Area Forecast Discussion
Issued by NWS Marquette, MI

Home | Current Version | Previous Version | Text Only | 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 260605
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
105 AM EST MON JAN 26 2015

.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 244 PM EST SUN JAN 25 2015

THE UPPER GREAT LAKES IS BETWEEN CLIPPER SYSTEMS THIS
AFTERNOON...WITH THE FIRST ONE MOVING INTO THE OHIO RIVER VALLEY AT
THIS TIME...WITH THE SECOND ONE ROUNDING THE UPPER RIDGE OVER THE
WESTERN CONUS. BETWEEN THESE TWO CLIPPERS...AN AREA OF HIGH PRESSURE
IS LOCATED OVER NORTHERN ONTARIO AND IS STRETCHING A RIDGE OVER THE
UPPER GREAT LAKES REGION. THIS RIDGE HAS LED TO WEAKENING WINDS OVER
THE CWA THROUGH THE DAY TODAY AND WHEN COMBINED WITH THE LOWERING
SUBSIDENCE INVERSION (SEEN ON KMQT VAD)...HAS DIMINISHED THE LAKE
EFFECT SNOW SHOWERS OVER THE AREA FROM THIS MORNING. BUT THERE ARE
STILL SNOW SHOWERS OVER THE NORTH CENTRAL AND KEWEENAW. THESE SNOW
SHOWERS WILL CONTINUE TO SLOWLY DIMINISH THROUGH THE EVENING AND
THEN WHAT IS LEFT OVER WILL SHIFT NORTH OVER LAKE SUPERIOR AS THE
SOUTHERLY WINDS DEVELOP AHEAD OF THE NEXT CLIPPER SYSTEM.

THAT NEXT CLIPPER SYSTEM (CURRENTLY MOVING THROUGH NORTHERN
SASKATCHEWAN) WILL DROP SOUTHEAST AND THROUGH THE AREA LATE TONIGHT
AND MONDAY. THERE ARE TWO EMBEDDED WAVES OF ENERGY ASSOCIATED WITH
THIS CLIPPER SYSTEM THAT WILL AFFECT THE AREA. THE FIRST WAVE WILL
MOVE INTO THE MINNESOTA ARROWHEAD SHORTLY AFTER 06Z TONIGHT AND THEN
QUICKLY DIVE SOUTHEAST ACROSS WESTERN LAKE SUPERIOR AND NORTHWEST
WISCONSIN BY 12Z MONDAY. THE SECOND WAVE WILL TRACK A TOUCH FARTHER
TO THE NORTHEAST AND WILL BE ASSOCIATED WITH THE WEAKENING SURFACE
LOW MOVING ACROSS WESTERN LAKE SUPERIOR MONDAY AFTERNOON. THERE HAS
DEFINITELY BEEN A SOUTHWEST TREND IN THE TRACK OF THESE WAVES OVER
THE LAST 24HRS...SO HAVE CONTINUED THAT TREND WITH THIS FORECAST.
WITH THE TRACK OF THE TWO WAVES...WILL SHOW INCREASING POPS OVER THE
WEST-SOUTHWEST HALF OF THE CWA OVERNIGHT TONIGHT (HIGHEST NEAR
IRONWOOD). BASED OFF THE TRACK OF THE SHORTWAVE AND BEST 850-500MB
WARM AIR ADVECTION AND Q-VECTOR CONVERGENCE...THINK THE BEST
PRECIPITATION WILL BE SOUTHWEST OF THE CWA BUT STILL SHOULD SEE 1-2
INCHES OF SNOW OVER THE WESTERN THIRD OF UPPER MICHIGAN THROUGH
MONDAY MORNING. THEN AS THE SECOND WAVE MOVES THROUGH LATE MONDAY
MORNING THROUGH EARLY EVENING...SHOULD SEE A MORE BROAD/LIGHT SNOW
SPREADING SOUTHEAST OVER THE MUCH OF THE REST OF THE CWA. ONCE
AGAIN...SNOWFALL AMOUNTS SHOULD BE LIGHT WITH THIS SECOND WAVE AND
GENERALLY UNDER AN INCH.

