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000
FXUS63 KMQT 170853
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
453 AM EDT MON JUN 17 2013

.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 411 PM EDT SUN JUN 16 2013

THE MAIN CONCERN FOR THE SHORT TERM FORECAST WILL BE THE ONGOING
SHOWERS AND THUNDERSTORMS AND ADDITIONAL SHOWERS WITH THE TROUGH
DROPPING SOUTH ACROSS THE AREA TONIGHT. INITIAL CONVECTION WAS OVER
EASTERN UPPER MICHIGAN...WHERE THERE WAS INCREASED MOISTURE FROM THE
FOG EARLIER TODAY AND CONVERGENCE FROM WEAK LAKE BREEZES. THESE
INITIAL SHOWERS HAVE SHIFTED TO THE SOUTHEAST AND OUT OF THE
CWA...BUT ARE SEEING SOME SHOWERS IN CENTRAL UPPER MICHIGAN ALONG
THE LAKE SUPERIOR LAKE BREEZE. THESE SHOWERS HAVE BEEN LIMITED THUS
FAR DUE TO THE DRY MID LEVEL AIR EVEN THOUGH THERE IS STRONG
LOW LEVEL LAPSE RATES AND RAP ANALYZED SB CAPE VALUES OF
500-1000 J/KG. BUT WITH THE INVERTED V LOOK TO THE RAP
SOUNDINGS...ML CAPES ARE STRUGGLING TO GET MUCH ABOVE 250-500 J/KG.
THIS DRY AIR CAN ALSO BE SEEN IN THE DEWPOINTS /UPPER 40S/ AWAY
FROM THE INFLUENCE OF THE GREAT LAKES. THERE HAVE EVEN BEEN SOME
SIGNIFICANT JUMPS IN THE DEWPOINTS OVER THE EASTERN CWA...AS THE
LAKE BREEZES HAVE MOVED IN AND OUT OF SOME OF THE SITES. FARTHER
WEST...A PERSISTENT SHOWER/THUNDERSTORM CLUSTER MOVED INTO WESTERN
GOGEBIC COUNTY OVER THE LAST HOUR AND DID PRODUCE SOME GUSTS UP TO
40KTS EVEN THOUGH THE CLUSTER IS DIMINISHING. THIS ISN/T TOO
UNREASONABLE WITH CURRENT DCAPE VALUES OVER MUCH OF UPPER MICHIGAN
AROUND 800-1000 J/KG AND THE INVERTED V SOUNDINGS. WOULD EXPECT
THIS TO BE THE PRIMARY CONCERN FOR ANY SHOWERS/THUNDERSTORMS LATE
THIS AFTERNOON AND EVENING. FINALLY...ADDITIONAL
SHOWERS/THUNDERSTORMS HAVE BEEN ONGOING JUST NORTHEAST OF LAKE
SUPERIOR...DUE TO ONE PIECE OF SHEARED OFF UPPER LEVEL ENERGY
DROPPING SOUTHEAST ALONG THE TROUGH. THESE SHOWERS WILL CONTINUE
QUICKLY SOUTHEAST AS THE STORM MOTION IS AROUND 40KTS.

