FXUS63 KAPX 010743 AFDAPX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 345 AM EDT SUN AUG 1 2010 .SYNOPSIS.../ISSUED AT 345 AM/ OTHER THAN SOME SCATTERED SHOWERS AND THUNDERSTORMS TODAY IN THE FAVORED AREAS OF NORTHEAST LOWER AND INTERIOR SECTIONS OF EASTERN UPPER MICHIGAN...DRY WEATHER IS EXPECTED TO PREVAIL THROUGH AT LEAST THIS EVENING AS WEAK HIGH PRESSURE SETTLES OVER THE NORTH WOODS. A STORM SYSTEM ORGANIZING OVER THE NORTHERN PLAINS...WILL PUSH INTO THE WESTERN LAKES MONDAY...BEFORE EXITING EAST OF THE REGION TUESDAY. THIS SYSTEM WILL RETURN SHOWERS TO NORTHERN MICHIGAN MONDAY THROUGH TUESDAY. HIGH PRESSURE REDEVELOPS OVER THE UPPER MIDWEST AND NORTHERN LAKES BY MID WEEK...KEEPING NORTHERN MICHIGAN MILD AND DRY INTO NEXT WEEKEND. MSB && .SHORT TERM.../ISSUED AT 345 AM/...TODAY HIGH PRESSURE TO THE EAST IS EXTENDING WEAK RIDGING INTO NORTHERN MI. A WARM FRONT IS IN THE OHIO VALLEY...WITH A WAVE ON THE FRONT NEAR LOUISVILLE. A SUBTLE INVERTED TROF EXTENDS NORTHWARD FROM THE LOW TOWARD SE LOWER MI. EVENING/EARLY OVERNIGHT SHRA IN CENTRAL LOWER MI ARE NEARING SAGINAW BAY. PARTIAL CLEARING HAS OCCURRED IN EASTERN UPPER MI AND WITHIN 30 MILES OF LAKE MI. THERE IS A TOUCH OF FOG OUT THERE...MAINLY WHERE SKIES HAVE CLEARED. ONGOING SHRA IN THE SE...FUELED BY 10-15KT SW 850MB WINDS...WILL LIKELY PROVE DIFFICULT TO SHOVE OFFSHORE. 500MB FLOW REMAINS DIFFLUENT OVER NE LOWER MI. AND LOW LEVEL CONVERGENCE WILL INCREASE AFTER SUNRISE...AS WEAK TROFFING DEVELOPS NORTHWARD INTO CENTRAL LOWER MI...AND ONSHORE WINDS TRY TO GET ESTABLISHED. NAM ADVERTISES A SOGGY MORNING NEAR TAWAS BAY...AND THOUGH IS PROBABLY OVERDONE...SOME POPS ARE CERTAINLY IN ORDER THERE THRU 15Z. CLEARING WILL LIKEWISE SLOWLY...SLOWLY...PROGRESS EASTWARD THIS MORNING. BY AFTERNOON AN 80/65 PARCEL NEAR ATLANTA RESULTS IN 1100J/KG OF MLCAPE THIS AFTERNOON. THAT SEEMS A REASONABLE PARCEL...NEEDING ONLY A 15-20F DIRUNAL RISE. THAT IS CONSIDERABLY MORE INSTABILITY THAN PROGGED AT THIS TIME YESTERDAY. GIVEN NEGLIGIBLE WIND BELOW 850MB AND THUS AMPLE OPPORTUNITY FOR LAKE BREEZES...ACTUALLY FEEL SOMEWHAT MORE CONFIDENT THAT SCT SHRA/TSRA WILL DEVELOP IN NE LOWER THIS AFTERNOON. WILL ALSO CONTINUE WITH SCT POPS IN CHIPPEWA CO...AS A LAKE SUPERIOR LAKE BREEZE TRIES TO FIGHT