Area Forecast Discussion
Issued by NWS Marquette, 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

496
FXUS63 KMQT 030821
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
321 AM EST WED FEB 3 2016

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 359 PM EST TUE FEB 2 2016

12Z RAOBS/LATEST WV IMAGERY AND RAP ANALYSIS SHOW POTENT SHRTWV
LIFTING NEWD INTO THE UPR MS RIVER VALLEY...WITH BAND OF HEAVY PCPN
IN THE COLD CONVEYOR BELT EXTENDING FM NEBRASKA INTO WI SHIFTING N
INTO THE SRN CWA AS DYNAMIC FORCING/H85-7 FGEN/UPR DVGC IN LEFT EXIT
OF SUPPORTING H3 JET STREAK AND RIGHT ENTRANCE OF ANOTHER JET STREAK
OVER SE CANADA IS FINALLY OVERCOMING DRY AIR SHOWN BTWN H85-7 ON THE
LOCAL 12Z RAOBS. 00Z-12Z 12HR H5 HGT FALLS ASSOCIATED WITH THIS
DISTURBANCE WERE AS GREAT AS 200M AT DODGE CITY KS...AND THE
ACCOMPANYING STRONG DYNAMIC FORCING HAS CAUSED SOME LTNG ON THE SRN
EDGE OF THE COLDER CLOUD TOPS AS FAR N AS SCENTRAL WI. SOME
LOCATIONS IN WI HAVE SEEN SN FALL AT THE RATE OF 2 INCHES/HR THIS
AFTN. DRY SLOTTING ON THE ACYC SIDE OF THE UPR LO TRACK IS PUSHING
INTO SRN MN/WI. THIS UPR LO APPEARS TO BE TRACKING FARTHER W THAN
EXPECTED.

FOCUS FOR THE SHORT TERM IS ON ONGOING HEADLINES ASSOCIATED WITH
APRCHG VIGOROUS SHRTWV AND IMPACT OF DRY SLOTTING ON SN TOTALS/MIX
WITH FZDZ.

LATE THIS AFTN/TNGT...SHRTWV LIFTING NEWD TOWARD THE UPR LKS IS FCST
TO WEAKEN A BIT AS IT REACHES NW WI AT 12Z WED. AREA OF ENHANCED UPR
DVGC/H85-7 FGEN OVER CCB AND UNDER SHARP DPVA/DEEP LYR QVECTOR CNVGC
AHEAD OF APRCHG SHRTWV WL BRING A PERIOD OF SOME MDT/HEAVY SN TO
MAINLY THE E 2/3 OF THE CWA THIS EVNG. H7 SPECIFIC HUMIDITY FCST UP
TO 4 G/KG OVER THE SE CWA WL ALLOW ABOUT 6 INCHES OF WET SN TO FALL
OVER THE SE CWA BEFORE DRY SLOTTING ON THE ERN FLANK OF APRCHG H5-7
LO CAUSES THE SN TO DIMINISH AS EARLY AS LATE EVNG-MIDNGT AT
MENOMINEE. ALTHOUGH THE SPECIFIC HUMIDITY IS FCST TO BE LOWER OVER
THE W /ABOUT 2 G/KG/...FCST SN/WATER RATIOS FCST AS HI AS 20-25:1
THIS EVNG AND MORE PROLONGED DEEPER MSTR AWAY FM MID LVL DRY
SLOTTING WL ALLOW SIMILAR OVERNGT SN TOTALS...ESPECIALLY OVER THE
FAR W NEAR THE PORCUPINE MTNS...WHERE A MORE UPSLOPE CYC NNE FLOW WL
BE THE RULE OVERNGT AND ADD SOME LK ENHANCEMENT WITH H85 TEMPS NEAR -
10C. SINCE THE KEWEENAW WL BE IMPACTED BY THIS MORE PERSISTENT
DEEPER RH AND THE LATEST WPC SN FCST SHOWS A MAXIMUM OVER THE WRN
CWA WITH SHIFT OF THE TRACK OF THE UPR LO TO THE W...OPTED TO
UPGRADE ADVY FOR THAT AREA TO A WARNING. THE 12Z NAM IS QUITE
AGGRESSIVE WITH THE DRY SLOTTING...SHOWING SOME MID LVL DRYING
IMPACTING THE AREA FM IRON RIVER TO THE HURON MTNS OVERNGT. ALTHOUGH
THE SHRTWV IS FCST TO WEAKEN A BIT OVERNGT...CURRENT STLT TRENDS
SUPPORT MORE EXTENSIVE MID LVL DRY SLOTTING AND EXPANDING POTENTIAL
MIX WITH FZDZ FARTHER TO THE W TO INCLUDE MOST OF THE SE HALF.
ALTHOUGH THE DISTURBANCE WL BE WEAKENING A BIT...NE H925 WINDS FCST
AS HI AS 35-40KTS WL ALLOW FOR BLSN...ESPECIALLY IN OPEN AREAS NEAR
LK SUP.

