Area Forecast Discussion
Issued by NWS Gaylord, 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 KAPX 182301
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
601 PM EST TUE NOV 18 2014

.SYNOPSIS...
ISSUED AT 409 PM EST TUE NOV 18 2014

LAKE EFFECT SNOW WILL CONTINUE THIS EVENING. ANOTHER SYSTEM WILL
BRING LIGHT SNOW TO THE UPPER GREAT LAKES ON WEDNESDAY...AND MORE
LAKE EFFECT SNOW WILL FOLLOW BEHIND IT WEDNESDAY NIGHT INTO
THURSDAY. HOWEVER...TEMPERATURES WILL BECOME MILDER DURING THE
UPCOMING WEEKEND.

&&

.SHORT TERM...(THIS EVENING THROUGH TONIGHT)
ISSUED AT 409 PM EST TUE NOV 18 2014

...LAKE EFFECT SNOW SHOWERS CONTINUE TONIGHT WITH A SHIFTING FOCUS...

HIGH IMPACT WEATHER POTENTIAL: LAKE EFFECT SNOW SHOWERS SHIFTING
ORIENTATION TONIGHT...FOCUS FOR CONTINUED HEAVIER SNOWFALL ACROSS
THE TIP OF THE MITT COUNTIES.

PATTERN OVERVIEW/FORECAST: AFTERNOON SURFACE/COMPOSITE ANALYSIS
SHOWS MICHIGAN BETWEEN LOW PRESSURE TROUGH LYING ACROSS LAKE
HURON...AND A SURFACE RIDGE OVER THE MIDWEST.  DEEP LAYER THERMAL
TROUGH AXIS RUNS NORTHEAST-SOUTHWEST ACROSS LAKE HURON/LOWER
MICHIGAN...IMPRESSIVE -43C 500MB TEMPERATURE ON 12Z APX SOUNDING
(NEARLY 4 STANDARD DEVIATIONS BELOW THE MEAN FOR MID NOVEMBER WHICH
IS RECORD TERRITORY) LEADING TO INVERSION HEIGHTS ABOVE 500MB (SMALL
INVERSION AROUND 600MB ON 12Z APX SOUNDING).  WIDESPREAD MULTI-BAND
LAKE CONVECTION POURING IN OFF THE SURROUNDING LAKES WITHIN WEST-
NORTHWEST LOW LEVEL FLOW.  RADAR SNOWFALL ESTIMATES (USING 21:1
RATIOS) FOR THE SIX HOUR PERIOD ENDING 1930Z SUGGESTS A SMALL AREA
OF 5-10+ INCHES OF NEW SNOW CENTERED ALONG THE OTSEGO/CRAWFORD
COUNTY LINE...ANOTHER NARROW STRIPE OF HEAVIER SNOW STRETCHED FROM
LITTLE TRAVERSE BAY SOUTHEAST IN MONTMORENCY/SOUTHWEST ALPENA
COUNTIES OF 4-8 INCHES...AND SOME BANDS OF 1-2 INCH/6H AMOUNTS
OUTSIDE OF THOSE AREAS (ONLY RECENT OBSERVATION FROM EASTERN UPPER
OF 2 INCHES/6H AT THE SOO).  SO ABOUT AS NASTY AS ADVERTISED.

WATER VAPOR IMAGERY SHOWS A SHORT WAVE TROUGH DIGGING SOUTHEAST
TOWARD NORTH DAKOTA/MINNESOTA WHICH WILL ROTATE ITS WAY TOWARD THE
UPPER LAKES OVERNIGHT.  UPSTREAM RIDGE AXIS WILL ALSO PULL ACROSS
THE UPPER LAKES TONIGHT...WHICH WILL BACK WINDS AROUND TO A MORE
SOUTHERLY DIRECTION OVERNIGHT AS WELL AS ALLOW FLOW TO BECOME A
LITTLE MORE ANTICYCLONIC AND KICK IN SOME WARM ADVECTION.

PRIMARY FORECAST CONCERNS: EVOLUTION OF LAKE BANDS WITH SHIFTING
WINDS.

