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 240537
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
1237 AM EST TUE FEB 24 2015

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 233 PM EST MON FEB 23 2015

UPPER AIR PATTERN CONSISTS OF A CLOSED 500 MB LOW OVER THE GREAT
BASIN WITH AN ASSOCIATED TROUGH...A CLOSED LOW OVER QUEBEC WITH A
DEEP TROUGH OVER THE ERN U.S. THIS MORNING. THERE IS ALSO SOME UPPER
LEVEL ENERGY ACROSS CENTRAL CANADA THAT IS MOVING SOUTH AND IS
POISED TO CARVE OUT A DEEP UPPER TROUGH OVER THE AREA AGAIN WITH
COLDER AIR RETURNING.

NAM BRINGS IN SOME DEEPER MOISTURE AND 850-500 MB Q-VECTOR
CONVERGENCE TONIGHT BEFORE BOTH DEPART THE AREA TUE MORNING. DID NOT
MAKE TOO MANY CHANGES TO THE GOING FORECAST OVERALL FOR TEMPERATURES
OR WEATHER WITH THE ONLY CHANGE OF BACKING THE TIMING OF POPS UP
TONIGHT A BIT. TEMPERATURES WILL BE TRICKY AND LOWERED THEM ABOUT 2
DEGREES FOR TONIGHT BASED ON THE DRYNESS OF THE COLD AIR...BUT KEPT
THE TEMPERATURE CURVE THE SAME WITH A NON-DIURNAL WARMING TREND
TONIGHT AND THEN NON-DIURNAL TREND FOR TEMPERATURES ON TUE AS COLD
AIR ARRIVES IN THE AFTERNOON WHICH SHOULD HAVE TEMPERATURES FALLING.
NOT REAL CONFIDENT ABOUT LAKE EFFECT SNOW BEHIND THIS SYSTEM TONIGHT
AS THERE IS A LOT OF ICE COVER ON LAKE SUPERIOR NOW...CLOSE TO 95
PERCENT AND HARD TO SAY WHERE HEAT WILL BREAK THROUGH THE ICE TO
CAUSE LAKE EFFECT SNOW BANDS AND HOW MUCH HEAT FROM THE ICE IS
AVAILABLE. WE DO GET CLOSE TO ADVISORY SNOW IN A FEW PLACES IN THE
KEWEENAW AND ALSO IN THE EAST BETWEEN 06Z AND 18Z ON TUE...BUT
TAKING THE MID AMOUNTS GETS JUST UNDERNEATH CRITERIA AND WILL NOT
ISSUE ADVISORIES FOR THIS. OVERALL...GOING FORECAST WAS GOOD AND
MADE VERY FEW CHANGES TO IT.

.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 335 PM EST MON FEB 23 2015

