Area Forecast Discussion
Issued by NWS Marquette, MI

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000
FXUS63 KMQT 271738
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
1238 PM EST TUE JAN 27 2015

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 409 AM EST TUE JAN 27 2015

00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW NW FLOW ALOFT OVER
THE GREAT LKS BTWN HI AMPLITUDE RDG OVER THE ROCKIES AND DEEP TROF
OVER THE E SUPPORTING INTENSE WINTER STORM THAT IS IMPACTING NEW
ENGLAND. SHRTWV DIGGING SEWD WITHIN THIS NW FLOW/DEEPER CLDS THAT
CAUSED PERIOD OF SN LAST EVNG ARE NOW SE OF THE AREA...SO LINGERING
LIGHT SN OVER THE CENTRAL CWA IS DIMINISHING WITH THE APRCH OF
SHRTWV RDG AXIS/DNVA/DEEP LYR QVECTOR CNVGC AND DRIER MID LVL AIR
SHOWN ON THE 00Z INL/YPL RAOBS. THESE RAOBS SHOW SOME LLVL MSTR BLO
INVRN...SO PLENTY OF LO CLDS LINGER UPSTREAM OVER NRN MN/NW ONTARIO.
HOWEVER...WITH 00Z H85 TEMP ONLY -5C AT INL...THE INCOMING AIRMASS
IS NOT SUFFICIENTLY COLD TO SUPPORT LES. COLDER AND DRIER LLVL AIR
IS STILL PRESENT TOWARD THE E AND ARCTIC HI PRES IN QUEBEC...WITH
MOCLR SKIES REPORTED EARLY THIS MRNG AT NEWBERRY AND THE SAULT.

MAIN FCST CONCERNS FOR TODAY/TNGT WL BE CLD TRENDS/IMPACT ON TEMPS.

TODAY...UPR MI WL BE DOMINATED BY DNVA/DEEP LYR QVECTOR DVGC
ASSOCIATED WITH APRCHG SHRTWV RDG. SO AFTER ANY LINGERING LIGHT SN
ENDS EARLY THIS MRNG...THE DAY SHOULD BE DRY AS SFC RDG AXIS
EXTENDING WSW FM THE HI CENTER IN QUEBEC SHIFTS OVER THE CWA.
DESPITE THE MID LVL DRYING...LINGERING LLVL MSTR TRAPPED BLO
LOWERING/STRENGTHENING SUBSIDENCE INVRN WL LIKELY MAINTAIN GENERALLY
MOCLDY SKIES...IN LINE WITH UPSTREAM OBS. ONE EXCEPTION SHOULD BE
THE ERN CWA...WHERE LIGHT E WIND WL MAINTAIN THE LLVL DRY AIR AND
ALLOW FOR MOSUNNY SKIES. ANOTHER AREA THAT MAY SEE SOME CLRG IS NEAR
LK SUP OVER THE NW CWA WHERE THE LLVL SW FLOW ON THE NRN FLANK OF
THE SFC RDG AXIS WL DOWNSLOPE AND RESULT IN LOWERING THE INVRN BASE
FURTHER. GOING FCST HI TEMPS MAINLY IN THE 20S...COLDEST OVER THE
E AND WARMEST OVER THE W...LOOK TO BE IN GOOD SHAPE.

TNGT...A SHRTWV IS FCST TO TRACK THRU FAR NRN ONTARIO. ALTHOUGH
LINGERING SHRTWV RDG AXIS WL FORCE THIS DISTURBANCE TO PASS TOO FAR
TO THE N TO BRING PCPN TO ALL BUT FAR NRN LK SUP LATE...AN INCRSG
LLVL ACYC SW FLOW BTWN THE SFC RDG AXIS SLIDING OVER LOWER MI AND
FALLING MSLP IN ONTARIO ASSOCIATED WITH THE PASSING SHRTWV WL ADVECT
SOME DRIER AIR INTO THE CWA. THIS DRYING PLUS MORE LLVL SUBSIDENCE
ASSOCIATED WITH THE STRENGTHENING ACYC FLOW WL LIKELY BREAK UP THE
LO CLDS OVER MUCH OF THE CWA...ESPECIALLY OVER NW NEAR LK SUP WHERE
SW WINDS DOWNSLOPE. OVER THE E...THE SW FLOW OFF LK MI MIGHT DRAW
MORE LO CLDS INTO THAT AREA. DESPITE ANY CLRG OF THE LOWER CLDS...
STRONGER WINDS AND INCRSG MID/HI CLDS ON THE SRN FLANK OF THE
DISTURBANCE PASSING TO THE N WL LIMIT THE DIURNAL TEMP FALL. EXPECT
THE LOWEST MIN TEMPS OVER THE E...WHERE TEMPS WL FALL OFF QUICKLY IN
THE EVNG BEFORE THE WINDS HAVE A CHC TO PICK UP A BIT OR ANY
CLDS ROLL IN LATER.

