Area Forecast Discussion
Issued by NWS Gaylord, MI

Home | Current Version | Previous Version | Text Only | 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 151746
AFDAPX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
1246 PM EST MON DEC 15 2014

.UPDATE...
ISSUED AT 1140 AM EST MON DEC 15 2014

13Z SURFACE ANALYSIS SHOWS 999MB LOW CENTERED OVER NORTHEAST
KANSAS...ASSOCIATED WITH A COMPACT UPPER LOW IN THE SAME VICINITY.
NORTHWARD EXTENDING BAROCLINIC ZONE ACROSS NORTHWEST IOWA/SOUTHEAST
MINNESOTA/NORTHWEST WISCONSIN AND UP AND AROUND THE NORTH SIDE OF
LAKE SUPERIOR.  TRAPPED LOW CLOUDS ACROSS NORTHERN MICHIGAN THIS
MORNING ALONG WITH A GOOD DEAL OF FOG...STILL PRETTY THICK ACROSS
EASTERN UPPER AND INTERIOR NORTHERN LOWER.  SOME SPITS OF RADAR
RETURNS ACROSS LAKE MICHIGAN/STRAITS REGION...DEEPER MOISTURE NOTED
ON 12Z GRB SOUNDING LIKELY SQUEEZING OUT SOME DRIZZLE.

HAVE EXTENDED DENSE FOG ADVISORY TO 00Z FOR EASTERN UPPER/INTERIOR
NORTHERN LOWER...INSTEAD OF TRYING TO PIECEMEAL DIFFERENT ENDING
TIMES JUST EXTENDED IT THE SAME AMOUNT OF TIME EVERYWHERE AND WILL
CHUNK OFF PIECES OF THE ADVISORY AS CONDITIONS IMPROVE.

&&

.NEAR TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 342 AM EST MON DEC 15 2014

HIGH IMPACT WEATHER POTENTIAL: FOG

FORECAST CHALLENGES: FOG VISIBILITY

OVERVIEW...SOUNDING LIKE A BROKEN RECORD FOR THE 3RD NIGHT AS THE
SFC HIGH IN THE OHIO VALLEY AND THE SFC LOW IN THE SOUTHERN PLAINS
COMBINE TO PRODUCE MILD, MOIST FLOW INTO THE UPPER GREAT LAKES UNDER
THE 500 MB RIDGE. THE PATTERN HAS BEEN RATHER STATIONARY OVER THE
LAST FEW DAYS AS A SLOWLY MOVING 500 MB LOW HAS MOVED FROM THE WEST
COAST INTO THE SOUTHERN PLAINS, WHILE A 500 MB HIGH HAS BEEN CAMPED
OUT ALONG THE CANADIAN PAC COAST. COUPLE THAT WITH THE 500 MB LOW
ROTATING OFF OF NEW ENGLAND/CANADIAN MARITIMES THAT HAS SLOWED THE
PATTERN DOWN.

TODAY...THE MAIN CONCERN WILL CONTINUE TO BE THE MOISTURE TRAPPED
BENEATH CAPPING INVERSION THAT HAS BEEN CONTINUING TO PRODUCE FOG
AND DRIZZLE. HOWEVER, IT LOOKS LIKE THAT THE PATTERN THAT PRODUCED
THE CAPPING INVERSION WILL BEGIN TO MOVE AS THE 500 MB TROUGH IN THE
SOUTHERN PLAINS BEGINS TO PHASE WITH THE NORTHERN BRANCH FEATURE,
HELPING TO KICK THE PATTERN IN TO GEAR. IN THE MEANTIME, THE SFC
FEATURE THAT HAS DEVELOPED ALONG THE 500 MB TROUGH WILL MOVE INTO
THE UPPER GREAT LAKES TODAY WITH A WEAKER LEADING WAVE MOVING INTO
LAKE SUPERIOR AND POSSIBLY INTO ONTARIO BY 00Z. THIS HELPS TO DEEPEN
THE MOISTURE WHICH HAS BEEN HAVING TROUBLE REACHING THE -10C LEVEL
SO THAT THE SEEDER/FEEDER PROCESSES CAN BEGIN TO GET SOMETHING OTHER
THAN DRIZZLE GOING.

IT LOOKS LIKE THAT THE MOISTURE MAY SLOWLY DEEPEN DURING THE LATE
AFTERNOON, SO THAT THE DRIZZLE AND LOW CLOUDS MAY BEGIN TO BREAK UP
A BIT MAINLY SOUTH OF M-72.

