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000
FXUS63 KGRR 132332
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
732 PM EDT THU JUN 13 2013

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 223 PM EDT THU JUN 13 2013

AN AREA OF HIGH PRESSURE IN THE UPPER PLAINS WILL BUILD SLOWLY
EAST THROUGH FRIDAY. THIS FAIR WEATHER SYSTEM WILL DRAW A DRIER
AND COOLER AIRMASS INTO MICHIGAN THAT WILL PERSIST INTO SATURDAY.
A WARM FRONT WILL LIFT INTO THE REGION SUNDAY. THIS SYSTEM COULD
BRING WITH IT UNSETTLED WEATHER.

&&

.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 223 PM EDT THU JUN 13 2013

THE MAIN CHALLENGE IN THE SHORT TERM DEALS WITH THE CLOUD COVER
TONIGHT.

THE COOLER AIRMASS FILTERING DOWN FROM THE NORTH COULD
LEAD TO SOME CLOUDS AS THE MODELS SHOW MOISTURE GENERALLY BELOW
850 MB. OVERVIEWS FROM BUFKIT SHOW SUBSIDENCE. WINDS GENERALLY ARE
DIVERGENT IN THE LOW LEVELS. SO MY THOUGHTS ARE THAT THERE WILL BE
FEWER CLOUDS AND WHAT THE MODELS INDICATE. AS A RESULT I KEPT THE
SKIES MOSTLY CLEAR TO PARTLY CLOUDY. ASSUMING THE SKIES DO STAY
SCATTERED MOST LOCATIONS SHOULD UP BELOW NORMAL IN THE MID 40S TO
LOW 50S.

WITH RIDGING DOMINATING THE PATTER INTO SATURDAY MORNING...I DO NOT SEE
MUCH POTENTIAL FOR SHOWERS. SOME WEAK ELEVATED INSTABILITY SHOWS
UP BY 00Z SUN...AND PERSISTS THROUGH THE NIGHT. THE SUBSIDENCE IN
THE MID LEVELS WEAKENS AS THE FLOW FLATTENS OUT. DOWN LOW...WARM
AND MOIST AIR ADVECTION WILL BE UNDERWAY. THUS I MAINTAINED THE
RISK FOR SOME THUNDERSTORMS.

.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 223 PM EDT THU JUN 13 2013

MAIN FEATURE ON THE WEATHER MAP GOING INTO THE LONG TERM PERIODS
WILL BE A STACKED UPPER LOW THAT WILL BE NEAR THE LAKE WINNIPEG
REGION. THIS SYSTEM SHOULD MAKE SLOW PROGRESS TOWARD THE GREAT
LAKES INTO THE FIRST PART OF THE WEEK. INITIALLY THIS SYSTEM
APPEARS TO BE SOMEWHAT MOISTURE STAVED..BUT THEN IT PULLS IN
RICHER GULF MOISTURE INTO MONDAY. WILL CARRY POPS FOR
SUN/MON...BUT THIS DOES NOT LOOK LIKE ALL-DAY RAINS...JUST
SCATTERED SHOWERS AND STORMS. THE SYSTEM SHOULD PASS THROUGH THE
AREA MONDAY NIGHT...BUT WILL KEEP LOW POPS GOING INTO TUESDAY TO
ACCOUNT FOR A POSSIBLE SLOWER MOVEMENT. TUESDAY NIGHT THROUGH
THURSDAY LOOKS DRY WITH HIGH PRESSURE ARRIVING.

AS FOR TEMPS...WE SHOULD SEE COOLER AIR MOVE IN BEHIND THE SYSTEM BY
TUESDAY AND THIS SHOULD LINGER THROUGH THE MIDDLE OF NEXT WEEK.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 732 PM EDT THU JUN 13 2013

VFR CONDITIONS EXPECTED THROUGH FRIDAY. SOME SHOWERS WILL BE NEAR
JXN AND LAN EARLY THIS EVENING BUT SHOULD DISSIPATE AROUND SUNSET.
WINDS WILL BE NORTH AROUND 10 KNOTS THIS EVENING.

&&

.MARINE...
ISSUED AT 223 PM EDT THU JUN 13 2013

WAVES HAVE BEEN BUILDING THROUGH THE DAY ON LAKE MI...SO WILL KEEP
THE SCA AND BEACH HAZARDS GOING INTO TONIGHT. NORTHERLY WINDS NOW
GUSTING OVER 20 KNOTS AT TIMES. BY DAYBREAK...VALUES SHOULD BE
LOW ENOUGH TO WARRANT THE EXPIRATION OF THESE PRODUCTS.

LIGHTER WINDS WILL THEN PREVAIL THROUGH FRIDAY AS THE PRESSURE
GRADIENT WEAKENS.

&&

.HYDROLOGY...
ISSUED AT 223 PM EDT THU JUN 13 2013

RUNOFF FROM THE OVERNIGHT HEAVY RAIN CONTINUES TO WORK ITS WAY
INTO THE TRIBUTARIES. RAPID RISES ON HEADWATER FORECAST POINTS
OCCURRED AS 2 TO 5 INCHES OF RAIN HIT SOME LOCATIONS SUCH AS
LANSING. THESE SPIKES IN THE RIVER LEVELS HAVE DIMINISH SOMEWHAT.
NO FLOODING IS FORECASTED...JUST SOME LOCATIONS RISING TO ACTION
STAGE. NO SIGNIFICANT QPF EXPECTED INTO SATURDAY.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...BEACH HAZARDS STATEMENT THROUGH FRIDAY MORNING FOR MIZ037-043-
     050-056-064-071.

LM...SMALL CRAFT ADVISORY UNTIL 8 AM EDT FRIDAY FOR LMZ844>849.

&&

$$

SYNOPSIS...MJS
SHORT TERM...MJS
LONG TERM...JK
AVIATION...OSTUNO
HYDROLOGY...MJS
MARINE...MJS