OVERALL...A GENERALLY QUIET AND COLD PERIOD OF WEATHER FOR THE END
OF FEBRUARY OVER THE UPPER GREAT LAKES REGION. AT THE START OF THE
FORECAST PERIOD...AN AREA OF LOW PRESSURE WILL BE NEAR JAMES BAY
AND MOVING EAST...WHILE A COLD FRONT WILL BE SHIFTING EAST AND AWAY
FROM UPPER MICHIGAN. THIS WILL USHER IN ANOTHER ARCTIC AIRMASS
TUESDAY NIGHT WHICH WILL REMAIN INTO WEDNESDAY (850MB TEMPS AROUND
-.27C). WHILE THE COLDEST AIR SHIFTS OFF TO THE EAST OF THE AREA
WEDNESDAY NIGHT...ANOTHER SHORTWAVE WILL SWEEP OVER THE AREA AND
BRING A REINFORCING SHOT OF COLD AIR (ALTHOUGH NOT AS COLD
AND...ONLY...AROUND -22C AT 850MB). WHILE THIS IS OCCURRING...THE
UPPER GREAT LAKES REGION WILL BE UNDER THE INFLUENCE OF A HIGH
PRESSURE RIDGE THROUGH AT LEAST SATURDAY...AS THE CENTER OF THE
HIGH TRACKS FROM ALBERTA TUESDAY NIGHT...TO THE DAKOTAS ON
THURSDAY...AND THE LOWER GREAT LAKES BY FRIDAY NIGHT. WITH THE COLD
AIR IN PLACE AND NORTHWESTERLY FLOW IN THE LOW LEVELS...LAKE EFFECT
POTENTIAL WILL DEPEND ON ANY GAPS IN OR THIN AREAS OF ICE. THIS HAS
MADE FOR TRICKY FORECASTS IN THE FIRST 24-36 HOURS OVER THE
LAST COUPLE OF DAY...WHICH IS COMPLICATED BY THE GUSTY SOUTHWESTERLY
WINDS THIS AFTERNOON AND TONIGHT AND THE STRONG NORTHWEST WINDS ON
TUESDAY. WOULD EXPECT SOME GAPS TO OCCUR IN SIMILAR LOCATIONS AS
SEEN THIS WEEKEND AND WILL FOLLOW THAT IDEA FOR POPS TUESDAY NIGHT
INTO THURSDAY. WILL KEEP POPS CAPPED AT CHANCE OVER THE WEST...AS
THERE HAS BEEN VERY LIMITED MOVEMENT OF THE THICKER ICE OVER THE
LAST COUPLE DAYS ON SATELLITE. OVER THE EAST...WILL SHOW LOCALIZED
AREAS OF LIKELY POPS INITIALLY BEFORE DIMINISHING. BASED OFF THIS
PAST WEEKEND...THE COVERAGE WILL BE LIMITED WITH THE THIN BANDS.
THEN HEADING TOWARDS FRIDAY AND SATURDAY...WINDS WILL BACK TO THE
WEST BUT FEEL THE WEAKENING NATURE AND COLD TEMPS WILL GROW THE ICE
ENOUGH TO BEGIN TO DIMINISH THE LAKE EFFECT AND SHIFT WHAT REMAINS
OFFSHORE. FINALLY FOR SUNDAY INTO MONDAY...AN UPPER TROUGH MOVING
SOUTH INTO THE SOUTHWEST CONUS FRIDAY INTO SATURDAY WILL EJECT OUT A
PIECE OF ENERGY TOWARDS THE LOWER GREAT LAKES SUNDAY INTO SUNDAY
NIGHT. CURRENT INDICATIONS FROM THE MODELS IS FOR MUCH OF THE ENERGY
TO STAY TO THE SOUTH OF THE AREA...BUT WILL CONTINUE TO SHOW CHANCE
POPS OVER THE SOUTH HALF OF THE CWA.

AS FOR TEMPERATURES...THE COLD AIR SURGING INTO THE AREA ON TUESDAY
NIGHT WILL BRING BORDERLINE WIND CHILL ADVISORY VALUES LATE TUESDAY
NIGHT INTO WEDNESDAY MORNING. THERE WILL BE SOME MODERATION ON
WEDNESDAY AND IT DOESN/T APPEAR LIKE IT WILL BE AS COLD AS SEEN
YESTERDAY...BUT HIGHS WILL STILL BE HOVERING AROUND 0 FOR MUCH OF
THE AREA. WITH CLEAR SKIES AND WEAKENING WINDS AWAY FROM ANY LAKE
EFFECT CLOUDS...WOULD EXPECT ANOTHER VERY COLD NIGHT ACROSS UPPER
MICHIGAN WEDNESDAY NIGHT. BASED OFF LAST NIGHT/S LOWS...OPTED TO
FOLLOW THE RECENT BETTER PERFORMING BIAS CORRECTED MODELS AND THEN
TREND DOWN IN THE NORMAL COLD SPOTS. THAT LOWERED TEMPS A GOOD 5-8
DEGREES IN SOME LOCATIONS AND WILL HAVE LOWS IN THE TEENS AND 20S
BELOW ZERO. AS TEMPERATURES BEGIN TO SLOWLY MODERATE ALOFT FOR THE
REST OF THE FORECAST PERIOD...HAVE SHOWN A GRADUAL WARMING
TREND...BUT STILL EXPECT TEMPERATURES TO BE BELOW NORMAL THROUGH THE
WEEKEND.

