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 260932
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
532 AM EDT SUN OCT 26 2014

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 316 AM EDT SUN OCT 26 2014

UPPER AIR PATTERN CONSISTS OF A 500 MB CLOSED LOW SOUTH OF JAMES BAY
WITH A RIDGE OVER THE CENTRAL U.S. THIS MORNING. THE RIDGE MOVES
INTO THE UPPER GREAT LAKES BY THIS EVENING. THE TROUGH IN THE
PACIFIC NW THIS MORNING WILL HEAD EAST INTO THE NORTHERN ROCKIES
LATE TONIGHT. NAM BRINGS IN SOME 850-500 MB Q-VECTOR CONVERGENCE AND
DEEPER MOISTURE LATE TONIGHT ACROSS THE CWA. NAM SHOWS SOME
ISENTROPIC LIFT AND MOISTURE ON I290K-I305K SURFACES LATE TONIGHT
OVERSPREADING MOST OF THE CWA WITH DRY LOW LEVEL AIR REMAINING OVER
THE EAST.

DID NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST. DRY AIR OVER
THE EAST IS A CONCERN AND HELD OFF ON POPS OVER THE EASTERN CWA
TONIGHT AND WENT DRY. KEPT IN CHANCE POPS OVER THE WEST HALF TONIGHT
WITH DRY AIR IN THE LOW LEVELS REMAINING INTO THIS EVENING. KEPT IN
THUNDER POSSIBILITY FOR LATE TONIGHT AS THERE IS SOME INSTABILITY
ALOFT.

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 531 AM EDT SUN OCT 26 2014

SHAPING UP TO BE AN ACTIVE WEATHER WEEK OVER UPR MICHIGAN. TEMPS
WILL START OUT AROUND OR EVEN ABOVE NORMAL...BUT BY WEEKS END
WILL TREND WELL BELOW NORMAL AS DEEP TROUGHING BRINGS IN THE COLDEST
AIR OF THE FALL THUS FAR. SNOW SHOWERS LOOKING LIKE A PRETTY GOOD BET
BY THURSDAY NIGHT AND INTO FRIDAY. IF THERE ARE SNOW ACCUMS...THEY
WOULD ONLY BE IN THE FAVORED LAKE EFFECT AREAS.

UPPER LEVEL TROUGH OVER PACIFIC NORTHWEST MAKES THE NORTHERN PLAINS
BY LATE MONDAY. ASSOCIATED DOUBLE BARRELLED SFC LOW REACHES THE
UPPER MISSISSIPPI RIVER VALLEY ON MONDAY AFTN. AHEAD OF THE TROUGH
AND THE SFC LOWS/TROUGH AS WELL...EMBEDDED SHORTWAVE ENERGY AND
ADDITIONAL LIFT FM DIFFLUENCE FM H3 JET COMBINES WITH SHARP H85
THETA-E ADVECTION TO KICK OFF AREA OF SHOWERS AND EVEN SCATTERED
TSRA /1-6KM MUCAPE AROUND 1000 J/KG/ OVER MAINLY CNTRL AND EAST
CWA THROUGH MID MONDAY AFTN. GIVEN THE DEGREE OF INSTABILITY...AND
EFFECTIVE SHEAR OVER 30 KTS FORECAST THROUGH 15Z...THINK THERE IS A
SMALL RISK OF AN ISOLD HAILER. SPC SREF 3HR CALIBRATED SEVERE
THUNDERSTORM PROBABILITIES ONLY CHECKING IN AT 5-10 PCT...BUT DOES
APPEAR TO BE TRENDING HIGHER OVER LAST FEW SREF RUNS. SPC HAS AREA IN
GENERAL THUNDER...BUT THE 5 PCT/MARGINAL RISK FOR SEVERE IS WELL TO
SOUTH OF HERE. WILL NOT PUT ANY MENTION IN THE HWO/EHWO THOUGH AS IT
WOULD BE VERY REMOTE CHACE. DAYSHIFT CAN TAKE ANOTHER LOOK.

