Area Forecast Discussion
Issued by NWS Gaylord, MI

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000
FXUS63 KAPX 200345
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
1145 PM EDT FRI SEP 19 2014

.SYNOPSIS...
ISSUED AT 359 PM EDT FRI SEP 19 2014

MODERATING TEMPERATURES ARE EXPECTED THROUGH SATURDAY AS SOUTHERLY
WINDS CONTINUE AHEAD OF AN APPROACHING COLD FRONT. THIS FRONT WILL
ALSO BRING INCREASING RAIN CHANCES...WITH THE THREAT FOR SHOWERS AND
THUNDERSTORMS BEGINNING TONIGHT...WITH MORE WIDESPREAD RAIN POSSIBLE
SATURDAY AFTERNOON. ADDITIONAL UPPER LEVEL DISTURBANCES BEHIND THIS
FRONT WILL KEEP THE THREAT FOR MORE SHOWERS GOING THROUGH SUNDAY.
QUIETER AND INCREASINGLY MILD CONDITIONS ARE EXPECTED HEADING
THROUGH NEXT WORK WEEK.

&&

.SHORT TERM...(THIS EVENING THROUGH TONIGHT)
ISSUED AT 359 PM EDT FRI SEP 19 2014

HIGH PRESSURE ADVANCING INTO NEW ENGLAND THIS AFTERNOON WITH STOUT
S/SW RETURN FLOW DEVELOPING ACROSS THE WESTERN GREAT LAKES. QUITE A
BIT OF SUNSHINE ACROSS LOWER MICHIGAN DOWN INTO THE OHIO VALLEY AND
MIDWEST THANKS TO WEDGE OF FAIRLY DRY AIR...WITH JUST SOME HIGH
CLOUDS DRIFTING THROUGH. THICKER CLOUD COVER HAS BEEN ACROSS THE
UPPER PENINSULA.

UPSTREAM...LOW AMPLITUDE SHORT WAVE IS ADVANCING EASTWARD ALONG THE
NORTH DAKOTA/CANADIAN BORDER WITH A WEAKER SFC LOW AND DEVELOPING
COLD FRONT MOVING THROUGH THE FAR NRN PLAINS. STRONG LOW LEVEL FLOW
(40 TO 50 KNOT H8 WINDS) AND A NARROW H8 THETA-E PLUME STRETCHES
FROM THE CENTRAL PLAINS INTO THE UPPER MIDWEST AND INTO ONTARIO. BUT
DESPITE THAT...AND SOME VERY STEEP MID LEVEL LAPSE RATES IN PLACE
FROM NEBRASKA INTO WISCONSIN...NOT MUCH HAPPENING IMMEDIATELY
UPSTREAM. JUST A NARROW BAND OF DECAYING SHOWERS MOVING THROUGH NRN
WISCONSIN ALONG THE EASTERN EDGE OF THE MOISTURE AXIS. ALL THE MAIN
PRECIP ACTION IS OCCURRING FROM CENTRAL MINNESOTA UP INTO ONTARIO
WHERE STRONGER FORCING AND DEEPER MOISTURE RESIDES.

TONIGHT...ANOTHER TOUGH CALL ON PRECIP EVOLUTION. H8 THETE-E AXIS
WILL FOLD INTO THE CWA LATE THIS EVENING AND THROUGH THE OVERNIGHT
HOURS...AND THERE MAY BE A FEW SHOWERS THAT WORK ACROSS THE NRN PART
OF THE CWA (STUFF COMING ACROSS THE WESTERN U.P. AND NRN WISCONSIN).
BETTER (DEEPER) MOISTURE AND STRONGER FORCING SLIDES THROUGH THE NRN
HALF OF THE CWA OVERNIGHT AND I BELIEVE THAT WILL BRING US OUR BEST
CHANCES FOR SHOWERS...ALTHOUGH GIVEN THE UPSTREAM TRENDS ACROSS
MINNESOTA CHANCES DON/T LOOK ALL THAT IMPRESSIVE UNLESS THINGS
REALLY RAMP UP THROUGH THE EVENING. HAVE TWEAKED PRECIP TIMING A BIT
TO HAVE LARGELY DRY CONDITIONS THIS EVENING WITH SOME SHOWERS
SNEAKING ACROSS THE NRN PART OF THE CWA. INCREASING CHANCES
OVERNIGHT FOR THE NRN/NW HALF OF THE CWA...AGAIN WHERE STRONGER
FORCING AND BETTER MOISTURE WILL BE.

