Area Forecast Discussion
Issued by NWS Gaylord, MI

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000
FXUS63 KAPX 011954
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
354 PM EDT WED OCT 1 2014

.SYNOPSIS...
ISSUED AT 354 PM EDT WED OCT 1 2014

ANOTHER STORM SYSTEM WILL ORGANIZE AND SWING INTO THE REGION LATE
THIS WEEK AND INTO THE WEEKEND. THIS WILL SET THE STAGE FOR A
PROLONGED PERIOD OF WET AND COOL WEATHER...WITH SIGNIFICANT RAINFALL
FOR LATE THURSDAY THROUGH FRIDAY.

&&

.SHORT TERM...(THIS EVENING THROUGH TONIGHT)
ISSUED AT 354 PM EDT WED OCT 1 2014

...RAIN TO ARRIVE AFTER MIDNIGHT...

HIGH IMPACT WEATHER POTENTIAL: MINIMAL.

PATTERN SYNOPSIS/FORECAST: EARLY AFTERNOON SURFACE ANALYSIS SHOWS A
COLD/OCCLUDED FRONT RUNNING NORTH-SOUTH FROM CENTRAL MANITOBA
THROUGH THE EASTERN DAKOTAS AND EASTERN PORTIONS OF NEBRASKA/
KANSAS.  SUPPORTING SHORT WAVE TROUGH CROSSING THE NEBRASKA/IOWA
BORDER WITH A 90KT JET STREAK OVER MINNESOTA.  HIGH PRESSURE OVER
QUEBEC RIDGES BACK TO THE WEST INTO THE GREAT LAKES.  PLUME OF
DEEPER MOISTURE ADVECTING NORTHWARD ALONG/AHEAD OF THE FRONT
(1.00-1.50 INCH PRECIPITABLE WATER VALUES INTO THE UPPER MISSISSIPPI
VALLEY)...SUPPORTING A BAND OF RAIN FROM NORTHERN MISSOURI/EASTERN
PORTIONS OF IOWA AND MINNESOTA/NORTHWEST WISCONSIN.  MUCH DRIER AIR
ALOFT ACROSS MICHIGAN...BUT MOISTURE TRAPPED BENEATH A SUBSIDENCE
INVERSION CENTERED BETWEEN 850-900MB HAS BEEN KEEPING NORTHERN
MICHIGAN SOCKED IN UNDER LOW CLOUDS WITH A FEW THIN "STREAKS" TRYING
TO DEVELOP OVER NORTHERN LOWER...AS STRATUS MIXES INTO A
STRATOCUMULUS DECK.

SHORT WAVE TROUGH OVER WESTERN IOWA FORECAST TO TRACK NORTHEAST
ACROSS WISCONSIN/UPPER MICHIGAN TONIGHT...WHILE ASSOCIATED COLD
FRONT MOVES SLOWLY EAST INTO THE UPPER MISSISSIPPI VALLEY.

PRIMARY FORECAST CONCERNS: INITIAL LEFTOVER CLOUD COVER...THEN
INITIAL EVOLUTION OF THE UPCOMING RAIN THREAT.

TONIGHT...TO START...GETTING SOME INCREASING BREAKS IN THE CLOUD
COVER OVER NORTHWEST LOWER AS CLOUD DECK GETTING MORE OF A
CONVECTIVE LOOK TO IT.  IF THIS TREND CONTINUES MAY BE A PERIOD OF
TIME OF PARTLY CLOUDY SKIES THIS EVENING BEFORE UPSTREAM MID/HIGH
CLOUDS SPREAD INTO NORTHERN MICHIGAN...AT LEAST ACROSS NORTHWEST
LOWER MICHIGAN.  INCREASING MOISTURE INFLOW INTO MICHIGAN TONIGHT AS
UPSTREAM COLD/OCCLUDED FRONT SLOWLY TRACKS EAST INTO THE UPPER
MISSISSIPPI VALLEY (PRECIPITABLE WATER EXPECTED TO INCREASE ABOVE
1.25 INCH AFTER MIDNIGHT).  WHILE STRONGER FORCING ASSOCIATED WITH
LEAD SHORT WAVE TROUGH WILL PASS MOSTLY WEST OF THE FORECAST
AREA...SOME JET FORCING/UPPER DIVERGENCE AND ISENTROPIC ASCENT
EXPECTED TO SHEPHERD MISSISSIPPI VALLEY RAIN BAND EAST INTO THE
FORECAST AREA AFTER MIDNIGHT.  TIMING TRENDS APPEAR TO BE PRETTY
STEADY...WHICH SHOULD KEEP RAINFALL OUT OF AREAS EAST OF M-33 UNTIL
THURSDAY MORNING.

