000
FXUS63 KMQT 202353
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
753 PM EDT MON MAY 20 2013

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 409 PM EDT MON MAY 20 2013

12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW CLOSED UPR LO OVER
THE NRN PLAINS UPSTREAM OF UPR RDG EXTENDING FM THE CENTRAL GRT LKS
INTO THE SE CONUS. DRY SLOTTING ALF TO THE E OF THIS FEATURE AS
SHOWN BY HIER 12Z H85 AND H7 DEWPT DEPRESSIONS AT GRB/DAVENPORT IA
HAS TENDED TO STUNT SHRA DVLPMENT OVER THE W HALF OF THE CWA...BUT
MORE PERSISTENT AXIS OF GREATER MSTR/HIER KINX OVER THE ERN CWA AND
SHRTWV MOVING NE FM WI HAS LED TO MORE SHRA/ELEVATED TS IN THAT
AREA. LO CLDS HAVE LINGERED N OF SFC WARM FNT AS WELL EXCEPT OVER
THE W...WHERE SOME LLVL DRYING/DAYTIME HEATING HAVE TENDED TO MIX
OUT THE LO CLDS AND BOOST TEMPS INTO THE 70S. TO THE W...12Z MPX
RAOB SHOWS A MUCH MOISTER AIRMASS. SOME SHRA ARE DVLPG IN WRN WI
WITH DAYTIME HEATING/DESTABILIZATION ON THE ERN EDGE OF THIS DEEPER
MSTR. FARTHER TO THE SW...ANOTHER SHRTWV IS ROTATING ARND THE CLOSED
LO AND THRU THE SCENTRAL PLAINS.

CHALLENGING FCST THRU THE SHORT TERM. BUT WITH CUTOFF LO SWIRLING TO
THE W...TENDED TO FOLLOW THE LEAST PROGRESSIVE MODELS FOR FCST
PREPARATION.

TNGT...EXPECT UPR DRY SLOT TO BRING A RELATIVELY QUIET LATE AFTN/
EARLY EVNG TIME TO THE CWA PER MOST OF RECENT HI RES GUIDANCE.
EXPECT LINGERING SHRA/TS OVER THE E TO END LATE THIS AFTN WITH
DRYING AT H85-7 SLOWLY PUSHING AXIS OF HIER MSTR TO THE E. SHRA NOW
DVLPG IN WRN WI E OF MOISTER AIRMASS SHOWN ON THE 12Z MPX RAOB AND
NEAR THE WRN EDGE OF THE DRY SLOT MAY IMPACT THE WRN ZNS THIS EVNG
AS THEY DRIFT NWD IN THE SLY FLOW ALF E OF THE UPR LO...SO CARRIED
CHC POPS IN THIS AREA THRU THE EVNG. LATER TNGT...PREFERRED 12Z
GFS/REG CNDN MODELS SHOW MORE SHRA/TS ARRIVING OVER THE SCENTRAL
COUNTIES AS SHRTWV NOW MOVING THRU THE SCENTRAL PLAINS ACCOMPANIED
BY JET MAX/UPR DVGC CORE ROTATES NEWD AHEAD OF THE NEARLY STNRY
CLOSED LO TO THE W. FCST LIKELY POPS ARRIVING LATE IN THIS AREA.
OTRW..TENDED TOWARD THE HIER END OF GUIDANCE FOR MIN TEMPS EXCEPT
NEAR THE GREAT LKS.

TUE...SHRA/SOME TS ASSOCIATED WITH DISTURBANCE LIFTING NEWD E OF THE
MAIN CLOSED LO WL IMPACT MAINLY THE CENTRAL/ERN ZNS IN THE MRNG
BEFORE GIVING WAY TO MID LVL DRYING. APRCH OF ANOTHER DISTURBANCE FM
THE SSW ROTATING ARND THE CLOSED LO MAY BRING ANOTHER BATCH OF
SHRA/TS NEAR THE WI BORDER LATER IN THE DAY. HI TEMPS FCST WL BE
TRICKY. THE CNDN MODEL HINTS AT MORE OF A SFC WAVE RIDING THRU THE
ECENTRAL AND HINTS THERE COULD BE MORE SUNSHINE IN THIS AREA IN THE
AFTN. RIGHT NOW...PLAYED THE FCST FOR MORE CLDS/A LLVL NE FLOW OFF
THE COOL WATERS OF LK SUP TO THE N OF STNRY FNT JUST TO THE W.

