Area Forecast Discussion
Issued by NWS Grand Rapids, MI

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000
FXUS63 KGRR 230219
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1019 PM EDT FRI MAY 22 2015

LATEST UPDATE...
UPDATE

.SYNOPSIS...
ISSUED AT 330 PM EDT FRI MAY 22 2015

THE HOLIDAY WEEKEND WILL START OUT NICE ON SATURDAY WITH SUNSHINE
AND COMFORTABLE TEMPERATURES.  HOWEVER RAIN IS EXPECTED TO ARRIVE ON
SUNDAY...MAINLY ACROSS CENTRAL LOWER.  BETTER CHANCES OF RAIN MOVE
INTO SOUTHERN LOWER BY SUNDAY NIGHT AND MONDAY.

THE WET PERIOD IS EXPECTED TO CONTINUE INTO MID WEEK...BEFORE DRYING
OUT FOR THE LATTER HALF OF THE WEEK.  TEMPERATURES WILL REMAIN
WARM...MAINLY IN THE UPPER 70S AND LOWER 80S.

&&

.UPDATE...
ISSUED AT 1019 PM EDT FRI MAY 22 2015

DID NOT MAKE ANY CHANGES TO THE GOING FORECAST. AM A LITTLE
CONCERNED ABOUT THE AMOUNT OF HIGH CLOUDS STREAMING IN FROM THE
SOUTHWEST. IT LOOKS SOMEWHAT DENSE ON SATELLITE. UPPER LEVEL WINDS
ARE FROM THE NORTHWEST THOUGH...SO THINKING SOME OF THE CLOUD
WILL BE PUSHED SOUTHEAST. GIVEN WE ARE ONLY AN HOUR AFTER SUNSET
WITH DRY AIR IN PLACE WILL LET THE FORECAST PLAY OUT AND GIVE IT A
CHANCE TO VERIFY. THE DRY AIR WILL ONLY NEED A FEW HOURS OF
CLEARING LATE TO ALLOW TEMPS TO DROP LIKE A ROCK. LIGHT WINDS AND
MOSTLY CLEAR SKIES IN THE NORTHEAST CWA SHOULD ALLOW TEMPS TO
REACH FORECAST VALUES UP THERE...WHICH IS WHERE WE HAVE THE
FREEZE WARNING OUT.

&&

.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 330 PM EDT FRI MAY 22 2015

WILL ISSUE A FROST ADVISORY FOR MOST AREAS ALONG AND NORTH OF I-
96...AND A FREEZE WARNING FOR THE FAR NE COUNTIES.  CLEAR SKIES AND
LIGHT WINDS WILL ALLOW TEMPS TO DIP INTO THE 30S...AND THERE MAY BE
A FEW 20S FAR NE.

QUIET WEATHER INTO SATURDAY EVENING...THEN THE RISK OF SHOWERS AND A
FEW STORMS ARRIVE LATE SATURDAY AND INTO SUNDAY.

HIGH PRESSURE REMAINS IN CONTROL.  WE WILL SEE TEMPS REBOUND INTO
THE LOW AND MID 70S FOR SAT AND SUN AS SOUTHERLY FLOW TAKES OVER
BEHIND THE HIGH.

ADDED A 20 POP TO AREAS NORTH OF I-96 SATURDAY NIGHT AS WE WILL SEE
MOISTURE ADVECTION INTO THE AREA AHEAD OF A WARM FRONT ADVANCING
NORTHWARD.  ALSO SEEING SOME ELEVATED INSTABILITY WHICH SUPPORTS
SOME ISOLATED THUNDER.

THE MAIN THRUST OF MOISTURE AND LIFT ASSOCIATED WITH THE WARM FRONT
MOVES INTO CENTRAL LOWER SUNDAY...AND SOUTHWEST LOWER LATE SUNDAY
NIGHT. THIS IS THE TIMING USED TO INCLUDE LIKELY POPS.  INSTABILITY
NEVER BECOMES STRONG AS THERE SHOULD BE A FAIR AMOUNT OF CLOUDS
AROUND.  SO NOT EXPECTING SEVERE STORMS DURING THIS PERIOD.