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 502 AM EST TUE JAN 27 2015

MUCH OF THIS PERIOD WILL BE IMPACTED BY THE STEADY 500MB LOW OVER E
AND E CANADA. FROM TIME TO TIME IT WILL BE EXTENDING A TROUGH ACROSS
MUCH OF THE E HALF OF THE U.S.

WARMEST DAY THIS PERIOD WILL BE WEDNESDAY...WITH HIGHS GENERALLY 30-
35F ON LIGHT S FLOW. A LOW OVER N HUDSON BAY  AND AN ADDITIONAL LOW
ACROSS THE N/CENTRAL PLAINS WILL PUSH A TROUGH OVER LAKE SUPERIOR
WEDNESDAY NIGHT. THIS WILL BRING THE BEST CHANCE OF WIDESPREAD SNOW
THROUGH THE LONG TERM PERIOD. HAVE ADJUSTED THE HWO MESSAGE TO
INCLUDE MAINLY THE TIP OF THE KEWEENAW AND E OF A LINE FROM MQT TO
ESC FOR THE POTENTIAL FOR MODERATE SNOW AMOUNTS. EXACT AMOUNTS VARY
SIGNIFICANTLY DEPENDING ON WHAT MODEL IS USED. FOR EXAMPLE AT KSAW
FOR WEDNESDAY NIGHT BUFKIT IS INDICATING THE POTENTIAL FOR 1-2IN
/00Z AND 06Z MODEL RUNS/. THE GFS IS SHOWING CLOSER TO 4-6IN. TAKING
A LOOK AT THE PRECIP FIELDS...THE 27/00Z ECMWF ALIGNS BETTER WITH
THE NAM WHILE THE CANADIAN IS CLOSER TO THE GFS. WILL CONTINUE A
FCST OF 2-5IN FOR MUCH OF THE CWA FROM WED THROUGH THURSDAY...WITH
ONLY 1-2IN ALONG THE WI BORDER.  ONLY LIMITED SNOW IS EXPECTED OVER
THE UPSLOPE N CENTRAL AND E LOCATIONS BAST WEDNESDAY NIGHT/THURSDAY
MORNING.

THE TROUGH WILL WEAKEN THURSDAY/THURSDAY NIGHT AS THE LOW ACROSS THE
PLAINS SHIFTS TO S LOWER MI...AND THE NEW ENGLAND STATES.
HOWEVER...INCREASED N-NNW WINDS THURSDAY AFTERNOON LOOK
REASONABLE...WITH A 30-40KT LLJ SET UP...EXPECT ABOVE 925MB. THIS
WILL BE AS UPPER MI BECOMES STUCK BETWEEN THE EXITING LOW PUSHING
TOWARDS THE LOWER GREAT LAKES AND STRONG HIGH PRESSURE NEARING FROM
THE W. LOOK FOR PATCHY BLOWING SNOW TO DEVELOP THURSDAY ALONG LAKE
SUPERIOR...REDUCING VIS.

FRIDAY INTO EARLY SATURDAY... EXPECT THE HIGH MENTIONED ABOVE OVER
SASKATCHEWAN ON THURSDAY TO SINK ACROSS MN AND W LAKE SUPERIOR
FRIDAY MORNING...AND INTO THE OHIO VALLEY AND MID ATLANTIC STATES
SATURDAY. COLD AIR WILL BE OVERHEAD...WITH HIGHS IN THE LOW TO MID
TEENS FRIDAY. WHILE LOW LEVEL MOISTURE AROUND 800MB AND BELOW WILL
REMAIN TRAPPED UNDER THE LOWERING INVERSION THURSDAY-FRIDAY...AND
THE DGZ WILL BE WITHIN THIS MOISTURE LAYER...NO HEADLINE LES IS
ANTICIPATED. THIS WILL BE EVEN THROUGH SLR VALUES CLIMB BACK TO 20-
25:1. LESS THAN FAVORABLE W-SW WINDS FRIDAY EVENING SHOULD PUSH MUCH
IF NOT ALL OF THE LINGERING LIGHT SNOW SHOWERS BACK INTO LAKE
SUPERIOR. THE DRY WEATHER WILL ONLY BE TEMPORARY.

