Area Forecast Discussion
Issued by NWS Marquette, MI

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

000
FXUS63 KMQT 221941
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
241 PM EST THU JAN 22 2015

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 429 AM EST THU JAN 22 2015

A CLOUDY SKY COVERS ALL OF UPPER MICHIGAN EARLY THIS MORNING...AS
ABUNDANT LOW LEVEL MOISTURE REMAINS TRAPPED BELOW THE STRENGTHENING
SUBSIDENCE INVERSION (SEEN ON 00Z KINL SOUNDING) FROM THE HIGH
PRESSURE RIDGE OVER NORTHERN MINNESOTA. RAP ANALYSIS SHOWS A -12C
850MB THERMAL TROUGH SLIDING ACROSS CENTRAL/EASTERN LAKE SUPERIOR
EARLY THIS MORNING (ASSOCIATED WITH A SHORTWAVE MOVING THROUGH
NORTHERN ONTARIO AND BRUSHING NORTHERN LAKE SUPERIOR) AND AIDING
WEAK LAKE EFFECT SNOW SHOWERS IN THE NORTHWEST WIND SNOW BELTS OVER
EASTERN UPPER MICHIGAN. OVERALL THESE ARE FAIRLY WEAK AND DISJOINTED
DUE TO THE MARGINAL DELTA-T VALUES AND WEAK LOW LEVEL LAPSE RATES.
THOSE MARGINAL FEATURES HAVE ALSO LEAD TO OCCASIONAL PERIODS OF
FREEZING DRIZZLE LAST EVENING OVER THE KEWEENAW AND ALSO OVER THE
NORTH CENTRAL THROUGH THE NIGHT. WILL INCLUDE A PATCHY FREEZING
DRIZZLE MENTION FOR THE NEXT COUPLE OF HOURS...BUT EXPECT THERE TO
BE LITTLE TO NO IMPACT WITH THE PRECIP BEING PREDOMINATELY SNOW.
UNDER THE CLOUDY SKIES...TEMPERATURES HAVE BEEN SLOW TO FALL THROUGH
THE NIGHT...WITH 3AM TEMPERATURES STILL IN THE LOWER 20S.

THE HIGH PRESSURE RIDGE OVER MINNESOTA WILL QUICKLY SLIDE EAST
ACROSS UPPER MICHIGAN TODAY...AS THE PARENT HIGH MOVES FROM THE
CENTRAL PLAINS TO THE OHIO RIVER VALLEY. THIS WILL LEAD TO STEADILY
BACKING LOW LEVEL WINDS THIS MORNING AND SHIFT ANY REMAINING LAKE
EFFECT SNOW OVER THE EAST OFFSHORE. THE BIGGEST QUESTION WITH THE
FORECAST TODAY IS WHAT WILL HAPPEN TO THE CLOUDS. MOST MODELS ARE
INDICATING THAT THE LOW CLOUDS WILL SCATTER OUT LATE THIS MORNING
AND INTO THE AFTERNOON. DO HAVE SOME CONCERN WITH THAT DUE TO THE
UPSTREAM OBS STILL INDICATING LOW CLOUDS INTO EASTERN MINNESOTA AND
WESTERN WISCONSIN...ALONG WITH THE STRENGTHENING SUBSIDENCE
INVERSION ASSOCIATED WITH THE HIGH PRESSURE RIDGE MOVING THROUGH.
BUT WITH THE SOUTHWESTERLY FLOW INCREASING MIXING AND THE MOISTURE
LAYER BECOMING THIN...DID TREND THE FORECAST TOWARDS PARTLY CLOUDY.
THIS SITUATIONS ARE TRICKY...AS SOME AREAS WILL LIKELY CLEAR OUT
COMPLETELY (AIDED BY DOWNSLOPING SOUTHWESTERLY WINDS) WHILE THERE
COULD STILL BE POCKETS OF CLOUDY SKIES. AS THE LOW CLOUDS SCATTER
OUT...HIGH CLOUDS WILL BE THICKENING OVER THE AREA THIS
AFTERNOON/EVENING ASSOCIATED WITH THE APPROACHING CLIPPER SYSTEM.
THUS...WILL GRADUALLY INCREASE THE CLOUDS FROM THE NORTHWEST LATE
THIS AFTERNOON AND CONTINUE THROUGH THE NIGHT. LOWS WILL OCCUR THIS
EVENING AND THEN GRADUALLY WARM OVERNIGHT WITH THE INCREASING
SOUTHWESTERLY FLOW. THAT SOUTHWEST FLOW...WHICH WILL PRODUCE GALES
OVER WESTERN/CENTRAL LAKE SUPERIOR...IS EXPECTED TO LEAD TO GUSTY
CONDITIONS DEVELOPING OVER THE FAR WEST THIS AFTERNOON AND ACROSS
THE AREA TONIGHT. THINK THE STRONGEST GUSTS WILL REMAIN TOWARDS ISLE
ROYALE WHERE THE BEST PRESSURE FALLS ARE LOCATED...BUT STILL SHOULD
SEE SOME GUSTS TO 20-25KTS (AND 30KTS OVER THE KEWEENAW) TONIGHT.

AS THE COLD FRONT ASSOCIATED WITH THE CLIPPER SYSTEM APPROACHES LAKE
SUPERIOR TONIGHT...SHOULD SEE PRECIPITATION DROPPING SOUTHEAST
ACROSS WESTERN/CENTRAL LAKE SUPERIOR OVERNIGHT. SHOULD SEE IT
IMPACTING THE KEWEENAW PENINSULA BETWEEN 9-12Z. HAVE KEPT
PRECIPITATION AS SNOW FOR MOST LAND LOCATIONS THROUGH 12Z...BUT WITH
THE NAM INDICATING A WARM NOSE MOVING INTO WESTERN LAKE SUPERIOR
TOWARDS 12Z...DID ADD A MENTION OF FREEZING RAIN AND SLEET TO THAT
AREA.