TONIGHT: SHIFTING WINDS EXPECTED TO TURN BAND ORIENTATION
COUNTERCLOCKWISE STARTING EARLY EVENING...ALREADY SEEING SIGNS OF
THIS OCCURRING IN SATELLITE LOOP TRENDS (RATHER DRAMATICALLY OVER
LAKE SUPERIOR).  ONSET OF WARM ADVECTION ACTING IN CONCERT WITH
LARGER SCALE QG SUBSIDENCE WILL BEGIN TO PULL INVERSION HEIGHTS
DOWN...BUT STILL THINK THERE WILL BE A FOCUS FOR HEAVIER SNOWFALL
SHIFTING NORTH OF THE M-32 CORRIDOR THOUGH SNOWFALL POTENTIAL WILL
GET SPREAD OUT DUE TO CHANGING BAND ORIENTATION/ADVECTION.  HAVE
PAINTED IN A SWATH OF 3-6 INCHES ACROSS CHARLEVOIX/EMMET/CHEBOYGAN/
FAR WESTERN PRESQUE ISLE COUNTY FOR TONIGHT...WITH WINTER STORM
WARNING ALREADY HAVING BEEN EXTENDED THROUGH TONIGHT TO COVER THIS.
SNOW SHOWERS ACROSS EASTERN UPPER EXPECTED TO WANE LATER THIS
EVENING AS WINDS SHIFT OFFSHORE FROM LAKE SUPERIOR...BUT SHOULD MAKE
A RETURN AFTER MIDNIGHT INTO MACKINAC/FAR SOUTHEAST CHIPPEWA
COUNTIES AS LOW LEVEL FLOW BECOMES SOUTHWESTERLY.  DON`T SEE ANY
NEED TO MAKE CHANGES TO CURRENT HEADLINES...STILL SNOWING ALONG M-32
PORTION OF WINTER STORM WARNING AND THIS RUNS THROUGH MIDNIGHT (AS
DOES CHIPPEWA COUNTY ADVISORY) SO THAT SHOULD COVER CONTINUED
ACTIVITY WITH AN EXPECTED TAPERING OFF AS THE EVENING PROGRESSES.
REMAINING ADVISORIES SET TO EXPIRE AT 00Z AND THAT SEEMS
REASONABLE...WILL ALSO ALLOW A CHANCE TO "RESET" THINGS SINCE WE MAY
NEED A NEW ROUND OF HEADLINES FOR LAKE ENHANCED SNOWFALL NEAR LAKE
MICHIGAN FOR WEDNESDAY.

.LONG TERM...(WEDNESDAY THROUGH TUESDAY)
ISSUED AT 409 PM EST TUE NOV 18 2014

WEDNESDAY THROUGH FRIDAY: WARM ADVECTION AHEAD OF A COLD FRONT
ASSOCIATED WITH A LOW PRESSURE SYSTEM OVER THE NORTHERN GREAT
LAKES REGION WILL BEGIN TO OVERSPREAD NORTHERN MICHIGAN WITH SNOW
DURING THE MORNING HOURS...LOOKING AT 2 TO 4 INCHES FOR THE
MAJORITY OF THE CWA...WITH NORTHWEST LOWER CLOSER TO THE 4 INCHES
AND NORTHEAST CLOSER TO 2 INCHES. LAKE EFFECT/ENHANCED SNOWS WILL
BE LIMITED TO MOSTLY EASTERN UPPER WEST OF THE MACKINAC BRIDGE AND
WESTERN PORTIONS OF MANISTEE...BENZIE...AND LEELANAU COUNTIES
DURING THE DAYTIME HOURS AS WINDS BACK TO NEARLY DUE SOUTHERLY IN
RESPONSE TO THE SHORTWAVE TROUGH TILTING NEGATIVELY. IN RESPONSE
THERE IS SOME HINTS OF A STRONG CONVERGENT BAND FORMING OVER MID-
LAKE MICHIGAN WHICH MAY CLIP PARTS OF MANISTEE...BENZIE...AND
LEELANAU COUNTIES AS IT BEGINS TO PUSH EASTWARD WITH THE COLD
FRONT...BUT WILL DEFINITELY DRIVE SOME HEAVIER ENHANCED SNOWS INTO
WESTERN MACKINAC COUNTY...IMPACTING THE US-2 CORRIDOR. THESE PARTS
SEEING THE HEAVIER SNOW WILL MOST LIKELY SEE A 4 TO 6 INCH RANGE
WITH LOCALLY HEAVIER AMOUNTS POSSIBLE DURING THE DAY WEDNESDAY.

