Area Forecast Discussion
Issued by NWS Marquette, MI

Home | Current Version | Previous Version | Graphics & Text | 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 251742
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
142 PM EDT WED MAR 25 2015

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 528 AM EDT WED MAR 25 2015

THE NEGATIVELY TILTED SHORTWAVE SET UP FROM E ND THROUGH S WI AND IN
WILL CONTINUE TO NEAR THE AREA...ALONG WITH 2 DISTINCT AREAS OF LOW
PRESSURE THAT ARE MAKING THE SPECIFICS OF THE FCST DIFFICULT. THE S
SFC LOW IS OVER S LAKE MI EARLY THIS MORNING...AND THE 2ND IS ACROSS
NW MN. OUR WEATHER INITIALLY IS STEMMING FROM THE S LOW. WHILE RADAR
REFLECTIVITY VALUES SHOW A GOOD AMOUNT OF LIGHT REFLECTIVITY
VALUES...THE INITIAL STUFF IS A BIT MISSLEADING. WITH IT TAKING A
BIT TO MOISTEN THE LOWER LEVELS AND GET PRECIP TO HIT THE GROUND.
THE SFC OBSERVATIONS HAVE BEEN VERY HELPFUL THIS MORNING
/CEILING...VIS...WX IF AVAILABLE/.

MIXED PRECIP IS WEAKENING AS IT EXITS N WI AND PUSHES INTO UPPER MI.
LATEST RADAR IMAGERY SHORTLY AFTER 08Z SHOWS A CONVECTIVE LOOK TO
THE RAIN/SNOW SHOWERS STRETCHING FROM SHAWNO THROUGH THE S PORTION
OF THE DOOR PENINSULA. WILL CONTINUE TO TRACK THIS AND UPDATE THE
ONGOING FCST AS NEEDED. KEPT THE SPS GOING EARLY THIS MORNING TO
HIGHLIGHT THE POTENTIAL FOR WET SLUSHY SNOW DURING THE MORNING
COMMUTE...AS WELL AS AROUND 2-3IN OF SNOW. THIS STILL LOOKS
REASONABLE. AS WE MOVE FARTHER INTO THE MORNING HOURS THE POTENTIAL
FOR FREEZING RAIN BECOMES LESS AND LESS LIKELY...AS COLDER AIR
BEGINS TO CREEP IN. ROAD TEMPS ARE IN THE 20S OVER THE CENTRAL US-41
CORRIDOR FROM S OF HARVEY TO N OF RAPID RIVER...AND E THROUGH ERY.
OTHERWISE...30S ARE COMMON. IF ANY FREEZING RAIN DOES HAPPEN...NEAR
LAKE MI THIS MORNING THE IMPACT WILL LIKELY BE MINIMIZED DUE TO THE
WARMER ROAD SURFACES.

OVER THE W...THE STEADY SNOW DROPPING VIS DOWN TO AROUND 2SM AT IWD
AT 09Z IS FIGURED TO TRACK E OF THE AREA SHORTLY AFTER 12Z. ALTHOUGH
THIS WILL BE THE END OF THE THE HEAVIER/WET SNOW...ADDITIONAL LAKE
ENHANCED SNOW SHOWERS WILL INVADE DURING THE LATE MORNING/AFTERNOON
HOURS FROM THE NW. THIS WILL BE THANKS TO THE SECOND LOW PUSHING
ACROSS THE ARROWHEAD OF MN AROUND 18Z SHIFTING AND WRAPPING IN AN
ADDITIONAL TROUGH AND COLDER AIR. 850MB TEMPS SHOULD FALL TO AROUND -
6C OVER THE W HALF BY 18Z.

ALTHOUGH COLDER AIR WILL BE PRESENT ALOFT THIS AFTERNOON...SFC
TEMPS SHOULD STILL BE ABLE TO RISE INTO THE MID 30S TO LOW 40S
/WARMEST S CENTRAL/. AS A RESULT...SOME OF THE PRECIP WILL LIKELY
CHANGE OVER TO RAIN BEFORE TURNING BACK INTO SNOW SHOWERS AGAIN
LATER THIS AFTERNOON. THE RAIN POTENTIAL LOOKS MINIMAL...ESPECIALLY
IMPACT WISE. OPTED TO ADD MORE OF A LATE MORNING/EARLY AFTERNOON DRY
SLOT /WHEN THE BEST CHANCE OF RAIN WOULD BE/ ACROSS OF CENTRAL UPPER
MI...AS HAS BEEN SHOWN IN THE SMALLER SCALE FCST SOLUTIONS.

