Area Forecast Discussion
Issued by NWS Marquette, MI

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

000
FXUS63 KMQT 301130
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
730 AM EDT SUN AUG 30 2015

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 343 AM EDT SUN AUG 30 2015

TODAY AND TONIGHT...MODELS SHOW THE MID-UPPER LEVEL RIDGE FROM
SOUTHERN ROCKIES INTO NORTHERN PLAINS BUILDING INTO THE UPPER GREAT
LAKES IN RESPONSE TO STRONG SHORTWAVE ENERGY MOVING INTO THE PACIFIC
NORTHWEST. STRONG WARM ADVECTION IN A WSW WIND FLOW WILL ALLOW 8H
TEMPS TO RISE ABOVE 20C OVER THE WESTERN CWA THIS AFTERNOON AND
ACROSS THE REST OF THE FORECAST AREA TONIGHT. THIS STRONG WAA AND DEW
POINTS IN THE LOWER 60S IN A SW FLOW WILL RESULT IN MUGGY CONDITIONS
WITH HIGH TEMPS TODAY GENERALLY IN THE LOWER TO MID 80S...EXCEPT FOR
COOLER 70S READINGS DOWNWIND OF THE BAY OF GREEN BAY AND NORTHERN
LAKE MI. A FEW DOWNSLOPING LOCATIONS NEAR LAKE SUPERIOR MAY REACH
INTO THE UPPER 80S WEST. LOWS TONIGHT ARE EXPECTED IN THE LOWER TO
MID 60S...WARMEST FOR DOWNSLOPING AREAS ALONG LAKE SUPERIOR.

GIVEN THE MOIST CONDITIONS EXPECT PATCHY FOG THIS MORNING AND THEN
REDEVELOPING PATCHY FOG OVERNIGHT TONIGHT...ESPECIALLY DOWNWIND FROM
LAKE MICHIGAN IN A SW FLOW.

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 355 AM EDT SUN AUG 30 2015

BROAD STRONG UPPER RIDGE AND ASSOCIATED WARMTH IS THE PROLONGED
PERIOD OF LATE SUMMER WARMTH IS WEATHER STORY THIS WEEK. GOOD
AGREEMENT FM MEDIUM RANGE MODELS THAT UPPER RIDGE BUILDS FM
SOUTHWEST CONUS TO UPPER GREAT LAKES ON MONDAY SANDWICHED IN BETWEEN
BROAD TROUGHING FM ALASKA TO WESTERN CANADA/PACIFIC NORTHWEST AND
ANOTHER AREA OF TROUGHING OVER NORTHERN QUEBEC AND THE CANADIAN
MARITIMES. H85 TEMPS SURGING UPWARDS OF +20C ON MONDAY AND A STEADY
SRLY WIND SUPPORT HIGHS NEARING 90 DEGREES OVER WEST CWA WITH MID-
UPR 80S ELSEWHERE...EXCEPT FOR TYPICAL COOLING NEAR LK MICHIGAN.

UPPER RIDGE FLATTENS SLIGHTLY BY TUESDAY AS SHORTWAVE AND ASSOCIATED
STRONGER SFC LOW CROSS MANITOBA AND NW ONTARIO. MAY SEE TAIL END OF
THAT SHORTWAVE ENERGY HAVE BETTER CHANCE AT TRIGGERING AT LEAST
ISOLD SHRA/TSRA WITH MLCAPES TO 1500J/KG AND UPTICK IN MOISTURE
ALONG WEAK DECAYING SFC FRONT AND LAKE BREEZES. PULSE TYPE STORMS
COULD OCCUR WITH DEEP LAYER SHEAR UP TO 30 KTS AND DCAPES 500-
1000J/KG. SOUNDINGS OVERALL PRETTY DRY WITH JUST A NARROW MOIST
LAYER AROUND H8 AND SOME CAPPING H8-H7. THOSE FACTORS SHOULD HOLD
DOWN COVERAGE OF SHRA/TSRA TO ISOLATED. SLIGHT CHANCE POPS SEEM GOOD
WITH THIS PATTERN. ANOTHER WARM AND HUMID DAY WITH HIGHS WELL INTO
THE 80S. COULD SEE AFTN/EVENING SHRA/TSRA WEDNESDAY AS WELL.
HOWEVER...SHORTWAVE AND ASSOCIATED LIFT APPEARS LESS THAN TUESDAY SO
WILL KEEP POPS AT SLIGHT CHANCE AND NOT OVER AS MUCH AREA AS
TUESDAY. H85 TEMPS NEARING +20C AGAIN SO SHOULD SEE MAX TEMPS BACK
TOWARD 90 DEGREES FOR PORTIONS OF CWA AWAY FM LK MICHIGAN.

