National Weather Service National Headquarters

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

000
FXUS63 KGRR 230727
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
327 AM EDT THU MAY 23 2013

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

.SYNOPSIS...
ISSUED AT 327 AM EDT THU MAY 23 2013

SHOWERS WILL LINGER THROUGH THE MORNING HOURS...BUT THEN AS DRIER
AIR MOVES IN FROM THE NORTHWEST THE RAINS WILL COME TO AN END
THROUGH THE AFTERNOON AND EARLY EVENING FROM NORTHWEST TO
SOUTHEAST.  AFTER A GLOOMY START TO THE DAY MOST AREAS WILL SEE
SOME SUNSHINE BY LATE AFTERNOON OR EARLY EVENING.  THIS CLEARING
WILL BE THE START OF QUIET PERIOD OF WEATHER WHICH SHOULD LAST
THROUGHOUT THE HOLIDAY WEEKEND.

IT WILL BE MUCH COOLER TODAY WITH HIGHS ONLY 55 TO 60.  PATCHY FROST
WILL BE SEEN TONIGHT NORTH OF I-96.  HOWEVER TEMPERATURES WILL
GRADUALLY REBOUND INTO THE 60S FOR FRIDAY AND SATURDAY...AND MAINLY
INTO THE 70S FOR SUNDAY THROUGH WEDNESDAY.  THE NEXT CHANCE OF RAIN
SHOULD HOLD OFF UNTIL TUESDAY AND TUESDAY NIGHT.

&&

.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 327 AM EDT THU MAY 23 2013

A COLD FRONT CUT ACROSS THE CWA THIS MORNING AND IT WILL CONTINUE TO
SAG TO THE SOUTH TODAY.  FGEN BEHIND THE FRONT WAS SUPPORTING A BAND
OF SHOWERS OVER EASTERN WI/LK MI EARLY THIS.  THIS RAIN WILL SWING
THROUGH THE CWA FROM NW TO SE THROUGH THE COURSE OF THE DAY.  UPPER
DYNAMICS WERE ALSO HELPING THIS AREA OF RAIN...AND THE RIGHT
ENTRANCE
REGION OF THE JET WILL SLIDE OVER THE CWA WITH THE RAIN.  SO
NEEDLESS TO SAY THE BAND OF RAIN SHOULD HOLD TOGETHER AND IT LOOKS
WET THROUGH THE MORNING.  THEN THE BACK EDGE OF THE RAIN WILL
GRADUALLY SAG SE THROUGH THE CWA THROUGH THE AFTERNOON AND EARLY
EVENING.  MUCH DRIER AIR MOVES IN AND SKIES WILL CLEAR LATE TODAY.
THIS SHOULD GIVE MOST AREAS A LATE AFTERNOON/EARLY EVENING HIGH TEMP
AS A BIT OF SUNSHINE BOOSTS THE TEMPS UP A BIT.

WILL GO AHEAD WITH A FROST ADVISORY ACROSS THE NORTHERN CWA
TONIGHT.  THIS DOES NOT LOOK LIKE A PROLONG EVENT WITH THE NIGHTS
BEING SO SHORT THIS TIME OF YEAR.  ALSO WITH THE WINDS LIKELY
STAYING UP THROUGH THE EVENING THE ACTUALLY TIME FROST WILL DEVELOP
SHOULD ONLY BE 3 TO 5 HOURS.  LOCALIZED AREAS MAY FALL TO BELOW
FREEZING IN THE NORMALLY COLD LOW SPOTS...BUT THIS SHOULD BE TOO
BRIEF AND TOO ISOLATED TO NEED TO CONSIDER A FREEZE WARNING.

HIGH PRESSURE AND QUIET WEATHER PREVAILS FOR FRIDAY AND SATURDAY.
FROST POTENTIAL APPEAR TO BE LOWER FOR FRIDAY NIGHT GIVEN THAT SOME
MID/HI CLOUDS SHOULD BE MOVING IN ON THE HEELS OF WARM ADVECTION
ALOFT.  WILL MENTION PATCHY FROST FOR NOW AND WILL NEED TO MONITOR
CLOUD TRENDS.  DAYTIME TEMPS WARMING SLIGHTLY EACH DAY.

.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 327 AM EDT THU MAY 23 2013

A CLASSIC HUDSON BAY HIGH WILL VISIT OUR AREA INTO MONDAY PROVIDING
LITTLE IN THE WAY OF CLOUD COVER AND SLIGHTLY BELOW NORMAL
TEMPERATURES THROUGH MEMORIAL DAY. THIS WILL BLOCK ANY ATTEMPTS OF
SOUTHERN STREAM SHORTWAVES FROM BRINGING ANY CLOUDS AND
PRECIPITATION INTO THE AREA.

BEYOND MEMORIAL DAY THE FORECAST GETS MORE UNCERTAIN. WHILE WE START
OUT WITH AN OMAGE BLOCK TYPE PATTERN (WHICH IS WHY IT SHOULD STAY
MOSTLY CLEAR INTO MEMORIAL DAY) OVER TIME A POWERFUL STORM CURRENTLY
NEAR JAPAN CROSSES THE NORTH PACIFIC GAINING SUPPORT FROM A SYSTEM
IN THE BERING SEA LATE IN THIS WEEKEND. THE SYSTEM REACHES THE WEST
COAST IN THE WEDNESDAY TIME FRAME. NOW THERE ALREADY A SYSTEM
STALLED ALONG THE WEST COAST. WHEN THE JAPAN SYSTEM GETS WEST OF THE
DATELINE... THAT WILL FORCE THE CURRENT SYSTEM INLAND AND THAT WILL
TRY TO FLATTEN THE LARGE RIDGE (1-2 STANDARD DEVIATIONS FROM NORMAL
ON THE 500 MB HEIGHTS) BY MIDWEEK. THAT THEN SETS US UP TO BE IN THE
LINE OF FIRE FOR SHORTWAVES TRAVELING EAST ON THE SOUTHERN STREAM
JET. SO JUST HOW THIS PLAYS OUT IS ANYONE GUESS... SINCE THE
PRIMARY PLAYER IN ALL OF THIS HAS TO CROSS THE PACIFIC OCEAN YET.