TONIGHT...THINGS BEGIN TO CHANGE DURING THE EVENING AS THE MODELS
ARE SHOWING ENOUGH MOISTURE IN THE ENTIRE COLUMN SO THAT RAIN IS
MORE LIKELY. THE 700-500 MB LAYER RH INCREASES FROM THE <20% PRE-18Z
TO WELL OVER 70% BY 06Z. IT LOOKS LIKE THE MOISTURE WILL TAKE ITS
TIME THROUGH THE EVENING, ESPECIALLY ALONG THE EASTERN PORTIONS OF
THE M-72 AND M-55 CORRIDORS AS THE 500MB TROUGH ENTERING LAKE
SUPERIOR WILL PUSH ITS MOISTURE INTO N LOWER BEFORE THE SOUTHERN
ENERGY DOES. HOWEVER, BY THE TIME WE GET TO 12Z THE MOISTURE AND THE
500 MB TROUGHS ARE MOVING INTO THE UPPER GREAT LAKES, SO THAT LIGHT
RAIN SHOULD BE THE RESULT.

&&

.SHORT TERM...(TUESDAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 342 AM EST MON DEC 15 2014

HIGH IMPACT WEATHER POTENTIAL...SNOW ACCUMS IN THE SNOWBELTS TUE
NIGHT/WED...ESPECIALLY IN EASTERN UPPER.

WE WILL TRANSITION TO SOMETHING THAT AT LEAST VAGUELY RESEMBLES
WINTER...FOR A COUPLE OF DAYS ANYWAY. DECAYING SOUTHERN STREAM UPPER
TROF WILL CROSS LOWER MI ON TUESDAY. DIGGING NORTHERN STREAM UPPER
LOW WILL REACH THE MN ARROWHEAD TUE EVENING...AND CROSS NORTHERN
LOWER MI WED AFTERNOON. THE ASSOCIATED SURFACE LOW WILL CROSS FAR
SOUTHERN LOWER MI TUE MORNING...THEN SLOWLY MOVE DOWN THE EASTERN
LAKES AND ST LAWRENCE VALLEY THRU WED. SHARP SURFACE TROFFING WILL
LINGER BACK INTO EASTERN UPPER MI AND/OR THE STRAITS REGION.
SYNOPTIC PRECIP WILL BE SEEN TUESDAY...GIVING WAY TO LAKE EFFECT
AND/OR LAKE ENHANCED TUE NIGHT-WED. PRECIP TRENDS ARE THE MAIN
CONCERN.

TUESDAY...PRECIP WILL BE WIDESPREAD IN THE MORNING HOURS. SOME
INDICATIONS OF SW-NE ORIENTED FGEN BAND OVER NORTHERN LOWER MI...AS
THE LOW PASSES TO OUR SOUTH. THIS RESULTS IN STRONGER FORCING
PRESENT THAN HAD BEEN EARLIER ANTICIPATED. SAID FORCING WANES DURING
THE AFTERNOON...AND PRECIP WILL DIMINISH WITH TIME (ESPECIALLY IN
WESTERN SECTIONS). BUT VERY HIGH POPS STILL IN ORDER IN THE PM.
TOTAL QPF VALUES AVERAGE AROUND QUARTER-INCH. COMPARED TO 24 HOURS
AGO...MODELS ARE MUCH SLOWER TO BRING IN COOL AIR AT THE SURFACE.
THIS IS ESPECIALLY THE CASE IN EASTERN UPPER...WHERE BAGGINESS IN
THE MSLP FIELD RESULTS IN MINIMAL WINDS AND THUS COLD ADVECTION IN
THE PM. COULD SEE A MIX IN FAR WESTERN CHIP/MACK VERY LATE...
OTHERWISE PRECIP WILL BE MOSTLY LIQUID. A LITTLE MORE EMPHATIC PUSH
OF LOW-LEVEL COLD AIR ARRIVES IN NW LOWER MI IN THE AFTERNOON. MODEL
SOUNDINGS SUPPORT PLACES W OF I-75 MIXING AND TURNING TO SNOW DURING
THE PM. AGAIN...PRECIP WILL BE DIMINISHING WITH TIME AS WELL...SO
ANY ACCUMS WILL BE NEGLIGIBLE.

MAX TEMPS MAINLY WITHIN A FEW DEGREES OF 40F...WITH FALLING READINGS
IN NW LOWER IN THE AFTERNOON.