THERE IS ONE OTHER ITEM OF CONCERN WITH THIS CLIPPER SYSTEM...LAKE
EFFECT/ENHANCED SNOW OFF LAKE MICHIGAN. AS THE SOUTH-SOUTHEAST FLOW
DEVELOPS OVER THE LAKE LATE TONIGHT AND MONDAY MORNING...875MB TEMPS
ARE STILL HOVERING AROUND -12 TO -13C AND PROVIDING DECENT DELTA-T
VALUES OVER THE LAKE. MODELS ARE INDICATING THERE BEING ENOUGH DRY
AIR AND SUBSIDENCE IN PLACE MONDAY MORNING TO LIMIT SNOW
DEVELOPMENT...BUT AS THE DEEPER MOISTURE ARRIVES IN THE AFTERNOON
WITH THE SECOND WAVE SHOULD SEE THE SNOW DEVELOP. THERE IS A LITTLE
BIT OF A CONCERN IN THE SHEAR IN THE CLOUD LAYER (SOUTHEAST WINDS AT
THE SURFACE...SOUTH MID CLOUD...AND SOUTHWEST AT THE TOP OF THE
CLOUD)...WHICH COULD HELP LIMIT THE INTENSITY OF THE SNOW. BASED OFF
THE CONSISTENCY IN THE HIGHER RESOLUTION MODELS...DID TREND THE POPS
UP TO LIKELY-DEFINITE VALUES OVER DELTA/SCHOOLCRAFT COUNTIES (AND
EVEN WESTERN ALGER) TO HIGHLIGHT THAT LAKE EFFECT SNOW POTENTIAL.
CURRENTLY HAVE AMOUNTS IN THE 1-2 INCH RANGE...BUT THERE COULD BE A
NARROW BAND OF HIGHER AMOUNTS DEPENDING ON THE EXACT LOCATION OF
WHERE THINGS SETUP.

CLEARING INITIALLY OVER PARTS OF THE AREA WILL LEAD TO A QUICK FALL
IN TEMPS THIS EVENING BEFORE SOUTHERLY FLOW AND HIGH CLOUDS
DEVELOP/MOVE OVER THE AREA OVERNIGHT. WITH DEWPOINTS IN THE MID-
LOWER SINGLE DIGITS ABOVE ZERO IN AREAS THAT CLEARED...HAVE USED
THAT AS A STARTING POINT AND WENT WITH LOWS AROUND 4-7 DEGREES BELOW
THAT. IT SHOULD BE SHORT LIVED LOWS...AS TEMPERATURES SLOWLY RISE
FROM WEST TO EAST AS THE CLOUDS INCREASE. HIGHS ON MONDAY SHOULD BE
AROUND OR SLIGHTLY ABOVE NORMAL (20S).

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 105 AM EST MON JAN 26 2015

WITH THE 500MB LOW AND THE AXIS OF THE 500MB TROUGH SHIFTED OVER THE
NEW ENGLAND STATES TUESDAY...THE RIDGE CURRENTLY OVER THE W HALF OF
THE NATION WILL BE ABLE TO SHIFT ACROSS THE CENTRAL PLAINS AND UPPER
GREAT LAKES TUESDAY INTO EARLY WEDNESDAY.

AT THE SFC...A RIDGE WILL BE ABLE TO SLIDE ACROSS LAKE SUPERIOR
TUESDAY /EXTENDING FROM MN UP THROUGH NEWFOUNDLAND/...WHICH WILL
LINGER INTO TUESDAY NIGHT AS THE MAIN AREA OF HIGH PRESSURE PUSHES
INTO THE OHIO VALLEY TUESDAY NIGHT INTO WEDNESDAY. THE RESULT WILL
BE A DRY PERIOD AT LEAST UNTIL MID DAY WEDNESDAY...ALTHOUGH THERE
MAY STILL BE SOME CLOUDS LINGERING/STUCK BELOW THE 850-900MB
SUBSIDENCE INVERSION. TRICKY CLOUD COVER FCST FOR THIS PERIOD.

WEDNESDAY LOOK TO BE THE LAST WARM DAY IN A WHILE...WITH
TEMPERATURES NEAR FREEZING. 850MB TEMPS ON S FLOW WILL RISE TO -1 TO
-4C THROUGH THE DAYTIME HOURS AS THICKER CLOUDS INVADE FROM THE NW.

AN ELONGATED AREA OF LOW PRESSURE OVER THE N AND CENTRAL PLAINS
WEDNESDAY MORNING WILL EDGE E ACROSS IL AND IN THURSDAY
MORNING...AND OFF TO THE LOWER GREAT LAKES AND OFF THE MID ATLANTIC
STATES FRIDAY. THIS WILL BRING A TROUGH ACROSS OUR AREA WEDNESDAY
NIGHT THROUGH THURSDAY EVENING...WHICH WILL BE ENHANCED BY THE
SUPPRESSION OF THE 500MB RIDGE WEDNESDAY EVENING AND THURSDAY. LOOK
FOR A WIDESPREAD 2-5IN OF SNOW WITH SLR VALUES AROUND 15:1. EXPECT
THE HIGHER VALUES OVER THE N HALF OF UPPER MI AS IT WILL LIKELY TAKE
UNTIL LATE AFTERNOON/EARLY EVENING FOR SNOW TO BEGIN S CENTRAL. WILL
NOT GO QUITE AS QUICK WITH THE INVADING PRECIP AS THE 00Z NAM...BUT
A BLENDED SOLUTION SOUNDS REASONABLE. A WINTER WX ADVISORY MAY BE
NEEDED IF THE 2-5IN CAN FALL IN A 12HR PERIOD. WILL CONTINUE TO LOOK
INTO THIS FOR POSSIBLE POSTING OF HEADLINES ON TUESDAY...AND
HIGHLIGHT THE POTENTIAL FOR LIGHT TO MODERATE SNOW IN THE HWO.