GFS QUITE STRONGER THAN ECMWF OR GEM-NH WITH SHORTWAVE LIFTING
THROUGH ON THURSDAY. QPF FM GFS MORE WIDESPREAD...LIKELY DUE TO
STRONGER WARM AIR ADVECTION AND THETA-E ADVECTION THAN OTHER MODELS.
29AUG/18Z GFS RUN WAS SIMILAR...SO THERE IS SOME CONSISTENCY. 00Z
ECMWF IS JUST AS AGAINST THE STRONGER WAVE IDEA. THE UPPER LEVEL
WAVE CAUSING THIS COMMOTION IN THE MODEL SOLN STILL OVER PACIFIC
ATTM...SO REALLY TOUGH TO TELL IF THE IDEA IS FEASIBLE. WILL STAY
CLOSE TO CONSENSUS WHICH DOWNPLAYS GFS LED IDEA AND RESULTS IN
SLIGHT CHANCE POPS. AS LONG AS CLOUDS AND RAIN ARE NOT BIGGER
ISSUE...TEMPS SHOULD END UP SIMILAR TO READINGS ON WEDNESDAY AS THE
WARM START TO SEPTEMBER CONTINUES.

DECENT AGREEMENT THAT UPPER RIDGE STRENGTHENS FRIDAY AS TROUGHING
DIGS AS FAR SOUTH AS CA/NV. H85 TEMPS 18-24C...WARMEST GFS...WOULD
SUPPORT READINGS INTO AT LEAST LOW 90S AWAY FM ANY LK MICHIGAN
MODIFICATION. GFS EVEN SHOWS +24C OVER WESTERN CWA AND IF THAT
VERIFIES...COULD SEE HIGHS AS WARM AS THE MID 90S. ECMWF STAYING
MORE IN THE 18-20C RANGE SO WILL NOT GO MORE THAN NEAR 90 DEGREES
ATTM. EDGE OF UPPER LEVEL RIDGE...LIKELY JUST WEST AND NORTH OF UPR
LAKES...BECOMES FOCUS FOR SHRA/TSRA ACTIVITY BY NEXT WEEKEND AS
UPPER TROUGHING OVER WESTERN CANADA AND PACIFIC NORTHWEST SLIDES
TOWARD PLAINS AND INTERSECTS PWATS OVER 1.5 INCHES IN RIBBON FM
CNTRL PLAINS TO NORTHWEST ONTARIO AND QUEBEC. ESSENTIALLY THIS
HIGHER THETA-E AIR WILL RESIDE ALONG COLD FRONT SLOWLY MOVING
ACROSS NORTHERN PLAINS AND UPPER MISSISSIPPI RIVER VALLEY. FRONT
WILL BE SLOW MOVING AS IT WILL RUN PARALLEL TO UPPER LEVEL HEIGHTS.
EXPECTED PATTERN AND BLEND OF MODELS INDICATES COULD SEE REMNANT
SHRA/TSRA TRYING TO SNEAK OVER UPR LAKES FRIDAY INTO SATURDAY...BUT
MAJORITY OF CONCENTRATED SHRA/TSRA WOULD STAY WEST. GIVEN THE
INSTABILITY FORECAST AROUND BY THAT POINT THOUGH /MUCAPES THROUGH H7
WELL OVER 2000 J/KG ON THE TYPICALLY MORE CONSERVATIVE ECMWF/ CWA
WILL BE CLOSE ENOUGH TO HAVE SLIGHT CHANCES FOR SHRA/TSRA AS EVEN
SUBTLE FORCING COULD PROVIDE TRIGGER FOR ELEVATED AND/OR SFC BASED
SHRA/TSRA. NO CHANGE TO THE HEAT...WITH MORE WARM AND HUMID WEATHER
EXPECTED THROUGH THE WEEKEND. BREAK IN THE HEAT LOOKS TO ARRIVE ON
LABOR DAY AND EVEN MORE SO IN THE DAYS FOLLOWING.
&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 727 AM EDT SUN AUG 30 2015

LIFR/IFR CONDITIONS IN FOG/STRATUS AT TAF SITES SHOULD LIFT TO VFR
BY 14Z. VFR CONDITIONS SHOULD THEN CONTINUE THROUGH THE REST OF THE
PERIOD. &&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 343 AM EDT SUN AUG 30 2015

EXPECT PERIODS OF SW WINDS TO NEAR 20 KTS TODAY INTO MONDAY
NIGHT...ESPECIALLY OVER WESTERN AND NORTH CENTRAL LAKE SUPERIOR.
OTHERWISE...A GENERALLY WEAK PRES GRADIENT WILL DOMINATE THE UPPER
LAKES INTO NEXT WEEK. ON MOST DAYS...WINDS WILL BE UNDER 15KT.
&&

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

$$

SHORT TERM...VOSS
LONG TERM...JLA
AVIATION...VOSS
MARINE...VOSS



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.