000
FXUS63 KMQT 121934
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
334 PM EDT WED JUN 12 2013

.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 333 PM EDT WED JUN 12 2013

500MB LOW PRESSURE SITUATED OVER NORTHERN QUEBEC WILL SINK SOUTHWARD
THIS EVENING...SWINGING A WEAK SHORTWAVE ACROSS NORTHERN LAKE
SUPERIOR OVERNIGHT. IN THE MEANTIME AN UPPER LEVEL RIDGE BUILDING
OVER THE NORTHERN PLAINS WILL HOVER EASTWARD THROUGH THURSDAY.

AT THE SURFACE...A VERY WEAK LOW PRESSURE TROUGH HOVERS OVER MUCH OF
THE GREAT LAKES...AND THIS WILL SLIDE EASTWARD OVERNIGHT WITH THE
APPROACH OF A SURFACE HIGH FROM THE WEST. THIS PATTERN WILL LEAD TO
NORTH-NORTHWEST WINDS OVERNIGHT AND INTO THURSDAY. FOG THAT
DEVELOPED OVERNIGHT OVER MUCH OF NORTH CENTRAL AND EASTERN UPPER
MICHIGAN HAS CONFINED ITSELF OVER THE FAR NORTHEASTERN SECTIONS OF
THE LAKE AS OF 19Z THIS AFTERNOON. AS THE SHORTWAVE TROUGH SWINGS
THROUGH OVERNIGHT THE LL MOISTURE INCREASES. THE LL MOISTURE
COMBINED WITH NORTH-NORTHWESTERLY WINDS WILL BE ENOUGH TO KEEP THE
PATCHY FOG GOING IN THE LAKE SUPERIOR ZONES. EXPECT THAT THIS FOG
WILL MOVE CLOSER TO THE SOUTHERN LAKE SUPERIOR SHORELINE/MAINLY EAST
OF MUNISING TONIGHT.

MEANWHILE...THIS MORNING ON LAKE MICHIGAN FOG CROWDED INTO THE
NEARSHORE ZONES AND EVEN INTO NORTHERN GREEN BAY. THROUGH THE
AFTERNOON THE FOG BECAME MORE AND MORE PATCHY...BEFORE DISSIPATING
EVERYWHERE EXCEPT FAR NORTHERN LAKE MICHIGAN ZONES...MAINLY NEAR
MACKINAC COUNTY. HAVE DIMINISHED THIS FOG IN THE GRIDS AS WELL...AND
KEPT MAINLY PATCHY FOG OVER THE FAR NORTHERN LAKE MI ZONES. ANY
REMAINING FOG WILL LIKELY MOVE OFFSHORE AS WINDS INCREASE OUT OF THE
NORTH-NORTHWEST THIS EVENING.

THERE IS THE POSSIBILITY THAT THE FOG COULD BECOME MORE WIDESPREAD
AND DENSE OVERNIGHT TONIGHT WITH THE BATCH OF MOIST AIR MOVING OVER
THE LAKE...HOWEVER TOOK THE DENSE FOG ADVISORIES DOWN SINCE IT HAS
ALL BUT DISSIPATED AS OF 19Z. LATER SHIFTS WILL HAVE TO RE-ISSUE IF
VISIBILITIES DIMINISH TONIGHT.

INCREASED MOISTURE AND NORTHERLY FLOW THROUGH LATE EVENING COMBINED
WITH THE WEAK SUPPORT FROM THE UPSLOPE FLOW/THE SHORTWAVE SUGGESTS
THAT LIGHT DRIZZLE IS POSSIBLE IN THE HIGHER TERRAIN ACROSS NORTH
CENTRAL UPPER MICHIGAN. HAVE KEPT PATCHY DRIZZLE INTO THE NORTH
CENTRAL HIGHER TERRAIN ACCORDINGLY.

AS THE HIGH PRESSURE INCHES CLOSER...PWATS DIMINISH TO LESS THAN 70
PERCENT OF NORMAL...AND WINDS INCREASE OUT OF THE NORTHWEST...EXPECT
ANY LINGERING PATCHES OF FOG TO DISSIPATE. WITH THE TIGHTER PRESSURE
GRADIENT NORTHWEST WINDS WILL REACH 10 TO 20 KNOTS OVER CENTRAL AND
EASTERN LAKE SUPERIOR...LEADING TO WAVES AROUND 3 TO 4 FEET CLOSE TO
SHORE. MID SHIFT WILL LIKELY NEED TO PUT UP A MODERATE SWIM RISK FOR
ALGER AND PERHAPS EVEN MARQUETTE COUNTY /MAINLY BECAUSE OF THE FAR
EASTERN PORTIONS OF THE COUNTY/...THOUGH IT WILL BE MARGINAL.

