Area Forecast Discussion
Issued by NWS Grand Rapids, MI

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FXUS63 KGRR 020725
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
325 AM EDT SAT AUG 2 2014

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

.SYNOPSIS...
ISSUED AT 325 AM EDT SAT AUG 2 2014

A WEAK HIGH PRESSURE RIDGE WILL BRING FAIR WEATHER WITH SEASONABLE
TEMPERATURES THIS WEEKEND. HOWEVER A FEW AFTERNOON AND EVENING
SHOWERS ARE ANTICIPATED TODAY. DRY WEATHER IS FORECAST ACROSS OUR
AREA SUNDAY FOLLOWED BY A FEW SHOWERS AND THUNDERSTORMS FOR MONDAY
AS A COLD FRONT MOVES IN.

&&

.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 325 AM EDT SAT AUG 2 2014

PRIMARY SHORT TERM FCST CONCERNS INVOLVE DETERMINING POTENTIAL FOR
CONVECTION LATER TODAY AND AGAIN FOR MONDAY.

A FEW DIURNALLY DRIVEN SHOWERS AND STORMS WILL DEVELOP THIS
AFTERNOON AND EARLY EVENING BETWEEN AROUND 18Z AND 00Z AS
INSTABILITY INCREASES MAINLY NEAR TO EAST OF US-131. CONVECTION IS
NOT ANTICIPATED FURTHER WEST TO THE STABILIZING INFLUENCE OF LAKE
MI. STRONGEST STORMS MAY CONTAIN HEAVY RAIN AND SMALL HAIL.
OVERALL CONVECTION TODAY SHOULD NOT BE AS STRONG AS YESTERDAY DUE
TO WEAKER LIFT.

THE WEAK HIGH PRESSURE RIDGE WILL BRING DRY WX ACROSS OUR FCST
AREA FROM LATE TONIGHT THROUGH SUNDAY NIGHT. BEYOND THAT A WEAK
COLD FRONT WILL BRING POTENTIAL FOR SOME SHOWERS AND THUNDERSTORMS
ON MONDAY. TEMPS WILL AVERAGE VERY CLOSE TO OR EVEN SLIGHTLY ABOVE
NORMAL THROUGH THE SHORT TERM FCST PERIOD.

.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 325 AM EDT SAT AUG 2 2014

DROUGHT MAY BECOME A MAJOR ISSUE OVER TIME FOR SOUTHWEST LOWER
MICHIGAN. WE WILL NEED TO MONITOR THIS FOR SURE. THAT IS THE MOST
SIGNIFICANT ASPECT OF THIS DEVELOPING WEATHER PATTERN FOR THIS AREA.
LARGELY DRY WEATHER IS EXPECTED FOR MOST OF THE CWA THROUGH
NEXT WEEK. MOST AREA ALONG THE LAKE SHORE AND SOUTH OF INTERSTATE
94 ENDED JULY WITH PRECIPITATION DEFICITS OF 1 TO 2 INCHES. ONLY
AREAS NORTH OF INTERSTATE 94 AND EAST OF US-131 HAD ABOVE NORMAL
PRECIPITATION IN JULY. IT IS QUESTIONABLE TO WHAT EXTENT THE
RAINFALL MONDAY INTO TUESDAY CAN HAVE ANY SIGNIFICANT IMPACT ON
THAT.

FOR NEXT WEEK THE BEST CHANCE FOR CONVECTION WILL BE MONDAY NIGHT
INTO EARLY TUESDAY AS THE NEXT COLD FRONT COMES THROUGH. THE SET UP
FOR THIS IS NOT CLASSIC FOR WIDESPREAD HEAVY RAINFALL (NORTHWEST
FLOW SHORTWAVE DIVING INTO A DEEPENING EASTERN TROUGH). AFTER THAT I
WOULD EXPECT LARGELY DRY WEATHER TO PREVAIL INTO THE NEXT WEEKEND.
TEMPERATURES WILL BE CLOSER TO NORMAL THAN THEY WERE LAST WEEK. THIS
NEXT COLD FRONT WILL NOT BRING AS MUCH COLD AIR SOUTH. I KEPT LOW
CHANCE POPS WEDNESDAY THROUGH FRIDAY MORE FOR THE SAKE OF CONTINUITY
THAN FOR ANY OTHER REASON. I EXPECT FOR THE MOST PART WEDNESDAY
THROUGH FRIDAY WILL BE TOTALLY DRY ACROSS THE AREA.