INLAND AGAINST BACKGROUND SW SYNOPTIC WINDS THERE. MAX TEMPS LOW-MID 80S NW LOWER MI...NEAR 80 EASTERN UPPER/NE LOWER. JZ && .LONG TERM.../ISSUED AT 345 AM/...TONIGHT AND BEYOND TONIGHT...MODELS (NAM IN PARTICULAR) LINGERS SHRA IN NE LOWER MI THRU 06Z...SUPPORTED IN PART BY WEAK 850MB WARM/MOIST ADVECTION. NOT QUITE WILLING TO GO AS WET...BUT WILL ADD AN ISOLATED POP TO PARTS OF NE LOWER FROM 00Z-03Z. AN UPSTREAM COLD FRONT WILL WORK INTO NORTHERN MN AND JUST NORTH OF SUPERIOR OVERNIGHT. LOW LEVEL SW FLOW JUST AHEAD OF THE FRONT WILL INCREASE (850MB WINDS TO 20-25KT). A QUASI-WARM FRONT MAY ALSO DEVELOP EASTWARD ACROSS UPPER MI OVERNIGHT. THIS FACTORS WILL COMBINE TO PRODUCE ONE OR MORE MCS/S NEAR LAKE SUPERIOR OVERNIGHT INTO MONDAY MORNING. NAM/GFS HAVE BOTH TRENDED SOUTHWARD WITH THE DEVELOPING WARM FRONT AND THUS PRECIP DEVELOPMENT. THOUGH STILL EXPECTING THE BULK OF THE ACTIVITY OVER THE LAKE ITSELF...THAT ISN/T QUITE AS CERTAIN NOW. WILL ADD A CHANCE OF TSRA TO MOST OF EASTERN UPPER MI AFTER 06Z/2AM...EXCEPTING THE IMMEDIATE STRAITS AREA AND DETOUR/DRUMMOND. ELSEWHERE...A PARTLY CLOUDY NIGHT...WITH SOME FOG OVERNIGHT IN THE INTERIOR OF NORTHERN LOWER. MIN TEMPS ON THE MILD SIDE...NEAR 60 TO THE MID 60S. MONDAY...MAIN PRECIP CONCERNS WILL REMAIN IN THE NORTHERN PORTION OF THE FORECAST AREA...AS UPPER RIDGING/WARMING FROM THE SW WILL CHOKE OFF ATTEMPTS AT CONVECTION IN THE SOUTH. THE UPSTREAM COLD FRONT MAKES LITTLE IF ANY PROGRESS DURING THE DAY...BUT NEITHER DOES AN EAST-WEST ORIENTED QUASI-WARM FRONT STRETCHED OUT ACROSS UPPER MI. GIVEN LATE-NIGHT MCS ACTIVITY...A LEFTOVER BOUNDARY SHOULD BE LAID DOWN ANYWAY...THOUGH PRECISE LOCATION STILL UNCERTAIN. THE WARMING ALOFT IS MUCH SLOWER THAT FAR NORTH. SO EASTERN UPPER MI WILL MAINTAIN A PRECIP THREAT THRU THE DAY...DECAYING MCS REMNANTS IN THE MORNING...AND/OR CONVECTION REDEVELOPMENT IN THE PM. AMOUNT OF HEATING (AND THUS INSTABILITY) A BIG QUESTION MARK...BUT NAM AT LEAST EXTENDS A RIBBON OF 700-900J/KG OF MUCAPE INTO CENTRAL CHIPPEWA CO LATE IN THE DAY. AT THE RISK OF EXCESSIVE FLIP- FLOPPING...WILL REINSERT THUNDER INTO THE LATE PM FORECAST. TO THE SOUTH...PARTLY TO MOSTLY SUNNY AND TOASTY. MAX TEMPS RANGE FROM NEAR 80 IN EASTERN UPPER...TO MID/UPPER 80S IN NORTHERN LOWER. MONDAY