Area Forecast Discussion
Issued by NWS Grand Rapids, MI

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS63 KGRR 042344
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
744 PM EDT WED MAY 4 2016

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 300 PM EDT WED MAY 4 2016

RAIN WILL CONTINUE INTO EARLY TONIGHT BEFORE ENDING OVERNIGHT.
MOST LOCATIONS STAY DRY ON THURSDAY BUT SOME POP UP SHOWERS ARE
POSSIBLE MAINLY ALONG AND EAST OF U.S. 131. A WARM AND DRY DAY
FRIDAY TRANSITIONS INTO A WET SATURDAY AS A COLD FRONT MOVES
THROUGH. MOTHER`S DAY WILL FEATURE COOLER TEMPERATURES ALONG WITH
POSSIBLY A FEW SHOWERS.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 300 PM EDT WED MAY 4 2016

MUCH OF WESTERN AND CENTRAL LOWER MI WILL BE STUCK IN THE
DEFORMATION ZONE OF A SLOWLY DEPARTING LOW PRESSURE SYSTEM THIS
EVENING INTO TONIGHT. THE PIVOT REGION IS RIGHT
OVERHEAD...ALLOWING A COLD RAIN TO PERSIST RIGHT INTO THE FIRST
HALF OF TONIGHT. THIS RAIN FINALLY ENDS FROM NORTH TO SOUTH INTO
THE OVERNIGHT HOURS. THE HIGHEST STORM TOTALS WILL BE FOUND FROM
GRAND RAPIDS UP TO BIG RAPIDS...REED CITY...AND HARRISON. AMOUNTS
OVER AN INCH ARE EXPECTED IN SOME OF THESE AREAS AND IN FACT HAVE
ALREADY BEEN MEASURED IN SOME CASES. EXPECT SOME PONDING ON THE
ROADS INTO TONIGHT ALONG WITH SOME STANDING WATER IN LOW LYING
AREAS.

WE COULD POP A FEW SHOWERS THURSDAY AFTERNOON AS THE CU FIELD
DEVELOPS AND LOW LEVEL CONVERGENCE IS DEPICTED BY THE MODELS. THE
WRF ARW AND NAM 4KM SUPPORT ISOLATED SHOWERS NEAR AND EAST OF
U.S. 131 EARLY AFTERNOON AND EVEN THE GFS IS PRODUCING SOME LIGHT
PRECIP IN A SIMILAR AREA. GFS BUFKIT SOUNDINGS FOR GRR SHOW RATHER
SHALLOW CU BUT PERHAPS ENOUGH LIFT BELOW AND WITHIN THE CLOUD
LAYER COULD SUPPORT SOME ISOLATED SHOWERS. THUNDER IS NOT
EXPECTED.

TEMPS SHOULD BOTTOM OUT IN THE UPPER 30S TO LOW 40S FRIDAY MORNING
SO FROST LOOKS UNLIKELY EXCEPT PERHAPS INTERIOR CENTRAL LOWER
MI...WHERE SOME MID 30S ARE POSSIBLE (LOCALLY COOLER). FRIDAY
ITSELF SHOULD BE TRANQUIL AND MILD WITH HIGHS HITTING THE LOW 70S
AWAY FROM THE LAKE.

.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 300 PM EDT WED MAY 4 2016

MEDIUM RANGE GUIDANCE TRENDS THE PAST COUPLE OF DAYS CONTINUE TO
SUGGEST A FASTER COLD FRONTAL PASSAGE FOR SATURDAY SUCH THAT THE
COLD FRONT SHOULD BE THROUGH OUR FCST AREA BY MIDDAY. AS SUCH THE
BEST CHC FOR SHOWERS WILL COME IN THE MORNING. ALSO GIVEN THE FASTER
FRONTAL TIMING THE THREAT FOR CONVECTION SATURDAY IS MUCH LOWER.

A SLIGHTLY COOLER AIRMASS WILL BRIEFLY MOVE IN SATURDAY NIGHT
THROUGH SUNDAY NIGHT AND A FEW DIURNALLY DRIVEN SHOWERS ARE POSSIBLE
ON SUNDAY. A TROUGH OF LOW PRESSURE MOVING THROUGH SUNDAY WILL ALSO
LIKELY BRING A FEW SHOWERS.

