Area Forecast Discussion
Issued by NWS Grand Rapids, MI

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FXUS63 KGRR 261719
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
119 PM EDT TUE APR 26 2016

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 330 AM EDT TUE APR 26 2016

CLOUDY AND CHILLY WEATHER CAN BE EXPECTED TODAY BEHIND AN EXITING
LOW PRESSURE SYSTEM. HIGH PRESSURE WILL BUILD IN TONIGHT AND BRING
CLEARING SKIES WITH SOME PATCHY FROST POSSIBLE. OUR NEXT CHANCE OF
RAIN WILL COME WEDNESDAY NIGHT AND THURSDAY... WITH TEMPERATURES
REMAINING ON THE CHILLY SIDE.

&&

.UPDATE...
ISSUED AT 951 AM EDT TUE APR 26 2016

I EXPUNGED THE FOG ADVISORY SINCE ALL REPORTING SITES NOW HAVE
VISIBILITIES OVER 1/4 MILE. THE LOW CLOUDS WILL CONTINUE MOST OF
THE DAY BUT THERE SHOULD BE CLEARING TOWARD EVENING.

UPDATE ISSUED AT 609 AM EDT TUE APR 26 2016

WILL GO AHEAD AND ISSUE A DENSE FOG ADVISORY FOR OUR SOUTHERN
THREE ROWS OF COUNTIES THROUGH 11AM. A BAGGY GRADIENT JUST BEHIND
THE SURFACE LOW...LAST NIGHT/S RAIN AND SOME LINGERING HIGHER DEW
POINTS ARE CONTRIBUTING TO THE FOG. THE FOG SHOULD SPREAD INTO THE
I-94 COUNTIES THROUGH 800AM AS THE STRATUS TRUDGES SOUTH.

EXPECTING IMPROVEMENT THROUGH THE MORNING AS NORTH AND NORTHEAST
WINDS KICK IN AND ADVECT IN DRIER DEW POINTS. BY MID MORNING AN
IMPROVEMENT SHOULD BE NOTED. RAN THE HEADLINE THROUGH 11AM HOWEVER
TO GIVE US A BUFFER IF IT LINGERS.

&&

.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 330 AM EDT TUE APR 26 2016

MOIST LOW LEVEL NORTHEAST FLOW WILL LEAD TO WIDESPREAD LOW CLOUDS
TODAY. THIS WILL HOLD TEMPS DOWN AND HIGHS OF ONLY 50-55 ARE
EXPECTED. SOME PATCHY FOG/DRIZZLE POSSIBLE THIS MORNING BEFORE
CEILINGS LIFT A BIT THIS AFTERNOON.

OTHERWISE A PERIOD OF DRY WEATHER LIKELY TODAY THROUGH WEDNESDAY AS
SKINNY BUT HIGH AMPLITUDE RIDGE ALOFT DEVELOPS IN BETWEEN DEEPENING
UPPER TROUGH OVER QUEBEC AND THE DEEP TROUGH PROGRESSING FROM THE
ROCKIES INTO THE CENTRAL PLAINS.

LOW CONFIDENCE REGARDING EXTENT/TIMING OF CLEARING TONIGHT AND ALSO
HOW MUCH THE WINDS DROP OFF... BUT SOME PATCHY FROST APPEARS
POSSIBLE TOWARD MORNING.

AFOREMENTIONED CENTRAL PLAINS UPPER TROUGH PIVOTS NORTHEAST
WEDNESDAY NIGHT AND SHEARS OUT OVERHEAD ON THURSDAY. THIS SHOULD
SEND CLOUDS AND SHOWERS BACK INTO THE AREA FROM THE SOUTHWEST.
HOWEVER RAIN AMOUNTS SHOULD BE ON THE LIGHT SIDE AS WE REMAIN IN THE
COOL AIR MASS WELL NORTH OF THE SFC BOUNDARY.