THE COLD FRONT APPEARS TO BE POISED TO MOVE THROUGH NORTHERN
MICHIGAN DURING THE EVENING HOURS...RETURNING LAKE EFFECT SNOWS TO
NORTHWEST LOWER AND EASTERN UPPER MICHIGAN ONCE AGAIN. THE SAME
AREAS THAT HAVE BEEN HIT WITH OVER A FOOT OF SNOW LAST NIGHT AND
TODAY WILL BE THE AREAS HIT WITH THE HEAVIEST SNOWS YET AGAIN. DELTA
T/S WILL STILL BE AT OR ABOVE 20C...WITH PERSISTENT WESTERLY WINDS
THROUGH THURSDAY EVENING...WHEN THEY WILL FINALLY BEGIN TO VEER JUST
A BIT MORE WEST-NORTHWESTERLY...BUT STILL CONTINUE TO PRODUCE LAKE
EFFECT SNOW FOR NORTHWESTERN LOWER AND EASTERN UPPER MICHIGAN. WITH
OMEGA MAXIMIZED ONCE AGAIN IN THE DGZ ALONG WITH DEEP MOISTURE...
THE FAVORED WEST-NORTHWESTERLY LAKE EFFECT WIND REGIMES MAY SEE
TOTALS FROM WEDNESDAY NIGHT THROUGH LATE FRIDAY MORNING/EARLY FRIDAY
AFTERNOON CLIMB TO ABOVE A FOOT OF SNOW YET AGAIN. HEADLINES WILL OF
COURSE NEED TO BE ISSUED AHEAD OF THIS STORM.

HIGH PRESSURE BEGINS TO BUILD OVER THE EASTERN UNITED STATES
BRINGING MUCH DRIER AIR AND AN END TO ANY LINGERING LAKE EFFECT
SNOWS BY LATE AFTERNOON FRIDAY. UPPER LEVEL RIDGE BEGINS TO INCREASE
HEIGHTS ACROSS THE GREAT LAKES REGION SETTING THE STAGE FOR A BIT OF
A WARM UP...AT LEAST TO WHAT IS NORMAL FOR THIS TIME OF THE YEAR...
IN THE EXTENDED PERIOD TIME FRAME. TEMPERATURES WILL REMAIN BELOW
NORMAL FOR THURSDAY AND FRIDAY...ONLY REACHING INTO THE LOW TO MID
20S AND LOWS DROPPING INTO THE LOW TEENS THURSDAY AND FRIDAY
MORNINGS.

TJL

EXTENDED FORECAST (SATURDAY THROUGH TUESDAY): (11/22)SATURDAY...
THE 0C 850 MB LINE IS RUNNING THROUGH THE FORECAST AREA IN THE
MORNING. BY 00Z IT IS THROUGH E UPPER. IT WOULD LOOK LIKE LIGHT
SNOW IN E UPPER AND A MIX/CHANGING TO RAIN IN N LOWER. SFC
TEMPERATURES REMAIN ABOVE FREEZING SO WILL GO WITH ALL RAIN
EVERYWHERE OVERNIGHT. (11/23)SUNDAY...THE SFC LOW THAT DEVELOPS
BEHIND THE WARM AIR MOVES FROM THE SOUTHERN PLAINS TO THE UPPER
GREAT LAKES BY 00Z. RAIN IS LIKELY/DEFINITE ACROSS THE FORECAST
AREA THROUGH THE NIGHT. (11/24)MONDAY...THE LOW MOVES FROM THE
UPPER GREAT LAKES TO QUEBEC AND THE COLD AIR BEGINS TO MOVE IN. IT
LOOKS COLD ENOUGH TO MIX IN E UPPER, AND REMAIN RAIN IN N LOWER.
(11/25)TUESDAY...THE COLD AIR IS INTO THE REGION AND IT LOOKS LIKE
A CHANCE OF SNOW AS ANOTHER 500 MB LOW SWINGS INTO THE UPPER GREAT
LAKES.