DRY WEATHER IS ANTICIPATED FOR MONDAY BEFORE ISENTROPIC UPGLIDE
NORTH OF A WARM FRONT DRAPED ACROSS THE OHIO VALLEY REGION BRINGS
POTENTIAL FOR SHOWERS MONDAY NIGHT THROUGH MIDWEEK.

A COUPLE OF ROUNDS OF STEADIER RAINFALL ARE POSSIBLE NORTH OF THE
WARM FRONT TUESDAY AND WEDNESDAY. THIS IS LARGELY CONTINGENT ON
FRONTAL POSITION BY THEN AND THERE ARE LARGER MEDIUM RANGE GUIDANCE
DISCREPANCIES REGARDING THE EVOLUTION OF THE WX PATTERN AND
FRONTAL POSITIONS BY THEN.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 737 PM EDT WED MAY 4 2016

IMPACTS TO AVIATORS LOOK LIKELY FOR THIS EVENING...ESPECIALLY
SOUTH AND EAST OF KMKG. LOW LEVEL MOISTURE REMAINS HIGH FOR MUCH
OF THE AREA WITH LOW PRESSURE IN THE VICINITY. THIS LOW MOVES OFF
TO THE EAST LATER TONIGHT. NORTHERLY WINDS ON THE BACKSIDE WILL
EVENTUALLY DRAW DOWN ENOUGH DRY AIR TO SEND THE TAFS TO
VFR...BUT IT WILL TAKES SOME TIME...ESPECIALLY FOR KAZO AND KBTL
WHO MAY NOT GO VFR TIL THU AFTN. KGRR LOOKS TO BE ON THE EDGE OF
THE LOW CLOUDS/IFR TONIGHT. WILL NEED TO MONITOR THIS CLOSELY. I
DID FEATURE A FEW HOURS OF IFR FOR KGRR TO START...BUT TRENDED
TOWARD MVFR WITH THE NORTHERLY FLOW PERSISTING DURING THE EVENING.

&&

.MARINE...
ISSUED AT 300 PM EDT WED MAY 4 2016

GALE WARNINGS CONTINUE THOUGH CONDITIONS WILL BE MOST IMPACTFUL
FROM HOLLAND TO THE SOUTH. NORTH OF HOLLAND...GALE CONDITIONS WILL
BE SPORADIC IT APPEARS SO THIS MAY BE A RATHER MARGINAL SITUATION.
NEVERTHELESS...CONDITIONS WILL BE ROUGH OUT THERE WITH WAVE
HEIGHTS OF 5 TO 10 FEET BEING OBSERVED TODAY AND WILL CONTINUE
INTO THE EVENING.


&&

.HYDROLOGY...
ISSUED AT 1155 AM EDT WED MAY 4 2016

RIVER FLOOD ADVISORIES ARE CURRENTLY POSTED FOR SYCAMORE CREEK NEAR
HOLT AND THE GRAND RIVER AT IONIA. BOTH ARE RISING BACK ABOVE
BANKFULL LEVELS AND SHOULD CREST THURSDAY OR FRIDAY BELOW FLOOD
STAGE. A FEW OTHER SITES ARE FORECAST TO CREST AROUND BANKFULL
THURSDAY OR FRIDAY.

RAINFALL TOTALS OF UP TO A HALF INCH FELL THROUGH THIS MORNING WITH
ANOTHER HALF INCH TO INCH EXPECTED THROUGH TONIGHT. THIS SHOULD HELP
TO KEEP RIVER LEVELS ELEVATED. THUNDERSTORMS ARE POSSIBLE
SATURDAY... SO RIVERS WILL NEED TO BE MONITORED INTO EARLY NEXT
WEEK.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...GALE WARNING UNTIL 2 AM EDT THURSDAY FOR LMZ844>849.

&&

$$

SYNOPSIS...HOVING
SHORT TERM...HOVING
LONG TERM...LAURENS
AVIATION...MJS
HYDROLOGY...63
MARINE...HOVING



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.