Area Forecast Discussion
Issued by NWS Grand Rapids, MI

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000
FXUS63 KGRR 171929
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
329 PM EDT SUN AUG 17 2014

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

.SYNOPSIS...
ISSUED AT 329 PM EDT SUN AUG 17 2014

MAINLY DRY CONDITIONS ARE EXPECTED TONIGHT OUTSIDE OF A FEW EVENING
RAIN SHOWERS TOWARDS INTERSTATE 94. THE NEXT CHANCES FOR RAIN WILL
COME MONDAY NIGHT INTO TUESDAY AS A LOW PRESSURE SYSTEM MOVES OUR
DIRECTION FROM THE NORTHERN PLAINS. SHOWERS AND STORMS ARE IN THE
FORECAST DURING THIS TIME FRAME. THE BEST CHANCE FOR RAIN WILL COME
LATE MONDAY NIGHT AND ESPECIALLY ON TUESDAY. TEMPERATURES WILL BE
NEAR NORMAL THE NEXT FEW DAYS WITH HIGHS IN THE UPPER 70S TO AROUND
80.

&&

.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 329 PM EDT SUN AUG 17 2014

MAIN FOCUS OF THE SHORT TERM IS ON PRECIPITATION CHANCES DURING THE
MONDAY NIGHT THROUGH TUESDAY NIGHT TIME FRAME. MAINLY DRY CONDITIONS
ARE EXPECTED UNTIL THEN BOTH TONIGHT AND ON MONDAY. THERE WILL BE A
FEW DIURNALLY DRIVEN SHOWERS TOWARDS I-94 LATE THIS AFTERNOON AND
EVENING...BUT THIS ACTIVITY SHOULD WIND DOWN FAIRLY QUICK BETWEEN
7-10PM.

A GOOD PUSH OF 850MB DEW POINTS OCCURS MONDAY NIGHT WITH THE DEEPEST
MOISTURE THEN OVERHEAD ON TUESDAY. THIS IS IN ADVANCE OF A LOW
MOVING OUR DIRECTION FROM MINNESOTA. HAVE CHANCES FOR SHOWERS AND A
FEW STORMS MONDAY NIGHT (30-50 PCT MAINLY) INCREASING TO LIKELY ON
TUESDAY (60-70 PCT). THE UPPER SHORTWAVE DRIVING THE SYSTEM WILL
SLOWLY WORK THROUGH THE REGION MONDAY NIGHT THROUGH TUESDAY NIGHT.

THE LOW LEVEL JET IS NOT IMPRESSIVE THROUGH THE PERIOD PEAKING AT
20-25 KNOTS MONDAY NIGHT. 850MB MOISTURE TRANSPORT IS NOT HIGH
EITHER. THE MOISTURE TRANSPORT SHOULD BE SUFFICIENT ENOUGH THOUGH
FOR SHOWERS/STORMS...BUT NOT EXPECTING SEVERE STORMS OR WIDESPREAD
HEAVY RAINS. RAINFALL THROUGH TUESDAY SHOULD BE ON THE ORDER TO A
QUARTER TO A HALF INCH IN MANY AREAS. THE PRECIP SHOULD TAPER OFF
SOME TUESDAY NIGHT AS THE MOISTURE TRANSPORT WINDS DOWN AND WE LOSE
ANY DIURNAL COMPONENT.

AS FOR TONIGHT...EXPECTING A SURGE OF STRATUS AGAIN...COVERING MOST
OF THE CWA BY MORNING. WINDS JUST OFF THE DECK OF 15-20 KNOTS AROUND
1000FT SHOULD PRECLUDE MUCH IN THE WAY OF FOG.

.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 329 PM EDT SUN AUG 17 2014

WE/LL HAVE SEVERAL OPPORTUNITIES FOR RAIN DURING THE LONG TERM. THE
FIRST CHANCE IS WEDNESDAY...BUT MAINLY OVER THE EASTERN CWA. LOW
PRESSURE OVER NE LOWER WILL MOVE TO NEAR DETROIT WHICH WOULD PLACE
THE HIGHEST CHANCE FOR PCPN EAST OF THE CWA...BUT PERHAPS JUST CLIP
THE EASTERN CWA.

