Area Forecast Discussion
Issued by NWS Marquette, MI

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000
FXUS63 KMQT 011110
AFDMQT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
710 AM EDT FRI AUG 1 2014

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 432 AM EDT FRI AUG 1 2014

THE FORECAST CONTINUES TO REVOLVE AROUND THE UPPER LOW SPINNING
NEAR THE SOUTHERN TIP OF JAMES BAY AND ASSOCIATED SHORTWAVES
DROPPING THROUGH THE AREA. AS SEEN THE LAST COUPLE OF NIGHTS...THE
PLUME OF HIGHER MOISTURE ON WV IMAGERY IS STRETCHING FROM NORTHWEST
ONTARIO TO NORTHEAST LAKE SUPERIOR AND EAST INTO NORTHEASTERN
ONTARIO. THIS MOISTURE PLUME AND A VERY SUBTLE SHORTWAVE HAS
PRODUCED A FEW SHOWERS OVER THE EASTERN HALF OF LAKE SUPERIOR EARLY
THIS MORNING THAT HAVE BEEN SLOWLY DIMINISHING AND DROPPING
SOUTHEAST TOWARDS EASTERN UPPER MICHIGAN. EXPECT MAINLY CLOUDS TO
CONTINUE TO THE EAST-SOUTHEAST THROUGH DAYBREAK BEFORE SHIFTING OUT
OF THE AREA A COUPLE HOURS AFTER SUNRISE. ELSEWHERE...SKIES HAVE
BEEN MOSTLY CLEAR AND TEMPERATURES ARE IN THE UPPER 40S AND LOWER
50S. THERE HAVE BEEN A FEW REPORTS OF PATCHY GROUND FOG...WITH THE
LOWEST VALUE AT KISQ WHERE THERE MAY BE SOME MOISTENING HELP FROM
LAKE MICHIGAN.

MUCH OF THE CWA WILL SEE MOSTLY SUNNY SKIES TO START THE DAY...BUT
THAT WILL GIVE WAY TO DIURNAL CLOUD DEVELOPMENT OVER THE INTERIOR
LAND AREAS TODAY. THERE IS CONCERN ON THE AMOUNT OF MOISTURE WITH
THE SHORTWAVE (CURRENTLY IN NORTHWEST ONTARIO) THAT WILL MOVE
THROUGH THE CWA THIS AFTERNOON. DEEPEST MOISTURE IN THE MODELS IS
CONFINED LARGELY TO THE SOUTH CENTRAL AND ESPECIALLY AREAS ALONG THE
WISCONSIN BORDER EAST OF WATERSMEET. LATEST TRENDS IN THE MODELS
INDICATE A LITTLE LESS MOISTURE THAN THE LAST COUPLE DAYS...WHICH
MAY TRY TO LIMIT EXTENT OF SHOWERS. HI-RESOLUTION MODELS CONSISTENT
ON THE IDEA OF CONVECTION LARGELY BEING CONFINED TO THE SOUTH
CENTRAL AND POTENTIALLY ALONG THE LAKE SUPERIOR/MICHIGAN LAKE BREEZE
CONVERGENCE OVER THE EAST. THOSE MODELS SEEM TO HAVE BEEN PERFORMING
THE BEST OVER THE LAST SEVERAL DAYS IN THIS PATTERN...SO WILL TEND
TO FOLLOW THAT IDEA WITH THE HIGHEST POPS (40-50 PERCENT) OVER
DICKINSON/MENOMINEE COUNTIES AND THEN TAPERED OFF TO SLIGHT CHANCES
SURROUNDING THAT AREA (KEEPING THE AREA NORTHWEST OF LINE FROM
WATERSMEET TO CHAMPION DRY AND ALSO BEHIND THE LAKE SUPERIOR LAKE
BREEZE. THE AREA ALONG THE LAKE BREEZE IN NORTH CENTRAL UPPER
MICHIGAN IS LIKELY THE BIGGEST CHANGE TO THE FORECAST...AS MODELS
HAVE INDICATED THE BREEZE PUSHING WELL INLAND (TOWARDS CHAMPION TO
GWINN). THUS...WITH THE STORM MOTION VECTORS INDICATING A SOUTHEAST
MOVEMENT AT 15KTS WOULD EXPECT THE SHOWERS TO BE FARTHER INLAND AND
TRIMMED NORTHERN EXTENT OF THE POPS IN MARQUETTE COUNTY AND
ELSEWHERE EAST ALONG LAKE SUPERIOR. AS DIURNAL HEATING IS
LOST...THE SHOWERS SHOULD QUICKLY DIMINISH.

