Area Forecast Discussion
Issued by NWS Grand Rapids, MI

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FXUS63 KGRR 031631
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1230 PM EDT SUN MAY 3 2015

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 337 AM EDT SUN MAY 3 2015

ONE MORE FINE DAY TODAY WITH PARTLY SUNNY SKIES AND TEMPERATURES
REACHING THE UPPER 70S INLAND FROM LAKE MICHIGAN.  THEN A COLD FRONT
APPROACHES TONIGHT AND WILL BRING SHOWERS AND THUNDERSTORMS.  MOST
OF THE PRECIPITATION WILL BE NORTH OF I-96 TONIGHT...THEN SPREAD
INTO SOUTHERN LOWER MICHIGAN ON MONDAY.  THE FRONT MOVES SOUTH INTO
NORTHERN INDIANA BY MONDAY NIGHT AND STALLS THERE.  THIS WILL CAUSE
THE SHOWERS A FEW STORMS TO LINGER MAINLY ALONG AND SOUTH OF I-96
MONDAY NIGHT AND TUESDAY.  MEANWHILE AREAS NORTH OF I-96 SHOULD ONLY
SEE SCATTERED SHOWERS INTO TUESDAY.  DAYTIME TEMPERATURES WILL COOL
SLIGHTLY TO THE UPPER 60S TO AROUND 70 FOR MONDAY AND TUESDAY.

IT APPEARS WE WILL DRY OUT TOWARD MID WEEK...WITH ANOTHER CHANCE OF
STORMS ARRIVING FRIDAY INTO SATURDAY.  DAYTIME HIGHS SHOULD RETURN
INTO THE 70S AND MAY APPROACH 80 THURSDAY AND FRIDAY.

&&

.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 337 AM EDT SUN MAY 3 2015

ANOTHER VERY NICE SPRING DAY TODAY...THEN RAIN CHANCES RETURN
TONIGHT AND LINGER INTO TUESDAY. SEVERE THREAT STILL LOOKS MINIMAL
AND EXCESSIVE RAIN CHANCES ALSO LOOK REMOTE.

INCREASED MAX TEMPS FORECAST AGAIN DUE TO VERY DRY AIR MASS AND
FAVORABLE MIXING.  FEEL UPPER 70S WILL BE COMMON AND AN ISOLATED 80
IS NOT OUT OF THE QUESTION.  WE SHOULD SEE A FEW SOME DEBRIS CLOUDS
ROLL IN BY MID AFTERNOON WHICH TAPER THE MIXING AND HEATING AFTER
18Z.

A COLD FRONT MOVING ACROSS MN THIS MORNING WILL REACH SOUTHWEST MI
ON MONDAY.  THE FRONT WILL HAVE FAVORABLE JET DYNAMICS TO OUR WEST
LATER THIS AFTERNOON AND EXPECT WIDESPREAD PCPN SPREADING ACROSS
WISCONSIN.  THE UPPER JET BRINGS IN WEAK UPPER DIVERGENCE INTO THE
NW CWA TONIGHT.  SO SOME OF THE WISCONSIN CONVECTION SHOULD HOLD
TOGETHER AND MOVE INTO CENTRAL LOWER TONIGHT.  EXPECTING OF THIS
ACTIVITY TO REMAIN NORTH OF I-96 AS AREAS SOUTH OF THERE WILL BE TOO
FAR REMOVED FROM THE UPPER JET.  SO GENERALLY WILL CARRY LIKELY POPS
NORTH AND CHC POPS SOUTH OF I-96.

THE SHOWERS AND STORMS GRADUALLY SHIFT SOUTH ON MONDAY AS THE FRONT
COMES THROUGH.  DECENT INSTABILITY COULD BE REALIZED SOUTH OF I-96
BY AFTERNOON WHERE WE MAY SEE AN ISOLATED STRONGER STORM...BUT THIS
WILL DEPEND ON THE EXTENT OF THE MORNING CLOUD COVER.  THE FORCING
DOES NOT LOOK STRONG ENOUGH TO BE TOO CONCERNED THOUGH...AS THE
FRONT BECOMES MORE PARALLEL TO THE UPPER FLOW.

