FXUS63 KAPX 220828 AFDAPX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GAYLORD MI 428 AM EDT WED MAY 22 2013 .SYNOPSIS... ISSUED AT 339 AM EDT WED MAY 22 2013 THE STORM SYSTEM WHICH SETTLED INTO THE PLAINS EARLIER THIS WEEK... WILL SLOWLY MOVE OVER THE GREAT LAKES TODAY...BEFORE FINALLY EXITING EAST ON THURSDAY. THIS PATTERN WILL CONTINUE TO GENERATE MILD TEMPERATURES TODAY...ALONG WITH CHANCES FOR SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WILL BUILD INTO THE GREAT LAKES FRIDAY AND SATURDAY. THIS PATTERN WILL GENERATE PLENTY OF SUN AND SEASONAL TEMPERATURES...OVER NORTHERN MICHIGAN THROUGH THE UPCOMING HOLIDAY WEEKEND. && .SHORT TERM...(TODAY THROUGH TONIGHT) ISSUED AT 339 AM EDT WED MAY 22 2013 CURRENTLY...PESKY UPPER LOW IS SPINNING OVER WESTERN MN WITH ASSOCIATED SFC LOW IN FAR NRN IL. LOW LEVEL TROUGHING EXTENDS FROM THIS LOW PRESSURE ACROSS NRN LOWER MICHIGAN. A LIGHT EASTERLY FLOW NORTH OF THIS TROUGHING...AND MOIST AIR OVER THE COLD LAKE WATERS...CONTINUES TO RESULT IN WIDESPREAD LOW CLOUDS...ALONG WITH AREAS OF DENSE FOG FOR A GOOD CHUNK OF FAR NRN LOWER MICHIGAN AND PORTIONS OF MACKINAC COUNTY IN EASTERN UPPER. A DENSE FOG ADVISORY HAS BEEN ISSUED. LOOKING BACK TO THE SOUTH...AND NEAR THE LOW PRESSURE...THERE WERE SHOWERS AND SOME STORMS FIRING OFF ALONG THE TROUGHING...FROM CENTRAL IL...TO AS FAR NORTH AS SW LOWER MICHIGAN. THESE SHOWERS HAVE BEEN ABLE TO FIRE WITH THE ASSISTANCE OF INCREASING UPPER LEVEL DIFFLUENT FLOW AND INCREASING -DIVQ IN WEAK SHORTWAVE ENERGY EJECTING FROM THE UPPER LOW. THROUGH DAYBREAK...AREAS OF DENSE FOG WILL GRADUALLY LIFT/THIN ENOUGH FOR THE ADVISORY TO END AROUND 8AM. THICKENING CLOUDS IN ADVANCE OF THE DEVELOPING SHOWERS WILL ASSIST MINIMAL SFC HEATING TO IMPROVE VISIBILITIES. AREAS OF DENSE FOG WILL STILL CONTINUE TO FLOAT AROUND THE COASTAL AREAS WHERE T/TD DEPARTURES WILL BE MINIMAL. AS WE HEAD THROUGH THE DAY AND NIGHT...STRONGER SHORTWAVE ENERGY WILL LIFT NE AND INTO LOWER MICHIGAN WITH SLIGHTLY DEEPENING SFC LOW PRESSURE THAT WILL CROSS THE THUMB LATE TONIGHT. NOT EXPECTING A WHOLE LOT OF HEATING TODAY WITH CLOUDY SKIES BEING RATHER DOMINANT. HIGH TEMPERATURES WILL MAINLY BE IN THE 60S TODAY WHICH WILL LEAVE MUCH TO BE DESIRED ON THE INSTABILITY FRONT. ONLY A FEW HUNDRED J/KG ARE EXPECTED...AND WILL OPT TO ONLY MENTION SOME ISOLATED THUNDERSTORMS FOR THE DAY...WITH SEVERE STORMS NOT EXPECTED. AS STRONGER SHORTWAVE ENERGY ARRIVES...SO DOES A NICE POCKET OF UPPER DIVERGENCE ASSOCIATED WITH A DOUBLE JET STRUCTURE ALOFT. THE OVERALL FORCING INCREASES TODAY...AND AM FULLY EXPECTING THE RADAR TO FILL IN WITH PERIODS OF/FAIRLY STEADY SHOWERS...AGAIN WITH SOME EMBEDDED THUNDER. AN INTERESTING FEATURE OF NOTE...IS A STRONG NRN STREAM SHORTWAVE AND COLD FRONT DROPPING SOUTH OUT OF FAR NRN ONTARIO. WITH MERGING SHORTWAVE ENERGY...A NOTICEABLE BAND OF ENHANCED PRECIPITATION IS LIKELY WITHIN DEVELOPING/STRENGTHENING LOW TO MID LEVEL FGEN. CAN SEE AN AXIS OF HIGHER QPF ALIGNING ITSELF ACROSS NRN LOWER LATER TODAY AND INTO TONIGHT...FROM MANISTEE THROUGH GAYLORD AND OFF TOWARD ROGERS CITY/ALPENA. UNCERTAIN AS TO HOW MUCH