FXUS63 KMQT 260533 AAB
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
1232 AM EST THU NOV 26 2009

.SHORT TERM /TONIGHT AND THURSDAY/... ISSUED AT 340 PM EST

LOOKING AT THE LATEST WATER VAPOR IMAGERY...PLENTY OF MOISTURE 
REMAINED ACROSS THE UPPER GREAT LAKES...AS ONE SHORTWAVE SWINGING 
ACROSS MICHIGAN...WITH ANOTHER DIVING SSE THROUGH FAR SOUTHERN 
MINNESOTA AND NORTHERN IOWA. AT THE SURFACE...HIGH PRESSURE IS 
SITUATED ACROSS THE NORTHERN AND CENTRAL PLAINS. THE NEAREST AND 
MOST INFLUENTIAL SURFACE LOW IS OVER NORTHERN LAKE MICHIGAN.

AS FOR THE FORECAST...EXPECT THE SURFACE LOW CURRENTLY SET UP ACROSS 
NORTHERN LAKE MICHIGAN TO MOVE INTO NORTHERN LAKE HURON BY THURSDAY 
AFTERNOON THROUGH EARLY THURSDAY EVENING. HIGH PRESSURE MOVING IN 
FROM THE CENTRAL AND NORTHERN PLAINS WILL MAKE IT AS FAR EAST AS 
MINNESOTA AND FAR WESTERN LAKE SUPERIOR. OTHERWISE ACROSS LAKE 
SUPERIOR AND FAR NORTHERN UPPER MICHIGAN...A WEAK TROUGH WILL LINGER 
BEHIND THE SURFACE LOW THROUGH THE END OF THE PERIOD. AT 500MB...THE 
SHORTWAVE TROUGH ACROSS MINNESOTA WILL BECOME THE DOMINATE FEATURE 
THROUGH EARLY THURSDAY MORNING AS IT DIVES ACROSS ILLINOIS AND 
INDIANA BY DAYBREAK THURSDAY. MUCH OF THE ENERGY WILL REMAIN WELL TO 
OUR SOUTH THIS EVENING. 

HOWEVER...AS WE NEAR DAYBREAK THURSDAY...AN ADDITIONAL WAVE WILL 
SINK SOUTHWARD FROM ONTARIO...AND INTO WESTERN UPPER MICHIGAN/LAKE 
SUPERIOR. EXPECT THIS KICKER TO MOVE ACROSS EASTERN UPPER 
MICHIGAN/LAKE SUPERIOR BY 00Z FRIDAY. AS A RESULT...A QUICK DECREASE 
IN CLOUD COVER IS NOT ANTICIPATED OVERNIGHT AS THE SURFACE LOW 
EXITS. NORTHWESTERLY FLOW ACROSS LAKE SUPERIOR WILL AID IN KEEPING A 
CLOUDY TO MOSTLY CLOUDY SKY ACROSS THE KEWEENAW PENINSULA...AND EAST 
OF MARQUETTE THROUGH THE DAY THURSDAY.

WILL RUN WITH A NON-DIURNAL TEMPERATURE OVERNIGHT...AND MORE 
IMPORTANTLY DURING THE DAYLIGHT HOURS THURSDAY...AS COLD AIR SURGES 
IN AFTER 06Z THIS EVENING. 850MB TEMPERATURES ARE EXPECTED TO FALL 
FROM CURRENT READINGS OF -3 TO 0C...TO -11C TO -6C BY 00Z FRIDAY 
/TEMPS FROM WEST TO EAST CWA/. THE MAIN CONCERN WITH THIS FORECAST 
PACKAGE REMAINS THE POTENTIAL FOR SNOW LATE TONIGHT THROUGH 
THURSDAY. COLD AIR WILL SLOWLY ARRIVE...WITH THE COLDEST AIR 
ARRIVING AFTER THE DEPARTURE OF THE BEST LOW LEVEL MOISTURE FOR LES. 
AS A RESULT...ONLY SMALL CHANGES WILL BE NEEDED TO OUR ONGOING 
FORECAST. NAM LOOKS TO BE THE STRONGEST OF THE AVAILABLE MODEL 
GUIDANCE...AND WILL NOT BE UTILIZED AS MUCH AS THE GFS AND SMALLER 
SCALE MODELS FOR THIS PERIOD.