.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 333 PM EDT WED JUN 12 2013

AREA WILL BE UNDER A BUILDING UPPER RIDGE /MOVING EAST OUT OF THE
NORTHERN PLAINS/ AS A SHORTWAVE QUICKLY DIVES SOUTHEAST OUT OF THE
LOWER GREAT LAKES THURSDAY AFTERNOON. MEANWHILE...HIGH PRESSURE
FROM WESTERN ONTARIO WILL DROP SOUTHEAST OVER THE UPPER GREAT LAKES
ON THURSDAY NIGHT AND REMAIN INTO FRIDAY. THIS SHOULD LEAD TO A DRY
PERIOD OF WEATHER FOR THE AREA WITH HIGH CLOUDS STREAMING EAST INTO
THE AREA LATE THURSDAY NIGHT INTO FRIDAY. FIRST...LOWS ON THURSDAY
NIGHT WILL BE ON THE COOL SIDE AS SKIES WILL BE MOSTLY CLEAR AND
PWATS ARE 35-40 PERCENT OF NORMAL. WINDS WILL DIMINISH FASTER OVER
THE WEST HALF UNDER THE RIDGE...SO THEY WILL BE THE COOLEST AND
HAVE LOWS IN THE UPPER 30S. THE LINGERING GRADIENT OVER THE EAST
SHOULD LEAD TO A SLOWER COOL DOWN AS WINDS STAY UP FOR MOST OF THE
NIGHT. ADDED A MENTION OF FROST TO THE TRADITIONAL COLD SPOTS OF
EASTERN ONTONAGON AND SOUTHERN HOUGHTON COUNTIES...BUT OVERALL
SHOULDN/T BE ANYTHING SIGNIFICANT AND HAVE LEFT OUT OF THE HWO DUE
TO THE SMALL AREA. THE MAIN CONCERN FOR FRIDAY WILL BE THE DEEP
MIXING PRODUCING LOW RH VALUES. MIXED LAYER DEWPOINTS FROM THE
MODELS INDICATE VALUES POTENTIALLY FALLING INTO THE LOWER 20S.
HAVEN/T TRENDED THE FORECAST THAT FAR...BUT DID LOWER THEM INTO THE
UPPER 20S OVER PORTIONS OF EASTERN UPPER MICHIGAN. THIS WILL
PRODUCE MINIMUM RH VALUES IN THE 20S FOR MOST INTERIOR
LOCATIONS...WITH THE LOWEST VALUES AROUND 20 OVER THE EAST.
FORTUNATELY...WINDS WILL BE LIGHT UNDER THE HIGH...BUT LAKE BREEZES
COULD PRODUCE SOME HIGHER WINDS FOR A PERIOD IN THE AFTERNOON.

FOR FRIDAY NIGHT INTO THE WEEKEND...THE FORECAST WILL COME DOWN TO
HOW QUICKLY THE TROUGH CURRENTLY OVER THE PACIFIC NORTHWEST CAN
PUSH EAST AND OVER THE UPPER RIDGE. LATEST TRENDS IN THE MODELS
SEEM TO BE FOR THE DRIER AIR TO WIN OUT...AS THE BETTER FORCING IS
HELD UP NEAR LAKE WINNIPEG THROUGH MUCH OF THE WEEKEND. IN
ADDITION...THE 850MB WARM FRONT HUNG UP IN SOUTHERN MINNESOTA
THROUGH NORTHEAST ILLINOIS WILL KEEP THE STRONGER STORMS IN THAT
AREA AND LIMIT THE NORTHEASTWARD EXTENT OF THE INSTABILITY AND
MOISTURE RETURN. THIS WILL LIKELY KEEP THE SHOWERS FAIRLY
ISOLATED/SCATTERED UNTIL THE SHORTWAVE AND LOW ARRIVES. WILL SHOW
SLIGHT AND LOW CHANCE POPS ARRIVING FROM THE WEST ON FRIDAY NIGHT AS
THE BROAD WARM AIR ADVECTION SLIDES EAST ACROSS THE AREA. EXPECT THE
STRENGTH OF THE SHOWERS TO DIMINISH SATURDAY AS IT MOVES EAST AND
RUNS INTO THE DRIER AIR FROM THE EXITING HIGH. AT LEAST FOR THE
WEEKEND PERIOD...THIS WILL LIKELY BE THE BEST SHOT FOR
PRECIPITATION. BEST INSTABILITY AND SHOWALTER VALUES ARE MAINLY TO
THE WEST OF THE AREA ON FRIDAY NIGHT BUT DO TRY TO BLEED INTO
WESTERN UPPER MICHIGAN ON SATURDAY MORNING.

