT AHEAD OF AN APPROACHING SYSTEM THAT MAY BRING SOME SNOW TO
THE AREA SUNDAY.

.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 320 AM EST THU FEB 26 2015

FOCUS REMAINS ON TWO EVENTS IN THE LONG TERM...NAMELY SNOW ON SUNDAY
AND THEN THE SYSTEM FOR NEXT WEEK TUESDAY INTO WEDNESDAY.

REGARDING THE SUNDAY SYSTEM IT APPEARS TO HAVE NUDGED A BIT TO THE
SOUTH...AS THE UPPER WAVE DRIVING THE SNOW DIGS INTO THE GREAT LAKES
REGION MORE. THE AXIS OF HEAVIEST PRECIPITATION IS SOLIDLY ACROSS
INDIANA. THE SNOW SPREADS IN LATE SATURDAY NIGHT WITH THE BULK
FALLING DURING THE DAY ON SUNDAY. THE SNOW SHOULD WIND DOWN SUNDAY
EVENING. AMOUNTS MAY BE JUST A TOUCH LOWER THAN WHAT WE WERE
THINKING LAST NIGHT. MAYBE AN INCH OR SO ACROSS CENTRAL LOWER
MI...AND 2-4 INCHES TOWARDS I-94.

A BRIEF LULL IN THE WEATHER FOR SUNDAY NIGHT INTO MONDAY NIGHT
BEFORE FOCUS SHIFTS TO THE NEXT SYSTEM. THE TUESDAY SYSTEM HAS LOST
A BIT OF MODEL TO MODEL CONTINUITY AGAIN WITH THE GFS BEING
QUICKER...DEEPER AND FURTHER NORTH. THE ECMWF IS SLOWER AND
EVENTUALLY NEARS THE SAME DEPTH OF THE GFS. THE CANADIAN DOESN/T
OFFER MUCH OF A LEAN EITHER WAY BEING WEAKER AND SOUTH.

AT THIS POINT TAKING A STAY THE COURSE TYPE OF APPROACH WITH THE
TUES/WED SYSTEM GIVEN HOW IT EVOLVES. ESSENTIALLY IT IS DRIVEN BY A
SHORTWAVE EJECTING OUT OF THE SOUTHWEST U.S. UPPER TROUGH. THESE
TYPE OF SYSTEMS ARE FICKLE AND TOUGH TO NAIL DOWN DETAILS ON
ESPECIALLY AT RANGE IN THE FORECAST.

AT THIS POINT FORECAST IS FOR LIGHT SNOW...LOW CHANCES...DEVELOPING
MONDAY NIGHT. ON TUESDAY A SNOW...SLEET...FREEZING RAIN MIX CHANGING
TO FREEZING RAIN AND RAIN. BOTH THE GFS AND ECMWF SHOW A SURGE OF
WARMER AIR INTO THE CWA...THE EURO IS JUST SLOWER WITH IT. MY
INTUITION TELLS ME TO GO WITH THE SLOWER EURO GIVEN A DIGGING TROUGH
DOWN THE WEST COAST. SLOWER IS USUALLY THE WAY TO GO GIVEN THIS
PATTERN. MIX OF RAIN AND SNOW TUESDAY NIGHT CHANGING BACK TO SNOW ON
WEDNESDAY. BOTTOM LINE WE HAVE A WAYS TO GO YET IN DETERMINING THE
FINE DETAILS WITH THIS SYSTEM. BIGGEST IMPACT IN OUR AREA LOOKS TO
BE THE FREEZING PRECIPITATION AS THE HEAVIER SNOW SWATH LAYS DOWN
ACROSS NORTHERN LOWER. STAY TUNED FOR FURTHER MODEL ADJUSTMENTS
THOUGH.

COLDER AIR SWEEPS IN BEHIND THE SYSTEM FOR THURSDAY WITH LAKE SNOWS
LIKELY.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1237 PM EST FRI FEB 27 2015

MAIN IMPACT TO AVIATION OPERATIONS WILL BE LAKE EFFECT CLOUDS AND
SOME SNOW SHOWERS MOVING INLAND THIS AFTERNOON. THE CLOUD LEVEL
WINDS ARE SHIFTING ONSHORE THIS AFTERNOON...WHICH IS HELPING TO
PUSH LAKE EFFECT INLAND. SOME IFR WAS REPORTED AT KMKG
EARLIER...WHICH HAS SINCE MOVED INLAND. WE EXPECT THAT THE SNOW
SHOWERS WILL WEAKEN THIS AFTERNOON AS THE MAIN BAND MOVING ONSHORE
DISPERSES. KGRR COULD SEE A FEW OF THESE...BUT WE EXPECT MAINLY
MVFR WITH ANY SNOW SHOWERS. SOME BRIEF AND ISOLATED IFR WILL BE
POSSIBLE.

LAKE EFFECT WILL CLEAR OUT OF THE AREA ACROSS THE SRN TERMINALS
THIS EVENING AS THE FLOW BECOMES SW IN THE CLOUD LAYER. KMKG AND
KGRR WILL HOLD ON TO THE VFR DECK INTO SAT MORNING BEFORE IT
EVENTUALLY MOVES NORTH/DISSIPATES. CAN NOT RULE OUT SOME OF THE
CIGS GOING MVFR OVERNIGHT.

&&

.HYDROLOGY...
ISSUED AT 1202 PM EST FRI FEB 27 2015

THE BATTLE CREEK SITE (BTCM4) ON THE KALAMAZOO RIVER HAS SHOWN
SOME ERRONEOUS DATA THROUGH THE MORNING HOURS. THIS HAS BEEN
DETERMINED TO BE CAUSED BY THE EXTREME COLD THAT SETTLED IN
OVERNIGHT. IT HAS SINCE SHOWN SIGNS OF RETURNING BACK TO ITS
ORIGINAL READING AS A RESULT OF THE SUNSHINE THIS AFTERNOON.
COORDINATION WITH LOCAL OFFICIALS HAS NOT REVEALED ANY NEED FOR
CONCERN.

WHILE AREA STREAMS AND RIVERS HAVE BEEN STABLE FOR SEVERAL WEEKS
NOW A RATHER ACTIVE PERIOD AND GRADUAL WARMING TREND IS EXPECTED.
THIS DOES NOT NECESSARILY RAISE ALARM BUT WE SHOULD HEED SPECIFICS
AS TEMPERATURES BEGIN TO INCREASE AND PRECIPITATION APPROACHES.
TOTAL PRECIPITATION THROUGH THE NEXT SEVEN DAYS IS ANTICIPATED TO
REMAIN UNDER AN INCH. THE REAL QUESTION COMES ON TUESDAY...AS TO
THE EXTENT OF WARMTH...PRECIPITATION AMOUNTS AND PRECIPITATION
TYPE. THAT SAID...WE WOULD NEED A MEANINGFUL AMOUNT OF MOISTURE
IN A SHORT PERIOD OF TIME...COUPLED WITH AN EXTENDED PERIOD OF
WARMTH TO CREATE INSTABILITY IN THE CURRENT ICE COVER. AS OF
NOW...NO REAL ISSUES ARE EXPECTED BUT RIVERS WILL BE MONITORED
THROUGH THE NEXT WEEK.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&

$$

UPDATE...WDM
SYNOPSIS...MACZKO
SHORT TERM...MACZKO
LONG TERM...DUKE
AVIATION...NJJ
HYDROLOGY...JAM








000
FXUS63 KGRR 271737
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1237 PM EST FRI FEB 27 2015

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 320 AM EST FRI FEB 27 2015

CONTINUED COLD THROUGH THE WEEKEND WITH SOME LIGHT SNOW POSSIBLE
NEAR LAKE MICHIGAN TODAY AND MORE WIDESPREAD SNOW EXPECTED SUNDAY
AND SUNDAY NIGHT. A BRIEF WARMUP IS EXPECTED ALONG WITH A MIX OF
RAIN AND SNOW TUESDAY AND TUESDAY NIGHT...BEFORE COLD WEATHER
RETURNS FOR THE REST OF NEXT WEEK.

&&

.UPDATE...
ISSUED AT 1030 AM EST FRI FEB 27 2015

I UPDATED THE FORECAST TO HAVE THE LAKE SNOW BAND AS IT MOVES ON
SHORE BE MORE PERSISTENT. THE LATEST NAM12 SHOWS DECENT LIFT IN
THE DGZ WITH ENOUGH MOISTURE TO KEEP THE SNOW BAND GOING INTO
EARLY THIS AFTERNOON. OTHERWISE THE ON GOING FORECAST LOOKS GREAT.

&&

.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 320 AM EST FRI FEB 27 2015

LITTLE IMPACT WEATHER IN THE SHORT TERM WITH VERY COLD
TEMPERATURES REMAINING AND ONLY SOME LIGHT SNOW POSSIBLE NEAR
LAKE MICHIGAN TODAY. OTHERWISE...MONITORING THE APPROACH OF A
SYSTEM LATE SATURDAY THAT DOES NOT APPEAR TO MOVE THE POSSIBILITY
OF SNOW INTO MICHIGAN UNTIL SUNDAY.

VERY COLD START TO TODAY WITH TEMPERATURES WELL BELOW ZERO AND
SLOW RECOVERY LEADING TO ANOTHER DAY WITH HIGH TEMPERATURES IN
THE 10-20 DEGREE ABOVE ZERO RANGE. SNOW BAND CURRENTLY OVER LAKE
MICHIGAN TO CONTINUE TO SLOWLY WORK INLAND THIS MORNING WEAKENING
AS IT MOVES OVER LAND. A FEW LOCATIONS ALONG THE COAST COULD SEE
A SLOW INCH OR SO THIS MORNING...BUT FOR THE MOST PART JUST A FEW
FLURRIES WEST OF US-131 TODAY AND NO SIGNIFICANT IMPACTS
EXPECTED.

ANOTHER VERY COLD NIGHT AGAIN TONIGHT WITH SOME CLEARING SKIES
BRINGING NEAR ZERO AND BELOW ZERO TEMPERATURES TO LOWER MICHIGAN
AGAIN. SATURDAY AGAIN A COLD DAY WITH INCREASING CLOUDS SATURDAY
NIGHT AHEAD OF AN APPROACHING SYSTEM THAT MAY BRING SOME SNOW TO
THE AREA SUNDAY.

.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 320 AM EST THU FEB 26 2015

FOCUS REMAINS ON TWO EVENTS IN THE LONG TERM...NAMELY SNOW ON SUNDAY
AND THEN THE SYSTEM FOR NEXT WEEK TUESDAY INTO WEDNESDAY.

REGARDING THE SUNDAY SYSTEM IT APPEARS TO HAVE NUDGED A BIT TO THE
SOUTH...AS THE UPPER WAVE DRIVING THE SNOW DIGS INTO THE GREAT LAKES
REGION MORE. THE AXIS OF HEAVIEST PRECIPITATION IS SOLIDLY ACROSS
INDIANA. THE SNOW SPREADS IN LATE SATURDAY NIGHT WITH THE BULK
FALLING DURING THE DAY ON SUNDAY. THE SNOW SHOULD WIND DOWN SUNDAY
EVENING. AMOUNTS MAY BE JUST A TOUCH LOWER THAN WHAT WE WERE
THINKING LAST NIGHT. MAYBE AN INCH OR SO ACROSS CENTRAL LOWER
MI...AND 2-4 INCHES TOWARDS I-94.

A BRIEF LULL IN THE WEATHER FOR SUNDAY NIGHT INTO MONDAY NIGHT
BEFORE FOCUS SHIFTS TO THE NEXT SYSTEM. THE TUESDAY SYSTEM HAS LOST
A BIT OF MODEL TO MODEL CONTINUITY AGAIN WITH THE GFS BEING
QUICKER...DEEPER AND FURTHER NORTH. THE ECMWF IS SLOWER AND
EVENTUALLY NEARS THE SAME DEPTH OF THE GFS. THE CANADIAN DOESN/T
OFFER MUCH OF A LEAN EITHER WAY BEING WEAKER AND SOUTH.

AT THIS POINT TAKING A STAY THE COURSE TYPE OF APPROACH WITH THE
TUES/WED SYSTEM GIVEN HOW IT EVOLVES. ESSENTIALLY IT IS DRIVEN BY A
SHORTWAVE EJECTING OUT OF THE SOUTHWEST U.S. UPPER TROUGH. THESE
TYPE OF SYSTEMS ARE FICKLE AND TOUGH TO NAIL DOWN DETAILS ON
ESPECIALLY AT RANGE IN THE FORECAST.

AT THIS POINT FORECAST IS FOR LIGHT SNOW...LOW CHANCES...DEVELOPING
MONDAY NIGHT. ON TUESDAY A SNOW...SLEET...FREEZING RAIN MIX CHANGING
TO FREEZING RAIN AND RAIN. BOTH THE GFS AND ECMWF SHOW A SURGE OF
WARMER AIR INTO THE CWA...THE EURO IS JUST SLOWER WITH IT. MY
INTUITION TELLS ME TO GO WITH THE SLOWER EURO GIVEN A DIGGING TROUGH
DOWN THE WEST COAST. SLOWER IS USUALLY THE WAY TO GO GIVEN THIS
PATTERN. MIX OF RAIN AND SNOW TUESDAY NIGHT CHANGING BACK TO SNOW ON
WEDNESDAY. BOTTOM LINE WE HAVE A WAYS TO GO YET IN DETERMINING THE
FINE DETAILS WITH THIS SYSTEM. BIGGEST IMPACT IN OUR AREA LOOKS TO
BE THE FREEZING PRECIPITATION AS THE HEAVIER SNOW SWATH LAYS DOWN
ACROSS NORTHERN LOWER. STAY TUNED FOR FURTHER MODEL ADJUSTMENTS
THOUGH.

COLDER AIR SWEEPS IN BEHIND THE SYSTEM FOR THURSDAY WITH LAKE SNOWS
LIKELY.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1237 PM EST FRI FEB 27 2015

MAIN IMPACT TO AVIATION OPERATIONS WILL BE LAKE EFFECT CLOUDS AND
SOME SNOW SHOWERS MOVING INLAND THIS AFTERNOON. THE CLOUD LEVEL
WINDS ARE SHIFTING ONSHORE THIS AFTERNOON...WHICH IS HELPING TO
PUSH LAKE EFFECT INLAND. SOME IFR WAS REPORTED AT KMKG
EARLIER...WHICH HAS SINCE MOVED INLAND. WE EXPECT THAT THE SNOW
SHOWERS WILL WEAKEN THIS AFTERNOON AS THE MAIN BAND MOVING ONSHORE
DISPERSES. KGRR COULD SEE A FEW OF THESE...BUT WE EXPECT MAINLY
MVFR WITH ANY SNOW SHOWERS. SOME BRIEF AND ISOLATED IFR WILL BE
POSSIBLE.

LAKE EFFECT WILL CLEAR OUT OF THE AREA ACROSS THE SRN TERMINALS
THIS EVENING AS THE FLOW BECOMES SW IN THE CLOUD LAYER. KMKG AND
KGRR WILL HOLD ON TO THE VFR DECK INTO SAT MORNING BEFORE IT
EVENTUALLY MOVES NORTH/DISSIPATES. CAN NOT RULE OUT SOME OF THE
CIGS GOING MVFR OVERNIGHT.

&&

.HYDROLOGY...
ISSUED AT 1202 PM EST FRI FEB 27 2015

THE BATTLE CREEK SITE (BTCM4) ON THE KALAMAZOO RIVER HAS SHOWN
SOME ERRONEOUS DATA THROUGH THE MORNING HOURS. THIS HAS BEEN
DETERMINED TO BE CAUSED BY THE EXTREME COLD THAT SETTLED IN
OVERNIGHT. IT HAS SINCE SHOWN SIGNS OF RETURNING BACK TO ITS
ORIGINAL READING AS A RESULT OF THE SUNSHINE THIS AFTERNOON.
COORDINATION WITH LOCAL OFFICIALS HAS NOT REVEALED ANY NEED FOR
CONCERN.

WHILE AREA STREAMS AND RIVERS HAVE BEEN STABLE FOR SEVERAL WEEKS
NOW A RATHER ACTIVE PERIOD AND GRADUAL WARMING TREND IS EXPECTED.
THIS DOES NOT NECESSARILY RAISE ALARM BUT WE SHOULD HEED SPECIFICS
AS TEMPERATURES BEGIN TO INCREASE AND PRECIPITATION APPROACHES.
TOTAL PRECIPITATION THROUGH THE NEXT SEVEN DAYS IS ANTICIPATED TO
REMAIN UNDER AN INCH. THE REAL QUESTION COMES ON TUESDAY...AS TO
THE EXTENT OF WARMTH...PRECIPITATION AMOUNTS AND PRECIPITATION
TYPE. THAT SAID...WE WOULD NEED A MEANINGFUL AMOUNT OF MOISTURE
IN A SHORT PERIOD OF TIME...COUPLED WITH AN EXTENDED PERIOD OF
WARMTH TO CREATE INSTABILITY IN THE CURRENT ICE COVER. AS OF
NOW...NO REAL ISSUES ARE EXPECTED BUT RIVERS WILL BE MONITORED
THROUGH THE NEXT WEEK.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&

$$

UPDATE...WDM
SYNOPSIS...MACZKO
SHORT TERM...MACZKO
LONG TERM...DUKE
AVIATION...NJJ
HYDROLOGY...JAM







000
FXUS63 KGRR 271703
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1203 PM EST FRI FEB 27 2015

LATEST UPDATE...
HYDRO

.SYNOPSIS...
ISSUED AT 320 AM EST FRI FEB 27 2015

CONTINUED COLD THROUGH THE WEEKEND WITH SOME LIGHT SNOW POSSIBLE
NEAR LAKE MICHIGAN TODAY AND MORE WIDESPREAD SNOW EXPECTED SUNDAY
AND SUNDAY NIGHT. A BRIEF WARMUP IS EXPECTED ALONG WITH A MIX OF
RAIN AND SNOW TUESDAY AND TUESDAY NIGHT...BEFORE COLD WEATHER
RETURNS FOR THE REST OF NEXT WEEK.

&&

.UPDATE...
ISSUED AT 1030 AM EST FRI FEB 27 2015

I UPDATED THE FORECAST TO HAVE THE LAKE SNOW BAND AS IT MOVES ON
SHORE BE MORE PERSISTENT. THE LATEST NAM12 SHOWS DECENT LIFT IN
THE DGZ WITH ENOUGH MOISTURE TO KEEP THE SNOW BAND GOING INTO
EARLY THIS AFTERNOON. OTHERWISE THE ON GOING FORECAST LOOKS GREAT.

&&

.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 320 AM EST FRI FEB 27 2015

LITTLE IMPACT WEATHER IN THE SHORT TERM WITH VERY COLD
TEMPERATURES REMAINING AND ONLY SOME LIGHT SNOW POSSIBLE NEAR
LAKE MICHIGAN TODAY. OTHERWISE...MONITORING THE APPROACH OF A
SYSTEM LATE SATURDAY THAT DOES NOT APPEAR TO MOVE THE POSSIBILITY
OF SNOW INTO MICHIGAN UNTIL SUNDAY.

VERY COLD START TO TODAY WITH TEMPERATURES WELL BELOW ZERO AND
SLOW RECOVERY LEADING TO ANOTHER DAY WITH HIGH TEMPERATURES IN
THE 10-20 DEGREE ABOVE ZERO RANGE. SNOW BAND CURRENTLY OVER LAKE
MICHIGAN TO CONTINUE TO SLOWLY WORK INLAND THIS MORNING WEAKENING
AS IT MOVES OVER LAND. A FEW LOCATIONS ALONG THE COAST COULD SEE
A SLOW INCH OR SO THIS MORNING...BUT FOR THE MOST PART JUST A FEW
FLURRIES WEST OF US-131 TODAY AND NO SIGNIFICANT IMPACTS
EXPECTED.

ANOTHER VERY COLD NIGHT AGAIN TONIGHT WITH SOME CLEARING SKIES
BRINGING NEAR ZERO AND BELOW ZERO TEMPERATURES TO LOWER MICHIGAN
AGAIN. SATURDAY AGAIN A COLD DAY WITH INCREASING CLOUDS SATURDAY
NIGHT AHEAD OF AN APPROACHING SYSTEM THAT MAY BRING SOME SNOW TO
THE AREA SUNDAY.

.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 320 AM EST THU FEB 26 2015

FOCUS REMAINS ON TWO EVENTS IN THE LONG TERM...NAMELY SNOW ON SUNDAY
AND THEN THE SYSTEM FOR NEXT WEEK TUESDAY INTO WEDNESDAY.

REGARDING THE SUNDAY SYSTEM IT APPEARS TO HAVE NUDGED A BIT TO THE
SOUTH...AS THE UPPER WAVE DRIVING THE SNOW DIGS INTO THE GREAT LAKES
REGION MORE. THE AXIS OF HEAVIEST PRECIPITATION IS SOLIDLY ACROSS
INDIANA. THE SNOW SPREADS IN LATE SATURDAY NIGHT WITH THE BULK
FALLING DURING THE DAY ON SUNDAY. THE SNOW SHOULD WIND DOWN SUNDAY
EVENING. AMOUNTS MAY BE JUST A TOUCH LOWER THAN WHAT WE WERE
THINKING LAST NIGHT. MAYBE AN INCH OR SO ACROSS CENTRAL LOWER
MI...AND 2-4 INCHES TOWARDS I-94.

A BRIEF LULL IN THE WEATHER FOR SUNDAY NIGHT INTO MONDAY NIGHT
BEFORE FOCUS SHIFTS TO THE NEXT SYSTEM. THE TUESDAY SYSTEM HAS LOST
A BIT OF MODEL TO MODEL CONTINUITY AGAIN WITH THE GFS BEING
QUICKER...DEEPER AND FURTHER NORTH. THE ECMWF IS SLOWER AND
EVENTUALLY NEARS THE SAME DEPTH OF THE GFS. THE CANADIAN DOESN/T
OFFER MUCH OF A LEAN EITHER WAY BEING WEAKER AND SOUTH.

AT THIS POINT TAKING A STAY THE COURSE TYPE OF APPROACH WITH THE
TUES/WED SYSTEM GIVEN HOW IT EVOLVES. ESSENTIALLY IT IS DRIVEN BY A
SHORTWAVE EJECTING OUT OF THE SOUTHWEST U.S. UPPER TROUGH. THESE
TYPE OF SYSTEMS ARE FICKLE AND TOUGH TO NAIL DOWN DETAILS ON
ESPECIALLY AT RANGE IN THE FORECAST.

AT THIS POINT FORECAST IS FOR LIGHT SNOW...LOW CHANCES...DEVELOPING
MONDAY NIGHT. ON TUESDAY A SNOW...SLEET...FREEZING RAIN MIX CHANGING
TO FREEZING RAIN AND RAIN. BOTH THE GFS AND ECMWF SHOW A SURGE OF
WARMER AIR INTO THE CWA...THE EURO IS JUST SLOWER WITH IT. MY
INTUITION TELLS ME TO GO WITH THE SLOWER EURO GIVEN A DIGGING TROUGH
DOWN THE WEST COAST. SLOWER IS USUALLY THE WAY TO GO GIVEN THIS
PATTERN. MIX OF RAIN AND SNOW TUESDAY NIGHT CHANGING BACK TO SNOW ON
WEDNESDAY. BOTTOM LINE WE HAVE A WAYS TO GO YET IN DETERMINING THE
FINE DETAILS WITH THIS SYSTEM. BIGGEST IMPACT IN OUR AREA LOOKS TO
BE THE FREEZING PRECIPITATION AS THE HEAVIER SNOW SWATH LAYS DOWN
ACROSS NORTHERN LOWER. STAY TUNED FOR FURTHER MODEL ADJUSTMENTS
THOUGH.

COLDER AIR SWEEPS IN BEHIND THE SYSTEM FOR THURSDAY WITH LAKE SNOWS
LIKELY.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 709 AM EST FRI FEB 27 2015

WINDS ARE TURNING ON SHORE THIS MORNING AND CLOUDS THAT HAVE BEEN
OUT OVER THE LAKE WILL PUSH INLAND THROUGH THE TAF SITES TODAY.
THERE WILL BE A FEW FLURRIES TOWARDS LAKE MICHIGAN AS WELL.
SCT-BKN CLOUDS WITH BASES OF 3500-5000FT CAN BE EXPECTED. WINDS
FROM THE WEST-SOUTHWEST AT 8-12 KNOTS SHOULD DEVELOP TOWARDS
MIDDAY AND CONTINUE THROUGH THE AFTERNOON.

THE CLOUDS SHOULD SCATTER OUT TONIGHT IN MOST LOCATIONS...BUT MAY
CONTINUE BROKEN THROUGH THE NIGHT AT KMKG.

THERE ARE HINTS IN MODEL DATA THAT THE CEILINGS THIS AFTERNOON AND
OVERNIGHT MAY DIP INTO THE MVFR CATEGORY BETWEEN 2000-3000FT. DID
NOT INCLUDE MVFR CIGS IN THE TAFS AT THIS POINT.


&&

.HYDROLOGY...
ISSUED AT 1202 PM EST FRI FEB 27 2015

THE BATTLE CREEK SITE (BTCM4) ON THE KALAMAZOO RIVER HAS SHOWN
SOME ERRONEOUS DATA THROUGH THE MORNING HOURS. THIS HAS BEEN
DETERMINED TO BE CAUSED BY THE EXTREME COLD THAT SETTLED IN
OVERNIGHT. IT HAS SINCE SHOWN SIGNS OF RETURNING BACK TO ITS
ORIGINAL READING AS A RESULT OF THE SUNSHINE THIS AFTERNOON.
COORDINATION WITH LOCAL OFFICIALS HAS NOT REVEALED ANY NEED FOR
CONCERN.

WHILE AREA STREAMS AND RIVERS HAVE BEEN STABLE FOR SEVERAL WEEKS
NOW A RATHER ACTIVE PERIOD AND GRADUAL WARMING TREND IS EXPECTED.
THIS DOES NOT NECESSARILY RAISE ALARM BUT WE SHOULD HEED SPECIFICS
AS TEMPERATURES BEGIN TO INCREASE AND PRECIPITATION APPROACHES.
TOTAL PRECIPITATION THROUGH THE NEXT SEVEN DAYS IS ANTICIPATED TO
REMAIN UNDER AN INCH. THE REAL QUESTION COMES ON TUESDAY...AS TO
THE EXTENT OF WARMTH...PRECIPITATION AMOUNTS AND PRECIPITATION
TYPE. THAT SAID...WE WOULD NEED A MEANINGFUL AMOUNT OF MOISTURE
IN A SHORT PERIOD OF TIME...COUPLED WITH AN EXTENDED PERIOD OF
WARMTH TO CREATE INSTABILITY IN THE CURRENT ICE COVER. AS OF
NOW...NO REAL ISSUES ARE EXPECTED BUT RIVERS WILL BE MONITORED
THROUGH THE NEXT WEEK.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&

$$

UPDATE...WDM
SYNOPSIS...MACZKO
SHORT TERM...MACZKO
LONG TERM...DUKE
AVIATION...DUKE
HYDROLOGY...JAM








000
FXUS63 KGRR 271703
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1203 PM EST FRI FEB 27 2015

LATEST UPDATE...
HYDRO

.SYNOPSIS...
ISSUED AT 320 AM EST FRI FEB 27 2015

CONTINUED COLD THROUGH THE WEEKEND WITH SOME LIGHT SNOW POSSIBLE
NEAR LAKE MICHIGAN TODAY AND MORE WIDESPREAD SNOW EXPECTED SUNDAY
AND SUNDAY NIGHT. A BRIEF WARMUP IS EXPECTED ALONG WITH A MIX OF
RAIN AND SNOW TUESDAY AND TUESDAY NIGHT...BEFORE COLD WEATHER
RETURNS FOR THE REST OF NEXT WEEK.

&&

.UPDATE...
ISSUED AT 1030 AM EST FRI FEB 27 2015

I UPDATED THE FORECAST TO HAVE THE LAKE SNOW BAND AS IT MOVES ON
SHORE BE MORE PERSISTENT. THE LATEST NAM12 SHOWS DECENT LIFT IN
THE DGZ WITH ENOUGH MOISTURE TO KEEP THE SNOW BAND GOING INTO
EARLY THIS AFTERNOON. OTHERWISE THE ON GOING FORECAST LOOKS GREAT.

&&

.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 320 AM EST FRI FEB 27 2015

LITTLE IMPACT WEATHER IN THE SHORT TERM WITH VERY COLD
TEMPERATURES REMAINING AND ONLY SOME LIGHT SNOW POSSIBLE NEAR
LAKE MICHIGAN TODAY. OTHERWISE...MONITORING THE APPROACH OF A
SYSTEM LATE SATURDAY THAT DOES NOT APPEAR TO MOVE THE POSSIBILITY
OF SNOW INTO MICHIGAN UNTIL SUNDAY.

VERY COLD START TO TODAY WITH TEMPERATURES WELL BELOW ZERO AND
SLOW RECOVERY LEADING TO ANOTHER DAY WITH HIGH TEMPERATURES IN
THE 10-20 DEGREE ABOVE ZERO RANGE. SNOW BAND CURRENTLY OVER LAKE
MICHIGAN TO CONTINUE TO SLOWLY WORK INLAND THIS MORNING WEAKENING
AS IT MOVES OVER LAND. A FEW LOCATIONS ALONG THE COAST COULD SEE
A SLOW INCH OR SO THIS MORNING...BUT FOR THE MOST PART JUST A FEW
FLURRIES WEST OF US-131 TODAY AND NO SIGNIFICANT IMPACTS
EXPECTED.

ANOTHER VERY COLD NIGHT AGAIN TONIGHT WITH SOME CLEARING SKIES
BRINGING NEAR ZERO AND BELOW ZERO TEMPERATURES TO LOWER MICHIGAN
AGAIN. SATURDAY AGAIN A COLD DAY WITH INCREASING CLOUDS SATURDAY
NIGHT AHEAD OF AN APPROACHING SYSTEM THAT MAY BRING SOME SNOW TO
THE AREA SUNDAY.

.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 320 AM EST THU FEB 26 2015

FOCUS REMAINS ON TWO EVENTS IN THE LONG TERM...NAMELY SNOW ON SUNDAY
AND THEN THE SYSTEM FOR NEXT WEEK TUESDAY INTO WEDNESDAY.

REGARDING THE SUNDAY SYSTEM IT APPEARS TO HAVE NUDGED A BIT TO THE
SOUTH...AS THE UPPER WAVE DRIVING THE SNOW DIGS INTO THE GREAT LAKES
REGION MORE. THE AXIS OF HEAVIEST PRECIPITATION IS SOLIDLY ACROSS
INDIANA. THE SNOW SPREADS IN LATE SATURDAY NIGHT WITH THE BULK
FALLING DURING THE DAY ON SUNDAY. THE SNOW SHOULD WIND DOWN SUNDAY
EVENING. AMOUNTS MAY BE JUST A TOUCH LOWER THAN WHAT WE WERE
THINKING LAST NIGHT. MAYBE AN INCH OR SO ACROSS CENTRAL LOWER
MI...AND 2-4 INCHES TOWARDS I-94.

A BRIEF LULL IN THE WEATHER FOR SUNDAY NIGHT INTO MONDAY NIGHT
BEFORE FOCUS SHIFTS TO THE NEXT SYSTEM. THE TUESDAY SYSTEM HAS LOST
A BIT OF MODEL TO MODEL CONTINUITY AGAIN WITH THE GFS BEING
QUICKER...DEEPER AND FURTHER NORTH. THE ECMWF IS SLOWER AND
EVENTUALLY NEARS THE SAME DEPTH OF THE GFS. THE CANADIAN DOESN/T
OFFER MUCH OF A LEAN EITHER WAY BEING WEAKER AND SOUTH.

AT THIS POINT TAKING A STAY THE COURSE TYPE OF APPROACH WITH THE
TUES/WED SYSTEM GIVEN HOW IT EVOLVES. ESSENTIALLY IT IS DRIVEN BY A
SHORTWAVE EJECTING OUT OF THE SOUTHWEST U.S. UPPER TROUGH. THESE
TYPE OF SYSTEMS ARE FICKLE AND TOUGH TO NAIL DOWN DETAILS ON
ESPECIALLY AT RANGE IN THE FORECAST.

AT THIS POINT FORECAST IS FOR LIGHT SNOW...LOW CHANCES...DEVELOPING
MONDAY NIGHT. ON TUESDAY A SNOW...SLEET...FREEZING RAIN MIX CHANGING
TO FREEZING RAIN AND RAIN. BOTH THE GFS AND ECMWF SHOW A SURGE OF
WARMER AIR INTO THE CWA...THE EURO IS JUST SLOWER WITH IT. MY
INTUITION TELLS ME TO GO WITH THE SLOWER EURO GIVEN A DIGGING TROUGH
DOWN THE WEST COAST. SLOWER IS USUALLY THE WAY TO GO GIVEN THIS
PATTERN. MIX OF RAIN AND SNOW TUESDAY NIGHT CHANGING BACK TO SNOW ON
WEDNESDAY. BOTTOM LINE WE HAVE A WAYS TO GO YET IN DETERMINING THE
FINE DETAILS WITH THIS SYSTEM. BIGGEST IMPACT IN OUR AREA LOOKS TO
BE THE FREEZING PRECIPITATION AS THE HEAVIER SNOW SWATH LAYS DOWN
ACROSS NORTHERN LOWER. STAY TUNED FOR FURTHER MODEL ADJUSTMENTS
THOUGH.

COLDER AIR SWEEPS IN BEHIND THE SYSTEM FOR THURSDAY WITH LAKE SNOWS
LIKELY.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 709 AM EST FRI FEB 27 2015

WINDS ARE TURNING ON SHORE THIS MORNING AND CLOUDS THAT HAVE BEEN
OUT OVER THE LAKE WILL PUSH INLAND THROUGH THE TAF SITES TODAY.
THERE WILL BE A FEW FLURRIES TOWARDS LAKE MICHIGAN AS WELL.
SCT-BKN CLOUDS WITH BASES OF 3500-5000FT CAN BE EXPECTED. WINDS
FROM THE WEST-SOUTHWEST AT 8-12 KNOTS SHOULD DEVELOP TOWARDS
MIDDAY AND CONTINUE THROUGH THE AFTERNOON.

THE CLOUDS SHOULD SCATTER OUT TONIGHT IN MOST LOCATIONS...BUT MAY
CONTINUE BROKEN THROUGH THE NIGHT AT KMKG.

THERE ARE HINTS IN MODEL DATA THAT THE CEILINGS THIS AFTERNOON AND
OVERNIGHT MAY DIP INTO THE MVFR CATEGORY BETWEEN 2000-3000FT. DID
NOT INCLUDE MVFR CIGS IN THE TAFS AT THIS POINT.


&&

.HYDROLOGY...
ISSUED AT 1202 PM EST FRI FEB 27 2015

THE BATTLE CREEK SITE (BTCM4) ON THE KALAMAZOO RIVER HAS SHOWN
SOME ERRONEOUS DATA THROUGH THE MORNING HOURS. THIS HAS BEEN
DETERMINED TO BE CAUSED BY THE EXTREME COLD THAT SETTLED IN
OVERNIGHT. IT HAS SINCE SHOWN SIGNS OF RETURNING BACK TO ITS
ORIGINAL READING AS A RESULT OF THE SUNSHINE THIS AFTERNOON.
COORDINATION WITH LOCAL OFFICIALS HAS NOT REVEALED ANY NEED FOR
CONCERN.

WHILE AREA STREAMS AND RIVERS HAVE BEEN STABLE FOR SEVERAL WEEKS
NOW A RATHER ACTIVE PERIOD AND GRADUAL WARMING TREND IS EXPECTED.
THIS DOES NOT NECESSARILY RAISE ALARM BUT WE SHOULD HEED SPECIFICS
AS TEMPERATURES BEGIN TO INCREASE AND PRECIPITATION APPROACHES.
TOTAL PRECIPITATION THROUGH THE NEXT SEVEN DAYS IS ANTICIPATED TO
REMAIN UNDER AN INCH. THE REAL QUESTION COMES ON TUESDAY...AS TO
THE EXTENT OF WARMTH...PRECIPITATION AMOUNTS AND PRECIPITATION
TYPE. THAT SAID...WE WOULD NEED A MEANINGFUL AMOUNT OF MOISTURE
IN A SHORT PERIOD OF TIME...COUPLED WITH AN EXTENDED PERIOD OF
WARMTH TO CREATE INSTABILITY IN THE CURRENT ICE COVER. AS OF
NOW...NO REAL ISSUES ARE EXPECTED BUT RIVERS WILL BE MONITORED
THROUGH THE NEXT WEEK.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&

$$

UPDATE...WDM
SYNOPSIS...MACZKO
SHORT TERM...MACZKO
LONG TERM...DUKE
AVIATION...DUKE
HYDROLOGY...JAM







000
FXUS63 KGRR 271703
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1203 PM EST FRI FEB 27 2015

LATEST UPDATE...
HYDRO

.SYNOPSIS...
ISSUED AT 320 AM EST FRI FEB 27 2015

CONTINUED COLD THROUGH THE WEEKEND WITH SOME LIGHT SNOW POSSIBLE
NEAR LAKE MICHIGAN TODAY AND MORE WIDESPREAD SNOW EXPECTED SUNDAY
AND SUNDAY NIGHT. A BRIEF WARMUP IS EXPECTED ALONG WITH A MIX OF
RAIN AND SNOW TUESDAY AND TUESDAY NIGHT...BEFORE COLD WEATHER
RETURNS FOR THE REST OF NEXT WEEK.

&&

.UPDATE...
ISSUED AT 1030 AM EST FRI FEB 27 2015

I UPDATED THE FORECAST TO HAVE THE LAKE SNOW BAND AS IT MOVES ON
SHORE BE MORE PERSISTENT. THE LATEST NAM12 SHOWS DECENT LIFT IN
THE DGZ WITH ENOUGH MOISTURE TO KEEP THE SNOW BAND GOING INTO
EARLY THIS AFTERNOON. OTHERWISE THE ON GOING FORECAST LOOKS GREAT.

&&

.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 320 AM EST FRI FEB 27 2015

LITTLE IMPACT WEATHER IN THE SHORT TERM WITH VERY COLD
TEMPERATURES REMAINING AND ONLY SOME LIGHT SNOW POSSIBLE NEAR
LAKE MICHIGAN TODAY. OTHERWISE...MONITORING THE APPROACH OF A
SYSTEM LATE SATURDAY THAT DOES NOT APPEAR TO MOVE THE POSSIBILITY
OF SNOW INTO MICHIGAN UNTIL SUNDAY.

VERY COLD START TO TODAY WITH TEMPERATURES WELL BELOW ZERO AND
SLOW RECOVERY LEADING TO ANOTHER DAY WITH HIGH TEMPERATURES IN
THE 10-20 DEGREE ABOVE ZERO RANGE. SNOW BAND CURRENTLY OVER LAKE
MICHIGAN TO CONTINUE TO SLOWLY WORK INLAND THIS MORNING WEAKENING
AS IT MOVES OVER LAND. A FEW LOCATIONS ALONG THE COAST COULD SEE
A SLOW INCH OR SO THIS MORNING...BUT FOR THE MOST PART JUST A FEW
FLURRIES WEST OF US-131 TODAY AND NO SIGNIFICANT IMPACTS
EXPECTED.

ANOTHER VERY COLD NIGHT AGAIN TONIGHT WITH SOME CLEARING SKIES
BRINGING NEAR ZERO AND BELOW ZERO TEMPERATURES TO LOWER MICHIGAN
AGAIN. SATURDAY AGAIN A COLD DAY WITH INCREASING CLOUDS SATURDAY
NIGHT AHEAD OF AN APPROACHING SYSTEM THAT MAY BRING SOME SNOW TO
THE AREA SUNDAY.

.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 320 AM EST THU FEB 26 2015

FOCUS REMAINS ON TWO EVENTS IN THE LONG TERM...NAMELY SNOW ON SUNDAY
AND THEN THE SYSTEM FOR NEXT WEEK TUESDAY INTO WEDNESDAY.

REGARDING THE SUNDAY SYSTEM IT APPEARS TO HAVE NUDGED A BIT TO THE
SOUTH...AS THE UPPER WAVE DRIVING THE SNOW DIGS INTO THE GREAT LAKES
REGION MORE. THE AXIS OF HEAVIEST PRECIPITATION IS SOLIDLY ACROSS
INDIANA. THE SNOW SPREADS IN LATE SATURDAY NIGHT WITH THE BULK
FALLING DURING THE DAY ON SUNDAY. THE SNOW SHOULD WIND DOWN SUNDAY
EVENING. AMOUNTS MAY BE JUST A TOUCH LOWER THAN WHAT WE WERE
THINKING LAST NIGHT. MAYBE AN INCH OR SO ACROSS CENTRAL LOWER
MI...AND 2-4 INCHES TOWARDS I-94.

A BRIEF LULL IN THE WEATHER FOR SUNDAY NIGHT INTO MONDAY NIGHT
BEFORE FOCUS SHIFTS TO THE NEXT SYSTEM. THE TUESDAY SYSTEM HAS LOST
A BIT OF MODEL TO MODEL CONTINUITY AGAIN WITH THE GFS BEING
QUICKER...DEEPER AND FURTHER NORTH. THE ECMWF IS SLOWER AND
EVENTUALLY NEARS THE SAME DEPTH OF THE GFS. THE CANADIAN DOESN/T
OFFER MUCH OF A LEAN EITHER WAY BEING WEAKER AND SOUTH.

AT THIS POINT TAKING A STAY THE COURSE TYPE OF APPROACH WITH THE
TUES/WED SYSTEM GIVEN HOW IT EVOLVES. ESSENTIALLY IT IS DRIVEN BY A
SHORTWAVE EJECTING OUT OF THE SOUTHWEST U.S. UPPER TROUGH. THESE
TYPE OF SYSTEMS ARE FICKLE AND TOUGH TO NAIL DOWN DETAILS ON
ESPECIALLY AT RANGE IN THE FORECAST.

AT THIS POINT FORECAST IS FOR LIGHT SNOW...LOW CHANCES...DEVELOPING
MONDAY NIGHT. ON TUESDAY A SNOW...SLEET...FREEZING RAIN MIX CHANGING
TO FREEZING RAIN AND RAIN. BOTH THE GFS AND ECMWF SHOW A SURGE OF
WARMER AIR INTO THE CWA...THE EURO IS JUST SLOWER WITH IT. MY
INTUITION TELLS ME TO GO WITH THE SLOWER EURO GIVEN A DIGGING TROUGH
DOWN THE WEST COAST. SLOWER IS USUALLY THE WAY TO GO GIVEN THIS
PATTERN. MIX OF RAIN AND SNOW TUESDAY NIGHT CHANGING BACK TO SNOW ON
WEDNESDAY. BOTTOM LINE WE HAVE A WAYS TO GO YET IN DETERMINING THE
FINE DETAILS WITH THIS SYSTEM. BIGGEST IMPACT IN OUR AREA LOOKS TO
BE THE FREEZING PRECIPITATION AS THE HEAVIER SNOW SWATH LAYS DOWN
ACROSS NORTHERN LOWER. STAY TUNED FOR FURTHER MODEL ADJUSTMENTS
THOUGH.

COLDER AIR SWEEPS IN BEHIND THE SYSTEM FOR THURSDAY WITH LAKE SNOWS
LIKELY.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 709 AM EST FRI FEB 27 2015

WINDS ARE TURNING ON SHORE THIS MORNING AND CLOUDS THAT HAVE BEEN
OUT OVER THE LAKE WILL PUSH INLAND THROUGH THE TAF SITES TODAY.
THERE WILL BE A FEW FLURRIES TOWARDS LAKE MICHIGAN AS WELL.
SCT-BKN CLOUDS WITH BASES OF 3500-5000FT CAN BE EXPECTED. WINDS
FROM THE WEST-SOUTHWEST AT 8-12 KNOTS SHOULD DEVELOP TOWARDS
MIDDAY AND CONTINUE THROUGH THE AFTERNOON.

THE CLOUDS SHOULD SCATTER OUT TONIGHT IN MOST LOCATIONS...BUT MAY
CONTINUE BROKEN THROUGH THE NIGHT AT KMKG.

THERE ARE HINTS IN MODEL DATA THAT THE CEILINGS THIS AFTERNOON AND
OVERNIGHT MAY DIP INTO THE MVFR CATEGORY BETWEEN 2000-3000FT. DID
NOT INCLUDE MVFR CIGS IN THE TAFS AT THIS POINT.


&&

.HYDROLOGY...
ISSUED AT 1202 PM EST FRI FEB 27 2015

THE BATTLE CREEK SITE (BTCM4) ON THE KALAMAZOO RIVER HAS SHOWN
SOME ERRONEOUS DATA THROUGH THE MORNING HOURS. THIS HAS BEEN
DETERMINED TO BE CAUSED BY THE EXTREME COLD THAT SETTLED IN
OVERNIGHT. IT HAS SINCE SHOWN SIGNS OF RETURNING BACK TO ITS
ORIGINAL READING AS A RESULT OF THE SUNSHINE THIS AFTERNOON.
COORDINATION WITH LOCAL OFFICIALS HAS NOT REVEALED ANY NEED FOR
CONCERN.

