National Weather Service Weather Forecast Office

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

000
FXUS63 KGRR 240005
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
805 PM EDT THU MAY 23 2013

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 333 PM EDT THU MAY 23 2013

THE RAIN WILL END IN ALL AREAS THIS EVENING...WITH COOL HIGH
PRESSURE BUILDING INTO THE GREAT LAKES REGION TONIGHT. THE HIGH WILL
REMAIN SITUATED OVER THE GREAT LAKES INTO SUNDAY PROVIDING MAINLY
CLEAR AND COOL CONDITIONS. AREAS OF FROST ARE EXPECTED ALONG AND
NORTH OF INTERSTATE 96 TONIGHT AND ACROSS CENTRAL LOWER MICHIGAN
FRIDAY AND SATURDAY NIGHTS. HIGHS WILL TOP OUT IN THE 60S
FRIDAY...SATURDAY AND SUNDAY. READINGS WILL FINALLY PUSH BACK TO
AROUND 70 ON MEMORIAL DAY. THE NEXT SUBSTANTIAL CHANCE FOR RAIN WILL
COME AFTER THE MEMORIAL DAY WEEKEND INTO THE MIDDLE OF NEXT WEEK.

&&

.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 333 PM EDT THU MAY 23 2013

LIMITED CONCERNS IN THE SHORT TERM...WITH THE MAIN CONCERN BEING
FROST. HAVE DECIDED TO EXPAND THE FROST ADVISORY TO THE SOUTH GIVEN
TEMPS THAT WILL SLIP INTO THE MIDDLE 30S AS FAR SOUTH AS THE
INTERSTATE 96 CORRIDOR. WINDS ARE A CONCERN WITH A FAIRLY
SUBSTANTIAL WIND HANGING IN MOST OF THE NIGHT BETWEEN 1000 AND
2000FT. EVEN AT THE SURFACE SOME WIND WILL CONTINUE. THE STICKING
POINTS THOUGH ARE THE VERY DRY DEW POINTS THAT ARE BEING ADVECTED
SOUTH BY BOTH THE NAM AND THE HIRES ARW. THOSE DEW POINTS COMBINED
WITH A FEW HOURS CENTERED AROUND 09Z WHEN THE WINDS WILL TRY TO TAIL
OFF SOME COULD LEAD TO AREAS OF FROST IN LOW LYING AREAS. SO...FROST
ADVISORY TONIGHT FROM OTTAWA...KENT...IONIA AND CLINTON COUNTIES
NORTHWARD.

OTHERWISE...CLEAR TO PARTLY CLOUDY CONDITIONS WITH AREAS OF FROST
FRIDAY AND SATURDAY NIGHTS ACROSS CENTRAL LOWER MICHIGAN. THE RAIN
SHOULD BE EXITING THE FAR SOUTHEAST CWA AROUND 00Z.

.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 333 PM EDT THU MAY 23 2013

THE MAIN CHALLENGE IN THE LONG TERM DEALS WITH THE TIMING OF ANY
RAINFALL.  BASICALLY I BROUGHT IN SOME SHOWERS SOONER...STARTING
MONDAY NIGHT.

NOT VERY GOOD AGREEMENT AMONGST THE LONG RANGE MODELS...SO
CONFIDENCE IS LOWER THAN AVERAGE. TREND IS FOR A MORE AMPLIFIED MID
LEVEL FLOW SHOWING THE UPPER LOW PARKED OVER NEW ENGLAND FOR ANOTHER
DAY.  MOST RECENT GFS AND NAM 12Z...SHOWS WARM AIR ADVECTION AND
ELEVATED INSTABILITY MOVING IN LATER MONDAY INTO MONDAY NIGHT.  THE
INSTABILITY IS VERY ELEVATED...UP AROUND 700 MB.  COULD BE SOME
SHOWERS AND THUNDERSTORMS MOVING IN FROM THE SOUTHWEST LATER MONDAY
BASED ON THIS.  THE 00Z HIGH RES EURO KEEPS IT DRY THROUGH
TUE...ALTHOUGH THE 12Z LOW RES ECMWF SEEMS TO SHOW THE SURFACE WARM
FRONT JUST SOUTH OF THE MI BORDER 12Z TUE.  THAT WOULD WARRANT
ELEVATED PRECIPITATION BY THEN.  SO WILL BRING THE PRECIPITATION IN
SLIGHTLY SOONER THAN EARLIER FORECASTED