.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 330 AM EDT TUE APR 26 2016

TWO SYSTEMS TO DEAL WITH IN THE LONG TERM. THE FIRST OF WHICH WILL
BE AFFECTING THE AREA AT THE START...ON THURSDAY NIGHT. THE SECOND
WILL MOVE TOWARD THE AREA OVER THE WEEKEND AND LINGER INTO EARLY
NEXT WEEK.

RAIN CHANCES EXIST THURSDAY NIGHT AS A PLAINS SURFACE LOW MOVES EAST
AND WEAKENS ACROSS THE OHIO VALLEY. GIVEN THE WEAKENING NATURE OF
THE LOW...CHANCES ARE NOT HIGH AND HAVE MATCHED NEIGHBORS WITH VERY
LOW POPS ON THE ORDER OF 20 PCT.

A DRY PERIOD LOOKS TO EXTEND FROM LATE THURSDAY NIGHT THROUGH FRIDAY
AND INTO SATURDAY AS SURFACE HIGH PRESSURE WILL BE NOSING INTO THE
AREA FROM THE NORTH. A DRY EASTERLY FLOW OF AIR WILL LIKELY ERODE
PRECIPITATION THAT TRIES TO PUSH IN WITH THE NEXT SYSTEM AT LEAST
INITIALLY.

FEEL LIKE BEST CHANCES FOR PRECIPITATION WITH THE WEEKEND SYSTEM
WILL COME SUNDAY INTO SUNDAY NIGHT AS THE LOW LIFTS INTO THE REGION.
QUARTER TO HALF INCH RAIN TOTALS APPEAR POSSIBLE WITH THIS SYSTEM.
THE ECMWF IS STILL FURTHER NORTH WITH THE LOW AS COMPARED TO THE
GFS. SO...SOME UNCERTAINTY CONTINUES OUT ON DAY 6 AND DAY 7.

FAIRLY TYPICAL SPRING TIME WEATHER OVERALL...WITH PERIODIC CHANCES
FOR RAIN AND SEASONABLE TEMPERATURES IN THE UPPER 50S TO LOWER 60S.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 114 PM EDT TUE APR 26 2016

THE IFR CONDITIONS HAVE BEEN SLOW TO BREAK UP THIS MORNING. TRENDS
HAVE DEVELOPED THOUGH...WHICH SUPPORT CONDITIONS GOING TO MVFR
THROUGH MID AFTERNOON. CEILING HEIGHTS HAVE BEEN INCREASING
SLOWLY...PLUS THE SURFACE HUMIDITY HAS BEEN DROPPING OFF. THIS HAS
BEEN REFLECTED IN THE VISIBILITY OBSERVATIONS...WITH NEARLY ALL
SITES OVER 6SM.

VFR CONDITIONS ARE EXPECTED BY 00Z...WITH THE SKIES CLEARING OUT
OVERNIGHT. THIS WILL BE DUE TO A DRIER AIRMASS FILTERING IN FROM
THE NORTHEAST.

&&

.MARINE...
ISSUED AT 330 AM EDT TUE APR 26 2016

MAINLY OFFSHORE FLOW THE NEXT DAYS SHOULD KEEP WAVES BELOW ADVISORY
CRITERIA. HOWEVER WAVES TODAY NEAR BIG SABLE COULD BE NEAR 4 FEET
WITH NORTHEAST WINDS 15-20 KTS.


&&

.HYDROLOGY...
ISSUED AT 330 AM EDT TUE APR 26 2016

LOCALIZED RAINFALL AMOUNTS IN EXCESS OF TWO INCHES OCCURRED LAST
NIGHT... SO SOME AREAS OF STANDING WATER MAY LINGER THIS MORNING.
SOME OF THE SMALLER RIVERS/STREAMS MAY SEE RISES BUT PROBABLY NOT
MUCH IMPACT ON THE LARGER RIVERS DUE TO THE ISOLATED NATURE OF THE
HEAVIER RAINS.

&&

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

$$

UPDATE...WDM
SYNOPSIS...MEADE
SHORT TERM...MEADE
LONG TERM...DUKE
AVIATION...MJS
HYDROLOGY...MEADE
MARINE...MEADE



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