663 
FXUS63 KMQT 250034 AAA
AFDMQT

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE MARQUETTE MI
834 PM EDT TUE SEP 24 2013

.UPDATE...
ISSUED AT 833 PM EDT TUE SEP 24 2013

QUIET NIGHT UNDERWAY AS HIGH PRESSURE IS OVERHEAD. NO BIG CHANGES TO 
GOING FORECAST. MAIN ISSUE OVERNIGHT TONIGHT THROUGH AROUND DAYBREAK 
WEDNESDAY IS EXTENT OF DENSE FOG. DWPNTS STAYED MAINLY IN THE UPR 
40S TO AROUND 50 DEGREES THIS AFTN AND WITH WINDS BECOMING LIGHT 
TONIGHT...EXPECT TEMPS TO FALL WELL BELOW THE CROSSOVER TEMPS INTO
THE LOWER 40S OR MAYBE EVEN UPPER 30S LATE TONIGHT. FROST RISK WILL
BE MINIMAL...CONFINED TO INTERIOR EAST CWA...SINCE THE DWPNTS ARE 
WELL ABOVE FREEZING. FOG SHOULD BE PRETTY WIDESPREAD...BUT NOT SURE
ON THE COVERAGE OF DENSE FOG. TWEAKED GRIDS TO ADD SOME DENSE FOG
WORDING AND WILL RE-ISSUE THE SPECIAL WEATHER STATEMENT. GREATEST
CHANCE OF SEEING VSBY LESS THAN ONE-QUARTER MILE WOULD BE ACROSS IRON
AND DICKINSON COUNTIES AND ALSO AFFECTING AREAS FROM SOUTHERN BARAGA
COUNTY INTO WESTERN MARQUETTE COUNTY. IF THE DENSE FOG ENDS UP MORE
WIDESPREAD THAN EXPECTED...MID SHIFT MAY NEED TO PUT OUT A SHORT
DURATION DENSE FOG ADVY FOR THE MORNING COMMUTE TO WORK AND SCHOOL.
&&

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 336 PM EDT TUE SEP 24 2013

MILD AND DRY CONDITIONS WILL PERSIST THROUGH WEDNESDAY. THE MAIN 
FOCUS OF THE PERIOD WILL BE THE POTENTIAL FOR WIDESPREAD FOG 
DEVELOPMENT TONIGHT...MAINLY ACROSS THE INTERIOR CENTRAL AND EAST.

TONIGHT...UPPER MI REMAINS UNDER THE INFLUENCE OF THE WESTERN EDGE 
OF A SHARP MID-LEVEL RIDGE...WHICH IS SITUATED BETWEEN A DECAYING 
TROUGH MOVING INTO THE UPPER AND MID MS VALLEY...AND A SLIGHTLY 
RETROGRADING CLOSED LOW NEAR MAINE. MEANWHILE...NEARLY STATIONARY 
HIGH PRESSURE IS OVER FAR EASTERN ONTARIO.

MINIMAL PATTERN CHANGES OVER THE NEXT DAY SHOULD RESULT IN A 
GENERALLY PERSISTENT FORECAST FROM THE WEATHER TODAY. THE MID-LEVEL 
TROUGH NEARING THE MS VALLEY IS EXPECTED TO GRADUALLY WEAKEN...WITH 
A BROAD AND WEAK CUT-OFF LOW FORMING ALONG THE SOUTHERN EXTENT 
ACROSS THE LOWER OHIO VALLEY. THE REST OF THE TROUGH WILL QUICKLY 
LIFT NE AND POSSIBLY BRUSH THE WESTERN CWA WITH SOME DECAYING CIRRUS 
THROUGH WEDNESDAY.