ONCE THIS MID LEVEL WARM FRONT MOVES THROUGH...A DECENT AMOUNT OF
MID LEVEL DRY AIR /EML/ WILL MOVE IN AND DIMINISH PRECIPITATION
CHANCES THROUGH THE REST OF THE WEEKEND. THERE IS SOME UNCERTAINTY
ON THE PRECIP TIMING/CHANCES ON SATURDAY NIGHT AS A SURFACE TROUGH
LOOKS TO SWEEP THROUGH AND THERE MAY BE ENOUGH MOISTURE TO LEAD TO A
FEW SHOWERS...SO WILL KEEP SOME MENTION OF SLIGHT CHANCE POPS DUE TO
THAT PASSAGE. OTHERWISE...THINK THE CHANCES ARE LIMITED ON SUNDAY
AND WILL TRIM BACK POPS SLIGHTLY AND KEEP THE BEST CHANCES CONFINED
TOWARDS LAKE MICHIGAN WHERE THERE WILL BE BETTER MOISTURE. AS WE GET
CLOSER TO THE WEEKEND...HOPEFULLY WE WILL BE ABLE TO FINE TUNE THE
POPS SOME TO GIVE A BETTER IDEA OF TIMING AND THE DRY PERIODS.

SHORTWAVE FINALLY ROUNDS OR BREAKS DOWN THE RIDGE ON SUNDAY
AFTERNOON. THIS WILL ALLOW THE SHORTWAVE AND ASSOCIATED WEAKENING
LOW TO DROP SOUTHEAST AND ACROSS THE UPPER GREAT LAKES ON SUNDAY
NIGHT AND MONDAY. THIS LOOKS TO BE THE BEST CHANCE FOR MORE
WIDESPREAD PRECIPITATION. WILL TREND THE POPS UP SOME FOR THAT TIME
PERIOD...BUT STILL KEEP IT IN THE CHANCE CATEGORY. BEHIND THE LOW
AND SHORTWAVE...AREA WILL BE UNDER NORTHWEST FLOW FOR TUESDAY AND
WEDNESDAY. HIGH PRESSURE WILL LIKELY SETTLE INTO THE AREA AND KEEP
THE AREA DRY. AS FOR TEMPS THROUGH THE PERIOD...HIGHS LOOK TO BE
FAIRLY SEASONABLE.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 120 PM EDT WED JUN 12 2013

THOUGH HIGH PRESSURE HAS KEPT CONDITIONS QUIET THIS AFTERNOON AT THE
TAF SITES...A LOW PRESSURE TROUGH WILL BRING NORTH-NORTHWESTERLY
WINDS WITH A COOLER...MORE MOIST AIRMASS IN OVERNIGHT. AS A
RESULT...EXPECT SOME LOWER CLOUD COVER. FEEL THAT THE BEST CHANCE
FOR IFR CONDITIONS ARE AT KSAW. EXPECT WITH UPSLOPE NORTHERLY
WINDS...INCREASED MOISTURE IN THE LOW LEVELS...AND WEAK SUPPORT FROM
THE PASSING SHORTWAVE CEILINGS COULD BECOME BORDERLINE IFR-MVFR AND
WE COULD EVEN SEE SOME PATCHY DRIZZLE. HIGH PRESSURE WILL RETURN
WITH DRY AIR TOMORROW AFTERNOON...SO THESE CONDITIONS SHOULD END BY
THE EARLY AFTERNOON TIME FRAME.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 333 PM EDT WED JUN 12 2013

HIGH PRESSURE WILL SLIDE OVER THE GREAT LAKES FROM THURSDAY
AFTERNOON INTO SATURDAY EVENING. NORTH-NORTHWEST WINDS WILL DEVELOP
THURSDAY AFTERNOON BUT WILL REMAIN BELOW 20 KNOTS. LOW PRESSURE WILL
PASS OVER NORTHERN LAKE SUPERIOR SUNDAY AND MONDAY HOWEVER WINDS ARE
NOT EXPECTED TO EXCEED 15 KNOTS. HIGH PRESSURE WILL RETURN FOR THE
START OF THE WORK WEEK...KEEPING WINDS LIGHT.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...MCD
LONG TERM...SRF
AVIATION...MCD
MARINE...MCD