Area Forecast Discussion
Issued by NWS Grand Rapids, MI

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000
FXUS63 KGRR 300211
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1011 PM EDT SAT AUG 29 2015

LATEST UPDATE...
UPDATE/MARINE

.SYNOPSIS...
ISSUED AT 303 PM EDT SAT AUG 29 2015

THE SCATTERED SHOWERS WILL GRADUALLY END OVERNIGHT...BUT ONE CAN
EXPECT SOME AREAS OF FOG BY SUNDAY MORNING.  AFTER THE FOG BURNS
OFF...THE REST OF SUNDAY WILL BE DRY AND MILD WITH HIGHS IN THE
UPPER 70S TO AROUND 80.  MONDAY ALSO LOOKS DRY AND WARMER WITH HIGHS
IN THE LOW TO MID 80S.

THE REST OF NEXT WEEK APPEARS MOSTLY DRY...BUT AN ISOLATED SHOWER OR
STORM CAN NOT BE RULED OUT WEDNESDAY NIGHT THROUGH THURSDAY NIGHT.
IT SHOULD BE A WARM WEEK WITH DAYTIME HIGHS REMAINING IN THE 80S.

&&

.UPDATE...
ISSUED AT 1005 PM EDT SAT AUG 29 2015

BASED ON RADAR TRENDS THE FORECAST WAS UPDATED TO FEATURE SOME
HIGHER POPS MAINLY SOUTH OF INTERSTATE 96. AS FOR THUNDERSTORMS I
DOWNPLAYED THE RISK DESPITE SOME INSTABILITY AROUND. SO FAR THE
CELLS HAVE REMAIN FAIRLY SHALLOW. I DID FEATURE FOG DEVELOPING
WITH THE VERY MOIST LOW LEVELS IN PLACE AND LIGHT WINDS.

&&

.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 303 PM EDT SAT AUG 29 2015

THE SHOWERS AND A FEW STORMS WILL BE WINDING DOWN THROUGH THE NIGHT.
AFTER SOME SUNDAY MORNING FOG...THE REST OF THE SHORT TERM LOOKS
QUIET.

A WEAKENING FRONT HAS MOVED SOUTH OF THE CWA WITH SOME LEFT OVER
SHOWERS AND STORMS RIDING ALONG THE NORTH SIDE OF THE FRONT.  THE
RIGHT ENTRANCE REGION OF THE UPPER JET WILL STILL BE OVER THE
SOUTHERN CWA INTO THE EVENING...MAINTAINING THE SHOWERS...BUT THEN
IT MOVES OFF TO THE EAST.  THE MAJORITY OF THE PCPN SHOULD BE
EXITING THE CWA SHORTLY AFTER MIDNIGHT.  NOT EXPECTING MUCH CLEARING
BEHIND THE PCPN TONIGHT...BUT WINDS WILL BE LIGHT AND DEW POINTS
HIGH...SO EXPECT FOG LATE TONIGHT INTO SUNDAY MORNING.  BUT WITH THE
CLOUD COVER...NOT EXPECTING IT TO BECOME TOO DENSE OVER MOST OF THE
AREA.

CLEARING ON SUNDAY MAY BE SLOW AS THE LOW LEVEL MOISTURE WILL BE
TRAPPED UNDER AN INVERSION...ALONG WITH LIGHT WINDS.  THE THINKING
IS THE HIGH SUN ANGLE WITH HELP BURN THESE CLOUDS OFF.  BUT IT MAY
TAKE WELL INTO THE AFTERNOON UNTIL THIS HAPPENS...AND PERHAPS NOT
UNTIL THE EVENING FOR THE SE CWA.

THE REMAINDER OF THE SHORT TERM WILL BE DRY WITH A GRADUALLY WARMING
TREND AS UPPER RIDGING MOVES IN.  HIGHS SUNDAY UPPER 70S TO AROUND
80...AND WITH MORE SUNSHINE MONDAY WILL SEE LOW TO MID 80S AWAY FROM
THE LAKE.

.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 303 PM EDT SAT AUG 29 2015

THE THEME OF THE LONG TERM IS ABOVE AVERAGE TEMPS WITH A LOW CHANCE
OF A SHOWER/STORM EACH DAY. MOST OF THE TIME WE WILL SEE QUITE A BIT
OF SUNSHINE DURING THE DAY WITH DRY CONDITIONS. THIS WILL ALL OCCUR
AS WE STILL EXPECT UPPER RIDGING TO BUILD OVER THE ERN PORTION OF
NORTH AMERICA AS A STRONG TROUGH BECOMES ESTABLISHED ACROSS THE WRN
PORTION OF THE CONTINENT.

TEMPS SHOULD BE GENERALLY IN THE MID TO UPPER 80S EACH DAY WITH H850
TEMPS IN THE UPPER TEENS THROUGH MUCH OF THE PERIOD. THE THREAT OF A
SHOWER OR STORM IS A BIT LOWER FOR MID WEEK COMPARED TO THE FCST
YESTERDAY AS THE WAVE OF INTEREST IS SHOWN TO DAMPEN OUT QUICKER AND
BE LESS OF A FACTOR. WE WILL HAVE A GENERAL SRLY FLOW IN PLACE IN
THE LOWER LEVELS ADVECTING FAIRLY MOIST AIR INTO THE AREA. ENOUGH
INSTABILITY COULD BUILD AWAY FROM LAKE MICHIGAN EACH DAY THAT A
SHOWER/STORM COULD POP WITH ANY KIND OF MESOSCALE BOUNDARY THAT MAY
BE PRESENT.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 742 PM EDT SAT AUG 29 2015

LOW LEVEL MOISTURE IS ALREADY HIGH AND WE WILL BE COOLING OFF
GRADUALLY TONIGHT. THUS I FEATURED THE FOG AND LOWER CLOUDS
DEVELOPING SOONER. IT WILL NOT BE UNTIL MID TO LATE MORNING BEFORE
WE SEE SOME IMPROVEMENT. AVIATORS WITH FLIGHT PLANS TONIGHT SHOULD
MONITOR TRENDS CLOSELY. LIGHT RAIN/DRIZZLE WILL ALSO BE AROUND TO
START THE NIGHT...BUT THE RISK FOR THUNDER IS TOO LOW TO INCLUDE
IN THE FORECAST DESPITE WEAK INSTABILITY.


&&

.MARINE...
ISSUED AT 1005 PM EDT SAT AUG 29 2015

WILL NEED TO MONITOR THE POTENTIAL FOR DENSE FOG OVER THE
NEARSHORE WATERS. MOIST LOW LEVELS COULD LEAD TO FOG DEVELOPMENT.
CAMS JUST BEFORE SUNSET DID NOT SHOW MUCH IN THE WAY OF FOG. WILL
KEEP THE AREAS OF FOG GOING FOR NOW. THE PRESSURE GRADIENT REMAINS
RELATIVELY WEAK SO WINDS AND RESULTING WAVES SHOULD REMAIN LOW
INTO MONDAY.

&&

.HYDROLOGY...
ISSUED AT 139 PM EDT SAT AUG 29 2015

MOST LOCATIONS SAW LESS THAN A HALF INCH OF RAIN LAST NIGHT INTO
TODAY. THIS SHOULD NOT CAUSE HYDRO CONCERNS.  MUCH OF NEXT WEEK
LOOKS LARGELY DRY.

&&

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

$$

UPDATE...MJS
SYNOPSIS...JK
SHORT TERM...JK
LONG TERM...NJJ
AVIATION...MJS
HYDROLOGY...63/JK MARINE...JK
MARINE...MJS



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