FXUS63 KDTX 251913 AAA

AFDDTX



AREA FORECAST DISCUSSION

NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI

315 PM EDT MON OCT 25 2004



.DISCUSSION...

PLENTY OF SUNSHINE AND BOUNDARY LAYER DRYING THIS AFTERNOON AS DRIER 

LOW AND MID LEVEL AIR CONTINUES TO FILTER INTO SOUTHEAST LOWER 

MICHIGAN. WATER VAPOR LOOP SHOWS THIS NICELY THIS AFTERNOON AND UA 

PLOTS INDICATING 925 MB TEMP/DEW POINT SPREADS INCREASING TO 20 

DEGREES. THIS WILL GIVE US A MOSTLY CLEAR EVENING OVER SOUTHEAST 

LOWER AND FOR MOST OF THE NIGHT. CLOUDS ASSOCIATED WITH COLD FRONT 

REALLY STRUGGLING AS UPPER WAVE MOVES NORTH TOWARD JAMES BAY AND 850 

MB FRONTOGENETICAL FORCING AND SURFACE CONVERGENCE WEAKEN. MAIN 

CONCERN FOR TONIGHT WILL BE FOG FORMATION AND POSSIBLE STRATUS OFF 

OF LAKE HURON LATE TONIGHT.



MODELS IN GOOD AGREEMENT OVER THE GREAT LAKES THROUGH 84 HOURS. GFS 

AND ETA AGREE THAT FRONTAL PASSAGE WILL BE DRY TONIGHT...THEN 

BUILDING UPPER RIDGE AND SFC RIDGE AXIS THROUGH THURSDAY AS 

CONFLUENT UPPER FLOW PERSISTS OVER THE NORTHERN GREAT LAKES AND 

SOUTHERN CANADA.



DO NOT ANTICIPATE FOG TO BE WIDESPREAD OR DENSE TONIGHT...GIVEN GOOD 

BOUNDARY LAYER DRYING THIS AFTERNOON. ALSO NOT MUCH COLD ADVECTION 

IN THE WAKE OF THE COLD FRONT...AND GOOD SURFACE DRY ADVECTION WITH 

DEW POINTS OVER EASTERN/CENTRAL WISCONSIN THE MID TO UPPER 30S. 

LOOKS LIKE THE 20 KM MESOETA SURFACE CONDENSATION PRESSURE DEFICITS 

ARE OVER DONE...SHOWING WIDESPREAD FOG OVER THE NORTH HALF OF THE 

CWA. MAY HAVE TO CONTEND WITH SOME STRATUS THOUGH OFF OF LAKE HURON 

AFTER 06Z...BUT THAT EVEN LOOKS MINIMAL. NORTHEAST FLOW DEVELOPS 

AROUND 09Z AND 925 MB TEMPS ONLY AROUND 4-5C...SO INSTABILITY OVER 

LAKE NOT IMPRESSIVE. 925 MB RH DOES INCREASE TO AROUND 95 PERCENT BY 

12Z THOUGH...SO ANTICIPATE SOME LAKE STRATUS AROUND DAYBREAK...THEN 

PERSISTING INTO TUESDAY MORNING...AND MIXING OUT INTO A STRATOCU 

DECK. NORTH HALF OF THE CWA WILL BE IMPACTED THE MOST WITH NORTHEAST 

FLOW. DO NOT SEE A GOOD EASTERLY COMPONENT UNTIL TUESDAY EVENING SO 

INLAND PENETRATION SHOULD BE CONFINED TO WEST HALF OF CWA ON TUESDAY. 

LOOKS LIKE 925 MB TEMPS WARM ENOUGH TO PRECLUDE WIDESPREAD 

STRATUS/LOW CLOUD ON TUESDAY NIGHT THOUGH. 



BUILDING UPPER RIDGE AXIS AND STRENGTHENING SURFACE HIGH WEDNESDAY 

AND THURSDAY WILL KEEP WARM AIR ADVECTION/OVERRUNNING SOUTH AND WEST 

OF THE CWA UNTIL FRIDAY. MODELS JUST INDICATING SCT/BKN ALTOCU DECK 

FOR WEDNESDAY AND THURSDAY...POPS REMOVED.



GFSLR SHOWING A SLOWER FRONTAL PASSAGE FOR FRIDAY AND SATURDAY...AND 

A LITTLE MORE CONSISTENT WITH CANADIAN GEM AND ECWMF MODELS. THIS 

SEEMS REASONABLE GIVEN THE AMPLITUDE AND STRENGTH OF DOWNSTREAM 

RIDGE AXIS AND LACK OF STRONG KICKER FOR SOUTHWEST U.S. CUTOFF.  



GUIDANCE TEMPERATURES LOOK TO WARM FOR TUESDAY...WITH LAKE CLOUD 

POTENTIAL.



&&



.DTX WATCHES/WARNINGS/ADVISORIES...NONE.



&&



$$



GSS



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