&&

.LONG TERM...(THURSDAY THROUGH WEDNESDAY)
ISSUED AT 354 PM EDT WED OCT 1 2014

...HERE COMES FALL (AGAIN)...

HIGH IMPACT WEATHER POTENTIAL: THUNDERSTORMS POSSIBLE THURSDAY
NIGHT...FOLLOWED BY A PERIOD OF NOT-SO-NICE CONDITIONS INTO THE
WEEKEND WITH WELL BELOW NORMAL TEMPS AND WINDY CONDITIONS. A PERIOD
OF GALES STILL APPEARS POSSIBLE PERHAPS THURSDAY NIGHT AND AGAIN
FRIDAY NIGHT INTO SATURDAY.

PATTERN SUMMARY/EVOLUTION: WELL NORTHERN MICHIGAN...WE ALL KNEW WE
WOULD HAVE TO PAY FOR OUR RECENT STRETCH OF DOWNRIGHT GORGEOUS LATE
SUMMER WEATHER...AND OUR PAYMENT HAS COME DUE. BROAD UPPER TROUGHING
OVER THE ROCKIES AND PLAINS WILL LINK UP WITH ADDITIONAL STRONG
ENERGY ROLLING THROUGH WESTERN CANADA AT THE MOMENT TO HELP CARVE
OUT QUITE THE DEEP TROUGH CENTERED OVER THE GREAT LAKES THROUGH THE
WEEKEND. THIS SETUP WILL UNLOAD QUITE THE CHILLY AIR MASS IN OUR
DIRECTION...USHERED IN BY THE PASSAGE OF A STRONG COLD FRONT
SOMETIME FRIDAY MORNING. OF COURSE SEVERAL RAIN CHANCES WILL
ACCOMPANY THAT BOUNDARY...AS WILL ADDITIONAL PRECIPITATION INTO THE
WEEKEND AS WE CRANK UP THE LAKE EFFECT/ENHANCEMENT MACHINE. UPPER
TROUGHING LOOKS TO LINGER INTO EARLY NEXT WEEK...THOUGH WITH PERHAPS
A BIT OF RELAXATION AS HIGHER HEIGHTS PUSH BACK TOWARD THE AREA. OF
COURSE...THAT IS TYPICAL THIS TIME OF YEAR AS WE ARE IN OUR CLASSIC
ROLLER COASTER UP/DOWN TRANSITION SEASON.

A LOOK AT THE FORECAST DETAILS:

THURSDAY-FRIDAY: AN ACTIVE STRETCH FOR SURE. LEAD UPPER VORT OVER
IOWA TODAY WILL LIFT INTO LAKE SUPERIOR...DRAGGING A NOTABLE SURGE
OF THERMAL/MOISTURE ADVECTION INTO NORTHERN MICHIGAN ON THURSDAY.
THAT SETUP SHOULD DELIVER A LEAD BAND OF RAIN SHOWERS...AIDED IN
SOME RESPECT BY A BIT OF UPPER JET SUPPORT...PARTICULARLY FOR THE
WESTERN HALF OF THE AREA. SAID RAIN SHIELD WILL LIKELY WEAKEN WITH
EASTWARD EXTENT AS IT OUTRUNS THE BETTER FORCING AND ENCOUNTERS AN
INITIALLY MUCH DRIER AIR MASS. HIGHEST POPS WEST OF I-75 LOOK JUST
FINE...TAPERING TO LOWER LIKELIES EAST...THOUGH NOT ENTIRELY
POSITIVE FAR EASTERN AREAS WILL SEE MEASURABLE PRECIP. THUNDER
THREAT IS VERY LOW DESPITE A NICE INFLUX OF MOISTURE...WITH VERY
SKINNY CAPE PROFILES UP TO PERHAPS 100 J/KG SUPPORTIVE OF SOME
BETTER CONVECTIVE ELEMENTS BUT NO OUTRIGHT THUNDER CHANCE. HIGHS ARE
TRICKY AND WILL ULTIMATELY DEPEND ON PRECIP EVOLUTION. COULD BE SOME
SNEAKY WARM VALUES FAR EASTERN AREAS WHERE RAIN ARRIVES LATER...WITH
MAYBE SOME LATER DAY HEATING IN THE POST-RAIN ENVIRONMENT IF WE CAN
MANAGE A LITTLE BIT OF SUNSHINE. OVERALL...NOTHING TOO CRAZY...AND
CERTAINLY NOT AS WARM AS THINGS APPEARED SEVERAL DAYS AGO. GUESS
THAT`S QUITE TYPICAL FOR OCTOBER.

A MUCH MORE WIDESPREAD RAIN SHIELD SHOULD ARRIVE THURSDAY NIGHT...
ESPECIALLY AFTER MIDNIGHT...AS A MUCH STRONGER UPPER TROUGH AND
SURFACE WAVE APPROACH. QUITE THE PUSH OF DEEP LAYER WARM ADVECTION
ASCENT AND IMPRESSIVE MOISTURE (PWATS IN EXCESS OF 1.5 INCHES - 3SD
ABOVE NORMAL) COUPLED WITH  NICE PUNCH OF UPPER JET FORCING
INCREASES CONFIDENCE THAT IT WILL RAIN FOR ALL AREAS...PERHAPS
SUBSTANTIALLY SO. PARALLELING DEEP LAYER FLOW TO THE LOW LEVEL
BOUNDARY COMBINED WITH SUCH HIGH MOISTURE LEVELS RAISES AN EYEBROW
ABOUT THE POTENTIAL FOR LOCALIZED QUITE HEAVY RAINFALL...AND INDEED
WOULDN`T BE SHOCKED TO SEE SOME LOCALIZED SPOTS PICK UP AROUND 2
INCHES. IN ADDITION...THUNDER CHANCES LOOK TO INCREASE DURING THE
NIGHT WITH AN AXIS OF REDUCED STABILITY ROLLING NORTH. MOST UNSTABLE
CAPE VALUES UP AROUND 500-800 J/KG MANDATE A THUNDER INSERTION INTO
THE FORECAST...AND DEEP SHEAR VALUE UP AROUND 50 KNOTS ALSO PEAK
SOME INTEREST...THOUGH A FAIRLY STABLE BOUNDARY LAYER SHOULD LIMIT
THE ABILITY OF REALLY STRONG FLOW FROM MIXING DOWN. A VERY MILD
NIGHT WITH TEMPS ONLY IN THE 60S...WITH TEMPS FALLING FRIDAY
AFTERNOON AS COLD ADVECTION KICKS INTO GEAR WHILE RAIN TAPERS SLOWLY
WITH THE FRONTAL PASSAGE.