N FLOW BEHIND THE EXITING SFC TROUGH THURSDAY AFTERNOON WILL BE THE
START OF OUR COOL DOWN...WITH 850MB TEMPS FALLING TO -8 TO -10C.
WHILE NOT QUITE OPTIMAL FOR LAKE EFFECT YET...SOME LAKE ENHANCEMENT
WILL BE LIKELY ALONG THE UPSLOPE N SNOWBELTS ALONG LAKE SUPERIOR
THURSDAY AS THE SFC LOW EXITS TO THE LOWER GREAT LAKES/PENNSYLVANIA
FRIDAY EVENING.

DESPITE SFC-500MB RIDGING ON FRIDAY...A FEW LINGERING LES WILL
REMAIN ALONG THE LAKE SUPERIOR SHORELINES. DON/T EXPECT MUCH IN THE
WAY OF ACCUMULATIONS AS THE MOISTURE IS AGAIN TRAPPED BELOW 850MB.
BUT WILL THE MOISTURE LAYER IN THE DGZ /850MB TEMPS OF -15 TO
-17C/...SOME LIGHT ACCUMULATIONS WILL BE POSSIBLE.

SLIGHTLY WARMER AIR WILL PUSH IN THROUGH EARLY SATURDAY MORNING AS
THE SFC RIDGE EXITS TO THE LOWER GREAT LAKES...AND IN ADVANCE OF LOW
PRESSURE DEVELOPING NEARING FROM THE N PLAINS STATES.

SOME OF THE COLDEST AIR OF THE SEASON WILL PUSH INTO THE UPPER GREAT
LAKES SATURDAY AFTERNOON ON. THERE CONTINUES TO BE SOME TIMING
ISSUES ON THE ORDER OF AROUND 6HRS...WHICH IS PRETTY MINOR THIS FAR
OUT IN THE FCST...AND A BLENDED SOLUTION LOOKS REASONABLE. 850MB
TEMPS OF -20 TO -30C WILL SETTLE IN SUNDAY AFTERNOON AS THE SFC LOW
EXITS AND THE MAIN 500MB TROUGH PUSHES ACROSS THE UPPER GREAT LAKES.
LOOK FOR FINE LES THAT WILL BE GOOD AT REDUCING VIS...ESPECIALLY IF
THE STRONGER NW WINDS OF THE 25/12Z ECMWF ARE CORRECT/.
&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1227 AM EST MON JAN 26 2015

A CLIPPER SYSTEM DROPPING SE THROUGH SRN MANITOBA WILL MOVE ACROSS
THE AREA OVERNIGHT INTO MONDAY. VFR CONDITIONS WILL GIVE WAY TO
GRADUALLY LOWERING CEILINGS AHEAD OF THE SYSTEM AND THEN SNOW MOVING
IN AT KIWD JUST AFT 12Z...AT KCMX LATE MON MORNING AND THEN AT KSAW
EARLY MON AFTERNOON. EXPECT IFR VSBYS TO AFFECT KIWD FROM MON MORNING
INTO EARLY AFTERNOON AND THEN IFR VBSYS WILL SPREAD INTO KCMX AND
KSAW LATE MON AFTERNOON INTO MON EVENING AS MOISTURE DEEPENS OVER THE
NW AND NCNTRL PORTION OF THE U.P. SOME IMPROVEMENT IN VSBY IS
EXPECTED AT KIWD LATE MONDAY AS BEST MOISTURE DEPARTS AND SNOW TAPERS
OFF.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 244 PM EST SUN JAN 25 2015

A HIGH PRESSURE RIDGE MOVING ACROSS LAKE SUPERIOR WILL CONTINUE TO
WEAKEN WINDS THROUGH THE EVENING HOURS...BEFORE INCREASING OUT OF
THE SOUTH THROUGH THE REST OF THE NIGHT AHEAD OF A CLIPPER SYSTEM.
THIS CLIPPER SYSTEM WILL MOVE SOUTHEAST THROUGH NORTHWEST WISCONSIN
WHILE WEAKENING. THE SOUTHERLY FLOW AHEAD OF THE CLIPPER WILL LEAD
TO WINDS OF 20-30KTS LATE TONIGHT INTO MONDAY. A HIGH PRESSURE
RIDGE BUILDING INTO THE UPPER GREAT LAKES REGION ON MONDAY NIGHT
WILL DIMINISH WINDS BELOW 15KTS BY LATE MONDAY NIGHT AND WILL
REMAIN THROUGH TUESDAY. A LOW PRESSURE SYSTEM DEVELOPING IN THE
NORTHERN/CENTRAL PLAINS ON TUESDAY NIGHT WILL SHIFT EAST INTO THE
MID MISSISSIPPI VALLEY BY WEDNESDAY NIGHT...SHIFTING A TROUGH EAST
ACROSS THE UPPER GREAT LAKES REGION. WINDS ASSOCIATED WITH THIS
TROUGH WILL LIKELY STAY BELOW 25KTS.
&&

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

$$

SHORT TERM...SRF
LONG TERM...KF
AVIATION...VOSS
MARINE...SRF


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