INCREASED LAKE ENHANCED POPS FOR LATER THIS AFTERNOON INTO TONIGHT
OVER THE W TO WNW WIND SNOW BELTS OF W UPPER MI...EVEN THOUGH 850MB
TEMPS OF -6 TO -8C WILL NOT FALL TO A MORE FAVORABLE -12C UNTIL
CLOSER TO DAYBREAK THURSDAY. SNOW TO LIQUID RATIOS NEAR 10:1 AT 00Z
THURSDAY WILL SLOWLY FALL TO A MORE IMPRESSIVE 18:1 THROUGH THE
NIGHT. THE POTENTIAL EXISTS FOR 4-5IN OF SNOW TONIGHT...WITH THE
HIGHEST FALLING ACROSS THE HIGHER TERRAIN /PORCUPINE MOUNTAINS AND
NEAR TWIN LAKES/.

.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 546 AM EDT WED MAR 25 2015

WHILE THERE WILL BE OCCASIONAL DAYS OF ABOVE NORMAL TEMPS THRU THE
FIRST WEEK OF APR...IT APPEARS THE PATTERN ON THE WHOLE WILL SUPPORT
NORMAL TO BELOW NORMAL TEMPS WITH BLO NORMAL PROBABLY THE MORE
COMMON OUTCOME FOR THE MAJORITY OF DAYS OVER THE NEXT 2 WEEKS. PER
GFS AND GEM ENSEMBLES...THERE SHOULD BE SOME RETROGRESSION OF THE
NRN STREAM MEAN POSITIVE HEIGHT ANOMALY OVER WRN NAMERICA AND THE
MEAN NEGATIVE HEIGHT ANOMALY OVER ERN NAMERICA E OF HUDSON BAY. THIS
WILL RESULT IN MAINTENANCE OF A POOL OF COLD AIR ACROSS ERN CANADA
WHICH WILL SLOWLY SHIFT E TO ENCOMPASS MORE OF CANADA WITH TIME. FOR
UPPER MI...THE COLD AIR WILL BE TAPPED EASILY...AND THUS BLO NORMAL
TEMPS SHOULD BE THE MORE COMMON DAILY RESULT OVER THE NEXT 2 WEEKS.
IN CONTRAST TO THE VERY DRY SYNOPTIC PATTERN THAT HAS DOMINATED THE
UPPER LAKES AND UPPER MISSISSIPPI VALLEY SO FAR THIS YEAR...IT
APPEARS WE MAY BE HEADING FOR A PERIOD OF WETTER WEATHER OVER THE
NEXT 1 TO 2 WEEKS AS SRN STREAM ENERGY MOVES ACROSS THE CONUS AND
TAKES ADVANTAGE OF THE TEMP CONTRAST ACROSS THE MIDDLE OF THE
CONTINENT. PATTERN COULD SUPPORT MDT/HVY PCPN PRODUCING SYSTEMS E OF
THE ROCKIES...AND WITH THE POOL OF COLD AIR ACROSS CANADA...
POTENTIAL WILL ALSO BE THERE FOR SIGNIFICANT LATE SEASON SNOWFALLS
IN UPPER MI. OPERATIONAL GFS RUNS AND GEM ENSEMBLES OVER ROUGHLY THE
LAST WEEK HAVE CERTAINLY SHIFTED TO SUGGESTING A WETTER PATTERN THAN
WE`VE SEEN SO FAR THIS YEAR.

BEGINNING THU...IN THE WAKE OF SURFACE-850MB TROF DROPPING ACROSS
THE AREA TONIGHT...MUCH COLDER AIR WILL MOVE INTO THE UPPER LAKES ON
THU. 850MB TEMPS ACROSS LAKE SUPERIOR RANGING FROM -13C W TO -8C E
AT 12Z THU WILL FALL TO -15C TO -18C IN THE AFTN. THIS COLD AIR
COMBINED WITH DEEP MOISTURE AND WEAK FORCING UNDER MID LEVEL TROF
WILL LEAD TO LAKE ENHANCEMENT OFF LAKE SUPERIOR IN THE MORNING...AND
THEN A TRANSITION TOWARD PURE LES DURING THE AFTN AS DEEPER MOISTURE
DEPARTS. UNDER A GENERAL NORTHERLY LOW LEVEL WIND FLOW...HIGHEST
POPS/GREATEST SNOW ACCUMULATIONS WILL BE FOCUSED IN THE N WIND
FAVORED HIGHER TERRAIN AREAS DOWNWIND OF THE OPEN WATER ON LAKE
SUPERIOR (GOGEBIC/ONTONAGON COUNTIES AND FROM THE HURON MTNS OVER TO
WRN ALGER COUNTY. FARTHER E...HIGH ICE CONCENTRATION OVER ERN LAKE
SUPERIOR SHOULD HAVE A SIGNIFICANT NEGATIVE IMPACT ON LES E OF
MUNISING. DEEPENING AND DESCENDING DGZ WILL HELP TO FLUFF UP
SNOW/INCREASE SNOW TO WATER RATIOS. AT THIS POINT...SNOWFALL AMOUNTS
IN THE FAVORED AREAS ON THU SHOULD RANGE FROM 2-4 INCHES...LOCALLY
UP TO 5. IN ADDITION TO THE SNOW...THE NORTHERLY WINDS WILL BE GUSTY
TO 20-30KT...ESPECIALLY OVER THE KEWEENAW AND NCNTRL. WITH THE
FLUFFIER NATURE OF THE SNOW...THERE WILL BE SOME BLOWING SNOW.