THE AREA THAT WILL BRING THE BEST CHANCE FOR SHOWERS IS THE
REMNANT SHORTWAVE FROM THE UPPER LOW THAT WAS IN CENTRAL
SASKATCHEWAN YESTERDAY. THIS SHORTWAVE HAS STARTED TO MOVE TOWARDS
THE CANADA/ND/MN BORDER AND HAS SPARKED SHOWERS AND THUNDERSTORMS
ALONG THE SURFACE TROUGH WHERE THERE IS DEEPER MOISTURE. WITH THE
STORM MOTION TO THE SOUTHEAST AROUND 30-35KTS AND THE TROUGH SLOWLY
SAGGING SOUTHEAST...WOULD EXPECT THOSE SHOWERS TO MOVE SOUTHEAST
ACROSS WESTERN/CENTRAL UPPER MICHIGAN LATE THIS AFTERNOON AND INTO
THE EVENING HOURS. NOT ENTIRELY CONFIDENT ON THE EASTERN CWA...AS
IT WILL DEPEND ON THE THUNDERSTORMS CURRENTLY MOVING SOUTHEAST
FROM THUNDER BAY AND HOW FAR SOUTHEAST THEY WILL MAKE IT BEFORE
DIMINISHING. WILL HAVE LOWER POPS THAN OVER THE WEST...BUT STILL
IN THE LOW END CHANCE CATEGORY. AN EARLIER UPDATE COVERED THE
TIMING WELL OVER THE WEST AND HAVE JUST MADE MINOR TWEAKS TO
MATCH THE CURRENT CONDITIONS...WITH MOST AREAS IN THE HIGHER REACHES
OF THE SCATTERED/CHANCE CATEGORY. THINK THERE IS A DECENT SHOT MOST
LOCATIONS WILL SEE RAIN...BUT THE COVERAGE/TIMING WOULD BE BETTER
REFLECTED IN THE SCATTERED WORDING. AS MENTIONED ABOVE...THE DRY
AIR AND LIMITED INSTABILITY WILL BE THE MAIN LIMITING FACTORS TO
THE THUNDERSTORMS AND THEIR SEVERE POTENTIAL. BEST THREAT WILL BE
WEST-SOUTHWEST OF THE CWA WHERE THE 850-700/500MB LAPSE RATES ARE
THE STEEPEST...BUT THERE COULD BE SOME STRONGER STORMS OVER THE
SOUTHWEST THIRD OF THE CWA. HAIL POTENTIAL WILL BE LIMITED DUE TO
THE LIMITED INSTABILITY AND TALL/SKINNY CAPE. AS MENTIONED
ABOVE...GUSTY WINDS WILL BE THE BIGGEST THREAT OVER THE SW
HALF OF THE CWA...AS THEY HAVE THE STEEPER MID LEVEL LAPSE
RATES...COMBINED WITH THE DRY LOW LEVELS TO PRODUCE THE HIGHER
DCAPE VALUES.

THEN...AS THE SHORTWAVE TRACKS SOUTHEAST INTO NORTHWEST WISCONSIN
TONIGHT AND THE REST OF NORTHERN WISCONSIN ON MONDAY
MORNING...WOULD EXPECT SCATTERED SHOWERS TO CONTINUE THROUGH THE
NIGHT OVER THE SOUTHWEST HALF OF THE CWA. THAT IS ALSO WHERE
THE BEST 850-500MB Q-VECTOR CONV IS LOCATED EVEN THOUGH THE DEEPER
MOISTURE IS OVER EASTERN UPPER MICHIGAN. HAVE SLOWLY DIMINISHED THE
THUNDER THREAT OVERNIGHT AND INTO MONDAY MORNING TO BE OVER THE
SOUTHERN PART OF THE CWA...WHERE THE BETTER FORCING IS LOCATED. WILL
HOLD ON TO SOME LIGHT RAIN SHOWERS OVER NORTHERN UPPER MICHIGAN
OVERNIGHT TONIGHT AND INTO TOMORROW MORNING...AS LOW LEVEL
CONVERGENCE INCREASES WITH THE WINDS SHIFTING TO THE
NORTH-NORTHEAST. WITH DECENT MOISTURE BELOW 10KFT AS THAT
CONVERGENCE OCCURS...THINKING THERE WILL BE ENOUGH TO PRODUCE SOME
SHOWERS...ESPECIALLY OVER SOME OF THE HIGHER TERRAIN LOCATIONS OF
NORTH CENTRAL UPPER MICHIGAN WHERE THE WINDS BECOME UPSLOPE FOR A
PERIOD OF TIME.

