Area Forecast Discussion
Issued by NWS Grand Rapids, MI

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS63 KGRR 231625
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1225 PM EDT SAT MAY 23 2015

LATEST UPDATE...
HYDRO

.SYNOPSIS...
ISSUED AT 323 AM EDT SAT MAY 23 2015

HIGH PRESSURE WILL PROVIDE ONE MORE DAY OF FAIR WEATHER BEFORE
RAIN MOVES IN ON SUNDAY. THERE WILL BE CHANCE OF RAIN MOST DAYS
NEXT WEEK.

&&

.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 323 AM EDT SAT MAY 23 2015

SFC HIGH MOVES EAST TODAY AND RETURN FLOW SETS UP WITH ISENTROPIC
ASCENT DEVELOPING NORTH OF THE SFC WARM FRONT TONIGHT...BUT
PRECIP SHOULD HOLD OFF UNTIL SUNDAY MORNING WHEN STRENGTHENING
MID LEVEL WAA AND MOISTURE RETURN RESULT IN WARM ADVECTION WING OF
SHOWERS TO DEVELOP. THE MODELS HAVE BEEN CONSISTENT IN SHOWING
THIS THE PAST SEVERAL DAYS SO THERE IS FAIRLY HIGH CONFIDENCE THAT
THE RAINS WILL ARRIVE SUNDAY AFTERNOON INTO SUNDAY NIGHT ACROSS
THE CENTRAL AND NORTHERN FORECAST AREA. POTENTIAL FOR THUNDER
STILL LOOKS LIMITED BY LACK OF INSTABILITY.

MOIST SOUTHERLY FLOW SETS UP ON MONDAY WITH SOME WEAK UPPER LEVEL
DIVERGENCE...BUT NOTHING TO REALLY FOCUS THE PRECIP AFTER THE WARM
FRONT PUSHES NORTH OF THE AREA MONDAY MORNING. KEPT LIKELY POPS
GOING BUT IT IS POSSIBLE THE AFTERNOON MAY SEE A DECREASE IN THE
CHANCES FOR RAIN.

.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 323 AM EDT SAT MAY 23 2015

NEXT WEEK LOOKS INCREASINGLY MUGGY. THE BERMUDA HIGH WILL REMAIN
ANCHORED OVER THE WESTERN ATLANTIC THROUGH THE PERIOD. FLOW AROUND
THE HIGH WILL BE STRAIGHT OFF THE GULF AND ADVECT ABUNDANT MOISTURE
NORTHWARD TO THE GREAT LAKES. SFC DEWPOINTS WILL RISE INTO THE MID
60S BY THE END OF THE PERIOD. SEVERAL OPPORTUNITIES FOR SHOWERS AND
THUNDERSTORMS WILL EXIST...ALTHOUGH IT WON/T BE RAINING THE ENTIRE
TIME.

THE BEST CHANCE OF RAIN WILL COME TUESDAY NIGHT AND EARLY WEDNESDAY
AS A SFC LOW AND UPPER SHORT WAVE MOVE OVER THE CWA. FOLLOWING THE
PASSAGE OF THE TRAILING COLD FRONT... WE/LL LIKELY DRY OUT A BIT.
HOWEVER...THAT COLD FRONT WILL BECOME QUASI STATIONARY OVER THE CWA
AND ACT AS A FOCUS FOR MORE PCPN LATER IN THE PERIOD. EXACT
PLACEMENT OF THE FRONTAL BOUNDARY AND TIMING OF ANY ADDITIONAL SHORT
WAVES MAKES PINNING DOWN PCPN TIME FRAMES VERY DIFFICULT.

HIGHS WILL BE MAINLY IN THE 75 TO 80 RANGE THROUGH THE PERIOD.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 720 AM EDT SAT MAY 23 2015

VFR CONDITIONS WILL CONTINUE THROUGH TONIGHT. WINDS WILL BE
SOUTHWEST AOB 10 KNOTS.


&&

.MARINE...
ISSUED AT 323 AM EDT SAT MAY 23 2015

WINDS AND WAVES WILL BE FAIRLY LIGHT TODAY AND SUNDAY BEFORE
INCREASING SUNDAY NIGHT INTO MONDAY. FOG WILL INCREASE AS WARM
AND HUMID AIR MOVES OVER THE COLD LAKE WATERS ON SUNDAY NIGHT AND
MONDAY.


&&

.FIRE WEATHER...
ISSUED AT 1110 AM EDT SAT MAY 23 2015

WE WILL HAVE AN ELEVATED FIRE DANGER THROUGH THE AFTERNOON. RH
VALUES WILL HOVER AROUND 25 PERCENT IN THE DRY AIR MASS, WITH
TEMPS REACHING THE LOW AND MID 70S. HOWEVER WINDS ARE EXPECTED TO
STAY MOSTLY IN CHECK...PERHAPS BRIEFLY GUSTING TO AROUND 20 MPH.
HIGHER DEW POINTS WILL BE ADVECTING IN BY EARLY THIS EVENING
REDUCING THE RISK.

&&

.HYDROLOGY...
ISSUED AT 1225 PM EDT SAT MAY 23 2015

A VERY DRY AIRMASS IS IN PLACE OVER LOWER MI THIS AFTERNOON WITH
RH VALUES IN THE 20S. THAT WILL BEGIN TO CHANGE THIS EVENING INTO
TOMORROW AS MOISTURE IS ADVECTED INTO THE REGION. MULTIPLE ROUNDS
OF SHOWERS AND POSSIBLY SOME STORMS WILL BE POSSIBLE SUNDAY
AFTERNOON THROUGH THE COMING WEEK. RAIN WILL BE POSSIBLE EACH
DAY...WITH HIGHER CHANCES IN PARTICULAR SUNDAY AFTERNOON THROUGH
MONDAY MORNING AND ALSO TUESDAY AFTERNOON AND EVENING. TIMING
POTENTIAL PRECIP FROM MIDWEEK ON REMAINS DIFFICULT AT BEST.

OVERALL...WIDESPREAD RAINFALL OF 0.75 TO 2.00 INCHES IS POSSIBLE
THROUGH THURSDAY MORNING...WITH THE HIGHEST AMOUNTS FURTHER NORTH
OVER THE MUSKEGON AND PERE MARQUETTE BASINS. LESSER RAINFALL IS
EXPECTED OVER THE KALAMAZOO BASIN. RIVER LEVEL RISES ARE
EXPECTED...BUT FLOODING REMAINS UNCERTAIN. WIDESPREAD SIGNIFICANT
FLOODING APPEARS UNLIKELY DUE TO RECENT DRY WEATHER AND DECLINING
RIVER LEVELS...BUT LOCALIZED HEAVY RAINFALL AND FLOODING ARE POSSIBLE
FROM STRONGER THUNDERSTORMS.

&&

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

$$

SYNOPSIS...OSTUNO
SHORT TERM...OSTUNO
LONG TERM...04
AVIATION...OSTUNO
FIRE WEATHER...JK
HYDROLOGY...EBW
MARINE...OSTUNO


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.