Area Forecast Discussion
Issued by NWS Grand Rapids, MI

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FXUS63 KGRR 080205
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1005 PM EDT TUE JUL 7 2015

LATEST UPDATE...
MARINE

.SYNOPSIS...
ISSUED AT 329 PM EDT TUE JUL 7 2015

A COLD FRONT IS PROGRESSING OFF TO THE EAST OF LOWER MICHIGAN THIS
EVENING ALLOWING COOLER AND DRIER AIR TO FILTER IN ON NORTHERLY
WINDS. IN FACT...LOWS WILL DIP INTO THE 40S ACROSS CENTRAL LOWER
MICHIGAN TONIGHT. HIGH PRESSURE SLIDING OUR DIRECTION FROM THE
NORTHERN PLAINS WILL BRING FAIR WEATHER FROM TONIGHT THROUGH
WEDNESDAY. THE NEXT WEATHER MAKER FOR SOUTHWEST LOWER MICHIGAN WILL
BRUSH THE SOUTHERN GREAT LAKES WEDNESDAY NIGHT INTO THURSDAY WITH
RAIN EXPECTED ALONG AND SOUTH OF INTERSTATE 96. HIGHS BOTH WEDNESDAY
AND THURSDAY WILL BE BELOW NORMAL FOR THIS TIME OF YEAR HOLDING IN
THE 70S.

&&

.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 329 PM EDT TUE JUL 7 2015

MAIN FOCUS OF THE SHORT TERM IS ON THE PRECIPITATION EVENT WEDNESDAY
NIGHT INTO THURSDAY AS A LOW MOVES ACROSS NORTHERN INDIANA AND OHIO.
OTHERWISE FAIR WEATHER IS EXPECTED IN THE SHORT TERM.

ALL OF THE SHORT TERM OPERATIONAL MODELS...ECMWF...NAM...GFS AND
CANADIAN GEM ALL TAKE THE SURFACE LOW WEDNESDAY NIGHT INTO THURSDAY
ACROSS PORTIONS OF NORTHERN INDIANA AND OHIO. SO...SOLID CONSENSUS
IN A PRECIP EVENT FOR OUR SOUTH. THE SURFACE LOW IS WEAK IN DEPTH
BUT APPEARS COMPACT AND SOMEWHAT POTENT. THE LOW IS ASSOCIATED WITH
A MID LEVEL SHORTWAVE THAT IS CURRENTLY SEEN MOVING EAST ACROSS THE
TEXAS PANHANDLE. WATER VAPOR SHOWS SOME TROPICAL CONNECTION WITH THE
SHORTWAVE AND PWATS ARE AROUND 2 INCHES AS IT PASSES ACROSS FAR
SOUTHERN LOWER MICHIGAN WHICH IS ABOVE NORMAL EVEN FOR EARLY JULY.

MODELS SEEM TO BE STRUGGLING WITH THE AMOUNT OF PRECIP ACROSS THE
FAR SOUTH...BUT THERE IS SOME HINTS THAT IT COULD BE ON THE HEAVIER
SIDE. LATER FORECASTS WILL BEGIN TO NAIL THIS DOWN AS THE WAVE
APPROACHES. AT THIS POINT HAVE LIKELY POPS ACROSS THE SOUTH WITH A
PRETTY TIGHT GRADIENT AS YOU HEAD NORTH ACROSS THE CWA. THE FAR
NORTHERN CWA WILL PROBABLY NOT SEE MUCH IN THE WAY OF RAINFALL.

OTHERWISE...EXPECT DECREASING CLOUDS TONIGHT AS THE DIURNAL CUMULUS
GRADUALLY FADES AND ADVECTS SOUTHWARD. WEDNESDAY WILL BE A PARTLY
CLOUDY DAY AS WE SEE CUMULUS DEVELOP ONCE AGAIN ACROSS THE LOWER
PENINSULA. THURSDAY NIGHT LOOKS DRY WITH QUIET WEATHER AS WELL AS
THE COMPACT LOW WILL BE HEADED EAST.

