000
FXUS63 KGRR 181740
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
140 PM EDT TUE JUN 18 2013

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 330 AM EDT TUE JUN 18 2013

HIGH PRESSURE WILL BUILD DOWN FROM THE NORTH TODAY AND THEN REMAIN
IN CONTROL OF THE WEATHER PATTERN THROUGH MID TO LATE WEEK BRINGING
FAIR AND DRY WEATHER. HIGHS WILL BE COOLER TODAY AND WEDNESDAY
BEHIND THE FRONT ONLY REACHING THE 70 TO 75 DEGREE RANGE.
TEMPERATURES WILL MODERATE LATE IN THE WEEK THROUGH THE WEEKEND
REACHING THE 80S BY FRIDAY.

&&

.SHORT TERM...(TODAY THROUGH THURSDAY AFTERNOON)
ISSUED AT 330 AM EDT TUE JUN 18 2013

CANADIAN HIGH PRESSURE WILL BUILD DOWN FROM THE NORTH TODAY BRINGING
FAIR BUT SEASONABLY COOL WX WITH HIGH TEMPS ONLY REACHING 70 TO 75
DEGREES WITH NNE FLOW COOL AIR ADVECTION TODAY. ANY FAIR WX CU
SHOULD DISSIPATE BY LATE AFTN/EARLY EVE WITH MOSTLY CLEAR SKIES TO
FOLLOW FOR TONIGHT.

THE HIGH PRESSURE RIDGE WILL REMAIN IN CONTROL OF THE WX PATTERN
WEDNESDAY THROUGH THURSDAY WITH TEMPS STILL SEASONABLY COOL
WEDNESDAY BEFORE MODERATING ON THURSDAY AS SOUTH TO SOUTHWEST FLOW
WAA DEVELOPS.

.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 330 AM EDT TUE JUN 18 2013

MODEL AGREEMENT BETWEEN THE 00Z RUNS OF THE ECMWF AND GFS IS FAIRLY
GOOD THROUGH THE EXTENDED. WARM FRONT SLOWLY MOVES THROUGH OVER THE
WEEKEND WITH FLAT UPPER RIDGING BRINGING WARMER TEMPS BY SATURDAY
AND SUNDAY. THE FORECAST PROBLEM IS HOW EXTENSIVE THE CONVECTION
WILL BE ALONG THE FRONT AND HOW FAR NORTH IT SETS UP. THIS COULD BE
COMPLICATED BY MCS ACTIVITY AND RESULTING OUTFLOW BOUNDARIES.

WILL CARRY SLIGHT OR CHANCE POPS OVER THE WEEKEND AND INTO MONDAY
SHADED LOWER FURTHER SOUTH WHERE CAPPING EFFECT OF UPPER RIDGING
WILL BE MORE LIKELY TO LIMIT CONVECTION POTENTIAL.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 140 PM EDT TUE JUN 18 2013

DIURNAL CU WILL DISSIPATE WITH SUNSET LEAVING CLEAR SKIES
OVERNIGHT.

&&

.MARINE...
ISSUED AT 330 AM EDT TUE JUN 18 2013

NNE FLOW COOL AIR ADVECTION WILL PRODUCE WAVE HEIGHTS MAINLY IN THE
1 TO 3 FOOT RANGE TODAY WITH HIGHER WAVES FURTHER OFFSHORE. MINIMAL
WIND AND WAVE ACTION IS ANTICIPATED TONIGHT THROUGH MIDWEEK WITH
HIGH PRESSURE IN CONTROL.


&&

.HYDROLOGY...
ISSUED AT 330 AM EDT TUE JUN 18 2013

DRY WEATHER IS FORECAST TODAY THROUGH LATE WEEK SO NO SIGNIFICANT
HYDRO ISSUES ARE EXPECTED. HOWEVER TWO RIVER FLOOD ADVISORIES REMAIN
IN EFFECT FOR THE GRAND RIVER AT IONIA AND THE THORNAPPLE ABOVE
HASTINGS.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&

$$

SYNOPSIS...LAURENS
SHORT TERM...LAURENS
LONG TERM...OSTUNO
AVIATION...93
HYDROLOGY...LAURENS
MARINE...LAURENS