FOG DEVELOPMENT TONIGHT CONTINUES TO BE THE MAIN FORECAST CHALLENGE 
ATTM. WHILE THE MID-LEVEL RIDGE SLOWLY TRACKS EAST...SFC WINDS WILL 
WEAKEN AND BECOME NEARLY CALM AS THE SFC HIGH BUILDS WESTWARD TO 
OVER THE EASTERN CWA BY WEDNESDAY MORNING. DRY AIR ABOVE A LOW-LEVEL 
INVERSION WILL BE PRESENT AS INDICATED BY PWAT VALUES OF 0.4-0.5 
INCHES ON FORECAST SOUNDINGS. LIGHT SE WINDS OFF LAKE MI SHOULD 
ASSIST WITH SOME INITIAL UPSLOPE/MOISTENING ACROSS THE CENTRAL CWA 
THIS EVENING. A PERSISTENT STRATOCUMULUS DECK ALONG GREEN BAY AND 
LAKE MI TODAY IS INDICATIVE OF THE LOW-LEVEL MOISTURE ALREADY 
AVAILABLE. EVEN MORE SO...CROSS-OVER TEMPS WILL ONLY BE AS LOW AS 
THE UPPER 40S. WITH LOWS EXPECTED TO GRADUALLY DROP TO THE LOW 40S 
OVERNIGHT...FOG SHOULD BEGIN DEVELOPING BY 06Z AND BECOME MOST 
WIDESPREAD AROUND SUNRISE. THE BEST CHANCE TO SEE WIDESPREAD 
FOG...POSSIBLY DENSE AT TIMES...WILL BE ALONG THE WI BORDER FROM 
IRON RIVER TO MENOMINEE NORTH TO A LINE FROM MICHIGAMME TO ESCANABA. 
HAVE ISSUED A SPECIAL WX STATEMENT HIGHLIGHTING THE CENTRAL CWA.

WITH A QUICKLY LOWERING SUN ANGLE...FOG AND STRATUS WERE SLOW TO 
ERODE THIS MORNING. A SIMILAR TREND CAN BE EXPECTED WEDNESDAY...SO 
ANY FOG WILL LIKELY SLOWLY LIFT TO A STRATOCUMULUS LAYER BEFORE 
GRADUALLY DISSIPATING BY THE AFTERNOON. WITH A STOUT INVERSION 
AROUND 3KFT AND CONTINUING MOISTURE FLOWING OFF LAKE MI AND GREEN 
BAY...EXCEPT A FLAT STRATOCU DECK TO REMAIN ACROSS THE SOUTH-CENTRAL 
AND EASTERN CWA FOR MUCH OF THE DAY. LOWERED TEMPS A TOUCH GIVEN 
COOLER TRENDS TODAY WITH SIMILAR CONDITIONS.

.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 424 PM EDT TUE SEP 24 2013

HIGH PRESSURE WILL DOMINATE MUCH OF THIS TIME PERIOD. AT 00Z 
THURSDAY THE UPPER GREAT LAKES WILL BE DOMINATED BY HIGH PRESSURE AT 
THE SFC AND ALOFT...WITH LOW PRESSURE OVER THE INTERMOUNTAIN WEST UP 
THROUGH W CANADA. THE RESULT FOR OUR REGION WILL BE CONTINUED DRY 
WEATHER AND LIGHT WINDS.

WINDS AND TEMPS WILL BE ON THE INCREASE THURSDAY AFTERNOON AS THE 
PRESSURE GRADIENT INCREASES BETWEEN THE HIGH INCREASING OVER THE E 
PORTION OF THE CWA...AND THE LINGERING TROUGH TO THE W. WHILE THERE 
ARE STILL SOME SIGNIFICANT DIFFERENCES IN THE MID RANGE 
MODELS...THEY HAVE BECOME A LOT MORE PROGRESSIVE THAN THE CLOSED LOW 
DEPICTED OFF THE ECMWF OF 24HRS AGO. NOW THE 12Z MODELS HAVE THE 
500MB TROUGH SET UP ACROSS MN AT 00Z SUNDAY...WITH THE COLD FRONT 
EITHER ACROSS THE CENTRAL PORTIONS OF THE CWA AT OR OVER THE FAR W. 
THE OVERALL TREND IS THE SAME...WITH THE ECMWF BEING THE SLOWER 
SOLUTION. EXPECT THE FRONT TO BE KICKED E BY 15Z SUNDAY. KEPT THE 
AREA TS FREE...WITH ONLY A THIN-MODERATE LINE OF SHOWERS EXPECTED. 
THE ECMWF DOES HAVE MU CAPE VALUES NEARING 100J/KG ALONG THE WI 
BORDER SATURDAY...WITH IS PRETTY MINOR. WILL CONTINUE TO FINE-TUNE 
THIS PORTION OF THE FCST AS THE TIME NEARS.