WED...BULK OF THE LATEST 12Z MODEL GUIDANCE CONTINUES TO SHOW AREA
OF DEEPER MID LVL MSTR WRAPPING BACK THRU THE CWA UNDER TRACK OF
OPENING SHRTWV LIFTING TO THE NE AND ACCOMPANYING DEEP LYR QVECTOR
CNVGC. SO AFTER SOME REDUCED POPS IN THE MRNG/MIX WITH FREEZING
DZ...BUMPED UP POPS INTO THE HI LIKELY RANGE FOR MORE SN WITH DEEPER
MSTR EXPANDING BACK INTO THE DGZ. ALTHOUGH SOME LES WL PERSIST OVER
THE W IN THE AFTN WITH CYC NNW FLOW OF COLDER AIR DROPPING H85 TEMPS
TO NEAR -15C BY 00Z THU...ARRIVAL OF DEEP LYR QVECTOR DVGC IN THE
WAKE OF PASSING SHRTWV SHOULD RESULT IN DIMINISHING PCPN.

.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 414 PM EST TUE FEB 2 2016

WEDNESDAY NIGHT...THE SURFACE LOW WILL BE OVER SOUTHWEST QUEBEC
WEDNESDAY EVENING WHILE THE UPPER LEVEL 500MB TROUGH AXIS LINGER
ACROSS THE UPPER PENINSULA. THIS TROUGH AXIS LINGERING OVER THE AREA
WILL KEEP 850MB TEMPS AROUND -14C TO -15C. THE COMBINATION OF DELTA
T VALUES AROUND 17C TO 18C ALONG WITH CONTINUED LOW LEVEL MOISTURE
WILL KEEP AN ENHANCED LAKE EFFECT SNOW POTENTIAL ACROSS THE AREA
THROUGH THE EVENING HOURS. MAINLY FOR NORTHWEST TO NORTH-NORTHWEST
WIND FAVORED LOCATIONS. OVERNIGHT THE TROUGH AXIS WILL SLIDE TO THE
EAST OF THE AREA AND THE DEEPER MOISTURE WILL SLIDE TO THE EASTERN
HALF OF THE U.P. THIS WILL ALLOW LAKE EFFECT SNOW TO SLOWLY DIMINISH
IN INTENSITY OVER THE WEST WHILE THE EAST CONTINUES TO LIGHT TO
MODERATE LAKE EFFECT SNOW. INVERSION HEIGHTS WILL DROP FROM 6-7KFT
IN THE EVENING OVER THE WEST TO AROUND 3 TO 4KFT OVERNIGHT...AGAIN
POINTING TOWARD THE DIMINISHING TREND. OVER THE EAST
HALF...INVERSION HEIGHTS WILL STAY AROUND 6-7KFT THROUGH THE
OVERNIGHT HOURS. A LARGE PORTION OF THE MOIST LAYER WILL BE IN THE
DGZ...WHICH WILL HELP TO SUPPORT HIGHER SNOWFALL RATIOS AROUND 19:1
TO 22:1 ALONG WITH ACCUMULATIONS BETWEEN 1 AND 3 INCHES FOR THE
NORTH TO NORTH-NORTHWEST WIND FAVORED LOCATIONS.

