Severe Thunderstorm Warning 23, NWS Marquette, MI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
340 PM EDT SAT JUN 11 2005

.DISCUSSION...

UPPER LEVEL PATTERN FEATURES A WESTERN CONUS TROUGH AND LARGE E
CONUS SUBTROPICAL RIDGE WITH H5 HEIGHTS AROUND 592DAM CENTERED OFF
THE NC/SC COAST. IN BETWEEN...POCKETS OF SHORTWAVE ENERGY ARE RIDING
NNE OVR THE CNTRL CONUS ALONG N-S ORIENTED FRONT AND THIS IS
TRIGGERING SCATTERED CONVECTION FM OK INTO SD. POOL OF HIGHER
MOISTURE IS STATIONED OVR UPR LAKES WITH PWATS FM MPX TO APX RUNNING
175-200 PCT OF NORMAL. TS ARLENE HAS NEALRY MADE LANDFALL OVR SCNTRL
AL/FL PANHANDLE...WITH RADAR SHOWING ASSOCIATED PCPN ALREADY SURGING
INTO MIDDLE TN RIVER VALLEY THANKS TO SSE WINDS AT H85 OF 40-50KT.
AXIS OF SCATTERED SHOWERS AND THUNDERSTORMS LIFTED ACROSS AREA LATE
THIS MORNING INTO THE EARLY AFTN...BUT THESE HAVE SINCE SHIFTED INTO
LK SUPERIOR. A FEW SHOWERS OVR CWA ATTM BUT MAINLY SHORTWAVE RIDGING
IS YIELDING CALM CONDITIONS PRESENTLY. E UPR MI IS SEEING LIONS
SHARE OF SHRA/TS DUE TO LAKE BREEZE CONVERGENCE OVR N LWR MI.

EXPECT THE QUIET WX TO ONLY HOLD FOR NEXT COUPLE HOURS THOUGH AS TS
ARE ALREADY DEVELOPING OVR SW WI IN AREA WHERE INSTABILITY HAS BEEN
MAXIMIZED TODAY AND WHERE LARGE SCALE LIFT FM PLAINS SHORTWAVE IS
TEAMING TOGETHER. SPC WATCH BOX FOR ACTIVITY WITHIN A FEW COUNTIES
TO SW OF IWD AND THINK AS SHORTWAVE SHIFTS N THIS EVENING THE FAR W
UPR PENINSULA IS WHERE BEST CHANCE OF SHRA/TS WILL OCCUR. WARM FRONT
OVR WCNTRL WI WILL TRY TO MAKE RUN INTO FAR N WI/SW UPR MI EARLY
THIS EVENING. GOES DERIVED CAPE/CIN PRODUCTS INDICATES RIBBON OF
1000-1500J/KG CAPES (LESS THAN 20J/KG CIN) AHEAD OF TS ACROSS NW WI
INTO FAR SW UPR MI. ENOUGH CAPE FM 0-3KM TO JUSTIFY LARGE HAIL
THREAT ALTHOUGH THE NEAR 11000FT HEIGHT OF WB IS QUITE HIGH. ANY
LINE SEGMENT COULD PRODUCE LOCALIZED SVR WINDS AS DELTA THETA-E
VALUES NEAR 30C THIS EVENING. K-INDEX VALUES BTWN 30-35 ALSO SUPPORT
GOING HEAVY RAIN THREAT. GRIDS SHOW LIKELY POPS OVR FAR W THEN
TAPERING TO CHANCE INTO CNTRL/E ZONES. ACTUALLY LIKE 00Z WRF SOLN
WITH LINE OF CONVECTION COMING INTO SW ZONES THEN DIMINISHING
QUICKLY AWAY FM BETTER INSTABILITY. DECREASING TREND OVERNIGHT LOOKS
GOOD AS PRIMARY SHORTWAVE LIFTS N OF LK SUPERIOR...LEAVING ONLY SOME
WEAK ELEVATED INSTABILITY TO BE ACTED UPON BY ANY RENEGADE SMALL WAVES.
LEFT THE SLIGHT CHANCE POPS GOING UNTIL 13Z ON SUN.

MODELS CONTINUE TO TREND TOWARD MUCH DRIER MID LEVELS LATER SUN
WITH NO SHORTWAVES OF NOTE AND EVEN SHORTWAVE RIDGING PROGGED. SOME
LL CONVERGENCE POSSIBLE OVR FAR SE CWA. OTHERWISE...EVEN THOUGH AFTN
SBCAPES WILL LIKELY RISE WELL ABOVE 1000J/KG THINK THERE IS TOO MUCH
NEG DYNAMICS AND DRY MID LEVEL AIR TO JUSTIFY ANY POPS AWAY FM THAT
AREA. BLYR WINDS FM SW AT 15-25KT AND H85 TEMPS IN 15-17C RANGE
SHOULD ENSURE A VERY WARM DAY WITH MAX TEMPS RISING WELL INTO THE
80S FOR MOST AREAS.