.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 409 PM EDT MON MAY 20 2013

THE FOCUS OF THE LONG TERM FORECAST THIS WEEK WILL BE THE PASSING OF
A LOW PRESSURE SYSTEM ACROSS THE GREAT LAKES REGION. CLOSED 500MB
LOW OVER THE NORTHERN PLAINS THIS AFTERNOON WILL MAKE ITS WAY JUST
SOUTH OF UPPER MICHIGAN ON WEDNESDAY...GRADUALLY FILLING AS IT
REACHES THE EASTERN SEABOARD BY FRIDAY AFTERNOON. THIS LOW EXTENDS
FROM A TROUGH ASSOCIATED WITH STRONGER LOW PRESSURE SITUATED OVER
NORTHERN QUEBEC. AT THE 300MB LEVEL LEFT EXIT REGION DIVERGENCE HAS
HELPED WITH THE DEVELOPMENT OF THE LOW PRESSURE SYSTEM OVER THE
PLAINS. THIS JET WILL SHIFT NORTHWARD AND BY WEDNESDAY UPPER
MICHIGAN WILL BE SLIGHTLY NORTH OF THE BEST UPPER LEVEL SUPPORT...IN
THE RIGHT ENTRANCE REGION. 850-500MB QVECTOR CONVERGENCE SHOWS BEST
LIFT GENERALLY ALONG SOUTHWESTERN-SOUTHERN UPPER MI/LOWER
MI/WISCONSIN ACCORDINGLY. MEANWHILE...A WEAK SURFACE LOW DEVELOPING
IN THE PLAINS MOVES NORTHWARD ALONG THE TROUGH...PASSING THROUGH
LOWER MI AND THE LOWER GREAT LAKES WEDNESDAY AFTERNOON INTO
WEDNESDAY NIGHT. MODEL SOUNDINGS SHOW ABUNDANT MOISTURE REMAINS
THROUGH ALL OF WEDNESDAY FOR CENTRAL/EASTERN UPPER MI BEFORE THE
VERY DRY AIRMASS/HIGH PRESSURE ARRIVES WEDNESDAY NIGHT/THURSDAY.
PWATS DURING THIS TIME STILL REMAIN AS HIGH AS 150 PERCENT OF
NORMAL. HAVE A DIMINISHING TREND FOR POPS FROM WEDNESDAY AFTERNOON
ONWARD AS DRY AIR INFILTRATES THE AREA AND THE SFC LOW EXITS THE
REGION. ADDITIONALLY...WITH ABUNDANT MOISTURE IN PLACE EXPECTING FOG
ACROSS LAKE SUPERIOR AND LAKE MICHIGAN FOR TUESDAY NIGHT/EARLY
WEDNESDAY AFTERNOON. ONCE THE DRIER AIR MOVES IN THE FOG WILL
DISSIPATE.

UPPER LEVEL HIGH OVER THE CANADIAN PRAIRIE WILL SINK SOUTHWARD AND
MERGE WITH THE BUILDING RIDGE OVER THE CENTRAL UNITED STATES ON
THURSDAY MORNING...BRINGING AN END TO PRECIPITATION FOR UPPER MI.
WITH DRY AIR SCOURING OUT THE CLOUDS...NORTHERLY WINDS...AND 850MB
TEMPS AROUND 2-4C...THURSDAY AFTERNOON LOOKS TO BE MOSTLY SUNNY WITH
TEMPS IN THE MID-UPPER 50S AND MAYBE EVEN LOW 60S....BELOW NORMAL BY
LATE MAY STANDARDS. MIXED LAYER DEWPOINTS BRING DEWPOINTS INTO THE
UPPER 20S/30S WHICH BRINGS MINIMUM RH FIELDS TO 30-40 PERCENT FOR
MID AFTERNOON ON THURSDAY.