SO... ALL THAT BEING SO I HAVE TO ADMIT THERE WILL BE A CHANCE OF
SHOWERS AND THUNDERSTORMS FROM TUESDAY AFTERNOON ON. THUS IN
INCREASED THE POP TO AROUND 30 PCT FROM THEN ON THROUGH THE REST OF
THE FORECAST. WHAT THIS MEANS IS THE FRONT STALLS NEAR US.  ANOTHER
ASPECT TO THIS IS IT SHOULD GET WARM TO HOT AS THE UPPER RIDGE IS
PUSHED EAST A TOUCH MID TO LATE WEEK.  I COULD SEE HIGHS WELL UP
INTO THE 80S FROM WEDNESDAY ON. AGAIN... TIMING SHORTWAVES AND SUCH
WILL BE AN ISSUE WITH THE TEMPERATURES... BUT BOTTOM LINE SUMMER
LIKE WEATHER RETURNS BY WEDNESDAY CONTINUES WELL BEYOND WEDNESDAY.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1215 AM EDT THU MAY 23 2013

ALTHOUGH HIGH CONFIDENCE STILL EXISTS THAT WIDESPREAD IFR/LIFR
CONDITIONS WILL EXPAND SOUTH AND EAST TONIGHT...IT MAY TAKE A FEW
MORE HOURS THAN EARLIER EXPECTED.

MKG AND GRR WERE ALREADY IFR/LIFR AS OF 04Z AND MOST OTHER
LOCATIONS SHOULD BECOME IFR/LIFR BY 08Z. WIDESPREAD RAIN AND
DRIZZLE ARE ALSO EXPECTED TO REDEVELOP LATER TONIGHT. THE TSTM
THREAT HAS DECREASED SUBSTANTIALLY SO DID NOT INCLUDE ANY CB/S IN
THE TAFS TONIGHT.

IMPROVEMENT IN FLIGHT CONDITIONS WILL TAKE PLACE THURSDAY
AFTERNOON FROM NORTH TO SOUTH. RAIN WILL END AND CIGS SHOULD RISE
INTO MVFR CATEGORY AFTER 18Z... WITH SFC WINDS INCREASING FROM
THE NORTH TO 10 TO 20 KNOTS WITH SOME HIGHER GUSTS. WIDESPREAD VFR
IS EXPECTED THURSDAY NIGHT WITH DIMINISHING WINDS... HIGH
CONFIDENCE.

&&

.MARINE...
ISSUED AT 327 AM EDT THU MAY 23 2013

NORTH WINDS FLOWING DOWN THE LENGTH OF THE LAKE WILL PRODUCE
INCREASINGLY ROUGH CONDITIONS ON THE LAKE TODAY.  HIGHEST WAVES
EARLY THIS MORNING WILL BE NORTH OF WHITEHALL...BUT THESE ROUGHER
CONDITIONS WILL TRAVERSE SOUTH AND INCLUDE ALL OF THE NEARSHORE
AREAS BY LATE MORNING.  WAVES MAY BUILD AS HIGH AS 10 FEET OFF OF ST
JOSEPH BY THIS EVENING.  WINDS AND WAVES WILL SLOWLY DIMINISH
TONIGHT INTO EARLY FRIDAY AS HIGH PRESSURE MOVES IN.

&&

.FIRE WEATHER...
ISSUED AT 327 AM EDT THU MAY 23 2013

MORE RAIN TODAY WILL KEEP FIRE DANGER LOW.  MUCH DRIER AIR ARRIVES
FOR FRIDAY AND SATURDAY WITH DAYTIME RH VALUES LOWERING TO AROUND 35
PERCENT.  HOWEVER WINDS WILL REMAIN UNDER 10 MPH FOR MUCH OF FRIDAY
AND SATURDAY.

&&

.HYDROLOGY...
ISSUED AT 327 AM EDT THU MAY 23 2013

ADDITIONAL RAIN TODAY WILL BE PERSISTENT...BUT WILL BE ON THE LIGHT
SIDE.  GENERALLY LESS THAN A QUARTER OF INCH IS EXPECTED.  RIVER
LEVELS ARE HIGH WITH ONE ADVISORY VALID FOR THE MUSKEGON RIVER NEAR
CROTON.  RIVER LEVELS SHOULD BEGIN TO SLOWLY FALL LATE TODAY AS THE
BEGINNING OF A DRY SPELL MOVES IN.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...FROST ADVISORY FROM 1 AM TO 7 AM EDT FRIDAY FOR MIZ037>040-
     044>046.

LM...SMALL CRAFT ADVISORY UNTIL 4 AM EDT FRIDAY FOR LMZ847>849.

     SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO NOON EDT FRIDAY
     FOR LMZ844>846.

&&

$$

SYNOPSIS...JK
SHORT TERM...JK
LONG TERM...WDM
AVIATION...MEADE
FIRE WEATHER...JK
HYDROLOGY...JK
MARINE...JK