850MB TEMPS FALL A LITTLE MORE THU NIGHT...BOTTOMING OUT AROUND
-20C. PASSING WEAK SHORTWAVE SHOULD GIVE LES A LITTLE BOOST THU
NIGHT THOUGH MODELS DON`T SHOW MUCH IMPACT ON MOISTURE OR INVERSION
HEIGHT WHICH IS INDICATED AT AROUND 5KFT. EXPECT ANOTHER INCH OR 2
OF SNOW IN THE N WIND FAVORED AREAS. SINCE DGZ OCCUPIES A GOOD
PORTION OF THE CONVECTIVE LAYER...WOULDN`T BE TOO SURPRISED TO SEE
LOCALIZED HIGHER AMOUNTS.

AS MIDLEVEL TROF SHIFTS E ON FRI...CENTER OF ARCTIC HIGH PRES WILL
DRIFT SE TO THE WESTERN GREAT LAKES REGION. INCREASED
DRYING/MODERATION OF AIR MASS AND THE DISRUPTIVE EFFECT OF LATE MAR
SOLAR HEATING WILL BRING AN END TO LIGHT LES DURING THE DAY FROM W
TO E. WITH THE HIGH DRIFTING ACROSS THE AREA FRI NIGHT...STAGE WILL
BE SET FOR A VERY COLD LATE MAR NIGHT UNDER CALM WIND AND DRY AIR
MASS (PRECIPITABLE WATER UNDER ONE-TENTH OF AN INCH). RECENT
ADDITION OF NEW SNOW ON THE GROUND IN MANY AREAS WILL FURTHER AID
THE COOLING. STRONGLY FAVORED THE COLDEST AVBL GUIDANCE...THE BIAS
CORRECTED CANADIAN GLOBAL MODEL WHICH OFTEN PERFORMS VERY WELL ON
EXCELLENT RADIATIONAL COOLING NIGHTS. MANY INTERIOR LOCATIONS SHOULD
FALL SUBZERO WITH TEENS BLO ZERO CERTAINLY POSSIBLE IN THE
TRADITIONAL COLDEST SPOTS. THE LOWEST TEMP OFF THE CANADIAN BIAS
CORRECTED IS -15F AT PEAVY FALLS.