A SHORTWAVE ROTATING AROUND THE 500MB LOW IN QUEBEC WILL PASS
OVERHEAD FRIDAY AFTERNOON BUT WITH DRY AIR FIRMLY IN PLACE NOTHING
WILL COME OF IT BEYOND SOME SCATTERED CLOUDS. AFTER FRIDAY THE UPPER
LEVEL RIDGE WILL SPRAWL ACROSS MUCH OF THE CENTRAL AND EASTERN
UNITED STATES. THIS WILL KEEP A DRIER AIRMASS IN PLACE AND KEEP
CONDITIONS QUIET THROUGH SATURDAY AFTERNOON. A LOW PRESSURE
TROUGH/SHORTWAVE WILL MOVE INTO THE GREAT LAKES AREA SATURDAY
EVENING INTO MONDAY...BRINGING A CHANCE FOR RAIN SHOWERS INTO THE
CWA.
&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 753 PM EDT MON MAY 20 2013

AVIATION FCST WILL CONTINUE TO BE CHALLENING THRU THIS PERIOD. WITH
EASTERLY UPSLOPE WINDS DOMINATING AT KCMX THRU THE NIGHT...VLIFR
CONDITIONS WILL LIKELY CONTINUE TO PREVAIL. MAY SEE SOME IMPROVEMENT
TUE MORNING AND MAYBE MORE SO TUE AFTN AS LOW-LEVEL WINDS BACK A
LITTLE MORE TO THE NE AND DIMINISH THE UPSLOPING. EXPECT SOME SHRA
AT TIMES...ESPECIALLY THIS EVENING AND THEN TUE MORNING. AT KIWD...
SHRA OVER THE NEXT FEW HRS WILL RESULT IN OCNL MVFR CONDITIONS.
OTHERWISE...VFR CONDITIONS SHOULD FALL TO MVFR THAN IFR OVERNIGHT AS
WINDS SHIFT TO THE NE...BRINGING COOL/MOIST AIR OFF LAKE SUPERIOR.
MAY SEE IMPROVEMENT TO LOW MVFR TUE AFTN. AT KSAW...STRATUS PATCHES
LURKING TO THE E AND SE SHOULD SPREAD/EXPAND NW THIS EVENING AS
DAYTIME HEATING COMES TO AN END. EXPECT CONDITIONS TO FALL TO MVFR
THEN IFR BY MID/LATE EVENING. PERIOD OF SHRA/LIFR CONDITIONS WILL
OCCUR LATE TONIGHT/TUE MORNING AS DISTURBANCE LIFTS NE INTO THE
UPPER LAKES. WITH NE WINDS DURING THE DAY TUE...MAY NOT SEE
CONDITIONS IMPROVE ABOVE IFR AT KSAW.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 409 PM EDT MON MAY 20 2013

NE GALES OVER FAR WESTERN LAKE SUP WITH FAVORABLE TERRAIN FUNNELING
OF THAT FLOW WILL TEND TO DIMINISH TO 20 TO 25 KT THIS EVENING WITH
WEAKENING PRES GRADIENT. WILL LET GALE WARNING EXPIRE AT 03Z.
OTHERWISE...EXPECT PATCHY FOG TO SLOWLY DISSIPATE FROM THE N BY
LATER TUE WITH GRADUAL ARRIVAL OF DRIER AIR IN PERSISTENT NE FLOW TO
THE S OF HI PRES OVER ONTARIO.

A LOW PRESSURE SYSTEM WILL PASS JUST SOUTH OF LAKE SUPERIOR
WEDNESDAY. WINDS WILL BECOME MORE NORTHERLY AS THE LOW MOVES EASTWARD
ON THURSDAY BUT ARE EXPECTED TO REMAIN LESS THAN 25 KNOTS. HIGH
PRESSURE WILL FILTER IN BEHIND THE LOW THURSDAY EVENING AND REMAIN
THROUGH THE WEEKEND...KEEPING WINDS GENERALLY LESS THAN 20 KNOTS.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
  DENSE FOG ADVISORY UNTIL NOON EDT TUESDAY FOR LSZ243>249-263>267.

  DENSE FOG ADVISORY FROM 11 PM EDT /10 PM CDT/ THIS EVENING TO
     NOON EDT /11 AM CDT/ TUESDAY FOR LSZ162.

  GALE WARNING UNTIL 11 PM EDT /10 PM CDT/ THIS EVENING FOR LSZ162.

LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...KC
LONG TERM...MCD
AVIATION...ROLFSON
MARINE...MCD