TUE NIGHT/WED...THE NORTHERN STREAM UPPER LOW PIVOTS SOUTH NEAR THE
WEST TIP OF SUPERIOR...THEN EAST ACROSS SOUTHERN SECTIONS OF THE
FORECAST AREA. DEEPER MOISTURE WILL BE FOUND LEFT OF THE PATH OF THE
500MB AND 700MB LOWS...WHILE MUCH DRIER MID-LEVEL AIR FLOODS AREAS
NEAR AND SOUTH OF THIS TRACK. THE LATTER ALSO CORRESPONDS TO THE
STRONGEST PUSH OF COLD AIR...WITH 850MB TEMPS TO -14/-15C ON WED.
THIS MEANS THAT THE MOST FAVORABLE LAKE EFFECT PARAMETERS NEVER
QUITE LINE UP...WITH NORTHERN LOWER MI SEEING THE MOST INSTABILITY
BUT THE LEAST MOISTURE...WHILE WE FLIP THAT SCRIPT IN EASTERN UPPER.

PRECIP WILL STILL BE MIXY IN EASTERN SECTIONS IN THE EVENING HOURS
TUESDAY...BEFORE GOING TO ALL SNOW. WILL PAINT A RELATIVELY BROAD 1-
3 INCHES IN NW AND N CENTRAL LOWER TUE NIGHT...WITH A PURER LAKE
EFFECT EVENT THAT STARTS WITH A NNW FETCH AND GRADUALLY BACKS WNW.
EASTERN UPPER WILL SEE STEADIER SYNOPTIC PRECIP...WITH SOME LAKE
ENHANCEMENT VERY LATE AS COLDER AIR FINALLY PUNCHES IN AT 900MB. 2-4
INCHES PROGGED THERE.

ON WEDNESDAY...SYNOPTIC SUPPORT WANES THRU THE DAY AS NORTHERN
STREAM 500MB LOW MOVES THRU AND EAST. HOWEVER...INSTABILITY REMAINS
CONSIDERABLE...AND LAKE EFFECT WILL MAINTAIN ITSELF. SOMETHING ON
THE ORDER TO 1-3 INCHES EAST OF GD TRAV AND LTL TRAV BAYS...AND IN
EASTERN UPPER MI...LOOKS REASONABLE.

MIN TEMPS IN THE 20S. MAX TEMPS UPPER 20S TO NEAR 30F.

&&

.LONG TERM...(THURSDAY THROUGH SUNDAY)
ISSUED AT 342 AM EST MON DEC 15 2014

LAKE EFFECT SNOW WILL DIMINISH WED NIGHT/THU AS THE CORE OF COLD AIR
MOVES OFF TO THE EAST. LARGE HIGH PRESSURE BUILDS IN FROM THE WEST
TO DRY US OUT FRI-SAT. THE NEXT SOUTHERN STREAM SYSTEM WILL TRACK
FROM THE DEEP SOUTH TO MID ATLANTIC STATES THIS WEEKEND...AND STILL
SEEMS MOST LIKELY TO MISS US TO THE SOUTH. TEMPS WILL BE NEAR TO
PERHAPS A SMIDGE ABOVE CLIMO.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1245 PM EST MON DEC 15 2014

PREVAILING IFR EXPECTED THROUGH TONIGHT AS LOW CLOUDS AND FOG
PERSIST...THOUGH VISIBILITIES MAY IMPROVE A LTITLE WITH ONSET OF
RAINFALL THIS EVENING.

&&

.MARINE...
ISSUED AT 342 AM EST MON DEC 15 2014

DENSE FOG WILL CONTINUE TO BE AN ISSUE THROUGH THE DAY AS
THE MOISTURE CONTINUES OVER THE UPPER GREAT LAKES. WINDS WILL
CONTINUE TO BE VARIABLE, MAINLY UNDER 10 KNOTS AS THE GRADIENT
REMAINS WEAK THROUGH MOST OF THE DAY. THE SFC LOW WILL MOVE INTO S
LAKE MICHIGAN BETWEEN 06Z AND 12Z CONTINUING THE WEAK GRADIENT.
HOWEVER, TUESDAY, THE SFC LOW MOVES ACROSS S LOWER MICHIGAN AND THE
GRADIENT TIGHTENS BEHIND THE LOW SO THAT SMALL CRAFT WINDS AND WAVES
WILL BE EXPECTED THROUGH THE DAY AND INTO THE NIGHT. THE WINDS AND
WAVES WILL BEGIN TO BUILD IN LAKE HURON TUESDAY NIGHT AS THE
GRADIENT AND WIND FETCHES BEGIN TO TURN MORE NORTHWEST.

&&

.APX WATCHES/WARNINGS/ADVISORIES...
MI...DENSE FOG ADVISORY UNTIL 7 PM EST THIS EVENING FOR MIZ008-
     015>017-019-021>023-027>030-032>035.

LH...NONE.
LM...NONE.
LS...NONE.
&&

$$

UPDATE...JPB
SHORT TERM...JAZ
SHORT TERM...JAZ
LONG TERM...JAZ
MARINE...JSL


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