Area Forecast Discussion
Issued by NWS Marquette, MI

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000
FXUS63 KMQT 281934
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
334 PM EDT TUE JUL 28 2015

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 606 AM EDT TUE JUL 28 2015

WV IMAGERY AND RAP ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH OVER
THE NRN ROCKIES AND HIGH PLAINS AND A RIDGE FROM THE SRN PLAINS
THROUGH THE GREAT LAKES REGION INTO NRN ONTARIO. WITHIN BASE OF MID-
LEVEL TROUGH A STRONG SHORTWAVE AND DEVELOPING CLOSED LOW WAS
LIFTING NE FROM ERN MONTANA INTO THE WRN DAKOTAS. INSTABILITY
(MUCAPES 1000-2000 J/KG) AND LIFT AHEAD OF SHORTWAVE AND ALONG ASSOC
FRONTAL BOUNDARY HAS SUPPORTED A LARGE MCS OVER THE ERN DAKOTAS AND
WRN MN EARLY THIS MORNING. BY COMPARISION...HIGH PRESSURE OVER THE
GREAT LAKES REGION HAS RESULTED IN GENERALLY CLOUD FREE AND QUIET
CONDITIONS OVER UPPER MI...ALTHOUGH NIGHTTIME TEMPS HAVE BEEN QUITE
WARM... GENERALLY IN THE 60S.

MODELS INDICATE CLOUDS AND POSSIBLY A FEW SHRA FROM DIMINISHING
CONVECTION WITH MCS TO WEST COULD SPREAD INTO WRN UPPER MI THIS
AFTERNOON. DESPITE POSSIBLE INCREASE IN CLOUDS...EXPECT ENOUGH
SUNSHINE BY AFTERNOON TO PUSH TEMPS INTO THE UPPER 80S AND LOWER 90S
AS MOST LOCATIONS AGAIN TODAY. WITH DAYTIME MIXING EXPECT DEWPOINTS
TO LOWER INTO MID TO UPPER 50S AT MOST LOCATIONS WITH EVEN A FEW
LOWER 50S DEWPOINTS POSSIBLE OVER EASTERN SITES. COMBINATION OF HIGH
TEMPS AND LOWERING OF DEWPOINTS WILL RESULT IN INLAND MIN RH/S
DROPPING INTO THE 30S OVER MUCH OF CENTRAL UPPER MI WITH EVEN SOME
MID TO UPPER 20S RH/S OVER THE ERN THIRD OF UPPER MI. THIS WILL
INCREASE FIRE WEATHER CONCERNS TODAY INTO THIS EVENING GIVEN RECENT
STRETCH OF DRY WEATHER. FORTUNATELY SOUTHERLY WINDS AHEAD OF FRONT
SHOULDN/T INCREASE TOO MUCH THROUGH THIS EVENING (GENERALLY LESS
THAN 20 MPH FOR GUSTS). WEST WINDS HOWEVER COULD GET GUSTY IN WAKE
OF FRONT ON WEDNESDAY.

FOCUSING ON PCPN CHCS THIS AFTERNOON INTO TONIGHT AS FRONTAL SYSTEM
FROM PLAINS WORKS ITS WAY ACROSS THE REGION TONIGHT INTO EARLY
WEDNESDAY. MODELS SHOW SOME DIFFERENCES IN FRONTAL TIMING WITH THE
REGIONAL GEM PERHAPS A BIT QUICKER WITH FRONT INITIALLY THAN
NAM...GFS OR ECMWF MODELS. DESPITE MINOR DIFFERENCES MODELS
GENERALLY SHOW COLD FRONT REACHING INTO WRN UPPER MI THIS
EVENING...INTO CENTRAL UPPER MI AROUND 12Z WED AND EXITING ERN UPPER
MI AROUND 18Z WED. MODELS CONSISTENT WITH IDEA THAT BEST DYNAMICS
(MID-LVL Q-VECT CONV) ASSOC WITH FRONTAL SYSTEM WILL BE LIFTING WEST
AND NORTH OF THE UPPER GREAT LAKES TONIGHT...TIED TO MOVEMENT OF
SHORTWAVE AND ASSOC MID-LVL CLOSED LOW WHICH LIFT NE INTO SRN
MANITOBA AND NW ONTARIO TONIGHT. AT SAME TIME...MODELS AND SREF
ENSEMBLE FIELDS INDICATE BEST MOISTURE/INSTABILITY STAYING SOUTH OF
UPPER MI INTO WI BY TIME FRONT MOVES THROUGH TONIGHT WITH MUCAPES
500 TO MAYBE 1000 J/KG FAR WEST IN THE EVENING DECREASING TO ONLY A
FEW HUNDRED J/KG EAST OVERNIGHT. COMBINATION OF BEST DYNAMICS MOVING
WELL TO NORTH AND BEST MOISTURE STAYING SOUTH HAS LED MOST OF
MODELS TO DEPICT MORE A SCATTERED TO BROKEN LINE OF CONVECTION
DEVELOPING ALONG FRONT AS IT MOVES THROUGH UPPER MI TONIGHT. GIVEN
THE UNCERTAINTY WITH DEVELOPING CONVECTION ALONG FRONT HAVE
GENERALLY KEPT ONLY HIGH CHC POPS AND LIMITED LIKELY POPS IN FCST
FOR SCT SHRA/TSRA LATE THIS AFTERNOON/EARLY EVENING WEST SPREADING
ACROSS REST OF FCST TONIGHT.

