Area Forecast Discussion
Issued by NWS Marquette, MI

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FXUS63 KMQT 040703
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
303 AM EDT TUE AUG 4 2015

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 303 AM EDT TUE AUG 4 2015

UPPER AIR PATTERN CONSISTS OF A DEEP 500 MB TROUGH OVER THE EAST
HALF OF NORTH AMERICA WITH A CLOSED LOW OVER CENTRAL ONTARIO. UPPER
FLOW CONTINUES TO BE FROM THE NORTHWEST AND THE TROUGH AXIS WILL
SLOWLY MOVE EAST THIS FORECAST PERIOD.

WITH TROUGHING AND A WEAK SHORTWAVE PASSING THROUGH THE AREA
TODAY...KEEPING SLIGHT CHANCE POPS IN CONTINUES TO LOOK GOOD AND
WILL KEEP IN THE FORECAST. WILL CONTINUE A DRY FORECAST FOR TONIGHT.
OVERALL...DID NOT MAKE TOO MANY CHANGES TO THE GOING FORECAST FOR
TEMPERATURES. CLOUDS WILL SLOWLY DECREASE TODAY AND WITH MOSTLY
CLEAR SKIES AND LIGHT WIND TONIGHT...GOOD RADIATIONAL COOLING
CONDITIONS SET UP.

.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 341 PM EDT MON AUG 3 2015

BELOW AVERAGE TEMPERATUES AND A FEW SMALL CHANCES OF RAIN WILL BE
THE RULE ACROSS UPPER MI INTO THIS WEEKEND.

TUESDAY NIGHT...A MID-LEVEL LOW CENTERED OVER JAMES BAY WILL BEGIN A
SLOW PUSH EASTWARD TUESDAY NIGHT. ANY SHOWER ACTIVITY THAT OCCURS
DURING THE DAY TUESDAY AS AN ASSOCIATED TROUGH AXIS CROSSES UPPER MI
SHOULD END BY TUESDAY EVENING UNDER INCREASED DRYING AND DEEP
SUBSIDENCE. THE SFC GRADIENT WINDS WILL BECOME LIGHT/CALM AS A SFC
RIDGE BUILDS FROM SOUTH CENTRAL CANADA TO THE WESTERN CWA. WHILE
PWAT VALUES OF AROUND 0.75 INCHES WILL BE FAR FROM IDEAL FOR
SUBSTANTIAL COOLING...INLAND LOCATIONS SHOULD DROP WELL INTO THE 40S
GIVEN THE OVERALL COOL AIR MASS IN PLACE. UPPER 30S FOR THE TYPICAL
COLDEST SPOTS WILL NOT BE OUT OF THE QUESTION FOR THE INTERIOR WEST.
HAVE STEERED CLEAR OF THE COLDEST GUIDANCE FOR NOW AS ANOTHER WEAK
MID-LEVEL TROUGH CROSSING THE AREA OVERNIGHT MAY BE ENOUGH TO
PRODUCE SOME SCATTERED CLOUDS.

BY WEDNESDAY...THE MORNING LOOKS TO BE MOSTLY SUNNY...BUT YET
ANOTHER SUBLTE TROUGH LOOKS TO REACH THE WESTERN CWA LATE IN THE
AFTERNOON. A SHALLOW LAYER OF MOISTURE BETWEEN 800 AND 850 HPA
COMBINED WITH WEAK FORCING FROM THE TROUGH MAY BE ENOUGH TO PRODUCE
LIGHT SHOWERS. IF THIS OCCURS...THE FOCUS WILL BE ON A WEAK LAKE
SUPERIOR LAKE BREEZE...AND A LAKE MI/GREEN BAY LAKE BREEZE THAT
SHOULD PUSH WELL INLAND ON LIGHT EASTERLY WINDS. HAVE OPTED TO ADD A
SLIGHT CHANCE OF AFTERNOON SHOWERS FOR THE CENTRAL CWA AWAY FROM THE
GREAT LAKES AT THIS TIME.