THE FRONT MOVES THROUGH BY MONDAY EVENING AND STALLS OVER NORTHERN
INDIANA MONDAY NIGHT AND TUESDAY.  DECENT OVER RUNNING FORCING IS
SHOWN FOR AREAS SOUTH OF I-96...SO THE SHOWERS SHOULD CONTINUE WITH
A FEW EMBEDDED STORMS.

THE CONVECTIVE NATURE OF THE PCPN COULD LEAD LOCALIZED HEAVY
RAIN...BUT OVERALL EXPECT AROUND A QUARTER INCH FOR CENTRAL...AND UP
TO THREE QUARTER OF AN INCH FOR THE I-94 REGION THROUGH TUESDAY.

.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 337 AM EDT SUN MAY 3 2015

PRIMARY FOCUS IS ON THE CHANCE FOR SCATTERED SHOWERS/STORMS TUESDAY
NIGHT AND WEDNESDAY AND ALSO THE DEGREE OF WARMTH FOR THURSDAY AND
FRIDAY.

STATIONARY BOUNDARY ACROSS FAR SOUTHERN LOWER MI TUESDAY NIGHT
BEGINS LIFTING NORTH AS A WARM FRONT WITH UPPER LEVEL RIDGE
AMPLIFICATION OCCURRING ACROSS THE OHIO VALLEY AND GREAT LAKES
REGIONS. THIS FRONT WILL SERVE AS A SOURCE OF LIFT AND PROVIDE
OPPORTUNITY FOR SOME SCATTERED SHOWER/STORM DEVELOPMENT COINCIDENT
WITH RISING DEW POINTS INTO THE UPPER 50S/NEAR 60 ON WEDNESDAY.
MODEL QPF IS NOT OVERLY BULLISH ON WEDNESDAY...BUT WOULD EXPECT SOME
CONVECTIVE DEVELOPMENT AFTER MORNING H925 TEMP INVERSION IS MIXED
OUT AND SFC BASED CAPE OF A FEW HUNDRED JOULES/KG ARE REALIZED ALONG
WITH LI VALUES SLIGHTLY NEGATIVE. THAT SAID...WITH WINDS AT OR BELOW
20 KTS FROM THE LCL TO THE EL AND MARGINAL CAPE IN THE -10C TO -20C
LAYER...THERE IS NO REAL THREAT FOR SEVERE WEATHER.

BY THURSDAY...MOSTLY DRY CONDITIONS ARE EXPECTED WITH A FEW STRAY
SHOWERS OR STORMS POSSIBLE...BUT WITH A LACK OF ANY TRIGGER VERY
LITTLE CONVECTIVE ACTIVITY IS FORESEEN. H850 TEMPS OF 13C BY 00Z FRI
SUPPORT HIGHS AROUND 80. FOR FRIDAY...A SFC COLD FRONT SHOULD BE
PUSHING THROUGH WISCONSIN DURING THE AFTERNOON HOURS...AND WE MAY
HAVE A CHANCE TO MIX DOWN 14C AIR...WHICH WOULD SUPPORT HIGHS IN THE
LOWER 80S. GIVEN INCREASING CLOUD COVER AND POSSIBLE SHOWER/STORM
DEVELOPMENT AHEAD OF THIS FRONT...WE MAY NOT QUITE GET THERE BUT IT
IS STILL A DECENT POSSIBILITY. FOR NEXT WEEKEND...NEED TO CONTINUE
THE MENTION FOR SHOWER/STORM POSSIBILITIES AS UPPER LEVEL RIDGING
MAY RELAX SOMEWHAT BUT WITH CONTINUED MOIST LOW LEVEL FLOW AND
POSSIBLE SFC BOUNDARY IN PLAY ONCE AGAIN ACROSS THE GREAT LAKES.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY)
ISSUED AT 1230 PM EDT SUN MAY 3 2015

VFR CONDITIONS WILL CONTINUE THIS AFTERNOON BUT IT WILL BE BREEZY
WITH SW WIND GUSTS TO NEAR 25 KTS AND GRADUALLY INCREASING MID LEVEL
CLOUD COVER. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL
DEVELOP MAINLY AFTER MIDNIGHT. CONDITIONS WILL GRADUALLY DETERIORATE
TO MVFR VERY LATE TONIGHT THROUGH MIDDAY MONDAY.