.LONG TERM /THU NIGHT THRU WED/...

850MB THERMAL TROF OF -8 TO -10C WILL BE SHIFTING ACROSS LAKE 
SUPERIOR THU NIGHT...PROVIDING SUFFICIENT INSTABILITY FOR LES. 
HOWEVER...NAM/GFS FCST SOUNDINGS OVER ALL BUT THE FAR ERN PART OF 
THE LAKE SUGGEST LES WILL STRUGGLE AS BOTH SHOW INVERSION OF 4-5KFT 
WITH A WELL-MIXED BOUNDARY LAYER LOOK. THUS...KEPT POPS ONLY IN THE 
LOW CHC/SLIGHT CHC CATEGORY OVER THE W AND THAT MAY BE TOO HIGH. 
OVER THE E...DEEP MOISTURE IS STILL PRESENT. WITH LONGER FETCH AND 
PRECONDITIONING FROM LAKE NIPIGON...HIGH CHC TO LIKELY POPS APPEAR 
WARRANTED. EXPECT ANY SNOW ACCUMULATIONS TO BE LESS THAN 1 INCH. AS 
FOR TEMPS...NOT OUT OF THE QUESTION THAT SOME LOCATIONS OVER THE SW 
FCST AREA MAY SEE CLOUDS BREAK ENOUGH TO GET QUITE COLD AS WINDS 
DIMINISH. NAM MOS HAS MINS DOWN INTO THE MID TEENS OVER MUCH OF THE 
W HALF. NUDGED MINS DOWN A BIT...BUT RIGHT NOW EXPECT ENOUGH CLOUD 
COVER TO KEEP TEMPS FROM FALLING AS LOW AS NAM MOS SUGGESTS.  

LINGERING SCT LES OVER THE ERN FCST AREA WILL WIND DOWN/POSSIBLY END 
FRI AS 850MB TROF SHIFTS E AND SFC HIGH PRES RIDGE ARRIVES OVER 
UPPER MI. QUIET/DRY WEATHER WILL THEN BE THE RULE FRI NIGHT/SAT AS 
SFC HIGH PRES RIDGE SLOWLY DRIFTS E. ALTHOUGH WAA WILL BE 
UNDERWAY...THETA SFCS SHOW FAIRLY LIGHT FLOW AND WIND IS DIRECTED AT 
A SMALL ANGLE TO ISOBARS...RESULTING IN WEAK ISENTROPIC UPGLIDE. MAY 
SEE A FAIR AMOUNT OF MID/HIGH CLOUDS...BUT NO PCPN FRI NIGHT/SAT.   

