Area Forecast Discussion
Issued by NWS Grand Rapids, MI

Home | Current Version | Previous Version | Text Only | 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 231721
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
121 PM EDT THU OCT 23 2014

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 330 AM EDT THU OCT 23 2014

THE WEATHER WILL REMAIN RELATIVELY QUIET BY OCTOBER STANDARDS
THROUGH THE WEEKEND. HIGH PRESSURE WILL BRING FAIR WEATHER TODAY
WITH A GOOD DEAL OF SUNSHINE. TONIGHT A WEAK TROUGH OF LOW PRESSURE
WILL PROVIDE SOME LIGHT RAIN SHOWERS ALTHOUGH AMOUNTS WILL BE LIGHT.
SKIES WILL TURN PARTLY SUNNY ON FRIDAY WITH A COLD FRONT SET TO MOVE
THROUGH LATE FRIDAY NIGHT AND SATURDAY MORNING. AT THIS POINT IT
LOOKS LIKE THE FRONT WILL SLIDE THROUGH DRY FRIDAY NIGHT AND
SATURDAY. HIGH TEMPERATURES THE REST OF THIS WEEK AND INTO THE
WEEKEND WILL REMAIN NEAR TO SLIGHTLY ABOVE NORMAL IN THE 50S TO
AROUND 60.

&&

.UPDATE...
ISSUED AT 1019 AM EDT THU OCT 23 2014

WE HAVE ALLOWED THE DENSE FOG ADVISORY TO COME TO AN END ACROSS
THE ENTIRE AREA. THERE ARE A FEW OBSERVATIONS AT THE AIRPORTS
STILL INDICATING VSBYS AROUND 1/4SM...HOWEVER CONDITIONS ARE
GENERALLY IMPROVING QUICKLY ACROSS THE AREA. AN EXAMPLE IS KGRR
STILL REPORTING 3/4SM AT 1416Z...HOWEVER CONDITIONS AROUND MOST OF THE
AIRPORT HAVE IMPROVED MUCH MORE AT THE SAME TIME.

WE WILL MAINTAIN A DRY FCST FOR THE DAY TODAY. MOST OF THE LATEST
MODEL GUIDANCE IS SHOWING THE THREAT FOR RAIN SHOWERS COMING IN
AFTER 00Z ACROSS THE LAKESHORE. WITH THE CURRENT MOVEMENT OF THE
RAIN SHOWERS IN WI MOVING MORE NORTH THAN EAST...IT WILL TAKE A
WHILE FOR PCPN TO MAKE IT TO THE AREA. ALSO...A DRY ATMOSPHERE IN
PLACE WILL ERODE THE PCPN AS IT TRIES TO MOVE TOWARD THE AREA..

UPDATE ISSUED AT 544 AM EDT THU OCT 23 2014

HAVE OPTED TO ISSUE A DENSE FOG ADVISORY FOR THE ENTIRE AREA
THROUGH 1000 AM. FOG HAS EXPANDED QUITE A BIT IN THE LAST HALF
HOUR WITH STRATUS BEGINNING TO SHOW UP IN THE FOG SATELLITE
PRODUCT WHICH IS INDICATIVE OF A MORE WIDESPREAD FOG. HAVE QUARTER
MILE VISIBILITIES IN ALL AREAS NOW AND IT WILL LIKELY EXPAND TO
AREAS NOT CURRENTLY SEEING IT. A LIGHT SOUTHEAST FLOW IS IN PLACE
IN THE LOWEST 50MB/S PER THE RUC13 AND THIS SHOULD ADVECT IT EVEN
TO THE LAKESHORE AREAS WITH TIME. WE STILL HAVE ABOUT 2.5 HOURS
BEFORE SUNRISE...SO IT SHOULD EXPAND AND BECOME MORE DENSE. NPWGRR
IS ALREADY OUT.

&&

.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 330 AM EDT THU OCT 23 2014

LIMITED CONCERNS IN THE SHORT TERM BUT THE FOCUS WAS ON EXTENT OF
FOG THIS MORNING...CHANCE FOR RAIN TONIGHT AND SPOTTY LIGHT RAIN
CHANCES SATURDAY MORNING.

AS FOR THE FOG...THINK WE ARE LOOKING AT PATCHY RADIATIONAL GROUND
FOG THIS MORNING. SEVERAL SITES ARE CURRENTLY AT A QUARTER OF A MILE
VISIBILITY SO WE WILL BE KEEPING AN EYE ON WHETHER OR NOT IT EXPANDS
AND BECOMES WORTHY OF A DENSE FOG ADVISORY. FOG SATELLITE PRODUCT IS
BEGINNING TO SHOW HINTS AT STRATUS FORMING.

REGARDING RAIN CHANCES TONIGHT...IT LOOKS ABOUT THE SAME AS THE LAST
FEW NIGHTS...30/40 PCT CHANCE ESPECIALLY IN THE WEST DURING THE
EVENING. A SHORTWAVE CURRENTLY SEEN IN THE WATER VAPOR IMAGERY OVER
THE DAKOTAS MOVES THROUGH OUT REGION TONIGHT. SOME WEAK MOISTURE
TRANSPORT OCCURS AT 850MB/S ALONG WITH A WEAK SURFACE TROUGH. FEEL
THE BEST CHANCES WILL OCCUR EARLY ALONG AND WEST OF HIGHWAY
131...BECOMING ISOLATED OVERNIGHT AND ENDING.