AS A FINAL NOTE...FEBRUARY 2015 IS A LOCK TO BREAK LAST
YEAR/S RECORD COLD FEBRUARY. THROUGH THE 22ND...THE AVERAGE TEMP
THIS MONTH HAS BEEN 2.9 DEGREES. PERFORMING A ROUGH CALCULATION
BASED OFF THE FORECAST DATA...WE SHOULD END UP RIGHT AROUND 2.5
DEGREES FOR THE AVERAGE TEMPERATURE THIS MONTH AT NWS MARQUETTE.
THAT WOULD BEAT THE RECORD OF 5.6 DEGREES SET JUST LAST YEAR. AT
OTHER SITES WITH LONGER PERIODS OF RECORD...THIS FEBRUARY WILL
LIKELY END UP AS A TOP 5 OR TOP 10 COLDEST FEBRUARY. MANY SITES HAVE
1936 AS THE COLDEST FEBRUARY ON RECORD...WHICH AT IRONWOOD EVEN
ENDED UP WITH AN AVERAGE TEMPERATURE BELOW ZERO (ALMOST 4
DEGREES COLDER THAN WHAT HAS OCCURRED THIS MONTH).
&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1237 AM EST TUE FEB 24 2015

AN AREA OF -SN IN ADVANCE OF AN APRCHG COLD FNT WL OVERSPREAD UPR MI
EARLY THIS MRNG...BRINGING A PERIOD OF MVFR AND PERHAPS IFR
CONDITIONS. THE BEST CHC FOR PERSISTENT IFR VSBYS DUE TO THE FALLING
-SN AND SOME BLSN WHIPPED UP BY GUSTY SW WINDS WL BE AT CMX...CLOSER
TO THE TRACK OF THE ASSOCIATED SHRTWV AND DEEPER MSTR. ALTHOUGH
THERE MAY BE SOME IMPROVEMENT IMMEDIATELY FOLLOWING THE FROPA AND
STRONGER DYNAMIC FORCING AFTER SUNRISE THIS MRNG...A REINFORCING
DISTURBANCE AND ATTENDANT ARCTIC COLD FROPA WL BRING MORE SHSN/GUSTY
NW WINDS/BLSN IN THE AFTN IN THE PRESENCE OF DIURNAL HEATING AND CAA
THAT SHARPEN LLVL LAPSE RATES. ALTHOUGH EXTENSIVE ICE COVER WL LIMIT
THE INTENSITY OF THE LES...THE BLSN AT THE MORE EXPOSED CMX LOCATION
WL LIKELY RESULT IN IFR VSBYS AT LEAST PART OF THE TIME UNTIL THE
EVNG...WHEN LARGER SCALE STRONG SUBSIDENCE IN THE WAKE OF THIS
DISTURBANCE SUPPRESSES THE LES OVER THE ENTIRE AREA.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 233 PM EST MON FEB 23 2015

SOUTHWEST GALES AROUND 35 KTS OVER PORTIONS OF LAKE SUPERIOR WILL
CONTINUE LATE THIS AFTERNOON THROUGH TONIGHT. A COLD FRONT WILL MOVE
ACROSS LAKE SUPERIOR LATE TONIGHT INTO TUESDAY MORNING AND SHIFT
WINDS TO THE NORTHWEST...THERE MAY BE A FEW GALE FORCE GUSTS TO 35
KNOTS BEHIND THE FRONT ON TUESDAY OVER EASTERN LAKE SUPERIOR. A HIGH
PRESSURE RIDGE WILL BUILD BACK INTO THE AREA WEDNESDAY AND REMAIN
INTO SATURDAY...LEADING TO GENERALLY LIGHT WINDS BELOW 20KTS. ICE
COVER IS EXTENSIVE...SO FREEZING SPRAY IS NOT A PROBLEM.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
  GALE WARNING UNTIL 7 AM EST /6 AM CST/ THIS MORNING FOR LSZ162-
     263-264-266.

LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...07
LONG TERM...SRF
AVIATION...KC
MARINE...07


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