SUN THRU WED...MEDIUM RANGE MODELS HAVE BEEN STRUGGLING WITH THE 
DETAILS FOR THE FIRST HALF OF NEXT WEEK...BUT TODAYS MODEL RUNS 
(MORE NOTABLY THE 12Z RUNS) ARE TRENDING TOWARD BETTER AGREEMENT. IF 
ANYTHING...THE ECMWF HAS SHOWN A BIT MORE RUN-TO-RUN CONTINUITY. 
EARLY IN THE WEEK...THE ECMWF IS A LITTLE MORE PROGRESSIVE WITH THE 
NRN PORTION OF A TROF SHIFTING ACROSS THE CONUS WHILE SRN PORTION 
LAGS BACK IN THE SRN PLAINS TO SRN ROCKIES. THE 00Z/06Z GFS THEN 
TAKE THE ENERGY IN THE SRN PORTION OF THE TROF AND LIFT IT INTO THE 
GREAT LAKES MIDWEEK AS MORE ENERGY DIVES INTO THE THE CNTRL CONUS. 
RESULT IS A RAIN/POSSIBLE SNOW STORM FOR PORTIONS OF THE WRN GREAT 
LAKES REGION MIDWEEK. 00Z GFS ENSEMBLES SHOW LITTLE SUPPORT FOR SUCH 
A SOLUTION. THE GLOBAL GEM SHOWS SOME POTENTIAL FOR A GFS TYPE 
SOLUTION...ONLY IT IS MUCH FARTHER E TOWARD THE E COAST WITH THE LOW 
PRES. SO...FCST TODAY WILL LEAN TOWARD THE ECMWF SOLUTION. LOW PRES 
TRACKING THRU THE UPPER GREAT LAKES EARLY SUN ASSOCIATED WITH NRN 
PORTION OF AFOREMENTIONED TROF WILL BRING POTENTIAL OF A LITTLE 
-RA/-SN SUN. IN ITS WAKE...AIRMASS WILL BE COLD ENOUGH (AROUND -9C 
AT 850MB) FOR LES SUN NIGHT/MON MORNING FOR AREAS FAVORED BY NW 
FLOW. MAY SEE SOME LIGHT ACCUMULATIONS. LES WILL WIND DOWN/END 
MON/MON NIGHT AS WAA GETS UNDERWAY AND WINDS BACK SW WITH SFC HIGH 
PRES RIDGE PASSAGE. ALTHOUGH CONFIDENCE IS VERY LOW FOR THE MIDDLE 
OF NEXT WEEK GIVEN SPREAD OF SOLUTIONS AND LACK OF MODEL 
CONTINUITY...WILL INCLUDE MINOR CHC OF RAIN/SNOW WED AS NEXT 
SHORTWAVE APPROACHES. OVERALL...TEMPS SUN THRU WED WILL GENERALLY BE 
NEAR OR A LITTLE ABOVE NORMAL. COLDEST DAY SHOULD BE MON. 

&&

.AVIATION /FOR THE 06Z TAF ISSUANCE/...

PLENTY OF MOISTURE WILL CONTINUE TO MOVE ACROSS THE AREA OVERNIGHT 
AND THU MORNING. BOTH SITES VIS HAVE NOT FALLEN AND NEITHER HAVE THE 
CIGS WHICH IS A SURPRISE ESPECIALLY AT SAW WITH A NORTH WIND BEING 
UPSLOPE. FEELING IS BOTH SITES WILL GRADUALLY DETERIORATE A BIT 
OVERNIGHT AS MOISTURE AND UPSLOPE TAKE OVER AND WILL STAY AT 
IFR/LIFR. AS THE LOW SLIDES EASTWARD THURSDAY...AND NORTHWESTERLY 
WINDS TAKE HOLD...EXPECT IMPROVEMENT AT SAW THU AFTERNOON. EXITING 
DEEPER MOISTURE WILL ALSO BRING CMX BACK TO MVFR CONDITIONS LATE 
THURSDAY MORNING/EARLY THURSDAY AFTERNOON.

&&

.MARINE /FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE/...

LOW PRESSURE ACROSS FAR NORTHERN LAKE HURON WILL SLOWLY SHIFT TO THE 
LOWER GREAT LAKES BY THURSDAY NIGHT AND FRIDAY...WITH 30KT WINDS 
POSSIBLE OVERNIGHT INTO THURSDAY IN BETWEEN THIS AND THE APPROACHING 
RIDGE COMING IN FOR FRIDAY FROM THE SOUTHWEST. DEVELOPING LOW 
PRESSURE ACROSS THE NORTHERN PLAINS SATURDAY SHOULD MOVE ACROSS THE 
UPPER GREAT LAKES LATE SATURDAY NIGHT...AND TO THE LOWER GREAT LAKES 
BY LATE SUNDAY. ON MONDAY...A RIDGE WILL BUILD ACROSS LAKE SUPERIOR 
FROM A LARGE HIGH PRESSURE SYSTEM IN THE CENTRAL AND SOUTHERN 
PLAINS. 

&&

.MQT WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

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