THURSDAY AND THURSDAY NIGHT...THE LOW PRESSURE CENTER WILL CONTINUE
TO SLIDE TO THE EAST THURSDAY MORNING AS A WEAK AND VERY BRIEF
SURFACE RIDGE SLIDES INTO THE AREA. THIS MAY ALLOW FOR A SLIGHT
REDUCTION IN LAKE EFFECT SNOW BUT IT WILL BE VERY BRIEF AS ANOTHER
SURFACE TROUGH AND UPPER LEVEL 500MB SHORTWAVE SLIDES THROUGH THE
AREA DURING THE AFTERNOON AND EVENING HOURS. THE INCREASED MOISTURE
ASSOCIATED WITH THE TROUGH ALONG WITH 850MB TEMPERATURES REMAINING
AROUND -14C TO -15C WILL ALLOW LAKE EFFECT SNOW TO KICK UP AGAIN.
THIS TIME THE MAIN AREA OF FOCUS WOULD BE MAINLY ALONG THE KEWEENAW
PENINSULA AS WINDS WILL BECOME WESTERLY TO WEST-SOUTHWESTERLY.
INVERSION HEIGHTS ARE PROGGED TO JUMP UP TO AROUND 6-8KFT AS THE
WAVE SLIDES THROUGH WITH FAIRLY DEEP MOISTURE. LIGHT TO MODERATE
SNOW TOTALS ARE EXPECTED AS THE WAVE IS SLIDING THROUGH THE AREA
QUICKLY. CURRENT THINKING IS THAT THE KEWEENAW AND EASTERN AREAS
NEAR LAKE SUPERIOR COULD SEE 1 TO 3 INCHES THURSDAY AFTERNOON
THROUGH THURSDAY NIGHT WITH LOCALLY HIGHER TOTALS POSSIBLE OVER THE
HIGH TERRAIN OF THE KEWEENAW.

FRIDAY THROUGH SATURDAY...DURING THE DAY FRIDAY WEST WINDS WILL
PREVAIL ACROSS THE UPPER GREAT LAKES REGION. THIS WILL HELP PEG ANY
LAKE EFFECT SNOW TO WESTERN U.P./KEWEENAW PENINSULA AND POSSIBLY
OVER EASTERN AREAS...MAINLY CLOSE TO THE SHORELINE. MOISTURE IS
PROGGED TO BE FAIRLY SHALLOW THROUGH THE DAY SO LAKE EFFECT SNOW
SHOULD BE FAIRLY LIGHT AS INVERSION HEIGHTS AND MOST OF THE MOISTURE
WILL REMAIN BELOW 5KFT. FRIDAY NIGHT THROUGH SATURDAY A WEAK SURFACE
TROUGH AND ASSOCIATED UPPER LEVEL 500MB TROUGH WILL SLIDE ACROSS THE
UPPER GREAT LAKES REGION. THIS WILL ONCE AGAIN ALLOW FOR INCREASED
MOISTURE WITH 850MB TEMPS REMAINING AROUND -14C TO -15C. THIS WILL
ALLOW LAKE EFFECT SNOW ALONG WITH LIGHT SYSTEM SNOW TO OCCUR ACROSS
THE AREA. RIGHT NOW THE FAVORED LAKE ENHANCEMENT LOOKS LIKE IT WOULD
OCCUR FOR NORTH TO NORTHWEST WIND FAVORED LOCATIONS...BUT THERE ARE
STILL SOME DIFFERENCES IN THE WIND FIELDS. DOES NOT LOOK TO BE A
MAJOR LAKE EFFECT EVENT AT THIS TIME.