ALSO DOWNPLAYED THREAT OF SEVERE STORMS IN HWO GIVEN LATER TIMING OF
FRONT TOWARD LATE EVENING OVERNIGHT AS INSTABILITY WILL BE WANING.
ALSO BEST DEEP SHEAR LOOKS TO LAG BEHIND THE FRONT AND OUT OF SYNC
WITH BETTER INSTABILITY.

.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 333 PM EDT TUE JUL 28 2015

IMPACTS...MAIN IMPACTS WILL BE ASSOCIATED WITH GUSTY WINDS WED NIGHT
AND THU.

THE OVERALL PATTERN AFFECTING THE AREA WILL NOT CHANGE MUCH
REGIONALLY THROUGH THE LONG TERM. A LOW PRESSURE SYSTEM OVER FAR NRN
ONTARIO AT 00Z THU WILL MOVE TO HUDSON BAY BY 00Z FRI AND MEANDER
OVER THE BAY INTO THE WEEKEND. THE LOW WILL THEN BEHIND THE CYCLE
BACK TO THE W...POSSIBLY BRINGING AN UPPER TROUGH OVER THE AREA LATE
THIS WEEKEND INTO NEXT WEEK.

THE PRESSURE GRADIENT...AND THEREFOR WINDS...WILL BE TIGHTEST OVER
THE AREA WED NIGHT...AND WILL GRADUALLY WEAKEN INTO SAT. WINDS GUSTS
AT 00Z THU WILL RANGE FROM 30-35MPH OVER THE KEWEENAW TO 10-20MPH
N/NE OF LAKE MICHIGAN. A TROUGH MOVES THROUGH WED NIGHT THAT MAY
LOCALLY ENHANCE WINDS OVER/NEAR LAKE SUPERIOR...BUT WINDS WILL
GENERALLY BE STRONGEST AT 00Z THU AND GRADUALLY DIMINISHING AFTER
THAT. ANOTHER MOISTURE STARVED TROUGH OR TWO MOVES THROUGH ON
THU...BUT WILL ONLY PROVIDE SOME INCREASED CLOUD COVER.

A SHORTWAVE WITH LIMITED MOISTURE MOVES THROUGH THU NIGHT...WHICH
JUSTIFIES SLIGHT CHANCE POPS AS MODELS SHOW LIGHT QPF AMOUNTS OVER
MUCH OF THE AREA.

FRI INTO SAT LOOKS DRY...ALTHOUGH THE 12Z/28 GFS DOES BRING A PRECIP
PRODUCING SHORTWAVE INTO THE AREA FRI NIGHT. LEFT PRECIP OUT OF THE
FORECAST SINCE THE PREVIOUS GFS RUN WAS DRY AND OTHER MODELS ARE
DRY.

TEMPERATURES THU THROUGH SAT WILL BE NEAR NORMAL WITH HIGHS IN THE
70S TO LOW 80S AND LOW IN THE 50S TO LOW 60S.

MODELS SHOW A MORE SIGNIFICANT SHORTWAVE AND WIDESPREAD QPF SAT
NIGHT INTO SUN SO WILL KEEP CHANCE POPS FOR THAT TIME FRAME. COOLER
TEMPS COME IN WITH THAT UPPER TROUGH EARLY NEXT WEEK...BRINGING
BELOW NORMAL TEMPS FOR A CHANGE.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 159 PM EDT TUE JUL 28 2015

HIGH CLOUDS WILL BEGIN TO LOWER THIS EVENING RIGHT AHEAD AND ALONG A
COLD FRONT CROSSING W TO E OVER THE AREA. WHILE THUNDERSTORMS WILL
BE POSSIBLE...THE TIMING AND OVERALL COVERAGE IS TOO SMALL TO
INCLUDE IN THE TAF RIGHT NOW. LLWS IS A CONCERN THIS EVENING INTO
THE EARLY MORNING HOURS WEDNESDAY AS WINDS JUST ABOVE THE SFC
CONTINUE AROUND 35KTS. EXPECT THE GUSTY WINDS TO MIX BETTER DURING
THE DAY...LIMITING THE NEED FOR LLWS. EXPECT SIGNIFICANT CLEARING
AND MIXING DIRECTLY BEHIND THE FRONT...WITH SOME SCT-BKN VFR CLOUDS
ENCROACHING BY MID AFTERNOON.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 159 PM EDT TUE JUL 28 2015

FOLLOWING THE PASSAGE OF A COLD FRONT LATE TONIGHT AND WED
MORNING...THE SHARPENING PRES GRADIENT OVER THE UPPER LAKES BETWEEN
HI PRES BUILDING INTO THE CENTRAL PLAINS AND LO PRES MOVING TOWARD
HUDSON BAY WILL SUPPORT WSW GALES UP TO 35 KTS THRU THE DAY ON WED
OVER THE W HALF OF THE LAKE...WHERE THE LAKE GEOGRAPHY TYPICALLY
ENHANCES THIS FLOW. MAINTAINED GOING GALE WATCH FOR THIS AREA.
ALTHOUGH THE GALES ARE EXPECTED TO DIMINISH ON WED EVENING... WINDS
UP TO 25-30 KTS WILL PERSIST THRU THU AS THE PRES GRADIENT SLOWLY
SLACKENS. LIGHTER WINDS UNDER 20 KTS WILL THEN BE THE RULE ON FRI
THRU THE WEEKEND AS A WEAKER PRES GRADIENT MORE TYPICAL OF SUMMER
DOMINATES THAT PERIOD.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
  GALE WATCH FROM WEDNESDAY MORNING THROUGH WEDNESDAY EVENING FOR
     LSZ162-240>247-263-264.

LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...VOSS
LONG TERM...TITUS
AVIATION...KF
MARINE...KC



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