A WARM FRONT THEN MOVES NORTHEAST TOWARD THE CWA THURSDAY. BEST
MOISTURE TRANSPORT STAYS SOUTH OF THE CWA. HOWEVER WITH LI/S NEAR
-2C AND A LOW MOVING ACROSS NORTHERN INDIANA...WE/LL KEEP THE
MENTION OF TSRA IN THE GRIDS. THE FRONTAL BOUNDARY WON/T MOVE TOO
FAR SOUTH FRIDAY BEFORE MIGRATING NORTH SATURDAY/SUNDAY IN ADVANCE
OF A STRONGER COLD FRONT. WE MAY HAVE OUR BEST CHANCE OF RAIN LATE
SATURDAY INTO SUNDAY AS THE COLD FRONT MOVES THROUGH THE CWA.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 142 PM EDT SUN AUG 17 2014

A WEAK FRONTAL BOUNDARY EXTENDS FROM GRAND HAVEN TO DETROIT. NOT
SURPRISINGLY...THAT/S WHERE WE FIND THE LOWEST CIGS/VSBYS. LOOK
FOR STRATOCU AND VSBYS TO RISE SLOWLY THIS AFTERNOON...BUT STILL
MAINTAIN MVFR CONDITIONS ACROSS THE SRN TAF SITES. THE FRONTAL
BOUNDARY WON/T MOVE MUCH TONIGHT. AS SUCH...LIFR FOG/VSBYS POSSIBLE
LATE TONIGHT OVER THE SRN TAF SITES IN A WEAKLY MIXED ENVIRONMENT.

&&

.MARINE...
ISSUED AT 329 PM EDT SUN AUG 17 2014

WINDS HAVE COME A BIT MORE ONSHORE THIS AFTERNOON WITH WAVE HEIGHTS
AROUND 2 FEET AT MOST OF THE NEARSHORE BUOYS. THE MID LAKE BUOY IS
AROUND 3 FEET. EXPECT NORTHERLY WINDS THIS AFTERNOON AND EARLY
EVENING TO BRING 2 TO POSSIBLY 4 FOOTERS INTO THE NEARSHORE WATERS
BEFORE WINDS BECOME OFFSHORE AGAIN AROUND SUNSET OR SHORTLY
THEREAFTER.

WINDS AND WAVES OF 2 FEET OR LESS ARE THEN EXPECTED FROM TONIGHT
INTO TUESDAY IN THE NEARSHORE WATERS. SOUTHERLY WINDS WILL INCREASE
MONDAY NIGHT INTO TUESDAY AHEAD OF A LOW PRESSURE SYSTEM ADVANCING
OUR DIRECTION. GIVEN ITS A WARM AIR ADVECTION WIND AND A FAIRLY
SHORT DURATION NOT EXPECTING BIG IMPACTS.

&&

.HYDROLOGY...
ISSUED AT 154 PM EDT SUN AUG 17 2014

ONE TO OVER 2 INCHES OF RAIN FELL OVER PARTS OF THE MACATAWA AND
KALAMAZOO RIVER BASINS OVER THE LAST 24 HOURS. QUICK RISES ARE
POSSIBLE IN THESE BASINS... THOUGH NO FLOODING IS EXPECTED. LITTLE
RAINFALL IS EXPECTED THROUGH MONDAY... WHICH WILL ALLOW RIVER LEVELS
TO RECEDE.

ELSEWHERE... RIVERS ARE RUNNING A LITTLE ABOVE NORMAL BUT ARE STILL
FAR BELOW BANK FULL. MOSTLY LIGHT PRECIPITATION IS POSSIBLE MONDAY
NIGHT THROUGH THURSDAY... WITH TOTALS EXPECTED TO END UP MOSTLY
AROUND AN INCH. THIS SHOULD LEAD TO SLOW RISES ON THE AREAS RIVER
SYSTEMS WITH PEAK LEVELS BELOW FLOOD STAGE OCCURRING BY THE END OF
THE WEEK.

&&

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

$$

SYNOPSIS...DUKE
SHORT TERM...DUKE
LONG TERM...93
AVIATION...93
HYDROLOGY...63
MARINE...DUKE








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