WHILE AREA STREAMS AND RIVERS HAVE BEEN STABLE FOR SEVERAL WEEKS
NOW A RATHER ACTIVE PERIOD AND GRADUAL WARMING TREND IS EXPECTED.
THIS DOES NOT NECESSARILY RAISE ALARM BUT WE SHOULD HEED SPECIFICS
AS TEMPERATURES BEGIN TO INCREASE AND PRECIPITATION APPROACHES.
TOTAL PRECIPITATION THROUGH THE NEXT SEVEN DAYS IS ANTICIPATED TO
REMAIN UNDER AN INCH. THE REAL QUESTION COMES ON TUESDAY...AS TO
THE EXTENT OF WARMTH...PRECIPITATION AMOUNTS AND PRECIPITATION
TYPE. THAT SAID...WE WOULD NEED A MEANINGFUL AMOUNT OF MOISTURE
IN A SHORT PERIOD OF TIME...COUPLED WITH AN EXTENDED PERIOD OF
WARMTH TO CREATE INSTABILITY IN THE CURRENT ICE COVER. AS OF
NOW...NO REAL ISSUES ARE EXPECTED BUT RIVERS WILL BE MONITORED
THROUGH THE NEXT WEEK.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&

$$

UPDATE...WDM
SYNOPSIS...MACZKO
SHORT TERM...MACZKO
LONG TERM...DUKE
AVIATION...DUKE
HYDROLOGY...JAM








000
FXUS63 KGRR 271703
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1203 PM EST FRI FEB 27 2015

LATEST UPDATE...
HYDRO

.SYNOPSIS...
ISSUED AT 320 AM EST FRI FEB 27 2015

CONTINUED COLD THROUGH THE WEEKEND WITH SOME LIGHT SNOW POSSIBLE
NEAR LAKE MICHIGAN TODAY AND MORE WIDESPREAD SNOW EXPECTED SUNDAY
AND SUNDAY NIGHT. A BRIEF WARMUP IS EXPECTED ALONG WITH A MIX OF
RAIN AND SNOW TUESDAY AND TUESDAY NIGHT...BEFORE COLD WEATHER
RETURNS FOR THE REST OF NEXT WEEK.

&&

.UPDATE...
ISSUED AT 1030 AM EST FRI FEB 27 2015

I UPDATED THE FORECAST TO HAVE THE LAKE SNOW BAND AS IT MOVES ON
SHORE BE MORE PERSISTENT. THE LATEST NAM12 SHOWS DECENT LIFT IN
THE DGZ WITH ENOUGH MOISTURE TO KEEP THE SNOW BAND GOING INTO
EARLY THIS AFTERNOON. OTHERWISE THE ON GOING FORECAST LOOKS GREAT.

&&

.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 320 AM EST FRI FEB 27 2015

LITTLE IMPACT WEATHER IN THE SHORT TERM WITH VERY COLD
TEMPERATURES REMAINING AND ONLY SOME LIGHT SNOW POSSIBLE NEAR
LAKE MICHIGAN TODAY. OTHERWISE...MONITORING THE APPROACH OF A
SYSTEM LATE SATURDAY THAT DOES NOT APPEAR TO MOVE THE POSSIBILITY
OF SNOW INTO MICHIGAN UNTIL SUNDAY.

VERY COLD START TO TODAY WITH TEMPERATURES WELL BELOW ZERO AND
SLOW RECOVERY LEADING TO ANOTHER DAY WITH HIGH TEMPERATURES IN
THE 10-20 DEGREE ABOVE ZERO RANGE. SNOW BAND CURRENTLY OVER LAKE
MICHIGAN TO CONTINUE TO SLOWLY WORK INLAND THIS MORNING WEAKENING
AS IT MOVES OVER LAND. A FEW LOCATIONS ALONG THE COAST COULD SEE
A SLOW INCH OR SO THIS MORNING...BUT FOR THE MOST PART JUST A FEW
FLURRIES WEST OF US-131 TODAY AND NO SIGNIFICANT IMPACTS
EXPECTED.

ANOTHER VERY COLD NIGHT AGAIN TONIGHT WITH SOME CLEARING SKIES
BRINGING NEAR ZERO AND BELOW ZERO TEMPERATURES TO LOWER MICHIGAN
AGAIN. SATURDAY AGAIN A COLD DAY WITH INCREASING CLOUDS SATURDAY
NIGHT AHEAD OF AN APPROACHING SYSTEM THAT MAY BRING SOME SNOW TO
THE AREA SUNDAY.

.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 320 AM EST THU FEB 26 2015

FOCUS REMAINS ON TWO EVENTS IN THE LONG TERM...NAMELY SNOW ON SUNDAY
AND THEN THE SYSTEM FOR NEXT WEEK TUESDAY INTO WEDNESDAY.

REGARDING THE SUNDAY SYSTEM IT APPEARS TO HAVE NUDGED A BIT TO THE
SOUTH...AS THE UPPER WAVE DRIVING THE SNOW DIGS INTO THE GREAT LAKES
REGION MORE. THE AXIS OF HEAVIEST PRECIPITATION IS SOLIDLY ACROSS
INDIANA. THE SNOW SPREADS IN LATE SATURDAY NIGHT WITH THE BULK
FALLING DURING THE DAY ON SUNDAY. THE SNOW SHOULD WIND DOWN SUNDAY
EVENING. AMOUNTS MAY BE JUST A TOUCH LOWER THAN WHAT WE WERE
THINKING LAST NIGHT. MAYBE AN INCH OR SO ACROSS CENTRAL LOWER
MI...AND 2-4 INCHES TOWARDS I-94.

A BRIEF LULL IN THE WEATHER FOR SUNDAY NIGHT INTO MONDAY NIGHT
BEFORE FOCUS SHIFTS TO THE NEXT SYSTEM. THE TUESDAY SYSTEM HAS LOST
A BIT OF MODEL TO MODEL CONTINUITY AGAIN WITH THE GFS BEING
QUICKER...DEEPER AND FURTHER NORTH. THE ECMWF IS SLOWER AND
EVENTUALLY NEARS THE SAME DEPTH OF THE GFS. THE CANADIAN DOESN/T
OFFER MUCH OF A LEAN EITHER WAY BEING WEAKER AND SOUTH.

AT THIS POINT TAKING A STAY THE COURSE TYPE OF APPROACH WITH THE
TUES/WED SYSTEM GIVEN HOW IT EVOLVES. ESSENTIALLY IT IS DRIVEN BY A
SHORTWAVE EJECTING OUT OF THE SOUTHWEST U.S. UPPER TROUGH. THESE
TYPE OF SYSTEMS ARE FICKLE AND TOUGH TO NAIL DOWN DETAILS ON
ESPECIALLY AT RANGE IN THE FORECAST.

AT THIS POINT FORECAST IS FOR LIGHT SNOW...LOW CHANCES...DEVELOPING
MONDAY NIGHT. ON TUESDAY A SNOW...SLEET...FREEZING RAIN MIX CHANGING
TO FREEZING RAIN AND RAIN. BOTH THE GFS AND ECMWF SHOW A SURGE OF
WARMER AIR INTO THE CWA...THE EURO IS JUST SLOWER WITH IT. MY
INTUITION TELLS ME TO GO WITH THE SLOWER EURO GIVEN A DIGGING TROUGH
DOWN THE WEST COAST. SLOWER IS USUALLY THE WAY TO GO GIVEN THIS
PATTERN. MIX OF RAIN AND SNOW TUESDAY NIGHT CHANGING BACK TO SNOW ON
WEDNESDAY. BOTTOM LINE WE HAVE A WAYS TO GO YET IN DETERMINING THE
FINE DETAILS WITH THIS SYSTEM. BIGGEST IMPACT IN OUR AREA LOOKS TO
BE THE FREEZING PRECIPITATION AS THE HEAVIER SNOW SWATH LAYS DOWN
ACROSS NORTHERN LOWER. STAY TUNED FOR FURTHER MODEL ADJUSTMENTS
THOUGH.

COLDER AIR SWEEPS IN BEHIND THE SYSTEM FOR THURSDAY WITH LAKE SNOWS
LIKELY.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 709 AM EST FRI FEB 27 2015

WINDS ARE TURNING ON SHORE THIS MORNING AND CLOUDS THAT HAVE BEEN
OUT OVER THE LAKE WILL PUSH INLAND THROUGH THE TAF SITES TODAY.
THERE WILL BE A FEW FLURRIES TOWARDS LAKE MICHIGAN AS WELL.
SCT-BKN CLOUDS WITH BASES OF 3500-5000FT CAN BE EXPECTED. WINDS
FROM THE WEST-SOUTHWEST AT 8-12 KNOTS SHOULD DEVELOP TOWARDS
MIDDAY AND CONTINUE THROUGH THE AFTERNOON.

THE CLOUDS SHOULD SCATTER OUT TONIGHT IN MOST LOCATIONS...BUT MAY
CONTINUE BROKEN THROUGH THE NIGHT AT KMKG.

THERE ARE HINTS IN MODEL DATA THAT THE CEILINGS THIS AFTERNOON AND
OVERNIGHT MAY DIP INTO THE MVFR CATEGORY BETWEEN 2000-3000FT. DID
NOT INCLUDE MVFR CIGS IN THE TAFS AT THIS POINT.


&&

.HYDROLOGY...
ISSUED AT 1202 PM EST FRI FEB 27 2015

THE BATTLE CREEK SITE (BTCM4) ON THE KALAMAZOO RIVER HAS SHOWN
SOME ERRONEOUS DATA THROUGH THE MORNING HOURS. THIS HAS BEEN
DETERMINED TO BE CAUSED BY THE EXTREME COLD THAT SETTLED IN
OVERNIGHT. IT HAS SINCE SHOWN SIGNS OF RETURNING BACK TO ITS
ORIGINAL READING AS A RESULT OF THE SUNSHINE THIS AFTERNOON.
COORDINATION WITH LOCAL OFFICIALS HAS NOT REVEALED ANY NEED FOR
CONCERN.

WHILE AREA STREAMS AND RIVERS HAVE BEEN STABLE FOR SEVERAL WEEKS
NOW A RATHER ACTIVE PERIOD AND GRADUAL WARMING TREND IS EXPECTED.
THIS DOES NOT NECESSARILY RAISE ALARM BUT WE SHOULD HEED SPECIFICS
AS TEMPERATURES BEGIN TO INCREASE AND PRECIPITATION APPROACHES.
TOTAL PRECIPITATION THROUGH THE NEXT SEVEN DAYS IS ANTICIPATED TO
REMAIN UNDER AN INCH. THE REAL QUESTION COMES ON TUESDAY...AS TO
THE EXTENT OF WARMTH...PRECIPITATION AMOUNTS AND PRECIPITATION
TYPE. THAT SAID...WE WOULD NEED A MEANINGFUL AMOUNT OF MOISTURE
IN A SHORT PERIOD OF TIME...COUPLED WITH AN EXTENDED PERIOD OF
WARMTH TO CREATE INSTABILITY IN THE CURRENT ICE COVER. AS OF
NOW...NO REAL ISSUES ARE EXPECTED BUT RIVERS WILL BE MONITORED
THROUGH THE NEXT WEEK.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&

$$

UPDATE...WDM
SYNOPSIS...MACZKO
SHORT TERM...MACZKO
LONG TERM...DUKE
AVIATION...DUKE
HYDROLOGY...JAM







000
FXUS63 KGRR 271531
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1031 AM EST FRI FEB 27 2015

LATEST UPDATE...
UPDATE

.SYNOPSIS...
ISSUED AT 320 AM EST FRI FEB 27 2015

CONTINUED COLD THROUGH THE WEEKEND WITH SOME LIGHT SNOW POSSIBLE
NEAR LAKE MICHIGAN TODAY AND MORE WIDESPREAD SNOW EXPECTED SUNDAY
AND SUNDAY NIGHT. A BRIEF WARMUP IS EXPECTED ALONG WITH A MIX OF
RAIN AND SNOW TUESDAY AND TUESDAY NIGHT...BEFORE COLD WEATHER
RETURNS FOR THE REST OF NEXT WEEK.

&&

.UPDATE...
ISSUED AT 1030 AM EST FRI FEB 27 2015

I UPDATED THE FORECAST TO HAVE THE LAKE SNOW BAND AS IT MOVES ON
SHORE BE MORE PERSISTENT. THE LATEST NAM12 SHOWS DECENT LIFT IN
THE DGZ WITH ENOUGH MOISTURE TO KEEP THE SNOW BAND GOING INTO
EARLY THIS AFTERNOON. OTHERWISE THE ON GOING FORECAST LOOKS GREAT.

&&

.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 320 AM EST FRI FEB 27 2015

LITTLE IMPACT WEATHER IN THE SHORT TERM WITH VERY COLD
TEMPERATURES REMAINING AND ONLY SOME LIGHT SNOW POSSIBLE NEAR
LAKE MICHIGAN TODAY. OTHERWISE...MONITORING THE APPROACH OF A
SYSTEM LATE SATURDAY THAT DOES NOT APPEAR TO MOVE THE POSSIBILITY
OF SNOW INTO MICHIGAN UNTIL SUNDAY.

VERY COLD START TO TODAY WITH TEMPERATURES WELL BELOW ZERO AND
SLOW RECOVERY LEADING TO ANOTHER DAY WITH HIGH TEMPERATURES IN
THE 10-20 DEGREE ABOVE ZERO RANGE. SNOW BAND CURRENTLY OVER LAKE
MICHIGAN TO CONTINUE TO SLOWLY WORK INLAND THIS MORNING WEAKENING
AS IT MOVES OVER LAND. A FEW LOCATIONS ALONG THE COAST COULD SEE
A SLOW INCH OR SO THIS MORNING...BUT FOR THE MOST PART JUST A FEW
FLURRIES WEST OF US-131 TODAY AND NO SIGNIFICANT IMPACTS
EXPECTED.

ANOTHER VERY COLD NIGHT AGAIN TONIGHT WITH SOME CLEARING SKIES
BRINGING NEAR ZERO AND BELOW ZERO TEMPERATURES TO LOWER MICHIGAN
AGAIN. SATURDAY AGAIN A COLD DAY WITH INCREASING CLOUDS SATURDAY
NIGHT AHEAD OF AN APPROACHING SYSTEM THAT MAY BRING SOME SNOW TO
THE AREA SUNDAY.

.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 320 AM EST THU FEB 26 2015

FOCUS REMAINS ON TWO EVENTS IN THE LONG TERM...NAMELY SNOW ON SUNDAY
AND THEN THE SYSTEM FOR NEXT WEEK TUESDAY INTO WEDNESDAY.

REGARDING THE SUNDAY SYSTEM IT APPEARS TO HAVE NUDGED A BIT TO THE
SOUTH...AS THE UPPER WAVE DRIVING THE SNOW DIGS INTO THE GREAT LAKES
REGION MORE. THE AXIS OF HEAVIEST PRECIPITATION IS SOLIDLY ACROSS
INDIANA. THE SNOW SPREADS IN LATE SATURDAY NIGHT WITH THE BULK
FALLING DURING THE DAY ON SUNDAY. THE SNOW SHOULD WIND DOWN SUNDAY
EVENING. AMOUNTS MAY BE JUST A TOUCH LOWER THAN WHAT WE WERE
THINKING LAST NIGHT. MAYBE AN INCH OR SO ACROSS CENTRAL LOWER
MI...AND 2-4 INCHES TOWARDS I-94.

A BRIEF LULL IN THE WEATHER FOR SUNDAY NIGHT INTO MONDAY NIGHT
BEFORE FOCUS SHIFTS TO THE NEXT SYSTEM. THE TUESDAY SYSTEM HAS LOST
A BIT OF MODEL TO MODEL CONTINUITY AGAIN WITH THE GFS BEING
QUICKER...DEEPER AND FURTHER NORTH. THE ECMWF IS SLOWER AND
EVENTUALLY NEARS THE SAME DEPTH OF THE GFS. THE CANADIAN DOESN/T
OFFER MUCH OF A LEAN EITHER WAY BEING WEAKER AND SOUTH.

AT THIS POINT TAKING A STAY THE COURSE TYPE OF APPROACH WITH THE
TUES/WED SYSTEM GIVEN HOW IT EVOLVES. ESSENTIALLY IT IS DRIVEN BY A
SHORTWAVE EJECTING OUT OF THE SOUTHWEST U.S. UPPER TROUGH. THESE
TYPE OF SYSTEMS ARE FICKLE AND TOUGH TO NAIL DOWN DETAILS ON
ESPECIALLY AT RANGE IN THE FORECAST.

AT THIS POINT FORECAST IS FOR LIGHT SNOW...LOW CHANCES...DEVELOPING
MONDAY NIGHT. ON TUESDAY A SNOW...SLEET...FREEZING RAIN MIX CHANGING
TO FREEZING RAIN AND RAIN. BOTH THE GFS AND ECMWF SHOW A SURGE OF
WARMER AIR INTO THE CWA...THE EURO IS JUST SLOWER WITH IT. MY
INTUITION TELLS ME TO GO WITH THE SLOWER EURO GIVEN A DIGGING TROUGH
DOWN THE WEST COAST. SLOWER IS USUALLY THE WAY TO GO GIVEN THIS
PATTERN. MIX OF RAIN AND SNOW TUESDAY NIGHT CHANGING BACK TO SNOW ON
WEDNESDAY. BOTTOM LINE WE HAVE A WAYS TO GO YET IN DETERMINING THE
FINE DETAILS WITH THIS SYSTEM. BIGGEST IMPACT IN OUR AREA LOOKS TO
BE THE FREEZING PRECIPITATION AS THE HEAVIER SNOW SWATH LAYS DOWN
ACROSS NORTHERN LOWER. STAY TUNED FOR FURTHER MODEL ADJUSTMENTS
THOUGH.

COLDER AIR SWEEPS IN BEHIND THE SYSTEM FOR THURSDAY WITH LAKE SNOWS
LIKELY.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 709 AM EST FRI FEB 27 2015

WINDS ARE TURNING ON SHORE THIS MORNING AND CLOUDS THAT HAVE BEEN
OUT OVER THE LAKE WILL PUSH INLAND THROUGH THE TAF SITES TODAY.
THERE WILL BE A FEW FLURRIES TOWARDS LAKE MICHIGAN AS WELL.
SCT-BKN CLOUDS WITH BASES OF 3500-5000FT CAN BE EXPECTED. WINDS
FROM THE WEST-SOUTHWEST AT 8-12 KNOTS SHOULD DEVELOP TOWARDS
MIDDAY AND CONTINUE THROUGH THE AFTERNOON.

THE CLOUDS SHOULD SCATTER OUT TONIGHT IN MOST LOCATIONS...BUT MAY
CONTINUE BROKEN THROUGH THE NIGHT AT KMKG.

THERE ARE HINTS IN MODEL DATA THAT THE CEILINGS THIS AFTERNOON AND
OVERNIGHT MAY DIP INTO THE MVFR CATEGORY BETWEEN 2000-3000FT. DID
NOT INCLUDE MVFR CIGS IN THE TAFS AT THIS POINT.


&&

.HYDROLOGY...
ISSUED AT 327 PM EST THU FEB 26 2015

CURRENTLY NO SUSPECTED ICE JAMS OR SIGNIFICANT CHANGES TO RIVER
LEVELS. ICE JAM AND FLOOD THREAT REMAINS LIMITED AT LEAST THROUGH
THE WEEKEND. A SIGNIFICANT WARM-UP OR RAINFALL EVENT WOULD INCREASE
THE POTENTIAL. THE MAGNITUDE OF WARMER AIR AND RAINFALL ACCOMPANYING
THE TUESDAY/WEDNESDAY SYSTEM... AND THUS ITS IMPACT ON RIVERS... IS
UNCERTAIN.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&

$$

UPDATE...WDM
SYNOPSIS...MACZKO
SHORT TERM...MACZKO
LONG TERM...DUKE
AVIATION...DUKE
HYDROLOGY...CAS








000
FXUS63 KGRR 271531
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1031 AM EST FRI FEB 27 2015

LATEST UPDATE...
UPDATE

.SYNOPSIS...
ISSUED AT 320 AM EST FRI FEB 27 2015

CONTINUED COLD THROUGH THE WEEKEND WITH SOME LIGHT SNOW POSSIBLE
NEAR LAKE MICHIGAN TODAY AND MORE WIDESPREAD SNOW EXPECTED SUNDAY
AND SUNDAY NIGHT. A BRIEF WARMUP IS EXPECTED ALONG WITH A MIX OF
RAIN AND SNOW TUESDAY AND TUESDAY NIGHT...BEFORE COLD WEATHER
RETURNS FOR THE REST OF NEXT WEEK.

&&

.UPDATE...
ISSUED AT 1030 AM EST FRI FEB 27 2015

I UPDATED THE FORECAST TO HAVE THE LAKE SNOW BAND AS IT MOVES ON
SHORE BE MORE PERSISTENT. THE LATEST NAM12 SHOWS DECENT LIFT IN
THE DGZ WITH ENOUGH MOISTURE TO KEEP THE SNOW BAND GOING INTO
EARLY THIS AFTERNOON. OTHERWISE THE ON GOING FORECAST LOOKS GREAT.

&&

.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 320 AM EST FRI FEB 27 2015

LITTLE IMPACT WEATHER IN THE SHORT TERM WITH VERY COLD
TEMPERATURES REMAINING AND ONLY SOME LIGHT SNOW POSSIBLE NEAR
LAKE MICHIGAN TODAY. OTHERWISE...MONITORING THE APPROACH OF A
SYSTEM LATE SATURDAY THAT DOES NOT APPEAR TO MOVE THE POSSIBILITY
OF SNOW INTO MICHIGAN UNTIL SUNDAY.

VERY COLD START TO TODAY WITH TEMPERATURES WELL BELOW ZERO AND
SLOW RECOVERY LEADING TO ANOTHER DAY WITH HIGH TEMPERATURES IN
THE 10-20 DEGREE ABOVE ZERO RANGE. SNOW BAND CURRENTLY OVER LAKE
MICHIGAN TO CONTINUE TO SLOWLY WORK INLAND THIS MORNING WEAKENING
AS IT MOVES OVER LAND. A FEW LOCATIONS ALONG THE COAST COULD SEE
A SLOW INCH OR SO THIS MORNING...BUT FOR THE MOST PART JUST A FEW
FLURRIES WEST OF US-131 TODAY AND NO SIGNIFICANT IMPACTS
EXPECTED.

ANOTHER VERY COLD NIGHT AGAIN TONIGHT WITH SOME CLEARING SKIES
BRINGING NEAR ZERO AND BELOW ZERO TEMPERATURES TO LOWER MICHIGAN
AGAIN. SATURDAY AGAIN A COLD DAY WITH INCREASING CLOUDS SATURDAY
NIGHT AHEAD OF AN APPROACHING SYSTEM THAT MAY BRING SOME SNOW TO
THE AREA SUNDAY.

.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 320 AM EST THU FEB 26 2015

FOCUS REMAINS ON TWO EVENTS IN THE LONG TERM...NAMELY SNOW ON SUNDAY
AND THEN THE SYSTEM FOR NEXT WEEK TUESDAY INTO WEDNESDAY.

REGARDING THE SUNDAY SYSTEM IT APPEARS TO HAVE NUDGED A BIT TO THE
SOUTH...AS THE UPPER WAVE DRIVING THE SNOW DIGS INTO THE GREAT LAKES
REGION MORE. THE AXIS OF HEAVIEST PRECIPITATION IS SOLIDLY ACROSS
INDIANA. THE SNOW SPREADS IN LATE SATURDAY NIGHT WITH THE BULK
FALLING DURING THE DAY ON SUNDAY. THE SNOW SHOULD WIND DOWN SUNDAY
EVENING. AMOUNTS MAY BE JUST A TOUCH LOWER THAN WHAT WE WERE
THINKING LAST NIGHT. MAYBE AN INCH OR SO ACROSS CENTRAL LOWER
MI...AND 2-4 INCHES TOWARDS I-94.

A BRIEF LULL IN THE WEATHER FOR SUNDAY NIGHT INTO MONDAY NIGHT
BEFORE FOCUS SHIFTS TO THE NEXT SYSTEM. THE TUESDAY SYSTEM HAS LOST
A BIT OF MODEL TO MODEL CONTINUITY AGAIN WITH THE GFS BEING
QUICKER...DEEPER AND FURTHER NORTH. THE ECMWF IS SLOWER AND
EVENTUALLY NEARS THE SAME DEPTH OF THE GFS. THE CANADIAN DOESN/T
OFFER MUCH OF A LEAN EITHER WAY BEING WEAKER AND SOUTH.

AT THIS POINT TAKING A STAY THE COURSE TYPE OF APPROACH WITH THE
TUES/WED SYSTEM GIVEN HOW IT EVOLVES. ESSENTIALLY IT IS DRIVEN BY A
SHORTWAVE EJECTING OUT OF THE SOUTHWEST U.S. UPPER TROUGH. THESE
TYPE OF SYSTEMS ARE FICKLE AND TOUGH TO NAIL DOWN DETAILS ON
ESPECIALLY AT RANGE IN THE FORECAST.

AT THIS POINT FORECAST IS FOR LIGHT SNOW...LOW CHANCES...DEVELOPING
MONDAY NIGHT. ON TUESDAY A SNOW...SLEET...FREEZING RAIN MIX CHANGING
TO FREEZING RAIN AND RAIN. BOTH THE GFS AND ECMWF SHOW A SURGE OF
WARMER AIR INTO THE CWA...THE EURO IS JUST SLOWER WITH IT. MY
INTUITION TELLS ME TO GO WITH THE SLOWER EURO GIVEN A DIGGING TROUGH
DOWN THE WEST COAST. SLOWER IS USUALLY THE WAY TO GO GIVEN THIS
PATTERN. MIX OF RAIN AND SNOW TUESDAY NIGHT CHANGING BACK TO SNOW ON
WEDNESDAY. BOTTOM LINE WE HAVE A WAYS TO GO YET IN DETERMINING THE
FINE DETAILS WITH THIS SYSTEM. BIGGEST IMPACT IN OUR AREA LOOKS TO
BE THE FREEZING PRECIPITATION AS THE HEAVIER SNOW SWATH LAYS DOWN
ACROSS NORTHERN LOWER. STAY TUNED FOR FURTHER MODEL ADJUSTMENTS
THOUGH.

COLDER AIR SWEEPS IN BEHIND THE SYSTEM FOR THURSDAY WITH LAKE SNOWS
LIKELY.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 709 AM EST FRI FEB 27 2015

WINDS ARE TURNING ON SHORE THIS MORNING AND CLOUDS THAT HAVE BEEN
OUT OVER THE LAKE WILL PUSH INLAND THROUGH THE TAF SITES TODAY.
THERE WILL BE A FEW FLURRIES TOWARDS LAKE MICHIGAN AS WELL.
SCT-BKN CLOUDS WITH BASES OF 3500-5000FT CAN BE EXPECTED. WINDS
FROM THE WEST-SOUTHWEST AT 8-12 KNOTS SHOULD DEVELOP TOWARDS
MIDDAY AND CONTINUE THROUGH THE AFTERNOON.

THE CLOUDS SHOULD SCATTER OUT TONIGHT IN MOST LOCATIONS...BUT MAY
CONTINUE BROKEN THROUGH THE NIGHT AT KMKG.

THERE ARE HINTS IN MODEL DATA THAT THE CEILINGS THIS AFTERNOON AND
OVERNIGHT MAY DIP INTO THE MVFR CATEGORY BETWEEN 2000-3000FT. DID
NOT INCLUDE MVFR CIGS IN THE TAFS AT THIS POINT.


&&

.HYDROLOGY...
ISSUED AT 327 PM EST THU FEB 26 2015

CURRENTLY NO SUSPECTED ICE JAMS OR SIGNIFICANT CHANGES TO RIVER
LEVELS. ICE JAM AND FLOOD THREAT REMAINS LIMITED AT LEAST THROUGH
THE WEEKEND. A SIGNIFICANT WARM-UP OR RAINFALL EVENT WOULD INCREASE
THE POTENTIAL. THE MAGNITUDE OF WARMER AIR AND RAINFALL ACCOMPANYING
THE TUESDAY/WEDNESDAY SYSTEM... AND THUS ITS IMPACT ON RIVERS... IS
UNCERTAIN.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&

$$

UPDATE...WDM
SYNOPSIS...MACZKO
SHORT TERM...MACZKO
LONG TERM...DUKE
AVIATION...DUKE
HYDROLOGY...CAS







000
FXUS63 KGRR 271531
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1031 AM EST FRI FEB 27 2015

LATEST UPDATE...
UPDATE

.SYNOPSIS...
ISSUED AT 320 AM EST FRI FEB 27 2015

CONTINUED COLD THROUGH THE WEEKEND WITH SOME LIGHT SNOW POSSIBLE
NEAR LAKE MICHIGAN TODAY AND MORE WIDESPREAD SNOW EXPECTED SUNDAY
AND SUNDAY NIGHT. A BRIEF WARMUP IS EXPECTED ALONG WITH A MIX OF
RAIN AND SNOW TUESDAY AND TUESDAY NIGHT...BEFORE COLD WEATHER
RETURNS FOR THE REST OF NEXT WEEK.

&&

.UPDATE...
ISSUED AT 1030 AM EST FRI FEB 27 2015

I UPDATED THE FORECAST TO HAVE THE LAKE SNOW BAND AS IT MOVES ON
SHORE BE MORE PERSISTENT. THE LATEST NAM12 SHOWS DECENT LIFT IN
THE DGZ WITH ENOUGH MOISTURE TO KEEP THE SNOW BAND GOING INTO
EARLY THIS AFTERNOON. OTHERWISE THE ON GOING FORECAST LOOKS GREAT.

&&

.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 320 AM EST FRI FEB 27 2015

LITTLE IMPACT WEATHER IN THE SHORT TERM WITH VERY COLD
TEMPERATURES REMAINING AND ONLY SOME LIGHT SNOW POSSIBLE NEAR
LAKE MICHIGAN TODAY. OTHERWISE...MONITORING THE APPROACH OF A
SYSTEM LATE SATURDAY THAT DOES NOT APPEAR TO MOVE THE POSSIBILITY
OF SNOW INTO MICHIGAN UNTIL SUNDAY.

VERY COLD START TO TODAY WITH TEMPERATURES WELL BELOW ZERO AND
SLOW RECOVERY LEADING TO ANOTHER DAY WITH HIGH TEMPERATURES IN
THE 10-20 DEGREE ABOVE ZERO RANGE. SNOW BAND CURRENTLY OVER LAKE
MICHIGAN TO CONTINUE TO SLOWLY WORK INLAND THIS MORNING WEAKENING
AS IT MOVES OVER LAND. A FEW LOCATIONS ALONG THE COAST COULD SEE
A SLOW INCH OR SO THIS MORNING...BUT FOR THE MOST PART JUST A FEW
FLURRIES WEST OF US-131 TODAY AND NO SIGNIFICANT IMPACTS
EXPECTED.

ANOTHER VERY COLD NIGHT AGAIN TONIGHT WITH SOME CLEARING SKIES
BRINGING NEAR ZERO AND BELOW ZERO TEMPERATURES TO LOWER MICHIGAN
AGAIN. SATURDAY AGAIN A COLD DAY WITH INCREASING CLOUDS SATURDAY
NIGHT AHEAD OF AN APPROACHING SYSTEM THAT MAY BRING SOME SNOW TO
THE AREA SUNDAY.

.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 320 AM EST THU FEB 26 2015

FOCUS REMAINS ON TWO EVENTS IN THE LONG TERM...NAMELY SNOW ON SUNDAY
AND THEN THE SYSTEM FOR NEXT WEEK TUESDAY INTO WEDNESDAY.

REGARDING THE SUNDAY SYSTEM IT APPEARS TO HAVE NUDGED A BIT TO THE
SOUTH...AS THE UPPER WAVE DRIVING THE SNOW DIGS INTO THE GREAT LAKES
REGION MORE. THE AXIS OF HEAVIEST PRECIPITATION IS SOLIDLY ACROSS
INDIANA. THE SNOW SPREADS IN LATE SATURDAY NIGHT WITH THE BULK
FALLING DURING THE DAY ON SUNDAY. THE SNOW SHOULD WIND DOWN SUNDAY
EVENING. AMOUNTS MAY BE JUST A TOUCH LOWER THAN WHAT WE WERE
THINKING LAST NIGHT. MAYBE AN INCH OR SO ACROSS CENTRAL LOWER
MI...AND 2-4 INCHES TOWARDS I-94.

A BRIEF LULL IN THE WEATHER FOR SUNDAY NIGHT INTO MONDAY NIGHT
BEFORE FOCUS SHIFTS TO THE NEXT SYSTEM. THE TUESDAY SYSTEM HAS LOST
A BIT OF MODEL TO MODEL CONTINUITY AGAIN WITH THE GFS BEING
QUICKER...DEEPER AND FURTHER NORTH. THE ECMWF IS SLOWER AND
EVENTUALLY NEARS THE SAME DEPTH OF THE GFS. THE CANADIAN DOESN/T
OFFER MUCH OF A LEAN EITHER WAY BEING WEAKER AND SOUTH.

AT THIS POINT TAKING A STAY THE COURSE TYPE OF APPROACH WITH THE
TUES/WED SYSTEM GIVEN HOW IT EVOLVES. ESSENTIALLY IT IS DRIVEN BY A
SHORTWAVE EJECTING OUT OF THE SOUTHWEST U.S. UPPER TROUGH. THESE
TYPE OF SYSTEMS ARE FICKLE AND TOUGH TO NAIL DOWN DETAILS ON
ESPECIALLY AT RANGE IN THE FORECAST.

AT THIS POINT FORECAST IS FOR LIGHT SNOW...LOW CHANCES...DEVELOPING
MONDAY NIGHT. ON TUESDAY A SNOW...SLEET...FREEZING RAIN MIX CHANGING
TO FREEZING RAIN AND RAIN. BOTH THE GFS AND ECMWF SHOW A SURGE OF
WARMER AIR INTO THE CWA...THE EURO IS JUST SLOWER WITH IT. MY
INTUITION TELLS ME TO GO WITH THE SLOWER EURO GIVEN A DIGGING TROUGH
DOWN THE WEST COAST. SLOWER IS USUALLY THE WAY TO GO GIVEN THIS
PATTERN. MIX OF RAIN AND SNOW TUESDAY NIGHT CHANGING BACK TO SNOW ON
WEDNESDAY. BOTTOM LINE WE HAVE A WAYS TO GO YET IN DETERMINING THE
FINE DETAILS WITH THIS SYSTEM. BIGGEST IMPACT IN OUR AREA LOOKS TO
BE THE FREEZING PRECIPITATION AS THE HEAVIER SNOW SWATH LAYS DOWN
ACROSS NORTHERN LOWER. STAY TUNED FOR FURTHER MODEL ADJUSTMENTS
THOUGH.

COLDER AIR SWEEPS IN BEHIND THE SYSTEM FOR THURSDAY WITH LAKE SNOWS
LIKELY.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 709 AM EST FRI FEB 27 2015

WINDS ARE TURNING ON SHORE THIS MORNING AND CLOUDS THAT HAVE BEEN
OUT OVER THE LAKE WILL PUSH INLAND THROUGH THE TAF SITES TODAY.
THERE WILL BE A FEW FLURRIES TOWARDS LAKE MICHIGAN AS WELL.
SCT-BKN CLOUDS WITH BASES OF 3500-5000FT CAN BE EXPECTED. WINDS
FROM THE WEST-SOUTHWEST AT 8-12 KNOTS SHOULD DEVELOP TOWARDS
MIDDAY AND CONTINUE THROUGH THE AFTERNOON.

THE CLOUDS SHOULD SCATTER OUT TONIGHT IN MOST LOCATIONS...BUT MAY
CONTINUE BROKEN THROUGH THE NIGHT AT KMKG.

THERE ARE HINTS IN MODEL DATA THAT THE CEILINGS THIS AFTERNOON AND
OVERNIGHT MAY DIP INTO THE MVFR CATEGORY BETWEEN 2000-3000FT. DID
NOT INCLUDE MVFR CIGS IN THE TAFS AT THIS POINT.


&&

.HYDROLOGY...
ISSUED AT 327 PM EST THU FEB 26 2015

CURRENTLY NO SUSPECTED ICE JAMS OR SIGNIFICANT CHANGES TO RIVER
LEVELS. ICE JAM AND FLOOD THREAT REMAINS LIMITED AT LEAST THROUGH
THE WEEKEND. A SIGNIFICANT WARM-UP OR RAINFALL EVENT WOULD INCREASE
THE POTENTIAL. THE MAGNITUDE OF WARMER AIR AND RAINFALL ACCOMPANYING
THE TUESDAY/WEDNESDAY SYSTEM... AND THUS ITS IMPACT ON RIVERS... IS
UNCERTAIN.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&

$$

UPDATE...WDM
SYNOPSIS...MACZKO
SHORT TERM...MACZKO
LONG TERM...DUKE
AVIATION...DUKE
HYDROLOGY...CAS








000
FXUS63 KGRR 271531
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1031 AM EST FRI FEB 27 2015

LATEST UPDATE...
UPDATE

.SYNOPSIS...
ISSUED AT 320 AM EST FRI FEB 27 2015

CONTINUED COLD THROUGH THE WEEKEND WITH SOME LIGHT SNOW POSSIBLE
NEAR LAKE MICHIGAN TODAY AND MORE WIDESPREAD SNOW EXPECTED SUNDAY
AND SUNDAY NIGHT. A BRIEF WARMUP IS EXPECTED ALONG WITH A MIX OF
RAIN AND SNOW TUESDAY AND TUESDAY NIGHT...BEFORE COLD WEATHER
RETURNS FOR THE REST OF NEXT WEEK.

&&

.UPDATE...
ISSUED AT 1030 AM EST FRI FEB 27 2015

I UPDATED THE FORECAST TO HAVE THE LAKE SNOW BAND AS IT MOVES ON
SHORE BE MORE PERSISTENT. THE LATEST NAM12 SHOWS DECENT LIFT IN
THE DGZ WITH ENOUGH MOISTURE TO KEEP THE SNOW BAND GOING INTO
EARLY THIS AFTERNOON. OTHERWISE THE ON GOING FORECAST LOOKS GREAT.

&&

.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 320 AM EST FRI FEB 27 2015

LITTLE IMPACT WEATHER IN THE SHORT TERM WITH VERY COLD
TEMPERATURES REMAINING AND ONLY SOME LIGHT SNOW POSSIBLE NEAR
LAKE MICHIGAN TODAY. OTHERWISE...MONITORING THE APPROACH OF A
SYSTEM LATE SATURDAY THAT DOES NOT APPEAR TO MOVE THE POSSIBILITY
OF SNOW INTO MICHIGAN UNTIL SUNDAY.

VERY COLD START TO TODAY WITH TEMPERATURES WELL BELOW ZERO AND
SLOW RECOVERY LEADING TO ANOTHER DAY WITH HIGH TEMPERATURES IN
THE 10-20 DEGREE ABOVE ZERO RANGE. SNOW BAND CURRENTLY OVER LAKE
MICHIGAN TO CONTINUE TO SLOWLY WORK INLAND THIS MORNING WEAKENING
AS IT MOVES OVER LAND. A FEW LOCATIONS ALONG THE COAST COULD SEE
A SLOW INCH OR SO THIS MORNING...BUT FOR THE MOST PART JUST A FEW
FLURRIES WEST OF US-131 TODAY AND NO SIGNIFICANT IMPACTS
EXPECTED.

ANOTHER VERY COLD NIGHT AGAIN TONIGHT WITH SOME CLEARING SKIES
BRINGING NEAR ZERO AND BELOW ZERO TEMPERATURES TO LOWER MICHIGAN
AGAIN. SATURDAY AGAIN A COLD DAY WITH INCREASING CLOUDS SATURDAY
NIGHT AHEAD OF AN APPROACHING SYSTEM THAT MAY BRING SOME SNOW TO
THE AREA SUNDAY.

.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 320 AM EST THU FEB 26 2015

FOCUS REMAINS ON TWO EVENTS IN THE LONG TERM...NAMELY SNOW ON SUNDAY
AND THEN THE SYSTEM FOR NEXT WEEK TUESDAY INTO WEDNESDAY.

REGARDING THE SUNDAY SYSTEM IT APPEARS TO HAVE NUDGED A BIT TO THE
SOUTH...AS THE UPPER WAVE DRIVING THE SNOW DIGS INTO THE GREAT LAKES
REGION MORE. THE AXIS OF HEAVIEST PRECIPITATION IS SOLIDLY ACROSS
INDIANA. THE SNOW SPREADS IN LATE SATURDAY NIGHT WITH THE BULK
FALLING DURING THE DAY ON SUNDAY. THE SNOW SHOULD WIND DOWN SUNDAY
EVENING. AMOUNTS MAY BE JUST A TOUCH LOWER THAN WHAT WE WERE
THINKING LAST NIGHT. MAYBE AN INCH OR SO ACROSS CENTRAL LOWER
MI...AND 2-4 INCHES TOWARDS I-94.

A BRIEF LULL IN THE WEATHER FOR SUNDAY NIGHT INTO MONDAY NIGHT
BEFORE FOCUS SHIFTS TO THE NEXT SYSTEM. THE TUESDAY SYSTEM HAS LOST
A BIT OF MODEL TO MODEL CONTINUITY AGAIN WITH THE GFS BEING
QUICKER...DEEPER AND FURTHER NORTH. THE ECMWF IS SLOWER AND
EVENTUALLY NEARS THE SAME DEPTH OF THE GFS. THE CANADIAN DOESN/T
OFFER MUCH OF A LEAN EITHER WAY BEING WEAKER AND SOUTH.

AT THIS POINT TAKING A STAY THE COURSE TYPE OF APPROACH WITH THE
TUES/WED SYSTEM GIVEN HOW IT EVOLVES. ESSENTIALLY IT IS DRIVEN BY A
SHORTWAVE EJECTING OUT OF THE SOUTHWEST U.S. UPPER TROUGH. THESE
TYPE OF SYSTEMS ARE FICKLE AND TOUGH TO NAIL DOWN DETAILS ON
ESPECIALLY AT RANGE IN THE FORECAST.

AT THIS POINT FORECAST IS FOR LIGHT SNOW...LOW CHANCES...DEVELOPING
MONDAY NIGHT. ON TUESDAY A SNOW...SLEET...FREEZING RAIN MIX CHANGING
TO FREEZING RAIN AND RAIN. BOTH THE GFS AND ECMWF SHOW A SURGE OF
WARMER AIR INTO THE CWA...THE EURO IS JUST SLOWER WITH IT. MY
INTUITION TELLS ME TO GO WITH THE SLOWER EURO GIVEN A DIGGING TROUGH
DOWN THE WEST COAST. SLOWER IS USUALLY THE WAY TO GO GIVEN THIS
PATTERN. MIX OF RAIN AND SNOW TUESDAY NIGHT CHANGING BACK TO SNOW ON
WEDNESDAY. BOTTOM LINE WE HAVE A WAYS TO GO YET IN DETERMINING THE
FINE DETAILS WITH THIS SYSTEM. BIGGEST IMPACT IN OUR AREA LOOKS TO
BE THE FREEZING PRECIPITATION AS THE HEAVIER SNOW SWATH LAYS DOWN
ACROSS NORTHERN LOWER. STAY TUNED FOR FURTHER MODEL ADJUSTMENTS
THOUGH.

COLDER AIR SWEEPS IN BEHIND THE SYSTEM FOR THURSDAY WITH LAKE SNOWS
LIKELY.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 709 AM EST FRI FEB 27 2015

WINDS ARE TURNING ON SHORE THIS MORNING AND CLOUDS THAT HAVE BEEN
OUT OVER THE LAKE WILL PUSH INLAND THROUGH THE TAF SITES TODAY.
THERE WILL BE A FEW FLURRIES TOWARDS LAKE MICHIGAN AS WELL.
SCT-BKN CLOUDS WITH BASES OF 3500-5000FT CAN BE EXPECTED. WINDS
FROM THE WEST-SOUTHWEST AT 8-12 KNOTS SHOULD DEVELOP TOWARDS
MIDDAY AND CONTINUE THROUGH THE AFTERNOON.

THE CLOUDS SHOULD SCATTER OUT TONIGHT IN MOST LOCATIONS...BUT MAY
CONTINUE BROKEN THROUGH THE NIGHT AT KMKG.

THERE ARE HINTS IN MODEL DATA THAT THE CEILINGS THIS AFTERNOON AND
OVERNIGHT MAY DIP INTO THE MVFR CATEGORY BETWEEN 2000-3000FT. DID
NOT INCLUDE MVFR CIGS IN THE TAFS AT THIS POINT.


