Area Forecast Discussion
Issued by NWS Grand Rapids, MI

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FXUS63 KGRR 051137
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
737 AM EDT SUN JUL 5 2015

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 329 AM EDT SUN JUL 5 2015

THE REST OF THE HOLIDAY WEEKEND WILL FEATURE MOSTLY CLEAR SKIES
AND WARMER TEMPERATURES. DEPARTING HIGH PRESSURE WILL RESULT IN
WINDS BECOMING SOUTHERLY AND THAT WILL BRING IN WARMER AIR. HIGHS
SHOULD BE IN THE MID 80S INLAND OF THE BEACHES TODAY. TOMORROW A
COLD FRONT WILL BE HEADING THIS WAY. THE STRONG SOUTHERLY FLOW OF
AIR AHEAD OF THE FRONT WILL BRING TEMPERATURES TO THERE WARMEST
LEVELS SO FAR THIS YEAR. INLAND AREAS COULD SEE HIGHS NEAR 90 AS
THE CLOUDS AND PRECIPITATION FROM THE COLD FRONT WILL NOT ARRIVE
UNTIL AFTER MIDNIGHT.

SHOWERS AND THUNDERSTORMS ARE EXPECTED TUESDAY MORNING AS THE COLD
FRONT COMES THROUGH THE AREA...THEN EXPECT PLEASANT WEATHER THE
REST OF THE WEEK. THE NEXT THREAT OF SHOWERS WILL BE NEXT WEEKEND.

&&

.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 329 AM EDT SUN JUL 5 2015

THE PRIMARY ISSUE WITH THIS FORECAST IS THE PRECIPITATION WITH THE
COLD FRONT MONDAY NIGHT INTO TUESDAY. A LESSER ISSUE IS THE CHANCE
FOR HIGHS NEAR 90 ON MONDAY. HEAT INDEX VALUES WILL BE PUSHING 95
DEGREES INLAND OF LAKE MICHIGAN DURING IN THE AFTERNOON.

THE MODELS HAVE COME INTO BETTER AGREEMENT ON THE WEATHER WITH THE
COLD FRONT MONDAY NIGHT INTO TUESDAY. IT SEEMS THE GREATEST THREAT
FOR SHOWERS WITH THE FRONT WILL BE BETWEEN MIDNIGHT AND NOON...
HELPED BY THE RIGHT ENTRANCE REGION OF THE POLAR JET. IT IS THAT
FEATURE THAT GIVES ME HOPE MOST AREAS WILL IN FACT SEE SOME
MEASURABLE RAIN FROM THIS SYSTEM. PRECIPITABLE WATER SOARS TO
AROUND 2 INCHES...WHICH IS MORE MORE THAN DOUBLE NORMAL. THE
MOISTURE TRANSPORT VECTORS ARE ACTUALLY AIMED AT UPPER MICHIGAN
(WHERE THE BEST DYNAMICS ARE) BUT THEY TO COME THROUGH THIS AREA
SO I DO BELIEVE WE WILL SEE RAIN FROM THIS EVENT.

AS FOR SEVERE STORMS...THE NAM12 IS DOING IT`S TYPICAL THING OF
HAVING TO MUCH MOISTURE AT LOW LEVELS... THAT RESULT IN MOST
UNSTABLE CAPES OVER 2000 J/KG EARLY TUESDAY MORNING AS THE FRONTAL
RAIN BAND MOVES THROUGH. HOWEVER THE ECMWF AND GFS ARE NOT NEARLY
AS UNSTABLE... IN FACT THE GFS HAVE NEARLY NO CAPE AT ALL DURING
THIS TIME. ALSO AGASINST STRONG STORMS IS THE LOW LEVEL JET IS
FOCUSED ON NORTHERN LOWER AND UPPER MICHIGAN. SOUTHWEST MICHIGAN
IS AS TYPICAL...IN THE AREA OF SPEED DIVERGENCE. ALL OF THIS
TELLS ME THIS WILL BE MORE OF A RAIN EVENT THAN A THUNDERSTORM
EVENT.

OTHERWISE QUIET WEATHER TODAY THROUGH MOST OF MONDAY AS THE HIGH
MOVES OFF TO OUR EAST WITH INCREASING SOUTHERLY FLOW. THIS
SOUTHERLY FLOW SHOULD MIX OUT THE SMOKE FROM THE CANADIAN FOREST
FIRES BY MIDDAY MONDAY. THAT WILL ALSO HELP GET TEMPERATURES TO
PUSH 90 BY LATE AFTERNOON. THE DEEP MIXING (TO NEAR 725 MB) WILL
ALSO HELP THAT CAUSE.