ONCE AGAIN I WILL POINT TO OUR RECURVING OF TYPHOON HALONG TO
SUPPORT THE TREND OF THE ECMWF OF HAVING A DEEPER AND MORE
PERSISTENT EASTERN TROUGH MOST OF NEXT WEEK. THAT WOULD LIMIT OUR
SHOWER AND THUNDERSTORM ACTIVITY TO THE MONDAY NIGHT INTO EARLY
TUESDAY. BEYOND THAT THE NEXT SHORTWAVE THE GFS AND CANADIAN GEM USE
TO BRING SHOWERS TO THIS AREA THURSDAY/FRIDAY DIVES WELL SOUTH OF
THE AREA ON THE ECMWF AND THAT IS DUE TO THE DEEPER EASTERN TROUGH.
WHICH ONCE I AGAIN THINK WILL PREVAIL AS THE PATTERN WE WILL
ACTUALLY SEE.

SO LARGELY EXPECT NEAR NORMAL TEMPERATURES WITH DRY WEATHER DURING
THIS TIME PERIOD WITH JUST A CHANCE OF THUNDERSTORMS MONDAY NIGHT
INTO EARLY TUESDAY BUT MANY PLACES WILL LIKELY NO SEE MUCH
PRECIPITATION FROM THIS EVENT.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1158 PM EDT FRI AUG 1 2014

THE COMBINATION OF LIGHT WINDS AND CLEARING SKIES WITH DEW PTS
NEAR 60 WILL LEAD TO SOME FOG OVERNIGHT INTO EARLY SATURDAY
MORNING. VSBYS SHOULD BE MOSTLY 2-4 MILES 08Z-13Z BUT AREAS OF
LOWER VSBYS ARE CERTAINLY POSSIBLE ESPECIALLY WHERE HEAVY RAIN
OCCURRED ON FRIDAY. WILL FCST VSBYS FALLING BELOW ONE MILE AT LAN
WHERE OVER AN INCH OF RAIN FELL.

DIURNAL SHOWER/STORMS ARE ANTICIPATED AGAIN ON SATURDAY AFTER 18Z
UNTIL SUNSET. BEST CHANCE IS AT LAN AND JXN... WITH LESSER CHANCES
FARTHER WEST. DRY ALONG THE LAKESHORE INCLUDING MKG SO NO MENTION
OF VCTS THERE.


&&

.MARINE...
ISSUED AT 325 AM EDT SAT AUG 2 2014

MINIMAL WIND AND WAVE ACTION IS ANTICIPATED THROUGH THE WEEKEND
WITH WIND SPEEDS AOB 15 KTS THROUGH MONDAY AND WAVE HEIGHTS OF
LESS THAN TWO FEET. HOWEVER SOME PATCHY FOG IS ANTICIPATED TODAY.

&&

.HYDROLOGY...
ISSUED AT 115 PM EDT FRI AUG 1 2014

OTHER THAN A COUPLE OF AFTERNOON THUNDERSTORMS THE WEATHER WILL BE
MAINLY DRY. RUNOFF WILL BE LIMITED DUE THE LOCALIZED NATURE OF THE
STORMS. THE ONLY REAL POTENTIAL IMPACT WOULD BE ISOLATED URBAN
FLOODING IF A STORM HAPPENED TO STALL OVER A CITY.

&&

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

$$

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








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