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 241 PM EST THU JAN 22 2015

NAM SHOWS A DEEP 500 MB TROUGH OVER THE LOWER MISSISSIPPI RIVER
VALLEY 00Z SAT WITH A SHORTWAVE OVER THE UPPER GREAT LAKES. ANOTHER
SHORTWAVE DROPS INTO THE AREA LATE SAT NIGHT INTO SUNDAY WITH AN
ALBERTA CLIPPER TYPE SYSTEM. NAM SHOWS SOME DEEPER MOISTURE AND 850-
500 MB Q-VECTOR CONVERGENCE MOVING THROUGH ON SAT NIGHT INTO SUN
WITH BETTER MOISTURE AND DYNAMICS STAYING TO THE SOUTHWEST OF THE
AREA.

WILL NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST AND WILL KEEP
HIGHEST POPS ALONG THE WI BORDER AND IN THE SOUTH WITH THE ALBERTA
CLIPPER PASSING BY SAT NIGHT INTO SUNDAY. GOING TEMPERATURES LOOKED
GOOD AND DID NOT MAKE TOO MANY CHANGES TO THEM.

IN THE EXTENDED...GFS AND ECMWF SHOW A 500 MB TROUGH OVER THE LOWER
GREAT LAKES 12Z MON. THIS TROUGH DIGS ONTO THE EAST COAST 12Z TUE
WITH A RIDGE BUILDING INTO THE ROCKIES. UPPER PATTERN CHANGES LITTLE
12Z WED. ANOTHER SHORTWAVE DROPS INTO THE UPPER GREAT LAKES 12Z THU
WITH A SHOT OF COLD AIR COMING INTO THE AREA BY THE END OF THE
PERIOD. TEMPERATURES WILL STAY AROUND NORMAL THROUGH THE PERIOD AND
LAKE EFFECT SNOW SHOWERS WILL BE THE RULE WITH VERY LOW POPS THROUGH
THIS PERIOD. OVERALL...NO BIG CHANGES OR BIG EVENTS SEEN AND WILL BE
FAIRLY QUIET WEATHER.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1236 PM EST THU JAN 22 2015

SKIES HAVE CLEARED TODAY AND WILL CONTINUE TO STAY MOSTLY CLEAR INTO
TONIGHT BEFORE A CLIPPER SYSTEM MOVES THROUGH THE AREA. HAVE WIND
SHEAR AT ALL SITES WITH THE STRONG LOW LEVEL WINDS AHEAD OF THE
SYSTEM. ALL SITES WILL SEE LOWERING CONDITIONS TONIGHT INTO FRI
MORNING. PRECIPITATION IS EXPECTED TO START AS SNOW BEFORE BECOMING
A WINTRY MIX OF PRECIPITATION.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 429 AM EST THU JAN 22 2015

A HIGH PRESSURE RIDGE WILL QUICKLY SLIDE EAST ACROSS THE UPPER
GREAT LAKES REGION THIS MORNING...STEADILY BACKING WINDS TO THE
SOUTHWEST. AS THE PRESSURE GRADIENT TIGHTENS THIS AFTERNOON AND
TONIGHT AHEAD OF A LOW PRESSURE SYSTEM MOVING THROUGH NORTHERN
MANITOBA AND NORTHERN ONTARIO...EXPECT SOUTHWESTERLY GALES OF
35-40KTS OVER PORTIONS OF WESTERN AND CENTRAL UPPER MICHIGAN. BASED
OFF THE STRENGTH OF THE WINDS JUST ABOVE THE SURFACE...WOULDN/T BE
SURPRISED TO SEE SOME 45KT GUSTS AT THE HIGHER PLATFORMS AROUND
ISLE ROYALE. THE GALE WARNING THAT IS IN PLACE LOOKS TO BE IN DECENT
SHAPE...ALTHOUGH DID EXPAND IT SOUTHWEST TO LSZ162. A COLD FRONT
ASSOCIATED WITH THE LOW WILL SWEEP SOUTHEAST ACROSS LAKE SUPERIOR
ON FRIDAY...SHIFTING THE WINDS TO THE NORTHWEST AND BRINGING AN END
TO THE GALES. BEHIND THE FRONT...EXPECT WINDS TO 25-30KTS BEFORE
SHIFTING MORE NORTHERLY BEHIND A SECONDARY TROUGH ON MOVING ACROSS
LAKE SUPERIOR ON SATURDAY. WINDS WILL DIMINISH BEHIND THE SECONDARY
TROUGH AS A HIGH PRESSURE RIDGE SHIFTS SOUTH INTO THE AREA
SATURDAY NIGHT. ANOTHER CLIPPER SYSTEM WILL MOVE OUT OF CANADA AND
THROUGH THE UPPER MISSISSIPPI VALLEY ON SATURDAY NIGHT AND THEN
SLIDE THROUGH WISCONSIN SUNDAY MORNING. THIS WILL KEEP WINDS UP TO
20KTS OUT OF THE NORTH-NORTHEAST. ANOTHER RIDGE WILL BUILD IN
BEHIND THIS CLIPPER AND KEEP WINDS 15KTS OR BELOW SUNDAY NIGHT INTO
MONDAY.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
  GALE WARNING FROM 6 PM EST /5 PM CST/ THIS EVENING TO 9 AM EST
     /8 AM CST/ FRIDAY FOR LSZ162-263-264.

LAKE MICHIGAN...
NONE.
&&

$$

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



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