REST OF SATURDAY... A BRIEF TROUGH OF LOW PRESSURE WILL PUSH ACROSS
LAKE SUPERIOR ON SATURDAY...BEFORE STRONGER HIGH PRESSURE NEARS FROM
CENTRAL CANADA. TIMING THIS TROUGH IS IS STILL A BIT ROUGH...AS THE
GFS/ECMWF/CANADIAN DIFFER BY 6-12HRS. THE 27/00Z CANDIAN AND 26/12Z
ECMWF ARE PRETTY CONSISTANT...WHILE THE 27/00Z GFS IS ON THE SLOW
SIDE. EITHER WAY IT WILL USHER IN ANOTHER ROUND OF COLD AIR. HIGHS
SUNDAY SHOULD TOP OUT 10-17F.

SUNDAY THROUGH MONDAY... STRONGER AND COLD 30.9 INCH/1040-1050MB
HIGH PRESSURE OVER MUCH OF CENTRAL CANADA FRIDAY AND SATURDAY WILL
SLOWLY WEAKEN TO 30.6IN/1033-1037MB AS IT SETTLES ACROSS THE N
PLAINS/ UPPER MS VALLEY/UPPER GREAT LAKES TO START THE NEXT WORK
WEEK.   HIGHS MONDAY MAY ONLY BE IN THE SINGLE DIGITS ABOVE ZERO.
THE HIGH WILL CONTINUE TO SINK SE ACROSS THE MID MS VALLEY/OHIO
VALLEY MONDAY NIGHT...AND MID ATLANTIC STATES TUESDAY-WEDNESDAY. THE
GFS IS PERSISTENT IN KEEPING THE HIGH IN PLACE...WHILE THE 26/12Z
ECMWF IS MORE PROGRESSIVE. MORE ON THIS WHEN WE START FCSTING FOR
MID NEXT WEEK.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1238 PM EST TUE JAN 27 2015

LINGERING LOW CLOUDS WILL BE SLOW TO EXIT OVER MUCH OF THE W HALF OF
UPPER MI THIS AFTN/EVENING UNDER LIGHT WIND FIELDS. AT KIWD/KSAW...
MVFR CIGS ARE LIKELY TO LINGER INTO THE EVENING. SLIGHT
STRENGTHENING OF DOWNSLOPE WIND SHOULD ALLOW MVFR CIGS TO SCATTER
OUT AT KIWD LATE THIS EVENING. IT MAY NOT BE UNTIL OVERNIGHT THAT
MVFR CIGS SCATTER OUT AT KSAW. RECENT VIS SATELLITE IMAGERY SHOWS
GRADUAL EXPANSION OF LOWER CLOUDS TOWARD KCMX. SO...IT APPEARS MVFR
CIGS WILL LIKELY DEVELOP AT KCMX IN THE NEXT COUPLE OF HRS...AND
THEN LINGER THRU THE EVENING. VFR CONDITIONS SHOULD BE THE RULE AT
ALL TERMINALS LATE TONIGHT THRU WED MORNING.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 409 AM EST TUE JAN 27 2015

EXPECT S TO SW WINDS UNDER 20 KTS TO DOMINATE THRU WED AS A HI PRES
RIDGE OVER UPPER MI TODAY SINKS SLOWLY INTO THE LOWER GREAT LAKES.
ON THE NORTHERN FLANK OF A HI PRES RIDGE ORIENTED ACROSS THE CENTRAL
GREAT LAKES. LO PRES WILL THEN TRACK FROM THE MID MISSISSIPPI VALLEY
WED NIGHT TO THE LOWER LAKES THU NIGHT. BEHIND THE LOW...N TO NW
WINDS WILL INCREASE TO 20-30KT AND THEN TO GALE FORCE LATE THU AND
THU NIGHT. SINCE THESE STRONG WINDS WILL DRAW MUCH COLDER ARCTIC AIR
INTO THE UPPER LAKES...HEAVY FREEZING SPRAY WILL DEVELOP OVER MUCH
OF THE LAKE AND CONTINUE INTO FRI...WHEN WINDS/WAVES WILL DIMINISH
WITH THE CLOSER APPROACH OF CANADIAN HI PRES. ANOTHER DISTURBANCE
AND COLD FRONT MAY SWING ACROSS THE UPPER LAKES ON SAT.
&&

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

$$

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



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