Area Forecast Discussion
Issued by NWS Detroit/Pontiac, MI

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FXUS63 KDTX 290352
AFDDTX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
1152 PM EDT SUN JUN 28 2015


.AVIATION...

WEAK HIGH PRESSURE WILL SUSTAIN LIGHT WINDS AND CLEAR SKIES BELOW 8K
FT THROUGH DAYBREAK. RESIDUAL HIGH BASED SHOWERS ACROSS THE SAGINAW
VALLEY WILL CONTINUE ON THE DOWNWARD TREND OVER THE NEXT COUPLE OF
HOURS. LOW PRESSURE OVER THE MID MS VALLEY WILL LIFT INTO OHIO MON
AFTERNOON. THIS SYSTEM WILL BRING RAIN TO THE REGION...ESPECIALLY
METRO DETROIT LATE MON AFTERNOON INTO THE EVENING. CEILINGS WILL IN
TURN BEGIN A GRADUAL LOWERING TREND AS THE RAIN SPREAD INTO METRO
DETROIT.

//DTW THRESHOLD PROBABILITIES...

* HIGH IN CIGS AOB 5KFT AFTER 23Z MONDAY.

* LOW IN THUNDERSTORMS MONDAY AFTERNOON AND EVENING.

&&

.PREV DISCUSSION...ISSUED 309 PM EDT SUN JUN 28 2015

SHORT TERM...LATE THIS AFTERNOON AND TONIGHT

IT LOOKS TO BE MOSTLY CLEAR TO PARTLY CLOUDY TONIGHT AS SOUTHEAST
MICHIGAN WILL BE CAUGHT IN BETWEEN TWO STORM SYSTEMS. THE LARGER ONE
CENTERED ALONG THE SOUTHERN ONTARIO/QUEBEC BORDER...WITH THE SECOND
UPPER WAVE OVER THE MIDWEST DIVING INTO THE WESTERN OHIO VALLEY
TONIGHT. TRAILING UPPER LEVEL PV TAIL WORKING THROUGH EASTERN LOWER
MICHIGAN THIS AFTERNOON...AND THERE REMAINS A CHANCE FOR ISOLATED
SHOWERS AS MID LEVELS (700-500 MB) ARE RELATIVELY COOL...AND LAPS
DATA INDICATED AT LEAST A COUPLE HUNDREDS OF CAPE. HOWEVER...SURFACE
DEW PTS CONTINUE TO FALL ACROSS NORTHERN LOWER MICHIGAN INTO THE
40S...AND THERE HAS BEEN NO DEVELOPMENT (THROUGH 3 PM) OUTSIDE OF
MODERATE CU FIELD WEST/NORTHWEST OF SAGINAW. STILL...THIS IS THE
MIDDLE OF SUMMER AND CAN`T GIVE UP UNTIL VERY LATE IN THE DAY...AND
WITH MANY OF THE 12Z MODELS STILL SUGGESTING A FEW SHOWERS...WILL
CARRY ISOLATED MENTION FOR TRI-CITES DOWN TO AROUND FLINT AS MARINE
PUSH OFF SAGINAW BAY WITH WATER TEMPS IN THE UPPER 60S TO NEAR 70
DEGREES POSSIBLY HELPS CONTRIBUTE SOME MOISTURE OR AT THE VERY LEAST
BOOSTING LOW LEVEL CONVERGENCE.

BASED OFF DEW PTS AND WINDS GOING VERY LIGHT/CALM...GUIDANCE TEMPS
IN THE 50S APPEARS FINE...WITH NORMALLY COLDER THUMB REGION CLOSER
TO 50 DEGREES. ENOUGH DRYING HAS OCCURRED THIS AFTERNOON TO LIMIT
FOG POTENTIAL...OUTSIDE THE USUAL SUSPECTS/MICRO-CLIMATES.

LONG TERM...MONDAY THROUGH NEXT SUNDAY

COMPOSITE PV ANOMALY STRUCTURE OVER THE MID-MISSISSIPPI VALLEY IS
ATTEMPTING TO CONSOLIDATE WITH THE AID OF DIABATICS. DEFORMATION
ALONG THE COLD FLANK HAS BEEN RESPONSIBLE FOR SOME MODEST CONVECTIVE
DEVELOPMENT OVER CENTRAL WISCONSIN. NEAR THE WAVE CENTROID...
CONVECTION IS BEING FORCED OVER EASTERN IOWA INTO CENTRAL ILLINOIS.
THIS ACTIVITY SHOULD CONTINUE TO ORGANIZE THROUGH THE EVENING HOURS
AS THE WAVE PIVOTS CYCLONICALLY IN THE LONG WAVE TROUGH STRUCTURE.