MLCAPE VALUES OVER THE SOUTH CENTRAL CWA ARE IN THE 200-700 J/KG
RANGE...WHICH WOULD LEAD TO THE POTENTIAL FOR SOME THUNDER IN THAT
AREA. AS FOR THE STRENGTH...0-6KM SHEAR IS ONLY AROUND 20KTS
AND WILL HELP KEEP STORMS UPRIGHT. IF THERE IS A SUSTAINED
UPDRAFT...WOULD THINK SOME SMALL HAIL WOULD BE POSSIBLE (ESPECIALLY
ALONG THE WISCONSIN BORDER) EVEN THOUGH NCAPE VALUES ARE BELOW
0.1. THAT SMALL HAIL POTENTIAL IS LARGELY DUE TO THE LOWER WET BULB
ZERO HEIGHTS (AROUND 7.5KFT).

BEHIND THE SHORTWAVE TONIGHT...EXPECT ANOTHER QUIET NIGHT WITH
MOSTLY CLEAR SKIES. LIGHT WINDS DUE TO WEAK HIGH PRESSURE RIDGE
DEVELOPING OVER THE CWA WILL ALLOW LOWS TO ONCE AGAIN RANGE FROM
THE UPPER 40S TO LOWER 50S. WILL CONTINUE TO SHOW THE PATCHY GROUND
FOG OVER THE CENTRAL/EAST...ESPECIALLY WHERE RAIN IS POSSIBLE THIS
AFTERNOON.

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 335 AM EDT FRI AUG 1 2014

MAIN FCST CONCERNS IN THE LONG TERM ARE SHOWER/TS CHCS ASSOCIATED
WITH THE PASSAGE OF SHRTWVS EMBEDDED IN PERSISTENT NW FLOW ALF THAT
WL LINGER INTO THE COMING WEEK BTWN A MEAN UPR RDG OVER THE ROCKIES
AND A TROF IN QUEBEC. TIMING THESE SHRTWVS IS DIFFICULT AND LOWERS
THE OVERALL CONFIDENCE IN THE PCPN FCST. TEMPS THRU THE NEXT WEEK WL
GENERALLY BE AOB NORMAL WITH AN ABSENCE OF ANY ANOMALOUS WARMTH
UNDER THE GENERAL NW FLOW ALF.

SAT...SFC HI PRES UNDER SHRTWV RDG AXIS/AREA OF MID LVL DRY AIR
CROSSING THE UPR LKS SHOULD BRING DRY WX TO UPR MI. SOME SHOWERS
COULD ARRIVE LATE OVER NW PORTIONS OF LK SUP WITH PASSAGE OF SHRTWVS
THRU FAR NW ONTARIO AND ARRIVAL OF BAND OF DPVA/DEEP LYR QVECTOR
CNVGC/H85 THETA E ADVCTN INTO THAT AREA AHEAD OF ATTENDANT SFC COLD
FNT BY 00Z SUN...BUT WL MAINTAIN GOING DRY FCST FOR THE LAND CWA
WITH SFC HI PRES LINGERING OVER THE E HALF OF UPR MI AND DRY MID LVL
AIR/MID LVL SUBSIDENCE INVRN STILL IN PLACE THRU 00Z SUN. ALTHOUGH
THE 00Z GFS GENERATES SOME PCPN OVER THE INTERIOR W HALF IN THE
AFTN...ITS FCST SDNGS SHOW A MID LVL SUBIDENCE INVRN ABV WELL MIXED
PBL THAT WOULD FAVOR DRY WX. WITH H85 TEMPS REACHING ARND 15C OVER
THE W LATE IN THE AFTN...EXPECT HI TEMPS TO REACH THE LO 80S OVER
THE INTERIOR W.

