Area Forecast Discussion
Issued by NWS Marquette, MI

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FXUS63 KMQT 300817
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
417 AM EDT WED JUL 30 2014

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 352 PM EDT TUE JUL 29 2014

A SHORTWAVE TROUGH IS CURRENTLY JUST NW OF LAKE SUPERIOR WITH A SFC
TROUGH STRETCHING FROM WRN LAKE SUPERIOR TO ERN UPPER MI. SHOWERS
AND THUNDERSTORMS ARE ALONG AND S OF THE SHORTWAVE...WITH THUNDER
LESS WIDESPREAD IN THE SHOWERS THAT ARE ALONG THE SFC TROUGH ACROSS
SCENTRAL UPPER MI AND NERN WI. 500-1000J/KG OF SKINNY CAPE AND 0-6KM
BULK SHEAR OF 20-25KTS ARE ANALYZED...HIGHEST ALONG THE SRN/SWRN
BORDER OF THE CWA. TENDENCY WILL BE FOR THE CONVECTION TO SINK S
WITH THE SHORTWAVE/SFC TROUGH AND DWINDLE AS DAYTIME HEATING
DIMINISHES. THINK THAT SMALL HAIL AND GUSTY WINDS ARE THE MAIN
THREAT WITH THE STORMS...BUT COULD SEE A STORM OR TWO SEE NEARLY
MARGINALLY SEVERE HAIL.

ADDED FOG OVER MAINLY ERN LAKE SUPERIOR THROUGH TOMORROW AS FOG IS
SEEN ON SATELLITE AND THE GRAND MARAIS WEBCAM...ALONG WITH A SHIP
OBSERVATION.

SIMILAR SETUP FOR WED AFTERNOON...BUT THE SHORTWAVE LOOKS TO MOVE
OVER THE CENTRAL/ERN CWA. MLCAPE VALUES AROUND 500J/KG /AGAIN WITH
SKINNY CAPE/ WILL BE A BIT LOWER THAN TODAY...BUT 0-6KM SHEAR LOOKS
TO BE 30-35KTS...SO EXPECTING SIMILAR NON-SEVERE STORMS FOCUSING
OVER MAINLY THE ERN HALF OF UPPER MI DURING THE AFTERNOON/EARLY
EVENING.

.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 414 AM EDT WED JUL 30 2014

UPPER LOW THAT HAS IMPACTED THE WEATHER PATTERN OVER THE GREAT LAKES
THIS WEEK PERSISTS THROUGH LATE THIS WEEK. UNTIL THE LOW LOSES ITS
INFLUENCE...FORECAST WILL CONTINUE TO FEATURE CHANCES OF MAINLY
AFTERNOON AND EVENING SHOWERS AND POSSIBLE THUNDERSTORMS THURSDAY
AND FRIDAY.

ON THURSDAY...WITH THE LOW STILL IN THE VCNTY OF JAMES BAY...NAM/GFS
/GEM-NH AND ECMWF ALL INDICATE BATCH OF HIGHER H7-H5 RH DROPPING
ACROSS THE UPR GREAT LAKES. SFC FRONT IN THE VCNTY OF UPR MICHIGAN
SHOULD LEAD TO LOW-LEVEL CONVERGENCE. TIMING OF THE FRONT WILL BE
IMPORTANT THOUGH AS IF THE FROPA IS QUICKER NNW WINDS WILL RESULT IN
MORE STABLE FLOW ACROSS MUCH OF CWA BY PEAK HEATING OF THURSDAY AFTN.
GEM-REGIONAL AND NAM QUITE ON BOARD WITH THAT IDEA INDICATING LITTLE
IF ANY SHRA/TSRA ON THURSDAY. WILL SHOW THE HIGHER POPS...ONLY LOWER
CHANCES...OVER THE FAR SCNTRL DURING THE AFTN WHERE GREATER CONVERGENCE
WOULD BE FM THE LARGER SCALE FRONT AND LK MICHIGAN LAKE BREEZE.
OVERALL THOUGH...SEEMS THAT MODELS ARE TRENDING AWAY FM MUCH IN WAY
OF SHRA/TSRA ON THURSDAY AS STABILIZING FLOW OFF LK SUPERIOR IS
DOMINANT FACTOR.