THUNDER CHANCES...HARD TO IGNORE THE NARROW AXIS OF >7C/KM H7-H5
LAPSE RATES AND -1 TO -3C SHOWALTER INDICES SLIPPING THROUGH THE
REGION LATER TONIGHT ALTHOUGH ATMOSPHERE REMAINS A BIT CAPPED IN THE
MID LEVELS. BETTER CHANCES WILL PROBABLY RESIDE ACROSS THE NORTHERN
PART OF THE CWA WHERE DEEPER MOISTURE AND WEAKER CAPPING WILL
RESIDE. BUT IF WE DO GET ANY THUNDER...STRONG LOW-MID LEVEL FLOW
COULD BRING ABOUT ORGANIZED UPDRAFTS PRODUCING SOME HAIL AND GUSTY
WINDS.

.LONG TERM...(SATURDAY THROUGH FRIDAY)
ISSUED AT 359 PM EDT FRI SEP 19 2014

...STORMY START...WARM AND DRY FINISH...

HIGH IMPACT WEATHER POTENTIAL:

 *LOW RISK OF SEVERE THUNDERSTORMS /BEST CHANCES REMAIN DOWNSTATE/
  ON SATURDAY AFTERNOON.
 *FROST POTENTIAL MONDAY NIGHT.

PATTERN SUMMARY/FORECAST: A ROBUST PACIFIC JET WILL BE THE PRIMARY
GOVERNING FEATURE THROUGH THE LONG TERM FORECAST PERIOD...WHICH
INITIALLY WILL RE-ENERGIZE GULF OF ALASKA TROUGHING...THAT WILL CAUSE
DOWNSTREAM PATTERN AMPLIFICATION THAT WILL QUICKLY REINFORCE THE
EASTERN NOAM TROUGH THAT IS DAMPENING TODAY.  BEYOND THIS...THE GULF
OF ALASKA TROUGH LOOKS TO DEEPEN AND SPREAD EAST...ALLOWING
DOWNSTREAM LONGWAVE RIDGING TO BUILD EAST INTO CENTRAL AND EASTERN
NOAM BY THE MIDDLE AND LATTER PORTIONS OF NEXT WEEK.

PATTERN IMPLICATIONS: ACTIVE WEATHER TO START THE PERIOD AS THE
EASTERN TROUGH RELOADS IN THE PRESENCE OF MODEST
MOISTURE/INSTABILITY WITH A RETURN TO COOL/DRY CONDITIONS TO START
NEXT WEEK UNDER NORTHWEST FLOW ALOFT.  BEYOND THIS...GENERALLY DRY
CONDITIONS UNDER MODERATING TEMPERATURES AS THE WESTERN RIDGE BUILDS
EAST.

MODEL AGREEMENT/CONFIDENCE: STRONG GFS/GEFS/ECMWF/ECENS AGREEMENT IN THE
LARGE-SCALE PATTERN SUGGESTS ABOVE AVERAGE CONFIDENCE...PARTICULARLY
AT THE LATER TIME RANGES.

MIDDLE RANGE /SATURDAY THROUGH MONDAY/:

SATURDAY: CHALLENGING FORECAST RIGHT OFF THE BAT SATURDAY AS DEEP
MOISTURE PLUME FOLDS OVERHEAD COINCIDENT WITH AREA OF STEEP H8-7
LAPSE RATES.  HONESTLY NOT SURE THERE WILL BE MUCH ACTIVITY TO START
THE DAY WITH BEST MOISTURE ADVECTION AND LLJ FORCING WELL NORTH AND
EAST OF THE CWA.  EXPECT WE/LL SEE SOME SCATTERED SHOWERS IN THE
MOIST AIRMASS...WITH A RUMBLE OF THUNDER POSSIBLE AS WELL GIVEN
ELEVATED INSTABILITY.  MANY SPOTS COULD SEE A GOOD PORTION OF THE
MORNING REMAIN DRY.   BY AFTERNOON...A DIFFERENT STORY LOOKS TO
UNFOLD AS QG FORCING SPREADS OVER THE FORECAST AREA WITH SOME
SEMBLANCE OF RRQ JET FORCING SETTING UP NEAR...OR JUST SOUTH OF THE
FORECAST AREA.  AS THE FORCING FOR ASCENT ALOFT IMPROVES...THE
SURFACE COLD FRONT WILL ALSO BE ARRIVING FROM THE NORTH AND WEST.
FINALLY...THERE ARE SOME INDICATIONS THAT SOUTHERN AREAS HAVE A SHOT
OF SEEING SOME PEEKS OF SUNSHINE DURING THE MORNING HELPING BOOST
LLEVEL INSTABILITY.  ENVISION THE MORNING ISO-SCT SHRAS INCREASING
IN COVERAGE WITH THUNDER BECOMING MORE PROMINENT TO THE SOUTH.  THE
SEVERE THREAT IS NOT GREAT...BUT GIVEN ENOUGH INSTABILITY...THE MID
LEVEL WINDS SUPPORT A CONDITIONAL THREAT.  THE NEW SWODY2 KEEPS THE
SLIGHT RISK AREA JUST SOUTH OF OUR FORECAST AREA AND THIS LOOKS VERY
GOOD.  WILL CONTINUE MENTION OF THUNDER IN THE HWO...WITH THE
GREATEST CHANCE FOR A STRONG TO SEVERE STORM SOUTH OF M-55. LOCALLY
HEAVY RAIN WILL BE POSSIBLE WITH 10KFT WARM CLOUD DEPTHS AND SHEAR
PROFILES SUGGESTING ONLY MODEST STORM MOVEMENT.  QUITE A BIT WARMER
AND MORE HUMID THAN WE HAVE SEEN OF LATE...WITH HIGHS LIKELY POKING
ABOVE 70 /ESP NORTHEAST LOWER/ WITH DEWPOINTS RISING INTO THE 60S.