&&

.HYDROLOGY...
ISSUED AT 327 PM EST THU FEB 26 2015

CURRENTLY NO SUSPECTED ICE JAMS OR SIGNIFICANT CHANGES TO RIVER
LEVELS. ICE JAM AND FLOOD THREAT REMAINS LIMITED AT LEAST THROUGH
THE WEEKEND. A SIGNIFICANT WARM-UP OR RAINFALL EVENT WOULD INCREASE
THE POTENTIAL. THE MAGNITUDE OF WARMER AIR AND RAINFALL ACCOMPANYING
THE TUESDAY/WEDNESDAY SYSTEM... AND THUS ITS IMPACT ON RIVERS... IS
UNCERTAIN.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&

$$

UPDATE...WDM
SYNOPSIS...MACZKO
SHORT TERM...MACZKO
LONG TERM...DUKE
AVIATION...DUKE
HYDROLOGY...CAS







000
FXUS63 KGRR 271210
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
710 AM EST FRI FEB 27 2015

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 320 AM EST FRI FEB 27 2015

CONTINUED COLD THROUGH THE WEEKEND WITH SOME LIGHT SNOW POSSIBLE
NEAR LAKE MICHIGAN TODAY AND MORE WIDESPREAD SNOW EXPECTED SUNDAY
AND SUNDAY NIGHT. A BRIEF WARMUP IS EXPECTED ALONG WITH A MIX OF
RAIN AND SNOW TUESDAY AND TUESDAY NIGHT...BEFORE COLD WEATHER
RETURNS FOR THE REST OF NEXT WEEK.

&&

.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 320 AM EST FRI FEB 27 2015

LITTLE IMPACT WEATHER IN THE SHORT TERM WITH VERY COLD
TEMPERATURES REMAINING AND ONLY SOME LIGHT SNOW POSSIBLE NEAR
LAKE MICHIGAN TODAY. OTHERWISE...MONITORING THE APPROACH OF A
SYSTEM LATE SATURDAY THAT DOES NOT APPEAR TO MOVE THE POSSIBILITY
OF SNOW INTO MICHIGAN UNTIL SUNDAY.

VERY COLD START TO TODAY WITH TEMPERATURES WELL BELOW ZERO AND
SLOW RECOVERY LEADING TO ANOTHER DAY WITH HIGH TEMPERATURES IN
THE 10-20 DEGREE ABOVE ZERO RANGE. SNOW BAND CURRENTLY OVER LAKE
MICHIGAN TO CONTINUE TO SLOWLY WORK INLAND THIS MORNING WEAKENING
AS IT MOVES OVER LAND. A FEW LOCATIONS ALONG THE COAST COULD SEE
A SLOW INCH OR SO THIS MORNING...BUT FOR THE MOST PART JUST A FEW
FLURRIES WEST OF US-131 TODAY AND NO SIGNIFICANT IMPACTS
EXPECTED.

ANOTHER VERY COLD NIGHT AGAIN TONIGHT WITH SOME CLEARING SKIES
BRINGING NEAR ZERO AND BELOW ZERO TEMPERATURES TO LOWER MICHIGAN
AGAIN. SATURDAY AGAIN A COLD DAY WITH INCREASING CLOUDS SATURDAY
NIGHT AHEAD OF AN APPROACHING SYSTEM THAT MAY BRING SOME SNOW TO
THE AREA SUNDAY.

.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 320 AM EST THU FEB 26 2015

FOCUS REMAINS ON TWO EVENTS IN THE LONG TERM...NAMELY SNOW ON SUNDAY
AND THEN THE SYSTEM FOR NEXT WEEK TUESDAY INTO WEDNESDAY.

REGARDING THE SUNDAY SYSTEM IT APPEARS TO HAVE NUDGED A BIT TO THE
SOUTH...AS THE UPPER WAVE DRIVING THE SNOW DIGS INTO THE GREAT LAKES
REGION MORE. THE AXIS OF HEAVIEST PRECIPITATION IS SOLIDLY ACROSS
INDIANA. THE SNOW SPREADS IN LATE SATURDAY NIGHT WITH THE BULK
FALLING DURING THE DAY ON SUNDAY. THE SNOW SHOULD WIND DOWN SUNDAY
EVENING. AMOUNTS MAY BE JUST A TOUCH LOWER THAN WHAT WE WERE
THINKING LAST NIGHT. MAYBE AN INCH OR SO ACROSS CENTRAL LOWER
MI...AND 2-4 INCHES TOWARDS I-94.

A BRIEF LULL IN THE WEATHER FOR SUNDAY NIGHT INTO MONDAY NIGHT
BEFORE FOCUS SHIFTS TO THE NEXT SYSTEM. THE TUESDAY SYSTEM HAS LOST
A BIT OF MODEL TO MODEL CONTINUITY AGAIN WITH THE GFS BEING
QUICKER...DEEPER AND FURTHER NORTH. THE ECMWF IS SLOWER AND
EVENTUALLY NEARS THE SAME DEPTH OF THE GFS. THE CANADIAN DOESN/T
OFFER MUCH OF A LEAN EITHER WAY BEING WEAKER AND SOUTH.

AT THIS POINT TAKING A STAY THE COURSE TYPE OF APPROACH WITH THE
TUES/WED SYSTEM GIVEN HOW IT EVOLVES. ESSENTIALLY IT IS DRIVEN BY A
SHORTWAVE EJECTING OUT OF THE SOUTHWEST U.S. UPPER TROUGH. THESE
TYPE OF SYSTEMS ARE FICKLE AND TOUGH TO NAIL DOWN DETAILS ON
ESPECIALLY AT RANGE IN THE FORECAST.

AT THIS POINT FORECAST IS FOR LIGHT SNOW...LOW CHANCES...DEVELOPING
MONDAY NIGHT. ON TUESDAY A SNOW...SLEET...FREEZING RAIN MIX CHANGING
TO FREEZING RAIN AND RAIN. BOTH THE GFS AND ECMWF SHOW A SURGE OF
WARMER AIR INTO THE CWA...THE EURO IS JUST SLOWER WITH IT. MY
INTUITION TELLS ME TO GO WITH THE SLOWER EURO GIVEN A DIGGING TROUGH
DOWN THE WEST COAST. SLOWER IS USUALLY THE WAY TO GO GIVEN THIS
PATTERN. MIX OF RAIN AND SNOW TUESDAY NIGHT CHANGING BACK TO SNOW ON
WEDNESDAY. BOTTOM LINE WE HAVE A WAYS TO GO YET IN DETERMINING THE
FINE DETAILS WITH THIS SYSTEM. BIGGEST IMPACT IN OUR AREA LOOKS TO
BE THE FREEZING PRECIPITATION AS THE HEAVIER SNOW SWATH LAYS DOWN
ACROSS NORTHERN LOWER. STAY TUNED FOR FURTHER MODEL ADJUSTMENTS
THOUGH.

COLDER AIR SWEEPS IN BEHIND THE SYSTEM FOR THURSDAY WITH LAKE SNOWS
LIKELY.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 709 AM EST FRI FEB 27 2015

WINDS ARE TURNING ON SHORE THIS MORNING AND CLOUDS THAT HAVE BEEN
OUT OVER THE LAKE WILL PUSH INLAND THROUGH THE TAF SITES TODAY.
THERE WILL BE A FEW FLURRIES TOWARDS LAKE MICHIGAN AS WELL.
SCT-BKN CLOUDS WITH BASES OF 3500-5000FT CAN BE EXPECTED. WINDS
FROM THE WEST-SOUTHWEST AT 8-12 KNOTS SHOULD DEVELOP TOWARDS
MIDDAY AND CONTINUE THROUGH THE AFTERNOON.

THE CLOUDS SHOULD SCATTER OUT TONIGHT IN MOST LOCATIONS...BUT MAY
CONTINUE BROKEN THROUGH THE NIGHT AT KMKG.

THERE ARE HINTS IN MODEL DATA THAT THE CEILINGS THIS AFTERNOON AND
OVERNIGHT MAY DIP INTO THE MVFR CATEGORY BETWEEN 2000-3000FT. DID
NOT INCLUDE MVFR CIGS IN THE TAFS AT THIS POINT.

&&

.HYDROLOGY...
ISSUED AT 327 PM EST THU FEB 26 2015

CURRENTLY NO SUSPECTED ICE JAMS OR SIGNIFICANT CHANGES TO RIVER
LEVELS. ICE JAM AND FLOOD THREAT REMAINS LIMITED AT LEAST THROUGH
THE WEEKEND. A SIGNIFICANT WARM-UP OR RAINFALL EVENT WOULD INCREASE
THE POTENTIAL. THE MAGNITUDE OF WARMER AIR AND RAINFALL ACCOMPANYING
THE TUESDAY/WEDNESDAY SYSTEM... AND THUS ITS IMPACT ON RIVERS... IS
UNCERTAIN.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&

$$

SYNOPSIS...MACZKO
SHORT TERM...MACZKO
LONG TERM...DUKE
AVIATION...DUKE
HYDROLOGY...CAS








000
FXUS63 KGRR 271210
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
710 AM EST FRI FEB 27 2015

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 320 AM EST FRI FEB 27 2015

CONTINUED COLD THROUGH THE WEEKEND WITH SOME LIGHT SNOW POSSIBLE
NEAR LAKE MICHIGAN TODAY AND MORE WIDESPREAD SNOW EXPECTED SUNDAY
AND SUNDAY NIGHT. A BRIEF WARMUP IS EXPECTED ALONG WITH A MIX OF
RAIN AND SNOW TUESDAY AND TUESDAY NIGHT...BEFORE COLD WEATHER
RETURNS FOR THE REST OF NEXT WEEK.

&&

.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 320 AM EST FRI FEB 27 2015

LITTLE IMPACT WEATHER IN THE SHORT TERM WITH VERY COLD
TEMPERATURES REMAINING AND ONLY SOME LIGHT SNOW POSSIBLE NEAR
LAKE MICHIGAN TODAY. OTHERWISE...MONITORING THE APPROACH OF A
SYSTEM LATE SATURDAY THAT DOES NOT APPEAR TO MOVE THE POSSIBILITY
OF SNOW INTO MICHIGAN UNTIL SUNDAY.

VERY COLD START TO TODAY WITH TEMPERATURES WELL BELOW ZERO AND
SLOW RECOVERY LEADING TO ANOTHER DAY WITH HIGH TEMPERATURES IN
THE 10-20 DEGREE ABOVE ZERO RANGE. SNOW BAND CURRENTLY OVER LAKE
MICHIGAN TO CONTINUE TO SLOWLY WORK INLAND THIS MORNING WEAKENING
AS IT MOVES OVER LAND. A FEW LOCATIONS ALONG THE COAST COULD SEE
A SLOW INCH OR SO THIS MORNING...BUT FOR THE MOST PART JUST A FEW
FLURRIES WEST OF US-131 TODAY AND NO SIGNIFICANT IMPACTS
EXPECTED.

ANOTHER VERY COLD NIGHT AGAIN TONIGHT WITH SOME CLEARING SKIES
BRINGING NEAR ZERO AND BELOW ZERO TEMPERATURES TO LOWER MICHIGAN
AGAIN. SATURDAY AGAIN A COLD DAY WITH INCREASING CLOUDS SATURDAY
NIGHT AHEAD OF AN APPROACHING SYSTEM THAT MAY BRING SOME SNOW TO
THE AREA SUNDAY.

.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 320 AM EST THU FEB 26 2015

FOCUS REMAINS ON TWO EVENTS IN THE LONG TERM...NAMELY SNOW ON SUNDAY
AND THEN THE SYSTEM FOR NEXT WEEK TUESDAY INTO WEDNESDAY.

REGARDING THE SUNDAY SYSTEM IT APPEARS TO HAVE NUDGED A BIT TO THE
SOUTH...AS THE UPPER WAVE DRIVING THE SNOW DIGS INTO THE GREAT LAKES
REGION MORE. THE AXIS OF HEAVIEST PRECIPITATION IS SOLIDLY ACROSS
INDIANA. THE SNOW SPREADS IN LATE SATURDAY NIGHT WITH THE BULK
FALLING DURING THE DAY ON SUNDAY. THE SNOW SHOULD WIND DOWN SUNDAY
EVENING. AMOUNTS MAY BE JUST A TOUCH LOWER THAN WHAT WE WERE
THINKING LAST NIGHT. MAYBE AN INCH OR SO ACROSS CENTRAL LOWER
MI...AND 2-4 INCHES TOWARDS I-94.

A BRIEF LULL IN THE WEATHER FOR SUNDAY NIGHT INTO MONDAY NIGHT
BEFORE FOCUS SHIFTS TO THE NEXT SYSTEM. THE TUESDAY SYSTEM HAS LOST
A BIT OF MODEL TO MODEL CONTINUITY AGAIN WITH THE GFS BEING
QUICKER...DEEPER AND FURTHER NORTH. THE ECMWF IS SLOWER AND
EVENTUALLY NEARS THE SAME DEPTH OF THE GFS. THE CANADIAN DOESN/T
OFFER MUCH OF A LEAN EITHER WAY BEING WEAKER AND SOUTH.

AT THIS POINT TAKING A STAY THE COURSE TYPE OF APPROACH WITH THE
TUES/WED SYSTEM GIVEN HOW IT EVOLVES. ESSENTIALLY IT IS DRIVEN BY A
SHORTWAVE EJECTING OUT OF THE SOUTHWEST U.S. UPPER TROUGH. THESE
TYPE OF SYSTEMS ARE FICKLE AND TOUGH TO NAIL DOWN DETAILS ON
ESPECIALLY AT RANGE IN THE FORECAST.

AT THIS POINT FORECAST IS FOR LIGHT SNOW...LOW CHANCES...DEVELOPING
MONDAY NIGHT. ON TUESDAY A SNOW...SLEET...FREEZING RAIN MIX CHANGING
TO FREEZING RAIN AND RAIN. BOTH THE GFS AND ECMWF SHOW A SURGE OF
WARMER AIR INTO THE CWA...THE EURO IS JUST SLOWER WITH IT. MY
INTUITION TELLS ME TO GO WITH THE SLOWER EURO GIVEN A DIGGING TROUGH
DOWN THE WEST COAST. SLOWER IS USUALLY THE WAY TO GO GIVEN THIS
PATTERN. MIX OF RAIN AND SNOW TUESDAY NIGHT CHANGING BACK TO SNOW ON
WEDNESDAY. BOTTOM LINE WE HAVE A WAYS TO GO YET IN DETERMINING THE
FINE DETAILS WITH THIS SYSTEM. BIGGEST IMPACT IN OUR AREA LOOKS TO
BE THE FREEZING PRECIPITATION AS THE HEAVIER SNOW SWATH LAYS DOWN
ACROSS NORTHERN LOWER. STAY TUNED FOR FURTHER MODEL ADJUSTMENTS
THOUGH.

COLDER AIR SWEEPS IN BEHIND THE SYSTEM FOR THURSDAY WITH LAKE SNOWS
LIKELY.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 709 AM EST FRI FEB 27 2015

WINDS ARE TURNING ON SHORE THIS MORNING AND CLOUDS THAT HAVE BEEN
OUT OVER THE LAKE WILL PUSH INLAND THROUGH THE TAF SITES TODAY.
THERE WILL BE A FEW FLURRIES TOWARDS LAKE MICHIGAN AS WELL.
SCT-BKN CLOUDS WITH BASES OF 3500-5000FT CAN BE EXPECTED. WINDS
FROM THE WEST-SOUTHWEST AT 8-12 KNOTS SHOULD DEVELOP TOWARDS
MIDDAY AND CONTINUE THROUGH THE AFTERNOON.

THE CLOUDS SHOULD SCATTER OUT TONIGHT IN MOST LOCATIONS...BUT MAY
CONTINUE BROKEN THROUGH THE NIGHT AT KMKG.

THERE ARE HINTS IN MODEL DATA THAT THE CEILINGS THIS AFTERNOON AND
OVERNIGHT MAY DIP INTO THE MVFR CATEGORY BETWEEN 2000-3000FT. DID
NOT INCLUDE MVFR CIGS IN THE TAFS AT THIS POINT.

&&

.HYDROLOGY...
ISSUED AT 327 PM EST THU FEB 26 2015

CURRENTLY NO SUSPECTED ICE JAMS OR SIGNIFICANT CHANGES TO RIVER
LEVELS. ICE JAM AND FLOOD THREAT REMAINS LIMITED AT LEAST THROUGH
THE WEEKEND. A SIGNIFICANT WARM-UP OR RAINFALL EVENT WOULD INCREASE
THE POTENTIAL. THE MAGNITUDE OF WARMER AIR AND RAINFALL ACCOMPANYING
THE TUESDAY/WEDNESDAY SYSTEM... AND THUS ITS IMPACT ON RIVERS... IS
UNCERTAIN.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&

$$

SYNOPSIS...MACZKO
SHORT TERM...MACZKO
LONG TERM...DUKE
AVIATION...DUKE
HYDROLOGY...CAS







000
FXUS63 KGRR 270820
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
320 AM EST FRI FEB 27 2015

LATEST UPDATE...
SYNOPSIS/SHORT TERM/LONG TERM

.SYNOPSIS...
ISSUED AT 320 AM EST FRI FEB 27 2015

CONTINUED COLD THROUGH THE WEEKEND WITH SOME LIGHT SNOW POSSIBLE
NEAR LAKE MICHIGAN TODAY AND MORE WIDESPREAD SNOW EXPECTED SUNDAY
AND SUNDAY NIGHT. A BRIEF WARMUP IS EXPECTED ALONG WITH A MIX OF
RAIN AND SNOW TUESDAY AND TUESDAY NIGHT...BEFORE COLD WEATHER
RETURNS FOR THE REST OF NEXT WEEK.

&&

.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 320 AM EST FRI FEB 27 2015

LITTLE IMPACT WEATHER IN THE SHORT TERM WITH VERY COLD
TEMPERATURES REMAINING AND ONLY SOME LIGHT SNOW POSSIBLE NEAR
LAKE MICHIGAN TODAY. OTHERWISE...MONITORING THE APPROACH OF A
SYSTEM LATE SATURDAY THAT DOES NOT APPEAR TO MOVE THE POSSIBILITY
OF SNOW INTO MICHIGAN UNTIL SUNDAY.

VERY COLD START TO TODAY WITH TEMPERATURES WELL BELOW ZERO AND
SLOW RECOVERY LEADING TO ANOTHER DAY WITH HIGH TEMPERATURES IN
THE 10-20 DEGREE ABOVE ZERO RANGE. SNOW BAND CURRENTLY OVER LAKE
MICHIGAN TO CONTINUE TO SLOWLY WORK INLAND THIS MORNING WEAKENING
AS IT MOVES OVER LAND. A FEW LOCATIONS ALONG THE COAST COULD SEE
A SLOW INCH OR SO THIS MORNING...BUT FOR THE MOST PART JUST A FEW
FLURRIES WEST OF US-131 TODAY AND NO SIGNIFICANT IMPACTS
EXPECTED.

ANOTHER VERY COLD NIGHT AGAIN TONIGHT WITH SOME CLEARING SKIES
BRINGING NEAR ZERO AND BELOW ZERO TEMPERATURES TO LOWER MICHIGAN
AGAIN. SATURDAY AGAIN A COLD DAY WITH INCREASING CLOUDS SATURDAY
NIGHT AHEAD OF AN APPROACHING SYSTEM THAT MAY BRING SOME SNOW TO
THE AREA SUNDAY.

.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 320 AM EST THU FEB 26 2015

FOCUS REMAINS ON TWO EVENTS IN THE LONG TERM...NAMELY SNOW ON SUNDAY
AND THEN THE SYSTEM FOR NEXT WEEK TUESDAY INTO WEDNESDAY.

REGARDING THE SUNDAY SYSTEM IT APPEARS TO HAVE NUDGED A BIT TO THE
SOUTH...AS THE UPPER WAVE DRIVING THE SNOW DIGS INTO THE GREAT LAKES
REGION MORE. THE AXIS OF HEAVIEST PRECIPITATION IS SOLIDLY ACROSS
INDIANA. THE SNOW SPREADS IN LATE SATURDAY NIGHT WITH THE BULK
FALLING DURING THE DAY ON SUNDAY. THE SNOW SHOULD WIND DOWN SUNDAY
EVENING. AMOUNTS MAY BE JUST A TOUCH LOWER THAN WHAT WE WERE
THINKING LAST NIGHT. MAYBE AN INCH OR SO ACROSS CENTRAL LOWER
MI...AND 2-4 INCHES TOWARDS I-94.

A BRIEF LULL IN THE WEATHER FOR SUNDAY NIGHT INTO MONDAY NIGHT
BEFORE FOCUS SHIFTS TO THE NEXT SYSTEM. THE TUESDAY SYSTEM HAS LOST
A BIT OF MODEL TO MODEL CONTINUITY AGAIN WITH THE GFS BEING
QUICKER...DEEPER AND FURTHER NORTH. THE ECMWF IS SLOWER AND
EVENTUALLY NEARS THE SAME DEPTH OF THE GFS. THE CANADIAN DOESN/T
OFFER MUCH OF A LEAN EITHER WAY BEING WEAKER AND SOUTH.

AT THIS POINT TAKING A STAY THE COURSE TYPE OF APPROACH WITH THE
TUES/WED SYSTEM GIVEN HOW IT EVOLVES. ESSENTIALLY IT IS DRIVEN BY A
SHORTWAVE EJECTING OUT OF THE SOUTHWEST U.S. UPPER TROUGH. THESE
TYPE OF SYSTEMS ARE FICKLE AND TOUGH TO NAIL DOWN DETAILS ON
ESPECIALLY AT RANGE IN THE FORECAST.

AT THIS POINT FORECAST IS FOR LIGHT SNOW...LOW CHANCES...DEVELOPING
MONDAY NIGHT. ON TUESDAY A SNOW...SLEET...FREEZING RAIN MIX CHANGING
TO FREEZING RAIN AND RAIN. BOTH THE GFS AND ECMWF SHOW A SURGE OF
WARMER AIR INTO THE CWA...THE EURO IS JUST SLOWER WITH IT. MY
INTUITION TELLS ME TO GO WITH THE SLOWER EURO GIVEN A DIGGING TROUGH
DOWN THE WEST COAST. SLOWER IS USUALLY THE WAY TO GO GIVEN THIS
PATTERN. MIX OF RAIN AND SNOW TUESDAY NIGHT CHANGING BACK TO SNOW ON
WEDNESDAY. BOTTOM LINE WE HAVE A WAYS TO GO YET IN DETERMINING THE
FINE DETAILS WITH THIS SYSTEM. BIGGEST IMPACT IN OUR AREA LOOKS TO
BE THE FREEZING PRECIPITATION AS THE HEAVIER SNOW SWATH LAYS DOWN
ACROSS NORTHERN LOWER. STAY TUNED FOR FURTHER MODEL ADJUSTMENTS
THOUGH.

COLDER AIR SWEEPS IN BEHIND THE SYSTEM FOR THURSDAY WITH LAKE SNOWS
LIKELY.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 1151 PM EST THU FEB 26 2015

VFR CONDITIONS EXPECTED THROUGH FRIDAY MORNING. SOME LAKE EFFECT
SNOW SHOWERS WILL MOVE ONSHORE FRIDAY MORNING WITH AREAS OF MVFR
POSSIBLE AT MKG. WINDS WILL BE LIGHT AND VARIABLE OVERNIGHT THEN GO
WEST AROUND 10 KNOTS BY FRIDAY AFTERNOON.

&&

.HYDROLOGY...
ISSUED AT 327 PM EST THU FEB 26 2015

CURRENTLY NO SUSPECTED ICE JAMS OR SIGNIFICANT CHANGES TO RIVER
LEVELS. ICE JAM AND FLOOD THREAT REMAINS LIMITED AT LEAST THROUGH
THE WEEKEND. A SIGNIFICANT WARM-UP OR RAINFALL EVENT WOULD INCREASE
THE POTENTIAL. THE MAGNITUDE OF WARMER AIR AND RAINFALL ACCOMPANYING
THE TUESDAY/WEDNESDAY SYSTEM... AND THUS ITS IMPACT ON RIVERS... IS
UNCERTAIN.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&

$$

SYNOPSIS...MACZKO
SHORT TERM...MACZKO
LONG TERM...DUKE
AVIATION...OSTUNO
HYDROLOGY...CAS







000
FXUS63 KGRR 270820
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
320 AM EST FRI FEB 27 2015

LATEST UPDATE...
SYNOPSIS/SHORT TERM/LONG TERM

.SYNOPSIS...
ISSUED AT 320 AM EST FRI FEB 27 2015

CONTINUED COLD THROUGH THE WEEKEND WITH SOME LIGHT SNOW POSSIBLE
NEAR LAKE MICHIGAN TODAY AND MORE WIDESPREAD SNOW EXPECTED SUNDAY
AND SUNDAY NIGHT. A BRIEF WARMUP IS EXPECTED ALONG WITH A MIX OF
RAIN AND SNOW TUESDAY AND TUESDAY NIGHT...BEFORE COLD WEATHER
RETURNS FOR THE REST OF NEXT WEEK.

&&

.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 320 AM EST FRI FEB 27 2015

LITTLE IMPACT WEATHER IN THE SHORT TERM WITH VERY COLD
TEMPERATURES REMAINING AND ONLY SOME LIGHT SNOW POSSIBLE NEAR
LAKE MICHIGAN TODAY. OTHERWISE...MONITORING THE APPROACH OF A
SYSTEM LATE SATURDAY THAT DOES NOT APPEAR TO MOVE THE POSSIBILITY
OF SNOW INTO MICHIGAN UNTIL SUNDAY.

VERY COLD START TO TODAY WITH TEMPERATURES WELL BELOW ZERO AND
SLOW RECOVERY LEADING TO ANOTHER DAY WITH HIGH TEMPERATURES IN
THE 10-20 DEGREE ABOVE ZERO RANGE. SNOW BAND CURRENTLY OVER LAKE
MICHIGAN TO CONTINUE TO SLOWLY WORK INLAND THIS MORNING WEAKENING
AS IT MOVES OVER LAND. A FEW LOCATIONS ALONG THE COAST COULD SEE
A SLOW INCH OR SO THIS MORNING...BUT FOR THE MOST PART JUST A FEW
FLURRIES WEST OF US-131 TODAY AND NO SIGNIFICANT IMPACTS
EXPECTED.

ANOTHER VERY COLD NIGHT AGAIN TONIGHT WITH SOME CLEARING SKIES
BRINGING NEAR ZERO AND BELOW ZERO TEMPERATURES TO LOWER MICHIGAN
AGAIN. SATURDAY AGAIN A COLD DAY WITH INCREASING CLOUDS SATURDAY
NIGHT AHEAD OF AN APPROACHING SYSTEM THAT MAY BRING SOME SNOW TO
THE AREA SUNDAY.

.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 320 AM EST THU FEB 26 2015

FOCUS REMAINS ON TWO EVENTS IN THE LONG TERM...NAMELY SNOW ON SUNDAY
AND THEN THE SYSTEM FOR NEXT WEEK TUESDAY INTO WEDNESDAY.

REGARDING THE SUNDAY SYSTEM IT APPEARS TO HAVE NUDGED A BIT TO THE
SOUTH...AS THE UPPER WAVE DRIVING THE SNOW DIGS INTO THE GREAT LAKES
REGION MORE. THE AXIS OF HEAVIEST PRECIPITATION IS SOLIDLY ACROSS
INDIANA. THE SNOW SPREADS IN LATE SATURDAY NIGHT WITH THE BULK
FALLING DURING THE DAY ON SUNDAY. THE SNOW SHOULD WIND DOWN SUNDAY
EVENING. AMOUNTS MAY BE JUST A TOUCH LOWER THAN WHAT WE WERE
THINKING LAST NIGHT. MAYBE AN INCH OR SO ACROSS CENTRAL LOWER
MI...AND 2-4 INCHES TOWARDS I-94.

A BRIEF LULL IN THE WEATHER FOR SUNDAY NIGHT INTO MONDAY NIGHT
BEFORE FOCUS SHIFTS TO THE NEXT SYSTEM. THE TUESDAY SYSTEM HAS LOST
A BIT OF MODEL TO MODEL CONTINUITY AGAIN WITH THE GFS BEING
QUICKER...DEEPER AND FURTHER NORTH. THE ECMWF IS SLOWER AND
EVENTUALLY NEARS THE SAME DEPTH OF THE GFS. THE CANADIAN DOESN/T
OFFER MUCH OF A LEAN EITHER WAY BEING WEAKER AND SOUTH.

AT THIS POINT TAKING A STAY THE COURSE TYPE OF APPROACH WITH THE
TUES/WED SYSTEM GIVEN HOW IT EVOLVES. ESSENTIALLY IT IS DRIVEN BY A
SHORTWAVE EJECTING OUT OF THE SOUTHWEST U.S. UPPER TROUGH. THESE
TYPE OF SYSTEMS ARE FICKLE AND TOUGH TO NAIL DOWN DETAILS ON
ESPECIALLY AT RANGE IN THE FORECAST.

AT THIS POINT FORECAST IS FOR LIGHT SNOW...LOW CHANCES...DEVELOPING
MONDAY NIGHT. ON TUESDAY A SNOW...SLEET...FREEZING RAIN MIX CHANGING
TO FREEZING RAIN AND RAIN. BOTH THE GFS AND ECMWF SHOW A SURGE OF
WARMER AIR INTO THE CWA...THE EURO IS JUST SLOWER WITH IT. MY
INTUITION TELLS ME TO GO WITH THE SLOWER EURO GIVEN A DIGGING TROUGH
DOWN THE WEST COAST. SLOWER IS USUALLY THE WAY TO GO GIVEN THIS
PATTERN. MIX OF RAIN AND SNOW TUESDAY NIGHT CHANGING BACK TO SNOW ON
WEDNESDAY. BOTTOM LINE WE HAVE A WAYS TO GO YET IN DETERMINING THE
FINE DETAILS WITH THIS SYSTEM. BIGGEST IMPACT IN OUR AREA LOOKS TO
BE THE FREEZING PRECIPITATION AS THE HEAVIER SNOW SWATH LAYS DOWN
ACROSS NORTHERN LOWER. STAY TUNED FOR FURTHER MODEL ADJUSTMENTS
THOUGH.

COLDER AIR SWEEPS IN BEHIND THE SYSTEM FOR THURSDAY WITH LAKE SNOWS
LIKELY.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 1151 PM EST THU FEB 26 2015

VFR CONDITIONS EXPECTED THROUGH FRIDAY MORNING. SOME LAKE EFFECT
SNOW SHOWERS WILL MOVE ONSHORE FRIDAY MORNING WITH AREAS OF MVFR
POSSIBLE AT MKG. WINDS WILL BE LIGHT AND VARIABLE OVERNIGHT THEN GO
WEST AROUND 10 KNOTS BY FRIDAY AFTERNOON.

&&

.HYDROLOGY...
ISSUED AT 327 PM EST THU FEB 26 2015

CURRENTLY NO SUSPECTED ICE JAMS OR SIGNIFICANT CHANGES TO RIVER
LEVELS. ICE JAM AND FLOOD THREAT REMAINS LIMITED AT LEAST THROUGH
THE WEEKEND. A SIGNIFICANT WARM-UP OR RAINFALL EVENT WOULD INCREASE
THE POTENTIAL. THE MAGNITUDE OF WARMER AIR AND RAINFALL ACCOMPANYING
THE TUESDAY/WEDNESDAY SYSTEM... AND THUS ITS IMPACT ON RIVERS... IS
UNCERTAIN.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&

$$

SYNOPSIS...MACZKO
SHORT TERM...MACZKO
LONG TERM...DUKE
AVIATION...OSTUNO
HYDROLOGY...CAS








000
FXUS63 KGRR 270451
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1151 PM EST THU FEB 26 2015

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 327 PM EST THU FEB 26 2015

THE BIG STORY IS THE DRAMATIC WARM UP EXPECTED WITH THE STORM ON
TUESDAY...THIS WILL BE THE FIRST TIME SINCE THE 11TH OF FEBRUARY
WE HAVE SEEN ABOVE FREEZING TEMPERATURES.

MEANWHILE UNTIL THAT HAPPENS WE WILL HAVE TWO MORE VERY COLD
DAYS...LOWS TONIGHT SHOULD BE BELOW ZERO OVER NEARLY ALL OF
SOUTHWEST LOWER MICHIGAN. TOMORROW WILL SEE HIGHS WARM CLOSER TO
20 DEGREES WITH PARTLY CLOUDY SKIES. THERE COULD BE A FEW FLURRIES
NEAR THE LAKE SHORE IN THE MORNING. TOMORROW NIGHT WILL SEE LOW
NEAR ZERO BUT THAT WILL BE THE LAST REALLY COLD NIGHT FOR AT
NEARLY A WEEK.

SNOW IS STILL EXPECTED SUNDAY BUT SNOWFALL SHOULD NOT BE HEAVY...
JUST ENOUGH TO SAY IT SNOWED. THE STORM EXPECTED ON TUESDAY COMES
FROM THE SOUTHERN PLAINS AND WILL HAVE GULF MOISTURE AND WARMER
AIR AS IT TRACKS THROUGH THE NORTHERN GREAT LAKES. THAT WILL PUT
SOUTHWEST MICHIGAN IN THE WARM SECTOR OF THE STORM.

&&

.SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 327 PM
EST THU FEB 26 2015

COLD TEMPERATURES THE NEXT 36 HOURS WILL BE OUR BIGGEST ISSUE IN
THE SHORT TERM. CURRENTLY NEARLY CLEAR SKIES COVER MOST OF CENTRAL
AND NORTHERN LOWER MICHIGAN. I EXPECT SKIES TO BECOME CLEAR OVER
ALL OF THE CWA BY MID EVENING. WITH THE SURFACE RIDGE MOVING OVER
THE AREA TONIGHT WINDS WILL GO CALM MOST LOCATIONS. GIVEN THE SNOW
ON THE GROUND A DEW POINTS NEAR 5 BELOW ZERO... I SEE NO REASON
THE TEMPERATURE WILL NOT FALL BELOW ZERO ALL BUT THE IMMEDIATE
LAKE SHORE TONIGHT. THE LAKE CLOUDS WILL MOVE BACK IN OVER OUR NW
CWA AFTER MIDNIGHT BUT SHOULD NOT SPREAD OVER A SIGNIFICANT AMOUNT OF
THE CWA BEFORE SUNRISE. I WITH LOWS MOSTLY BETWEEN -5 AND
-15...OUR NE CAW COULD SEE A FEW -20S.

AS RESULT OF THAT WE CONSIDERED ISSUING A WIND CHILL ADVISORY.
HOWEVER WE HAVE DECIDED NOT TO GO WITH THE WIND CHILL ADVISORY
TONIGHT SINCE THERE SURFACE WINDS WILL BE NEAR CALM AND LOW
TEMPERATURES WILL ONLY BE CLOSE TO THE THRESHOLD FOR ISSUING A
WIND CHILL ADVISORY.

THE OTHER ISSUE IS THE LAKE EFFECT SNOW BAND CURRENTLY OVER
CENTRAL LAKE MICHIGAN WILL BE MOVING ON SHORE EARLY FRIDAY MORNING
OVER OUR NW CWA AND OVER THE REST OF OUR WESTERN CWA BY LATE
MORNING. HOWEVER AS IT DOES SO IT WILL BE DISSIPATING SINCE THERE
WILL BE A FAIR AMOUNT OF WIND SHEAR WITHIN THE SNOW BAND AS IT
MOVES ON SHORE. IF NOTHING ELSE THERE WILL BE A PERIOD OF
CLOUDINESS AS WHAT REMAINS OF THE LAKE SNOW BAND MOVES INLAND.

ONCE THOSE LOW CLOUDS MIX OUT... I EXPECT PARTLY CLOUDY SKIES AND
SLIGHTLY WARMER TEMPERATURES SATURDAY.

.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY) ISSUED AT 327 PM
EST THU FEB 26 2015

WE CONTINUE TO FOCUS OUR ATTENTION ON THE SYSTEMS EXPECTED TO IMPACT
THE AREA DURING THE SAT NIGHT/SUN TIME FRAME...AND THE LATE MON
NIGHT THROUGH WED MORNING TIME FRAME.

NO REAL CHANGES WITH THE FIRST SYSTEM FOR THE SAT NIGHT/SUN TIME
FRAME. MODEL AGREEMENT HAS IMPROVED WITH REGARD TO THE TIMING. IT
APPEARS THAT THE SNOW WILL BEGIN OVERNIGHT SAT NIGHT AND THE BULK OF
IT WILL END SUN AFTERNOON. WE CONTINUE TO LOOK FOR ACCUMULATIONS OF
UP TO A FEW INCHES...WITH THE HIGHEST AMOUNTS DOWN SOUTH. THIS ALL
RESULTS STILL FROM A DEVELOPING UPPER JET NEAR THE AREA THAT WILL
INTERACT WITH MOISTURE THAT IS GOING TO BE DRAWN NORTH OUT OF THE
GULF.

WE WILL SEE A GENERALLY QUIET PERIOD THEN FROM SUN NIGHT THROUGH
MOST OF MON NIGHT. THERE WILL BE A SMALL CHANCE OF SOME LAKE EFFECT
ACROSS THE WESTERN PORTION OF THE CWA  FOR SUN NIGHT. THIS DOES NOT
LOOK
TO BE SIGNIFICANT AS H850 TEMPS AROUND -12C WILL BE MARGINAL FOR
LAKE EFFECT. THE UPPER TROUGH AND CYCLONIC FLOW ALOFT WILL ONLY
BRUSH BY THE CWFA...SO NOT MUCH SUPPORT ALOFT WITH LOW INVERSION
HEIGHTS.

THE SYSTEM FOR TUE HAS TRENDED A BIT FURTHER NORTH AND A BIT OF
AGREEMENT HAS DEVELOPED IN THE VARIOUS MODELS. THIS WOULD RESULT IN
WARMER AND WETTER PERIOD. THE TRANSITION COULD BE SLOPPY FOR THE
AREA AS WE COULD SEE JUST ABOUT EVERY PCPN TYPE AS THE WARMER AIR
ALOFT WOULD MOVE IN. THE SLOPPY WX DOES NOT LOOK TO OCCUR FOR A LONG
PERIOD AS THE FLOW GOES SRLY FAIRLY QUICKLY WITH THIS SOLUTION. WE
WOULD SEE TEMPS WELL INTO THE 40S AND APPROACH 50 IF IT COMES TO
FRUITION.

WE HAVE BEEN CONSERVATIVE WITH REGARDS TO TEMPS AND THE RAIN MENTION
FOR NOW. THERE IS STILL A LOT OF UNCERTAINTY WITH THIS TUE SYSTEM.
THE TIMING OF THE ENERGY EJECTING FROM THE DEVELOPING WRN TROUGH IS
CRUCIAL AS WILL BE ANY INFLUENCE FROM THE NRN BRANCH. IT IS LOOKING
MORE LIKELY HOWEVER THAT A DEEPER SW FLOW WILL BECOME ESTABLISHED
OVER THE AREA...LEADING TO THE WARMER AND WETTER SOLUTION. WE WILL
CONTINUE TO MONITOR THE LATEST TRENDS.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 1151 PM EST THU FEB 26 2015

VFR CONDITIONS EXPECTED THROUGH FRIDAY MORNING. SOME LAKE EFFECT
SNOW SHOWERS WILL MOVE ONSHORE FRIDAY MORNING WITH AREAS OF MVFR
POSSIBLE AT MKG. WINDS WILL BE LIGHT AND VARIABLE OVERNIGHT THEN GO
WEST AROUND 10 KNOTS BY FRIDAY AFTERNOON.

&&

.HYDROLOGY...
ISSUED AT 327 PM EST THU FEB 26 2015

CURRENTLY NO SUSPECTED ICE JAMS OR SIGNIFICANT CHANGES TO RIVER
LEVELS. ICE JAM AND FLOOD THREAT REMAINS LIMITED AT LEAST THROUGH
THE WEEKEND. A SIGNIFICANT WARM-UP OR RAINFALL EVENT WOULD INCREASE
THE POTENTIAL. THE MAGNITUDE OF WARMER AIR AND RAINFALL ACCOMPANYING
THE TUESDAY/WEDNESDAY SYSTEM... AND THUS ITS IMPACT ON RIVERS... IS
UNCERTAIN.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&

$$

SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...NJJ
AVIATION...OSTUNO
HYDROLOGY...CAS







000
FXUS63 KGRR 270451
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1151 PM EST THU FEB 26 2015

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 327 PM EST THU FEB 26 2015

THE BIG STORY IS THE DRAMATIC WARM UP EXPECTED WITH THE STORM ON
TUESDAY...THIS WILL BE THE FIRST TIME SINCE THE 11TH OF FEBRUARY
WE HAVE SEEN ABOVE FREEZING TEMPERATURES.

MEANWHILE UNTIL THAT HAPPENS WE WILL HAVE TWO MORE VERY COLD
DAYS...LOWS TONIGHT SHOULD BE BELOW ZERO OVER NEARLY ALL OF
SOUTHWEST LOWER MICHIGAN. TOMORROW WILL SEE HIGHS WARM CLOSER TO
20 DEGREES WITH PARTLY CLOUDY SKIES. THERE COULD BE A FEW FLURRIES
NEAR THE LAKE SHORE IN THE MORNING. TOMORROW NIGHT WILL SEE LOW
NEAR ZERO BUT THAT WILL BE THE LAST REALLY COLD NIGHT FOR AT
NEARLY A WEEK.

SNOW IS STILL EXPECTED SUNDAY BUT SNOWFALL SHOULD NOT BE HEAVY...
JUST ENOUGH TO SAY IT SNOWED. THE STORM EXPECTED ON TUESDAY COMES
FROM THE SOUTHERN PLAINS AND WILL HAVE GULF MOISTURE AND WARMER
AIR AS IT TRACKS THROUGH THE NORTHERN GREAT LAKES. THAT WILL PUT
SOUTHWEST MICHIGAN IN THE WARM SECTOR OF THE STORM.

&&

.SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 327 PM
EST THU FEB 26 2015

COLD TEMPERATURES THE NEXT 36 HOURS WILL BE OUR BIGGEST ISSUE IN
THE SHORT TERM. CURRENTLY NEARLY CLEAR SKIES COVER MOST OF CENTRAL
AND NORTHERN LOWER MICHIGAN. I EXPECT SKIES TO BECOME CLEAR OVER
ALL OF THE CWA BY MID EVENING. WITH THE SURFACE RIDGE MOVING OVER
THE AREA TONIGHT WINDS WILL GO CALM MOST LOCATIONS. GIVEN THE SNOW
ON THE GROUND A DEW POINTS NEAR 5 BELOW ZERO... I SEE NO REASON
THE TEMPERATURE WILL NOT FALL BELOW ZERO ALL BUT THE IMMEDIATE
LAKE SHORE TONIGHT. THE LAKE CLOUDS WILL MOVE BACK IN OVER OUR NW
CWA AFTER MIDNIGHT BUT SHOULD NOT SPREAD OVER A SIGNIFICANT AMOUNT OF
THE CWA BEFORE SUNRISE. I WITH LOWS MOSTLY BETWEEN -5 AND
-15...OUR NE CAW COULD SEE A FEW -20S.

AS RESULT OF THAT WE CONSIDERED ISSUING A WIND CHILL ADVISORY.
HOWEVER WE HAVE DECIDED NOT TO GO WITH THE WIND CHILL ADVISORY
TONIGHT SINCE THERE SURFACE WINDS WILL BE NEAR CALM AND LOW
TEMPERATURES WILL ONLY BE CLOSE TO THE THRESHOLD FOR ISSUING A
WIND CHILL ADVISORY.

THE OTHER ISSUE IS THE LAKE EFFECT SNOW BAND CURRENTLY OVER
CENTRAL LAKE MICHIGAN WILL BE MOVING ON SHORE EARLY FRIDAY MORNING
OVER OUR NW CWA AND OVER THE REST OF OUR WESTERN CWA BY LATE
MORNING. HOWEVER AS IT DOES SO IT WILL BE DISSIPATING SINCE THERE
WILL BE A FAIR AMOUNT OF WIND SHEAR WITHIN THE SNOW BAND AS IT
MOVES ON SHORE. IF NOTHING ELSE THERE WILL BE A PERIOD OF
CLOUDINESS AS WHAT REMAINS OF THE LAKE SNOW BAND MOVES INLAND.

ONCE THOSE LOW CLOUDS MIX OUT... I EXPECT PARTLY CLOUDY SKIES AND
SLIGHTLY WARMER TEMPERATURES SATURDAY.

.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY) ISSUED AT 327 PM
EST THU FEB 26 2015

WE CONTINUE TO FOCUS OUR ATTENTION ON THE SYSTEMS EXPECTED TO IMPACT
THE AREA DURING THE SAT NIGHT/SUN TIME FRAME...AND THE LATE MON
NIGHT THROUGH WED MORNING TIME FRAME.

NO REAL CHANGES WITH THE FIRST SYSTEM FOR THE SAT NIGHT/SUN TIME
FRAME. MODEL AGREEMENT HAS IMPROVED WITH REGARD TO THE TIMING. IT
APPEARS THAT THE SNOW WILL BEGIN OVERNIGHT SAT NIGHT AND THE BULK OF
IT WILL END SUN AFTERNOON. WE CONTINUE TO LOOK FOR ACCUMULATIONS OF
UP TO A FEW INCHES...WITH THE HIGHEST AMOUNTS DOWN SOUTH. THIS ALL
RESULTS STILL FROM A DEVELOPING UPPER JET NEAR THE AREA THAT WILL
INTERACT WITH MOISTURE THAT IS GOING TO BE DRAWN NORTH OUT OF THE
GULF.

