Area Forecast Discussion
Issued by NWS Grand Rapids, MI

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
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 251648
AFDGRR

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GRAND RAPIDS MI
1248 PM 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 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1247 PM EDT SAT OCT 25 2014

SKIES CONTINUE TO CLEAR FROM NORTH TO SOUTH BEHIND THE COLD FRONT
EARLY THIS AFTERNOON. BY 20Z ALL TAF SITES SHOULD BE CLEAR WITH
GUSTY WEST NORTHWEST WINDS. TONIGHT INTO SUNDAY THE SURFACE RIDGE
MOVES INTO THE AREA SO WINDS WILL DECREASE SIGNIFICANTLY BUT SKIES
SHOULD REMAIN CLEAR INTO SUNDAY AFTERNOON. SO EXPECT VFR CONDITIONS
AT ALL TAF SITES FROM 20Z TODAY THROUGH 18Z SUNDAY.

&&

.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 1157 AM EDT SAT OCT 25 2014

DRY CONDITIONS WILL HOLD THROUGH MUCH OF THE WEEKEND WHILE THE
UPCOMING WEEK GETS A BIT MORE ACTIVE.

PRECIPITATION CHANCES WILL INCREASE GOING INTO LATE SUNDAY
NIGHT. SHOWERS AND A FEW STORMS MAY DEVELOP WHICH COULD TOTAL ONE
TENTH TO ONE QUARTER OF AN INCH OF RAIN. A BRIEF LULL IS EXPECTED
DURING THE DAY MONDAY...AHEAD OF A STRONG COLD FRONT THAT IS
ANTICIPATED TO MOVE THROUGH LATE MONDAY NIGHT AND TUESDAY MORNING.
THIS SHOULD BRING ADDITIONAL PRECIPITATION TO THE REGION WITH
ANOTHER QUARTER INCH OR SO OF RAIN. PRECIPITATION TOTALS WILL
BE DEPENDENT ON ANY THUNDERSTORM DEVELOPMENT...MEANING THAT
THUNDERSTORM AFFECTED AREAS HAVE A GREATER CHANCE AND EXCEEDING
THE AFOREMENTIONED EXPECTATIONS. THAT SAID...RECENT DRY WEATHER
AND PROBABILITIES OF ANY BIG IMPACT PRECIPITATION IS LOW. NO RIVER
FLOODING IS ANTICIPATED AT THIS TIME.

&&

.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...WDM
HYDROLOGY...JAM
MARINE...DUKE






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