JSL

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 600 PM EST TUE NOV 18 2014

W/NW FLOW LAKE EFFECT SNOW SHOWERS WILL GRADUALLY SHIFT NORTHWARD
TO TARGET THE TIP OF THE MITT AND THE STRAITS AS LOW LEVEL WINDS
BACK TO THE SW BY DAYBREAK WEDNESDAY. ANOTHER AREA OF LOW PRESSURE
WILL LIFT INTO THE GREAT LAKES REGION ON WEDNESDAY...PRODUCING
ANOTHER WAVE OF SYNOPTICALLY DRIVEN SNOW FOR ALL OF NRN LWR
MICHIGAN...AND SERVING TO ENHANCE ONGOING SW FLOW LAKE EFFECT SNOW
SHOWERS IMPACTING PORTIONS OF NW LWR MICHIGAN AND THE STRAITS.
OVERALL CONDITIONS WITHIN ANY SNOW SHOWERS WILL REMAIN MVFR/IFR...
WITH MAINLY VFR CONDITIONS AWAY FROM SNOW SHOWER ACTIVITY. GUSTY WEST
WINDS WILL DIMINISH TO AROUND 10 KTS THIS EVENING...AND THEN SHIFT
TO THE S/SW LATE TONIGHT AND TO THE S/SE ON WEDNESDAY.

&&

.MARINE...
ISSUED AT 409 PM EST TUE NOV 18 2014

SMALL CRAFT CRITERIA WINDS WILL CONTINUE THROUGH WEDNESDAY
MORNING AS THE CURRENT STORM SYSTEM CONTINUES IT/S PUSH TOWARDS
THE NORTHEAST. ANOTHER STORM SYSTEM WILL APPROACH FROM THE
NORTHERN PLAINS RENEWING THE CHANCES OF WINDS NEARING GALE WARNING
CRITERIA OVER THE NEARSHORE WATERS OF LAKE MICHIGAN THURSDAY
MORNING AND AFTERNOON HOURS...BUT WITH THE GREATEST CHANCE OF GALE
WINDS BEING ALONG THE NEARSHORE WATERS OF LAKE HURON WITH NO LAND
IMPEDING THE SOUTHWESTERLY WINDS AHEAD OF THE APPROACHING COLD
FRONT. THESE WINDS SHOULD DIMINISH DURING THE EVENING HOURS OF
THURSDAY AFTER THE AFOREMENTIONED COLD FRONT DEPARTS ALTHOUGH
WEST-NORTHWESTERLY WINDS BEHIND THE FRONT WILL STILL GUST TO
SMALL CRAFT ADVISORY CRITERIA. EXPECT PERIODS OF HEAVY LAKE
EFFECT SNOWS...REDUCING VISIBILITIES TO NEAR ZERO AT TIMES THROUGH
THURSDAY EVENING.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR MIZ015-
     020-024>029-031>033.

     WINTER STORM WARNING UNTIL MIDNIGHT EST TONIGHT FOR MIZ021>023.

     WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR MIZ008.

     WINTER STORM WARNING UNTIL 5 AM EST WEDNESDAY FOR MIZ016>019.

LH...SMALL CRAFT ADVISORY UNTIL 5 AM EST WEDNESDAY FOR LHZ345-347>349.

LM...SMALL CRAFT ADVISORY UNTIL 5 AM EST WEDNESDAY FOR LMZ341-342-
     344>346.

LS...SMALL CRAFT ADVISORY UNTIL 5 AM EST WEDNESDAY FOR LSZ321.

&&

$$

SYNOPSIS...JSL
SHORT TERM...JPB
LONG TERM...TJL
AVIATION...MLR
MARINE...TJL


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