.LONG TERM...(MONDAY THROUGH FRIDAY)
ISSUED AT 330 PM EDT FRI MAY 22 2015

A MORE SUMMERLIKE PATTERN SHAPING UP FOR NEXT WEEK WITH ABOVE NORMAL
TEMPERATURES AND INCREASINGLY HUMID CONDITIONS. ALTHOUGH THE PATTERN
WILL FEATURE SOUTHWEST FLOW ALOFT WITH A CHANCE OF SHOWERS AND TSTMS
EACH DAY... THE WHOLE WEEK CERTAINLY WILL NOT BE A WASHOUT WITH
SEVERAL DRY PERIODS INBETWEEN THE SCATTERED CONVECTION.

AFTER THE WARM FRONT PUSHES NORTH THROUGH THE MONDAY... OFFERING A
HIGH CHANCE OF SHOWERS AND STORMS... WE STAY IN A WARM AND HUMID AIR
MASS MUCH OF NEXT WEEK WITH CONTINUED DAILY CHANCES OF SHOWERS AND
TSTMS. CONFIDENCE IS LOW HOWEVER ON THE DAILY COVERAGE AND TIMING OF
CONVECTION ESPECIALLY SINCE THE SFC FRONT LOOKS RATHER WEAK AND
ILL DEFINED.

THE GFS/ECMWF DO SEEM TO AGREE ON A DECENT LOOKING SHORTWAVE LIFTING
NORTHEAST INTO THE AREA FROM THE CENTRAL PLAINS ON WEDNESDAY.
PERHAPS THIS FEATURE WILL OFFER A MORE WIDESPREAD/HIGHER PROBABILITY
OF RAIN... IF THE CURRENT SOLUTION HOLDS.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 817 PM EDT FRI MAY 22 2015

VFR WEATHER IS EXPECTED THE NEXT 24 HOURS. WINDS WILL BECOME LIGHT
AND VARIABLE SHORTLY AFTER SUNSET AND CONTINUE THAT WAY THROUGH
ABOUT 14Z ON SATURDAY. SOUTHWEST WINDS AROUND 10 MPH ARE EXPECTED
ON SATURDAY. HIGH CLOUDS WITH BASES AT OR ABOVE 15000FT SHOULD BE
THE ONLY CLOUDS THROUGH SATURDAY AFTERNOON.


&&

.MARINE...
ISSUED AT 330 PM EDT FRI MAY 22 2015

WITH HIGH PRESSURE IN CONTROL WINDS AND WAVES REMAIN LOW TONIGHT.
SOUTHERLY WINDS TAKE OVER SATURDAY THROUGH SUNDAY NIGHT AND STAY
UNDER 20 KTS.


&&

.HYDROLOGY...
ISSUED AT 1226 PM EDT FRI MAY 22 2015

DRY WEATHER IS EXPECTED THROUGH SATURDAY NIGHT. RAIN IS EXPECTED
TO MOVE IN SUNDAY AFTERNOON AND BE MOST WIDESPREAD SUNDAY NIGHT.
THIS WILL BE THE START OF A WARMER AND WETTER PATTERN THAT WILL
PERSIST THROUGH NEXT WEEK. NATIONAL GUIDANCE ADVERTISES UNIFORM
RAINFALL TOTALS OF 0.5-1.5 INCHES ACROSS SOUTHWEST LOWER MICHIGAN
THROUGH THURSDAY NIGHT.

CONFIDENCE IN FLOODING REMAINS LOW AT THIS TIME. RISES ON AREA
RIVERS CAN CERTAINLY BE EXPECTED NEXT WEEK. THUNDERSTORMS HAVE
THE POTENTIAL TO PRODUCE HIGHER RAINFALL AMOUNTS IN A SHORT
PERIOD OF TIME. THE RISK FOR STRONGER STORMS AND HEAVY RAINFALL
WILL CONTINUE TO BE ASSESSED OVER THE HOLIDAY WEEKEND.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...FROST ADVISORY UNTIL 8 AM EDT SATURDAY FOR MIZ037-038-043>046-
     051-052-057>059-067.

     FREEZE WARNING UNTIL 8 AM EDT SATURDAY FOR MIZ039-040.

LM...NONE.
&&

$$

UPDATE...DUKE
SYNOPSIS...JK
SHORT TERM...JK
LONG TERM...MEADE
AVIATION...DUKE
HYDROLOGY...EBW
MARINE...JK



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