Area Forecast Discussion
Issued by NWS Marquette, MI

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000
FXUS63 KMQT 211149
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
749 AM EDT MON JUL 21 2014

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 535 AM EDT MON JUL 21 2014

WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A RIDGE EXTENDING FROM NRN
MEXICO INTO THE WCNTRL PLAINS. A SHORTWAVE WAS MOVING ACROSS NRN
MANITOBA. ASSOCIATED SFC LOW WAS OVER NE MANITOBA WITH TRAILING COLD
FRONT EXTENDING THRU THE WRN PORTION OF NRN ONTARIO AND THEN SW INTO
NW MN AND ND. WITH STRONGER 850MB FLOW IN RESPONSE TO SHORTWAVE
CONFINED MOSTLY TO NRN ONTARIO...SHRA/TSRA HAVE BEEN OCCURRING
MAINLY IN NRN ONTARIO OVERNIGHT WITH SRN END OF CONVECTION AT TIMES
ACROSS THE BORDER IN FAR NRN MN. RECENT RADAR IMAGERY SHOWS A FEW
SHRA NOW DEVELOPING OVER LAKE SUPERIOR BTWN THE KEWEENAW AND ISLE
ROYALE. WELL OUT TO THE W...A SHORTWAVE WAS LIFTING OUT OF THE GREAT
BASIN. THIS FEATURE WILL TRIGGER SVR STORMS THIS AFTN OVER ND WITH
STORMS EVOLVING INTO AN MCS THAT WILL AFFECT THE UPPER LAKES LATE
TONIGHT/TUE.

AS TAIL END OF STRONGER 850MB FLOW SHIFTS E ACROSS LAKE SUPERIOR
THIS MORNING/EARLY AFTN...MAY SEE ISOLD SHRA/TSTMS SPREAD ACROSS
PORTIONS OF NW AND NCNTRL UPPER MI. RECENT SHRA DEVELOPMENT BTWN THE
KEWEENAW AND ISLE ROYALE PROVIDES SOME CONFIDENCE FOR THE POTENTIAL
OF ISOLD CONVECTION FARTHER E AS THE MORNING PROGRESSES. OVERNIGHT
HIGH RES RAPID REFRESH MODEL RUNS HAVE BEEN INSISTENT ON GREATER
COVERAGE OF CONVECTIVE DEVELOPMENT FARTHER S INTO UPPER MI THIS
MORNING. SEEMS OVERDONE...BUT WILL BE SOMETHING TO MONITOR. AS WIND
FIELDS WEAKEN THIS AFTN...LAKE BREEZE MAY SLIP ONSHORE OVER
PORTIONS OF NCNTL UPPER MI. IF SO...NOT OUT OF THE QUESTION THAT A
AN ISOLD TSTM OR TWO COULD DEVELOP ALONG THE BOUNDARY WITHIN
MOIST/UNSTABLE ENVIRONMENT. OTHERWISE...EXPECT PARTLY TO MOSTLY
SUNNY SKIES TODAY ALONG WITH UNCOMFORTABLY HUMID CONDITIONS AS SFC
DWPTS RISE WELL INTO THE 60S...TO AROUND 70F LOCALLY. MIXING TO
AROUND 850MB OR SO ON FCST SOUNDINGS YIELDS MAX TEMPS GENERALLY IN
THE MID TO UPPER 80S. IT WILL BE LOCALLY WARMER WHERE SOUTHERLY
WINDS DOWNSLOPE...AND ONCE AGAIN...IT WILL BE COOLER NEAR LAKE
MICHIGAN...ESPECIALLY E OF KESC.

TONIGHT...ATTENTION TURNS TO SVR STORMS DEVELOPING IN ND THAT WILL
GROW UPSCALE INTO AN MCS IN RESPONSE TO SHORTWAVE MOVING OUT OF THE
ROCKIES AND ACROSS THE NRN PLAINS TOWARD THE UPPER LAKES. MODELS ARE
IN GOOD AGREEMENT ON DEVELOPING CONVECTION OVER ND THIS AFTN.
HOWEVER...AS TIME PROGRESSES...MODELS DIVERGE ON THE EVOLUTION OF
STORMS AND LIKELY MCS TONIGHT INTO TUE MORNING. GIVEN TRACK OF
SHORTWAVE AND POOL OF ELAVATED INSTABILITY ACROSS MN/WI AVBL FOR
STORMS TO TAKE ADVANTAGE OF OVERNIGHT...BELIEVE THE NCEP ARW/NMM AND
NSSL WRF OFFER THE MOST VIABLE SOLUTIONS OF WHAT WILL TRANSPIRE.
THOSE MODELS SHOW TSTMS SPREADING INTO FAR WRN UPPER MI AFT 06Z AND
REACHING CNTRL UPPER MI BY 12Z. WHILE OVERNIGHT TIMING SUGGESTS
STORMS WILL BE WEAKENING AS THEY ARRIVE...DEGREE OF INSTABILITY AVBL
FOR INFLOW MAY STILL SUPPORT SOME SVR THREAT AT LEAST INTO FAR WRN
UPPER MI.

