Area Forecast Discussion
Issued by NWS Marquette, MI

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
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 KMQT 232000
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
300 PM EST TUE DEC 23 2014

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 259 PM EST TUE DEC 23 2014

UPPER AIR PATTERN CONSISTS OF A CLOSED 500 MB LOW OVER EASTERN IOWA
THIS MORNING. THE NAM TAKES THE CLOSED 500 MB LOW NORTHEAST TODAY
AND ACROSS THE U.P. THIS AFTERNOON. A 500 MB TROUGH REMAINS OVER THE
AREA THROUGH WED. NAM SHOWS A NEW 500 MB CLOSED LOW FORMING IN THIS
TROUGH OVER SW MISSOURI 12Z WED THAT HEADS NORTHEAST TO SOUTHERN
LAKE MICHIGAN BY 00Z THU.

NAM...GFS AND ECMWF SHOW STRONG 850-500 MB Q-VECTOR CONVERGENCE THIS
AFTERNOON MOVING OUT OF THE CWA BY THIS EVENING. ALL MODELS TRY TO
SHOW SOME Q-VECTOR CONVERGENCE RETURNING TO THE EASTERN CWA BY 00Z
THU. GFS IS THE FURTHEST NORTH WITH THIS SECOND SYSTEM WITH THE
NAM...ECMWF AND CANADIAN FURTHER SOUTH WITH THE SFC LOW OVER
SOUTHERN LOWER MICHIGAN WITH THE GFS HAVING THE LOW OVER NORTHERN
LOWER MICHIGAN. GFS IS THE ONLY MODEL THAT FAR NORTH AND WEST WITH
THE HEAVIEST PCPN AND DID NOT USE. 12Z ECMWF CAME UP FURTHER EAST
WITH NEXT STORM...SO AFTER THE SNOW WINDS DOWN THIS
AFTERNOON...LIGHT SNOW...DRIZZLE...FREEZING DRIZZLE WILL CONTINUE
OVERNIGHT. DID NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST FOR
TEMPERATURES. HEAVIEST SNOW HAS MOVED OUT AND CUT BACK POPS THIS
AFTERNOON. DID KEEP HIGHEST POPS IN THE NORTHERLY LAKE EFFECT SNOW
BELTS WITH SOME LAKE ENHANCEMENT AND UPSLOPE HELPING TO AID IN THE
SNOW AND KEPT HEAVIER AMOUNTS OF QPF IN. MIXED PCPN OF RAIN AND SNOW
WILL CONTINUE ACROSS THE SOUTHERN AND EASTERN CWA TONIGHT AND ALSO
FOR WED. OVERALL...ONLY MAJOR CHANGE WAS TO SPEED UP DIMINISHING
POPS THIS AFTERNOON AND EVENING AND DID NOT CHANGE PCPN TYPES.

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 503 AM EST TUE DEC 23 2014

FOLLOWED THE ECMWF/GEM FOR THE TRACK OF THE LOW PRESSURE SYSTEM
LIFTING JUST EAST OF LOWER MICHIGAN WEDNESDAY AFTN INTO CHIRSTMAS
EVE. GIVEN THE STRENGTH OF THE JET STREAK UP TO 180 KTS OVER THE
INTERMOUNTAIN WEST AND COULPLE OF STRONGER SHORTWAVES DIGGING INTO
THE BASE OF CNTRL PLAINS TROUGH...THINK GFS AND PARALLEL GFS MODELS
ARE TOO QUICK TO BRING THE SHORTWAVE NORTH TO MICHIGAN ON WEDNESDAY
WHICH ALSO PUSHES THE LOW FARTHER TO THE WEST COMPARED TO OTHER
MODELS. 00Z NAM WAS ON THE SLOWER SIDE BUT WOULD TEND TO BUY THAT
IDEA GIVEN HOW FAR SOUTH THIS WAVE WILL INITIALLY DIG INTO TX BEFORE
LIFTING BACK TO THE NORTH. ESSENTIALLY ECMWF/GEM AND NAM IDEAS KEEP
BULK OF DEFORMATION PRECIP JUST NORTHWEST OF SFC-H85 LOWS...MAINLY
IN THE FORM OF SNOW...JUST EAST OF THE CWA. FOR THE POPS/QPF/SNOW
FOLLOWED CLOSELY TO THE WPC GUIDANCE WHICH RESULTED IN CATEGORICAL
POPS FOR LUCE COUNTY LATE WEDNESDAY AFTN INTO CHRISTMAS EVE. HIGH
POPS TAPER QUICKLY TO THE WEST MORE INTO THE CENTRAL CWA.