SAT NGT THRU SUN...SHOWER CHCS WL INCRS AS BAND OF DPVA/DEEP LYR
QVECTOR CNVGC/HIER H85-5 RH ARRIVES FM THE NW TO THE SW OF SHRTWVS
CROSSING NW ONTARIO. VARIOUS MODELS SHOW SUBTLE DIFFERENCES IN
PLACEMENT/TIMING OF THESE DISTURBANCES/ASSOCIATED FORCING...SO WL
TEND TO RELY ON A CONSENSUS FCST. SINCE THE GUIDANCE INDICATES  AN
ABSENCE OF SGFNT H85 THETA E ADVCTN ON SAT NGT IN ADVANCE OF A SFC
COLD FNT APRCHG FM THE NW...ONLY LOWER CHC POPS ARE APPROPRIATE FOR
THAT PERIOD IN THE PRESENCE OF NOCTURNAL COOLING. WITH THE RETURN OF
DIURNAL HEATING/DESTABILIZATION ON SUN...WL GO WITH HIER CHC POPS
FOR SHOWERS/TS AS INDICATED IN PREVIOUS FCST ESPECIALLY OVER THE
SCENTRAL CWA...WHERE THE SFC FNT IS MORE LIKELY TO ARRIVE IN BETTER
SYNC WITH THE HEATING AND POSSIBLY INTERACT WITH LK BREEZE BNDRY OFF
LK MI. EXPECT THE LOWER MIN TEMPS ON SAT NGT TO BE OVER THE INTERIOR
E AND SCENTRAL CLOSER TO THE RETREATING DRY AIR/SFC HI PRES. MAX
TEMPS ON SUN ARE LIKELY TO REACH THE 70S AWAY FM LK COOLING WITH H85
TEMPS PEAKING AT 12-14C.

SUN NGT/MON...ALTHOUGH VARIOUS MODELS INDICATE OTHER SHRTWVS MAY DIG
SEWD INTO THE UPR LKS...OVERALL MID LVL DRYING IN THE WAKE OF THE
INITIAL DISTURBANCE/COLD FROPA RESPONSIBLE FOR THE SUN POPS SHOULD
LOWER THE POPS FOR THIS PERIOD. SEEMS THE BEST CHC FOR SHOWERS/TS
WOULD BE OVER THE SCENTRAL ON SUN EVNG IF THE INITIAL SHRTWV IS
SLOWER TO PASS. WL RETAIN SOME LO CHC POPS ON MON OVER MAINLY THE
SCENTRAL AWAY FM STABILIZATION OFF LK SUP TO ACCOUNT FOR THE CHC A
TRAILING SHRTWV WITHIN THE PREVAILING NW FLOW ALF IS STRONGER THAN
ANTICIPATED AND CAN INTERACT WITH SOME LK BREEZE BNDRYS. MAINTAINED
MENTION OF SOME FOG ON SUN NGT WITH MID LVL DRYING OVER SOME RA
MOISTENED LLVLS WITH LGT N WINDS OFF LK SUP.

EXTENDED...WL RELY ON MODEL CONSENSUS GIVEN PERSISTENT TRICKY NW
FLOW ALF/POTENTIAL FOR SHRTWVS TO TRACK THRU THE UPR LKS AND
GENERATE SOME SHOWERS/TS. BULK OF THE MODELS INDICATE HI PRES WL
DOMINATE MOST OF THE TIME...SO ANY POPS WL BE ON THE SCHC SIDE AND
MAINLY OVER THE SCENTRAL AWAY FM THE STABILIZING INFLUENCE OF HI
PRES THAT WL BE OVER LK SUP MUCH OF THE TIME EXCEPT WHEN AND IF A
STRONGER DISTURBANCE MIGHT PASS BY.
&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 709 AM EDT FRI AUG 1 2014

VFR CONDITIONS ARE EXPECTED TO PREVAIL AT ALL THREE TAF SITES OVER
THE NEXT 24 HOURS. AN UPPER LEVEL DISTURBANCE AND DAYTIME HEATING
WILL LEAD TO CLOUD DEVELOPMENT OVER CENTRAL UPPER MICHIGAN THIS
AFTERNOON. THIS MAY BE ENOUGH TO PRODUCE A SHOWER...BUT WITH THE
LAKE BREEZE EXPECTED TO BE THROUGH KSAW BY THAT TIME...THINK THE
SHOWERS WILL STAY TO THE SOUTH OF THE SITE. LAKE BREEZES WILL ALSO
DEVELOP AT THE OTHER TWO SITES THIS AFTERNOON.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 335 AM EDT FRI AUG 1 2014

WITH A WEAK PRESSURE GRADIENT TYPICAL OF SUMMER DOMINATING THIS
FORECAST PERIOD...EXPECT WINDS UNDER 15 KTS THROUGH TUE. ALTHOUGH
THERE WILL BE PATCHY FOG WITH RELATIVELY HUMID AIR OVER THE CHILLY
LAKE WATERS INTO MON...NO WIDESPREAD DENSE FOG IS LIKELY.
&&

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

$$

SHORT TERM...SRF
LONG TERM...KC
AVIATION...SRF
MARINE...KC





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