HIGH PRESSURE BEGINS TO SLIDE ACROSS LATER THURSDAY NIGHT. LOWERED
TEMPS INTO THE MID 40S FOR COOL SPOTS FOR THE INTERIOR. SOME FOG IS
POSSIBLE LATE THURSDAY NIGHT INTO DAYBREAK ON FRIDAY...ESPECIALLY
FOR AREAS THAT SEE RAIN ON THURSDAY AFTN. ON INTO THE DAYTIME ON
FRIDAY...GRADIENT NW/N FLOW IS NOT AS STRONG AS THURSDAY WITH THE
HIGH SETTLING OVERHEAD. RESULT WILL BE MORE LAKE BREEZES AND BETTER
SHOT AT INSTABILITY TO BUILD UP OVER INLAND AREAS DURING PEAK
HEATING OF THE DAY AS MAX TEMPS REACH MID 70S MOST AREAS. IF THERE
IS A DECENT SHORTWAVE OR POCKET OF ENHANCED MOISTURE/LIFT ROTATING
AROUND THE DEPARTING UPR LOW...AS THE LATEST ECMWF INDICATES...THEN
WOULD EXPECT MUCH GREATER COVERAGE TO THE SHOWERS AND BETTER SHOT AT
TSRA AS WELL GIVEN THE WARMER SFC TEMPS. BASED ON WHERE HIGHEST
MLCAPES ARE FORECAST AND WITH H7 WINDS FM NW...BEST CHANCE OF TSRA
WOULD BE ALONG WI BORDER OVER IRON/DICKINSON/MENOMINEE COUNTIES.

HEIGHTS RISE A BIT BY SATURDAY AS THE LOW BEGINS TO FILL AND SFC
HIGH SLIDES ACROSS AND THIS IS LOOKING LIKE A DRY DAY FOR THE MOST
PART. MORE TROUGHING ALOFT EXPECTED SUNDAY INTO EARLY NEXT WEEK. A
COUPLE SFC FRONTS CROSS THE AREA AS WELL WHICH SHOULD INCREASE CHANCES
FOR SHOWERS AND THUNDERSTORMS. CONSENSUS POPS SHOWING MID RANGE
CHANCE POPS SEEMED GOOD...MAXIMIZING ON SUNDAY AFTN THROUGH SUNDAY
EVENING...THEN AGAIN ON MONDAY AS MAIN FRONTAL PASSAGE OCCURS. GFS
AND GEM-NH POINT TO STRONGER STORMS MORE LIKELY ON MONDAY AS DEEP
LAYER SHEAR RAMPS UP OVER 30 KTS AND MLCAPES INCREASE TO 1000J/KG. ON
THE FLIP SIDE...ECMWF WOULD SUGGEST SUNDAY AFTN FOR STRONGER STORMS.
EITHER WAY...NEITHER DAY LOOKS LIKE A SURE BET FOR STRONG STORMS...WHICH
IS BASICALLY A PERSISTENCE FORECAST FOR THIS SUMMER THUS FAR IN TERMS
OF SEVERE WEATHER ACROSS UPR MICHIGAN.

HIGH PRESSURE BUILDS BACK OVER THE UPPER GREAT LAKES IN WAKE OF THE
TROUGH FOR TUESDAY AND WEDNESDAY RESULTING IN DRY WEATHER BY THAT
TIME. GENERALLY SEEMS THAT OVERALL PATTERN OF BELOW NORMAL TEMPS
WILL PERSIST INTO NEXT WEEK...THOUGH TREND WILL BE TOWARD ONLY
SLIGHTLY BELOW NORMAL TEMPS. DRIER THAN NORMAL PATTERN IS FORECAST
TO PERIST RIGHT ON THROUGH MID AUGUST PER MEDIUM RANGE MODELS AND
LATEST CPC FORECASTS.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 137 AM EDT WED JUL 30 2014

EXPECT FOG TO IMPACT ALL THE TAF SITES EARLY THIS MRNG WITH MID LVL
DRYING OVER THE LLVL MSTR...WITH CONDITIONS FALLING AS LO AS LIFR/
VLIFR MAINLY AT THE MORE SHELTERED SAW/IWD SITES. THIS FOG WL BURN
OFF AFT SUNRISE. MORE SHRA MAY THEN IMPACT CMX AND ESPECIALLY SAW IN
THE AFTN AS ANOTHER DISTURBANCE CROSSES ERN UPR MI IN THE PRESENCE
OF DAYTIME HEATING. ALTHOUGH ANY HEAVIER SHRA THAT MOVES OVER THESE
SITES COULD RESULT IN MVFR OR EVEN IFR CONDITIONS FOR A BRIEF
TIME...VFR WX WL PREDOMINATE. ANY SHRA WL DIMINISH IN THE EVNG
FOLLOWING THE DEPARTURE OF THE DISTURANCE AND LOSS OF DAYTIME
HEATING.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT
722 PM EDT TUE JUL 29 2014

WITH A WEAK PRESSURE GRADIENT TYPICAL OF SUMMER DOMINATING THIS
FORECAST PERIOD...EXPECT WINDS UNDER 20 KTS THRU THE WEEK.
&&

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

$$

SHORT TERM...TITUS
LONG TERM...JLA
AVIATION...KC
MARINE...TITUS




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