.LONG TERM...(FRIDAY THROUGH TUESDAY) ISSUED AT 329 PM EDT TUE JUL 7
2015

MID LEVEL FLOW WILL TRANSITION THIS WEEKEND AS THE HIGH OVER THE
SOUTHEASTERN STATES MIGRATES TO THE SOUTHERN ROCKIES.  MODELS ARE IN
FAIRLY GOOD AGREEMENT BRINGING WARM FRONT THROUGH THE REGION
SATURDAY...WHICH WILL RESULT IN A GOOD CHANCE OF SHOWERS AND STORMS.
ONCE THE MID LEVEL RIDGE BECOMES ESTABLISHED OUT WEST...PIECES OF
ENERGY WILL MOVE THROUGHOUT THE GREAT LAKES REGION IN NORTHWEST
FLOW...WHICH WILL CONTINUE THE CHANCES OF PRECIPITATION INTO EARLY
NEXT WEEK WITH TEMPERATURES IN THE 80S.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 714 PM EDT TUE JUL 7 2015

MVFR CLOUDS WILL STILL LINGER AT KJXN FOR AN HR OR TWO...BUT
CLEARING SKIES WILL PUSH IN THIS EVENING. WE WILL NEED TO MONITOR
THE FOG POTENTIAL AS WE HAD SOME RAIN. THE ATMOSPHERE IS DRYING
OUT SO...THE RISK IS TOO LOW TO ADD IT TO THE FORECAST AT THIS
TIME. WILL MONITOR TRENDS CLOSELY THROUGH THE EVENING.

WINDS WILL DIMINISH THROUGH THE EVENING AS THE PRESSURE GRADIENT
WEAKENS.


&&

.MARINE...
ISSUED AT 1003 PM EDT TUE JUL 7 2015

THE WINDS AND WAVES HAVE DIMINISHED SLIGHTLY SOONER THAN EXPECTED.
AS A RESULT I CANCELLED THE NORTHERN ADVISORIES AND WARNINGS
EARLY. STILL SOME 7 FOOT WAVES SOUTH OF HOLLAND BASED ON RECENT
DATA...SO THE HEADLINE WILL CONTINUE THERE.

&&

.HYDROLOGY...
ISSUED AT 1137 AM EDT TUE JUL 7 2015

LOCALLY HEAVY RAIN FELL IN THE PAST 12 HOURS OR SO AROUND AND
NORTH OF MUSKEGON. FURTHER SOUTHEAST ACROSS SOUTHWEST LOWER
MICHIGAN...HIGHER RAINFALL TOTALS WERE A BIT MORE SCATTERED. THIS
HAS RESULTED IN MINOR UPWARD TRENDS ON AREA RIVERS AND STREAMS.
THERE ARE NO IMMEDIATE CONCERNS FOR RIVER FLOODING. HOWEVER...THIS
MAY BECOME A CONCERN HEADING INTO NEXT WEEKEND.

DRY CONDITIONS ARE EXPECTED FOR THE NEXT 24 TO 36 HOURS BEFORE
ANOTHER ROUND OF PRECIPITATION REACHES THE SOUTHERN THIRD OF THE
FORECAST AREAS...MAINLY ALONG AND SOUTH OF I-94. SOME OF THE RAIN
MAY MAKE UP TO I-96 BUT IS EXPECTED TO BE LIGHTER ON THE TOTALS
ALONG THE NORTHERN FRINGES OF THE PRECIPITATION FIELD.

THE FRIDAY THROUGH SUNDAY TIMEFRAME IS STILL THE MAIN FOCUS WITH A
BOUNDARY THAT DRIFTS NORTHWARD LATE IN THE WEEK. PENDING BOUNDARY
PLACEMENT...ROUNDS OF SHOWERS AND THUNDERSTORMS COULD ADD UP TO
GENERAL TOTALS OF 1-2 INCHES. LOCALLY HIGHER AMOUNTS ARE CERTAINLY
POSSIBLE WITH THE GREATEST THREAT FOR HEAVY RAINFALL EXISTING
ACROSS THE SOUTHERN HALF OF THE CWA...ALONG I-96 AND SOUTH. GIVEN
RECENT RAINFALL AND PENDING WEDNESDAY NIGHT INTO THURSDAYS
ROUND...WEEKEND RAINFALL COULD ACT MORE AS RUNOFF AND LEAD TO
QUICKER RESPONSES ON RIVERS. RIVER FLOODING MAY BE SOMETHING WE
NEED TO MONITOR THROUGH THE WEEKEND.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...BEACH HAZARDS STATEMENT UNTIL 5 AM EDT WEDNESDAY FOR MIZ056-064-
     071.

LM...SMALL CRAFT ADVISORY UNTIL 5 AM EDT WEDNESDAY FOR LMZ844>846.

&&

$$

SYNOPSIS...DUKE
SHORT TERM...DUKE
LONG TERM...MWS
AVIATION...MJS
HYDROLOGY...JAM
MARINE...MJS



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