SCATTERED SHOWERS AND TSRA SHOULD EXIT BY MONDAY EVENING TO THE
EAST. REST OF THE EVENING MAY FEATURE LULL IN RAIN. SOUNDINGS
INDICATE A LOT OF MOISTURE THROUGH H85 BUT LITTLE FORCING WITHIN THE
MOIST LAYER. MAY SEE FOG OR DRIZZLE AT THAT TIME. RAIN CHANCES RAMP
UP AGAIN OVERNIGHT MONDAY NIGHT...ESPECIALLY NORTHWEST AND EASTERN
CWA AS THOSE AREAS WILL BE IMPACTED BY ADDITIONAL LIFT AHEAD OF THE
PRIMARY TROUGH AND ON EDGE OF GREATER LOW-LEVEL MOISTURE ON FRINGE
OF SW-NE LOW-LEVEL JET /EASTERN CWA/ AND WITHIN AREA OF DEEP
CONVERGENCE ALONG SFC TROUGH AXIS AND IN AREA OF STRONGER LIFT DUE
TO H7-H5 Q-VECTOR CONVERGENCE FM THE SHORTWAVE /NORTHWEST CWA/.
DUE TO THE CLOUDS AND LIMITED MIXING...TEMPERATURES WILL NOT VARY
TOO MUCH FM THE DAYTIME ON MONDAY TO THE OVERNIGHT HOURS ON MONDAY
NIGHT. MID 50S AT BEST ON MONDAY OVER THE SCNTRL AND MAINLY 40S ON
MONDAY NIGHT.

UPPER TROUGH AXIS IS OVERHEAD UPR MICHIGAN ON TUESDAY WHICH BRINGS
DRY SLOT INTO PLAY. LOW-LEVEL DRYING BEST OVER SCNTRL WHERE TEMPS
SHOULD PUSH MID 50S. ELSEWHERE...BEST CHANCE OF RAIN WILL BE IN THE
MORNING DUE TO 1000-850MB MOIST CONVERGENCE AND H7-H5 Q-VECTOR
CONVERGENCE. STILL SINCE THE BULK OF H85 THETA-E ADVECTION IS WELL
TO THE EAST OF CWA...NOT EXPECING ANY TSRA OR MODERATE TO HEAVY RAIN
BUT LIGHTER SHOWERS WITH AGAIN POSSIBLE DRIZZLE BEFORE UNFAVORABLE
WEST BLYR FLOW SCOURS THAT OUT IN THE AFTN. HIGH TEMPS IN THE 50S.
WEST WINDS MAY BE QUITE GUSTY OVER LK SUPERIOR AND ON THE KEWEENAW
WHERE NEAR ADVY LEVEL GUSTS TO 45 MPH MAY OCCUR IN THE AFTN.

UPPER TROUGH AND DEEPENING SFC LOW MOVES EAST OF UPPER GREAT LAKES
BY WEDNESDAY MORNING ALLOWING COLDER AIR TO FLOW IN ON NNW-N WINDS.
H85 TEMPS DOWN TO -4C TO -6C WITH SOUNDINGS SHOWING MOST OF THE
MOISTURE AT H85 OR BLO. MAY BE ENOUGH LARGER SCALE SUPPORT /HIGHER RH
TO H7/ AROUND INTO WEDNESDAY MORNING TO HAVE SOME LAKE ENHANCED RAIN
OR RAIN/SNOW SHOWERS GIVEN DELTA T/S OVER 10C. HOWEVER...AS WEDNESDAY
GOES ON THERE SEEMS TO NOT BE ENOUGH COLD AIR TO KEEP PURE LK EFFECT
GOING AS DELTA T/S STAY BLO 13C. CYCLONIC FLOW IS LACKING BY WED AFTN
AS WELL SO EXPECT POPS TO TREND DOWN THROUGH THE DAY. CANNOT RULE OUT
ISOLD RAIN AND SNOW SHOWERS ALL THE WAY THROUGH THE AFTN THOUGH. HIGH
TEMPS ON WEDNESDAY ONLY TOPPING OUT AROUND 40 DEGREES FOR HIGHER
TERRAIN NEAR LK SUPERIOR AND IN THE 40S ELSEWHERE. WINDS MAY BE
STRONG AND GUSTY TUESDAY NIGHT INTO WEDNESDAY MORNING AS WINDS SHIFT
NORTHWEST IN WAKE OF THE LOW...ESPECIALLY NEAR LK SUPERIOR OVER THE
CNTRL AND EAST CWA. ANOTHER LULL EXPECTED INTO WEDNESDAY NIGHT AND
POSSIBLY THURSDAY MORNING THOUGH THERE MAY BE SCATTERED SHOWERS
TRYING TO DEVELOP WITHIN WEAK WARM AIR ADVECTION REGIME AHEAD OF
STRONG REINFORCING SHORTWAVE.