THURSDAY...A SHORTWAVE TROUGH ERODING A RIDGE OVER THE NORTHERN
PLAINS TUESDAY NIGHT IN CONJUNCTION WITH THE RIGHT ENTRANCE OF AN
UPPER JET WILL INDUCE MULTIPLE AREAS OF CONVECTION ACROSS THE
NORTHERN PLAINS INTO THE MID/UPPER MS VALLEY WED. LATEST GUIDANCE IS
SPLIT ON THE INTENSITY OF THE NORTHERN SECTION OF THE
CONVECTION...WITH THE ECMWF BEING MOST AGRESSIVE. IT APPEARS ANY
NORTHERN CONVECTION WILL STRUGGLE TO TRACK WELL EAST ACROSS THE CWA
AS IT ENCOUNTERS AN INCREASINGLY DRIER AIR MASS ACROSS NORTHERN WI
AND WESTERN LAKE SUPERIOR. WIDELY ISOLATED SHOWERS/SPRINKLES COULD
OCCUR AS THE TROUGH AXIS PASSES THURSDAY MORNING...BUT CONFIDENCE IS
MUCH TOO LOW TO INTRODUCE ANY MENTION AT THIS TIME.

FRIDAY THROUGH MONDAY...THE EVOLUTION OF THE SYNOPTIC PATTERN
BECOMES MORE COMPLICATED BEGINNING LATE THIS WEEK. SIMPLY PUT...THE
LONG TERM MODELS ARE IN LITTLE AGREEMENT. IN FACT...THE 12Z RUN OF
THE GFS SHOWS A STACKED SHORTWAVE RIDGE OVER THE CWA AT 12Z
SAT...WHILE THE ECMWF HAS A MID-LEVEL TROUGH LAGGING BEGIND A SFC
TROUGH JUST EAST OF UPPER MI. MEANWHILE...THE CANADIAN GEM CANNOT
CHOSE WHICH OF THE OTHER TWO TO FOLLOW...WITH IT MORE IN LINE WITH
THE ECMWF THU INTO FRI...AND THE GFS SAT INTO SUN. MOST OF THIS IS A
RESULT OF THE ECWMF LEAVING BEHIND THE SW EXTENT OF THURSDAYS TROUGH
IN RESPONSE TO CONVECTIVE FEEDBACK ACROSS THE NORTHERN PLAINS. WILL
STILL HEDGE TOWARD A DRIER SOLUTION FOR MOST DAYS UNTIL THINGS WORK
THEMSELVES OUT IN THE GUIDANCE.
&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 121 AM EDT TUE AUG 4 2015

EXPECT QUITE A BIT OF LOW CLOUDS TO LINGER THRU THE MORNING AS THE
UPPER GREAT LAKES WILL BE DOMINATED BY A MOIST CYCLONIC NW FLOW
AROUND LOW PRES NEAR HUDSON BAY. ALTHOUGH VFR CONDITIONS SHOULD BE
THE RULE FOR THE MOST PART AT KIWD/KCMX/KSAW...CIGS MAY DROP INTO
THE HIGH END MVFR RANGE AROUND SUNRISE GIVEN CURRENT OBS UPSTREAM TO
THE NW OF LAKE SUPERIOR. EVEN IF CIGS DROP INTO THE MVFR CATEGORY...
DAYTIME HEATING AND LOW-LEVEL DRYING WILL ALLOW A RETURN OF VFR
CONDITIONS AT ALL TERMINALS BY LATE MORNING. UNDER DEEPER DRYING
DURING THE AFTN...EXPECT CLOUDS TO SCATTER OUT AT ALL TERMINALS.
WHILE ISOLD -SHRA AND/OR SPRINKLES ARE EXPECTED AT TIMES INTO THE
MORNING HRS...VFR VIS SHOULD PREVAIL.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 303 AM EDT TUE AUG 4 2015

EXPECT WNW WINDS UP TO 20 KTS INTO MID WEEK AROUND DEEP LOW PRESSURE
NEAR HUDSON BAY. A WEAK PRESSURE GRADIENT WILL DOMINATE DURING THE
LATE WEEK...RESULTING IN WINDS UNDER 20 KTS. NO GALES SEEN ANYTIME
SOON.
&&

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

$$

SHORT TERM...07
LONG TERM...KLUBER
AVIATION...ROLFSON
MARINE...07



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