WE WILL SEE A GENERALLY QUIET PERIOD THEN FROM SUN NIGHT THROUGH
MOST OF MON NIGHT. THERE WILL BE A SMALL CHANCE OF SOME LAKE EFFECT
ACROSS THE WESTERN PORTION OF THE CWA  FOR SUN NIGHT. THIS DOES NOT
LOOK
TO BE SIGNIFICANT AS H850 TEMPS AROUND -12C WILL BE MARGINAL FOR
LAKE EFFECT. THE UPPER TROUGH AND CYCLONIC FLOW ALOFT WILL ONLY
BRUSH BY THE CWFA...SO NOT MUCH SUPPORT ALOFT WITH LOW INVERSION
HEIGHTS.

THE SYSTEM FOR TUE HAS TRENDED A BIT FURTHER NORTH AND A BIT OF
AGREEMENT HAS DEVELOPED IN THE VARIOUS MODELS. THIS WOULD RESULT IN
WARMER AND WETTER PERIOD. THE TRANSITION COULD BE SLOPPY FOR THE
AREA AS WE COULD SEE JUST ABOUT EVERY PCPN TYPE AS THE WARMER AIR
ALOFT WOULD MOVE IN. THE SLOPPY WX DOES NOT LOOK TO OCCUR FOR A LONG
PERIOD AS THE FLOW GOES SRLY FAIRLY QUICKLY WITH THIS SOLUTION. WE
WOULD SEE TEMPS WELL INTO THE 40S AND APPROACH 50 IF IT COMES TO
FRUITION.

WE HAVE BEEN CONSERVATIVE WITH REGARDS TO TEMPS AND THE RAIN MENTION
FOR NOW. THERE IS STILL A LOT OF UNCERTAINTY WITH THIS TUE SYSTEM.
THE TIMING OF THE ENERGY EJECTING FROM THE DEVELOPING WRN TROUGH IS
CRUCIAL AS WILL BE ANY INFLUENCE FROM THE NRN BRANCH. IT IS LOOKING
MORE LIKELY HOWEVER THAT A DEEPER SW FLOW WILL BECOME ESTABLISHED
OVER THE AREA...LEADING TO THE WARMER AND WETTER SOLUTION. WE WILL
CONTINUE TO MONITOR THE LATEST TRENDS.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 1151 PM EST THU FEB 26 2015

VFR CONDITIONS EXPECTED THROUGH FRIDAY MORNING. SOME LAKE EFFECT
SNOW SHOWERS WILL MOVE ONSHORE FRIDAY MORNING WITH AREAS OF MVFR
POSSIBLE AT MKG. WINDS WILL BE LIGHT AND VARIABLE OVERNIGHT THEN GO
WEST AROUND 10 KNOTS BY FRIDAY AFTERNOON.

&&

.HYDROLOGY...
ISSUED AT 327 PM EST THU FEB 26 2015

CURRENTLY NO SUSPECTED ICE JAMS OR SIGNIFICANT CHANGES TO RIVER
LEVELS. ICE JAM AND FLOOD THREAT REMAINS LIMITED AT LEAST THROUGH
THE WEEKEND. A SIGNIFICANT WARM-UP OR RAINFALL EVENT WOULD INCREASE
THE POTENTIAL. THE MAGNITUDE OF WARMER AIR AND RAINFALL ACCOMPANYING
THE TUESDAY/WEDNESDAY SYSTEM... AND THUS ITS IMPACT ON RIVERS... IS
UNCERTAIN.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&

$$

SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...NJJ
AVIATION...OSTUNO
HYDROLOGY...CAS






000
FXUS63 KGRR 262340
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
640 PM EST THU FEB 26 2015

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 327 PM EST THU FEB 26 2015

THE BIG STORY IS THE DRAMATIC WARM UP EXPECTED WITH THE STORM ON
TUESDAY...THIS WILL BE THE FIRST TIME SINCE THE 11TH OF FEBRUARY
WE HAVE SEEN ABOVE FREEZING TEMPERATURES.

MEANWHILE UNTIL THAT HAPPENS WE WILL HAVE TWO MORE VERY COLD
DAYS...LOWS TONIGHT SHOULD BE BELOW ZERO OVER NEARLY ALL OF
SOUTHWEST LOWER MICHIGAN. TOMORROW WILL SEE HIGHS WARM CLOSER TO
20 DEGREES WITH PARTLY CLOUDY SKIES. THERE COULD BE A FEW FLURRIES
NEAR THE LAKE SHORE IN THE MORNING. TOMORROW NIGHT WILL SEE LOW
NEAR ZERO BUT THAT WILL BE THE LAST REALLY COLD NIGHT FOR AT
NEARLY A WEEK.

SNOW IS STILL EXPECTED SUNDAY BUT SNOWFALL SHOULD NOT BE HEAVY...
JUST ENOUGH TO SAY IT SNOWED. THE STORM EXPECTED ON TUESDAY COMES
FROM THE SOUTHERN PLAINS AND WILL HAVE GULF MOISTURE AND WARMER
AIR AS IT TRACKS THROUGH THE NORTHERN GREAT LAKES. THAT WILL PUT
SOUTHWEST MICHIGAN IN THE WARM SECTOR OF THE STORM.

&&

.SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 327 PM
EST THU FEB 26 2015

COLD TEMPERATURES THE NEXT 36 HOURS WILL BE OUR BIGGEST ISSUE IN
THE SHORT TERM. CURRENTLY NEARLY CLEAR SKIES COVER MOST OF CENTRAL
AND NORTHERN LOWER MICHIGAN. I EXPECT SKIES TO BECOME CLEAR OVER
ALL OF THE CWA BY MID EVENING. WITH THE SURFACE RIDGE MOVING OVER
THE AREA TONIGHT WINDS WILL GO CALM MOST LOCATIONS. GIVEN THE SNOW
ON THE GROUND A DEW POINTS NEAR 5 BELOW ZERO... I SEE NO REASON
THE TEMPERATURE WILL NOT FALL BELOW ZERO ALL BUT THE IMMEDIATE
LAKE SHORE TONIGHT. THE LAKE CLOUDS WILL MOVE BACK IN OVER OUR NW
CWA AFTER MIDNIGHT BUT SHOULD NOT SPREAD OVER A SIGNIFICANT AMOUNT OF
THE CWA BEFORE SUNRISE. I WITH LOWS MOSTLY BETWEEN -5 AND
-15...OUR NE CAW COULD SEE A FEW -20S.

AS RESULT OF THAT WE CONSIDERED ISSUING A WIND CHILL ADVISORY.
HOWEVER WE HAVE DECIDED NOT TO GO WITH THE WIND CHILL ADVISORY
TONIGHT SINCE THERE SURFACE WINDS WILL BE NEAR CALM AND LOW
TEMPERATURES WILL ONLY BE CLOSE TO THE THRESHOLD FOR ISSUING A
WIND CHILL ADVISORY.

THE OTHER ISSUE IS THE LAKE EFFECT SNOW BAND CURRENTLY OVER
CENTRAL LAKE MICHIGAN WILL BE MOVING ON SHORE EARLY FRIDAY MORNING
OVER OUR NW CWA AND OVER THE REST OF OUR WESTERN CWA BY LATE
MORNING. HOWEVER AS IT DOES SO IT WILL BE DISSIPATING SINCE THERE
WILL BE A FAIR AMOUNT OF WIND SHEAR WITHIN THE SNOW BAND AS IT
MOVES ON SHORE. IF NOTHING ELSE THERE WILL BE A PERIOD OF
CLOUDINESS AS WHAT REMAINS OF THE LAKE SNOW BAND MOVES INLAND.

ONCE THOSE LOW CLOUDS MIX OUT... I EXPECT PARTLY CLOUDY SKIES AND
SLIGHTLY WARMER TEMPERATURES SATURDAY.

.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY) ISSUED AT 327 PM
EST THU FEB 26 2015

WE CONTINUE TO FOCUS OUR ATTENTION ON THE SYSTEMS EXPECTED TO IMPACT
THE AREA DURING THE SAT NIGHT/SUN TIME FRAME...AND THE LATE MON
NIGHT THROUGH WED MORNING TIME FRAME.

NO REAL CHANGES WITH THE FIRST SYSTEM FOR THE SAT NIGHT/SUN TIME
FRAME. MODEL AGREEMENT HAS IMPROVED WITH REGARD TO THE TIMING. IT
APPEARS THAT THE SNOW WILL BEGIN OVERNIGHT SAT NIGHT AND THE BULK OF
IT WILL END SUN AFTERNOON. WE CONTINUE TO LOOK FOR ACCUMULATIONS OF
UP TO A FEW INCHES...WITH THE HIGHEST AMOUNTS DOWN SOUTH. THIS ALL
RESULTS STILL FROM A DEVELOPING UPPER JET NEAR THE AREA THAT WILL
INTERACT WITH MOISTURE THAT IS GOING TO BE DRAWN NORTH OUT OF THE
GULF.

WE WILL SEE A GENERALLY QUIET PERIOD THEN FROM SUN NIGHT THROUGH
MOST OF MON NIGHT. THERE WILL BE A SMALL CHANCE OF SOME LAKE EFFECT
ACROSS THE WESTERN PORTION OF THE CWA  FOR SUN NIGHT. THIS DOES NOT
LOOK
TO BE SIGNIFICANT AS H850 TEMPS AROUND -12C WILL BE MARGINAL FOR
LAKE EFFECT. THE UPPER TROUGH AND CYCLONIC FLOW ALOFT WILL ONLY
BRUSH BY THE CWFA...SO NOT MUCH SUPPORT ALOFT WITH LOW INVERSION
HEIGHTS.

THE SYSTEM FOR TUE HAS TRENDED A BIT FURTHER NORTH AND A BIT OF
AGREEMENT HAS DEVELOPED IN THE VARIOUS MODELS. THIS WOULD RESULT IN
WARMER AND WETTER PERIOD. THE TRANSITION COULD BE SLOPPY FOR THE
AREA AS WE COULD SEE JUST ABOUT EVERY PCPN TYPE AS THE WARMER AIR
ALOFT WOULD MOVE IN. THE SLOPPY WX DOES NOT LOOK TO OCCUR FOR A LONG
PERIOD AS THE FLOW GOES SRLY FAIRLY QUICKLY WITH THIS SOLUTION. WE
WOULD SEE TEMPS WELL INTO THE 40S AND APPROACH 50 IF IT COMES TO
FRUITION.

WE HAVE BEEN CONSERVATIVE WITH REGARDS TO TEMPS AND THE RAIN MENTION
FOR NOW. THERE IS STILL A LOT OF UNCERTAINTY WITH THIS TUE SYSTEM.
THE TIMING OF THE ENERGY EJECTING FROM THE DEVELOPING WRN TROUGH IS
CRUCIAL AS WILL BE ANY INFLUENCE FROM THE NRN BRANCH. IT IS LOOKING
MORE LIKELY HOWEVER THAT A DEEPER SW FLOW WILL BECOME ESTABLISHED
OVER THE AREA...LEADING TO THE WARMER AND WETTER SOLUTION. WE WILL
CONTINUE TO MONITOR THE LATEST TRENDS.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 640 PM EST THU FEB 26 2015

VFR CONDITIONS EXPECTED THROUGH FRIDAY MORNING. SOME LAKE EFFECT
SNOW SHOWERS WILL MOVE ONSHORE FRIDAY MORNING WITH AREAS OF MVFR AND
ISOLATED IFR POSSIBLE AT MKG ALTHOUGH THIS WAS NOT PUT IN THE
FORECAST YET DUE TO UNCERTAINTY OF THE SNOW SHOWER INTENSITY. WINDS
WILL BY NORTHWEST AROUND 10 KNOTS EARLY THIS EVENING THEN BECOMING
LIGHT AND VARIABLE OVERNIGHT.

&&

.HYDROLOGY...
ISSUED AT 327 PM EST THU FEB 26 2015

CURRENTLY NO SUSPECTED ICE JAMS OR SIGNIFICANT CHANGES TO RIVER
LEVELS. ICE JAM AND FLOOD THREAT REMAINS LIMITED AT LEAST THROUGH
THE WEEKEND. A SIGNIFICANT WARM-UP OR RAINFALL EVENT WOULD INCREASE
THE POTENTIAL. THE MAGNITUDE OF WARMER AIR AND RAINFALL ACCOMPANYING
THE TUESDAY/WEDNESDAY SYSTEM... AND THUS ITS IMPACT ON RIVERS... IS
UNCERTAIN.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&

$$

SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...NJJ
AVIATION...OSTUNO
HYDROLOGY...CAS






000
FXUS63 KGRR 262340
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
640 PM EST THU FEB 26 2015

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 327 PM EST THU FEB 26 2015

THE BIG STORY IS THE DRAMATIC WARM UP EXPECTED WITH THE STORM ON
TUESDAY...THIS WILL BE THE FIRST TIME SINCE THE 11TH OF FEBRUARY
WE HAVE SEEN ABOVE FREEZING TEMPERATURES.

MEANWHILE UNTIL THAT HAPPENS WE WILL HAVE TWO MORE VERY COLD
DAYS...LOWS TONIGHT SHOULD BE BELOW ZERO OVER NEARLY ALL OF
SOUTHWEST LOWER MICHIGAN. TOMORROW WILL SEE HIGHS WARM CLOSER TO
20 DEGREES WITH PARTLY CLOUDY SKIES. THERE COULD BE A FEW FLURRIES
NEAR THE LAKE SHORE IN THE MORNING. TOMORROW NIGHT WILL SEE LOW
NEAR ZERO BUT THAT WILL BE THE LAST REALLY COLD NIGHT FOR AT
NEARLY A WEEK.

SNOW IS STILL EXPECTED SUNDAY BUT SNOWFALL SHOULD NOT BE HEAVY...
JUST ENOUGH TO SAY IT SNOWED. THE STORM EXPECTED ON TUESDAY COMES
FROM THE SOUTHERN PLAINS AND WILL HAVE GULF MOISTURE AND WARMER
AIR AS IT TRACKS THROUGH THE NORTHERN GREAT LAKES. THAT WILL PUT
SOUTHWEST MICHIGAN IN THE WARM SECTOR OF THE STORM.

&&

.SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 327 PM
EST THU FEB 26 2015

COLD TEMPERATURES THE NEXT 36 HOURS WILL BE OUR BIGGEST ISSUE IN
THE SHORT TERM. CURRENTLY NEARLY CLEAR SKIES COVER MOST OF CENTRAL
AND NORTHERN LOWER MICHIGAN. I EXPECT SKIES TO BECOME CLEAR OVER
ALL OF THE CWA BY MID EVENING. WITH THE SURFACE RIDGE MOVING OVER
THE AREA TONIGHT WINDS WILL GO CALM MOST LOCATIONS. GIVEN THE SNOW
ON THE GROUND A DEW POINTS NEAR 5 BELOW ZERO... I SEE NO REASON
THE TEMPERATURE WILL NOT FALL BELOW ZERO ALL BUT THE IMMEDIATE
LAKE SHORE TONIGHT. THE LAKE CLOUDS WILL MOVE BACK IN OVER OUR NW
CWA AFTER MIDNIGHT BUT SHOULD NOT SPREAD OVER A SIGNIFICANT AMOUNT OF
THE CWA BEFORE SUNRISE. I WITH LOWS MOSTLY BETWEEN -5 AND
-15...OUR NE CAW COULD SEE A FEW -20S.

AS RESULT OF THAT WE CONSIDERED ISSUING A WIND CHILL ADVISORY.
HOWEVER WE HAVE DECIDED NOT TO GO WITH THE WIND CHILL ADVISORY
TONIGHT SINCE THERE SURFACE WINDS WILL BE NEAR CALM AND LOW
TEMPERATURES WILL ONLY BE CLOSE TO THE THRESHOLD FOR ISSUING A
WIND CHILL ADVISORY.

THE OTHER ISSUE IS THE LAKE EFFECT SNOW BAND CURRENTLY OVER
CENTRAL LAKE MICHIGAN WILL BE MOVING ON SHORE EARLY FRIDAY MORNING
OVER OUR NW CWA AND OVER THE REST OF OUR WESTERN CWA BY LATE
MORNING. HOWEVER AS IT DOES SO IT WILL BE DISSIPATING SINCE THERE
WILL BE A FAIR AMOUNT OF WIND SHEAR WITHIN THE SNOW BAND AS IT
MOVES ON SHORE. IF NOTHING ELSE THERE WILL BE A PERIOD OF
CLOUDINESS AS WHAT REMAINS OF THE LAKE SNOW BAND MOVES INLAND.

ONCE THOSE LOW CLOUDS MIX OUT... I EXPECT PARTLY CLOUDY SKIES AND
SLIGHTLY WARMER TEMPERATURES SATURDAY.

.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY) ISSUED AT 327 PM
EST THU FEB 26 2015

WE CONTINUE TO FOCUS OUR ATTENTION ON THE SYSTEMS EXPECTED TO IMPACT
THE AREA DURING THE SAT NIGHT/SUN TIME FRAME...AND THE LATE MON
NIGHT THROUGH WED MORNING TIME FRAME.

NO REAL CHANGES WITH THE FIRST SYSTEM FOR THE SAT NIGHT/SUN TIME
FRAME. MODEL AGREEMENT HAS IMPROVED WITH REGARD TO THE TIMING. IT
APPEARS THAT THE SNOW WILL BEGIN OVERNIGHT SAT NIGHT AND THE BULK OF
IT WILL END SUN AFTERNOON. WE CONTINUE TO LOOK FOR ACCUMULATIONS OF
UP TO A FEW INCHES...WITH THE HIGHEST AMOUNTS DOWN SOUTH. THIS ALL
RESULTS STILL FROM A DEVELOPING UPPER JET NEAR THE AREA THAT WILL
INTERACT WITH MOISTURE THAT IS GOING TO BE DRAWN NORTH OUT OF THE
GULF.

WE WILL SEE A GENERALLY QUIET PERIOD THEN FROM SUN NIGHT THROUGH
MOST OF MON NIGHT. THERE WILL BE A SMALL CHANCE OF SOME LAKE EFFECT
ACROSS THE WESTERN PORTION OF THE CWA  FOR SUN NIGHT. THIS DOES NOT
LOOK
TO BE SIGNIFICANT AS H850 TEMPS AROUND -12C WILL BE MARGINAL FOR
LAKE EFFECT. THE UPPER TROUGH AND CYCLONIC FLOW ALOFT WILL ONLY
BRUSH BY THE CWFA...SO NOT MUCH SUPPORT ALOFT WITH LOW INVERSION
HEIGHTS.

THE SYSTEM FOR TUE HAS TRENDED A BIT FURTHER NORTH AND A BIT OF
AGREEMENT HAS DEVELOPED IN THE VARIOUS MODELS. THIS WOULD RESULT IN
WARMER AND WETTER PERIOD. THE TRANSITION COULD BE SLOPPY FOR THE
AREA AS WE COULD SEE JUST ABOUT EVERY PCPN TYPE AS THE WARMER AIR
ALOFT WOULD MOVE IN. THE SLOPPY WX DOES NOT LOOK TO OCCUR FOR A LONG
PERIOD AS THE FLOW GOES SRLY FAIRLY QUICKLY WITH THIS SOLUTION. WE
WOULD SEE TEMPS WELL INTO THE 40S AND APPROACH 50 IF IT COMES TO
FRUITION.

WE HAVE BEEN CONSERVATIVE WITH REGARDS TO TEMPS AND THE RAIN MENTION
FOR NOW. THERE IS STILL A LOT OF UNCERTAINTY WITH THIS TUE SYSTEM.
THE TIMING OF THE ENERGY EJECTING FROM THE DEVELOPING WRN TROUGH IS
CRUCIAL AS WILL BE ANY INFLUENCE FROM THE NRN BRANCH. IT IS LOOKING
MORE LIKELY HOWEVER THAT A DEEPER SW FLOW WILL BECOME ESTABLISHED
OVER THE AREA...LEADING TO THE WARMER AND WETTER SOLUTION. WE WILL
CONTINUE TO MONITOR THE LATEST TRENDS.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 640 PM EST THU FEB 26 2015

VFR CONDITIONS EXPECTED THROUGH FRIDAY MORNING. SOME LAKE EFFECT
SNOW SHOWERS WILL MOVE ONSHORE FRIDAY MORNING WITH AREAS OF MVFR AND
ISOLATED IFR POSSIBLE AT MKG ALTHOUGH THIS WAS NOT PUT IN THE
FORECAST YET DUE TO UNCERTAINTY OF THE SNOW SHOWER INTENSITY. WINDS
WILL BY NORTHWEST AROUND 10 KNOTS EARLY THIS EVENING THEN BECOMING
LIGHT AND VARIABLE OVERNIGHT.

&&

.HYDROLOGY...
ISSUED AT 327 PM EST THU FEB 26 2015

CURRENTLY NO SUSPECTED ICE JAMS OR SIGNIFICANT CHANGES TO RIVER
LEVELS. ICE JAM AND FLOOD THREAT REMAINS LIMITED AT LEAST THROUGH
THE WEEKEND. A SIGNIFICANT WARM-UP OR RAINFALL EVENT WOULD INCREASE
THE POTENTIAL. THE MAGNITUDE OF WARMER AIR AND RAINFALL ACCOMPANYING
THE TUESDAY/WEDNESDAY SYSTEM... AND THUS ITS IMPACT ON RIVERS... IS
UNCERTAIN.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&

$$

SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...NJJ
AVIATION...OSTUNO
HYDROLOGY...CAS







000
FXUS63 KGRR 262028
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
328 PM EST THU FEB 26 2015

LATEST UPDATE...
SYNOPSIS/SHORT TERM/LONG TERM/HYDRO

.SYNOPSIS...
ISSUED AT 327 PM EST THU FEB 26 2015

THE BIG STORY IS THE DRAMATIC WARM UP EXPECTED WITH THE STORM ON
TUESDAY...THIS WILL BE THE FIRST TIME SINCE THE 11TH OF FEBRUARY
WE HAVE SEEN ABOVE FREEZING TEMPERATURES.

MEANWHILE UNTIL THAT HAPPENS WE WILL HAVE TWO MORE VERY COLD
DAYS...LOWS TONIGHT SHOULD BE BELOW ZERO OVER NEARLY ALL OF
SOUTHWEST LOWER MICHIGAN. TOMORROW WILL SEE HIGHS WARM CLOSER TO
20 DEGREES WITH PARTLY CLOUDY SKIES. THERE COULD BE A FEW FLURRIES
NEAR THE LAKE SHORE IN THE MORNING. TOMORROW NIGHT WILL SEE LOW
NEAR ZERO BUT THAT WILL BE THE LAST REALLY COLD NIGHT FOR AT
NEARLY A WEEK.

SNOW IS STILL EXPECTED SUNDAY BUT SNOWFALL SHOULD NOT BE HEAVY...
JUST ENOUGH TO SAY IT SNOWED. THE STORM EXPECTED ON TUESDAY COMES
FROM THE SOUTHERN PLAINS AND WILL HAVE GULF MOISTURE AND WARMER
AIR AS IT TRACKS THROUGH THE NORTHERN GREAT LAKES. THAT WILL PUT
SOUTHWEST MICHIGAN IN THE WARM SECTOR OF THE STORM.

&&

.SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 327 PM
EST THU FEB 26 2015

COLD TEMPERATURES THE NEXT 36 HOURS WILL BE OUR BIGGEST ISSUE IN
THE SHORT TERM. CURRENTLY NEARLY CLEAR SKIES COVER MOST OF CENTRAL
AND NORTHERN LOWER MICHIGAN. I EXPECT SKIES TO BECOME CLEAR OVER
ALL OF THE CWA BY MID EVENING. WITH THE SURFACE RIDGE MOVING OVER
THE AREA TONIGHT WINDS WILL GO CALM MOST LOCATIONS. GIVEN THE SNOW
ON THE GROUND A DEW POINTS NEAR 5 BELOW ZERO... I SEE NO REASON
THE TEMPERATURE WILL NOT FALL BELOW ZERO ALL BUT THE IMMEDIATE
LAKE SHORE TONIGHT. THE LAKE CLOUDS WILL MOVE BACK IN OVER OUR NW
CWA AFTER MIDNIGHT BUT SHOULD NOT SPREAD OVER A SIGNIFICANT AMOUNT OF
THE CWA BEFORE SUNRISE. I WITH LOWS MOSTLY BETWEEN -5 AND
-15...OUR NE CAW COULD SEE A FEW -20S.

AS RESULT OF THAT WE CONSIDERED ISSUING A WIND CHILL ADVISORY.
HOWEVER WE HAVE DECIDED NOT TO GO WITH THE WIND CHILL ADVISORY
TONIGHT SINCE THERE SURFACE WINDS WILL BE NEAR CALM AND LOW
TEMPERATURES WILL ONLY BE CLOSE TO THE THRESHOLD FOR ISSUING A
WIND CHILL ADVISORY.

THE OTHER ISSUE IS THE LAKE EFFECT SNOW BAND CURRENTLY OVER
CENTRAL LAKE MICHIGAN WILL BE MOVING ON SHORE EARLY FRIDAY MORNING
OVER OUR NW CWA AND OVER THE REST OF OUR WESTERN CWA BY LATE
MORNING. HOWEVER AS IT DOES SO IT WILL BE DISSIPATING SINCE THERE
WILL BE A FAIR AMOUNT OF WIND SHEAR WITHIN THE SNOW BAND AS IT
MOVES ON SHORE. IF NOTHING ELSE THERE WILL BE A PERIOD OF
CLOUDINESS AS WHAT REMAINS OF THE LAKE SNOW BAND MOVES INLAND.

ONCE THOSE LOW CLOUDS MIX OUT... I EXPECT PARTLY CLOUDY SKIES AND
SLIGHTLY WARMER TEMPERATURES SATURDAY.

.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY) ISSUED AT 327 PM
EST THU FEB 26 2015

WE CONTINUE TO FOCUS OUR ATTENTION ON THE SYSTEMS EXPECTED TO IMPACT
THE AREA DURING THE SAT NIGHT/SUN TIME FRAME...AND THE LATE MON
NIGHT THROUGH WED MORNING TIME FRAME.

NO REAL CHANGES WITH THE FIRST SYSTEM FOR THE SAT NIGHT/SUN TIME
FRAME. MODEL AGREEMENT HAS IMPROVED WITH REGARD TO THE TIMING. IT
APPEARS THAT THE SNOW WILL BEGIN OVERNIGHT SAT NIGHT AND THE BULK OF
IT WILL END SUN AFTERNOON. WE CONTINUE TO LOOK FOR ACCUMULATIONS OF
UP TO A FEW INCHES...WITH THE HIGHEST AMOUNTS DOWN SOUTH. THIS ALL
RESULTS STILL FROM A DEVELOPING UPPER JET NEAR THE AREA THAT WILL
INTERACT WITH MOISTURE THAT IS GOING TO BE DRAWN NORTH OUT OF THE
GULF.

WE WILL SEE A GENERALLY QUIET PERIOD THEN FROM SUN NIGHT THROUGH
MOST OF MON NIGHT. THERE WILL BE A SMALL CHANCE OF SOME LAKE EFFECT
ACROSS THE WESTERN PORTION OF THE CWA  FOR SUN NIGHT. THIS DOES NOT LOOK
TO BE SIGNIFICANT AS H850 TEMPS AROUND -12C WILL BE MARGINAL FOR
LAKE EFFECT. THE UPPER TROUGH AND CYCLONIC FLOW ALOFT WILL ONLY
BRUSH BY THE CWFA...SO NOT MUCH SUPPORT ALOFT WITH LOW INVERSION
HEIGHTS.

THE SYSTEM FOR TUE HAS TRENDED A BIT FURTHER NORTH AND A BIT OF
AGREEMENT HAS DEVELOPED IN THE VARIOUS MODELS. THIS WOULD RESULT IN
WARMER AND WETTER PERIOD. THE TRANSITION COULD BE SLOPPY FOR THE
AREA AS WE COULD SEE JUST ABOUT EVERY PCPN TYPE AS THE WARMER AIR
ALOFT WOULD MOVE IN. THE SLOPPY WX DOES NOT LOOK TO OCCUR FOR A LONG
PERIOD AS THE FLOW GOES SRLY FAIRLY QUICKLY WITH THIS SOLUTION. WE
WOULD SEE TEMPS WELL INTO THE 40S AND APPROACH 50 IF IT COMES TO
FRUITION.

WE HAVE BEEN CONSERVATIVE WITH REGARDS TO TEMPS AND THE RAIN MENTION
FOR NOW. THERE IS STILL A LOT OF UNCERTAINTY WITH THIS TUE SYSTEM.
THE TIMING OF THE ENERGY EJECTING FROM THE DEVELOPING WRN TROUGH IS
CRUCIAL AS WILL BE ANY INFLUENCE FROM THE NRN BRANCH. IT IS LOOKING
MORE LIKELY HOWEVER THAT A DEEPER SW FLOW WILL BECOME ESTABLISHED
OVER THE AREA...LEADING TO THE WARMER AND WETTER SOLUTION. WE WILL
CONTINUE TO MONITOR THE LATEST TRENDS.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1223 PM EST THU FEB 26 2015

THE LIGHT SNOW AND LOWER CONDITIONS THAT WERE IN PLACE THIS
MORNING HAVE BEEN IMPROVING ACROSS THE ENTIRE AREA. JUST ABOUT ALL
SITES HAVE TRENDED VFR AS OF 1730Z...EXCEPT A FEW ISOLATED
MARGINAL MVFR CIGS. WE EXPECT ALL ISOLATED MVFR CONDITIONS TO MOVE
OUT/DISSIPATE BY 19Z THIS AFTERNOON. SKIES SHOULD THEN CLEAR OUT
TOWARD SUNSET AND WINDS WILL GO NEARLY CALM.

WE WILL SEE LAKE EFFECT CLOUD COVER WELL OUT OVER THE LAKE...
EVENTUALLY BEGIN TO MOVE INLAND LATER TONIGHT AND ON FRI MORNING
AS WINDS IN THE CLOUD LAYER EVENTUALLY SHIFT ONSHORE. KMKG WILL
LIKELY SEE THE CLOUDS MOVE IN TOWARD 06Z...AND THEN THE CLOUDS
WILL SPREAD INLAND THEREAFTER. IT LOOKS LIKE TOWARD 12Z FOR KGRR
AND KAZO...AND EVEN LATER FURTHER INLAND. SOME FLURRIES WILL BE
LIKELY...SO WE HAVE INCLUDED A VCSH FOR THE WRN SITES.


&&

.HYDROLOGY...
ISSUED AT 327 PM EST THU FEB 26 2015

CURRENTLY NO SUSPECTED ICE JAMS OR SIGNIFICANT CHANGES TO RIVER
LEVELS. ICE JAM AND FLOOD THREAT REMAINS LIMITED AT LEAST THROUGH
THE WEEKEND. A SIGNIFICANT WARM-UP OR RAINFALL EVENT WOULD INCREASE
THE POTENTIAL. THE MAGNITUDE OF WARMER AIR AND RAINFALL ACCOMPANYING
THE TUESDAY/WEDNESDAY SYSTEM... AND THUS ITS IMPACT ON RIVERS... IS
UNCERTAIN.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&

$$

SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...NJJ
AVIATION...NJJ
HYDROLOGY...CAS








000
FXUS63 KGRR 262028
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
328 PM EST THU FEB 26 2015

LATEST UPDATE...
SYNOPSIS/SHORT TERM/LONG TERM/HYDRO

.SYNOPSIS...
ISSUED AT 327 PM EST THU FEB 26 2015

THE BIG STORY IS THE DRAMATIC WARM UP EXPECTED WITH THE STORM ON
TUESDAY...THIS WILL BE THE FIRST TIME SINCE THE 11TH OF FEBRUARY
WE HAVE SEEN ABOVE FREEZING TEMPERATURES.

MEANWHILE UNTIL THAT HAPPENS WE WILL HAVE TWO MORE VERY COLD
DAYS...LOWS TONIGHT SHOULD BE BELOW ZERO OVER NEARLY ALL OF
SOUTHWEST LOWER MICHIGAN. TOMORROW WILL SEE HIGHS WARM CLOSER TO
20 DEGREES WITH PARTLY CLOUDY SKIES. THERE COULD BE A FEW FLURRIES
NEAR THE LAKE SHORE IN THE MORNING. TOMORROW NIGHT WILL SEE LOW
NEAR ZERO BUT THAT WILL BE THE LAST REALLY COLD NIGHT FOR AT
NEARLY A WEEK.

SNOW IS STILL EXPECTED SUNDAY BUT SNOWFALL SHOULD NOT BE HEAVY...
JUST ENOUGH TO SAY IT SNOWED. THE STORM EXPECTED ON TUESDAY COMES
FROM THE SOUTHERN PLAINS AND WILL HAVE GULF MOISTURE AND WARMER
AIR AS IT TRACKS THROUGH THE NORTHERN GREAT LAKES. THAT WILL PUT
SOUTHWEST MICHIGAN IN THE WARM SECTOR OF THE STORM.

&&

.SHORT TERM...(THIS EVENING THROUGH SATURDAY) ISSUED AT 327 PM
EST THU FEB 26 2015

COLD TEMPERATURES THE NEXT 36 HOURS WILL BE OUR BIGGEST ISSUE IN
THE SHORT TERM. CURRENTLY NEARLY CLEAR SKIES COVER MOST OF CENTRAL
AND NORTHERN LOWER MICHIGAN. I EXPECT SKIES TO BECOME CLEAR OVER
ALL OF THE CWA BY MID EVENING. WITH THE SURFACE RIDGE MOVING OVER
THE AREA TONIGHT WINDS WILL GO CALM MOST LOCATIONS. GIVEN THE SNOW
ON THE GROUND A DEW POINTS NEAR 5 BELOW ZERO... I SEE NO REASON
THE TEMPERATURE WILL NOT FALL BELOW ZERO ALL BUT THE IMMEDIATE
LAKE SHORE TONIGHT. THE LAKE CLOUDS WILL MOVE BACK IN OVER OUR NW
CWA AFTER MIDNIGHT BUT SHOULD NOT SPREAD OVER A SIGNIFICANT AMOUNT OF
THE CWA BEFORE SUNRISE. I WITH LOWS MOSTLY BETWEEN -5 AND
-15...OUR NE CAW COULD SEE A FEW -20S.

AS RESULT OF THAT WE CONSIDERED ISSUING A WIND CHILL ADVISORY.
HOWEVER WE HAVE DECIDED NOT TO GO WITH THE WIND CHILL ADVISORY
TONIGHT SINCE THERE SURFACE WINDS WILL BE NEAR CALM AND LOW
TEMPERATURES WILL ONLY BE CLOSE TO THE THRESHOLD FOR ISSUING A
WIND CHILL ADVISORY.

THE OTHER ISSUE IS THE LAKE EFFECT SNOW BAND CURRENTLY OVER
CENTRAL LAKE MICHIGAN WILL BE MOVING ON SHORE EARLY FRIDAY MORNING
OVER OUR NW CWA AND OVER THE REST OF OUR WESTERN CWA BY LATE
MORNING. HOWEVER AS IT DOES SO IT WILL BE DISSIPATING SINCE THERE
WILL BE A FAIR AMOUNT OF WIND SHEAR WITHIN THE SNOW BAND AS IT
MOVES ON SHORE. IF NOTHING ELSE THERE WILL BE A PERIOD OF
CLOUDINESS AS WHAT REMAINS OF THE LAKE SNOW BAND MOVES INLAND.

ONCE THOSE LOW CLOUDS MIX OUT... I EXPECT PARTLY CLOUDY SKIES AND
SLIGHTLY WARMER TEMPERATURES SATURDAY.

.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY) ISSUED AT 327 PM
EST THU FEB 26 2015

WE CONTINUE TO FOCUS OUR ATTENTION ON THE SYSTEMS EXPECTED TO IMPACT
THE AREA DURING THE SAT NIGHT/SUN TIME FRAME...AND THE LATE MON
NIGHT THROUGH WED MORNING TIME FRAME.

NO REAL CHANGES WITH THE FIRST SYSTEM FOR THE SAT NIGHT/SUN TIME
FRAME. MODEL AGREEMENT HAS IMPROVED WITH REGARD TO THE TIMING. IT
APPEARS THAT THE SNOW WILL BEGIN OVERNIGHT SAT NIGHT AND THE BULK OF
IT WILL END SUN AFTERNOON. WE CONTINUE TO LOOK FOR ACCUMULATIONS OF
UP TO A FEW INCHES...WITH THE HIGHEST AMOUNTS DOWN SOUTH. THIS ALL
RESULTS STILL FROM A DEVELOPING UPPER JET NEAR THE AREA THAT WILL
INTERACT WITH MOISTURE THAT IS GOING TO BE DRAWN NORTH OUT OF THE
GULF.

WE WILL SEE A GENERALLY QUIET PERIOD THEN FROM SUN NIGHT THROUGH
MOST OF MON NIGHT. THERE WILL BE A SMALL CHANCE OF SOME LAKE EFFECT
ACROSS THE WESTERN PORTION OF THE CWA  FOR SUN NIGHT. THIS DOES NOT LOOK
TO BE SIGNIFICANT AS H850 TEMPS AROUND -12C WILL BE MARGINAL FOR
LAKE EFFECT. THE UPPER TROUGH AND CYCLONIC FLOW ALOFT WILL ONLY
BRUSH BY THE CWFA...SO NOT MUCH SUPPORT ALOFT WITH LOW INVERSION
HEIGHTS.

THE SYSTEM FOR TUE HAS TRENDED A BIT FURTHER NORTH AND A BIT OF
AGREEMENT HAS DEVELOPED IN THE VARIOUS MODELS. THIS WOULD RESULT IN
WARMER AND WETTER PERIOD. THE TRANSITION COULD BE SLOPPY FOR THE
AREA AS WE COULD SEE JUST ABOUT EVERY PCPN TYPE AS THE WARMER AIR
ALOFT WOULD MOVE IN. THE SLOPPY WX DOES NOT LOOK TO OCCUR FOR A LONG
PERIOD AS THE FLOW GOES SRLY FAIRLY QUICKLY WITH THIS SOLUTION. WE
WOULD SEE TEMPS WELL INTO THE 40S AND APPROACH 50 IF IT COMES TO
FRUITION.

WE HAVE BEEN CONSERVATIVE WITH REGARDS TO TEMPS AND THE RAIN MENTION
FOR NOW. THERE IS STILL A LOT OF UNCERTAINTY WITH THIS TUE SYSTEM.
THE TIMING OF THE ENERGY EJECTING FROM THE DEVELOPING WRN TROUGH IS
CRUCIAL AS WILL BE ANY INFLUENCE FROM THE NRN BRANCH. IT IS LOOKING
MORE LIKELY HOWEVER THAT A DEEPER SW FLOW WILL BECOME ESTABLISHED
OVER THE AREA...LEADING TO THE WARMER AND WETTER SOLUTION. WE WILL
CONTINUE TO MONITOR THE LATEST TRENDS.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1223 PM EST THU FEB 26 2015

THE LIGHT SNOW AND LOWER CONDITIONS THAT WERE IN PLACE THIS
MORNING HAVE BEEN IMPROVING ACROSS THE ENTIRE AREA. JUST ABOUT ALL
SITES HAVE TRENDED VFR AS OF 1730Z...EXCEPT A FEW ISOLATED
MARGINAL MVFR CIGS. WE EXPECT ALL ISOLATED MVFR CONDITIONS TO MOVE
OUT/DISSIPATE BY 19Z THIS AFTERNOON. SKIES SHOULD THEN CLEAR OUT
TOWARD SUNSET AND WINDS WILL GO NEARLY CALM.

WE WILL SEE LAKE EFFECT CLOUD COVER WELL OUT OVER THE LAKE...
EVENTUALLY BEGIN TO MOVE INLAND LATER TONIGHT AND ON FRI MORNING
AS WINDS IN THE CLOUD LAYER EVENTUALLY SHIFT ONSHORE. KMKG WILL
LIKELY SEE THE CLOUDS MOVE IN TOWARD 06Z...AND THEN THE CLOUDS
WILL SPREAD INLAND THEREAFTER. IT LOOKS LIKE TOWARD 12Z FOR KGRR
AND KAZO...AND EVEN LATER FURTHER INLAND. SOME FLURRIES WILL BE
LIKELY...SO WE HAVE INCLUDED A VCSH FOR THE WRN SITES.


&&

.HYDROLOGY...
ISSUED AT 327 PM EST THU FEB 26 2015

CURRENTLY NO SUSPECTED ICE JAMS OR SIGNIFICANT CHANGES TO RIVER
LEVELS. ICE JAM AND FLOOD THREAT REMAINS LIMITED AT LEAST THROUGH
THE WEEKEND. A SIGNIFICANT WARM-UP OR RAINFALL EVENT WOULD INCREASE
THE POTENTIAL. THE MAGNITUDE OF WARMER AIR AND RAINFALL ACCOMPANYING
THE TUESDAY/WEDNESDAY SYSTEM... AND THUS ITS IMPACT ON RIVERS... IS
UNCERTAIN.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&

$$

SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...NJJ
AVIATION...NJJ
HYDROLOGY...CAS







000
FXUS63 KGRR 261723
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1223 PM EST THU FEB 26 2015

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 330 AM EST THU FEB 26 2015

A FEW LIGHT SNOW SHOWERS AND FLURRIES WILL LINGER ACROSS FAR
SOUTHERN LOWER MICHIGAN THIS MORNING BEFORE HIGH PRESSURE BUILDS
IN TO PRODUCE FAIR BUT COLD WEATHER LATER TODAY THROUGH SATURDAY.
TEMPERATURES WILL FINALLY UNDERGO A GRADUAL MODERATING TREND
SUNDAY INTO EARLY NEXT WEEK.

&&

.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 330 AM EST THU FEB 26 2015

KGRR RADAR TRENDS AND A CONSENSUS OF SHORT RANGE GUIDANCE SUGGESTS
THAT A FEW LIGHT SNOW SHOWERS AND FLURRIES WILL LINGER THIS
MORNING MAINLY SOUTH OF I-96 WITH VERY LIGHT ACCUMULATIONS OF
UNDER AN INCH.

HIGH PRESSURE WILL BUILD IN LATER TODAY THROUGH SATURDAY TO
PRODUCE FAIR BUT VERY COLD WX. MAX TEMPS TODAY WILL ONLY REACH THE
UPPER SINGLE DIGITS TO MIDDLE TEENS.

WIDESPREAD SUB ZERO MIN TEMPS ARE ANTICIPATED TONIGHT AS SKIES
CLEAR AND WINDS GO CALM AND WITH EXPANSIVE SNOW COVER IN PLACE
ACROSS OUR AREA.

MAX TEMPS FRIDAY WILL ONLY REACH THE TEENS IN SPITE OF A FAIR
AMOUNT OF SUN AFTER THE VERY COLD START TO THE DAY. IT WILL BE
VERY COLD FRIDAY NIGHT AS WELL BUT NOT QUITE AS COLD AS TONIGHT
WITH MIN TEMPS GENERALLY IN THE FIVE BELOW TO FIVE ABOVE ZERO RANGE.

A CONSENSUS OF 00Z TIME HEIGHT RH PROGS SUGGESTS THERE WILL BE
PLENTY OF SUN ON SATURDAY. HOWEVER MAX TEMPS SATURDAY WILL ONLY
REACH THE UPPER TEENS TO LOWER 20S.

WIND SPEEDS TONIGHT WILL BE CALM TO LESS THAN 5 MPH. APPARENT
TEMP READINGS MAY FLIRT WITH -15 ACROSS OUR NORTHERN COUNTIES
DURING THE EARLY MORNING HOURS FRIDAY. HOWEVER GIVEN VERY LITTLE
TO NO WIND OVERNIGHT WIND CHILL ADVISORY CRITERIA WILL LIKELY NOT
BE ATTAINED.

.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 330 AM EST THU FEB 26 2015

FELT YESTERDAY AFTERNOON/S LONG TERM DISCUSSION HAD A VERY GOOD
DESCRIPTION AND HANDLE ON THE EXTENDED PERIODS. DID NOT DEVIATE MUCH
FROM THAT THINKING AS THERE WERE NO REAL SURPRISES IN THE EVENING
MODEL RUNS.

THERE ARE STILL TWO MAIN SYSTEMS TO FOCUS ON IN THE LONG TERM...THE
SNOW EVENT FOR LATE SATURDAY NIGHT THROUGH SUNDAY EVENING AND THE
SYSTEM CENTERED ON NEXT TUESDAY.