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 748 AM EDT MON JUL 21 2014

MAIN FOCUS IS ON TUESDAY AS MCS ACTIVITY SHOULD BE MOVING ACROSS THE
CWA. DEVELOPMENT OF A FORWARD PROPAGATING MCS OVER ND MON EVENING
LOOKS LIKELY TO OCCUR...WHICH WOULD BRING THE REMNANTS OF THE MCS
INTO THE CWA MON NIGHT /SEE SHORT TERM DISCUSSION/. THE REMNANTS OF
THE MCS SHOULD THEN MOVE ACROSS THE CWA DURING THE DAY TUE...WITH
THE CURRENT FAVORED TRACK OF THE BEST PRECIP CHANCES OVER LAKE
SUPERIOR/NRN UPPER MI. SO MUCH OF THE PRECIP AND STORM INTENSITY
DURING THE DAY TUE WILL BE DEPENDENT ON MANY OTHER FACTORS...SO
CONFIDENCE IN EXACT DETAILS IS LIMITED. HOWEVER...THINK THAT THE
THREAT FOR SEVERE WEATHER IS LOW GIVEN THAT MORNING INSTABILITY
SHOULD BE AROUND 1000J/KG /HIGHEST OVER THE W NEAR IWD/. AS THE
CONVECTION MOVES E INTO THE AFTERNOON IT WILL ENCOUNTER MORE STABLE
CONDITIONS...SO SEVERE WEATHER IS EVEN LESS LIKELY. A WAKE LOW IS
QUITE POSSIBLE BEHIND THE CONVECTION...WHICH WOULD LEAD TO GUSTY
WINDS...ESPECIALLY OVER LAKE SUPERIOR. WOULD THINK THAT THE THREAT
FOR SIGNIFICANT SEICHE ACTIVITY ON LAKE SUPERIOR IS PRETTY HIGH. MAY
SEE ANOTHER WAVE OF CONVECTION TRYING TO MOVE THROUGH BEHIND THE
INITIAL CONVECTION...BUT THINK THAT THERE WILL NOT BE AS MUCH
INSTABILITY TO WORK WITH DUE TO THE EARLIER CONVECTION.

PRECIP SHOULD BE SE OF THE CWA BY 06Z WED...AND DRY AND COOLER
WEATHER IS EXPECTED THROUGH FRI AS A SFC HIGH MOVES THROUGH THE
REGION. PRECIP CHANCES WILL RETURN OVER THE WEEKEND AS A MORE
UNSETTLED PATTERN SETTLES OVER THE REGION.
&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 748 AM EDT MON JUL 21 2014

VFR CONDITIONS WILL PREVAIL AT KIWD/KCMX/KSAW INTO THE EVENING HRS.
SHRA/TSTMS DEVELOPING OVER THE NRN PLAINS THIS AFTN/EVENING WILL
MOVE E. THE STORMS SHOULD HOLD TOGETHER AND REACH WRN UPPER MI LATE
TONIGHT...AFFECTING KIWD/KCMX AROUND 09Z OR LATER. MVFR CONDITIONS
SHOULD ACCOMPANY THE PCPN WITH POTENTIAL FOR IFR.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 535 AM EDT MON JUL 21 2014

SOUTHERLY WINDS WILL CONTINUE OVER MOST OF LAKE SUPERIOR
TODAY/TONIGHT. WHILE S WINDS WILL BE MOSTLY UNDER 20KT...STRONGER
WINDS/GUSTS INTO THE 20-30KT RANGE WILL LIKELY OCCUR AT THE HIGHER
OBS PLATFORMS...MAINLY THIS MORNING AND MAINLY OVER THE E HALF OF
LAKE SUPERIOR. ON TUE...A LOW PRES SYSTEM WILL PASS ACROSS THE UPPER
LAKES...BRINGING A WIND SHIFT TO THE N. AGAIN...THE STRONGER WINDS
OF 15-25KT WILL LIKELY OCCUR OVER ERN LAKE SUPERIOR. IN ADDITION...
DEPENDING ON STRENGTH/COVERAGE AND EVOLUTION OF TSTMS MOVING ACROSS
LAKE SUPERIOR TONIGHT/TUE AHEAD OF LOW...THERE MAY BE A PERIOD OF
STRONG WINDS ACROSS MUCH OF THE LAKE FOR A TIME LATE TONIGHT AND
TUE. HIGH PRES WILL SETTLE INTO THE GREAT LAKES LATE WED THRU
FRI...PROVIDING A PERIOD OF LIGHT WINDS.

ON A FINAL NOTE...FOG MAY EXPAND ACROSS LAKE SUPERIOR TODAY THRU
TUE...ESPECIALLY ONCE PCPN OCCURS.
&&

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

$$

SHORT TERM...ROLFSON
LONG TERM...TITUS
AVIATION...ROLFSON
MARINE...ROLFSON






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