SATURDAY NIGHT: SURFACE COLD FRONT SINKS THROUGH THE FORECAST AREA
DURING THE EVENING HOURS...WITH ATTENTION TURNING TO IMPRESSIVE
VORT-MAX PROGGED TO AMPLIFY AS IT DIGS INTO THE DEVELOPING EASTERN
TROUGH.  THIS WILL SPREAD A NICE BULLSEYE OF QG FORCING FOR ASCENT
OVERHEAD OVERNIGHT.  EXPECT EVENING SHRA/TSRA ACTIVITY TO QUICKLY
WANE...WITH LIKELY A DRY PERIOD FOR MOST DURING THE LATE EVENING
BEFORE SHRAS REDEVELOP WITH THIS WAVE. WILL USE SCATTERED WORDING AT
THIS TIME...BUT WOULD NOT BE SURPRISED TO SEE POPS NEEDING TO BE
MOVED UPWARD AS THIS NEARS.  DESPITE DEVELOPING COOL ADVECTION...
OVERNIGHT LOWS WILL REMAIN ELEVATED WITH CLOUD COVER AND ASSOCIATED
PRECIPITATION /UPPER 40S EASTERN UPPER AND THEN LOW 50S OVER
NORTHERN LOWER/.

SUNDAY:  SHORTWAVE WILL BE OVERHEAD TO START THE MORNING AND PULL
EAST DURING THE DAY WITH VERY GRADUAL IMPROVEMENT EXPECTED.  EXPECT
SCATTERED SHRAS TO GENERALLY COME TO AN END BY EARLY
AFTERNOON...WITH LLEVEL MOISTURE BEING HARDER TO SCOUR OUT...AND
THUS ONLY PARTIAL CLEARING BY AFTERNOON /WITH MORE COMPLETE CLEARING
SUNDAY NIGHT/.  THIS AND CONTINUED COLD ADVECTION ALOFT WILL KEEP A
LID ON TEMPERATURES AND WILL STICK CLOSER TO MIXING TO H9...WHICH
YIELDS HIGHS GENERALLY IN THE UPPER 50S.  CLEARING SUNDAY NIGHT
SHOULD YIELD A MUCH CHILLIER NIGHT...WITH SOME RESIDUAL NORTHERLY
GRADIENT PRECLUDING TEMPS DROPPING TOO FAR OVER NORTHEAST LOWER.
WE/LL HAVE TO SEE HOW MUCH CLEARING OCCURS SUNDAY /AND THUS HOW MUCH
MIXING WE CAN ACCOMPLISH/...AS THERE COULD CERTAINLY BE SOME FROST
POTENTIAL.  WILL MENTION SUCH IN THE AFTERNOON HWO.

MONDAY:  MUCH QUIETER DAY EXPECTED ON MONDAY AS HIGH PRESSURE SOUTH
OF THE GREAT LAKES REGION WILL BE IN FIRM CONTROL OF THE WEATHER
ACROSS THE REGION.  STRONGLY BUILDING HEIGHTS ALOFT SUGGEST LIMITED
MIXING...SO DESPITE WHAT SHOULD BE PARTLY-MOSTLY SUNNY
SKIES...EXPECT TEMPERATURES ONLY AROUND 60.