FOR MOST OF THE CWA ON WEDNESDAY...MAIN CONCERN WILL BE LINGERING
LGT SNOW IN WAKE OF THE SYSTEM MOVING THROUGH TODAY. SOUNDINGS STILL
SHOWING DZ/FZDZ SIGNAL AS WELL WITH MOISTURE UP TO AROUND -7C AND
DRYING ABOVE. HIT THE SNOW AND DRIZZLE CHANCES HARDEST WHERE
NORTHERLY WINDS PROVIDE ADDITIONAL UPSLOPE LIFTING...SO MAINLY OVER
PORTIONS OF WEST AND NCNTRL UPR MICHIGAN. PASSAGE OF WEAK NORTHERN
STREAM WAVE WITH DEEPER MOISTURE LIKELY ENDS THE FZDZ/DZ REGIME BY
CHRISTMAS EVE EVENING. AS LONG AS LOW PRESSURE SYSTEM OVER CNTRL
GREAT LAKES DOES NOT COME ANY FARTHER WEST...WILL SEE ANY LGT SNOW
TAPERING OFF BY MIDNIGHT FOR FAR EAST. TOTAL SNOW ACCUMS AS IT
STANDS NOW COULD BE A FEW INCHES TOWARD KERY. THIS IDEA MATCHES WPC
SNOW FORECASTS FAIRLY WELL. TEMPS THROUGOUT THE WED-WED NIGHT TIME
FRAME REMAIN MILD WITH LOW TO MID 30S ON WED AND UPR 20S TO LOW 30S
WED NIGHT.

ON CHRISTMAS DAY...A COOLISH AIRMASS ALOFT /H85 TEMPS -10C/ IN WAKE
OF THE NORTHERN STREAM TROUGH MAY RESULT IN WEAK LAKE ENHANCED SNOW
FOR WNW FLOW AREAS...BUT OTHERWISE APPEARS TO BE A QUIET DAY WITH
CONTINUED ABOVE NORMAL TEMPS IN THE LOW-MID 30S. TIGHTER PRESSURE
GRADIENT ON WEST EDGE OF DEEPENING LOW LIFTING TOWARD JAMES BAY MAY
LEAD TO SOME GUSTY WINDS AND BLSN OVER FAR EAST CWA TO START THE
DAY...BUT THIS SHOULD EASE QUICKLY.

ON TO THE NEXT SYSTEM THAT COULD IMPACT THE UPPER GREAT LAKES. TREND
OF DEEPER/SLOWER SHORTWAVE TROUGH OVER CNTRL CONUS BY FRIDAY IS
EMERGING. RESULT IS MORE DEVELOPED SFC LOW PRESSURE SYSTEM AND AREA
OF LGT TO MODERATE SNOW ORIENTED SW-NE ON NORTHWEST SIDE OF H85 LOW.
MIXING RATIOS INTO THE SYSTEM A SHADE OVER 2 G/KG AND SLR/S WILL BE
HIGHER AS COLDER AIR WILL HAVE WORKED FM THE NORTHERN PLAINS TO THE
UPPER GREAT LAKES. OVERALL A SWATH OF MODERATE SNOW MAY OCCUR...
PEGGED TO MAINLY IMPACT WESTERN SECTIONS OF UPR MICHIGAN FRIDAY
AFTN/FRIDAY NIGHT. ONSHORE FLOW AND TEMPS COLD ENOUGH COULD LEAD TO
LAKE ENHANCEMENT OVER WESTERN TIER OF UPR MICHIGAN FOR AREAS FAVORED
BY NW WINDS. WILL CONTINUE TO MENTION IN THE HWO.