TEMPERATURES WILL WARM UP THROUGH THE PERIOD AS THE WARM AIR
ADVECTION TAKES CONTROL.  THE WARMEST DAYS SHOULD BE WED OR THU
GIVEN THE 850 MB THERMAL RIDGE MOVING IN.  I BUMPED UP TEMPERATURES
A DEGREE OR TWO OVER GUIDANCE GIVEN THE 850 MB TEMPS INTO THE TEENS.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 804 PM EDT THU MAY 23 2013

MVFR TO IFR CIGS WERE STILL HANGING ON SOUTH AND EAST OF GRR EARLY
THIS EVENING WHILE VFR CONDITIONS WITH CLR-SCT CONDITIONS WERE
PRESENT NORTH AND WEST OF GRR. AS DRY AIR CONTINUES SPREADING DOWN
FROM THE NORTH TONIGHT... VFR CONDITIONS SHOULD ALSO DEVELOP
SOUTH AND EAST OF GRR BY 03Z. HOWEVER THE TIMING OF THE CLEARING
IS ONLY LOW TO MEDIUM CONFIDENCE AND COULD BE DELAYED SEVERAL
HOURS AT LAN AND JXN. GUSTY NORTH WINDS WILL DIMINISH TO 10 KNOTS
OR LESS THIS EVENING. VFR CONDITIONS ARE LIKELY FOR FRIDAY.


&&

.MARINE...
ISSUED AT 333 PM EDT THU MAY 23 2013

WILL LEAVE THE GALE WARNING IN PLACE INTO THE EVENING HOURS...AS 18Z
OBS SHOWED BIG SABLE GUSTING TO 35 KNOTS...THE SOUTHERN MID LAKE
BUOY 39 KNOTS AND THE MICHIGAN CITY LIGHT HOUSE GUSTING TO 45 KNOTS.
WINDS SHOULD BEGIN TO COME DOWN THROUGH THE COURSE OF THE EVENING
HOURS AT WHICH TIME WE CAN TRANSITION THE ENTIRE NEARSHORE AREA BACK
INTO A SMALL CRAFT ADVISORY. CONDITIONS SHOULD FALL BELOW SMALL
CRAFT ADVISORY CRITERIA SHORTLY AFTER DAYBREAK ON FRIDAY...WITH
QUIESCENT CONDITIONS EXPECTED INTO THE WEEKEND.


&&

.FIRE WEATHER...
ISSUED AT 333 PM EDT THU MAY 23 2013

RECENT RAINS HAVE PROVIDED A SOAKING...ESPECIALLY ACROSS CENTRAL
LOWER MICHIGAN. GREEN UP IS ALMOST COMPLETE...WITH THE EXCEPTION
BEING THE JACK PINE IN OUR FAR NORTH. NOT EXPECTING SIGNIFICANT FIRE
WEATHER ISSUES INTO THE HOLIDAY WEEKEND...BUT IT DOES NOT TAKE LONG
FOR FINE FUELS TO DRY OUT AGAIN. IN ADDITION...THE FAR SOUTH DID NOT
RECEIVE A LOT OF RAIN OUT OF THIS EVENT AND FIRE WEATHER INDICIES
THERE ARE HIGHER.

&&

.HYDROLOGY...
ISSUED AT 333 PM EDT THU MAY 23 2013

HEAVIEST RAINFALL IN OUR RECENT EVENT FELL ACROSS CENTRAL LOWER
MICHIGAN WITH LITTLE IN THE WAY OF AFFECTS SEEN FROM THE GRAND RIVER
BASIN SOUTH. 3 RIVER ADVISORIES HAVE BEEN ISSUED...MOUNT PLEASANT
...CROTON AND MORLEY. A ONE DAY TOTAL WAS RECEIVED THIS MORNING FROM
NEAR MONTAGUE OF 2.51 INCHES.

DRY WEATHER IS FORECAST INTO THE UPCOMING HOLIDAY WEEKEND...SO
EXPECT RIVER LEVELS TO BEGIN TO SLOWLY FALL WITHIN A FEW DAYS.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...FROST ADVISORY FROM 1 AM TO 7 AM EDT FRIDAY FOR MIZ037>040-
     043>046-050>052-056>059.

LM...GALE WARNING UNTIL 11 PM EDT THIS EVENING FOR LMZ844>849.

&&

$$

SYNOPSIS...DUKE
SHORT TERM...DUKE
LONG TERM...MJS
AVIATION...MEADE
FIRE WEATHER...DUKE
HYDROLOGY...DUKE
MARINE...DUKE