THE LARGER SCALE FORCING SHOULD DEPART THE SOUTHWEST AND SOUTH
CENTRAL CWA AROUND DAYBREAK AND THEY WILL BE LEFT WITH ANY SHOWERS
DROPPING SOUTH ALONG THE ENHANCED CONVERGENCE. BEHIND THE
TROUGH...LOW CLOUDS SEEN IN CENTRAL ONTARIO/MANITOBA THIS MORNING
WILL MOVE SOUTH ACROSS THE CWA LATE TONIGHT INTO TOMORROW MORNING.
MODELS STRUGGLING WITH HOW LOW THE CLOUDS WILL BE...BUT EITHER WAY
A CLOUDY START TO THE WORK WEEK IS EXPECTED. CANADIAN HIGH PRESSURE
IS EXPECTED TO BUILD OVER THE AREA ON MONDAY AFTERNOON...BRINGING
DRIER AIR AND SUBSIDENCE TO THE AREA IN THE AFTERNOON. THIS WILL
PRODUCE DECREASING CLOUDS FROM NORTH TO SOUTH. HIGHS WILL BE MUCH
COOLER TOMORROW...WITH 60S IN MOST LOCATIONS EXCEPT NEAR LAKE
SUPERIOR WHERE NORTHERLY FLOW OFF THE LAKE WILL KEEP HIGHS IN THE
UPPER 50S.

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 452 AM EDT MON JUN 17 2013

TAKING A LOOK AT FCST SOUNDINGS...TUESDAY THROUGH EARLY WEDNESDAY
SHOULD BE PRETTY DRY WITH LITTLE TO NO CLOUDS IN THE SKY. WILL KEEP
THE 0 POPS GOING. OTHER THAN THE TYPICAL LAKE BREEZES...WITH HIGH
PRESSURE DIRECTLY OVERHEAD...WINDS WILL BE LIGHT. WILL LIKELY BE
ABLE TO MIX UP TO 800MB...OR HIGHER...RESULTING IN AFTERNOON RH
VALUES IN THE 20 PERCENT RANGE FOR MOST OF UPPER MI...FIRE CONCERNS
SHOULD REMAIN IN CHECK HOWEVER WITH THE RELATIVELY LIGHT WINDS.

EXPECT THE WARMING TREND TO CONTINUE INTO WEDNESDAY...WITH INCREASED
W-SW FLOW THROUGH 750MB...AS THE SFC HIGH SHIFTS TOWARD THE LOWER
GREAT LAKES. 850MB TEMPS SHOULD RISE FROM A CWA AVERAGE OF 7C
TUESDAY AFTERNOON TO AROUND 12C BY LATE WEDNESDAY AFTERNOON. WITH NW
FLOW ALOFT...EXPECT A FEW PESKY WAVES IN THE MEAN FLOW TO SLIDE
ACROSS THE CWA. THE NEXT SIGNIFICANT ONE WILL LINE UP WITH THE
NEARING OF A WEAK SFC LOW PUSHING OVER ONTARIO WEDNESDAY...AND INTO
QUEBEC LATE WEDNESDAY NIGHT INTO THURSDAY. THE WEAK COLD FRONT
SHOULD BE PRETTY WASHED OUT AS IT NEARS LAKE SUPERIOR WEDNESDAY
NIGHT. A FEW SHOWERS AND POSSIBLY THUNDERSTORMS ACROSS MN AND
WESTERN WI WEDNESDAY MORNING WILL LIKELY BE WINDING DOWN AS THEY
HEAD TOWARD UPPER MI. 200-500 J/KG CAPE VALUES OVER FAR W UPPER MI
BETWEEN 18Z WED AND 00Z THUR SHOULD BE ALL BUT GONE BY 06Z THURSDAY.
MOISTURE LOOKS TO BE VERY LIMITED...WITH ANY GOLF MOISTURE STUCK
ACROSS THE GULF STATES. EXPECT THE WEAK COLD FRONT TO SINK SOUTH OF
THE CWA BY THE END OF THE DAY THURSDAY. THE MAIN RESULT WILL BE
CLOUD COVER AND A WIND SHIFT...AND EVEN THROUGH WE DO HAVE 30-40
PERCENT POPS THEY WILL LIKELY RESULT IN LOW AMOUNTS OF PRECIP WITH
AROUND A TENTH OF AN INCH OR LESS EXPECTED FOR MOST LOCATIONS.