FRIDAY NIGHT-MONDAY: WELCOME BACK TO FALL! QUITE THE CHILLY AIR MASS
WILL DROP INTO THE AREA...WITH H8 TEMPS BOTTOMING OUT IN THE -2C TO
-5C RANGE PER MULTI-MODEL CONSENSUS. AT THE SAME TIME...ADDITIONAL
ENERGY DROPPING INTO THE MEAN TROUGH OVERHEAD LOOKS TO HELP CARVE
OUT AN EVEN DEEPER UPPER FEATURE THROUGH THE WEEKEND...PERHAPS
CLOSING OFF NEARBY AND HELPING WRAP ADDITIONAL SPOKES OF DEEPER
MOISTURE ACROSS THE AREA. SIMPLY PUT...THAT SPELLS PERIODS OF LAKE
EFFECT AND LAKE ENHANCED PRECIPITATION FROM FRIDAY NIGHT RIGHT ON
THROUGH THE WEEKEND...AND MAYBE EXTENDING INTO MONDAY AS WELL...
PENDING THE EVENTUAL TIMING OF THE UPPER TROUGH EXIT. AS USUAL...
IT IS HARD TO TIME EACH WING OF ENHANCED MOISTURE AND BETTER PRECIP
CHANCES...BUT AT THE MOMENT FRIDAY NIGHT INTO SATURDAY LOOK TO BE
PRIME CANDIDATES FOR WIDESPREAD LAKE ENHANCEMENT...WITH MORE OF A
PURE LAKE EFFECT LOOK THE REST OF THE WEEKEND. DON`T REALLY WANT TO
TALK MUCH ABOUT IT...BUT THE DEGREE OF COLDER AIR DOES AT LEAST
PROVIDE A SMALL CHANCE A COUPLE SNOWFLAKES COULD MIX IT...ESPECIALLY
SATURDAY NIGHT. CERTAINLY NOTHING WORTH MENTIONING JUST YET...AND
WOULD LIKE TO BEE JUST A SLIGHTLY COOLER BOUNDARY LAYER (H8 TEMPS
AROUND -6C OR A TOUCH COLDER THIS TIME OF YEAR)...BUT THE CHANCE
ALSO ISN`T ZERO. GRAUPEL ALSO POSSIBLE WITH ANY CONVECTIVE
ELEMENTS...AND WATERSPOUTS ALSO APPEAR POSSIBLE WITH DEEP OVER-LAKE
CONVECTIVE DEPTH EXPECTED AND PLENTY OF AMBIENT VORTICITY OVERHEAD.

TUESDAY-WEDNESDAY: A TIME OF MUCH LOWER CONFIDENCE WITH PLENTY OF
DISAGREEMENT REGARDING THE EVOLUTION OF UPPER TROUGHING. GFS
CONTINUES ITS EARLIER TRENDS OF HOLDING THE MEAN TROUGH INTACT OVER
THE GREAT LAKES WHILE THE ECMWF CONTINUES TO TREND GRADUALLY WARMER.
BASED ON THE FACT THAT THE INITIAL PATTERN WILL BE SO BLOCKY AND OUR
PROPENSITY FOR STUBBORN TROUGHING THE PAST 12 MONTHS...HAVE TO
BELIEVE CHANCES ARE FAIRLY HIGH THAT WE END UP COOLER AND PERHAPS
EVEN A BIT UNSETTLED.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 134 PM EDT WED OCT 1 2014

IFR CONDITIONS AT APN/PLN EXPECTED TO LIFT TO MVFR OVER THE NEXT
COUPLE OF HOURS...THEN VFR THIS EVENING. MVFR CONDITIONS AT
TVC/MBL EXPECTED TO LIFT TO VFR CONDITIONS LATER THIS AFTERNOON.
RAIN EXPECTED TO ARRIVE INTO NORTHWEST LOWER BY THURSDAY MORNING.

&&

.MARINE...
ISSUED AT 354 PM EDT WED OCT 1 2014

PERSISTENT SOUTHEAST WINDS EXPECTED TONIGHT AND THURSDAY...INCREASING
THURSDAY NIGHT AHEAD OF AN APPROACHING COLD FRONT WHICH WILL BACK
WINDS AROUND TO THE WEST ON FRIDAY. SMALL CRAFT ADVISORIES MAY BE
NEEDED BY THURSDAY NIGHT PRIOR TO COLD FRONT PASSAGE AS WINDS AND
WAVES BUILD. GUSTY WINDS WILL CONTINUE FRIDAY...WITH THE
POSSIBILITY OF WATERSPOUTS HEADING INTO THE WEEKEND.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.

&&

$$

SYNOPSIS...AM
SHORT TERM...JPB
LONG TERM...LAWRENCE
MARINE...LAWRENCE





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