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 251153
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
753 AM EDT SAT OCT 25 2014

LATEST UPDATE...
AVIATION

.SYNOPSIS...
ISSUED AT 336 AM EDT SAT OCT 25 2014

A RATHER BREEZY DAY CAN BE EXPECTED TODAY AS A COLD FRONT SWEEPS
THROUGH THE AREA. NO PRECIPITATION IS EXPECTED WITH THE FRONTAL
PASSAGE. HIGHS WILL PUSH INTO THE LOWER 60S TODAY WHICH IS ACTUALLY
ABOVE NORMAL FOR THIS TIME OF YEAR. HIGHS WILL ONLY REACH THE 50S ON
SUNDAY WITH DRY AND FAIR WEATHER EXPECTED. A WARM FRONT SURGING INTO
THE REGION WILL BRING SHOWERS AND STORMS TO THE AREA FOR SUNDAY
NIGHT INTO MONDAY. HIGHS ON MONDAY WILL PUSH INTO THE LOWER 70S
ACROSS SOUTHERN LOWER MICHIGAN. ADDITIONAL SHOWERS AND STORMS ARE
EXPECTED MONDAY NIGHT INTO TUESDAY MORNING. MUCH COOLER WEATHER WILL
SETTLE INTO THE AREA FOR THE LATTER HALF OF THE UPCOMING WORK WEEK.

&&

.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 336 AM EDT SAT OCT 25 2014

LIMITED WEATHER CONCERNS TODAY THROUGH SUNDAY AS A COLD FRONT PASSES
THROUGH DRY TODAY AND HIGH PRESSURE BUILDS IN FOR TONIGHT AND
SUNDAY. SKIES WILL GRADUALLY CLEAR OUT TODAY WITH INCREASING AMOUNTS
OF SUNSHINE AS WE MOVE THROUGH THE AFTERNOON. MAINLY CLEAR SKIES ARE
EXPECTED TONIGHT AND SUNDAY.

THE MAIN FOCUS OF THE SHORT TERM IS ON CHANCES FOR SHOWERS AND
STORMS AS A WARM FRONT MOVES IN SUNDAY NIGHT. 30-40 PCT POPS AREA
WIDE FOR SHOWERS AND STORMS SEEMS REASONABLE SUNDAY NIGHT GIVEN THE
SURGE OF MOISTURE. 850MB DEW POINTS RISE RAPIDLY INTO THE LOWER
TEENS C. RISES OF THE MAGNITUDE FORECAST FOR SUNDAY NIGHT USUALLY
RESULT ON DECENT COVERAGE OF CONVECTION. THE 850MB MOISTURE
TRANSPORT IS NOT OFF THE CHARTS...BUT IS SOLID...AS IS THE LLJ. A
30KT LLJ IS NOSING IN MONDAY MORNING.

THE LLJ RAMPS UP FURTHER ON MONDAY WITH 35-40 KNOTS IN PLACE FOR THE
AFTERNOON. CONTINUED THE CHANCE POPS AREA WIDE FOR MONDAY. DEEP
LAYER MOST UNSTABLE CAPE VALUES ALSO SUPPORT THUNDERSTORM CHANCES
BOTH PERIODS (SUNDAY NIGHT AND MONDAY). AT THIS POINT NOT EXPECTING
ANYTHING SEVERE. SHEAR VALUES ARE DECENT BOTH SUNDAY NIGHT AND
MONDAY...BUT THE MAX IS REACHED A DAYBREAK ON MONDAY WHICH IS A
USUAL RELATIVE MINIMUM IN SEVERE ACTIVITY. 0-6KM BULK SHEAR REACHES
50 KNOTS.

.LONG TERM...(MONDAY NIGHT THROUGH FRIDAY)
ISSUED AT 336 AM EDT SAT OCT 25 2014

THE MODELS REMAIN ON THE SAME PAGE...SHOWING A STRONG COLD FRONT
COMING THROUGH SW MI TUESDAY MORNING.  THIS SYSTEM WILL HAVE GOOD
JET DYNAMICS IN THE LOWER AND UPPER ATMOSPHERE...SO EXPECT LIKELY TO
HIGH CHANCE POPS WILL WORK WITH THIS FROPA.  THE MODELS CONTINUE TO
TREND COLDER BEHIND THE FRONT...SO TUESDAY AFTERNOON SHOULD SEE
FALLING TEMPS FROM A MORNING HIGH IN THE UPPER 50S TO MID 60S.