BOTTOM LINE SUNNY AND WARMER TODAY AND MONDAY... SHOWERS AND
THUNDERSTORMS TUESDAY MORNING.

.LONG TERM...(TUESDAY NIGHT THROUGH SATURDAY)
ISSUED AT 329 AM EDT SUN JUL 5 2015

THE MID WEEK PERIOD WILL SEE TEMPERATURES RUN 5 TO 10 DEGREES BELOW
NORMAL WITH THE UPPER FLOW MAINLY ZONAL.  HIGH PRESSURE WILL BE IN
CONTROL...SO THE PLEASANT TEMPERATURES WILL BE ACCOMPANIED BY DRY
WEATHER.

BY THURSDAY/FRIDAY A SURFACE BOUNDARY TO OUR SOUTH TRIES TO INCH
NORTHWARD AS A WAVE OF LOW PRESSURE MAY MOVE ALONG IT.  FOR THE MOST
PART WE SHOULD REMAIN DRY...BUT SOME ISOLATED OR WIDELY SCATTERED
SHOWERS/STORMS CAN NOT BE RULED OUT...MAINLY ALONG I-94.

IT APPEARS WE WILL HAVE A BETTER CHANCE OF SHOWERS/STORMS INTO
FRIDAY NIGHT AND SATURDAY AS DEEPER FLOW OFF THE GULF DEVELOPS ALONG
WITH THE ARRIVAL OF A DECENT LOOKING SHORT WAVE.

TEMPERATURES SHOULD RETURN TO CLOSE TO NORMAL BY THURSDAY NIGHT
THROUGH SATURDAY.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 737 AM EDT SUN JUL 5 2015

ONCE THE EARLY MORNING FOG MIXES OUT (14Z) I EXPECT VFR CONDITIONS
(CLEAR SKIES AND UNLIMITED VISIBILITIES ) THROUGH 12Z MONDAY. TONIGHT
I DO NOT EXPECT THE FOG TO REDEVELOP LIKE IT DID THIS MORNING AS
THERE IS MORE WIND IN THE BOUNDARY LAYER.

&&

.MARINE...
ISSUED AT 329 AM EDT SUN JUL 5 2015

I CONTINUED THE FOG IN THE NEAR SHORE WATERS THROUGH MONDAY AS DEW
POINTS SHOULD BE ABOVE WATER TEMPERATURES. WEB CAMS EARLY THIS
EVENING SHOWED FOG ISSUES SO I SEE NO REASON TO BELIEVE IT SHOULD
BE GONE NOW.

WE MAY NEED SOME SORT OF SMALL CRAFT ADVISORY MONDAY AS SOUTH
WINDS INCREASE TO 15 TO 25 KNOTS. THERE WILL BE A MODERATE BEACH
HAZARD RISK TOO...THAT WILL ALSO HAVE TO BE MONITORED.


&&

.HYDROLOGY...
ISSUED AT 1124 AM EDT SAT JUL 4 2015

THERE ARE NO EXISTING ADVISORIES ON AREA RIVERS. IMPROVEMENT IS
EXPECTED TO CONTINUE AT LEAST THROUGH THE WEEKEND.

OVERALL...DRY CONDITIONS WILL DOMINATE THE PATTERN THROUGH THE
FIRST HALF OF MONDAY. THERE IS A SLIGHT CHANCE OF AN ISOLATED
STORM THIS AFTERNOON THROUGH INTERIOR PORTIONS OF LOWER MICHIGAN.
BETTER CHANCES OF RAIN EXIST LATE MONDAY INTO EARLY TUESDAY WHEN A
COLD FRONT SWEEPS THROUGH THE AREA. A DECENT RAINFALL IS POSSIBLE
MONDAY BUT GIVEN THE RECENT PERIOD OF DRY WEATHER THIS SHOULD NOT
BE MUCH OF A CONCERN. AMOUNTS IN THE REALM OF ONE- HALF TO THREE-
QUARTERS OF AN INCH ARE POSSIBLE. AMOUNTS MAY VARY IN OR NEAR
THUNDERSTORMS.

&&

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

$$

SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...JK
AVIATION...WDM
HYDROLOGY...JAM
MARINE...WDM


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