LAKE EFFECT LIKELY IN THE WAKE OF THIS SYSTEM AS TEMPS CONTINUE TO
COOL WITH READINGS BLO -15C BY LATE IN THE WEEKEND. BLYR DRYING OUT
AND INCREASING SFC RIDGING WILL LIKELY PUT CRIMP INTO THE LES. KEPT
POPS SIMILAR TO PREVIOUS FORECAST FOR THE WEEKEND...WITH LIKELY POPS
IN THE NW FLOW AREAS NEAR LK SUPERIOR. AFTER THE MILD DAYTIME TEMPS
THIS WEEK...THE COOLING TEMPS WILL BE NOTICABLE WITH READINGS ONLY
IN THE TEENS TO LOWER 20S BY SUNDAY.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1220 PM EST TUE DEC 23 2014

EXPECT LIFR/VLIFR CONDITIONS TO PREDOMINATE THIS FCST PERIOD AT ALL
3 TAF SITES. GUSTY ENE WINDS MAY CAUSE ENUF BLSN AT THE EXPOSED CMX
LOCATION TO CAUSE VSBYS THERE TO FALL TOWARD VLIFR AS
WELL...ESPECIALLY IN THE EARLY AFTN WHEN STRONGER DYNAMIC FORCING WL
IMPACT THAT LOCATION. THE DISTURBANCE/DEEP MSTR WL EXIT LATE TODAY/
TNGT...SO THE SN WL DIMINISH. BUT LINGERING ALBEIT WEAKENING CYC NNE
FLOW OFF LK SUP WL MAINTAIN OVC LO CLDS/LIFR CIGS.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 503 AM EST TUE DEC 23 2014

LOW PRESSURE SLOWLY LIFTING OVER THE WESTERN GREAT LAKES TODAY WILL
RESULT IN EAST WINDS ON LK SUPERIOR...PERHAPS GUSTING TO GALE FORCE
OVER WESTERN LK SUPERIOR. WINDS WILL DIMINISH TONIGHT INTO WEDNESDAY
AS THE LOW SLIDES DIRECTLY OVER LAKE SUPERIOR. AS THE LOW WEAKENS...
ANOTHER MUCH STRONGER DEEPENING LOW WILL LIFT NORTHWARD OVER THE
CENTRAL GREAT LAKES BY WEDNESDAY NIGHT. EXPECT NORTHERLY WINDS TO
INCREASE TO 30 KTS OVER EASTERN LK SUPERIOR CLOSER TO THE STRONG LOW
PRESSURE SYSTEM. THE PRESSURE GRADIENT WILL BE TIGHEST ON THE WEST
FLANK OF THIS LOW LATE WEDNESDAY NIGHT INTO EARLY THURSDAY MORNING.
GALE GUSTS COULD OCCUR OVER EASTERN LK SUPERIOR AT THAT TIME. WINDS
BACK NW ON THURSDAY AND DIMINISH TO LESS THAN 20 KTS BY AFTN AS THE
LOW PRESSURE SYSTEM MOVES FARTHER AWAY FM THE AREA. ANOTHER LOW
PRESSURE SYSTEM WILL SLIDE OUT OF THE PLAINS OVER THE UPPER GREAT
LAKES FRIDAY INTO SATURDAY. NORTHERLY WINDS WILL BACK NORTHWEST AND
MAY REACH 30 KTS ON SATURDAY...MAINLY OVER EAST HALF OF LK SUPERIOR.
WINDS DIMINISH AGAIN BY SUNDAY AS HIGH PRESSURE BEGINS TO BUILD
TOWARD THE REGION FM THE PLAINS.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
  WINTER WEATHER ADVISORY UNTIL 7 PM EST /6 PM CST/ THIS EVENING
     FOR MIZ001>005-009-010-084.

LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...07
LONG TERM...JLA
AVIATION...07
MARINE...JLA





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