28.12Z NWP SUITE OFFERING THE FULL SPECTRA OF POSSIBLE OUTCOMES IN
SPITE TIME GETTING SHORT. THE NAM AND GEM REGIONAL BOTH PRESENT A
VERY BULLISH RESULT FOR FAR SOUTHEAST MICHIGAN WITH DEFORMATION
FORCED CONVECTION AND APPRECIABLE PRECIPITATION. WATER VAPOR IMAGERY
DOES NOT SEEM TO SUPPORT THE OVERALL STRUCTURE DISPLAYED IN THESE
TWO SOLUTIONS. THE GFS AND LATEST ECMWF BOTH KEEP THE BEST FORCING
AND INSTABILITY SOUTH OF LOWER MICHIGAN. EXPECT SOME SHOWER AND
LIMITED THUNDERSTORM ACTIVITY TO AFFECT THE FAR SOUTH. STILL
PRESENTED SOME MODEST CHANCES FARTHER NORTH...WHERE BROAD
DEFORMATION COULD COLLECT SOME MOISTURE AND INITIATE SOME SHOWER
ACTIVITY.  SUFFICE IT TO SAY...PRECIP CHANCES ARE RECEDING QUICKLY
AS DETAILS REGARDING THE SYSTEM STRUCTURE CONTINUE TO EMERGE.

THE SAME IS TRUE FOR THE NEXT WAVE EXPECTED TO INFLUENCE THE REGION
ON TUESDAY - MOST OF THE MOISTURE CONVERGENCE WILL REMAIN ON THE
PERIPHERY OF THE REGION...WHERE BETTER MOISTURE AND INSTABILITY WILL
BE PRESENT. THE PRESENCE OF A SURFACE LOW DURING THE DIURNAL CYCLE
DOES COMMAND A LITTLE RESPECT FOR SOME SCATTERED SHOWER
DEVELOPMENT...BUT ONLY A LITTLE RESPECT.

WEDNESDAY INTO NEXT WEEKEND...MEAN UPPER TROUGHINESS LOOKS TO
CONTINUE OVER THE GREAT LAKES BETWEEN RATHER STAGNANT RIDGING OVER
THE DESERT SOUTHWEST AND THE CENTRAL ATLANTIC. WITH SHORTWAVES
ROTATING THROUGH AND THE UPPER COOL POOL IN THE VICINITY...CHANCE
POPS ARE WARRANTED FOR MUCH OF THIS TIME FRAME SAVE FOR THURSDAY
WHEN INDICATIONS ARE THAT BRIEF SHORTWAVE RIDGING WILL TAKE PLACE.
PREDICTABILITY NOT HIGH YET FOR THE 4TH WITH 12Z GFS DEVELOPING A
CUTOFF LOW OVER THE LOCAL AREA WHILE ECMWF PUSHES A WAVE THROUGH
EARLIER LEADING TO A DRY PROJECTION.

MARINE...

BRIEF RESPITE FROM GUSTY WIND CONDITIONS TONIGHT AND EARLY MONDAY.
THE NEXT STORM SYSTEM WILL SET THE STAGE FOR AN INCREASE IN SURFACE
FLOW MONDAY EVENING. ON LAKE ERIE THE INITIAL INCREASE IN WINDS WILL
BE EASTERLY FLOW ON MONDAY AFTERNOON TRANSITIONING TO WESTERLY AS
THE SURFACE LOW TRAVERSES THE LAKE. LAKE HURON WILL EXPERIENCE
SLIGHLY WEAKER FLOW WITH THE OPPOSITE ATTITUDE WITH NORTHEASTERLY
BACKING TO NORTHERLY. THE STRONGEST FLOW APPEARS RESTRICTED TO LAKE
ERIE WITH THE EASTERLY FLOW EPISODE.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY FROM 6 PM MONDAY TO 4 AM EDT TUESDAY FOR
     LEZ444.

&&

$$

AVIATION.....SC
SHORT TERM...SF
LONG TERM....MANN/DT
MARINE.......MANN


YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).



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