SUNDAY THROUGH THE EXTENDED...BOTH THE EC AND GFS ARE SHOWING A
CLIPPER SYSTEM SLIDING THROUGH THE UPPER GREAT LAKE THROUGH THIS
TIME PERIOD. THIS WOULD END UP BRINGING WIDESPREAD SYSTEM SNOW
ACROSS THE U.P. SUNDAY AND SUNDAY NIGHT...TRANSITIONING TO LAKE
EFFECT/ENHANCED SNOW MONDAY THROUGH TUESDAY. WHILE THE LATEST GFS/EC
MODELS ARE IN BETTER AGREEMENT...PREVIOUS MODEL RUN COMPARISONS SHOW
THAT THERE HAS BEEN SOME DISAGREEMENTS FROM RUN TO RUN. AT THIS
POINT WILL NOT GET INTO THE SPECIFICS THIS FAR OUT. THE TREND WOULD
BE FOR THE CLIPPER SYSTEM TO SLIDE THROUGH DURING THAT TIME FRAME.
&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1253 AM EST WED FEB 3 2016

EXPECT IFR/LIFR CONDITIONS WITH SNOW ACROSS THE REGION THROUGH WED
AFTERNOON AS LOW PRESSURE MOVES THROUGH THE WRN GREAT LAKES. IN
ADDITION...WINDS WILL ALSO BECOME GUSTY OUT OF THE NE...CREATING
BLSN AT TIMES. NOT OUT OF THE QUESTION THERE COULD BE SOME FZDZ AT
SAW FOR A TIME LATE TONIGHT INTO WED WITH SOMEWHAT HIGHER
VSBYS...BUT CIGS SHOULD REMAIN IN THE IFR/LIFR RANGE EVEN IF THIS
OCCURS. EXPECT SOME IMPROVEMENT WED EVENING TO MVFR AS DRIER AIR
MOVES IN AND SFC RIDGE APPROACHES FROM THE WEST.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 414 PM EST TUE FEB 2 2016

WINDS OVER LAKE SUPERIOR WILL RAPIDLY INCREASE THIS AFTERNOON INTO
THIS EVENING AS LOW PRES TRACKS NORTHEAST FROM THE SOUTHERN
PLAINS...EVENTUALLY CROSSING FAR NORTHERN LOWER MI LATE TONIGHT INTO
WEDNESDAY MORNING. FREQUENT GALE FORCE GUSTS SHOULD OCCUR OVER NORTH
CENTRAL AND ADJACENT WESTERN LAKE SUPERIOR...SO GALE WARNING REMAINS
OVER THAT AREA FOR LATE EVENING THROUGH MID MORNING WEDNESDAY. AFTER
A PERIOD OF LIGHT WINDS THURSDAY...THE NEXT PERIOD OF STRONGER WINDS
WILL ARRIVE FRIDAY INTO SATURDAY WITH WINDS OF 20-30KT...STRONGEST
OVER EASTERN LAKE SUPERIOR. WINDS WILL INCREASE AGAIN SUNDAY INTO
MONDAY AS A LOW PRESSURE SYSTEM SLIDES INTO THE UPPER GREAT LAKES.
WIND WILL GENERALLY BE IN THE 20 TO 30 KNOT RANGE DURING THIS TIME
PERIOD.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
  WINTER STORM WARNING UNTIL 4 PM EST /3 PM CST/ THIS AFTERNOON
     FOR MIZ001>007-009-084-085.

  WINTER STORM WARNING UNTIL 1 PM EST THIS AFTERNOON FOR MIZ013-
     014.

  WINTER STORM WARNING UNTIL 6 AM CST WEDNESDAY FOR MIZ010>012.

LAKE SUPERIOR...
  GALE WARNING UNTIL 9 AM EST THIS MORNING FOR LSZ263-264.

LAKE MICHIGAN...
  GALE WARNING UNTIL 1 AM EST EARLY THIS MORNING FOR LMZ248-250.

&&

$$

SHORT TERM...KC
LONG TERM...KEC
AVIATION...JLB
MARINE...KEC



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