THE SUNDAY SNOW EVENT HAS BEEN VERY STEADY IN REGARD TO TIMING AND
AMOUNTS. SNOW TOTALS RANGE FROM 1-2 INCHES UP TOWARDS U.S. 10...TO
3-6 INCHES TOWARDS I-94. THE SNOW IS GENERATED VIA UPPER LEVEL
DIVERGENCE ASSOCIATED WITH A STRONG JET STREAK...LOW LEVEL
ISENTROPIC RESPONSE AND A WEAK FRONTAL ZONE. MODELS HAVE BEEN
CONSISTENT WITH AMOUNTS FROM RUN TO RUN AND MODEL TO MODEL...SO
CONFIDENCE IN THE SATURDAY NIGHT THROUGH SUNDAY NIGHT SNOW IS FAIRLY
HIGH.

FOCUS THEN SHIFTS TO A LOW THAT DEVELOPS IN THE LEE OF THE ROCKIES
IN SOUTHEAST COLORADO ON MONDAY. THE LOW MOVES NORTHEAST TOWARDS THE
GREAT LAKES AND SHOULD SPREAD SNOW INTO SOUTHWEST LOWER MICHIGAN
LATE MONDAY NIGHT. A MIXTURE OF PRECIPITATION THEN APPEARS POSSIBLE
TUESDAY AND TUESDAY NIGHT AS A GOOD SOUTHERLY FLOW OF MOISTURE AND
WARMTH IS TAPPED. 850MB TEMPERATURES ARE WARM ENOUGH FOR PLAIN RAIN
TUESDAY EVENING ALONG I-94 WITH BOTH THE GFS AND ECMWF SHOWING +5C.
AT THIS POINT HAVE OPTED TO INCLUDE A SNOW...SLEET AND FREEZING RAIN
MIX TO THE SOUTHERN HALF OF THE FORECAST AREA INCLUDING THE I-96
CORRIDOR.

THE TUESDAY SYSTEM IS STILL A LOW CONFIDENCE FORECAST IN TERMS OF
THE FINE DETAILS...HOWEVER THE GFS AND ECMWF HAVE CONVERGED ON THE
SYSTEM SLIDING BY THE AREA ON TUESDAY. THERMAL STRUCTURES ARE
SIMILAR AS WELL. DEPTH AND TRACK OF THE LOW ARE WHAT WE NEED TO
FOCUS ON NOW. THE LOW IS NOT AS DEEP AS PAST RUNS. THE ECMWF IS
STILL SHOWING A 997MB LOW PASSING THROUGH NORTHEAST INDIANA.
PRECIPITATION TOTALS ARE ON THE ORDER OF 0.30 TO 0.60 INCHES.
HEAVIER SNOW SWATH WILL LIKELY BE LOCATED ACROSS THE FORECAST
AREA...AS WILL A POTENTIAL MIX.

OVERALL A FAIRLY ACTIVE PERIOD WITH MODERATING TEMPERATURES. DEEP
ARCTIC AIR IS GONE IN THE LONG TERM AND IS REPLACED BY SOUTHWEST
FLOW AND TEMPS CLOSER TO NORMAL.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1223 PM EST THU FEB 26 2015

THE LIGHT SNOW AND LOWER CONDITIONS THAT WERE IN PLACE THIS
MORNING HAVE BEEN IMPROVING ACROSS THE ENTIRE AREA. JUST ABOUT ALL
SITES HAVE TRENDED VFR AS OF 1730Z...EXCEPT A FEW ISOLATED
MARGINAL MVFR CIGS. WE EXPECT ALL ISOLATED MVFR CONDITIONS TO MOVE
OUT/DISSIPATE BY 19Z THIS AFTERNOON. SKIES SHOULD THEN CLEAR OUT
TOWARD SUNSET AND WINDS WILL GO NEARLY CALM.

WE WILL SEE LAKE EFFECT CLOUD COVER WELL OUT OVER THE LAKE...
EVENTUALLY BEGIN TO MOVE INLAND LATER TONIGHT AND ON FRI MORNING
AS WINDS IN THE CLOUD LAYER EVENTUALLY SHIFT ONSHORE. KMKG WILL
LIKELY SEE THE CLOUDS MOVE IN TOWARD 06Z...AND THEN THE CLOUDS
WILL SPREAD INLAND THEREAFTER. IT LOOKS LIKE TOWARD 12Z FOR KGRR
AND KAZO...AND EVEN LATER FURTHER INLAND. SOME FLURRIES WILL BE
LIKELY...SO WE HAVE INCLUDED A VCSH FOR THE WRN SITES.

&&

.HYDROLOGY...
ISSUED AT 310 PM EST WED FEB 25 2015

RIVER LEVELS ARE HOLDING STEADY WELL BELOW BANKFULL WITH ONLY MINOR
FLUCTUATIONS AT SEVERAL SITES. RIVER SURFACES ARE MOSTLY TO ENTIRELY
ICE/SNOW COVERED AND FLOW UNDERNEATH THE ICE DOES NOT APPEAR TO BE
IMPEDED BY ICE JAMS AT ANY GAUGE SITE CURRENTLY. THE RISK OF
FLOODING WILL REMAIN RATHER LIMITED UNTIL A WARM UP OR SIGNIFICANT
RAINFALL COMES AROUND.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&

$$

SYNOPSIS...LAURENS
SHORT TERM...LAURENS
LONG TERM...DUKE
AVIATION...NJJ
HYDROLOGY...CAS







000
FXUS63 KGRR 261723
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1223 PM EST THU FEB 26 2015

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 330 AM EST THU FEB 26 2015

A FEW LIGHT SNOW SHOWERS AND FLURRIES WILL LINGER ACROSS FAR
SOUTHERN LOWER MICHIGAN THIS MORNING BEFORE HIGH PRESSURE BUILDS
IN TO PRODUCE FAIR BUT COLD WEATHER LATER TODAY THROUGH SATURDAY.
TEMPERATURES WILL FINALLY UNDERGO A GRADUAL MODERATING TREND
SUNDAY INTO EARLY NEXT WEEK.

&&

.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 330 AM EST THU FEB 26 2015

KGRR RADAR TRENDS AND A CONSENSUS OF SHORT RANGE GUIDANCE SUGGESTS
THAT A FEW LIGHT SNOW SHOWERS AND FLURRIES WILL LINGER THIS
MORNING MAINLY SOUTH OF I-96 WITH VERY LIGHT ACCUMULATIONS OF
UNDER AN INCH.

HIGH PRESSURE WILL BUILD IN LATER TODAY THROUGH SATURDAY TO
PRODUCE FAIR BUT VERY COLD WX. MAX TEMPS TODAY WILL ONLY REACH THE
UPPER SINGLE DIGITS TO MIDDLE TEENS.

WIDESPREAD SUB ZERO MIN TEMPS ARE ANTICIPATED TONIGHT AS SKIES
CLEAR AND WINDS GO CALM AND WITH EXPANSIVE SNOW COVER IN PLACE
ACROSS OUR AREA.

MAX TEMPS FRIDAY WILL ONLY REACH THE TEENS IN SPITE OF A FAIR
AMOUNT OF SUN AFTER THE VERY COLD START TO THE DAY. IT WILL BE
VERY COLD FRIDAY NIGHT AS WELL BUT NOT QUITE AS COLD AS TONIGHT
WITH MIN TEMPS GENERALLY IN THE FIVE BELOW TO FIVE ABOVE ZERO RANGE.

A CONSENSUS OF 00Z TIME HEIGHT RH PROGS SUGGESTS THERE WILL BE
PLENTY OF SUN ON SATURDAY. HOWEVER MAX TEMPS SATURDAY WILL ONLY
REACH THE UPPER TEENS TO LOWER 20S.

WIND SPEEDS TONIGHT WILL BE CALM TO LESS THAN 5 MPH. APPARENT
TEMP READINGS MAY FLIRT WITH -15 ACROSS OUR NORTHERN COUNTIES
DURING THE EARLY MORNING HOURS FRIDAY. HOWEVER GIVEN VERY LITTLE
TO NO WIND OVERNIGHT WIND CHILL ADVISORY CRITERIA WILL LIKELY NOT
BE ATTAINED.

.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 330 AM EST THU FEB 26 2015

FELT YESTERDAY AFTERNOON/S LONG TERM DISCUSSION HAD A VERY GOOD
DESCRIPTION AND HANDLE ON THE EXTENDED PERIODS. DID NOT DEVIATE MUCH
FROM THAT THINKING AS THERE WERE NO REAL SURPRISES IN THE EVENING
MODEL RUNS.

THERE ARE STILL TWO MAIN SYSTEMS TO FOCUS ON IN THE LONG TERM...THE
SNOW EVENT FOR LATE SATURDAY NIGHT THROUGH SUNDAY EVENING AND THE
SYSTEM CENTERED ON NEXT TUESDAY.

THE SUNDAY SNOW EVENT HAS BEEN VERY STEADY IN REGARD TO TIMING AND
AMOUNTS. SNOW TOTALS RANGE FROM 1-2 INCHES UP TOWARDS U.S. 10...TO
3-6 INCHES TOWARDS I-94. THE SNOW IS GENERATED VIA UPPER LEVEL
DIVERGENCE ASSOCIATED WITH A STRONG JET STREAK...LOW LEVEL
ISENTROPIC RESPONSE AND A WEAK FRONTAL ZONE. MODELS HAVE BEEN
CONSISTENT WITH AMOUNTS FROM RUN TO RUN AND MODEL TO MODEL...SO
CONFIDENCE IN THE SATURDAY NIGHT THROUGH SUNDAY NIGHT SNOW IS FAIRLY
HIGH.

FOCUS THEN SHIFTS TO A LOW THAT DEVELOPS IN THE LEE OF THE ROCKIES
IN SOUTHEAST COLORADO ON MONDAY. THE LOW MOVES NORTHEAST TOWARDS THE
GREAT LAKES AND SHOULD SPREAD SNOW INTO SOUTHWEST LOWER MICHIGAN
LATE MONDAY NIGHT. A MIXTURE OF PRECIPITATION THEN APPEARS POSSIBLE
TUESDAY AND TUESDAY NIGHT AS A GOOD SOUTHERLY FLOW OF MOISTURE AND
WARMTH IS TAPPED. 850MB TEMPERATURES ARE WARM ENOUGH FOR PLAIN RAIN
TUESDAY EVENING ALONG I-94 WITH BOTH THE GFS AND ECMWF SHOWING +5C.
AT THIS POINT HAVE OPTED TO INCLUDE A SNOW...SLEET AND FREEZING RAIN
MIX TO THE SOUTHERN HALF OF THE FORECAST AREA INCLUDING THE I-96
CORRIDOR.

THE TUESDAY SYSTEM IS STILL A LOW CONFIDENCE FORECAST IN TERMS OF
THE FINE DETAILS...HOWEVER THE GFS AND ECMWF HAVE CONVERGED ON THE
SYSTEM SLIDING BY THE AREA ON TUESDAY. THERMAL STRUCTURES ARE
SIMILAR AS WELL. DEPTH AND TRACK OF THE LOW ARE WHAT WE NEED TO
FOCUS ON NOW. THE LOW IS NOT AS DEEP AS PAST RUNS. THE ECMWF IS
STILL SHOWING A 997MB LOW PASSING THROUGH NORTHEAST INDIANA.
PRECIPITATION TOTALS ARE ON THE ORDER OF 0.30 TO 0.60 INCHES.
HEAVIER SNOW SWATH WILL LIKELY BE LOCATED ACROSS THE FORECAST
AREA...AS WILL A POTENTIAL MIX.

OVERALL A FAIRLY ACTIVE PERIOD WITH MODERATING TEMPERATURES. DEEP
ARCTIC AIR IS GONE IN THE LONG TERM AND IS REPLACED BY SOUTHWEST
FLOW AND TEMPS CLOSER TO NORMAL.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1223 PM EST THU FEB 26 2015

THE LIGHT SNOW AND LOWER CONDITIONS THAT WERE IN PLACE THIS
MORNING HAVE BEEN IMPROVING ACROSS THE ENTIRE AREA. JUST ABOUT ALL
SITES HAVE TRENDED VFR AS OF 1730Z...EXCEPT A FEW ISOLATED
MARGINAL MVFR CIGS. WE EXPECT ALL ISOLATED MVFR CONDITIONS TO MOVE
OUT/DISSIPATE BY 19Z THIS AFTERNOON. SKIES SHOULD THEN CLEAR OUT
TOWARD SUNSET AND WINDS WILL GO NEARLY CALM.

WE WILL SEE LAKE EFFECT CLOUD COVER WELL OUT OVER THE LAKE...
EVENTUALLY BEGIN TO MOVE INLAND LATER TONIGHT AND ON FRI MORNING
AS WINDS IN THE CLOUD LAYER EVENTUALLY SHIFT ONSHORE. KMKG WILL
LIKELY SEE THE CLOUDS MOVE IN TOWARD 06Z...AND THEN THE CLOUDS
WILL SPREAD INLAND THEREAFTER. IT LOOKS LIKE TOWARD 12Z FOR KGRR
AND KAZO...AND EVEN LATER FURTHER INLAND. SOME FLURRIES WILL BE
LIKELY...SO WE HAVE INCLUDED A VCSH FOR THE WRN SITES.

&&

.HYDROLOGY...
ISSUED AT 310 PM EST WED FEB 25 2015

RIVER LEVELS ARE HOLDING STEADY WELL BELOW BANKFULL WITH ONLY MINOR
FLUCTUATIONS AT SEVERAL SITES. RIVER SURFACES ARE MOSTLY TO ENTIRELY
ICE/SNOW COVERED AND FLOW UNDERNEATH THE ICE DOES NOT APPEAR TO BE
IMPEDED BY ICE JAMS AT ANY GAUGE SITE CURRENTLY. THE RISK OF
FLOODING WILL REMAIN RATHER LIMITED UNTIL A WARM UP OR SIGNIFICANT
RAINFALL COMES AROUND.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&

$$

SYNOPSIS...LAURENS
SHORT TERM...LAURENS
LONG TERM...DUKE
AVIATION...NJJ
HYDROLOGY...CAS








000
FXUS63 KGRR 261214
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
714 AM EST THU FEB 26 2015

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 330 AM EST THU FEB 26 2015

A FEW LIGHT SNOW SHOWERS AND FLURRIES WILL LINGER ACROSS FAR
SOUTHERN LOWER MICHIGAN THIS MORNING BEFORE HIGH PRESSURE BUILDS
IN TO PRODUCE FAIR BUT COLD WEATHER LATER TODAY THROUGH SATURDAY.
TEMPERATURES WILL FINALLY UNDERGO A GRADUAL MODERATING TREND
SUNDAY INTO EARLY NEXT WEEK.

&&

.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 330 AM EST THU FEB 26 2015

KGRR RADAR TRENDS AND A CONSENSUS OF SHORT RANGE GUIDANCE SUGGESTS
THAT A FEW LIGHT SNOW SHOWERS AND FLURRIES WILL LINGER THIS
MORNING MAINLY SOUTH OF I-96 WITH VERY LIGHT ACCUMULATIONS OF
UNDER AN INCH.

HIGH PRESSURE WILL BUILD IN LATER TODAY THROUGH SATURDAY TO
PRODUCE FAIR BUT VERY COLD WX. MAX TEMPS TODAY WILL ONLY REACH THE
UPPER SINGLE DIGITS TO MIDDLE TEENS.

WIDESPREAD SUB ZERO MIN TEMPS ARE ANTICIPATED TONIGHT AS SKIES
CLEAR AND WINDS GO CALM AND WITH EXPANSIVE SNOW COVER IN PLACE
ACROSS OUR AREA.

MAX TEMPS FRIDAY WILL ONLY REACH THE TEENS IN SPITE OF A FAIR
AMOUNT OF SUN AFTER THE VERY COLD START TO THE DAY. IT WILL BE
VERY COLD FRIDAY NIGHT AS WELL BUT NOT QUITE AS COLD AS TONIGHT
WITH MIN TEMPS GENERALLY IN THE FIVE BELOW TO FIVE ABOVE ZERO RANGE.

A CONSENSUS OF 00Z TIME HEIGHT RH PROGS SUGGESTS THERE WILL BE
PLENTY OF SUN ON SATURDAY. HOWEVER MAX TEMPS SATURDAY WILL ONLY
REACH THE UPPER TEENS TO LOWER 20S.

WIND SPEEDS TONIGHT WILL BE CALM TO LESS THAN 5 MPH. APPARENT
TEMP READINGS MAY FLIRT WITH -15 ACROSS OUR NORTHERN COUNTIES
DURING THE EARLY MORNING HOURS FRIDAY. HOWEVER GIVEN VERY LITTLE
TO NO WIND OVERNIGHT WIND CHILL ADVISORY CRITERIA WILL LIKELY NOT
BE ATTAINED.

.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 330 AM EST THU FEB 26 2015

FELT YESTERDAY AFTERNOON/S LONG TERM DISCUSSION HAD A VERY GOOD
DESCRIPTION AND HANDLE ON THE EXTENDED PERIODS. DID NOT DEVIATE MUCH
FROM THAT THINKING AS THERE WERE NO REAL SURPRISES IN THE EVENING
MODEL RUNS.

THERE ARE STILL TWO MAIN SYSTEMS TO FOCUS ON IN THE LONG TERM...THE
SNOW EVENT FOR LATE SATURDAY NIGHT THROUGH SUNDAY EVENING AND THE
SYSTEM CENTERED ON NEXT TUESDAY.

THE SUNDAY SNOW EVENT HAS BEEN VERY STEADY IN REGARD TO TIMING AND
AMOUNTS. SNOW TOTALS RANGE FROM 1-2 INCHES UP TOWARDS U.S. 10...TO
3-6 INCHES TOWARDS I-94. THE SNOW IS GENERATED VIA UPPER LEVEL
DIVERGENCE ASSOCIATED WITH A STRONG JET STREAK...LOW LEVEL
ISENTROPIC RESPONSE AND A WEAK FRONTAL ZONE. MODELS HAVE BEEN
CONSISTENT WITH AMOUNTS FROM RUN TO RUN AND MODEL TO MODEL...SO
CONFIDENCE IN THE SATURDAY NIGHT THROUGH SUNDAY NIGHT SNOW IS FAIRLY
HIGH.

FOCUS THEN SHIFTS TO A LOW THAT DEVELOPS IN THE LEE OF THE ROCKIES
IN SOUTHEAST COLORADO ON MONDAY. THE LOW MOVES NORTHEAST TOWARDS THE
GREAT LAKES AND SHOULD SPREAD SNOW INTO SOUTHWEST LOWER MICHIGAN
LATE MONDAY NIGHT. A MIXTURE OF PRECIPITATION THEN APPEARS POSSIBLE
TUESDAY AND TUESDAY NIGHT AS A GOOD SOUTHERLY FLOW OF MOISTURE AND
WARMTH IS TAPPED. 850MB TEMPERATURES ARE WARM ENOUGH FOR PLAIN RAIN
TUESDAY EVENING ALONG I-94 WITH BOTH THE GFS AND ECMWF SHOWING +5C.
AT THIS POINT HAVE OPTED TO INCLUDE A SNOW...SLEET AND FREEZING RAIN
MIX TO THE SOUTHERN HALF OF THE FORECAST AREA INCLUDING THE I-96
CORRIDOR.

THE TUESDAY SYSTEM IS STILL A LOW CONFIDENCE FORECAST IN TERMS OF
THE FINE DETAILS...HOWEVER THE GFS AND ECMWF HAVE CONVERGED ON THE
SYSTEM SLIDING BY THE AREA ON TUESDAY. THERMAL STRUCTURES ARE
SIMILAR AS WELL. DEPTH AND TRACK OF THE LOW ARE WHAT WE NEED TO
FOCUS ON NOW. THE LOW IS NOT AS DEEP AS PAST RUNS. THE ECWMF IS
STILL SHOWING A 997MB LOW PASSING THROUGH NORTHEAST INDIANA.
PRECIPITATION TOTALS ARE ON THE ORDER OF 0.30 TO 0.60 INCHES.
HEAVIER SNOW SWATH WILL LIKELY BE LOCATED ACROSS THE FORECAST
AREA...AS WILL A POTENTIAL MIX.

OVERALL A FAIRLY ACTIVE PERIOD WITH MODERATING TEMPERATURES. DEEP
ARCTIC AIR IS GONE IN THE LONG TERM AND IS REPLACED BY SOUTHWEST
FLOW AND TEMPS CLOSER TO NORMAL.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 713 AM EST THU FEB 26 2015

MVFR CEILINGS AND VISIBILITIES REMAIN ACROSS MOST OF THE TAF
SITES AT 12Z. SOME IFR IS INTERSPERSED FROM KGRR OFF TO THE SOUTH
AND EAST THROUGH 15Z. KMKG REMAINS VFR...WHERE THE SNOW HAS MISSED
OVERNIGHT.

THE SNOW SHOULD PEEL AWAY TO THE SOUTHEAST THROUGH THE COURSE OF
THE MORNING...ENDING BY 16Z. CONDITIONS SHOULD TURN VFR AT ALL OF
THE TAF SITES BY MIDDAY AS WELL. SOME BROKEN VFR CEILINGS WITH
BASES AROUND 3500FT MAY HANG ON FOR A GOOD DEAL OF THE AFTERNOON
ALONG I-94.

THROUGH THE COURSE OF THE AFTERNOON AND EVENING SKIES SHOULD
CLEAR. OVERNIGHT SOME VFR LAKE EFFECT CLOUDS WITH BASES AROUND
3500FT SHOULD PUSH BACK IN TO KMKG AND KGRR.

NORTHEAST WINDS AROUND 10 KNOTS THIS MORNING WILL SHIFT NORTH THIS
AFTERNOON.

&&

.HYDROLOGY...
ISSUED AT 310 PM EST WED FEB 25 2015

RIVER LEVELS ARE HOLDING STEADY WELL BELOW BANKFULL WITH ONLY MINOR
FLUCTUATIONS AT SEVERAL SITES. RIVER SURFACES ARE MOSTLY TO ENTIRELY
ICE/SNOW COVERED AND FLOW UNDERNEATH THE ICE DOES NOT APPEAR TO BE
IMPEDED BY ICE JAMS AT ANY GAUGE SITE CURRENTLY. THE RISK OF
FLOODING WILL REMAIN RATHER LIMITED UNTIL A WARM UP OR SIGNIFICANT
RAINFALL COMES AROUND.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&

$$

SYNOPSIS...LAURENS
SHORT TERM...LAURENS
LONG TERM...DUKE
AVIATION...DUKE
HYDROLOGY...CAS






000
FXUS63 KGRR 261214
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
714 AM EST THU FEB 26 2015

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 330 AM EST THU FEB 26 2015

A FEW LIGHT SNOW SHOWERS AND FLURRIES WILL LINGER ACROSS FAR
SOUTHERN LOWER MICHIGAN THIS MORNING BEFORE HIGH PRESSURE BUILDS
IN TO PRODUCE FAIR BUT COLD WEATHER LATER TODAY THROUGH SATURDAY.
TEMPERATURES WILL FINALLY UNDERGO A GRADUAL MODERATING TREND
SUNDAY INTO EARLY NEXT WEEK.

&&

.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 330 AM EST THU FEB 26 2015

KGRR RADAR TRENDS AND A CONSENSUS OF SHORT RANGE GUIDANCE SUGGESTS
THAT A FEW LIGHT SNOW SHOWERS AND FLURRIES WILL LINGER THIS
MORNING MAINLY SOUTH OF I-96 WITH VERY LIGHT ACCUMULATIONS OF
UNDER AN INCH.

HIGH PRESSURE WILL BUILD IN LATER TODAY THROUGH SATURDAY TO
PRODUCE FAIR BUT VERY COLD WX. MAX TEMPS TODAY WILL ONLY REACH THE
UPPER SINGLE DIGITS TO MIDDLE TEENS.

WIDESPREAD SUB ZERO MIN TEMPS ARE ANTICIPATED TONIGHT AS SKIES
CLEAR AND WINDS GO CALM AND WITH EXPANSIVE SNOW COVER IN PLACE
ACROSS OUR AREA.

MAX TEMPS FRIDAY WILL ONLY REACH THE TEENS IN SPITE OF A FAIR
AMOUNT OF SUN AFTER THE VERY COLD START TO THE DAY. IT WILL BE
VERY COLD FRIDAY NIGHT AS WELL BUT NOT QUITE AS COLD AS TONIGHT
WITH MIN TEMPS GENERALLY IN THE FIVE BELOW TO FIVE ABOVE ZERO RANGE.

A CONSENSUS OF 00Z TIME HEIGHT RH PROGS SUGGESTS THERE WILL BE
PLENTY OF SUN ON SATURDAY. HOWEVER MAX TEMPS SATURDAY WILL ONLY
REACH THE UPPER TEENS TO LOWER 20S.

WIND SPEEDS TONIGHT WILL BE CALM TO LESS THAN 5 MPH. APPARENT
TEMP READINGS MAY FLIRT WITH -15 ACROSS OUR NORTHERN COUNTIES
DURING THE EARLY MORNING HOURS FRIDAY. HOWEVER GIVEN VERY LITTLE
TO NO WIND OVERNIGHT WIND CHILL ADVISORY CRITERIA WILL LIKELY NOT
BE ATTAINED.

.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 330 AM EST THU FEB 26 2015

FELT YESTERDAY AFTERNOON/S LONG TERM DISCUSSION HAD A VERY GOOD
DESCRIPTION AND HANDLE ON THE EXTENDED PERIODS. DID NOT DEVIATE MUCH
FROM THAT THINKING AS THERE WERE NO REAL SURPRISES IN THE EVENING
MODEL RUNS.

THERE ARE STILL TWO MAIN SYSTEMS TO FOCUS ON IN THE LONG TERM...THE
SNOW EVENT FOR LATE SATURDAY NIGHT THROUGH SUNDAY EVENING AND THE
SYSTEM CENTERED ON NEXT TUESDAY.

THE SUNDAY SNOW EVENT HAS BEEN VERY STEADY IN REGARD TO TIMING AND
AMOUNTS. SNOW TOTALS RANGE FROM 1-2 INCHES UP TOWARDS U.S. 10...TO
3-6 INCHES TOWARDS I-94. THE SNOW IS GENERATED VIA UPPER LEVEL
DIVERGENCE ASSOCIATED WITH A STRONG JET STREAK...LOW LEVEL
ISENTROPIC RESPONSE AND A WEAK FRONTAL ZONE. MODELS HAVE BEEN
CONSISTENT WITH AMOUNTS FROM RUN TO RUN AND MODEL TO MODEL...SO
CONFIDENCE IN THE SATURDAY NIGHT THROUGH SUNDAY NIGHT SNOW IS FAIRLY
HIGH.

FOCUS THEN SHIFTS TO A LOW THAT DEVELOPS IN THE LEE OF THE ROCKIES
IN SOUTHEAST COLORADO ON MONDAY. THE LOW MOVES NORTHEAST TOWARDS THE
GREAT LAKES AND SHOULD SPREAD SNOW INTO SOUTHWEST LOWER MICHIGAN
LATE MONDAY NIGHT. A MIXTURE OF PRECIPITATION THEN APPEARS POSSIBLE
TUESDAY AND TUESDAY NIGHT AS A GOOD SOUTHERLY FLOW OF MOISTURE AND
WARMTH IS TAPPED. 850MB TEMPERATURES ARE WARM ENOUGH FOR PLAIN RAIN
TUESDAY EVENING ALONG I-94 WITH BOTH THE GFS AND ECMWF SHOWING +5C.
AT THIS POINT HAVE OPTED TO INCLUDE A SNOW...SLEET AND FREEZING RAIN
MIX TO THE SOUTHERN HALF OF THE FORECAST AREA INCLUDING THE I-96
CORRIDOR.

THE TUESDAY SYSTEM IS STILL A LOW CONFIDENCE FORECAST IN TERMS OF
THE FINE DETAILS...HOWEVER THE GFS AND ECMWF HAVE CONVERGED ON THE
SYSTEM SLIDING BY THE AREA ON TUESDAY. THERMAL STRUCTURES ARE
SIMILAR AS WELL. DEPTH AND TRACK OF THE LOW ARE WHAT WE NEED TO
FOCUS ON NOW. THE LOW IS NOT AS DEEP AS PAST RUNS. THE ECWMF IS
STILL SHOWING A 997MB LOW PASSING THROUGH NORTHEAST INDIANA.
PRECIPITATION TOTALS ARE ON THE ORDER OF 0.30 TO 0.60 INCHES.
HEAVIER SNOW SWATH WILL LIKELY BE LOCATED ACROSS THE FORECAST
AREA...AS WILL A POTENTIAL MIX.

OVERALL A FAIRLY ACTIVE PERIOD WITH MODERATING TEMPERATURES. DEEP
ARCTIC AIR IS GONE IN THE LONG TERM AND IS REPLACED BY SOUTHWEST
FLOW AND TEMPS CLOSER TO NORMAL.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 713 AM EST THU FEB 26 2015

MVFR CEILINGS AND VISIBILITIES REMAIN ACROSS MOST OF THE TAF
SITES AT 12Z. SOME IFR IS INTERSPERSED FROM KGRR OFF TO THE SOUTH
AND EAST THROUGH 15Z. KMKG REMAINS VFR...WHERE THE SNOW HAS MISSED
OVERNIGHT.

THE SNOW SHOULD PEEL AWAY TO THE SOUTHEAST THROUGH THE COURSE OF
THE MORNING...ENDING BY 16Z. CONDITIONS SHOULD TURN VFR AT ALL OF
THE TAF SITES BY MIDDAY AS WELL. SOME BROKEN VFR CEILINGS WITH
BASES AROUND 3500FT MAY HANG ON FOR A GOOD DEAL OF THE AFTERNOON
ALONG I-94.

THROUGH THE COURSE OF THE AFTERNOON AND EVENING SKIES SHOULD
CLEAR. OVERNIGHT SOME VFR LAKE EFFECT CLOUDS WITH BASES AROUND
3500FT SHOULD PUSH BACK IN TO KMKG AND KGRR.

NORTHEAST WINDS AROUND 10 KNOTS THIS MORNING WILL SHIFT NORTH THIS
AFTERNOON.

&&

.HYDROLOGY...
ISSUED AT 310 PM EST WED FEB 25 2015

RIVER LEVELS ARE HOLDING STEADY WELL BELOW BANKFULL WITH ONLY MINOR
FLUCTUATIONS AT SEVERAL SITES. RIVER SURFACES ARE MOSTLY TO ENTIRELY
ICE/SNOW COVERED AND FLOW UNDERNEATH THE ICE DOES NOT APPEAR TO BE
IMPEDED BY ICE JAMS AT ANY GAUGE SITE CURRENTLY. THE RISK OF
FLOODING WILL REMAIN RATHER LIMITED UNTIL A WARM UP OR SIGNIFICANT
RAINFALL COMES AROUND.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&

$$

SYNOPSIS...LAURENS
SHORT TERM...LAURENS
LONG TERM...DUKE
AVIATION...DUKE
HYDROLOGY...CAS





000
FXUS63 KGRR 261214
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
714 AM EST THU FEB 26 2015

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 330 AM EST THU FEB 26 2015

A FEW LIGHT SNOW SHOWERS AND FLURRIES WILL LINGER ACROSS FAR
SOUTHERN LOWER MICHIGAN THIS MORNING BEFORE HIGH PRESSURE BUILDS
IN TO PRODUCE FAIR BUT COLD WEATHER LATER TODAY THROUGH SATURDAY.
TEMPERATURES WILL FINALLY UNDERGO A GRADUAL MODERATING TREND
SUNDAY INTO EARLY NEXT WEEK.

&&

.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 330 AM EST THU FEB 26 2015

KGRR RADAR TRENDS AND A CONSENSUS OF SHORT RANGE GUIDANCE SUGGESTS
THAT A FEW LIGHT SNOW SHOWERS AND FLURRIES WILL LINGER THIS
MORNING MAINLY SOUTH OF I-96 WITH VERY LIGHT ACCUMULATIONS OF
UNDER AN INCH.

HIGH PRESSURE WILL BUILD IN LATER TODAY THROUGH SATURDAY TO
PRODUCE FAIR BUT VERY COLD WX. MAX TEMPS TODAY WILL ONLY REACH THE
UPPER SINGLE DIGITS TO MIDDLE TEENS.

WIDESPREAD SUB ZERO MIN TEMPS ARE ANTICIPATED TONIGHT AS SKIES
CLEAR AND WINDS GO CALM AND WITH EXPANSIVE SNOW COVER IN PLACE
ACROSS OUR AREA.

MAX TEMPS FRIDAY WILL ONLY REACH THE TEENS IN SPITE OF A FAIR
AMOUNT OF SUN AFTER THE VERY COLD START TO THE DAY. IT WILL BE
VERY COLD FRIDAY NIGHT AS WELL BUT NOT QUITE AS COLD AS TONIGHT
WITH MIN TEMPS GENERALLY IN THE FIVE BELOW TO FIVE ABOVE ZERO RANGE.

A CONSENSUS OF 00Z TIME HEIGHT RH PROGS SUGGESTS THERE WILL BE
PLENTY OF SUN ON SATURDAY. HOWEVER MAX TEMPS SATURDAY WILL ONLY
REACH THE UPPER TEENS TO LOWER 20S.

WIND SPEEDS TONIGHT WILL BE CALM TO LESS THAN 5 MPH. APPARENT
TEMP READINGS MAY FLIRT WITH -15 ACROSS OUR NORTHERN COUNTIES
DURING THE EARLY MORNING HOURS FRIDAY. HOWEVER GIVEN VERY LITTLE
TO NO WIND OVERNIGHT WIND CHILL ADVISORY CRITERIA WILL LIKELY NOT
BE ATTAINED.

.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 330 AM EST THU FEB 26 2015

FELT YESTERDAY AFTERNOON/S LONG TERM DISCUSSION HAD A VERY GOOD
DESCRIPTION AND HANDLE ON THE EXTENDED PERIODS. DID NOT DEVIATE MUCH
FROM THAT THINKING AS THERE WERE NO REAL SURPRISES IN THE EVENING
MODEL RUNS.

THERE ARE STILL TWO MAIN SYSTEMS TO FOCUS ON IN THE LONG TERM...THE
SNOW EVENT FOR LATE SATURDAY NIGHT THROUGH SUNDAY EVENING AND THE
SYSTEM CENTERED ON NEXT TUESDAY.

THE SUNDAY SNOW EVENT HAS BEEN VERY STEADY IN REGARD TO TIMING AND
AMOUNTS. SNOW TOTALS RANGE FROM 1-2 INCHES UP TOWARDS U.S. 10...TO
3-6 INCHES TOWARDS I-94. THE SNOW IS GENERATED VIA UPPER LEVEL
DIVERGENCE ASSOCIATED WITH A STRONG JET STREAK...LOW LEVEL
ISENTROPIC RESPONSE AND A WEAK FRONTAL ZONE. MODELS HAVE BEEN
CONSISTENT WITH AMOUNTS FROM RUN TO RUN AND MODEL TO MODEL...SO
CONFIDENCE IN THE SATURDAY NIGHT THROUGH SUNDAY NIGHT SNOW IS FAIRLY
HIGH.

FOCUS THEN SHIFTS TO A LOW THAT DEVELOPS IN THE LEE OF THE ROCKIES
IN SOUTHEAST COLORADO ON MONDAY. THE LOW MOVES NORTHEAST TOWARDS THE
GREAT LAKES AND SHOULD SPREAD SNOW INTO SOUTHWEST LOWER MICHIGAN
LATE MONDAY NIGHT. A MIXTURE OF PRECIPITATION THEN APPEARS POSSIBLE
TUESDAY AND TUESDAY NIGHT AS A GOOD SOUTHERLY FLOW OF MOISTURE AND
WARMTH IS TAPPED. 850MB TEMPERATURES ARE WARM ENOUGH FOR PLAIN RAIN
TUESDAY EVENING ALONG I-94 WITH BOTH THE GFS AND ECMWF SHOWING +5C.
AT THIS POINT HAVE OPTED TO INCLUDE A SNOW...SLEET AND FREEZING RAIN
MIX TO THE SOUTHERN HALF OF THE FORECAST AREA INCLUDING THE I-96
CORRIDOR.

THE TUESDAY SYSTEM IS STILL A LOW CONFIDENCE FORECAST IN TERMS OF
THE FINE DETAILS...HOWEVER THE GFS AND ECMWF HAVE CONVERGED ON THE
SYSTEM SLIDING BY THE AREA ON TUESDAY. THERMAL STRUCTURES ARE
SIMILAR AS WELL. DEPTH AND TRACK OF THE LOW ARE WHAT WE NEED TO
FOCUS ON NOW. THE LOW IS NOT AS DEEP AS PAST RUNS. THE ECWMF IS
STILL SHOWING A 997MB LOW PASSING THROUGH NORTHEAST INDIANA.
PRECIPITATION TOTALS ARE ON THE ORDER OF 0.30 TO 0.60 INCHES.
HEAVIER SNOW SWATH WILL LIKELY BE LOCATED ACROSS THE FORECAST
AREA...AS WILL A POTENTIAL MIX.

OVERALL A FAIRLY ACTIVE PERIOD WITH MODERATING TEMPERATURES. DEEP
ARCTIC AIR IS GONE IN THE LONG TERM AND IS REPLACED BY SOUTHWEST
FLOW AND TEMPS CLOSER TO NORMAL.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 713 AM EST THU FEB 26 2015

MVFR CEILINGS AND VISIBILITIES REMAIN ACROSS MOST OF THE TAF
SITES AT 12Z. SOME IFR IS INTERSPERSED FROM KGRR OFF TO THE SOUTH
AND EAST THROUGH 15Z. KMKG REMAINS VFR...WHERE THE SNOW HAS MISSED
OVERNIGHT.

THE SNOW SHOULD PEEL AWAY TO THE SOUTHEAST THROUGH THE COURSE OF
THE MORNING...ENDING BY 16Z. CONDITIONS SHOULD TURN VFR AT ALL OF
THE TAF SITES BY MIDDAY AS WELL. SOME BROKEN VFR CEILINGS WITH
BASES AROUND 3500FT MAY HANG ON FOR A GOOD DEAL OF THE AFTERNOON
ALONG I-94.

THROUGH THE COURSE OF THE AFTERNOON AND EVENING SKIES SHOULD
CLEAR. OVERNIGHT SOME VFR LAKE EFFECT CLOUDS WITH BASES AROUND
3500FT SHOULD PUSH BACK IN TO KMKG AND KGRR.

NORTHEAST WINDS AROUND 10 KNOTS THIS MORNING WILL SHIFT NORTH THIS
AFTERNOON.

&&

.HYDROLOGY...
ISSUED AT 310 PM EST WED FEB 25 2015

RIVER LEVELS ARE HOLDING STEADY WELL BELOW BANKFULL WITH ONLY MINOR
FLUCTUATIONS AT SEVERAL SITES. RIVER SURFACES ARE MOSTLY TO ENTIRELY
ICE/SNOW COVERED AND FLOW UNDERNEATH THE ICE DOES NOT APPEAR TO BE
IMPEDED BY ICE JAMS AT ANY GAUGE SITE CURRENTLY. THE RISK OF
FLOODING WILL REMAIN RATHER LIMITED UNTIL A WARM UP OR SIGNIFICANT
RAINFALL COMES AROUND.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&

$$

SYNOPSIS...LAURENS
SHORT TERM...LAURENS
LONG TERM...DUKE
AVIATION...DUKE
HYDROLOGY...CAS





000
FXUS63 KGRR 261214
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
714 AM EST THU FEB 26 2015

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 330 AM EST THU FEB 26 2015

A FEW LIGHT SNOW SHOWERS AND FLURRIES WILL LINGER ACROSS FAR
SOUTHERN LOWER MICHIGAN THIS MORNING BEFORE HIGH PRESSURE BUILDS
IN TO PRODUCE FAIR BUT COLD WEATHER LATER TODAY THROUGH SATURDAY.
TEMPERATURES WILL FINALLY UNDERGO A GRADUAL MODERATING TREND
SUNDAY INTO EARLY NEXT WEEK.

&&

.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 330 AM EST THU FEB 26 2015

KGRR RADAR TRENDS AND A CONSENSUS OF SHORT RANGE GUIDANCE SUGGESTS
THAT A FEW LIGHT SNOW SHOWERS AND FLURRIES WILL LINGER THIS
MORNING MAINLY SOUTH OF I-96 WITH VERY LIGHT ACCUMULATIONS OF
UNDER AN INCH.

HIGH PRESSURE WILL BUILD IN LATER TODAY THROUGH SATURDAY TO
PRODUCE FAIR BUT VERY COLD WX. MAX TEMPS TODAY WILL ONLY REACH THE
UPPER SINGLE DIGITS TO MIDDLE TEENS.

WIDESPREAD SUB ZERO MIN TEMPS ARE ANTICIPATED TONIGHT AS SKIES
CLEAR AND WINDS GO CALM AND WITH EXPANSIVE SNOW COVER IN PLACE
ACROSS OUR AREA.

MAX TEMPS FRIDAY WILL ONLY REACH THE TEENS IN SPITE OF A FAIR
AMOUNT OF SUN AFTER THE VERY COLD START TO THE DAY. IT WILL BE
VERY COLD FRIDAY NIGHT AS WELL BUT NOT QUITE AS COLD AS TONIGHT
WITH MIN TEMPS GENERALLY IN THE FIVE BELOW TO FIVE ABOVE ZERO RANGE.

A CONSENSUS OF 00Z TIME HEIGHT RH PROGS SUGGESTS THERE WILL BE
PLENTY OF SUN ON SATURDAY. HOWEVER MAX TEMPS SATURDAY WILL ONLY
REACH THE UPPER TEENS TO LOWER 20S.

WIND SPEEDS TONIGHT WILL BE CALM TO LESS THAN 5 MPH. APPARENT
TEMP READINGS MAY FLIRT WITH -15 ACROSS OUR NORTHERN COUNTIES
DURING THE EARLY MORNING HOURS FRIDAY. HOWEVER GIVEN VERY LITTLE
TO NO WIND OVERNIGHT WIND CHILL ADVISORY CRITERIA WILL LIKELY NOT
BE ATTAINED.

.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 330 AM EST THU FEB 26 2015

FELT YESTERDAY AFTERNOON/S LONG TERM DISCUSSION HAD A VERY GOOD
DESCRIPTION AND HANDLE ON THE EXTENDED PERIODS. DID NOT DEVIATE MUCH
FROM THAT THINKING AS THERE WERE NO REAL SURPRISES IN THE EVENING
MODEL RUNS.

THERE ARE STILL TWO MAIN SYSTEMS TO FOCUS ON IN THE LONG TERM...THE
SNOW EVENT FOR LATE SATURDAY NIGHT THROUGH SUNDAY EVENING AND THE
SYSTEM CENTERED ON NEXT TUESDAY.

THE SUNDAY SNOW EVENT HAS BEEN VERY STEADY IN REGARD TO TIMING AND
AMOUNTS. SNOW TOTALS RANGE FROM 1-2 INCHES UP TOWARDS U.S. 10...TO
3-6 INCHES TOWARDS I-94. THE SNOW IS GENERATED VIA UPPER LEVEL
DIVERGENCE ASSOCIATED WITH A STRONG JET STREAK...LOW LEVEL
ISENTROPIC RESPONSE AND A WEAK FRONTAL ZONE. MODELS HAVE BEEN
CONSISTENT WITH AMOUNTS FROM RUN TO RUN AND MODEL TO MODEL...SO
CONFIDENCE IN THE SATURDAY NIGHT THROUGH SUNDAY NIGHT SNOW IS FAIRLY
HIGH.

FOCUS THEN SHIFTS TO A LOW THAT DEVELOPS IN THE LEE OF THE ROCKIES
IN SOUTHEAST COLORADO ON MONDAY. THE LOW MOVES NORTHEAST TOWARDS THE
GREAT LAKES AND SHOULD SPREAD SNOW INTO SOUTHWEST LOWER MICHIGAN
LATE MONDAY NIGHT. A MIXTURE OF PRECIPITATION THEN APPEARS POSSIBLE
TUESDAY AND TUESDAY NIGHT AS A GOOD SOUTHERLY FLOW OF MOISTURE AND
WARMTH IS TAPPED. 850MB TEMPERATURES ARE WARM ENOUGH FOR PLAIN RAIN
TUESDAY EVENING ALONG I-94 WITH BOTH THE GFS AND ECMWF SHOWING +5C.
AT THIS POINT HAVE OPTED TO INCLUDE A SNOW...SLEET AND FREEZING RAIN
MIX TO THE SOUTHERN HALF OF THE FORECAST AREA INCLUDING THE I-96
CORRIDOR.

THE TUESDAY SYSTEM IS STILL A LOW CONFIDENCE FORECAST IN TERMS OF
THE FINE DETAILS...HOWEVER THE GFS AND ECMWF HAVE CONVERGED ON THE
SYSTEM SLIDING BY THE AREA ON TUESDAY. THERMAL STRUCTURES ARE
SIMILAR AS WELL. DEPTH AND TRACK OF THE LOW ARE WHAT WE NEED TO
FOCUS ON NOW. THE LOW IS NOT AS DEEP AS PAST RUNS. THE ECWMF IS
STILL SHOWING A 997MB LOW PASSING THROUGH NORTHEAST INDIANA.
PRECIPITATION TOTALS ARE ON THE ORDER OF 0.30 TO 0.60 INCHES.
HEAVIER SNOW SWATH WILL LIKELY BE LOCATED ACROSS THE FORECAST
AREA...AS WILL A POTENTIAL MIX.