ANOTHER BRIEF SHOT AT SOME VERY LIGHT RAIN MAY COME LATE FRIDAY
NIGHT INTO SATURDAY MORNING AS A COLD FRONT TRAVERSES THE AREA. THE
MAIN UPPER SUPPORT WITH THIS FRONT IS WELL NORTH OF SOUTHWEST
LOWER...BUT THERE IS A PUSH OF SOME MOISTURE INTO THE AREA FROM THE
SOUTH. THE ECMWF IS PAINTING SOME VERY LIGHT PRECIP ALONG THE LAKE
MICHIGAN SHORE SATURDAY MORNING. KEPT THE FORECAST DRY AT THIS POINT
AS NOT CONFIDENT ENOUGH WE WILL SEE ANYTHING.

OTHERWISE...QUIET TODAY OUTSIDE OF SOME MORNING FOG. WE SHOULD
BECOME AT LEAST PARTLY SUNNY FRIDAY AFTERNOON AS THE DEEPER MOISTURE
PEELS OFF TO THE EAST.

.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 330 AM EDT THU OCT 23 2014

THE UPPER LOW MOVES TO EASTERN CANADA TO START THE EXTENDED PERIOD.
THIS WILL ALLOW UPPER AND SURFACE RIDGING TO BUILD OVER THE UPPER
MIDWEST.  THE CHILLY TEMPS WILL MOVE OUT OF THE REGION AS THIS
OCCURS WITH SOLID WARM ADVECTION BY SUNDAY NIGHT.  THE LATTER PART
OF THE WEEKEND CONTINUES TO LOOK DRY...BUT WE SHOULD SEE WARM
ADVECTION CLOUDS ARRIVE ON THE HEELS OF THIS WARMUP SUNDAY NIGHT
INTO MONDAY.

THE NEXT CHANCE OF RAIN SHOULD MOVE IN MONDAY OR MONDAY NIGHT.  THE
VIGOROUS SYSTEM THAT WAS NOTED ON WATER VAPOR THIS MORNING OFF THE
BRITISH COLUMBIA COAST SHOULD MOVE OVER THE ROCKIES AND HELP PUMP
WARM AND MOIST GULF AIR INTO THE REGION.  THERE IS POOR AGREEMENT IN
THE MODELS ON THE TIMING OF THIS SYSTEM INTO MID WEEK BUT IT APPEARS
A COLD FRONT COMES THROUGH TUESDAY OR TUESDAY NIGHT.  SO THE RAIN
CHANCES SHOULD PEAK IN THIS TIME FRAME.  ADDED THUNDER TO THE
FORECAST FOR TUESDAY GIVEN THE HIGHER TEMPS/DEWPOINTS EXPECTED WITH
THE ARRIVAL OF THE FRONT.  IT SHOULD TURN COLDER AGAIN ONCE THE
FRONT PASSES WITH HIGHS BACK INTO THE 50S BY WED.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 121 PM EDT THU OCT 23 2014

THE FOG AND LOW CLOUDS HAVE FINALLY MIXED OUT AND ALL TAF SITES
ARE VFR. I EXPECT VFR CONDITIONS TO PREVAIL INTO THE LATE NIGHT
HOURS. AFTER MIDNIGHT A WEAKENING FRONTAL BOUNDARY COMES THROUGH
SOUTHWEST MICHIGAN AND BRINGS IN AN AREA OF LOW CLOUDS AND REDUCED
VISIBILITIES WITH IT. WHILE THERE IS CURRENTLY A RAIN AREA WITH
THIS SYSTEM... I AM THINKING THE RAIN AREA WILL LARGELY DISSIPATE
BEFORE REACHING THE SOUTHWEST MICHIGAN TAF SITES. I DID PUT VCSH
AT MKG SINCE IT WOULD SEEM THAT WOULD BE THE MOSTLY LIKELY
LOCATION TO SEE ANY PRECIPITATION FROM THIS SYSTEM. ONCE THE LOW
CLOUDS MOVE IN THEY WILL BE SLOW TO LEAVE SO I ALLOWED THE LOW
CEILING AND VISIBILITIES TO PERSIST THROUGH 18Z TOMORROW.


&&

.MARINE...
ISSUED AT 330 AM EDT THU OCT 23 2014

NO MARINE CONCERNS TODAY THROUGH FRIDAY WITH HIGH PRESSURE SLIDING
EAST ALLOWING FOR LIGHT SOUTHERLY FLOW TO TAKE HOLD. THE NEXT CHANCE
FOR WINDS AND WAVES BECOMING AN ISSUE WILL BE FROM FRIDAY NIGHT INTO
SATURDAY AS A COLD FRONT SWEEPS THROUGH THE REGION. SATURDAY
ESPECIALLY...20-30 KNOT NORTHWEST WINDS CAN BE EXPECTED WHICH WILL
BOOST WAVE HEIGHTS.


&&

.HYDROLOGY...
ISSUED AT 330 AM EDT THU OCT 23 2014

STILL NOT EXPECTING ANY HYDRO ISSUES INTO EARLY NEXT WEEK. VERY
LIMITED RAIN IS EXPECTED THROUGH MONDAY. THE FIRST CHANCE FOR RAIN
WILL BE TONIGHT...BUT NOT EXPECTED TOTALS MORE THAN 0.05 ANYWHERE.
MAINLY DRY WEATHER IS FORECAST THROUGH THE WEEKEND. RIVER LEVELS
REMAIN LOW AT THE PRESENT TIME.

&&

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

$$

UPDATE...NJJ
SYNOPSIS...DUKE
SHORT TERM...DUKE
LONG TERM...JK
AVIATION...WDM
HYDROLOGY...DUKE
MARINE...DUKE






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