PRECIPITATION GETS INTO EASTERN UPPER...AS THE DOWNWARD BRANCH OF THE FGEN WILL LIKELY LEAD TO A SHARPER PRECIPITATION CUT OFF. MOST OF NRN CHIPPEWA COUNTY...POSSIBLY ALL OF CHIPPEWA COUNTY...COULD BE RAIN FREE. THESE DETAILS WILL HAVE TO BE HAMMERED OUT ON A MORE SHORT TERM BASIS. THE OW PRESSURE WILL EXIT NRN LOWER TOWARD THURSDAY DAYBREAK...BUT RAINS WILL LIKELY PERSIST THROUGH THE NIGHT ACROSS NRN LOWER. A TIGHTENING PRESSURE GRADIENT ON THE BACKSIDE OF THE DEPARTING LOW...WILL BRING GUSTIER NORTHERLY WINDS AND COLD ADVECTION. FOLKS ACROSS EASTERN UPPER AND FAR NRN/NW LOWER MICHIGAN...ESPECIALLY DOWNWIND OF THE GREAT LAKES WILL EXPERIENCE FAIRLY GUSTY WINDS. THIS INCREASED WIND WILL ALLOW FOG TO BECOME AN INCREASINGLY NON- ISSUE FROM NORTH TO SOUTH THROUGH THE NIGHT. && .LONG TERM...(THURSDAY THROUGH TUESDAY) ISSUED AT 339 AM EDT WED MAY 22 2013 THURSDAY...AS THE DAY STARTS OUT THE 500 MB TROUGH AXIS WILL STILL BE OVERHEAD, AND WITH THE DEFORMATION ZONE ON THE NE SIDE OF THE SFC LOW WILL EXPECT THAT RAIN SHOWERS WILL BE AROUND. HOWEVER, AS THE 500 MB TROUGH DROPS SE, THE DRY AIR BEHIND IT WILL BEGIN TO CLEAR THE SKY FROM NW TO SE THROUGH THE DAY. THE TEMPERATURES WILL END UP BEING CHILLY AS THE 850 MB TEMPERATURES APPROACH 0C BY 00Z. THE ONLY THING THAT WE HAVE GOING FOR US WILL BE THE MOSTLY SUNNY SKY IN THE AFTERNOON AS THE RH IN THE LOWER AND MID LEVELS OF THE ATMOSPHERE DRY OUT TO AROUND 10%. THIS WILL ALLOW US TO WARM UNDER FULL SUN. WITH THE SFC HIGH BUILDING IN THE REGION, WINDS SHOULD BEGIN TO SETTLE DOWN A BIT AS THE GRADIENT BEGINS TO SLACKEN BY EVENING. THURSDAY NIGHT...AS THE TEMPERATURES DIP TOWARD FREEZING, AND THE WINDS DIMINISH, WILL EXPECT THAT FROST WILL BE AN ISSUE. AT THIS POINT, HAVE PATCHY AND AREAS OF FROST, BUT IT MAY HAVE TO BE WIDENED AS THE TEMPERATURES HAVE A CHANCE TO FALL BELOW FREEZING. AT THIS POINT, THE MODELS ARE POINTING AT THE SFC TEMPERATURES FALLING TO A COUPLE DEGREES EITHER SIDE OF FREEZING AROUND MOST OF N MICHIGAN (E UPPER AND N LOWER). THINK THAT FROST ADVISORY WILL BE UPCOMING, BUT AT THIS POINT WITH THE GRADIENT WINDS HIGH ENOUGH, THINK THAT THE BOUNDARY LAYER WON'T ENOUGH FOR A WIDESPREAD FREEZE WARNING. SO NO HEADLINE AT THIS POINT. FRIDAY...HIGH PRESSURE CONTINUE OVER THE REGION AND KEEPS THE FORECAST AREA DRY. THE 850 MB TEMPERATURES BEGIN TO RECOVER SOME DURING THE DAY REACHING +2C OVER MOST OF THE FORECAST AREA BY 00Z. LOOKING AT THE MODEL SOUNDINGS BOTH THE GFS AND THE ECMWF MIX AROUND 850 MB. SO HAVE TEMPERATURES RISING TO EITHER SIDE OF 60 WITH FULL SUN AND MIXING TO 850 MB WOULD YIELD THOSE TEMPERATURES. OVERNIGHT, LOOKS LIKE ANOTHER POSSIBLE FROST NIGHT, ALTHOUGH NOT AS WIDESPREAD AS WOULD BE THOUGHT. BOTH THE GFS AND ECWMF ARE SUGGESTING THAT THERE COULD BE SOME CLOUD COVER, SO THAT FOR THE MOST PART, THE TEMPERATURES WOULDN'T FALL AS FAR, AND THE 850 MB TEMPERATURES ARE A LITTLE WARMER THAN THEY WERE ON THURSDAY NIGHT. EXTENDED (SATURDAY THROUGH TUESDAY)...SATURDAY, THE HIGH PRESSURE REMAINS IN PLACE AND CONTINUES TO KEEP THE PLACE DRY. SUNDAY, HIGH PRESSURE CONTINUES, SO THE WEEKEND ITSELF LOOKS GOOD FOR