Area Forecast Discussion
Issued by NWS Marquette, MI

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000
FXUS63 KMQT 270805
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
405 AM EDT SUN JUL 27 2014

.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 412 PM EDT SAT JUL 26 2014

MQT 88D REMAINS DOWN AT THIS TIME. THE LATEST INFORMATION IS THAT IT
COULD BE UP AS EARLY AS LATER TONIGHT...OR SOMETIME MONDAY IF
ADDITIONAL PARTS ARE NEEDED.

STRONG STORMS CONTINUE...MAINLY PULSING UP AND DOWN THIS AFTERNOON.
THE AREA OF CONCERN IS OVER THE E THIRD OF THE CWA. DCAPE VALUES
NEAR 1000J/KG HAVE BEEN NOTED S CENTRAL...ALONG WITH GOOD SHEAR. SO
FAR...REPORTS OF HEAVY RAIN HAVE COME IN ON US-2 NEAR GLADSTONE. THE
NEXT ROUND OF CLOUDS /ACROSS WI/ WILL CLIP S CENTRAL UPPER MI LATE
THIS AFTERNOON...WITH MOST LOCATIONS WAITING FOR THE MAIN LOW. THIS
LOW IS EASILY VISIBLE OFF THE 19Z SATELLITE IMAGERY...SPINNING SW OF
LAKE WINNIPEG. LINGERING LOW LEVEL MOISTURE FROM RAIN THAT HAS
FALLEN...AND SOME FOG STILL EVIDENT ACROSS MAINLY N CENTRAL AND E
LAKE SUPERIOR WILL LIKELY REMAIN...AND EXPAND OVERNIGHT OVER THE E
HALF OF UPPER MI.

LOOK FOR THE STACKED SFC-500MB LOW TO PUSH ACROSS NW MN AROUND
06Z...WITH THE NEXT ROUND OF SHOWERS AND THUNDERSTORMS OVER THE W
HALF OF UPPER MI. DID NOT DEVIATE MUCH FROM OUR INITIAL THINKING
OVERNIGHT. STORM TOTAL QPF OF AROUND A QUARTER TO HALF INCH WILL BE
POSSIBLE. AT THIS TIME WE ARE EXPECTING THE BEST CHANCE OF HIGHER
AMOUNTS OVER CENTRAL UPPER MI. OF COURSE...HIGHER AND LIGHTER
AMOUNTS WILL BE POSSIBLE...DUE TO THE CONVECTIVE NATURE OF SOME OF
THE SHOWERS AND THUNDERSTORMS. HIGHEST CAPES ARE OVER THE CENTRAL
CWA.

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 402 AM EDT SUN JUL 27 2014

A HIGHLY AMPLIFIED FLOW PATTERN WILL BE IN PLACE FOR MUCH OF THE
NEXT WEEK...LEADING TO OCCASIONAL PERIODS OF SHOWERS AND AFTERNOON
THUNDERSTORMS. THE SHORTWAVE CURRENTLY MOVING THROUGH NORTHERN
MINNESOTA WILL LEAD TO THE AMPLIFICATION OF THE UPPER LOW SPINNING
OVER NORTHERN QUEBEC TODAY AND TONIGHT. THIS UPPER LOW CENTER WILL
ROTATE AROUND OR JUST EAST OF THE JAMES BAY AREA THROUGH THIS
UPCOMING WORK WEEK BEFORE FINALLY LIFTING NORTHEAST NEXT WEEKEND.
DETERMINISTIC AND ENSEMBLE MEMBERS/MEANS SHOW STRONG SUPPORT FOR
THIS PATTERN THROUGH THE WEEK (WITH THE UPPER TROUGH AXIS
STRETCHING SOUTH THROUGH THE EASTERN GREAT LAKES AND THE
APPALACHIANS) BEFORE GRADUALLY WEAKENING AND LIFTING NORTH HEADING
INTO THE FIRST WEEK OF AUGUST. WITH THE STRONG RIDGE OVER THE
ROCKIES...THE UPPER GREAT LAKES REGION WILL BE UNDER NORTHWEST FLOW
ALOFT THROUGH THE WEEK. THUS...EXPECT SEVERAL WAVES TO DROP
SOUTHEAST THROUGH THE REGION OVER THIS WEEK...LEADING TO SEVERAL
OPPORTUNITIES FOR SHOWERS AND AFTERNOON/EVENING THUNDERSTORMS.
ALTHOUGH TIMING THESE WAVES IS TRADITIONALLY DIFFICULT IN NORTHWEST
FLOW...THE MODELS SEEM TO HAVE A DECENT AGREEMENT ON THESE SUBTLE
WAVES THROUGH MID WEEK AND LEADS TO GREATER CONFIDENCE ON THE
TIMING. IN ADDITION...850MB TEMPERATURES FOR THE UPCOMING WEEK WILL
BE BETWEEN 4-12C WITH THE COLDEST VALUES ON MONDAY AND THEN A
GRADUAL WARM-UP TO THROUGH THE WEEK. THIS WILL LEAD TO BELOW NORMAL
TEMPERATURES ON MONDAY (HIGHS GENERALLY IN THE MID 60S TO LOWER 70S
AND AROUND 5-10 DEGREES BELOW NORMAL) BEFORE SLOWLY WARMING TOWARDS
NORMAL OR SLIGHTLY BELOW NORMAL VALUES BY NEXT WEEKEND.