WE SHOULD SEE A BRIEF PERIOD OF LAKE EFFECT LATE TUESDAY NIGHT/EARLY
WEDNESDAY AS H8 TEMPS PLUNGE TO AROUND -3C.  THIS SHOULD BE A
SHORT WINDOW HOWEVER AS ANTICYCLONIC FLOW DEVELOPS BY MID DAY
WEDNESDAY ALONG WITH SURFACE HIGH PRESSURE BUILDING IN.

THEN A SHARPENING SHORT WAVE IS PROGGED TO REACH THE REGION BY
THURSDAY NIGHT.  H8 TEMPS DROP EVEN FURTHER BEHIND THIS SYSTEM TO
AROUND -7C BY FRIDAY.  BELIEVE WE STAND A CHANCE OF SEEING
RAIN...POSSIBLY MIXED WITH OR CHANGING TO SNOW OVER THE INTERIOR
NORTH THURSDAY NIGHT INTO FRIDAY.  WE WILL HAVE TO SEE IF THIS
COLDER TREND CONTINUES...IF SO WE WILL HAVE TO EXPAND THE MENTION OF
SNOW FURTHER SOUTH.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 750 AM EDT SAT OCT 25 2014

SOME MVFR CLOUDS REMAIN ACROSS SOUTHWEST LOWER MICHIGAN AT
12Z...BUT THE TREND WILL BE TO CLEAR THESE OUT THROUGH THE COURSE
OF THE MORNING. BY NOON...EXPECTING MOST AREAS TO BE MOSTLY CLEAR.
CLEAR SKIES ARE THEN ANTICIPATED WITH VFR CONDITIONS PERSISTING FROM
THIS AFTERNOON THROUGH THE NIGHT.

THE OTHER MAIN STORY WILL BE THE GUSTY WESTERLY WINDS TODAY. FROM
ABOUT 15Z THROUGH 23Z...12-25 KNOT WEST WINDS CAN BE EXPECTED WITH
A FEW POSSIBLE GUSTS TOWARDS 30 KNOTS.


&&

.MARINE...
ISSUED AT 336 AM EDT SAT OCT 25 2014

OPTED TO ISSUE A SMALL CRAFT ADVISORY FROM LATE THIS AFTERNOON
THROUGH SUNDAY AFTERNOON. NORTHWEST WINDS BEHIND A COLD FRONTAL
PASSAGE THIS MORNING WILL RISE INTO THE 15 TO 25 KNOT RANGE. THE
CORE OF THE WIND IS EXPECTED TO MOVE THROUGH THE AREA THIS EVENING.
WAVES WILL LIKELY PEAK IN THE 4 TO 6 FOOT RANGE. WINDS AND WAVES
WILL SUBSIDE SUBSTANTIALLY SUNDAY AFTERNOON INTO SUNDAY EVENING AS
HIGH PRESSURE BUILDS IN.


&&

.HYDROLOGY...
ISSUED AT 336 AM EDT SAT OCT 25 2014

NO HYDRO CONCERNS ARE ANTICIPATED THROUGH THE NEXT 3 TO 5 DAYS. THAT
SAID...SHOWER AND THUNDERSTORMS ARE EXPECTED IN THE SUNDAY NIGHT
THROUGH TUESDAY TIME FRAME. RAINFALL AMOUNTS DURING THIS PERIOD WILL
LIKELY RANGE FROM AROUND A QUARTER OF AN INCH TO AROUND THREE
QUARTERS OF AN INCH. WITH RIVER LEVELS CURRENTLY AROUND NORMAL AND
WELL WITHIN BANK WE DO NOT ANTICIPATE ANY RIVER OR FLOOD ISSUES.
PWAT VALUES ARE STILL EXPECTED TO RISE TO AROUND 1.25 INCHES...SO
THERE WILL BE SOME LOCALLY HEAVY DOWNPOURS WITH STORMS.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY FROM 5 PM THIS AFTERNOON TO 5 PM EDT SUNDAY
     FOR LMZ844>849.

&&

$$

SYNOPSIS...DUKE
SHORT TERM...DUKE
LONG TERM...JK
AVIATION...DUKE
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.