GETTING OUTSIDE. MONDAY, OVER N MICHIGAN LOOKS DRY. MODELS ARE STILL HOLDING FIRM FOR MOSTLY SUNNY. OVERNIGHT, THE CLOUDS BEGIN TO INCREASE. TUESDAY, THE CLOUDS KEEP INCREASING AND WITH THE SOUTH WIND, THE LOWER 70S WOULD BE EXPECTED FOR THE DAY. THERE COULD BE SOME THUNDER OVERNIGHT IN NW LOWER AS THE 500 MB RIDGE AXIS MOVES INTO THE FORECAST AREA, AND BECOMES THE LEADING EDGE OF THUNDERSTORMS. WILL HAVE ONLY A CHANCE FOR NOW, BUT IF THE MODELS CONTINUE THIS, THEN WEDNESDAY MORNING WILL BE THE BIGGEST SHOT. && .AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT) ISSUED AT 119 AM EDT WED MAY 22 2013 SUMMARY: LOW PRESSURE CURRENTLY OVER NORTHWEST IOWA WILL MOVE EAST...REACHING LOWER MICHIGAN LATE IN THE DAY WEDNESDAY. THIS WILL BRING A RENEWED ROUND OF SHOWERS AND POTENTIAL THUNDERSTORMS TO THE TERMINALS BY LATE MORNING/EARLY AFTERNOON WEDNESDAY...CONTINUING THROUGH THE END OF THE TAF PERIOD. RESTRICTIONS: DIFFICULT FORECAST IN THE SHORT TERM TO SAY THE LEAST. EVENING RAIN HAS IMPACTED ALL SITES EXCEPT MBL...AND BELIEVE THAT AT IFR /CIGS AND VSBYS/ WILL CONTINUE AT PLN/APN. LOWER CONFIDENCE AT TVC...BUT WILL KEEP THEM IFR AS WELL BASED ON NEAR TERM GUIDANCE AND OBS TRENDS. DO EXPECT THAT WE/LL SEE SOME IMPROVEMENT DURING THE MORNING WEDNESDAY...BUT WITH SHRAS ARRIVING BY AFTERNOON THIS WILL LIKELY BE SHORT-LIVED. IFR CIGS EXPECTED TO RE-DEVELOP AT ALL TERMINALS BY 00Z THURSDAY. THUNDERSTORM CHANCES LOOK QUITE SMALL WITH NO SEVERE EXPECTED. GIVEN THE LOW LIKELIHOOD OF ANY OF THE TERMINALS EXPERIENCING THUNDER...WILL NOT INCLUDE IN THIS TAF PACKAGE. WINDS: CALM TO LIGHT AND VARIABLE OVERNIGHT WILL BECOME LIGHT EAST TO NORTHEAST ON WEDNESDAY /5-10KTS/ GRADUALLY BACKING MORE NORTHERLY WEDNESDAY EVENING AROUND 10KTS. && .MARINE... ISSUED AT 339 AM EDT WED MAY 22 2013 MOIST AIR OVER THE COLD LAKE WATERS...ALONG WITH WEAK WINDS CONTINUE TO RESULT IN AREAS OF DENSE FOG OVER MUCH OF NORTHERN LAKE HURON...THE STRAITS AND NRN LAKE MICHIGAN. NOT EXPECTING MUCH LESS AS WE HEAD THROUGH THE DAY...ALTHOUGH SOME IMPROVEMENT IS EXPECTED THROUGH THE DAY. THIS FOG WILL GET SCOURED OUT LATER TONIGHT...BUT WITH ANOTHER MARINE ISSUE DEVELOPING. A TIGHTENING PRESSURE GRADIENT BEHIND A DEPARTING LOW PRESSURE AND ARRIVAL OF MUCH COLDER AIR/COLD FRONT...WILL RESULT IN DECREASING STABILITY AND POTENTIAL GALE FORCE GUSTS AND DEFINITE ADVISORY LEVEL GUSTS. HIGH PRESSURE WORKS IN OVER THE LAKES LATE THURSDAY NIGHT AND THROUGH FRIDAY FOR CALMER WINDS. THIS HIGH LINGERS INTO ALL OF THE WEEKEND. && .APX WATCHES/WARNINGS/ADVISORIES... MI...DENSE FOG ADVISORY UNTIL 8 AM EDT THIS MORNING FOR MIZ015>019- 021-024. LH...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 2 AM EDT FRIDAY FOR LHZ345>347. GALE WATCH FROM LATE TONIGHT THROUGH THURSDAY AFTERNOON FOR LHZ348-349. LM...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 2 AM EDT FRIDAY FOR LMZ341. GALE WATCH FROM LATE TONIGHT THROUGH THURSDAY AFTERNOON FOR LMZ323-342-344>346. LS...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 2 AM EDT FRIDAY FOR LSZ321-322. && $$ SYNOPSIS...JL SHORT TERM...SD LONG TERM...JL AVIATION...ARNOTT MARINE...SD