BRIEF REDUCTIONS TO IFR CONDITIONS ARE POSSIBLE DURING THE EARLY
MORNING HOURS MONDAY THROUGH 18Z MONDAY IN HEAVIER SHOWERS AND
ISOLATED STORMS. PRIMARILY MVFR CONDITIONS WILL CONTINUE INTO MONDAY
AFTERNOON DUE TO EXTENSIVE LOW CLOUD COVER AND LINGERING SHOWERS AND
ISOLATED STORMS. THE BETTER CHANCE FOR THUNDERSTORMS MONDAY
AFTERNOON WILL BE SOUTH OF THE I-94 CORRIDOR ACROSS NORTHERN
INDIANA/OHIO.

&&

.MARINE...
ISSUED AT 337 AM EDT SUN MAY 3 2015

SOUTH WINDS WILL CAUSE WAVES TO INCREASE THIS AFTERNOON MAINLY NORTH
OF HOLLAND.  EXPECT SOME 3 FOOTERS...BUT OVERALL A SMALL CRAFT
ADVISORY IS NOT EXPECTED TO BE NEEDED.  THESE WAVES WILL DIMINISH
LATE TONIGHT/EARLY MONDAY AS THE FRONT MOVES IN.


&&

.FIRE WEATHER...
ISSUED AT 337 AM EDT SUN MAY 3 2015

WITH TEMPS INTO THE UPPER 70S AND A DRY AIR MASS...THE FIRE DANGER
WILL BE AT ELEVATED LEVELS TODAY.  HOWEVER WINDS ARE NOT EXPECTED TO
BE TOO HIGH TODAY...GENERALLY REMAINING UNDER 15 MPH.

&&

.HYDROLOGY...
ISSUED AT 1136 AM EDT SUN MAY 3 2015

RIVERS ARE RUNNING WELL WITHIN BANKS AND REMAIN STEADY...IF NOT
FALLING EVER-SO-SLIGHTLY. THOUGH FLOODING IS NOT ANTICIPATED AT
THIS TIME...THE PATTERN BECOMES ACTIVE OVER THE COURSE OF THE
UPCOMING WEEK AND WE MAY SEE WITHIN BANK RISES.

PRECIPITATION IS EXPECTED TO DEVELOPED AND PROGRESS FROM NORTH TO
SOUTH BEGINNING LATE TONIGHT. THE FRONTAL BOUNDARY RESPONSIBLE FOR
THE PRECIPITATION WILL STALL NEAR THE SOUTHERN LOWER MICHIGAN
BORDER WHICH WILL LEAD TO SOME OF THE HIGHER TOTALS ALIGNING ALONG
AND SOUTH OF I-94. THIS FRONT THEN RETURNS NORTH NEAR MIDWEEK AND
PROVIDES ANOTHER DECENT SHOT AT PRECIPITATION FOR CENTRAL LOWER
MICHIGAN DURING THAT TIME FRAME. YET ANOTHER ROUND OF WET WEATHER
IS POISED TO MOVE THROUGH LATE IN THE WEEK AND INTO NEXT WEEKEND.

THE MAIN IMPACTS WOULD LIKELY BE MINOR AND NOT REALLY FELT UNTIL WE
GET INTO THE NEW WORK WEEK. LOCATIONS THAT ARE ALREADY RAIN SOAKED
AND RECEIVE ANY ADDITIONAL CONVECTIVE PRECIPITATION COULD SEE
MINOR PONDING ON ROADWAYS...OR LOW LYING AREAS THAT ARE TYPICALLY
AFFECTED BY HEAVIER RAIN. AN ADDITIONAL NOTE IS THAT WE ARE DRY NOW
AND GREEN-UP IS OCCURRING IN MANY LOCATIONS. THIS WILL DEFINITELY
HELP IN TAKING UP A LOT OF THE MOISTURE THAT FALLS.

&&

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

$$

SYNOPSIS...JK
SHORT TERM...JK
LONG TERM...HOVING
AVIATION...LAURENS
FIRE WEATHER...JK
HYDROLOGY...JAM
MARINE...JK








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