HIGH PRESSURE SHOULD QUICKLY FILL BACK IN BEHIND THE COLD FRONT 
SUNDAY AFTERNOON. WENT AHEAD AND DIMINISHED THE POTENTIAL FOR 
LINGERING SHOWERS A BIT MORE SUNDAY AFTERNOON-SUNDAY NIGHT...AS WELL 
AS MONDAY AND MONDAY NIGHT WITH NO MORE CLOSED LOW ANTICIPATED. 
THERE IS STILL QUITE A DIFFERENCE IN THE 500MB PATTERN FOR THE START 
OF NEXT WEEK.
&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 712 PM EDT TUE SEP 24 2013

VFR CONDITIONS THIS EVENING AT ALL SITES AS HIGH PRESSURE REMAINS IN 
CONTROL. MAIN CONCERN WILL BE FOG DEVELOPMENT AT SAW AND CMX LATE 
TONIGHT. EXPECT IWD TO REMAIN VFR WITH LIGHT DOWNSLOPING S WINDS.

PERSISTENT CONDITIONS AND CALM WINDS UNDER HIGH PRESSURE WILL LEAD 
TO RADIATIONAL FOG DEVELOPMENT ACROSS CENTRAL UPPER MI OVERNIGHT. 
KEPT SAW FORECAST REACHING LIFR-VLIFR THRESHOLD LATE TONIGHT INTO 
WEDNESDAY MORNING. STILL SOME POTENTIAL THAT VLIFR/LANDING MIN 
CONDITIONS COULD BE OBSERVED AS EARLY AS 08Z AND AS LATE AS 13Z. 
AS FOR CMX...EXPECT SOME GROUND FOG WITH MAINLY MVFR CONDITIONS AS
WAS SEEN ON TUESDAY MORNING. MAY SEE BRIEF IFR VSBY AS WELL.

EXPECT FOG/LOW STRATUS TO DISSIPATE SLOWLY ON WEDNESDAY AT SAW WITH 
MIXING NOT KICKING IN UNTIL AFTN. RETAINED SLOWER DISSIPATING 
TREND...WITH SAW POSSIBLY NOT BREAKING OUT UNTIL MID AFTN.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 336 PM EDT TUE SEP 24 2013

HIGH PRESSURE WILL KEEP WINDS UNDER 15 KNOTS FROM THE SOUTH TO 
SOUTHEAST THROUGH THURSDAY BEFORE AN APPROACHING TROUGH BEGINS TO 
VEER WINDS FROM THE SOUTH BY FRIDAY. SOUTH WINDS WILL GRADUALLY 
INCREASE TO UP TO 20 KNOTS THROUGH SATURDAY AS LOW PRESSURE TRACKING 
ACROSS NORTHERN MANITOBA PASSES A COLD FRONT ACROSS LAKE SUPERIOR 
SATURDAY EVENING. WESTERLY WINDS UNDER 15 KNOTS WILL ENSUE THROUGH 
EARLY NEXT WEEK AS HIGH PRESSURE BUILDS BACK INTO THE REGION.
&&

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

$$

UPDATE...JLA
SHORT TERM...KLUBER
LONG TERM...KF
AVIATION...JLA
MARINE...KLUBER