HIGH PRESSURE SET UP ACROSS MUCH OF N AND CENTRAL ONTARIO THURSDAY
MORNING WILL EXTEND A RIDGE ACROSS LAKE SUPERIOR BY LATE THURSDAY
MORNING...AND MUCH OF THE CWA BY 00Z FRIDAY. THE 500MB RIDGE ACROSS
THE PLAINS STATES WILL CONTINUE TO BUILD THURSDAY...IN ADVANCE OF
THE 500MB LOW STUCK SPINNING OVER THE PACIFIC NORTHWEST...AND SFC
LOW ORGANIZING OFF THE ROCKY MOUNTAIN FRONT. WENT AHEAD AND
BROKE UP THE THURSDAY NIGHT PERIOD TO INCLUDE A BIT MORE DRYING
WEATHER THURSDAY EVENING.

THE CLOSEST THE SFC LOW WILL LIKELY GET TO UPPER MI WILL BE MN AND S
WI...ON SATURDAY. STILL...MUCH OF OUR WEATHER FOR FRIDAY THROUGH THE
WEEKEND WILL REVOLVED AROUND THE 500MB FLOW WITH SEVERAL SMALLER
SCALE DISTURBANCES RESULTING IN A FEW TO SCATTERED SHOWERS AND
THUNDERSTORMS THROUGH THE REST OF THE PERIOD. THEY WILL REMAIN
DIFFICULT TO TIME UNTIL WE GET CLOSER TO THE WEEKEND.
&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 141 AM EDT MON JUN 17 2013

AN UPPER LEVEL DISTURBANCE WILL PRODUCE SHOWERS FOR KIWD AND POSSIBLY
KSAW OVERNIGHT. LIFR CLOUD DECK HAS ALREADY FORMED AT KCMX AND IT
LOOKS LIKE IT/S BEGINNING TO FORM AT KSAW IN UPSLOPE NE FLOW SO WILL
INCLUDE LIFR CLOUDS IN AT BOTH SITES FOR THE OVERNIGHT. BELIEVE IFR
TO LIFR CLOUD DECK WILL ALSO FORM AT KIWD BY 10Z AS WINDS SHIFT
TO ONSHORE NE DIRECTION. LOW CLOUDS WILL GRADUALLY LIFT BY LATE MON
MORNING BRINGING VFR CONDITIONS TO ALL TAF SITES.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 411 PM EDT SUN JUN 16 2013

WINDS ARE EXPECTED TO STAY BELOW 20KTS THROUGH THE PERIOD. A TROUGH
WILL DROP SOUTH ACROSS LAKE SUPERIOR THIS EVENING...LEADING TO WINDS
SHIFTING TO THE NORTH TONIGHT. AS THE TROUGH CONTINUES SOUTHEAST ON
MONDAY...HIGH PRESSURE WILL BUILD OVER THE UPPER GREAT LAKES AND
REMAIN THROUGH WEDNESDAY. A WEAK TROUGH WILL THEN APPROACH THE AREA
FROM THE NORTHWEST FOR THURSDAY. THERE IS A POCKET OF FOG OVER
EASTERN LAKE SUPERIOR /NEAR AND EAST OF GRAND MARAIS MI/ THAT HAS
BEEN DIMINISHING AND MOVING AROUND TODAY. WOULD EXPECT THE DRY AIR
TO CONTINUE TO EAT AWAY AT IT THIS EVENING...BUT THERE IS SOME
CONCERN IT COULD EXPAND WITH RAIN OCCURRING OVER CENTRAL LAKE
SUPERIOR THIS AFTERNOON/EVENING AND LINGER THROUGH THE NIGHT. IF FOG
DOES LINGER TONIGHT...IT WILL CLEAR OUT MON MORNING AS MUCH DRIER AIR
SURGES S INTO THE UPPER LAKES.
&&

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

$$

SHORT TERM...SRF
LONG TERM...KF
AVIATION...07/JV
MARINE...SRF