MONDAY LOOKS TO BE THE DRIEST DAY...EVEN THOUGH A WEAK SHORTWAVE
ROTATES THROUGH DURING THE MORNING HOURS. THIS DRIER PERIOD WILL BE
SUPPORTED BY DRIER AIR ASSOCIATED WITH THE EASTERN EDGE OF A HIGH
PRESSURE RIDGE FROM A HIGH IN THE DAKOTAS. SOME LINGERING MOISTURE
WILL LIKELY LEAD TO SOME DIURNAL CU AWAY FROM LAKE SUPERIOR AND THE
NORTHERLY FLOW OFF THE LAKE. THE NEXT WEAK WAVE DIVES SOUTHEAST FROM
NORTHWESTERN ONTARIO ON MONDAY NIGHT AND MAY PRODUCE A FEW SHOWERS
OVER THE NORTHWEST HALF/THIRD OF THE CWA. LOSS OF DIURNAL HEATING
LIKELY WON/T HELP THE SHOWERS PUSHING SOUTHEAST OFF THE LAND AND
OVER LAKE SUPERIOR ON MONDAY NIGHT...BUT FEEL CONTINUING SLIGHT
CHANCES FOR RAIN IS REASONABLE.

A MUCH STRONGER SHORTWAVE TROUGH WILL SWEEP ACROSS THE UPPER GREAT
LAKES REGION TUESDAY AND LEAD TO THE BEST OPPORTUNITY FOR WIDESPREAD
SHOWER/THUNDERSTORM ACTIVITY DURING THE UPCOMING WORK WEEK. A WEAK
AREA OF LOW PRESSURE WILL LIKELY DEVELOP WITH THIS WAVE OVER
NORTHERN ONTARIO AND SWEEP A SURFACE TROUGH ACROSS THE AREA TUESDAY
AFTERNOON. BASED ON THE CONSISTENCY IN THE MODELS WITH THIS
FEATURE...WILL TREND POPS UP TO HIGH END CHANCES OVER INLAND AREAS
DUE TO DAYTIME HEATING (AND ESPECIALLY OVER THE CENTRAL/EAST WHERE
THE BEST FORCING FROM THE SHORTWAVE WILL BE LOCATED). MU/ML CAPE
VALUES INCREASE GOING INTO THE AFTERNOON (GENERALLY 250-1000
J/KG)...SO PREVIOUS SHIFT/S IDEA OF STARTING THUNDER CHANCES FOR THE
AFTERNOON HOURS IS REASONABLE. UNIDIRECTIONAL 0-6KM SHEAR OF
20-25KTS AND A FAIRLY TALL/SKINNY CAPE (NCAPE VALUES 0.06-0.1)
SHOULD LIMIT ANY SEVERE WEATHER POTENTIAL. GREATEST CONCERN WOULD BE
BRIEF HEAVY RAIN IN THE STRONGER SHOWERS/THUNDERSTORMS...BUT THE
UNFAVORABLE NORTHWEST FLOW KEEPING PWATS GENERALLY BELOW 1.0 INCH
(SLIGHTLY BELOW NORMAL FOR LATE JULY) SHOULD KEEP AMOUNTS FROM
GETTING MUCH ABOVE 0.5IN.