MON FCST TIED TO WESTWARD EXTENT OF REMNANTS OF TS ARLENE. NAM STILL
FARTHER W THAN GFS WITH SURGE OF MOISTURE REMNANTS AND THEN MERGES
THIS ENERGY WITH APPROACHING SHORTWAVE TROUGH OVR NCNTRL CONUS.
BELIEVE THAT NAM SOLN IS A BIT AGGRESSIVE AND LIKE THE IDEA OF GFS
SHOWING MORE SPLIT BTWN THE TWO SOURCES OF MOISTURE/LIFT. STILL...
EVEN GFS DOES BRING PCPN INTO MOST OF CWA THROUGH THE EVENING INTO
THE OVERNIGHT. SO...EVEN THOUGH THINK NAM SOLN IS TOO BOISTEROUS
WITH QPF WENT AHEAD AND EXPANDED POPS INTO ALL CWA FOR THIS
PERIOD...JUST SMALL CHANCE THOUGH.

EXTENDED (TUE THROUGH SAT)...AN OMEGA BLOCK APPEARS IN THE OFFING BY
LATE IN THE UPCOMING WEEK. DEPENDING WHERE THE PRIMARY RIDGE AXIS
SETS UP IN THIS PATTERN UPR LAKES COULD END UP WITH DRY WX FOR A
LONG STRETCH STARTING LATE IN THE WEEK INTO NEXT WEEKEND. HOW WE GET
TO THE OMEGA BLOCK STILL UP FOR DEBATE. ECMWF/CANADIAN INDICATE UPR
LOW THAT SHIFTS ACROSS PLAINS WEAKENS AND IS ABSOLVED BY ENERGY
DROPPING INTO NORTHEAST CANADA. GFS/UKMET SUGGESTS THAT PLAINS
SYSTEM IS WHAT HELPS TO DEVELOP THE BLOCK. WV LOOP AND RAOBS
INDICATE THAT SYSTEM IS AGGRESSIVELY DIGGING INTO PAC NW ATTM.
CONSIDERING THIS AND STRENGTH OF UPSTREAM BLOCK OVR SE CONUS...THINK
RESULTING UPR LOW WILL BE SLUGGISH TO MOVE ACROSS CONUS THIS WEEK.
THEREFORE...PREFER SLOWER SOLNS OF ECMWF/CANADIAN INITIALLY.
EVENTUALLY RIDGE BEGINS TO REORIENT E TO W ALONG GULF COAST...SO UPR
LOW WILL PROBABLY START TO SHIFT EAST QUICKER THAN ECMWF SHOWS...PER
UKMET/CANADIAN. IN ALL THIS...THINK 00Z/06Z OPERATIONAL GFS IS TOO
QUICK AND TOO FAR NORTH WITH THE SYSTEM. AN EXAMPLE OF THIS IS BY
00Z WED WHEN GFS HAS UPR LOW CENTER OVR E CNTRL WI WHILE
ECMWF/UKMET/CANADIAN ARE CLUSTERED OVR N IA. BANKING ON THE FARTHER
S SOLN...EXPECT BEST CHANCE OF RAIN OVR S TIER OF ZONES TUE-WED.
AFTER THAT...RIDGING BEGINS TO BUILD IN. ECMWF IS SLOWER BUT STILL
FARTHER S AND EVEN THE GFS IS DRY FOR THU...SO REMOVED PCPN. DRY ON
OUT INTO THE WEEKEND AND PROBABLY BEYOND.

COORD WITH GRB.

&&

.MQT...WATCHES/WARNINGS/ADVISORIES...NONE.

&&

JLAA

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE MARQUETTE MI
525 PM EDT SAT JUN 11 2005

MIZ001>007-009>014-084-085-121200-
ALGER-BARAGA-DELTA-DICKINSON-GOGEBIC-IRON-KEWEENAW-LUCE-MARQUETTE-
MENOMINEE-NORTHERN HOUGHTON-NORTHERN SCHOOLCRAFT-ONTONAGON-
SOUTHERN HOUGHTON-SOUTHERN SCHOOLCRAFT-
525 PM EDT SAT JUN 11 2005

THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN AND CENTRAL UPPER
MICHIGAN.

.DAY ONE...TONIGHT AND SUNDAY

SCATTERED THUNDERSTORMS ARE POSSIBLE TONIGHT INTO EARLY SUNDAY.
THE BEST CHANCE OF THUNDERSTORMS WILL OCCUR OVER THE WESTERN HALF
OF THE UPPER PENINSULA THIS EVENING. THERE IS A CHANCE THAT SOME
STORMS THIS EVENING COULD BECOME SEVERE WITH HAIL UP TO AN INCH
IN DIAMETER AND WIND GUSTS TO 60 MPH. THUNDERSTORMS MAY ALSO
PRODUCE HEAVY RAINFALL RESULTING IN PONDING OF WATER ON ROADS AND IN
LOW-LYING AREAS.

THERE IS A SMALL CHANCE OF THUNDERSTORMS SUNDAY AFTERNOON EAST OF
GRAND MARAIS TO MANISTIQUE.

.DAYS TWO THROUGH SEVEN...SUNDAY NIGHT THROUGH SATURDAY

THUNDERSTORMS ARE POSSIBLE MONDAY NIGHT THROUGH TUESDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE NEEDED THIS EVENING.

ADDITIONAL WEATHER INFORMATION MAY BE OBTAINED AT THE FOLLOWING URL:

HTTP://WWW.WEATHER.GOV/MQT (ALL LOWER CASE)

JLA