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000
FXUS63 KGRR 301917
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
317 PM EDT WED JUL 30 2014

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

.SYNOPSIS...
ISSUED AT 300 PM EDT WED JUL 30 2014

AN UPPER LEVEL LOW PRESSURE SYSTEM WILL REMAIN CENTERED OVER
ONTARIO THROUGH THE END OF THE WEEK. THIS SYSTEM WILL ACT TO KEEP
THE TEMPERATURES BELOW NORMAL FOR LOWER MICHIGAN. THERE WILL BE
A FEW SHOWERS AND THUNDERSTORMS AROUND...MAINLY DURING THE
AFTERNOON AND EVENING HOURS.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 300 PM EDT WED JUL 30 2014

THE MAIN CHALLENGE IN THE SHORT TERM DEALS WITH THE POTENTIAL FOR
SHOWERS AND THUNDERSTORMS. ENOUGH INSTABILITY DEVELOPED TO FORM A
FEW SHOWERS TODAY. MAY END UP WITH A FEW STORMS BASED OFF OF LOCAL
LAPS SOUNDINGS. COULD BE GUSTY WINDS GIVEN THE INVERTED V LOW
LEVEL PROFILE. THESE SHOULD DISSIPATE AS WE GO THROUGH THE
EVENING. THE MAIN AREA WILL GENERALLY BE SOUTHEAST OF A ALMA TO
GRAND RAPIDS LINE.

MODELS ARE TRYING TO DEVELOP A WAVE OF LOW PRESSURE THU NIGHT INTO
FRI ACROSS THE REGION. THE MID LEVEL TROUGH SHARPENS UP OVERHEAD
AND SATURATION DEEPENS CLOSE TO THE DGZ. THUS I BUMPED UP POPS TO
ACCOUNT FOR THIS POTENTIAL SYSTEM.

I DID ADD FOG TO THE AREA SOUTH OF HOLLAND THIS EVENING GIVEN THE
VISIBLE SATELLITE IMAGERY SHOWING THE MARINE FOG MOVING ONSHORE.





.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 300 PM EDT WED JUL 30 2014

THERE IS STILL A CHANCE OF DIURNALLY DRIVEN SHOWERS AND PERHAPS A
FEW STORMS SATURDAY WITH THE UPPER TROUGH AXIS AND ASSOCIATED POOL
OF COOLER AIR ALOFT OVERHEAD. THE TROUGH AXIS SHOULD FINALLY MOVE
EAST OF OUR REGION SUNDAY. TEMPS THROUGH THE WEEKEND WILL AVERAGE
QUITE CLOSE TO NORMAL.

A COLD FRONT WILL DROP DOWN FROM THE NW ON MONDAY BRINGING A CHANCE
OF SHOWERS AND THUNDERSTORMS. THE BOUNDARY WILL THEN LIKELY SLOW
DOWN AND POTENTIALLY STALL OUT ACROSS THE LOWER GREAT LAKES REGION
TUESDAY AND BRING A CONTINUED CHANCE OF SHOWERS AND STORMS TO OUR
AREA.

IN FACT THE CHANCE OF SHOWERS AND STORMS REMAINS IN THE
FORECAST THROUGH THE MIDDLE OF NEXT WEEK WITH THAT FRONTAL BOUNDARY
OVER OUR REGION AND WITH LOW PRESSURE EXPECTED TO GRADUALLY APPROACH
FROM THE WEST LATE NEXT WEEK. TEMPS SHOULD CONTINUE TO AVERAGE
RATHER CLOSE TO NORMAL NEXT WEEK. THERE IS STILL A CHANCE OF
DIURNALLY DRIVEN SHOWERS AND PERHAPS A
FEW STORMS SATURDAY WITH THE UPPER TROUGH AXIS AND ASSOCIATED POOL
OF COOLER AIR ALOFT OVERHEAD. THE TROUGH AXIS SHOULD FINALLY MOVE
EAST OF OUR REGION SUNDAY. TEMPS THROUGH THE WEEKEND WILL AVERAGE
QUITE CLOSE TO NORMAL.



&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY)
ISSUED AT 1230 PM EDT WED JUL 30 2014

VFR CONDITIONS ARE ANTICIPATED AT ALL THE TERMINALS THROUGH 18Z
THURSDAY. MAINLY DRY CONDITIONS ARE ANTICIPATED THIS AFTERNOON BUT
ISOLATED SHOWERS MAY DEVELOP BY LATE AFTERNOON INTO EARLY EVENING IN
THE VICINITY OF OUR SOUTHERN AND EASTERNMOST TERMINALS (KAZO...
KBTL... KJXN AND KLAN).

THE POTENTIAL FOR AN ISOLATED STORM LATE THIS AFTERNOON INTO EARLY
EVENING IS QUITE LOW AND THERE IS NOT ENOUGH POTENTIAL FOR ONE TO
WARRANT INCLUSION IN ANY OF THE TERMINAL FORECASTS.

VFR CONDITIONS WILL CONTINUE THURSDAY MORNING AND EARLY AFTERNOON
WITH POTENTIAL FOR A FEW SHOWERS TO DEVELOP BY EARLY THURSDAY
AFTERNOON NEAR TO MAINLY EAST OF US-131.


&&

.MARINE...
ISSUED AT 300 PM EDT WED JUL 30 2014

THE DENSE FOG HAS SHIFTED SOUTH OF HOLLAND. BASED ON SATELLITE
LOOPS IT LOOKS LIKE IT WILL PERSIST FOR A FEW MORE HOURS. SO I
EXPANDED THE HEADLINE SOUTH AND EXTENDED IT TO 00Z. I CANCELLED IT
FURTHER NORTH.

&&

.HYDROLOGY...
ISSUED AT 300 PM EDT WED JUL 30 2014

NO MAJOR HYDROLOGY ISSUES EXPECTED. THE PRECIPITATION IS FORECASTED
TO BE SCATTERED.  AS A RESULT NOT MUCH BASIN AVERAGE RAINFALL
PREDICTED. WILL NEED TO MONITOR THE POSSIBLE WAVE FOR THU NIGHT
INTO FRI. TRENDS COULD SUPPORT A STEADIER RAIN EVENT.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...DENSE FOG ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LMZ844>846.

&&

$$

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