Area Forecast Discussion
Issued by NWS Grand Rapids, MI

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
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 011930
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
330 PM EDT MON SEP 1 2014

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

.SYNOPSIS...
ISSUED AT 301 PM EDT MON SEP 1 2014

SHOWERS AND A FEW GUSTY THUNDERSTORMS WILL MOVE EAST OF THE AREA
THIS EVENING AS A WEAK COLD FRONT PUSHES THROUGH THIS EVENING.
MAINLY FAIR...WARM...AND DRIER WEATHER RETURNS FOR TUESDAY AND
WEDNESDAY BEFORE MUGGY AIR RETURNS WITH A CHANCE OF THUNDERSTORMS
THURSDAY INTO FRIDAY.

&&

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 301 PM EDT MON SEP 1 2014

ISOLATED SEVERE WEATHER THREAT WILL CONTINUE ALONG AND EAST OF
U.S. ROUTE 127 THROUGH THE LATE AFTERNOON HOURS AS THE LEADING
EDGE OF DRIER AND SLIGHTLY COOLER AIR WORKS IN FROM THE WEST.
ALTHOUGH THE CONVECTION HAS REMAINED SOMEWHAT SHALLOW DUE TO A
LACK OF DEEPER UPPER DIVERGENCE...INSTANTANEOUS RAINFALL RATES
HAVE BEEN INMPRESSIVE WITH NEAR ZERO VISIBILITIES WITH THE LINE OF
SHOWERS.

STILL A FAIR AMOUNT OF INSTABILITY AHEAD OF THE LINE FOR KLAN DOWN
TOWARDS KJXN WITH CAPE OF ~1000 J/KG AND 0-6 KM BULK SHEAR OF
35-40 KTS...BUT THE DEEPER LIFT ASSOCIATED WITH UPPER
SHORTWAVE/LF EXIT REGION OF ASSOCIATED JETLET ARE MOVING NORTHEAST
ACROSS NORTHERN LOWER. SO WHILE THERE IS STILL A THREAT...IT
SHOULD REMAIN FAIRLY ISOLATED.

ALTHOUGH LOW LEVELS DRY OUT SOMEWHAT OVERNIGHT COULD NOT RULE OUT
A FEW ISOLATED SHOWERS ON TUESDAY MORNING AS THERE WILL BE A
COUPLE OF WEAK SHORTWAVES/UPPER DIVERGENCE MOVING THROUGH BETWEEN
12Z AND 18Z. OTHERWISE PRETTY FAIR AND SEASONABLE WEATHER THROUGH
WEDNESDAY.

.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 301 PM EDT MON SEP 1 2014

NEXT SYSTEM ALSO PASSES WELL NORTH OF THE REGION LATE THU INTO FRI
WITH MUGGY AIRMASS RETURNING LATE ON THU. COULD SEE SOME
SHOWERS/T-STORMS EARLY THU ASSOCIATED WITH WARM FRONT AND
LOW LEVEL JET. NEXT CHANCE WOULD THEN FOLLOW FRI MORNING WITH THE
TRAILING COLD FRONT.

OVERALL THIS SYSTEM IS LOOKING SSIMILAR TO THE PRESENT
ONE WITH AN ISOLATED SEVERE THREAT...THERE WILL BE ABUNDANT
MOISTURE...CAPE OF 1000J/KG+ AND MARGINALLY HIGH BULK SHEAR BUT
THE DEEPER LIFT WILL PASS NORTH OF US ONCE AGAIN.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 122 PM EDT MON SEP 1 2014

A LINE OF SHOWERS AND THUNDERSTORMS WILL CROSS LOWER MICHIGAN THIS
AFTERNOON. BRIEF PERIODS OF HEAVY RAINFALL IS POSSIBLE WITH VSBYS
FALLING TO IFR/MVFR CONDITIONS. THE ACTUAL COLD FRONT WON/T PASS
THROUGH UNTIL AFTER MIDNIGHT. AS A RESULT...WE KEPT MVFR CIGS IN
THE TAFS UNTIL AROUND MIDNIGHT.


&&

.MARINE...
ISSUED AT 301 PM EDT MON SEP 1 2014

HEADLINES WILL EXPIRE THIS EVENING.  WINDS HAVE SHIFTED ONSHORE AT
THIS TIME AND WILL BEGIN TO DIMINISH THIS EVENING. BOUYS CONTINUE
TO SHOW WAVES OF 3 TO 4 FT WITH OCCASIONAL 5 TO 6 FOOTERS. ALL
SHOULD SUBSIDE BELOW 3 FT BY LATE EVENING. WE`LL LIKELY SEE A
REPEAT OF WIND/WAVES WITH NEXT SYSTEM THU INTO FRI.

&&

.HYDROLOGY...
ISSUED AT 1237 PM EDT MON SEP 1 2014

RIVERS ARE RUNNING A LITTLE ABOVE NORMAL... BUT ARE STILL FAR BELOW
BANK FULL. PRECIPITATION THROUGH THIS EVENING IS EXPECTED TO TOTAL
AROUND A QUARTER OF AN INCH WITH ISOLATED LOCATIONS NORTHWEST OF
GRAND RAPIDS RECEIVING NEARLY AN INCH. THIS SHOULD LEAD TO SMALL
RISES ON AREA RIVERS WITH PEAK LEVELS BELOW BANK FULL BY MID WEEK.
ADDITIONAL PRECIPITATION IS POSSIBLE WEDNESDAY INTO FRIDAY NIGHT.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...BEACH HAZARDS STATEMENT UNTIL 10 PM EDT THIS EVENING FOR MIZ037-
     043-050-056-064-071.

LM...SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR LMZ844>849.

&&

$$

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






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