OVERALL A FAIRLY ACTIVE PERIOD WITH MODERATING TEMPERATURES. DEEP
ARCTIC AIR IS GONE IN THE LONG TERM AND IS REPLACED BY SOUTHWEST
FLOW AND TEMPS CLOSER TO NORMAL.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 713 AM EST THU FEB 26 2015

MVFR CEILINGS AND VISIBILITIES REMAIN ACROSS MOST OF THE TAF
SITES AT 12Z. SOME IFR IS INTERSPERSED FROM KGRR OFF TO THE SOUTH
AND EAST THROUGH 15Z. KMKG REMAINS VFR...WHERE THE SNOW HAS MISSED
OVERNIGHT.

THE SNOW SHOULD PEEL AWAY TO THE SOUTHEAST THROUGH THE COURSE OF
THE MORNING...ENDING BY 16Z. CONDITIONS SHOULD TURN VFR AT ALL OF
THE TAF SITES BY MIDDAY AS WELL. SOME BROKEN VFR CEILINGS WITH
BASES AROUND 3500FT MAY HANG ON FOR A GOOD DEAL OF THE AFTERNOON
ALONG I-94.

THROUGH THE COURSE OF THE AFTERNOON AND EVENING SKIES SHOULD
CLEAR. OVERNIGHT SOME VFR LAKE EFFECT CLOUDS WITH BASES AROUND
3500FT SHOULD PUSH BACK IN TO KMKG AND KGRR.

NORTHEAST WINDS AROUND 10 KNOTS THIS MORNING WILL SHIFT NORTH THIS
AFTERNOON.

&&

.HYDROLOGY...
ISSUED AT 310 PM EST WED FEB 25 2015

RIVER LEVELS ARE HOLDING STEADY WELL BELOW BANKFULL WITH ONLY MINOR
FLUCTUATIONS AT SEVERAL SITES. RIVER SURFACES ARE MOSTLY TO ENTIRELY
ICE/SNOW COVERED AND FLOW UNDERNEATH THE ICE DOES NOT APPEAR TO BE
IMPEDED BY ICE JAMS AT ANY GAUGE SITE CURRENTLY. THE RISK OF
FLOODING WILL REMAIN RATHER LIMITED UNTIL A WARM UP OR SIGNIFICANT
RAINFALL COMES AROUND.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&

$$

SYNOPSIS...LAURENS
SHORT TERM...LAURENS
LONG TERM...DUKE
AVIATION...DUKE
HYDROLOGY...CAS






000
FXUS63 KGRR 260827
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
330 AM EST THU FEB 26 2015

LATEST UPDATE...
SYNOPSIS/SHORT TERM/LONG TERM

.SYNOPSIS...
ISSUED AT 330 AM EST THU FEB 26 2015

A FEW LIGHT SNOW SHOWERS AND FLURRIES WILL LINGER ACROSS FAR
SOUTHERN LOWER MICHIGAN THIS MORNING BEFORE HIGH PRESSURE BUILDS
IN TO PRODUCE FAIR BUT COLD WEATHER LATER TODAY THROUGH SATURDAY.
TEMPERATURES WILL FINALLY UNDERGO A GRADUAL MODERATING TREND
SUNDAY INTO EARLY NEXT WEEK.

&&

.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 330 AM EST THU FEB 26 2015

KGRR RADAR TRENDS AND A CONSENSUS OF SHORT RANGE GUIDANCE SUGGESTS
THAT A FEW LIGHT SNOW SHOWERS AND FLURRIES WILL LINGER THIS
MORNING MAINLY SOUTH OF I-96 WITH VERY LIGHT ACCUMULATIONS OF
UNDER AN INCH.

HIGH PRESSURE WILL BUILD IN LATER TODAY THROUGH SATURDAY TO
PRODUCE FAIR BUT VERY COLD WX. MAX TEMPS TODAY WILL ONLY REACH THE
UPPER SINGLE DIGITS TO MIDDLE TEENS.

WIDESPREAD SUB ZERO MIN TEMPS ARE ANTICIPATED TONIGHT AS SKIES
CLEAR AND WINDS GO CALM AND WITH EXPANSIVE SNOW COVER IN PLACE
ACROSS OUR AREA.

MAX TEMPS FRIDAY WILL ONLY REACH THE TEENS IN SPITE OF A FAIR
AMOUNT OF SUN AFTER THE VERY COLD START TO THE DAY. IT WILL BE
VERY COLD FRIDAY NIGHT AS WELL BUT NOT QUITE AS COLD AS TONIGHT
WITH MIN TEMPS GENERALLY IN THE FIVE BELOW TO FIVE ABOVE ZERO RANGE.

A CONSENSUS OF 00Z TIME HEIGHT RH PROGS SUGGESTS THERE WILL BE
PLENTY OF SUN ON SATURDAY. HOWEVER MAX TEMPS SATURDAY WILL ONLY
REACH THE UPPER TEENS TO LOWER 20S.

WIND SPEEDS TONIGHT WILL BE CALM TO LESS THAN 5 MPH. APPARENT
TEMP READINGS MAY FLIRT WITH -15 ACROSS OUR NORTHERN COUNTIES
DURING THE EARLY MORNING HOURS FRIDAY. HOWEVER GIVEN VERY LITTLE
TO NO WIND OVERNIGHT WIND CHILL ADVISORY CRITERIA WILL LIKELY NOT
BE ATTAINED.

.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 330 AM EST THU FEB 26 2015

FELT YESTERDAY AFTERNOON/S LONG TERM DISCUSSION HAD A VERY GOOD
DESCRIPTION AND HANDLE ON THE EXTENDED PERIODS. DID NOT DEVIATE MUCH
FROM THAT THINKING AS THERE WERE NO REAL SURPRISES IN THE EVENING
MODEL RUNS.

THERE ARE STILL TWO MAIN SYSTEMS TO FOCUS ON IN THE LONG TERM...THE
SNOW EVENT FOR LATE SATURDAY NIGHT THROUGH SUNDAY EVENING AND THE
SYSTEM CENTERED ON NEXT TUESDAY.

THE SUNDAY SNOW EVENT HAS BEEN VERY STEADY IN REGARD TO TIMING AND
AMOUNTS. SNOW TOTALS RANGE FROM 1-2 INCHES UP TOWARDS U.S. 10...TO
3-6 INCHES TOWARDS I-94. THE SNOW IS GENERATED VIA UPPER LEVEL
DIVERGENCE ASSOCIATED WITH A STRONG JET STREAK...LOW LEVEL
ISENTROPIC RESPONSE AND A WEAK FRONTAL ZONE. MODELS HAVE BEEN
CONSISTENT WITH AMOUNTS FROM RUN TO RUN AND MODEL TO MODEL...SO
CONFIDENCE IN THE SATURDAY NIGHT THROUGH SUNDAY NIGHT SNOW IS FAIRLY
HIGH.

FOCUS THEN SHIFTS TO A LOW THAT DEVELOPS IN THE LEE OF THE ROCKIES
IN SOUTHEAST COLORADO ON MONDAY. THE LOW MOVES NORTHEAST TOWARDS THE
GREAT LAKES AND SHOULD SPREAD SNOW INTO SOUTHWEST LOWER MICHIGAN
LATE MONDAY NIGHT. A MIXTURE OF PRECIPITATION THEN APPEARS POSSIBLE
TUESDAY AND TUESDAY NIGHT AS A GOOD SOUTHERLY FLOW OF MOISTURE AND
WARMTH IS TAPPED. 850MB TEMPERATURES ARE WARM ENOUGH FOR PLAIN RAIN
TUESDAY EVENING ALONG I-94 WITH BOTH THE GFS AND ECMWF SHOWING +5C.
AT THIS POINT HAVE OPTED TO INCLUDE A SNOW...SLEET AND FREEZING RAIN
MIX TO THE SOUTHERN HALF OF THE FORECAST AREA INCLUDING THE I-96
CORRIDOR.

THE TUESDAY SYSTEM IS STILL A LOW CONFIDENCE FORECAST IN TERMS OF
THE FINE DETAILS...HOWEVER THE GFS AND ECMWF HAVE CONVERGED ON THE
SYSTEM SLIDING BY THE AREA ON TUESDAY. THERMAL STRUCTURES ARE
SIMILAR AS WELL. DEPTH AND TRACK OF THE LOW ARE WHAT WE NEED TO
FOCUS ON NOW. THE LOW IS NOT AS DEEP AS PAST RUNS. THE ECWMF IS
STILL SHOWING A 997MB LOW PASSING THROUGH NORTHEAST INDIANA.
PRECIPITATION TOTALS ARE ON THE ORDER OF 0.30 TO 0.60 INCHES.
HEAVIER SNOW SWATH WILL LIKELY BE LOCATED ACROSS THE FORECAST
AREA...AS WILL A POTENTIAL MIX.

OVERALL A FAIRLY ACTIVE PERIOD WITH MODERATING TEMPERATURES. DEEP
ARCTIC AIR IS GONE IN THE LONG TERM AND IS REPLACED BY SOUTHWEST
FLOW AND TEMPS CLOSER TO NORMAL.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1159 PM EST WED FEB 25 2015

OCCASIONAL LIGHT SNOW WILL BRING VSBYS OF 2-4 MILES OVERNIGHT AND
THURSDAY MORNING MAINLY SOUTH AND EAST OF GRR. THE LIGHT SNOW WILL
END BETWEEN 14Z AND 18Z THURSDAY FROM NORTHWEST TO SOUTHEAST.
MAINLY MVFR CONDITIONS TONIGHT AND THURSDAY MORNING SOUTH AND EAST
OF GRR ARE EXPECTED TO IMPROVE TO PRIMARILY VFR CONDITIONS AFTER
18Z THURSDAY.


&&

.HYDROLOGY...
ISSUED AT 310 PM EST WED FEB 25 2015

RIVER LEVELS ARE HOLDING STEADY WELL BELOW BANKFULL WITH ONLY MINOR
FLUCTUATIONS AT SEVERAL SITES. RIVER SURFACES ARE MOSTLY TO ENTIRELY
ICE/SNOW COVERED AND FLOW UNDERNEATH THE ICE DOES NOT APPEAR TO BE
IMPEDED BY ICE JAMS AT ANY GAUGE SITE CURRENTLY. THE RISK OF
FLOODING WILL REMAIN RATHER LIMITED UNTIL A WARM UP OR SIGNIFICANT
RAINFALL COMES AROUND.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&

$$

SYNOPSIS...LAURENS
SHORT TERM...LAURENS
LONG TERM...DUKE
AVIATION...MEADE
HYDROLOGY...CAS











000
FXUS63 KGRR 260827
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
330 AM EST THU FEB 26 2015

LATEST UPDATE...
SYNOPSIS/SHORT TERM/LONG TERM

.SYNOPSIS...
ISSUED AT 330 AM EST THU FEB 26 2015

A FEW LIGHT SNOW SHOWERS AND FLURRIES WILL LINGER ACROSS FAR
SOUTHERN LOWER MICHIGAN THIS MORNING BEFORE HIGH PRESSURE BUILDS
IN TO PRODUCE FAIR BUT COLD WEATHER LATER TODAY THROUGH SATURDAY.
TEMPERATURES WILL FINALLY UNDERGO A GRADUAL MODERATING TREND
SUNDAY INTO EARLY NEXT WEEK.

&&

.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 330 AM EST THU FEB 26 2015

KGRR RADAR TRENDS AND A CONSENSUS OF SHORT RANGE GUIDANCE SUGGESTS
THAT A FEW LIGHT SNOW SHOWERS AND FLURRIES WILL LINGER THIS
MORNING MAINLY SOUTH OF I-96 WITH VERY LIGHT ACCUMULATIONS OF
UNDER AN INCH.

HIGH PRESSURE WILL BUILD IN LATER TODAY THROUGH SATURDAY TO
PRODUCE FAIR BUT VERY COLD WX. MAX TEMPS TODAY WILL ONLY REACH THE
UPPER SINGLE DIGITS TO MIDDLE TEENS.

WIDESPREAD SUB ZERO MIN TEMPS ARE ANTICIPATED TONIGHT AS SKIES
CLEAR AND WINDS GO CALM AND WITH EXPANSIVE SNOW COVER IN PLACE
ACROSS OUR AREA.

MAX TEMPS FRIDAY WILL ONLY REACH THE TEENS IN SPITE OF A FAIR
AMOUNT OF SUN AFTER THE VERY COLD START TO THE DAY. IT WILL BE
VERY COLD FRIDAY NIGHT AS WELL BUT NOT QUITE AS COLD AS TONIGHT
WITH MIN TEMPS GENERALLY IN THE FIVE BELOW TO FIVE ABOVE ZERO RANGE.

A CONSENSUS OF 00Z TIME HEIGHT RH PROGS SUGGESTS THERE WILL BE
PLENTY OF SUN ON SATURDAY. HOWEVER MAX TEMPS SATURDAY WILL ONLY
REACH THE UPPER TEENS TO LOWER 20S.

WIND SPEEDS TONIGHT WILL BE CALM TO LESS THAN 5 MPH. APPARENT
TEMP READINGS MAY FLIRT WITH -15 ACROSS OUR NORTHERN COUNTIES
DURING THE EARLY MORNING HOURS FRIDAY. HOWEVER GIVEN VERY LITTLE
TO NO WIND OVERNIGHT WIND CHILL ADVISORY CRITERIA WILL LIKELY NOT
BE ATTAINED.

.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 330 AM EST THU FEB 26 2015

FELT YESTERDAY AFTERNOON/S LONG TERM DISCUSSION HAD A VERY GOOD
DESCRIPTION AND HANDLE ON THE EXTENDED PERIODS. DID NOT DEVIATE MUCH
FROM THAT THINKING AS THERE WERE NO REAL SURPRISES IN THE EVENING
MODEL RUNS.

THERE ARE STILL TWO MAIN SYSTEMS TO FOCUS ON IN THE LONG TERM...THE
SNOW EVENT FOR LATE SATURDAY NIGHT THROUGH SUNDAY EVENING AND THE
SYSTEM CENTERED ON NEXT TUESDAY.

THE SUNDAY SNOW EVENT HAS BEEN VERY STEADY IN REGARD TO TIMING AND
AMOUNTS. SNOW TOTALS RANGE FROM 1-2 INCHES UP TOWARDS U.S. 10...TO
3-6 INCHES TOWARDS I-94. THE SNOW IS GENERATED VIA UPPER LEVEL
DIVERGENCE ASSOCIATED WITH A STRONG JET STREAK...LOW LEVEL
ISENTROPIC RESPONSE AND A WEAK FRONTAL ZONE. MODELS HAVE BEEN
CONSISTENT WITH AMOUNTS FROM RUN TO RUN AND MODEL TO MODEL...SO
CONFIDENCE IN THE SATURDAY NIGHT THROUGH SUNDAY NIGHT SNOW IS FAIRLY
HIGH.

FOCUS THEN SHIFTS TO A LOW THAT DEVELOPS IN THE LEE OF THE ROCKIES
IN SOUTHEAST COLORADO ON MONDAY. THE LOW MOVES NORTHEAST TOWARDS THE
GREAT LAKES AND SHOULD SPREAD SNOW INTO SOUTHWEST LOWER MICHIGAN
LATE MONDAY NIGHT. A MIXTURE OF PRECIPITATION THEN APPEARS POSSIBLE
TUESDAY AND TUESDAY NIGHT AS A GOOD SOUTHERLY FLOW OF MOISTURE AND
WARMTH IS TAPPED. 850MB TEMPERATURES ARE WARM ENOUGH FOR PLAIN RAIN
TUESDAY EVENING ALONG I-94 WITH BOTH THE GFS AND ECMWF SHOWING +5C.
AT THIS POINT HAVE OPTED TO INCLUDE A SNOW...SLEET AND FREEZING RAIN
MIX TO THE SOUTHERN HALF OF THE FORECAST AREA INCLUDING THE I-96
CORRIDOR.

THE TUESDAY SYSTEM IS STILL A LOW CONFIDENCE FORECAST IN TERMS OF
THE FINE DETAILS...HOWEVER THE GFS AND ECMWF HAVE CONVERGED ON THE
SYSTEM SLIDING BY THE AREA ON TUESDAY. THERMAL STRUCTURES ARE
SIMILAR AS WELL. DEPTH AND TRACK OF THE LOW ARE WHAT WE NEED TO
FOCUS ON NOW. THE LOW IS NOT AS DEEP AS PAST RUNS. THE ECWMF IS
STILL SHOWING A 997MB LOW PASSING THROUGH NORTHEAST INDIANA.
PRECIPITATION TOTALS ARE ON THE ORDER OF 0.30 TO 0.60 INCHES.
HEAVIER SNOW SWATH WILL LIKELY BE LOCATED ACROSS THE FORECAST
AREA...AS WILL A POTENTIAL MIX.

OVERALL A FAIRLY ACTIVE PERIOD WITH MODERATING TEMPERATURES. DEEP
ARCTIC AIR IS GONE IN THE LONG TERM AND IS REPLACED BY SOUTHWEST
FLOW AND TEMPS CLOSER TO NORMAL.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1159 PM EST WED FEB 25 2015

OCCASIONAL LIGHT SNOW WILL BRING VSBYS OF 2-4 MILES OVERNIGHT AND
THURSDAY MORNING MAINLY SOUTH AND EAST OF GRR. THE LIGHT SNOW WILL
END BETWEEN 14Z AND 18Z THURSDAY FROM NORTHWEST TO SOUTHEAST.
MAINLY MVFR CONDITIONS TONIGHT AND THURSDAY MORNING SOUTH AND EAST
OF GRR ARE EXPECTED TO IMPROVE TO PRIMARILY VFR CONDITIONS AFTER
18Z THURSDAY.


&&

.HYDROLOGY...
ISSUED AT 310 PM EST WED FEB 25 2015

RIVER LEVELS ARE HOLDING STEADY WELL BELOW BANKFULL WITH ONLY MINOR
FLUCTUATIONS AT SEVERAL SITES. RIVER SURFACES ARE MOSTLY TO ENTIRELY
ICE/SNOW COVERED AND FLOW UNDERNEATH THE ICE DOES NOT APPEAR TO BE
IMPEDED BY ICE JAMS AT ANY GAUGE SITE CURRENTLY. THE RISK OF
FLOODING WILL REMAIN RATHER LIMITED UNTIL A WARM UP OR SIGNIFICANT
RAINFALL COMES AROUND.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&

$$

SYNOPSIS...LAURENS
SHORT TERM...LAURENS
LONG TERM...DUKE
AVIATION...MEADE
HYDROLOGY...CAS










000
FXUS63 KGRR 260827
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
330 AM EST THU FEB 26 2015

LATEST UPDATE...
SYNOPSIS/SHORT TERM/LONG TERM

.SYNOPSIS...
ISSUED AT 330 AM EST THU FEB 26 2015

A FEW LIGHT SNOW SHOWERS AND FLURRIES WILL LINGER ACROSS FAR
SOUTHERN LOWER MICHIGAN THIS MORNING BEFORE HIGH PRESSURE BUILDS
IN TO PRODUCE FAIR BUT COLD WEATHER LATER TODAY THROUGH SATURDAY.
TEMPERATURES WILL FINALLY UNDERGO A GRADUAL MODERATING TREND
SUNDAY INTO EARLY NEXT WEEK.

&&

.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 330 AM EST THU FEB 26 2015

KGRR RADAR TRENDS AND A CONSENSUS OF SHORT RANGE GUIDANCE SUGGESTS
THAT A FEW LIGHT SNOW SHOWERS AND FLURRIES WILL LINGER THIS
MORNING MAINLY SOUTH OF I-96 WITH VERY LIGHT ACCUMULATIONS OF
UNDER AN INCH.

HIGH PRESSURE WILL BUILD IN LATER TODAY THROUGH SATURDAY TO
PRODUCE FAIR BUT VERY COLD WX. MAX TEMPS TODAY WILL ONLY REACH THE
UPPER SINGLE DIGITS TO MIDDLE TEENS.

WIDESPREAD SUB ZERO MIN TEMPS ARE ANTICIPATED TONIGHT AS SKIES
CLEAR AND WINDS GO CALM AND WITH EXPANSIVE SNOW COVER IN PLACE
ACROSS OUR AREA.

MAX TEMPS FRIDAY WILL ONLY REACH THE TEENS IN SPITE OF A FAIR
AMOUNT OF SUN AFTER THE VERY COLD START TO THE DAY. IT WILL BE
VERY COLD FRIDAY NIGHT AS WELL BUT NOT QUITE AS COLD AS TONIGHT
WITH MIN TEMPS GENERALLY IN THE FIVE BELOW TO FIVE ABOVE ZERO RANGE.

A CONSENSUS OF 00Z TIME HEIGHT RH PROGS SUGGESTS THERE WILL BE
PLENTY OF SUN ON SATURDAY. HOWEVER MAX TEMPS SATURDAY WILL ONLY
REACH THE UPPER TEENS TO LOWER 20S.

WIND SPEEDS TONIGHT WILL BE CALM TO LESS THAN 5 MPH. APPARENT
TEMP READINGS MAY FLIRT WITH -15 ACROSS OUR NORTHERN COUNTIES
DURING THE EARLY MORNING HOURS FRIDAY. HOWEVER GIVEN VERY LITTLE
TO NO WIND OVERNIGHT WIND CHILL ADVISORY CRITERIA WILL LIKELY NOT
BE ATTAINED.

.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 330 AM EST THU FEB 26 2015

FELT YESTERDAY AFTERNOON/S LONG TERM DISCUSSION HAD A VERY GOOD
DESCRIPTION AND HANDLE ON THE EXTENDED PERIODS. DID NOT DEVIATE MUCH
FROM THAT THINKING AS THERE WERE NO REAL SURPRISES IN THE EVENING
MODEL RUNS.

THERE ARE STILL TWO MAIN SYSTEMS TO FOCUS ON IN THE LONG TERM...THE
SNOW EVENT FOR LATE SATURDAY NIGHT THROUGH SUNDAY EVENING AND THE
SYSTEM CENTERED ON NEXT TUESDAY.

THE SUNDAY SNOW EVENT HAS BEEN VERY STEADY IN REGARD TO TIMING AND
AMOUNTS. SNOW TOTALS RANGE FROM 1-2 INCHES UP TOWARDS U.S. 10...TO
3-6 INCHES TOWARDS I-94. THE SNOW IS GENERATED VIA UPPER LEVEL
DIVERGENCE ASSOCIATED WITH A STRONG JET STREAK...LOW LEVEL
ISENTROPIC RESPONSE AND A WEAK FRONTAL ZONE. MODELS HAVE BEEN
CONSISTENT WITH AMOUNTS FROM RUN TO RUN AND MODEL TO MODEL...SO
CONFIDENCE IN THE SATURDAY NIGHT THROUGH SUNDAY NIGHT SNOW IS FAIRLY
HIGH.

FOCUS THEN SHIFTS TO A LOW THAT DEVELOPS IN THE LEE OF THE ROCKIES
IN SOUTHEAST COLORADO ON MONDAY. THE LOW MOVES NORTHEAST TOWARDS THE
GREAT LAKES AND SHOULD SPREAD SNOW INTO SOUTHWEST LOWER MICHIGAN
LATE MONDAY NIGHT. A MIXTURE OF PRECIPITATION THEN APPEARS POSSIBLE
TUESDAY AND TUESDAY NIGHT AS A GOOD SOUTHERLY FLOW OF MOISTURE AND
WARMTH IS TAPPED. 850MB TEMPERATURES ARE WARM ENOUGH FOR PLAIN RAIN
TUESDAY EVENING ALONG I-94 WITH BOTH THE GFS AND ECMWF SHOWING +5C.
AT THIS POINT HAVE OPTED TO INCLUDE A SNOW...SLEET AND FREEZING RAIN
MIX TO THE SOUTHERN HALF OF THE FORECAST AREA INCLUDING THE I-96
CORRIDOR.

THE TUESDAY SYSTEM IS STILL A LOW CONFIDENCE FORECAST IN TERMS OF
THE FINE DETAILS...HOWEVER THE GFS AND ECMWF HAVE CONVERGED ON THE
SYSTEM SLIDING BY THE AREA ON TUESDAY. THERMAL STRUCTURES ARE
SIMILAR AS WELL. DEPTH AND TRACK OF THE LOW ARE WHAT WE NEED TO
FOCUS ON NOW. THE LOW IS NOT AS DEEP AS PAST RUNS. THE ECWMF IS
STILL SHOWING A 997MB LOW PASSING THROUGH NORTHEAST INDIANA.
PRECIPITATION TOTALS ARE ON THE ORDER OF 0.30 TO 0.60 INCHES.
HEAVIER SNOW SWATH WILL LIKELY BE LOCATED ACROSS THE FORECAST
AREA...AS WILL A POTENTIAL MIX.

OVERALL A FAIRLY ACTIVE PERIOD WITH MODERATING TEMPERATURES. DEEP
ARCTIC AIR IS GONE IN THE LONG TERM AND IS REPLACED BY SOUTHWEST
FLOW AND TEMPS CLOSER TO NORMAL.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1159 PM EST WED FEB 25 2015

OCCASIONAL LIGHT SNOW WILL BRING VSBYS OF 2-4 MILES OVERNIGHT AND
THURSDAY MORNING MAINLY SOUTH AND EAST OF GRR. THE LIGHT SNOW WILL
END BETWEEN 14Z AND 18Z THURSDAY FROM NORTHWEST TO SOUTHEAST.
MAINLY MVFR CONDITIONS TONIGHT AND THURSDAY MORNING SOUTH AND EAST
OF GRR ARE EXPECTED TO IMPROVE TO PRIMARILY VFR CONDITIONS AFTER
18Z THURSDAY.


&&

.HYDROLOGY...
ISSUED AT 310 PM EST WED FEB 25 2015

RIVER LEVELS ARE HOLDING STEADY WELL BELOW BANKFULL WITH ONLY MINOR
FLUCTUATIONS AT SEVERAL SITES. RIVER SURFACES ARE MOSTLY TO ENTIRELY
ICE/SNOW COVERED AND FLOW UNDERNEATH THE ICE DOES NOT APPEAR TO BE
IMPEDED BY ICE JAMS AT ANY GAUGE SITE CURRENTLY. THE RISK OF
FLOODING WILL REMAIN RATHER LIMITED UNTIL A WARM UP OR SIGNIFICANT
RAINFALL COMES AROUND.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&

$$

SYNOPSIS...LAURENS
SHORT TERM...LAURENS
LONG TERM...DUKE
AVIATION...MEADE
HYDROLOGY...CAS











000
FXUS63 KGRR 260827
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
330 AM EST THU FEB 26 2015

LATEST UPDATE...
SYNOPSIS/SHORT TERM/LONG TERM

.SYNOPSIS...
ISSUED AT 330 AM EST THU FEB 26 2015

A FEW LIGHT SNOW SHOWERS AND FLURRIES WILL LINGER ACROSS FAR
SOUTHERN LOWER MICHIGAN THIS MORNING BEFORE HIGH PRESSURE BUILDS
IN TO PRODUCE FAIR BUT COLD WEATHER LATER TODAY THROUGH SATURDAY.
TEMPERATURES WILL FINALLY UNDERGO A GRADUAL MODERATING TREND
SUNDAY INTO EARLY NEXT WEEK.

&&

.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 330 AM EST THU FEB 26 2015

KGRR RADAR TRENDS AND A CONSENSUS OF SHORT RANGE GUIDANCE SUGGESTS
THAT A FEW LIGHT SNOW SHOWERS AND FLURRIES WILL LINGER THIS
MORNING MAINLY SOUTH OF I-96 WITH VERY LIGHT ACCUMULATIONS OF
UNDER AN INCH.

HIGH PRESSURE WILL BUILD IN LATER TODAY THROUGH SATURDAY TO
PRODUCE FAIR BUT VERY COLD WX. MAX TEMPS TODAY WILL ONLY REACH THE
UPPER SINGLE DIGITS TO MIDDLE TEENS.

WIDESPREAD SUB ZERO MIN TEMPS ARE ANTICIPATED TONIGHT AS SKIES
CLEAR AND WINDS GO CALM AND WITH EXPANSIVE SNOW COVER IN PLACE
ACROSS OUR AREA.

MAX TEMPS FRIDAY WILL ONLY REACH THE TEENS IN SPITE OF A FAIR
AMOUNT OF SUN AFTER THE VERY COLD START TO THE DAY. IT WILL BE
VERY COLD FRIDAY NIGHT AS WELL BUT NOT QUITE AS COLD AS TONIGHT
WITH MIN TEMPS GENERALLY IN THE FIVE BELOW TO FIVE ABOVE ZERO RANGE.

A CONSENSUS OF 00Z TIME HEIGHT RH PROGS SUGGESTS THERE WILL BE
PLENTY OF SUN ON SATURDAY. HOWEVER MAX TEMPS SATURDAY WILL ONLY
REACH THE UPPER TEENS TO LOWER 20S.

WIND SPEEDS TONIGHT WILL BE CALM TO LESS THAN 5 MPH. APPARENT
TEMP READINGS MAY FLIRT WITH -15 ACROSS OUR NORTHERN COUNTIES
DURING THE EARLY MORNING HOURS FRIDAY. HOWEVER GIVEN VERY LITTLE
TO NO WIND OVERNIGHT WIND CHILL ADVISORY CRITERIA WILL LIKELY NOT
BE ATTAINED.

.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 330 AM EST THU FEB 26 2015

FELT YESTERDAY AFTERNOON/S LONG TERM DISCUSSION HAD A VERY GOOD
DESCRIPTION AND HANDLE ON THE EXTENDED PERIODS. DID NOT DEVIATE MUCH
FROM THAT THINKING AS THERE WERE NO REAL SURPRISES IN THE EVENING
MODEL RUNS.

THERE ARE STILL TWO MAIN SYSTEMS TO FOCUS ON IN THE LONG TERM...THE
SNOW EVENT FOR LATE SATURDAY NIGHT THROUGH SUNDAY EVENING AND THE
SYSTEM CENTERED ON NEXT TUESDAY.

THE SUNDAY SNOW EVENT HAS BEEN VERY STEADY IN REGARD TO TIMING AND
AMOUNTS. SNOW TOTALS RANGE FROM 1-2 INCHES UP TOWARDS U.S. 10...TO
3-6 INCHES TOWARDS I-94. THE SNOW IS GENERATED VIA UPPER LEVEL
DIVERGENCE ASSOCIATED WITH A STRONG JET STREAK...LOW LEVEL
ISENTROPIC RESPONSE AND A WEAK FRONTAL ZONE. MODELS HAVE BEEN
CONSISTENT WITH AMOUNTS FROM RUN TO RUN AND MODEL TO MODEL...SO
CONFIDENCE IN THE SATURDAY NIGHT THROUGH SUNDAY NIGHT SNOW IS FAIRLY
HIGH.

FOCUS THEN SHIFTS TO A LOW THAT DEVELOPS IN THE LEE OF THE ROCKIES
IN SOUTHEAST COLORADO ON MONDAY. THE LOW MOVES NORTHEAST TOWARDS THE
GREAT LAKES AND SHOULD SPREAD SNOW INTO SOUTHWEST LOWER MICHIGAN
LATE MONDAY NIGHT. A MIXTURE OF PRECIPITATION THEN APPEARS POSSIBLE
TUESDAY AND TUESDAY NIGHT AS A GOOD SOUTHERLY FLOW OF MOISTURE AND
WARMTH IS TAPPED. 850MB TEMPERATURES ARE WARM ENOUGH FOR PLAIN RAIN
TUESDAY EVENING ALONG I-94 WITH BOTH THE GFS AND ECMWF SHOWING +5C.
AT THIS POINT HAVE OPTED TO INCLUDE A SNOW...SLEET AND FREEZING RAIN
MIX TO THE SOUTHERN HALF OF THE FORECAST AREA INCLUDING THE I-96
CORRIDOR.

THE TUESDAY SYSTEM IS STILL A LOW CONFIDENCE FORECAST IN TERMS OF
THE FINE DETAILS...HOWEVER THE GFS AND ECMWF HAVE CONVERGED ON THE
SYSTEM SLIDING BY THE AREA ON TUESDAY. THERMAL STRUCTURES ARE
SIMILAR AS WELL. DEPTH AND TRACK OF THE LOW ARE WHAT WE NEED TO
FOCUS ON NOW. THE LOW IS NOT AS DEEP AS PAST RUNS. THE ECWMF IS
STILL SHOWING A 997MB LOW PASSING THROUGH NORTHEAST INDIANA.
PRECIPITATION TOTALS ARE ON THE ORDER OF 0.30 TO 0.60 INCHES.
HEAVIER SNOW SWATH WILL LIKELY BE LOCATED ACROSS THE FORECAST
AREA...AS WILL A POTENTIAL MIX.

OVERALL A FAIRLY ACTIVE PERIOD WITH MODERATING TEMPERATURES. DEEP
ARCTIC AIR IS GONE IN THE LONG TERM AND IS REPLACED BY SOUTHWEST
FLOW AND TEMPS CLOSER TO NORMAL.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1159 PM EST WED FEB 25 2015

OCCASIONAL LIGHT SNOW WILL BRING VSBYS OF 2-4 MILES OVERNIGHT AND
THURSDAY MORNING MAINLY SOUTH AND EAST OF GRR. THE LIGHT SNOW WILL
END BETWEEN 14Z AND 18Z THURSDAY FROM NORTHWEST TO SOUTHEAST.
MAINLY MVFR CONDITIONS TONIGHT AND THURSDAY MORNING SOUTH AND EAST
OF GRR ARE EXPECTED TO IMPROVE TO PRIMARILY VFR CONDITIONS AFTER
18Z THURSDAY.


&&

.HYDROLOGY...
ISSUED AT 310 PM EST WED FEB 25 2015

RIVER LEVELS ARE HOLDING STEADY WELL BELOW BANKFULL WITH ONLY MINOR
FLUCTUATIONS AT SEVERAL SITES. RIVER SURFACES ARE MOSTLY TO ENTIRELY
ICE/SNOW COVERED AND FLOW UNDERNEATH THE ICE DOES NOT APPEAR TO BE
IMPEDED BY ICE JAMS AT ANY GAUGE SITE CURRENTLY. THE RISK OF
FLOODING WILL REMAIN RATHER LIMITED UNTIL A WARM UP OR SIGNIFICANT
RAINFALL COMES AROUND.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&

$$

SYNOPSIS...LAURENS
SHORT TERM...LAURENS
LONG TERM...DUKE
AVIATION...MEADE
HYDROLOGY...CAS










000
FXUS63 KGRR 260501
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1201 AM EST THU FEB 26 2015

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 310 PM EST WED FEB 25 2015

A SYSTEM PASSING SOUTH OF MICHIGAN WILL BRING LIGHT SNOW TO THE
AREA FROM LATER THIS EVENING INTO EARLY THURSDAY. A LARGE POLAR
HIGH PRESSURE SYSTEM WILL THEN CONTROL THE WEATHER OVER SOUTHWEST
MICHIGAN THROUGH SATURDAY MORNING. VERY COLD TEMPERATURES ARE
EXPECTED THROUGH SATURDAY MORNING. A SLOW WARMING TREND BEGINS
SATURDAY. BY SUNDAY ENOUGH MOISTURE REACHES MICHIGAN TO BRING SNOW
TO THE AREA AS A WEAK SYSTEM PASSES WELL SOUTH OF MICHIGAN.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 310 PM EST WED FEB 25 2015

I EXPECT LIGHT SNOW TO DEVELOP NEAR INTERSTATE 96 IN A NARROW BAND LATE
THIS EVENING (AROUND 10 PM OR SO). THAT NARROW AREA OF LIGHT SNOW
WILL SLOWLY SPREAD SOUTH AND MERGE WITH AN AREA OF SNOW MOVING
SOUTHEAST FROM WISCONSIN AND ILLINOIS AFTER MIDNIGHT AS I HEADS
TOWARD INTERSTATE 94. SNOWFALL FROM THIS EVENT WILL BE
LIGHT...MOSTLY AND INCH OR LESS. ARCTIC HIGH PRESSURE BUILDS IN
BEHIND THE SYSTEM FOR THURSDAY NIGHT INTO FRIDAY NIGHT SO FOR THE
MOST PART IT WILL JUST BE VERY COLD. WE MAY NEED WIND CHILL
HEADLINES THURSDAY NIGHT AND FRIDAY NIGHT.

THE SYSTEM THIS EVENING IS RATHER CURIOUS IN THAT EVEN THOUGH THE
PRIMARY SYSTEM PASSES WELL SOUTH AND WEST OF MICHIGAN TONIGHT...
BEING UNDER JET EXIT REGION WE STILL GET DEEP LIFT OVER MOST OF
SOUTHWEST LOWER MICHIGAN DURING THE LATE EVENING AND EARLY MORNING
HOURS. DURING THIS TIME THE DGZ IS RATHER DEEP AND NEARLY
SATURATED FROM NEAR THE SURFACE TO 12,000 FT AT MIDNIGHT.
MEANWHILE WE GET A DIFFERENTIAL COOLING BOUNDARY THAT SETS UP JUST
NORTH OF INTERSTATE 96 WHICH RESULTS IN A SURFACE FGEN BAND THAT
MOVES NEARLY DUE SOUTH FROM INTERSTATE 96 AT AROUND MIDNIGHT TO
NEAR INTERSTATE 94 BY 4-5 AM OR SO. WHEN THE JUXTAPOSITION OF THE
DEEP (WEAK )LIFT AND THE SURFACE FGEN COME TOGETHER WE GET A
NARROW BAND OF SNOW SHOWERS NEAR INTERSTATE 96 AS A RESULT (BY
MIDNIGHT). THIS AREA WILL SLOWLY MOVE SOUTH OVER TIME...MERGING
WITH THE SYSTEM PASSING SOUTH OF MICHIGAN BY MORNING. MOST AREAS
WILL SEE LESS THAN AN INCH OF SNOW FROM THIS EVENT.

ALL OF THIS MOVES OUT BY MID MORNING THURSDAY AND THAT ALLOW A
LARGE POLAR HIGH TO BUILD IN WITH MOSTLY NORTHERLY SURFACE WINDS.
THAT WILL KEEP ANY LAKE EFFECT SNOW BANDS OFF SHORE TOMORROW. WITH
NEARLY CLEAR SKIES THURSDAY NIGHT INTO FRIDAY MORNING TEMPERATURES
IN MOST AREAS WILL FALL TO BETWEEN 5 AND 25 BELOW ZERO. LIKELY WE
WILL NEED A WIND CHILL ADVISORY FOR THAT.

.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 310 PM EST WED FEB 25 2015

TWO ITEMS OF INTEREST REMAIN IN THE LONG TERM PORTION OF THE FCST.
THESE ITEMS ARE SYSTEMS THAT WILL POTENTIALLY BRING SOME
ACCUMULATING SNOW TO THE AREA. A PATTERN SHIFT IS STILL EXPECTED
WHERE WILL WILL NOT BE SEEING WAVES OF BRUTALLY COLD AIR AS MUCH AS
THE PAST FEW WEEKS.

THE FIRST POTENTIAL OF ACCUMULATING SNOW WILL COME DURING THE SAT
NIGHT/SUN TIME FRAME AFTER A QUIET SAT. THE EXACT TIMING AND
POSITION IS A LITTLE UNCERTAIN YET. IT DOES APPEAR IT WILL BE
CENTERED AROUND THE LATTER PART OF SAT NIGHT TO SUN MORNING. AS
MENTIONED BEFORE...WE DO NOT SEE MUCH OF AN UPPER WAVE OR SFC
REFLECTION OF A LOW. INSTEAD...WE WILL BECOME UNDER THE INFLUENCE OF
THE LFQ REGION OF A DEVELOPING UPPER JET STREAK DOWNSTREAM OF THE
UPPER LOW DIGGING ACROSS THE SW. IN ADDITION...WE WILL SEE AN INFLUX
OF LOW LEVEL MOISTURE ADVECT IN WITH RETURN FLOW TAPPING THE GULF.

WE WILL SEE A RELATIVELY QUIET PERIOD ON SUN NIGHT THROUGH MON NIGHT
WITH SOMEWHAT MILDER TEMPS HIGH PRESSURE WILL CONTROL THE WEATHER
FROM SUN NIGHT THROUGH MON NIGHT. THERE IS A SMALL CHC OF SOME LAKE
EFFECT NEAR THE LAKESHORE THOSE DAYS. THE OVER LAKE INSTABILITY IS
MARGINAL WITH H850 TEMPS ONLY AROUND -10C OR SO. THE NRN BRANCH OF
THE JET IS NEVER REALLY EXPECTED TO DROP SOUTH OF THE AREA. THIS
WILL KEEP INVERSION HEIGHTS LOW WITH LIMITED MOISTURE DEPTH.

THE SECOND SYSTEM OF INTEREST WILL BE COMING IN FOR THE PERIOD ON
TUE/TUE NIGHT NEXT WEEK. A LOT OF UNCERTAINTY REMAINS WITH THIS
SYSTEM WITH REGARDS TO PCPN AMOUNTS...P-TYPE...AND TIMING. WE WILL
BE SEEING A PIECE OF ENERGY EJECT FROM THE DEVELOPING SW U.S. LOW
AND HEADING TOWARD THE AREA. AT THE SAME TIME...A NRN STREAM SYSTEM
WILL MOVE TOWARD THE AREA. THE BIG UNCERTAINTY COME WITH HOW
MUCH...IF ANY PHASING TAKES PLACE. NOT REALLY A LOT OF RUN-TO-RUN
CONTINUITY WITH THIS SYSTEM. IF IT PHASES...WE COULD SEE A LOT MORE
PCPN WITH MIXED P-TYPES. IF IT REMAINS UNPHASED...WE WILL SEE LESS
PCPN AND SNOW AS THE MAIN P-TYPE.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1159 PM EST WED FEB 25 2015

OCCASIONAL LIGHT SNOW WILL BRING VSBYS OF 2-4 MILES OVERNIGHT AND
THURSDAY MORNING MAINLY SOUTH AND EAST OF GRR. THE LIGHT SNOW WILL
END BETWEEN 14Z AND 18Z THURSDAY FROM NORTHWEST TO SOUTHEAST.
MAINLY MVFR CONDITIONS TONIGHT AND THURSDAY MORNING SOUTH AND EAST
OF GRR ARE EXPECTED TO IMPROVE TO PRIMARILY VFR CONDITIONS AFTER
18Z THURSDAY.

&&

.HYDROLOGY...
ISSUED AT 310 PM EST WED FEB 25 2015

RIVER LEVELS ARE HOLDING STEADY WELL BELOW BANKFULL WITH ONLY MINOR
FLUCTUATIONS AT SEVERAL SITES. RIVER SURFACES ARE MOSTLY TO ENTIRELY
ICE/SNOW COVERED AND FLOW UNDERNEATH THE ICE DOES NOT APPEAR TO BE
IMPEDED BY ICE JAMS AT ANY GAUGE SITE CURRENTLY. THE RISK OF
FLOODING WILL REMAIN RATHER LIMITED UNTIL A WARM UP OR SIGNIFICANT
RAINFALL COMES AROUND.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&

$$

SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...NJJ
AVIATION...MEADE
HYDROLOGY...CAS







000
FXUS63 KGRR 260501
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1201 AM EST THU FEB 26 2015

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 310 PM EST WED FEB 25 2015

A SYSTEM PASSING SOUTH OF MICHIGAN WILL BRING LIGHT SNOW TO THE
AREA FROM LATER THIS EVENING INTO EARLY THURSDAY. A LARGE POLAR
HIGH PRESSURE SYSTEM WILL THEN CONTROL THE WEATHER OVER SOUTHWEST
MICHIGAN THROUGH SATURDAY MORNING. VERY COLD TEMPERATURES ARE
EXPECTED THROUGH SATURDAY MORNING. A SLOW WARMING TREND BEGINS
SATURDAY. BY SUNDAY ENOUGH MOISTURE REACHES MICHIGAN TO BRING SNOW
TO THE AREA AS A WEAK SYSTEM PASSES WELL SOUTH OF MICHIGAN.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 310 PM EST WED FEB 25 2015

I EXPECT LIGHT SNOW TO DEVELOP NEAR INTERSTATE 96 IN A NARROW BAND LATE
THIS EVENING (AROUND 10 PM OR SO). THAT NARROW AREA OF LIGHT SNOW
WILL SLOWLY SPREAD SOUTH AND MERGE WITH AN AREA OF SNOW MOVING
SOUTHEAST FROM WISCONSIN AND ILLINOIS AFTER MIDNIGHT AS I HEADS
TOWARD INTERSTATE 94. SNOWFALL FROM THIS EVENT WILL BE
LIGHT...MOSTLY AND INCH OR LESS. ARCTIC HIGH PRESSURE BUILDS IN
BEHIND THE SYSTEM FOR THURSDAY NIGHT INTO FRIDAY NIGHT SO FOR THE
MOST PART IT WILL JUST BE VERY COLD. WE MAY NEED WIND CHILL
HEADLINES THURSDAY NIGHT AND FRIDAY NIGHT.