NIGHT/TUESDAY...A SERIES OF WEAK SHORTWAVES ZIPPING ACROSS SUPERIOR/UPPER MI WILL FLATTEN OUT THE UPPER RIDGE OVER THE SOUTHERN LAKES. THIS WILL EVENTUALLY ALLOW A WEAK COLD FRONT AND PERHAPS A PRE-FRONTAL TROF TO ENTER THE FORECAST AREA ON TUESDAY. HOWEVER... THIS ALL LOOKS TO OCCUR SLOWER THAN EARLIER PROGGED. WILL BACK OFF ON SOUTHWARD EXPANSION OF PRECIP CHANCES...KEEPING THE FAR SE DRY ALL OF MONDAY NIGHT. HOWEVER...WILL ALSO NEED TO BE SLOWER IN DRYING THINGS OUT FROM THE NW ON TUESDAY. IT/S A VERY MUSHY PRESSURE PATTERN REGARDLESS...AND THERE/S NOT MUCH PUSH BEHIND THE FRONT TO SPEAK OF. WILL STILL HAVE EASTERN UPPER MI/STRAITS AREA DRYING OUT BE AFTERNOON...BUT WONDER IF EVEN THAT IS OPTIMISTIC. MIN TEMPS MAINLY MID 60S...MAX TEMPS NEAR 80 NORTH TO MID/UPPER 80S SOUTH. JZ TUESDAY NIGHT THROUGH SATURDAY...STILL LOOKING LIKE AN UNEVENTFUL STRETCH OF WEATHER ACROSS THE NORTH WOODS BEHIND TUESDAY'S FRONTAL PASSAGE...WITH POTPOURRI OF HIGH RESOLUTION AND ENSEMBLE GUIDANCE SUGGESTING MAINTENANCE OF DRY WEST TO NORTHWEST MID AND UPPER LEVEL FLOW...AUGMENTED NICELY DOWN LOW BY ELONGATED...SLOW MOVING...HIGH PRESSURE. COMBINATION OF ABOVE CONTINUES TO SUGGEST GENERALLY CLEAR SKIES THROUGH THE ENTIRE PERIOD. NO SIGNIFICANT TEMPERATURE ADVECTION PROCESSES EXPECTED...SUGGESTING TEMPERATURES RUNNING AROUND EARLY AUGUST CLIMO. MSB && .MARINE.../ISSUED AT 345 AM/ HIGH PRESSURE TO OUR EAST WILL TEND TO MAINTAIN SOUTHERLY FLOW THRU MOST THE FORECAST. HOWEVER...THESE WINDS WILL BE LIGHT...TO THE POINT OF ALLOWING PERIODS OF LIGHT/VARIABLE CONDITIONS...AND AFTERNOON ONSHORE LAKE BREEZES. A WEAK COLD FRONT WILL TRY TO WORK IN FROM THE NW ON TUESDAY. NO MARINE HEADLINES ANTICIPATED. JZ && .AVIATION.../ISSUED AT 1252 AM/...VALID FOR 06Z TAFS RAIN SHOWERS CONTINUE TO MOVE EAST, BUT WILL STAY SOUTH OF APN. FOG AND LOW CLOUDS WILL BE THE MAIN CONCERN WITH THE TEMPERATURE/DEWPOINT SPREADS AROUND 0-2F AROUND THE REGION. SO CLOUDS WILL BEGIN TO BUILD DOWN OVERNIGHT AND THE VSBY WILL FALL SOME AT PLN AND APN WHICH ARE MORE PRONE TO FOG. AFTER DAYBREAK, THE FOG AND LOW CLOUDS WILL BURN OFF AND THE CIGS AND VSBYS WILL BE VFR THROUGH THE DAY AND INTO THE NEXT EVENING. JSL && .APX WATCHES/WARNINGS/ADVISORIES... MI...NONE. LM...NONE. LH...NONE. LS...NONE. && $$