THAT SHORTWAVE DIVES DOWN THURSDAY AFTN OR THURSDAY EVENING...BUCKLING
THE UPPER LEVEL FLOW FM WNW TO NNW-NW AND BRINGING IN A CHILLY AIRMASS
FOR HALLOWEEN WITH H85 TEMPS BLO -10C. ECMWF AND GFS DIFFER IN HOW
MUCH LARGER SCALE SUPPORT/MID-LEVEL MOISTURE WHICH WOULD ENHANCE THE
LAKE EFFECT RAIN/SNOW TO SNOW SHOWERS. CONSENSUS OF MODELS MISS THE
BOAT FOR LK EFFECT TYPE REGIMES AND HAD TO RAISE THOSE POPS AND
ASSOCIATED SKY COVER. KEPT POPS SIMILAR TO PREVIOUS FORECAST. GIVEN
MOISTURE TO AT LEAST H85 AND CYCLONIC SFC FLOW AND DELTA T/S OVER
15C...WILL SEE SCATTERED LAKE EFFECT SNOW SHOWERS LATER THURSDAY
NIGHT INTO FRIDAY. HIGHS ON FRIDAY ONLY IN THE LOW 30S NORTH TO
AROUND 40 SOUTH SHOULD LEAD TO SOME MINOR SNOW ACCUMS FOR THE FAVORED
LAKE EFFECT AREAS OF THE NORTH IF THERE ARE ANY HEAVIER SNOW SHOWERS.
GFS SOUNDINGS SHOW WELL MIXED BLYR OVER H7 WHICH WOULD RESULT IN
SOLID GALES 35-40 KTS ON LK SUPERIOR AND NEAR ADVY LEVEL WINDS NEAR
LK SUPERIOR INTO FRIDAY MORNING. GUSTY WINDS SHOULD DIMINISH FRIDAY
AFTN AND EVENING AS SFC RIDGE NEARS. KEPT SMALL CHANCES FOR LAKE
EFFECT RAIN/SNOW SHOWERS INTO SATURDAY THOUGH AS WINDS STAY OUT OF
THE NW...THOUGH IT DOES APPEAR THAT COLD AIR SHOT MODERATES REST OF
NEXT WEEKEND. &&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 116 AM EDT SUN OCT 26 2014

UNDER A DRY AIR MASS...VFR CONDITIONS WILL PREVAIL AT KIWD/KCMX/KSAW
THRU THIS FCST PERIOD. WINDS WILL CONTINUE TO RELAX AS SFC HIGH PRES
RIDGE APPROACHES...ARRIVING OVER THE AREA DURING THE MID AND LATE
AFTN HRS. PRES GRADIENT WILL QUICKLY TIGHTEN TONIGHT. WITH LOW-LEVEL
JET RAMPING UP OVER NOCTURNAL INVERSION...LLWS MAY NEED TO BE
CONSIDERED IN LATER FCSTS.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 316 AM EDT SUN OCT 26 2014

AS STRONG LOW PRESSURE SYSTEM MOVES SLOWLY WEST TO EAST OVER
NORTHERN ONTARIO...SW TO W GALES OVER 35 KTS ARE EXPECTED INTO
THIS EVENING...MAINLY CENTRAL AND EAST LAKE SUPERIOR. NW WINDS OF 20
TO 30 KTS WILL LINGER INTO SUNDAY MORNING IN WAKE OF THE LOW AND
BEFORE SFC RIDGE CROSSES THE UPPER GREAT LAKES REGION. AFTER A BRIEF
PERIOD WITH WINDS LESS THAN 20 KTS WITH THE HIGH PRESSURE...SE WINDS
INCREASE TO 30 KTS OVER MAINLY EAST LAKE SUPERIOR ON MONDAY AHEAD OF
AN APPROACHING LOW PRESSURE SYSTEM. ONCE THIS LOW MOVES TO THE EAST
OF LAKE SUPERIOR ON TUESDAY...WEST WINDS TO 30 KTS AND POSSIBLY UP
TO GALE FORCE OF 35 KTS WILL DEVELOP LATE TUESDAY INTO TUESDAY
NIGHT. WINDS WILL THEN SHIFT NORTHWEST AND STAY UP TO 30 KTS INTO
WEDNESDAY...BEFORE GRADUALLY DIMINISHING TO LESS THAN 25 KTS BY
THURSDAY.
&&

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

$$

SHORT TERM...07
LONG TERM...JLA
AVIATION...ROLFSON
MARINE...07








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