THE SYSTEM THIS EVENING IS RATHER CURIOUS IN THAT EVEN THOUGH THE
PRIMARY SYSTEM PASSES WELL SOUTH AND WEST OF MICHIGAN TONIGHT...
BEING UNDER JET EXIT REGION WE STILL GET DEEP LIFT OVER MOST OF
SOUTHWEST LOWER MICHIGAN DURING THE LATE EVENING AND EARLY MORNING
HOURS. DURING THIS TIME THE DGZ IS RATHER DEEP AND NEARLY
SATURATED FROM NEAR THE SURFACE TO 12,000 FT AT MIDNIGHT.
MEANWHILE WE GET A DIFFERENTIAL COOLING BOUNDARY THAT SETS UP JUST
NORTH OF INTERSTATE 96 WHICH RESULTS IN A SURFACE FGEN BAND THAT
MOVES NEARLY DUE SOUTH FROM INTERSTATE 96 AT AROUND MIDNIGHT TO
NEAR INTERSTATE 94 BY 4-5 AM OR SO. WHEN THE JUXTAPOSITION OF THE
DEEP (WEAK )LIFT AND THE SURFACE FGEN COME TOGETHER WE GET A
NARROW BAND OF SNOW SHOWERS NEAR INTERSTATE 96 AS A RESULT (BY
MIDNIGHT). THIS AREA WILL SLOWLY MOVE SOUTH OVER TIME...MERGING
WITH THE SYSTEM PASSING SOUTH OF MICHIGAN BY MORNING. MOST AREAS
WILL SEE LESS THAN AN INCH OF SNOW FROM THIS EVENT.

ALL OF THIS MOVES OUT BY MID MORNING THURSDAY AND THAT ALLOW A
LARGE POLAR HIGH TO BUILD IN WITH MOSTLY NORTHERLY SURFACE WINDS.
THAT WILL KEEP ANY LAKE EFFECT SNOW BANDS OFF SHORE TOMORROW. WITH
NEARLY CLEAR SKIES THURSDAY NIGHT INTO FRIDAY MORNING TEMPERATURES
IN MOST AREAS WILL FALL TO BETWEEN 5 AND 25 BELOW ZERO. LIKELY WE
WILL NEED A WIND CHILL ADVISORY FOR THAT.

.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 310 PM EST WED FEB 25 2015

TWO ITEMS OF INTEREST REMAIN IN THE LONG TERM PORTION OF THE FCST.
THESE ITEMS ARE SYSTEMS THAT WILL POTENTIALLY BRING SOME
ACCUMULATING SNOW TO THE AREA. A PATTERN SHIFT IS STILL EXPECTED
WHERE WILL WILL NOT BE SEEING WAVES OF BRUTALLY COLD AIR AS MUCH AS
THE PAST FEW WEEKS.

THE FIRST POTENTIAL OF ACCUMULATING SNOW WILL COME DURING THE SAT
NIGHT/SUN TIME FRAME AFTER A QUIET SAT. THE EXACT TIMING AND
POSITION IS A LITTLE UNCERTAIN YET. IT DOES APPEAR IT WILL BE
CENTERED AROUND THE LATTER PART OF SAT NIGHT TO SUN MORNING. AS
MENTIONED BEFORE...WE DO NOT SEE MUCH OF AN UPPER WAVE OR SFC
REFLECTION OF A LOW. INSTEAD...WE WILL BECOME UNDER THE INFLUENCE OF
THE LFQ REGION OF A DEVELOPING UPPER JET STREAK DOWNSTREAM OF THE
UPPER LOW DIGGING ACROSS THE SW. IN ADDITION...WE WILL SEE AN INFLUX
OF LOW LEVEL MOISTURE ADVECT IN WITH RETURN FLOW TAPPING THE GULF.

WE WILL SEE A RELATIVELY QUIET PERIOD ON SUN NIGHT THROUGH MON NIGHT
WITH SOMEWHAT MILDER TEMPS HIGH PRESSURE WILL CONTROL THE WEATHER
FROM SUN NIGHT THROUGH MON NIGHT. THERE IS A SMALL CHC OF SOME LAKE
EFFECT NEAR THE LAKESHORE THOSE DAYS. THE OVER LAKE INSTABILITY IS
MARGINAL WITH H850 TEMPS ONLY AROUND -10C OR SO. THE NRN BRANCH OF
THE JET IS NEVER REALLY EXPECTED TO DROP SOUTH OF THE AREA. THIS
WILL KEEP INVERSION HEIGHTS LOW WITH LIMITED MOISTURE DEPTH.

THE SECOND SYSTEM OF INTEREST WILL BE COMING IN FOR THE PERIOD ON
TUE/TUE NIGHT NEXT WEEK. A LOT OF UNCERTAINTY REMAINS WITH THIS
SYSTEM WITH REGARDS TO PCPN AMOUNTS...P-TYPE...AND TIMING. WE WILL
BE SEEING A PIECE OF ENERGY EJECT FROM THE DEVELOPING SW U.S. LOW
AND HEADING TOWARD THE AREA. AT THE SAME TIME...A NRN STREAM SYSTEM
WILL MOVE TOWARD THE AREA. THE BIG UNCERTAINTY COME WITH HOW
MUCH...IF ANY PHASING TAKES PLACE. NOT REALLY A LOT OF RUN-TO-RUN
CONTINUITY WITH THIS SYSTEM. IF IT PHASES...WE COULD SEE A LOT MORE
PCPN WITH MIXED P-TYPES. IF IT REMAINS UNPHASED...WE WILL SEE LESS
PCPN AND SNOW AS THE MAIN P-TYPE.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1159 PM EST WED FEB 25 2015

OCCASIONAL LIGHT SNOW WILL BRING VSBYS OF 2-4 MILES OVERNIGHT AND
THURSDAY MORNING MAINLY SOUTH AND EAST OF GRR. THE LIGHT SNOW WILL
END BETWEEN 14Z AND 18Z THURSDAY FROM NORTHWEST TO SOUTHEAST.
MAINLY MVFR CONDITIONS TONIGHT AND THURSDAY MORNING SOUTH AND EAST
OF GRR ARE EXPECTED TO IMPROVE TO PRIMARILY VFR CONDITIONS AFTER
18Z THURSDAY.

&&

.HYDROLOGY...
ISSUED AT 310 PM EST WED FEB 25 2015

RIVER LEVELS ARE HOLDING STEADY WELL BELOW BANKFULL WITH ONLY MINOR
FLUCTUATIONS AT SEVERAL SITES. RIVER SURFACES ARE MOSTLY TO ENTIRELY
ICE/SNOW COVERED AND FLOW UNDERNEATH THE ICE DOES NOT APPEAR TO BE
IMPEDED BY ICE JAMS AT ANY GAUGE SITE CURRENTLY. THE RISK OF
FLOODING WILL REMAIN RATHER LIMITED UNTIL A WARM UP OR SIGNIFICANT
RAINFALL COMES AROUND.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&

$$

SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...NJJ
AVIATION...MEADE
HYDROLOGY...CAS








000
FXUS63 KGRR 260501
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1201 AM EST THU FEB 26 2015

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 310 PM EST WED FEB 25 2015

A SYSTEM PASSING SOUTH OF MICHIGAN WILL BRING LIGHT SNOW TO THE
AREA FROM LATER THIS EVENING INTO EARLY THURSDAY. A LARGE POLAR
HIGH PRESSURE SYSTEM WILL THEN CONTROL THE WEATHER OVER SOUTHWEST
MICHIGAN THROUGH SATURDAY MORNING. VERY COLD TEMPERATURES ARE
EXPECTED THROUGH SATURDAY MORNING. A SLOW WARMING TREND BEGINS
SATURDAY. BY SUNDAY ENOUGH MOISTURE REACHES MICHIGAN TO BRING SNOW
TO THE AREA AS A WEAK SYSTEM PASSES WELL SOUTH OF MICHIGAN.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 310 PM EST WED FEB 25 2015

I EXPECT LIGHT SNOW TO DEVELOP NEAR INTERSTATE 96 IN A NARROW BAND LATE
THIS EVENING (AROUND 10 PM OR SO). THAT NARROW AREA OF LIGHT SNOW
WILL SLOWLY SPREAD SOUTH AND MERGE WITH AN AREA OF SNOW MOVING
SOUTHEAST FROM WISCONSIN AND ILLINOIS AFTER MIDNIGHT AS I HEADS
TOWARD INTERSTATE 94. SNOWFALL FROM THIS EVENT WILL BE
LIGHT...MOSTLY AND INCH OR LESS. ARCTIC HIGH PRESSURE BUILDS IN
BEHIND THE SYSTEM FOR THURSDAY NIGHT INTO FRIDAY NIGHT SO FOR THE
MOST PART IT WILL JUST BE VERY COLD. WE MAY NEED WIND CHILL
HEADLINES THURSDAY NIGHT AND FRIDAY NIGHT.

THE SYSTEM THIS EVENING IS RATHER CURIOUS IN THAT EVEN THOUGH THE
PRIMARY SYSTEM PASSES WELL SOUTH AND WEST OF MICHIGAN TONIGHT...
BEING UNDER JET EXIT REGION WE STILL GET DEEP LIFT OVER MOST OF
SOUTHWEST LOWER MICHIGAN DURING THE LATE EVENING AND EARLY MORNING
HOURS. DURING THIS TIME THE DGZ IS RATHER DEEP AND NEARLY
SATURATED FROM NEAR THE SURFACE TO 12,000 FT AT MIDNIGHT.
MEANWHILE WE GET A DIFFERENTIAL COOLING BOUNDARY THAT SETS UP JUST
NORTH OF INTERSTATE 96 WHICH RESULTS IN A SURFACE FGEN BAND THAT
MOVES NEARLY DUE SOUTH FROM INTERSTATE 96 AT AROUND MIDNIGHT TO
NEAR INTERSTATE 94 BY 4-5 AM OR SO. WHEN THE JUXTAPOSITION OF THE
DEEP (WEAK )LIFT AND THE SURFACE FGEN COME TOGETHER WE GET A
NARROW BAND OF SNOW SHOWERS NEAR INTERSTATE 96 AS A RESULT (BY
MIDNIGHT). THIS AREA WILL SLOWLY MOVE SOUTH OVER TIME...MERGING
WITH THE SYSTEM PASSING SOUTH OF MICHIGAN BY MORNING. MOST AREAS
WILL SEE LESS THAN AN INCH OF SNOW FROM THIS EVENT.

ALL OF THIS MOVES OUT BY MID MORNING THURSDAY AND THAT ALLOW A
LARGE POLAR HIGH TO BUILD IN WITH MOSTLY NORTHERLY SURFACE WINDS.
THAT WILL KEEP ANY LAKE EFFECT SNOW BANDS OFF SHORE TOMORROW. WITH
NEARLY CLEAR SKIES THURSDAY NIGHT INTO FRIDAY MORNING TEMPERATURES
IN MOST AREAS WILL FALL TO BETWEEN 5 AND 25 BELOW ZERO. LIKELY WE
WILL NEED A WIND CHILL ADVISORY FOR THAT.

.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 310 PM EST WED FEB 25 2015

TWO ITEMS OF INTEREST REMAIN IN THE LONG TERM PORTION OF THE FCST.
THESE ITEMS ARE SYSTEMS THAT WILL POTENTIALLY BRING SOME
ACCUMULATING SNOW TO THE AREA. A PATTERN SHIFT IS STILL EXPECTED
WHERE WILL WILL NOT BE SEEING WAVES OF BRUTALLY COLD AIR AS MUCH AS
THE PAST FEW WEEKS.

THE FIRST POTENTIAL OF ACCUMULATING SNOW WILL COME DURING THE SAT
NIGHT/SUN TIME FRAME AFTER A QUIET SAT. THE EXACT TIMING AND
POSITION IS A LITTLE UNCERTAIN YET. IT DOES APPEAR IT WILL BE
CENTERED AROUND THE LATTER PART OF SAT NIGHT TO SUN MORNING. AS
MENTIONED BEFORE...WE DO NOT SEE MUCH OF AN UPPER WAVE OR SFC
REFLECTION OF A LOW. INSTEAD...WE WILL BECOME UNDER THE INFLUENCE OF
THE LFQ REGION OF A DEVELOPING UPPER JET STREAK DOWNSTREAM OF THE
UPPER LOW DIGGING ACROSS THE SW. IN ADDITION...WE WILL SEE AN INFLUX
OF LOW LEVEL MOISTURE ADVECT IN WITH RETURN FLOW TAPPING THE GULF.

WE WILL SEE A RELATIVELY QUIET PERIOD ON SUN NIGHT THROUGH MON NIGHT
WITH SOMEWHAT MILDER TEMPS HIGH PRESSURE WILL CONTROL THE WEATHER
FROM SUN NIGHT THROUGH MON NIGHT. THERE IS A SMALL CHC OF SOME LAKE
EFFECT NEAR THE LAKESHORE THOSE DAYS. THE OVER LAKE INSTABILITY IS
MARGINAL WITH H850 TEMPS ONLY AROUND -10C OR SO. THE NRN BRANCH OF
THE JET IS NEVER REALLY EXPECTED TO DROP SOUTH OF THE AREA. THIS
WILL KEEP INVERSION HEIGHTS LOW WITH LIMITED MOISTURE DEPTH.

THE SECOND SYSTEM OF INTEREST WILL BE COMING IN FOR THE PERIOD ON
TUE/TUE NIGHT NEXT WEEK. A LOT OF UNCERTAINTY REMAINS WITH THIS
SYSTEM WITH REGARDS TO PCPN AMOUNTS...P-TYPE...AND TIMING. WE WILL
BE SEEING A PIECE OF ENERGY EJECT FROM THE DEVELOPING SW U.S. LOW
AND HEADING TOWARD THE AREA. AT THE SAME TIME...A NRN STREAM SYSTEM
WILL MOVE TOWARD THE AREA. THE BIG UNCERTAINTY COME WITH HOW
MUCH...IF ANY PHASING TAKES PLACE. NOT REALLY A LOT OF RUN-TO-RUN
CONTINUITY WITH THIS SYSTEM. IF IT PHASES...WE COULD SEE A LOT MORE
PCPN WITH MIXED P-TYPES. IF IT REMAINS UNPHASED...WE WILL SEE LESS
PCPN AND SNOW AS THE MAIN P-TYPE.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1159 PM EST WED FEB 25 2015

OCCASIONAL LIGHT SNOW WILL BRING VSBYS OF 2-4 MILES OVERNIGHT AND
THURSDAY MORNING MAINLY SOUTH AND EAST OF GRR. THE LIGHT SNOW WILL
END BETWEEN 14Z AND 18Z THURSDAY FROM NORTHWEST TO SOUTHEAST.
MAINLY MVFR CONDITIONS TONIGHT AND THURSDAY MORNING SOUTH AND EAST
OF GRR ARE EXPECTED TO IMPROVE TO PRIMARILY VFR CONDITIONS AFTER
18Z THURSDAY.

&&

.HYDROLOGY...
ISSUED AT 310 PM EST WED FEB 25 2015

RIVER LEVELS ARE HOLDING STEADY WELL BELOW BANKFULL WITH ONLY MINOR
FLUCTUATIONS AT SEVERAL SITES. RIVER SURFACES ARE MOSTLY TO ENTIRELY
ICE/SNOW COVERED AND FLOW UNDERNEATH THE ICE DOES NOT APPEAR TO BE
IMPEDED BY ICE JAMS AT ANY GAUGE SITE CURRENTLY. THE RISK OF
FLOODING WILL REMAIN RATHER LIMITED UNTIL A WARM UP OR SIGNIFICANT
RAINFALL COMES AROUND.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&

$$

SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...NJJ
AVIATION...MEADE
HYDROLOGY...CAS







000
FXUS63 KGRR 260501
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1201 AM EST THU FEB 26 2015

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 310 PM EST WED FEB 25 2015

A SYSTEM PASSING SOUTH OF MICHIGAN WILL BRING LIGHT SNOW TO THE
AREA FROM LATER THIS EVENING INTO EARLY THURSDAY. A LARGE POLAR
HIGH PRESSURE SYSTEM WILL THEN CONTROL THE WEATHER OVER SOUTHWEST
MICHIGAN THROUGH SATURDAY MORNING. VERY COLD TEMPERATURES ARE
EXPECTED THROUGH SATURDAY MORNING. A SLOW WARMING TREND BEGINS
SATURDAY. BY SUNDAY ENOUGH MOISTURE REACHES MICHIGAN TO BRING SNOW
TO THE AREA AS A WEAK SYSTEM PASSES WELL SOUTH OF MICHIGAN.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 310 PM EST WED FEB 25 2015

I EXPECT LIGHT SNOW TO DEVELOP NEAR INTERSTATE 96 IN A NARROW BAND LATE
THIS EVENING (AROUND 10 PM OR SO). THAT NARROW AREA OF LIGHT SNOW
WILL SLOWLY SPREAD SOUTH AND MERGE WITH AN AREA OF SNOW MOVING
SOUTHEAST FROM WISCONSIN AND ILLINOIS AFTER MIDNIGHT AS I HEADS
TOWARD INTERSTATE 94. SNOWFALL FROM THIS EVENT WILL BE
LIGHT...MOSTLY AND INCH OR LESS. ARCTIC HIGH PRESSURE BUILDS IN
BEHIND THE SYSTEM FOR THURSDAY NIGHT INTO FRIDAY NIGHT SO FOR THE
MOST PART IT WILL JUST BE VERY COLD. WE MAY NEED WIND CHILL
HEADLINES THURSDAY NIGHT AND FRIDAY NIGHT.

THE SYSTEM THIS EVENING IS RATHER CURIOUS IN THAT EVEN THOUGH THE
PRIMARY SYSTEM PASSES WELL SOUTH AND WEST OF MICHIGAN TONIGHT...
BEING UNDER JET EXIT REGION WE STILL GET DEEP LIFT OVER MOST OF
SOUTHWEST LOWER MICHIGAN DURING THE LATE EVENING AND EARLY MORNING
HOURS. DURING THIS TIME THE DGZ IS RATHER DEEP AND NEARLY
SATURATED FROM NEAR THE SURFACE TO 12,000 FT AT MIDNIGHT.
MEANWHILE WE GET A DIFFERENTIAL COOLING BOUNDARY THAT SETS UP JUST
NORTH OF INTERSTATE 96 WHICH RESULTS IN A SURFACE FGEN BAND THAT
MOVES NEARLY DUE SOUTH FROM INTERSTATE 96 AT AROUND MIDNIGHT TO
NEAR INTERSTATE 94 BY 4-5 AM OR SO. WHEN THE JUXTAPOSITION OF THE
DEEP (WEAK )LIFT AND THE SURFACE FGEN COME TOGETHER WE GET A
NARROW BAND OF SNOW SHOWERS NEAR INTERSTATE 96 AS A RESULT (BY
MIDNIGHT). THIS AREA WILL SLOWLY MOVE SOUTH OVER TIME...MERGING
WITH THE SYSTEM PASSING SOUTH OF MICHIGAN BY MORNING. MOST AREAS
WILL SEE LESS THAN AN INCH OF SNOW FROM THIS EVENT.

ALL OF THIS MOVES OUT BY MID MORNING THURSDAY AND THAT ALLOW A
LARGE POLAR HIGH TO BUILD IN WITH MOSTLY NORTHERLY SURFACE WINDS.
THAT WILL KEEP ANY LAKE EFFECT SNOW BANDS OFF SHORE TOMORROW. WITH
NEARLY CLEAR SKIES THURSDAY NIGHT INTO FRIDAY MORNING TEMPERATURES
IN MOST AREAS WILL FALL TO BETWEEN 5 AND 25 BELOW ZERO. LIKELY WE
WILL NEED A WIND CHILL ADVISORY FOR THAT.

.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 310 PM EST WED FEB 25 2015

TWO ITEMS OF INTEREST REMAIN IN THE LONG TERM PORTION OF THE FCST.
THESE ITEMS ARE SYSTEMS THAT WILL POTENTIALLY BRING SOME
ACCUMULATING SNOW TO THE AREA. A PATTERN SHIFT IS STILL EXPECTED
WHERE WILL WILL NOT BE SEEING WAVES OF BRUTALLY COLD AIR AS MUCH AS
THE PAST FEW WEEKS.

THE FIRST POTENTIAL OF ACCUMULATING SNOW WILL COME DURING THE SAT
NIGHT/SUN TIME FRAME AFTER A QUIET SAT. THE EXACT TIMING AND
POSITION IS A LITTLE UNCERTAIN YET. IT DOES APPEAR IT WILL BE
CENTERED AROUND THE LATTER PART OF SAT NIGHT TO SUN MORNING. AS
MENTIONED BEFORE...WE DO NOT SEE MUCH OF AN UPPER WAVE OR SFC
REFLECTION OF A LOW. INSTEAD...WE WILL BECOME UNDER THE INFLUENCE OF
THE LFQ REGION OF A DEVELOPING UPPER JET STREAK DOWNSTREAM OF THE
UPPER LOW DIGGING ACROSS THE SW. IN ADDITION...WE WILL SEE AN INFLUX
OF LOW LEVEL MOISTURE ADVECT IN WITH RETURN FLOW TAPPING THE GULF.

WE WILL SEE A RELATIVELY QUIET PERIOD ON SUN NIGHT THROUGH MON NIGHT
WITH SOMEWHAT MILDER TEMPS HIGH PRESSURE WILL CONTROL THE WEATHER
FROM SUN NIGHT THROUGH MON NIGHT. THERE IS A SMALL CHC OF SOME LAKE
EFFECT NEAR THE LAKESHORE THOSE DAYS. THE OVER LAKE INSTABILITY IS
MARGINAL WITH H850 TEMPS ONLY AROUND -10C OR SO. THE NRN BRANCH OF
THE JET IS NEVER REALLY EXPECTED TO DROP SOUTH OF THE AREA. THIS
WILL KEEP INVERSION HEIGHTS LOW WITH LIMITED MOISTURE DEPTH.

THE SECOND SYSTEM OF INTEREST WILL BE COMING IN FOR THE PERIOD ON
TUE/TUE NIGHT NEXT WEEK. A LOT OF UNCERTAINTY REMAINS WITH THIS
SYSTEM WITH REGARDS TO PCPN AMOUNTS...P-TYPE...AND TIMING. WE WILL
BE SEEING A PIECE OF ENERGY EJECT FROM THE DEVELOPING SW U.S. LOW
AND HEADING TOWARD THE AREA. AT THE SAME TIME...A NRN STREAM SYSTEM
WILL MOVE TOWARD THE AREA. THE BIG UNCERTAINTY COME WITH HOW
MUCH...IF ANY PHASING TAKES PLACE. NOT REALLY A LOT OF RUN-TO-RUN
CONTINUITY WITH THIS SYSTEM. IF IT PHASES...WE COULD SEE A LOT MORE
PCPN WITH MIXED P-TYPES. IF IT REMAINS UNPHASED...WE WILL SEE LESS
PCPN AND SNOW AS THE MAIN P-TYPE.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1159 PM EST WED FEB 25 2015

OCCASIONAL LIGHT SNOW WILL BRING VSBYS OF 2-4 MILES OVERNIGHT AND
THURSDAY MORNING MAINLY SOUTH AND EAST OF GRR. THE LIGHT SNOW WILL
END BETWEEN 14Z AND 18Z THURSDAY FROM NORTHWEST TO SOUTHEAST.
MAINLY MVFR CONDITIONS TONIGHT AND THURSDAY MORNING SOUTH AND EAST
OF GRR ARE EXPECTED TO IMPROVE TO PRIMARILY VFR CONDITIONS AFTER
18Z THURSDAY.

&&

.HYDROLOGY...
ISSUED AT 310 PM EST WED FEB 25 2015

RIVER LEVELS ARE HOLDING STEADY WELL BELOW BANKFULL WITH ONLY MINOR
FLUCTUATIONS AT SEVERAL SITES. RIVER SURFACES ARE MOSTLY TO ENTIRELY
ICE/SNOW COVERED AND FLOW UNDERNEATH THE ICE DOES NOT APPEAR TO BE
IMPEDED BY ICE JAMS AT ANY GAUGE SITE CURRENTLY. THE RISK OF
FLOODING WILL REMAIN RATHER LIMITED UNTIL A WARM UP OR SIGNIFICANT
RAINFALL COMES AROUND.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&

$$

SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...NJJ
AVIATION...MEADE
HYDROLOGY...CAS








000
FXUS63 KGRR 260014
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
714 PM EST WED FEB 25 2015

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 310 PM EST WED FEB 25 2015

A SYSTEM PASSING SOUTH OF MICHIGAN WILL BRING LIGHT SNOW TO THE
AREA FROM LATER THIS EVENING INTO EARLY THURSDAY. A LARGE POLAR
HIGH PRESSURE SYSTEM WILL THEN CONTROL THE WEATHER OVER SOUTHWEST
MICHIGAN THROUGH SATURDAY MORNING. VERY COLD TEMPERATURES ARE
EXPECTED THROUGH SATURDAY MORNING. A SLOW WARMING TREND BEGINS
SATURDAY. BY SUNDAY ENOUGH MOISTURE REACHES MICHIGAN TO BRING SNOW
TO THE AREA AS A WEAK SYSTEM PASSES WELL SOUTH OF MICHIGAN.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 310 PM EST WED FEB 25 2015

I EXPECT LIGHT SNOW TO DEVELOP NEAR INTERSTATE 96 IN A NARROW BAND LATE
THIS EVENING (AROUND 10 PM OR SO). THAT NARROW AREA OF LIGHT SNOW
WILL SLOWLY SPREAD SOUTH AND MERGE WITH AN AREA OF SNOW MOVING
SOUTHEAST FROM WISCONSIN AND ILLINOIS AFTER MIDNIGHT AS I HEADS
TOWARD INTERSTATE 94. SNOWFALL FROM THIS EVENT WILL BE
LIGHT...MOSTLY AND INCH OR LESS. ARCTIC HIGH PRESSURE BUILDS IN
BEHIND THE SYSTEM FOR THURSDAY NIGHT INTO FRIDAY NIGHT SO FOR THE
MOST PART IT WILL JUST BE VERY COLD. WE MAY NEED WIND CHILL
HEADLINES THURSDAY NIGHT AND FRIDAY NIGHT.

THE SYSTEM THIS EVENING IS RATHER CURIOUS IN THAT EVEN THOUGH THE
PRIMARY SYSTEM PASSES WELL SOUTH AND WEST OF MICHIGAN TONIGHT...
BEING UNDER JET EXIT REGION WE STILL GET DEEP LIFT OVER MOST OF
SOUTHWEST LOWER MICHIGAN DURING THE LATE EVENING AND EARLY MORNING
HOURS. DURING THIS TIME THE DGZ IS RATHER DEEP AND NEARLY
SATURATED FROM NEAR THE SURFACE TO 12,000 FT AT MIDNIGHT.
MEANWHILE WE GET A DIFFERENTIAL COOLING BOUNDARY THAT SETS UP JUST
NORTH OF INTERSTATE 96 WHICH RESULTS IN A SURFACE FGEN BAND THAT
MOVES NEARLY DUE SOUTH FROM INTERSTATE 96 AT AROUND MIDNIGHT TO
NEAR INTERSTATE 94 BY 4-5 AM OR SO. WHEN THE JUXTAPOSITION OF THE
DEEP (WEAK )LIFT AND THE SURFACE FGEN COME TOGETHER WE GET A
NARROW BAND OF SNOW SHOWERS NEAR INTERSTATE 96 AS A RESULT (BY
MIDNIGHT). THIS AREA WILL SLOWLY MOVE SOUTH OVER TIME...MERGING
WITH THE SYSTEM PASSING SOUTH OF MICHIGAN BY MORNING. MOST AREAS
WILL SEE LESS THAN AN INCH OF SNOW FROM THIS EVENT.

ALL OF THIS MOVES OUT BY MID MORNING THURSDAY AND THAT ALLOW A
LARGE POLAR HIGH TO BUILD IN WITH MOSTLY NORTHERLY SURFACE WINDS.
THAT WILL KEEP ANY LAKE EFFECT SNOW BANDS OFF SHORE TOMORROW. WITH
NEARLY CLEAR SKIES THURSDAY NIGHT INTO FRIDAY MORNING TEMPERATURES
IN MOST AREAS WILL FALL TO BETWEEN 5 AND 25 BELOW ZERO. LIKELY WE
WILL NEED A WIND CHILL ADVISORY FOR THAT.

.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 310 PM EST WED FEB 25 2015

TWO ITEMS OF INTEREST REMAIN IN THE LONG TERM PORTION OF THE FCST.
THESE ITEMS ARE SYSTEMS THAT WILL POTENTIALLY BRING SOME
ACCUMULATING SNOW TO THE AREA. A PATTERN SHIFT IS STILL EXPECTED
WHERE WILL WILL NOT BE SEEING WAVES OF BRUTALLY COLD AIR AS MUCH AS
THE PAST FEW WEEKS.

THE FIRST POTENTIAL OF ACCUMULATING SNOW WILL COME DURING THE SAT
NIGHT/SUN TIME FRAME AFTER A QUIET SAT. THE EXACT TIMING AND
POSITION IS A LITTLE UNCERTAIN YET. IT DOES APPEAR IT WILL BE
CENTERED AROUND THE LATTER PART OF SAT NIGHT TO SUN MORNING. AS
MENTIONED BEFORE...WE DO NOT SEE MUCH OF AN UPPER WAVE OR SFC
REFLECTION OF A LOW. INSTEAD...WE WILL BECOME UNDER THE INFLUENCE OF
THE LFQ REGION OF A DEVELOPING UPPER JET STREAK DOWNSTREAM OF THE
UPPER LOW DIGGING ACROSS THE SW. IN ADDITION...WE WILL SEE AN INFLUX
OF LOW LEVEL MOISTURE ADVECT IN WITH RETURN FLOW TAPPING THE GULF.

WE WILL SEE A RELATIVELY QUIET PERIOD ON SUN NIGHT THROUGH MON NIGHT
WITH SOMEWHAT MILDER TEMPS HIGH PRESSURE WILL CONTROL THE WEATHER
FROM SUN NIGHT THROUGH MON NIGHT. THERE IS A SMALL CHC OF SOME LAKE
EFFECT NEAR THE LAKESHORE THOSE DAYS. THE OVER LAKE INSTABILITY IS
MARGINAL WITH H850 TEMPS ONLY AROUND -10C OR SO. THE NRN BRANCH OF
THE JET IS NEVER REALLY EXPECTED TO DROP SOUTH OF THE AREA. THIS
WILL KEEP INVERSION HEIGHTS LOW WITH LIMITED MOISTURE DEPTH.

THE SECOND SYSTEM OF INTEREST WILL BE COMING IN FOR THE PERIOD ON
TUE/TUE NIGHT NEXT WEEK. A LOT OF UNCERTAINTY REMAINS WITH THIS
SYSTEM WITH REGARDS TO PCPN AMOUNTS...P-TYPE...AND TIMING. WE WILL
BE SEEING A PIECE OF ENERGY EJECT FROM THE DEVELOPING SW U.S. LOW
AND HEADING TOWARD THE AREA. AT THE SAME TIME...A NRN STREAM SYSTEM
WILL MOVE TOWARD THE AREA. THE BIG UNCERTAINTY COME WITH HOW
MUCH...IF ANY PHASING TAKES PLACE. NOT REALLY A LOT OF RUN-TO-RUN
CONTINUITY WITH THIS SYSTEM. IF IT PHASES...WE COULD SEE A LOT MORE
PCPN WITH MIXED P-TYPES. IF IT REMAINS UNPHASED...WE WILL SEE LESS
PCPN AND SNOW AS THE MAIN P-TYPE.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 714 PM EST WED FEB 25 2015

AN AREA OF LIGHT SNOW WILL OVERSPREAD SRN LWR MI LATER THIS
EVENING AND OVERNIGHT. WE ARE CURRENTLY VFR ACROSS THE ENTIRE AREA
THIS EVENING BUT ONCE THE SNOW ARRIVES AFTER 03Z THE CIGS/VSBYS
SHOULD DROP DOWN INTO AT LEAST MVFR CATEGORY IF NOT IFR FOR MUCH
OF THE OVERNIGHT PERIOD.

CONFIDENCE IN IFR VSBYS IN SNOW DEVELOPING IS HIGHEST AT
AZO/BTL/JXN ALTHOUGH GRR/LAN COULD ALSO SEE A PERIOD OF IFR AS
WELL OVERNIGHT. MKG WILL BE ON THE NORTHERN FRINGES OF THE SNOW SO
IFR MOST UNLIKELY THERE.

THE SNOW WILL END FRIDAY MORNING FROM NORTH TO SOUTH... ENDING AT
GRR BY 14Z BUT LINGERING AT JXN UNTIL ALMOST 18Z. BEHIND THE SNOW
WE SHOULD SEE CIGS GRADUALLY IMPROVING TO VFR IN THE AFTERNOON.

&&

.HYDROLOGY...
ISSUED AT 310 PM EST WED FEB 25 2015

RIVER LEVELS ARE HOLDING STEADY WELL BELOW BANKFULL WITH ONLY MINOR
FLUCTUATIONS AT SEVERAL SITES. RIVER SURFACES ARE MOSTLY TO ENTIRELY
ICE/SNOW COVERED AND FLOW UNDERNEATH THE ICE DOES NOT APPEAR TO BE
IMPEDED BY ICE JAMS AT ANY GAUGE SITE CURRENTLY. THE RISK OF
FLOODING WILL REMAIN RATHER LIMITED UNTIL A WARM UP OR SIGNIFICANT
RAINFALL COMES AROUND.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&

$$

SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...NJJ
AVIATION...MEADE
HYDROLOGY...CAS







000
FXUS63 KGRR 252012
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
312 PM EST WED FEB 25 2015

LATEST UPDATE...
SYNOPSIS/SHORT TERM/LONG TERM/HYDRO

.SYNOPSIS...
ISSUED AT 310 PM EST WED FEB 25 2015

A SYSTEM PASSING SOUTH OF MICHIGAN WILL BRING LIGHT SNOW TO THE
AREA FROM LATER THIS EVENING INTO EARLY THURSDAY. A LARGE POLAR
HIGH PRESSURE SYSTEM WILL THEN CONTROL THE WEATHER OVER SOUTHWEST
MICHIGAN THROUGH SATURDAY MORNING. VERY COLD TEMPERATURES ARE
EXPECTED THROUGH SATURDAY MORNING. A SLOW WARMING TREND BEGINS
SATURDAY. BY SUNDAY ENOUGH MOISTURE REACHES MICHIGAN TO BRING SNOW
TO THE AREA AS A WEAK SYSTEM PASSES WELL SOUTH OF MICHIGAN.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 310 PM EST WED FEB 25 2015

I EXPECT LIGHT SNOW TO DEVELOP NEAR INTERSTATE 96 IN A NARROW BAND LATE
THIS EVENING (AROUND 10 PM OR SO). THAT NARROW AREA OF LIGHT SNOW
WILL SLOWLY SPREAD SOUTH AND MERGE WITH AN AREA OF SNOW MOVING
SOUTHEAST FROM WISCONSIN AND ILLINOIS AFTER MIDNIGHT AS I HEADS
TOWARD INTERSTATE 94. SNOWFALL FROM THIS EVENT WILL BE
LIGHT...MOSTLY AND INCH OR LESS. ARCTIC HIGH PRESSURE BUILDS IN
BEHIND THE SYSTEM FOR THURSDAY NIGHT INTO FRIDAY NIGHT SO FOR THE
MOST PART IT WILL JUST BE VERY COLD. WE MAY NEED WIND CHILL
HEADLINES THURSDAY NIGHT AND FRIDAY NIGHT.

THE SYSTEM THIS EVENING IS RATHER CURIOUS IN THAT EVEN THROUGH THE
PRIMARY SYSTEM PASSES WELL SOUTH AND WEST OF MICHIGAN TONIGHT...
BEING UNDER JET EXIT REGION WE STILL GET DEEP LIFT OVER MOST OF
SOUTHWEST LOWER MICHIGAN DURING THE LATE EVENING AND EARLY MORNING
HOURS. DURING THIS TIME THE DGZ IS RATHER DEEP AND NEARLY
SATURATED FROM NEAR THE SURFACE TO 12,000 FT AT MIDNIGHT.
MEANWHILE WE GET A DIFFERENTIAL COOLING BOUNDARY THAT SETS UP JUST
NORTH OF INTERSTATE 96 WHICH RESULTS IN A SURFACE FGEN BAND THAT
MOVES NEARLY DUE SOUTH FROM INTERSTATE 96 AT AROUND MIDNIGHT TO
NEAR INTERSTATE 94 BY 4-5 AM OR SO. WHEN THE JUXTAPOSITION OF THE
DEEP (WEAK )LIFT AND THE SURFACE FGEN COME TOGETHER WE GET A
NARROW BAND OF SNOW SHOWERS NEAR INTERSTATE 96 AS A RESULT (BY
MIDNIGHT). THIS AREA WILL SLOWLY MOVE SOUTH OVER TIME...MERGING
WITH THE SYSTEM PASSING SOUTH OF MICHIGAN BY MORNING. MOST AREAS
WILL SEE LESS THAN AN INCH OF SNOW FROM THIS EVENT.

ALL OF THIS MOVES OUT BY MID MORNING THURSDAY AND THAT ALLOW A
LARGE POLAR HIGH TO BUILD IN WITH MOSTLY NORTHERLY SURFACE WINDS.
THAT WILL KEEP ANY LAKE EFFECT SNOW BANDS OFF SHORE TOMORROW. WITH
NEARLY CLEAR SKIES THURSDAY NIGHT INTO FRIDAY MORNING TEMPERATURES
IN MOST AREAS WILL FALL TO BETWEEN 5 AND 25 BELOW ZERO. LIKELY WE
WILL NEED A WIND CHILL ADVISORY FOR THAT.


.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 310 PM EST WED FEB 25 2015

TWO ITEMS OF INTEREST REMAIN IN THE LONG TERM PORTION OF THE FCST.
THESE ITEMS ARE SYSTEMS THAT WILL POTENTIALLY BRING SOME
ACCUMULATING SNOW TO THE AREA. A PATTERN SHIFT IS STILL EXPECTED
WHERE WILL WILL NOT BE SEEING WAVES OF BRUTALLY COLD AIR AS MUCH AS
THE PAST FEW WEEKS.

THE FIRST POTENTIAL OF ACCUMULATING SNOW WILL COME DURING THE SAT
NIGHT/SUN TIME FRAME AFTER A QUIET SAT. THE EXACT TIMING AND
POSITION IS A LITTLE UNCERTAIN YET. IT DOES APPEAR IT WILL BE
CENTERED AROUND THE LATTER PART OF SAT NIGHT TO SUN MORNING. AS
MENTIONED BEFORE...WE DO NOT SEE MUCH OF AN UPPER WAVE OR SFC
REFLECTION OF A LOW. INSTEAD...WE WILL BECOME UNDER THE INFLUENCE OF
THE LFQ REGION OF A DEVELOPING UPPER JET STREAK DOWNSTREAM OF THE
UPPER LOW DIGGING ACROSS THE SW. IN ADDITION...WE WILL SEE AN INFLUX
OF LOW LEVEL MOISTURE ADVECT IN WITH RETURN FLOW TAPPING THE GULF.

WE WILL SEE A RELATIVELY QUIET PERIOD ON SUN NIGHT THROUGH MON NIGHT
WITH SOMEWHAT MILDER TEMPS HIGH PRESSURE WILL CONTROL THE WEATHER
FROM SUN NIGHT THROUGH MON NIGHT. THERE IS A SMALL CHC OF SOME LAKE
EFFECT NEAR THE LAKESHORE THOSE DAYS. THE OVER LAKE INSTABILITY IS
MARGINAL WITH H850 TEMPS ONLY AROUND -10C OR SO. THE NRN BRANCH OF
THE JET IS NEVER REALLY EXPECTED TO DROP SOUTH OF THE AREA. THIS
WILL KEEP INVERSION HEIGHTS LOW WITH LIMITED MOISTURE DEPTH.

THE SECOND SYSTEM OF INTEREST WILL BE COMING IN FOR THE PERIOD ON
TUE/TUE NIGHT NEXT WEEK. A LOT OF UNCERTAINTY REMAINS WITH THIS
SYSTEM WITH REGARDS TO PCPN AMOUNTS...P-TYPE...AND TIMING. WE WILL
BE SEEING A PIECE OF ENERGY EJECT FROM THE DEVELOPING SW U.S. LOW
AND HEADING TOWARD THE AREA. AT THE SAME TIME...A NRN STREAM SYSTEM
WILL MOVE TOWARD THE AREA. THE BIG UNCERTAINTY COME WITH HOW
MUCH...IF ANY PHASING TAKES PLACE. NOT REALLY A LOT OF RUN-TO-RUN
CONTINUITY WITH THIS SYSTEM. IF IT PHASES...WE COULD SEE A LOT MORE
PCPN WITH MIXED P-TYPES. IF IT REMAINS UNPHASED...WE WILL SEE LESS
PCPN AND SNOW AS THE MAIN P-TYPE.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1219 PM EST WED FEB 25 2015

OUR MAIN CONCERN WITH THE 18Z FCSTS IS DEALING WITH THE SNOW
COMING IN FROM LATE THIS AFTERNOON THROUGH THU MORNING. MID CLOUDS
ARE NOW STARTING TO STREAM IN OVER THE AREA...WITH SOME
DIURNAL/LAKE EFFECT CLOUD COVER NOW STARTING TO DEVELOP/MOVE
INLAND. WE EXPECT THAT ONLY KMKG WILL SEE THE LOWEST CONDITIONS
THIS AFTERNOON WITH 3500 FT CIGS AND SOME FLURRIES.

LIGHT SNOW WILL THEN BREAK OUT ACROSS THE TERMINALS THIS EVENING
INTO THE EARLY OVERNIGHT HOURS. MODELS ARE INDICATING THAT A LOCAL
BAND MAY SET UP AND POTENTIALLY IMPACT THE KGRR AREA FOR A SHORT
TIME THIS EVENING WITH SOME LOWER VSBYS. MVFR IS LIKELY WITH SOME
LOCAL IFR POSSIBLE.

A LIGHT SNOW WILL THEN LIKELY PERSIST OVERNIGHT AND INTO THU
MORNING. THIS WILL LAST LONGER ACROSS THE SOUTH. THE LOWER
CONDITIONS WILL ALSO BE ACROSS THE SOUTH CLOSER TO THE SYSTEM.
AGAIN...MVFR IS LIKELY WITH SOME IFR POSSIBLE AT TIMES. THIS WILL
GRADUALLY MOVE OUT THU MORNING. CONDITIONS WILL IMPROVE GRADUALLY
THU AFTERNOON.


&&

.HYDROLOGY...
ISSUED AT 310 PM EST WED FEB 25 2015

RIVER LEVELS ARE HOLDING STEADY WELL BELOW BANKFULL WITH ONLY MINOR
FLUCTUATIONS AT SEVERAL SITES. RIVER SURFACES ARE MOSTLY TO ENTIRELY
ICE/SNOW COVERED AND FLOW UNDERNEATH THE ICE DOES NOT APPEAR TO BE
IMPEDED BY ICE JAMS AT ANY GAUGE SITE CURRENTLY. THE RISK OF
FLOODING WILL REMAIN RATHER LIMITED UNTIL A WARM UP OR SIGNIFICANT
RAINFALL COMES AROUND.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&

$$

SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...NJJ
AVIATION...NJJ
HYDROLOGY...CAS








000
FXUS63 KGRR 251720
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1220 PM EST WED FEB 25 2015

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 330 AM EST WED FEB 25 2015

AN ARCTIC AIRMASS WILL REMAIN FIRMLY ENTRENCHED IN THE GREAT LAKES
REGION THROUGH FRIDAY. A WEAK SYSTEM WILL BRING A FEW LIGHT SNOW
SHOWERS TO FAR SOUTHERN LOWER MICHIGAN TONIGHT INTO THURSDAY
MORNING. HIGH PRESSURE WILL BUILD IN TO PRODUCE FAIR BUT COLD
WEATHER THURSDAY THROUGH SATURDAY. TEMPERATURES WILL FINALLY
UNDERGO A GRADUAL MODERATING TREND LATE THIS WEEKEND INTO EARLY
NEXT WEEK.

&&

.UPDATE...
ISSUED AT 1110 AM EST WED FEB 25 2015

THIS IS JUST A QUICK HEADS UP ON MY THINKING FOR TONIGHT. I AM
THINKING IT WILL SNOW TONIGHT (HIGH POP) NEAR AND SOUTH OF I-96.
THIS WILL NOT BE A HEAVY SNOW... MOSTLY AN INCH OR LESS BUT IT
WILL SNOW NONE THE LESS.