EXPECT A DRYING TREND THROUGH TUESDAY NIGHT AS THE SHORTWAVE
DEPARTS AND AREA COMES BACK UNDER THE INFLUENCE OF THE WEAK SURFACE
RIDGE. THIS SHOULD CONTINUE THROUGH MUCH OF WEDNESDAY...BUT DIURNAL
HEATING AND AN APPROACHING SHORTWAVE FOR WEDNESDAY NIGHT MAY BE
ENOUGH TO PRODUCE A FEW SHOWERS AND AN ISOLATED THUNDERSTORMS OVER
INTERIOR WEST/CENTRAL LOCATIONS ON WEDNESDAY AFTERNOON. WILL JUST
SHOW SLIGHT CHANCES DURING THE AFTERNOON HOURS FOR THAT POTENTIAL.
THAT NEXT SHORTWAVE WILL LIKELY SWEEP THROUGH WEDNESDAY NIGHT...BUT
LACK OF DIURNAL HEATING AND MORE MARGINAL MID LEVEL MOISTURE LEADS
TO LIMITED CONFIDENCE OF SHOWER POTENTIAL.

CONFIDENCE WANES AFTER WEDNESDAY NIGHT...AS THE BEST UPPER LEVEL
ENERGY BECOMES FOCUSED CLOSER TO THE UPPER LOW NEAR JAMES BAY
THROUGH THE REST OF THE FORECAST PERIOD AND THE WEAK SURFACE RIDGE
CONTINUES TO COVER THE AREA. WILL ATTEMPT TO FOLLOW A GENERAL MODEL
CONSENSUS (SLIGHT AND LOW CHANCE POPS) FOR THE REST OF THE PERIOD
AND TRY TO SHOW SOME TIMING OF DIURNALLY DRIVEN SHOWERS OVER THE
LAND AREAS.
&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 122 AM EDT SUN JUL 27 2014

EXPECT VFR CONDITIONS EARLY IN THE TAF PERIOD TO GIVE WAY TO MVFR
CONDITIONS AS SOME SCT SHRA...AND ISOLD TSRA IN KCMX AREA..ARRIVE IN
ADVANCE OF DISTURBANCE MOVING INTO MN AND FOG DVLPS IN THE PRESENCE
OF DIURNAL COOLING. CONDITIONS ARE LIKELY TO DETERIORATE TO IFR ON
SUN MRNG WITH WSHFT TO AN UPSLOPE COMPONENT OFF LK SUP. A STEADY NNE
WIND WL TAP DRIER AIR...WHICH SHOULD LEAD TO IMPROVING CONDITIONS
DURING THE AFTN. WITH A MORE FVRBL UPSLOPE WIND COMPONENT...SAW WL
BE THE LAST TO SEE IMPROVEMENT.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 322 PM EDT SAT JUL 26 2014

EARLY EVENING UPDATE...BASED ON SHIP OBS...VISIBLE SATELLITE IMAGERY
AND WEBCAMS NEAR THE LAKE SHORE...ISSUED A DENSE FOG ADVISORY FOR
MOST OF EASTERN AND NORTH CENTRAL LAKE SUPERIOR. LATER SHIFTS WILL
LIKELY HAVE TO EXTEND THE ADVISORY TO THE SOUTH CENTRAL AND PERHAPS
PORTIONS OF THE WESTERN LAKE.

WINDS AROUND 25KTS OR LESS WILL REMAIN THROUGH THE PERIOD. A TROUGH
ACROSS THE UPPER GREAT LAKES REGION WILL EXIT TO THE LOWER GREAT
LAKES ON SUNDAY...BEFORE DEEPENING MONDAY AND MONDAY NIGHT ACROSS
THE NEW ENGLAND STATES.  IN THE MEANTIME...LOOK FOR A LARGE HIGH
ACROSS SOUTH CENTRAL CANADA THROUGH THE NORTHERN PLAINS SUNDAY
NIGHT. IT WILL WEAKEN SLIGHTLY ACROSS THIS SAME AREA TUESDAY THROUGH
THURSDAY...WHILE A WEAK TROUGH OF LOW PRESSURE DIPS ACROSS ONTARIO
MONDAY NIGHT...AND LAKE SUPERIOR ON TUESDAY.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
  DENSE FOG ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR LSZ264-266-
     267.

  DENSE FOG ADVISORY FROM 8 AM THIS MORNING TO 2 PM EDT THIS
     AFTERNOON FOR LSZ244>248-265.

  DENSE FOG ADVISORY UNTIL 5 PM EDT THIS AFTERNOON FOR LSZ249>251.

LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...KF
LONG TERM...SRF
AVIATION...KC
MARINE...KF/KC






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