LONG RANGE /TUESDAY THROUGH FRIDAY/:

THIS PERIOD IS SHAPING UP TO BE A BEAUTIFUL ONE WEATHER-WISE AS
EXPANSIVE AREA OF HIGH PRESSURE SETS UP OVER NEW ENGLAND WITH DRY
SOUTHEASTERLY/SOUTHERLY TRAJECTORIES ALONG WITH VERY SLOWLY WARMING
TEMPERATURES ALOFT AS UPPER RIDGING EDGES EAST.

H8 TEMPERATURES BUILD FROM AROUND 8C TO START THE PERIOD TO AROUND
11C TO END IT.  PATTERN RECOGNITION AND TIME OF YEAR SUGGESTS THAT
WE MAY NOT FULLY REALIZE MIXING TO THESE LEVELS...BUT HIGHS IN THE
LOWER /PERHAPS MIDDLE/ 70S CERTAINLY LOOK PLAUSIBLE /5-8F ABOVE
SEASONAL NORMS/ WHICH WILL SEEM THAT MUCH WARMER GIVEN THE RECENT
CHILL.  THE DRY AIRMASS ALSO PROMISES LARGE DIURNAL SWINGS WITH LOWS
GENERALLY IN THE 40S.

GFS/ECMWF BOTH WANDER REMNANTS OF CURRENT SOUTHWESTERN CONUS CUTOFF
LOW INTO THE MIDSECTION OF THE COUNTRY...WITH THIS POTENTIALLY
SERVING AS THE IMPETUS FOR SHRA DEVELOPMENT.  WHILE I CAN/T RULE OUT
THE POSSIBILITY OF A BRIEF SHRA OPPORTUNITY DURING THE SECOND HALF
OF THIS PERIOD...FEEL THAT THE FAR MORE LIKELY OUTCOME /GIVEN THE
UPPER LEVEL PATTERN/ IS THAT WE WILL REMAIN DRY THROUGH THE PERIOD
AND WILL CONTINUE TO MAINTAIN A DRY FORECAST.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 1145 PM EDT FRI SEP 19 2014

OVERALL CONDITIONS WILL REMAIN VFR OVERNIGHT DESPITE INCREASING
CLOUDS AND CHANCES OF SHOWERS. THUNDERSTORMS ARE ALSO POSSIBLE...
BUT THE CHANCE IS TOO SMALL TO INCLUDE IN THE TAF FOR NOW. CIGS
WILL LOWER TO MVFR ON SATURDAY WITH NMRS SHOWERS AND SCT
THUNDERSTORMS EXPECTED THRU MUCH OF THE DAY. LLWS WILL CONTINUE AT
ALL TAF SITES OVERNIGHT INTO EARLY MORNING.

&&

.MARINE...
ISSUED AT 410 PM EDT FRI SEP 19 2014

WINDS INCREASING NICELY THIS AFTERNOON WITH A TIGHTER PRESSURE
GRADIENT DEVELOPING ACROSS THE WESTERN GREAT LAKES. GUSTS ALREADY
PUSHING 30 KNOTS IN PARTS OF LAKE MICHIGAN INTO LAKE SUPERIOR AND
WILL INCREASE A BIT MORE AS WE GET INTO THE EVENING HOURS. GALE
WARNING WILL REMAIN FROM LEELANAU TO MANISTEE. GALE FORCE GUSTS
ALSO NOT OUT OF THE QUESTION FROM SEUL CHOIX TO THE BRIDGE
ALTHOUGH WE HAVE JUST SMALL CRAFT ADVISORIES UP THERE WITH GUSTS
TO 30 KNOTS IN THE FORECAST.

WINDS REMAIN GUSTY TONIGHT...SUBSIDE A LITTLE ON SATURDAY...BUT
FALL OFF MORE SATURDAY NIGHT INTO SUNDAY AND SHIFT INTO THE NORTH.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...SMALL CRAFT ADVISORY UNTIL 8 PM EDT SATURDAY FOR LHZ348-349.
LM...SMALL CRAFT ADVISORY UNTIL 5 AM EDT SUNDAY FOR LMZ323-341-342.
     GALE WARNING UNTIL 8 AM EDT SATURDAY FOR LMZ344>346.
LS...SMALL CRAFT ADVISORY UNTIL 8 AM EDT SATURDAY FOR LSZ321.

&&

$$

SYNOPSIS...TL
SHORT TERM...ADAM
LONG TERM...ARNOTT
AVIATION...MR
MARINE...ADAM





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