AFTER LOOKING AT THE NAM12...RAP13 AND HRRR IT SEEMS TO ME WHAT
WE WILL SEE IS A NARROW BAND OF SNOW DEVELOPING NEAR OR JUST NORTH
OF I-96 AROUND 9 TO 10 PM TONIGHT THAT WILL MOVE SLOWLY SOUTHWARD
(THIS IS SHOWN BY ALL THREE OF THESE MODELS) TO I-94 BY 5 AM. THIS
NARROW BAND IS THE RESULT OF SURFACE FGEN DUE THE RADIATIONAL COOLED
AIR OVER NORTHERN LOWER MICHIGAN COMPARED TO THE CLOUD COVERED AIR
(WHICH WILL NOT COOL) CREATING A THERMAL GRADIENT. THE BEST LIFT
IS JUST ABOVE THE IS NEAR 900 MB WHICH IS IN THE DGZ SO THIS WILL
MAXIMIZE THE SNOWFALL RATES. THIS IS GOING ON UNDER THE ENTRANCE
REGION OF THE UPPER JET SO WE GET DEEP MOISTURE AND DEEP LIFT
(WEAK BUT ALSO IN THE DGZ). AROUND MIDNIGHT THE DGZ OVER GRR IS
FROM 1000 FT TO 12000 FT....MORE THAN DEEP ENOUGH TO HELP THE SNOW
CAUSE. BOTTOM LINE IS I WILL INCREASE THE POP TO OVER 70% OVER THE
SOUTHERN 1/2 OF THE CWA THIS EVENING FOR THIS EVENT.

&&

.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 330 AM EST WED FEB 25 2015

FAIRLY TRANQUIL AND COLD WEATHER IS ANTICIPATED THROUGH THE SHORT
TERM FCST PERIOD. A FEW LIGHT SNOW SHOWERS AND FLURRIES WILL
LINGER INTO THIS MORNING BUT WITH VERY LITTLE TO NO ADDITIONAL
SNOW ACCUMULATION. MOST OF THE DAY WILL BE DRY BUT COLD WITH A MIX
OF SUN AND CLOUDS. MAX TEMPS WILL ONLY REACH 10 TO 15 DEGREES.

A WEAK SYSTEM MOVING ESE FROM THE NORTHERN PLAINS STATES EARLY
THIS MORNING WILL BRING A FEW LIGHT SNOW SHOWERS AND FLURRIES TO
OUR SOUTHERN FCST AREA NEAR TO MAINLY SOUTH OF I-96 TONIGHT INTO
THURSDAY MORNING... WITH VERY LIGHT SNOW ACCUMULATIONS OF UNDER AN
INCH.

BEYOND THAT HIGH PRESSURE WILL BUILD IN TO PRODUCE FAIR BUT COLD
WX THURSDAY AFTERNOON THROUGH FRIDAY. MAX TEMPS THURSDAY WILL
STRUGGLE TO REACH THE UPPER SINGLE DIGITS TO LOWER TEENS AND MINS
THURSDAY NIGHT WILL FALL TO BELOW ZERO ACROSS OUR AREA AS SKIES
CLEAR AND WITH LIGHT WINDS AND EXPANSIVE SNOW COVER IN PLACE. MAX
TEMPS FRIDAY WILL STRUGGLE TO REACH THE LOWER TO MIDDLE TEENS IN
SPITE OF LOTS OF SUN AFTER A VERY COLD START TO THE DAY.

.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 330 AM EST WED FEB 25 2015

UPPER AIR PATTERN SHIFT IS STILL FORECAST TO OCCUR BY THE 00Z MODEL
RUNS DURING THE LONG TERM. THE PERSISTENT UPPER TROUGH IS IN THE
PROCESS OF LIFTING OUT FRIDAY NIGHT. BY EARLY NEXT WEEK A SOUTHWEST
FLOW DEVELOPS ACROSS THE LOWER 48...FROM THE SOUTHWEST U.S. TO THE
GREAT LAKES.

THERE ARE TWO MAIN ITEMS TO KEEP AN EYE ON THROUGH THE PERIOD. THE
FIRST IS THE SNOW EVENT FOR SUNDAY AND SUNDAY NIGHT. IT REMAINS AN
EVENT WITH NO SURFACE LOW TO KEY ON. SNOW IS PRODUCED VIA A WEAK
FRONTAL BOUNDARY SLIPPING THROUGH THE AREA COUPLED WITH AN UPPER
LEVEL SHORT WAVE AND ISENTROPIC LIFT. IT APPEARS TO BE A 2-5 INCH
SNOW POTENTIALLY FOR THE SOUTHERN HALF OF THE FORECAST AREA. WE
STILL HAVE PLENTY OF TIME TO NAIL DOWN THE DETAILS WITH THIS SYSTEM.

THE SECOND SIGNIFICANT FEATURE TO KEEP AN EYE ON IS A SYSTEM NEXT
WEEK IN THE TUESDAY OR WEDNESDAY TIME FRAME. LOW CONFIDENCE IN THIS
TIME FRAME AS THE GFS IS QUICKER...BRINGING A DEEP LOW THROUGH THE
AREA ON TUESDAY. THE ECMWF AND CANADIAN ARE SLOWER AND BRING THE
SYSTEM THROUGH ON WEDNESDAY. AT THIS POINT...SIDING WITH THE ECMWF
AND CANADIAN AND THE SLOWER SYSTEM. THE SYSTEM TAPS GULF MOISTURE IN
DEEP SOUTHERLY FLOW. PRECIPITATION TYPE ISSUES COME INTO PLAY
TUESDAY NIGHT IN THE ECMWF/CANADIAN SOLUTIONS WITH +4 TO +6 850MB
AIR SURGING IN FROM THE SOUTH. THESE VALUES WOULD YIELD RAIN AS THE
PRECIP TYPE ALONG I94. MODELS ARE HAVING ISSUES WITH THIS SYSTEM AS
ITS DRIVEN BY A WAVE EJECTING OUT OF THE SOUTHWEST U.S. TROUGH. WE
WILL BE MONITORING TRENDS WITH THIS SYSTEM IN THE COMING DAYS.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1219 PM EST WED FEB 25 2015

OUR MAIN CONCERN WITH THE 18Z FCSTS IS DEALING WITH THE SNOW
COMING IN FROM LATE THIS AFTERNOON THROUGH THU MORNING. MID CLOUDS
ARE NOW STARTING TO STREAM IN OVER THE AREA...WITH SOME
DIURNAL/LAKE EFFECT CLOUD COVER NOW STARTING TO DEVELOP/MOVE
INLAND. WE EXPECT THAT ONLY KMKG WILL SEE THE LOWEST CONDITIONS
THIS AFTERNOON WITH 3500 FT CIGS AND SOME FLURRIES.

LIGHT SNOW WILL THEN BREAK OUT ACROSS THE TERMINALS THIS EVENING
INTO THE EARLY OVERNIGHT HOURS. MODELS ARE INDICATING THAT A LOCAL
BAND MAY SET UP AND POTENTIALLY IMPACT THE KGRR AREA FOR A SHORT
TIME THIS EVENING WITH SOME LOWER VSBYS. MVFR IS LIKELY WITH SOME
LOCAL IFR POSSIBLE.

A LIGHT SNOW WILL THEN LIKELY PERSIST OVERNIGHT AND INTO THU
MORNING. THIS WILL LAST LONGER ACROSS THE SOUTH. THE LOWER
CONDITIONS WILL ALSO BE ACROSS THE SOUTH CLOSER TO THE SYSTEM.
AGAIN...MVFR IS LIKELY WITH SOME IFR POSSIBLE AT TIMES. THIS WILL
GRADUALLY MOVE OUT THU MORNING. CONDITIONS WILL IMPROVE GRADUALLY
THU AFTERNOON.

&&

.HYDROLOGY...
ISSUED AT 224 PM EST TUE FEB 24 2015

CURRENTLY NO SUSPECTED ICE JAMS AND RIVER LEVELS ARE HOLDING RATHER
STEADY. FORECAST CALLS FOR BELOW FREEZING TEMPERATURES INTO NEXT
WEEK WITH OCCASIONAL SNOW OPPORTUNITIES. THE RISK OF FLOODING IS
FAIRLY LIMITED UNTIL A NOTABLE WARM-UP OR RAIN EVENT.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&

$$

UPDATE...WDM
SYNOPSIS...LAURENS
SHORT TERM...LAURENS
LONG TERM...DUKE
AVIATION...NJJ
HYDROLOGY...CAS







000
FXUS63 KGRR 251720
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1220 PM EST WED FEB 25 2015

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 330 AM EST WED FEB 25 2015

AN ARCTIC AIRMASS WILL REMAIN FIRMLY ENTRENCHED IN THE GREAT LAKES
REGION THROUGH FRIDAY. A WEAK SYSTEM WILL BRING A FEW LIGHT SNOW
SHOWERS TO FAR SOUTHERN LOWER MICHIGAN TONIGHT INTO THURSDAY
MORNING. HIGH PRESSURE WILL BUILD IN TO PRODUCE FAIR BUT COLD
WEATHER THURSDAY THROUGH SATURDAY. TEMPERATURES WILL FINALLY
UNDERGO A GRADUAL MODERATING TREND LATE THIS WEEKEND INTO EARLY
NEXT WEEK.

&&

.UPDATE...
ISSUED AT 1110 AM EST WED FEB 25 2015

THIS IS JUST A QUICK HEADS UP ON MY THINKING FOR TONIGHT. I AM
THINKING IT WILL SNOW TONIGHT (HIGH POP) NEAR AND SOUTH OF I-96.
THIS WILL NOT BE A HEAVY SNOW... MOSTLY AN INCH OR LESS BUT IT
WILL SNOW NONE THE LESS.

AFTER LOOKING AT THE NAM12...RAP13 AND HRRR IT SEEMS TO ME WHAT
WE WILL SEE IS A NARROW BAND OF SNOW DEVELOPING NEAR OR JUST NORTH
OF I-96 AROUND 9 TO 10 PM TONIGHT THAT WILL MOVE SLOWLY SOUTHWARD
(THIS IS SHOWN BY ALL THREE OF THESE MODELS) TO I-94 BY 5 AM. THIS
NARROW BAND IS THE RESULT OF SURFACE FGEN DUE THE RADIATIONAL COOLED
AIR OVER NORTHERN LOWER MICHIGAN COMPARED TO THE CLOUD COVERED AIR
(WHICH WILL NOT COOL) CREATING A THERMAL GRADIENT. THE BEST LIFT
IS JUST ABOVE THE IS NEAR 900 MB WHICH IS IN THE DGZ SO THIS WILL
MAXIMIZE THE SNOWFALL RATES. THIS IS GOING ON UNDER THE ENTRANCE
REGION OF THE UPPER JET SO WE GET DEEP MOISTURE AND DEEP LIFT
(WEAK BUT ALSO IN THE DGZ). AROUND MIDNIGHT THE DGZ OVER GRR IS
FROM 1000 FT TO 12000 FT....MORE THAN DEEP ENOUGH TO HELP THE SNOW
CAUSE. BOTTOM LINE IS I WILL INCREASE THE POP TO OVER 70% OVER THE
SOUTHERN 1/2 OF THE CWA THIS EVENING FOR THIS EVENT.

&&

.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 330 AM EST WED FEB 25 2015

FAIRLY TRANQUIL AND COLD WEATHER IS ANTICIPATED THROUGH THE SHORT
TERM FCST PERIOD. A FEW LIGHT SNOW SHOWERS AND FLURRIES WILL
LINGER INTO THIS MORNING BUT WITH VERY LITTLE TO NO ADDITIONAL
SNOW ACCUMULATION. MOST OF THE DAY WILL BE DRY BUT COLD WITH A MIX
OF SUN AND CLOUDS. MAX TEMPS WILL ONLY REACH 10 TO 15 DEGREES.

A WEAK SYSTEM MOVING ESE FROM THE NORTHERN PLAINS STATES EARLY
THIS MORNING WILL BRING A FEW LIGHT SNOW SHOWERS AND FLURRIES TO
OUR SOUTHERN FCST AREA NEAR TO MAINLY SOUTH OF I-96 TONIGHT INTO
THURSDAY MORNING... WITH VERY LIGHT SNOW ACCUMULATIONS OF UNDER AN
INCH.

BEYOND THAT HIGH PRESSURE WILL BUILD IN TO PRODUCE FAIR BUT COLD
WX THURSDAY AFTERNOON THROUGH FRIDAY. MAX TEMPS THURSDAY WILL
STRUGGLE TO REACH THE UPPER SINGLE DIGITS TO LOWER TEENS AND MINS
THURSDAY NIGHT WILL FALL TO BELOW ZERO ACROSS OUR AREA AS SKIES
CLEAR AND WITH LIGHT WINDS AND EXPANSIVE SNOW COVER IN PLACE. MAX
TEMPS FRIDAY WILL STRUGGLE TO REACH THE LOWER TO MIDDLE TEENS IN
SPITE OF LOTS OF SUN AFTER A VERY COLD START TO THE DAY.

.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 330 AM EST WED FEB 25 2015

UPPER AIR PATTERN SHIFT IS STILL FORECAST TO OCCUR BY THE 00Z MODEL
RUNS DURING THE LONG TERM. THE PERSISTENT UPPER TROUGH IS IN THE
PROCESS OF LIFTING OUT FRIDAY NIGHT. BY EARLY NEXT WEEK A SOUTHWEST
FLOW DEVELOPS ACROSS THE LOWER 48...FROM THE SOUTHWEST U.S. TO THE
GREAT LAKES.

THERE ARE TWO MAIN ITEMS TO KEEP AN EYE ON THROUGH THE PERIOD. THE
FIRST IS THE SNOW EVENT FOR SUNDAY AND SUNDAY NIGHT. IT REMAINS AN
EVENT WITH NO SURFACE LOW TO KEY ON. SNOW IS PRODUCED VIA A WEAK
FRONTAL BOUNDARY SLIPPING THROUGH THE AREA COUPLED WITH AN UPPER
LEVEL SHORT WAVE AND ISENTROPIC LIFT. IT APPEARS TO BE A 2-5 INCH
SNOW POTENTIALLY FOR THE SOUTHERN HALF OF THE FORECAST AREA. WE
STILL HAVE PLENTY OF TIME TO NAIL DOWN THE DETAILS WITH THIS SYSTEM.

THE SECOND SIGNIFICANT FEATURE TO KEEP AN EYE ON IS A SYSTEM NEXT
WEEK IN THE TUESDAY OR WEDNESDAY TIME FRAME. LOW CONFIDENCE IN THIS
TIME FRAME AS THE GFS IS QUICKER...BRINGING A DEEP LOW THROUGH THE
AREA ON TUESDAY. THE ECMWF AND CANADIAN ARE SLOWER AND BRING THE
SYSTEM THROUGH ON WEDNESDAY. AT THIS POINT...SIDING WITH THE ECMWF
AND CANADIAN AND THE SLOWER SYSTEM. THE SYSTEM TAPS GULF MOISTURE IN
DEEP SOUTHERLY FLOW. PRECIPITATION TYPE ISSUES COME INTO PLAY
TUESDAY NIGHT IN THE ECMWF/CANADIAN SOLUTIONS WITH +4 TO +6 850MB
AIR SURGING IN FROM THE SOUTH. THESE VALUES WOULD YIELD RAIN AS THE
PRECIP TYPE ALONG I94. MODELS ARE HAVING ISSUES WITH THIS SYSTEM AS
ITS DRIVEN BY A WAVE EJECTING OUT OF THE SOUTHWEST U.S. TROUGH. WE
WILL BE MONITORING TRENDS WITH THIS SYSTEM IN THE COMING DAYS.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1219 PM EST WED FEB 25 2015

OUR MAIN CONCERN WITH THE 18Z FCSTS IS DEALING WITH THE SNOW
COMING IN FROM LATE THIS AFTERNOON THROUGH THU MORNING. MID CLOUDS
ARE NOW STARTING TO STREAM IN OVER THE AREA...WITH SOME
DIURNAL/LAKE EFFECT CLOUD COVER NOW STARTING TO DEVELOP/MOVE
INLAND. WE EXPECT THAT ONLY KMKG WILL SEE THE LOWEST CONDITIONS
THIS AFTERNOON WITH 3500 FT CIGS AND SOME FLURRIES.

LIGHT SNOW WILL THEN BREAK OUT ACROSS THE TERMINALS THIS EVENING
INTO THE EARLY OVERNIGHT HOURS. MODELS ARE INDICATING THAT A LOCAL
BAND MAY SET UP AND POTENTIALLY IMPACT THE KGRR AREA FOR A SHORT
TIME THIS EVENING WITH SOME LOWER VSBYS. MVFR IS LIKELY WITH SOME
LOCAL IFR POSSIBLE.

A LIGHT SNOW WILL THEN LIKELY PERSIST OVERNIGHT AND INTO THU
MORNING. THIS WILL LAST LONGER ACROSS THE SOUTH. THE LOWER
CONDITIONS WILL ALSO BE ACROSS THE SOUTH CLOSER TO THE SYSTEM.
AGAIN...MVFR IS LIKELY WITH SOME IFR POSSIBLE AT TIMES. THIS WILL
GRADUALLY MOVE OUT THU MORNING. CONDITIONS WILL IMPROVE GRADUALLY
THU AFTERNOON.

&&

.HYDROLOGY...
ISSUED AT 224 PM EST TUE FEB 24 2015

CURRENTLY NO SUSPECTED ICE JAMS AND RIVER LEVELS ARE HOLDING RATHER
STEADY. FORECAST CALLS FOR BELOW FREEZING TEMPERATURES INTO NEXT
WEEK WITH OCCASIONAL SNOW OPPORTUNITIES. THE RISK OF FLOODING IS
FAIRLY LIMITED UNTIL A NOTABLE WARM-UP OR RAIN EVENT.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&

$$

UPDATE...WDM
SYNOPSIS...LAURENS
SHORT TERM...LAURENS
LONG TERM...DUKE
AVIATION...NJJ
HYDROLOGY...CAS








000
FXUS63 KGRR 251720
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1220 PM EST WED FEB 25 2015

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 330 AM EST WED FEB 25 2015

AN ARCTIC AIRMASS WILL REMAIN FIRMLY ENTRENCHED IN THE GREAT LAKES
REGION THROUGH FRIDAY. A WEAK SYSTEM WILL BRING A FEW LIGHT SNOW
SHOWERS TO FAR SOUTHERN LOWER MICHIGAN TONIGHT INTO THURSDAY
MORNING. HIGH PRESSURE WILL BUILD IN TO PRODUCE FAIR BUT COLD
WEATHER THURSDAY THROUGH SATURDAY. TEMPERATURES WILL FINALLY
UNDERGO A GRADUAL MODERATING TREND LATE THIS WEEKEND INTO EARLY
NEXT WEEK.

&&

.UPDATE...
ISSUED AT 1110 AM EST WED FEB 25 2015

THIS IS JUST A QUICK HEADS UP ON MY THINKING FOR TONIGHT. I AM
THINKING IT WILL SNOW TONIGHT (HIGH POP) NEAR AND SOUTH OF I-96.
THIS WILL NOT BE A HEAVY SNOW... MOSTLY AN INCH OR LESS BUT IT
WILL SNOW NONE THE LESS.

AFTER LOOKING AT THE NAM12...RAP13 AND HRRR IT SEEMS TO ME WHAT
WE WILL SEE IS A NARROW BAND OF SNOW DEVELOPING NEAR OR JUST NORTH
OF I-96 AROUND 9 TO 10 PM TONIGHT THAT WILL MOVE SLOWLY SOUTHWARD
(THIS IS SHOWN BY ALL THREE OF THESE MODELS) TO I-94 BY 5 AM. THIS
NARROW BAND IS THE RESULT OF SURFACE FGEN DUE THE RADIATIONAL COOLED
AIR OVER NORTHERN LOWER MICHIGAN COMPARED TO THE CLOUD COVERED AIR
(WHICH WILL NOT COOL) CREATING A THERMAL GRADIENT. THE BEST LIFT
IS JUST ABOVE THE IS NEAR 900 MB WHICH IS IN THE DGZ SO THIS WILL
MAXIMIZE THE SNOWFALL RATES. THIS IS GOING ON UNDER THE ENTRANCE
REGION OF THE UPPER JET SO WE GET DEEP MOISTURE AND DEEP LIFT
(WEAK BUT ALSO IN THE DGZ). AROUND MIDNIGHT THE DGZ OVER GRR IS
FROM 1000 FT TO 12000 FT....MORE THAN DEEP ENOUGH TO HELP THE SNOW
CAUSE. BOTTOM LINE IS I WILL INCREASE THE POP TO OVER 70% OVER THE
SOUTHERN 1/2 OF THE CWA THIS EVENING FOR THIS EVENT.

&&

.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 330 AM EST WED FEB 25 2015

FAIRLY TRANQUIL AND COLD WEATHER IS ANTICIPATED THROUGH THE SHORT
TERM FCST PERIOD. A FEW LIGHT SNOW SHOWERS AND FLURRIES WILL
LINGER INTO THIS MORNING BUT WITH VERY LITTLE TO NO ADDITIONAL
SNOW ACCUMULATION. MOST OF THE DAY WILL BE DRY BUT COLD WITH A MIX
OF SUN AND CLOUDS. MAX TEMPS WILL ONLY REACH 10 TO 15 DEGREES.

A WEAK SYSTEM MOVING ESE FROM THE NORTHERN PLAINS STATES EARLY
THIS MORNING WILL BRING A FEW LIGHT SNOW SHOWERS AND FLURRIES TO
OUR SOUTHERN FCST AREA NEAR TO MAINLY SOUTH OF I-96 TONIGHT INTO
THURSDAY MORNING... WITH VERY LIGHT SNOW ACCUMULATIONS OF UNDER AN
INCH.

BEYOND THAT HIGH PRESSURE WILL BUILD IN TO PRODUCE FAIR BUT COLD
WX THURSDAY AFTERNOON THROUGH FRIDAY. MAX TEMPS THURSDAY WILL
STRUGGLE TO REACH THE UPPER SINGLE DIGITS TO LOWER TEENS AND MINS
THURSDAY NIGHT WILL FALL TO BELOW ZERO ACROSS OUR AREA AS SKIES
CLEAR AND WITH LIGHT WINDS AND EXPANSIVE SNOW COVER IN PLACE. MAX
TEMPS FRIDAY WILL STRUGGLE TO REACH THE LOWER TO MIDDLE TEENS IN
SPITE OF LOTS OF SUN AFTER A VERY COLD START TO THE DAY.

.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 330 AM EST WED FEB 25 2015

UPPER AIR PATTERN SHIFT IS STILL FORECAST TO OCCUR BY THE 00Z MODEL
RUNS DURING THE LONG TERM. THE PERSISTENT UPPER TROUGH IS IN THE
PROCESS OF LIFTING OUT FRIDAY NIGHT. BY EARLY NEXT WEEK A SOUTHWEST
FLOW DEVELOPS ACROSS THE LOWER 48...FROM THE SOUTHWEST U.S. TO THE
GREAT LAKES.

THERE ARE TWO MAIN ITEMS TO KEEP AN EYE ON THROUGH THE PERIOD. THE
FIRST IS THE SNOW EVENT FOR SUNDAY AND SUNDAY NIGHT. IT REMAINS AN
EVENT WITH NO SURFACE LOW TO KEY ON. SNOW IS PRODUCED VIA A WEAK
FRONTAL BOUNDARY SLIPPING THROUGH THE AREA COUPLED WITH AN UPPER
LEVEL SHORT WAVE AND ISENTROPIC LIFT. IT APPEARS TO BE A 2-5 INCH
SNOW POTENTIALLY FOR THE SOUTHERN HALF OF THE FORECAST AREA. WE
STILL HAVE PLENTY OF TIME TO NAIL DOWN THE DETAILS WITH THIS SYSTEM.

THE SECOND SIGNIFICANT FEATURE TO KEEP AN EYE ON IS A SYSTEM NEXT
WEEK IN THE TUESDAY OR WEDNESDAY TIME FRAME. LOW CONFIDENCE IN THIS
TIME FRAME AS THE GFS IS QUICKER...BRINGING A DEEP LOW THROUGH THE
AREA ON TUESDAY. THE ECMWF AND CANADIAN ARE SLOWER AND BRING THE
SYSTEM THROUGH ON WEDNESDAY. AT THIS POINT...SIDING WITH THE ECMWF
AND CANADIAN AND THE SLOWER SYSTEM. THE SYSTEM TAPS GULF MOISTURE IN
DEEP SOUTHERLY FLOW. PRECIPITATION TYPE ISSUES COME INTO PLAY
TUESDAY NIGHT IN THE ECMWF/CANADIAN SOLUTIONS WITH +4 TO +6 850MB
AIR SURGING IN FROM THE SOUTH. THESE VALUES WOULD YIELD RAIN AS THE
PRECIP TYPE ALONG I94. MODELS ARE HAVING ISSUES WITH THIS SYSTEM AS
ITS DRIVEN BY A WAVE EJECTING OUT OF THE SOUTHWEST U.S. TROUGH. WE
WILL BE MONITORING TRENDS WITH THIS SYSTEM IN THE COMING DAYS.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1219 PM EST WED FEB 25 2015

OUR MAIN CONCERN WITH THE 18Z FCSTS IS DEALING WITH THE SNOW
COMING IN FROM LATE THIS AFTERNOON THROUGH THU MORNING. MID CLOUDS
ARE NOW STARTING TO STREAM IN OVER THE AREA...WITH SOME
DIURNAL/LAKE EFFECT CLOUD COVER NOW STARTING TO DEVELOP/MOVE
INLAND. WE EXPECT THAT ONLY KMKG WILL SEE THE LOWEST CONDITIONS
THIS AFTERNOON WITH 3500 FT CIGS AND SOME FLURRIES.

LIGHT SNOW WILL THEN BREAK OUT ACROSS THE TERMINALS THIS EVENING
INTO THE EARLY OVERNIGHT HOURS. MODELS ARE INDICATING THAT A LOCAL
BAND MAY SET UP AND POTENTIALLY IMPACT THE KGRR AREA FOR A SHORT
TIME THIS EVENING WITH SOME LOWER VSBYS. MVFR IS LIKELY WITH SOME
LOCAL IFR POSSIBLE.

A LIGHT SNOW WILL THEN LIKELY PERSIST OVERNIGHT AND INTO THU
MORNING. THIS WILL LAST LONGER ACROSS THE SOUTH. THE LOWER
CONDITIONS WILL ALSO BE ACROSS THE SOUTH CLOSER TO THE SYSTEM.
AGAIN...MVFR IS LIKELY WITH SOME IFR POSSIBLE AT TIMES. THIS WILL
GRADUALLY MOVE OUT THU MORNING. CONDITIONS WILL IMPROVE GRADUALLY
THU AFTERNOON.

&&

.HYDROLOGY...
ISSUED AT 224 PM EST TUE FEB 24 2015

CURRENTLY NO SUSPECTED ICE JAMS AND RIVER LEVELS ARE HOLDING RATHER
STEADY. FORECAST CALLS FOR BELOW FREEZING TEMPERATURES INTO NEXT
WEEK WITH OCCASIONAL SNOW OPPORTUNITIES. THE RISK OF FLOODING IS
FAIRLY LIMITED UNTIL A NOTABLE WARM-UP OR RAIN EVENT.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&

$$

UPDATE...WDM
SYNOPSIS...LAURENS
SHORT TERM...LAURENS
LONG TERM...DUKE
AVIATION...NJJ
HYDROLOGY...CAS








000
FXUS63 KGRR 251610
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1110 AM EST WED FEB 25 2015

LATEST UPDATE...
UPDATE

.SYNOPSIS...
ISSUED AT 330 AM EST WED FEB 25 2015

AN ARCTIC AIRMASS WILL REMAIN FIRMLY ENTRENCHED IN THE GREAT LAKES
REGION THROUGH FRIDAY. A WEAK SYSTEM WILL BRING A FEW LIGHT SNOW
SHOWERS TO FAR SOUTHERN LOWER MICHIGAN TONIGHT INTO THURSDAY
MORNING. HIGH PRESSURE WILL BUILD IN TO PRODUCE FAIR BUT COLD
WEATHER THURSDAY THROUGH SATURDAY. TEMPERATURES WILL FINALLY
UNDERGO A GRADUAL MODERATING TREND LATE THIS WEEKEND INTO EARLY
NEXT WEEK.

&&

.UPDATE...
ISSUED AT 1110 AM EST WED FEB 25 2015

THIS IS JUST A QUICK HEADS UP ON MY THINKING FOR TONIGHT. I AM
THINKING IT WILL SNOW TONIGHT (HIGH POP) NEAR AND SOUTH OF I-96.
THIS WILL NOT BE A HEAVY SNOW... MOSTLY AN INCH OR LESS BUT IT
WILL SNOW NONE THE LESS.

AFTER LOOKING AT THE NAM12...RAP13 AND HRRR IT SEEMS TO ME WHAT
WE WILL SEE IS A NARROW BAND OF SNOW DEVELOPING NEAR OR JUST NORTH
OF I-96 AROUND 9 TO 10 PM TONIGHT THAT WILL MOVE SLOWLY SOUTHWARD
(THIS IS SHOWN BY ALL THREE OF THESE MODELS) TO I-94 BY 5 AM. THIS
NARROW BAND IS THE RESULT OF SURFACE FGEN DUE THE RADIATIONAL COOLED
AIR OVER NORTHERN LOWER MICHIGAN COMPARED TO THE CLOUD COVERED AIR
(WHICH WILL NOT COOL) CREATING A THERMAL GRADIENT. THE BEST LIFT
IS JUST ABOVE THE IS NEAR 900 MB WHICH IS IN THE DGZ SO THIS WILL
MAXIMIZE THE SNOWFALL RATES. THIS IS GOING ON UNDER THE ENTRANCE
REGION OF THE UPPER JET SO WE GET DEEP MOISTURE AND DEEP LIFT
(WEAK BUT ALSO IN THE DGZ). AROUND MIDNIGHT THE DGZ OVER GRR IS
FROM 1000 FT TO 12000 FT....MORE THAN DEEP ENOUGH TO HELP THE SNOW
CAUSE. BOTTOM LINE IS I WILL INCREASE THE POP TO OVER 70% OVER THE
SOUTHERN 1/2 OF THE CWA THIS EVENING FOR THIS EVENT.

&&

.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 330 AM EST WED FEB 25 2015

FAIRLY TRANQUIL AND COLD WEATHER IS ANTICIPATED THROUGH THE SHORT
TERM FCST PERIOD. A FEW LIGHT SNOW SHOWERS AND FLURRIES WILL
LINGER INTO THIS MORNING BUT WITH VERY LITTLE TO NO ADDITIONAL
SNOW ACCUMULATION. MOST OF THE DAY WILL BE DRY BUT COLD WITH A MIX
OF SUN AND CLOUDS. MAX TEMPS WILL ONLY REACH 10 TO 15 DEGREES.

A WEAK SYSTEM MOVING ESE FROM THE NORTHERN PLAINS STATES EARLY
THIS MORNING WILL BRING A FEW LIGHT SNOW SHOWERS AND FLURRIES TO
OUR SOUTHERN FCST AREA NEAR TO MAINLY SOUTH OF I-96 TONIGHT INTO
THURSDAY MORNING... WITH VERY LIGHT SNOW ACCUMULATIONS OF UNDER AN
INCH.

BEYOND THAT HIGH PRESSURE WILL BUILD IN TO PRODUCE FAIR BUT COLD
WX THURSDAY AFTERNOON THROUGH FRIDAY. MAX TEMPS THURSDAY WILL
STRUGGLE TO REACH THE UPPER SINGLE DIGITS TO LOWER TEENS AND MINS
THURSDAY NIGHT WILL FALL TO BELOW ZERO ACROSS OUR AREA AS SKIES
CLEAR AND WITH LIGHT WINDS AND EXPANSIVE SNOW COVER IN PLACE. MAX
TEMPS FRIDAY WILL STRUGGLE TO REACH THE LOWER TO MIDDLE TEENS IN
SPITE OF LOTS OF SUN AFTER A VERY COLD START TO THE DAY.

.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 330 AM EST WED FEB 25 2015

UPPER AIR PATTERN SHIFT IS STILL FORECAST TO OCCUR BY THE 00Z MODEL
RUNS DURING THE LONG TERM. THE PERSISTENT UPPER TROUGH IS IN THE
PROCESS OF LIFTING OUT FRIDAY NIGHT. BY EARLY NEXT WEEK A SOUTHWEST
FLOW DEVELOPS ACROSS THE LOWER 48...FROM THE SOUTHWEST U.S. TO THE
GREAT LAKES.

THERE ARE TWO MAIN ITEMS TO KEEP AN EYE ON THROUGH THE PERIOD. THE
FIRST IS THE SNOW EVENT FOR SUNDAY AND SUNDAY NIGHT. IT REMAINS AN
EVENT WITH NO SURFACE LOW TO KEY ON. SNOW IS PRODUCED VIA A WEAK
FRONTAL BOUNDARY SLIPPING THROUGH THE AREA COUPLED WITH AN UPPER
LEVEL SHORT WAVE AND ISENTROPIC LIFT. IT APPEARS TO BE A 2-5 INCH
SNOW POTENTIALLY FOR THE SOUTHERN HALF OF THE FORECAST AREA. WE
STILL HAVE PLENTY OF TIME TO NAIL DOWN THE DETAILS WITH THIS SYSTEM.

THE SECOND SIGNIFICANT FEATURE TO KEEP AN EYE ON IS A SYSTEM NEXT
WEEK IN THE TUESDAY OR WEDNESDAY TIME FRAME. LOW CONFIDENCE IN THIS
TIME FRAME AS THE GFS IS QUICKER...BRINGING A DEEP LOW THROUGH THE
AREA ON TUESDAY. THE ECMWF AND CANADIAN ARE SLOWER AND BRING THE
SYSTEM THROUGH ON WEDNESDAY. AT THIS POINT...SIDING WITH THE ECWMF
AND CANADIAN AND THE SLOWER SYSTEM. THE SYSTEM TAPS GULF MOISTURE IN
DEEP SOUTHERLY FLOW. PRECIPITATION TYPE ISSUES COME INTO PLAY
TUESDAY NIGHT IN THE ECMWF/CANADIAN SOLUTIONS WITH +4 TO +6 850MB
AIR SURGING IN FROM THE SOUTH. THESE VALUES WOULD YIELD RAIN AS THE
PRECIP TYPE ALONG I94. MODELS ARE HAVING ISSUES WITH THIS SYSTEM AS
ITS DRIVEN BY A WAVE EJECTING OUT OF THE SOUTHWEST U.S. TROUGH. WE
WILL BE MONITORING TRENDS WITH THIS SYSTEM IN THE COMING DAYS.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 710 AM EST WED FEB 25 2015

SCATTERED TO BROKEN CLOUDS ARE IN PLACE ACROSS SOUTHWEST LOWER
MICHIGAN AT 12Z. THE BULK OF THE CLOUDS WERE LOCATED TOWARDS LAKE
MICHIGAN IN A NORTHWEST FLOW. EXPECTING SCATTERED TO BROKEN CLOUDS
TO CONTINUE THROUGH THE DAY...WITH CEILINGS VARYING BETWEEN VFR
AND MVFR.

TONIGHT...SOME LIGHT SNOW WILL SPREAD IN FROM THE WEST...WITH MVFR
CEILINGS BECOMING MORE PREVALENT...ESPECIALLY TOWARDS THE I-94 TAF
SITES FROM KAZO TO KJXN.

WINDS THROUGH THE PERIOD WILL BE FAIRLY LIGHT SHIFTING FROM THE
NORTHWEST TO THE NORTHEAST THE NEXT 24 HOURS.


&&

.HYDROLOGY...
ISSUED AT 224 PM EST TUE FEB 24 2015

CURRENTLY NO SUSPECTED ICE JAMS AND RIVER LEVELS ARE HOLDING RATHER
STEADY. FORECAST CALLS FOR BELOW FREEZING TEMPERATURES INTO NEXT
WEEK WITH OCCASIONAL SNOW OPPORTUNITIES. THE RISK OF FLOODING IS
FAIRLY LIMITED UNTIL A NOTABLE WARM-UP OR RAIN EVENT.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&

$$

UPDATE...WDM
SYNOPSIS...LAURENS
SHORT TERM...LAURENS
LONG TERM...DUKE
AVIATION...DUKE
HYDROLOGY...CAS







000
FXUS63 KGRR 251610
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1110 AM EST WED FEB 25 2015

LATEST UPDATE...
UPDATE

.SYNOPSIS...
ISSUED AT 330 AM EST WED FEB 25 2015

AN ARCTIC AIRMASS WILL REMAIN FIRMLY ENTRENCHED IN THE GREAT LAKES
REGION THROUGH FRIDAY. A WEAK SYSTEM WILL BRING A FEW LIGHT SNOW
SHOWERS TO FAR SOUTHERN LOWER MICHIGAN TONIGHT INTO THURSDAY
MORNING. HIGH PRESSURE WILL BUILD IN TO PRODUCE FAIR BUT COLD
WEATHER THURSDAY THROUGH SATURDAY. TEMPERATURES WILL FINALLY
UNDERGO A GRADUAL MODERATING TREND LATE THIS WEEKEND INTO EARLY
NEXT WEEK.

&&

.UPDATE...
ISSUED AT 1110 AM EST WED FEB 25 2015

THIS IS JUST A QUICK HEADS UP ON MY THINKING FOR TONIGHT. I AM
THINKING IT WILL SNOW TONIGHT (HIGH POP) NEAR AND SOUTH OF I-96.
THIS WILL NOT BE A HEAVY SNOW... MOSTLY AN INCH OR LESS BUT IT
WILL SNOW NONE THE LESS.

AFTER LOOKING AT THE NAM12...RAP13 AND HRRR IT SEEMS TO ME WHAT
WE WILL SEE IS A NARROW BAND OF SNOW DEVELOPING NEAR OR JUST NORTH
OF I-96 AROUND 9 TO 10 PM TONIGHT THAT WILL MOVE SLOWLY SOUTHWARD
(THIS IS SHOWN BY ALL THREE OF THESE MODELS) TO I-94 BY 5 AM. THIS
NARROW BAND IS THE RESULT OF SURFACE FGEN DUE THE RADIATIONAL COOLED
AIR OVER NORTHERN LOWER MICHIGAN COMPARED TO THE CLOUD COVERED AIR
(WHICH WILL NOT COOL) CREATING A THERMAL GRADIENT. THE BEST LIFT
IS JUST ABOVE THE IS NEAR 900 MB WHICH IS IN THE DGZ SO THIS WILL
MAXIMIZE THE SNOWFALL RATES. THIS IS GOING ON UNDER THE ENTRANCE
REGION OF THE UPPER JET SO WE GET DEEP MOISTURE AND DEEP LIFT
(WEAK BUT ALSO IN THE DGZ). AROUND MIDNIGHT THE DGZ OVER GRR IS
FROM 1000 FT TO 12000 FT....MORE THAN DEEP ENOUGH TO HELP THE SNOW
CAUSE. BOTTOM LINE IS I WILL INCREASE THE POP TO OVER 70% OVER THE
SOUTHERN 1/2 OF THE CWA THIS EVENING FOR THIS EVENT.

&&

.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 330 AM EST WED FEB 25 2015

FAIRLY TRANQUIL AND COLD WEATHER IS ANTICIPATED THROUGH THE SHORT
TERM FCST PERIOD. A FEW LIGHT SNOW SHOWERS AND FLURRIES WILL
LINGER INTO THIS MORNING BUT WITH VERY LITTLE TO NO ADDITIONAL
SNOW ACCUMULATION. MOST OF THE DAY WILL BE DRY BUT COLD WITH A MIX
OF SUN AND CLOUDS. MAX TEMPS WILL ONLY REACH 10 TO 15 DEGREES.

A WEAK SYSTEM MOVING ESE FROM THE NORTHERN PLAINS STATES EARLY
THIS MORNING WILL BRING A FEW LIGHT SNOW SHOWERS AND FLURRIES TO
OUR SOUTHERN FCST AREA NEAR TO MAINLY SOUTH OF I-96 TONIGHT INTO
THURSDAY MORNING... WITH VERY LIGHT SNOW ACCUMULATIONS OF UNDER AN
INCH.

BEYOND THAT HIGH PRESSURE WILL BUILD IN TO PRODUCE FAIR BUT COLD
WX THURSDAY AFTERNOON THROUGH FRIDAY. MAX TEMPS THURSDAY WILL
STRUGGLE TO REACH THE UPPER SINGLE DIGITS TO LOWER TEENS AND MINS
THURSDAY NIGHT WILL FALL TO BELOW ZERO ACROSS OUR AREA AS SKIES
CLEAR AND WITH LIGHT WINDS AND EXPANSIVE SNOW COVER IN PLACE. MAX
TEMPS FRIDAY WILL STRUGGLE TO REACH THE LOWER TO MIDDLE TEENS IN
SPITE OF LOTS OF SUN AFTER A VERY COLD START TO THE DAY.

.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 330 AM EST WED FEB 25 2015

UPPER AIR PATTERN SHIFT IS STILL FORECAST TO OCCUR BY THE 00Z MODEL
RUNS DURING THE LONG TERM. THE PERSISTENT UPPER TROUGH IS IN THE
PROCESS OF LIFTING OUT FRIDAY NIGHT. BY EARLY NEXT WEEK A SOUTHWEST
FLOW DEVELOPS ACROSS THE LOWER 48...FROM THE SOUTHWEST U.S. TO THE
GREAT LAKES.

THERE ARE TWO MAIN ITEMS TO KEEP AN EYE ON THROUGH THE PERIOD. THE
FIRST IS THE SNOW EVENT FOR SUNDAY AND SUNDAY NIGHT. IT REMAINS AN
EVENT WITH NO SURFACE LOW TO KEY ON. SNOW IS PRODUCED VIA A WEAK
FRONTAL BOUNDARY SLIPPING THROUGH THE AREA COUPLED WITH AN UPPER
LEVEL SHORT WAVE AND ISENTROPIC LIFT. IT APPEARS TO BE A 2-5 INCH
SNOW POTENTIALLY FOR THE SOUTHERN HALF OF THE FORECAST AREA. WE
STILL HAVE PLENTY OF TIME TO NAIL DOWN THE DETAILS WITH THIS SYSTEM.

THE SECOND SIGNIFICANT FEATURE TO KEEP AN EYE ON IS A SYSTEM NEXT
WEEK IN THE TUESDAY OR WEDNESDAY TIME FRAME. LOW CONFIDENCE IN THIS
TIME FRAME AS THE GFS IS QUICKER...BRINGING A DEEP LOW THROUGH THE
AREA ON TUESDAY. THE ECMWF AND CANADIAN ARE SLOWER AND BRING THE
SYSTEM THROUGH ON WEDNESDAY. AT THIS POINT...SIDING WITH THE ECWMF
AND CANADIAN AND THE SLOWER SYSTEM. THE SYSTEM TAPS GULF MOISTURE IN
DEEP SOUTHERLY FLOW. PRECIPITATION TYPE ISSUES COME INTO PLAY
TUESDAY NIGHT IN THE ECMWF/CANADIAN SOLUTIONS WITH +4 TO +6 850MB
AIR SURGING IN FROM THE SOUTH. THESE VALUES WOULD YIELD RAIN AS THE
PRECIP TYPE ALONG I94. MODELS ARE HAVING ISSUES WITH THIS SYSTEM AS
ITS DRIVEN BY A WAVE EJECTING OUT OF THE SOUTHWEST U.S. TROUGH. WE
WILL BE MONITORING TRENDS WITH THIS SYSTEM IN THE COMING DAYS.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 710 AM EST WED FEB 25 2015

SCATTERED TO BROKEN CLOUDS ARE IN PLACE ACROSS SOUTHWEST LOWER
MICHIGAN AT 12Z. THE BULK OF THE CLOUDS WERE LOCATED TOWARDS LAKE
MICHIGAN IN A NORTHWEST FLOW. EXPECTING SCATTERED TO BROKEN CLOUDS
TO CONTINUE THROUGH THE DAY...WITH CEILINGS VARYING BETWEEN VFR
AND MVFR.

TONIGHT...SOME LIGHT SNOW WILL SPREAD IN FROM THE WEST...WITH MVFR
CEILINGS BECOMING MORE PREVALENT...ESPECIALLY TOWARDS THE I-94 TAF
SITES FROM KAZO TO KJXN.

WINDS THROUGH THE PERIOD WILL BE FAIRLY LIGHT SHIFTING FROM THE
NORTHWEST TO THE NORTHEAST THE NEXT 24 HOURS.


&&

.HYDROLOGY...
ISSUED AT 224 PM EST TUE FEB 24 2015

CURRENTLY NO SUSPECTED ICE JAMS AND RIVER LEVELS ARE HOLDING RATHER
STEADY. FORECAST CALLS FOR BELOW FREEZING TEMPERATURES INTO NEXT
WEEK WITH OCCASIONAL SNOW OPPORTUNITIES. THE RISK OF FLOODING IS
FAIRLY LIMITED UNTIL A NOTABLE WARM-UP OR RAIN EVENT.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&

$$

UPDATE...WDM
SYNOPSIS...LAURENS
SHORT TERM...LAURENS
LONG TERM...DUKE
AVIATION...DUKE
HYDROLOGY...CAS








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