SAT WILL BE SUNNY AND WARMER (MOVING CLOSER TO NORMAL FOR TEMPS...
ESPECIALLY W). SOUTHERLY WINDS WILL BEGIN TO INCREASE SAT...BUT MORE
SO SAT NIGHT DUE TO TIGHTENING PRES GRADIENT BTWN DEPARTING HIGH AND
SFC LOW PRES MOVING TO SRN MANITOBA. THAT LOW WILL BE ASSOCIATED
WITH A STRONG SHORTWAVE THAT WILL REACH THE UPPER LAKES ON SUN.
VIGOROUS DYNAMICS ASSOCIATED WITH 12HR 500MB HEIGHT FALLS OF 160-
200M...AND A PERIOD OF STRONG ISENTROPIC ASCENT WILL SUPPORT AT
LEAST A PERIOD OF PCPN LATE SAT NIGHT/SUN. GFS IS A GOOD 6HRS FASTER
THAN THE ECMWF/CANADIAN AND WOULD SPREAD PCPN ACROSS THE ENTIRE FCST
AREA OVERNIGHT SAT NIGHT WHEREAS THE ECMWF/CANADIAN HOLD PCPN OFF
UNTIL AFTER 12Z SUN. MIXING RATIOS OF 4G/KG ARE AVBL ON THE 295K SFC
(725-750MB)...SO THERE COULD BE A QUICK BURST OF DECENT SNOWFALL
DURING THE SHORT-LIVED PEAK ISENTROPIC ASCENT (1-2 INCHES OF SNOW).
WHILE THERE IS SOME CONCERN FOR ENOUGH WARMING TO CAUSE MIXED
PTYPES...BELIEVE STRENGTH OF UPWARD MOTION AND TIME OF DAY (ARRIVING
LATE NIGHT OR MORNING) WILL MAKE THIS INITIAL PERIOD OF PCPN ALL
SNOW. SYSTEM IS STILL FAR ENOUGH OUT TO ALLOW FOR IMPORTANT
ADJUSTMENTS IN FUTURE MODEL RUNS. IF SHORTWAVE TRACKS A BIT FARTHER
S AND UPPER MI ENDS UP ON THE CYCLONIC SIDE OF THE VORT TRACK...A
MORE SIGNIFICANT PCPN EVENT WILL OCCUR. WILL KEEP PCPN IN THE FCST
THRU SUN AND EVEN SUN NIGHT AS THERE ARE HINTS OF A SECONDARY WAVE
SWEEPING THROUGH THE AREA. AFTER THE INTIAL BURST OF SNOW WITH THE
STRONG ISENTROPIC ASCENT...ANY LIGHTER SNOW SUN SHOULD MIX WITH OR
EVEN CHANGE TO RAIN FOR A TIME UNDER DAYTIME HEATING...THEN CHANGE
BACK TO SNOW UNDER CAA SUN NIGHT. VIGOROUS SYSTEM SHOULD RESULT IN
WINDY CONDITIONS FOR MUCH OF THE AREA SUN.

DRY WEATHER WILL FOLLOW FOR MON...THEN WAA PATTERN AHEAD OF THE NEXT
SHORTWAVE APPROACHING THE NRN PLAINS MAY RESULT IN RAIN AND/OR SNOW
DEVELOPING TUE. WITH LOW CONFIDENCE ONLY SCHC POPS WERE UTILIZED
ACROSS THE N AND E.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 141 PM EDT WED MAR 25 2015

A LOW PRESSURE SYSTEM MOVING NORTH OF THE AREA WILL BRING SNOW TO
THE TAF SITES...ESPECIALLY KIWD AND KCMX...THIS AFTERNOON INTO THIS
EVENING. LAKE EFFECT WILL THEN INCREASE LATE THIS EVENING THROUGH
THURSDAY AS COLDER AIR MOVES IN ON N-NW WINDS. EXPECT SOME
IMPROVEMENT BETWEEN THE SNOW ASSOCIATED WITH THE LOW AND THE LAKE
EFFECT...BUT CONDITIONS WILL DEGRADE ONCE AGAIN THIS EVENING INTO
THURSDAY.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 457 AM EDT WED MAR 25 2015

TWO AREAS OF LOW PRESSURE ACROSS N MN AND S LAKE MI WILL MERGE OVER
LAKE SUPERIOR THIS AFTERNOON...AND SHIFT E ACROSS ONTARIO BY THE END
OF THE DAY AT WHILE DEEPENING. A LINGERING TROUGH ACROSS LAKE
SUPERIOR WILL EXIT TO THE SE THURSDAY MORNING. A FEW N GALE FORCE
GUSTS TO 35KTS WILL BE POSSIBLE OVER MAINLY N AND CENTRAL LAKE
SUPERIOR THURSDAY MORNING...BEFORE SLOWLY DIMINISHING THROUGH THE
DAY.

EXPECT A LOW OVER MANITOBA ON THURSDAY TO BRIEFLY SETTLE ACROSS THE
UPPER GREAT LAKES FRIDAY INTO EARLY SATURDAY...AND CONTINUE TO THE
OHIO VALLEY SATURDAY NIGHT. LOW PRESSURE STRETCHING FROM HUDSON BAY
TO S MANITOBA SATURDAY NIGHT WILL THEN SWING ACROSS CENTRAL ONTARIO
AND LAKE SUPERIOR SUNDAY AFTERNOON...AND INTO QUEBEC SUNDAY NIGHT.
ANOTHER PERIOD OF GUSTS OF 35 KTS TO NEAR 40KT GUSTS OF THE SW TO W
WILL BE POSSIBLE LATE SATURDAY NIGHT THROUGH SUNDAY...AND LINGER
OVER THE E HALF OF LAKE SUPERIOR OUT OF THE NW AT 35KTS SUNDAY NIGHT.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...KF
LONG TERM...ROLFSON
AVIATION...TITUS
MARINE...KF



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